U.S. patent application number 17/666765 was filed with the patent office on 2022-05-26 for combustible attic fire protection scheme.
The applicant listed for this patent is Firebird Sprinkler Company LLC. Invention is credited to Jeffrey J. Pigeon.
Application Number | 20220161081 17/666765 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-26 |
United States Patent
Application |
20220161081 |
Kind Code |
A1 |
Pigeon; Jeffrey J. |
May 26, 2022 |
COMBUSTIBLE ATTIC FIRE PROTECTION SCHEME
Abstract
A fire suppression system in which the water supply line is
fitted with repeating arrays or groups of sprinkler heads. Each
array is composed of at least two side-discharge sprinklers. The
side-discharge sprinklers in each array are aimed so that their
coverage areas point in opposite directions. Each side-discharge
sprinkler includes a lateral heat shield. The lateral heat shield
has a concave heat-concentering side that focuses radiant heat
toward the sprinkler's trigger, and a convex heat-scattering side
that disperses radiant heat away from the trigger. In some
embodiments, the array can include one or more vertical-discharge
sprinklers. The vertical-discharge sprinkler may include a heat
collector to facilitate early activation of its trigger. The fire
suppression system is advantageous in high-challenge applications
like facilities where large quantities of combustible items are
stored in close proximity, such as in warehouses and attics.
Inventors: |
Pigeon; Jeffrey J.; (Ann
Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Firebird Sprinkler Company LLC |
Ann Arbor |
MI |
US |
|
|
Appl. No.: |
17/666765 |
Filed: |
February 8, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16988870 |
Aug 10, 2020 |
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17666765 |
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16589283 |
Oct 1, 2019 |
10940350 |
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16988870 |
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16208649 |
Dec 4, 2018 |
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16589283 |
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15598808 |
May 18, 2017 |
10493308 |
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16208649 |
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15257961 |
Sep 7, 2016 |
10149992 |
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15598808 |
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14661302 |
Mar 18, 2015 |
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15257961 |
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62215058 |
Sep 7, 2015 |
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62019527 |
Jul 1, 2014 |
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61955253 |
Mar 19, 2014 |
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International
Class: |
A62C 35/68 20060101
A62C035/68; A62C 37/12 20060101 A62C037/12; A62C 31/02 20060101
A62C031/02; B05B 1/26 20060101 B05B001/26; A62C 37/11 20060101
A62C037/11; A62C 35/64 20060101 A62C035/64; A62C 3/00 20060101
A62C003/00 |
Claims
1. A fire protection system for a combustible concealed space, the
combustible concealed space comprising a pitched roof constructed
of a plurality of generally spaced apart structural members
extending downwardly and outwardly from a ridgeline of the roof to
an eave of the roof, the plurality of structural members defining
respective channels therebetween, and the fire protection system
comprising: a first row of sprinklers nearest the ridgeline, the
sprinklers being mounted to a first branch line extending generally
parallel to the ridgeline, wherein: (i) each sprinkler is
positioned within a respective channel, and (ii) consecutive
sprinklers along the first row are spaced having at least one
channel therebetween without a sprinkler of the first row
positioned therein, a second row of sprinklers extending generally
parallel to the first row of sprinklers, the second row of
sprinklers being positioned to spray in a downslope direction
predominately away from the first row of sprinklers, wherein: (i)
each sprinkler of the second row is positioned within a respective
channel, (ii) consecutive sprinklers along the second row are
spaced having at least one channel therebetween without a sprinkler
of the first row positioned therein, and wherein: each sprinkler of
the second row is axially offset with respect to each of the
sprinklers of the first row.
2. The fire protection system of claim 1, wherein the first row of
sprinklers is positioned below the ridgeline.
3. The fire protection system of claim 1, wherein each channel is
formed between adjacent rafters.
4. The fire protection system of claim 1, wherein each channel is
formed between adjacent trusses.
5. The fire protection system of claim 1, wherein horizontal
spacing between the first row of sprinklers and the second row of
sprinklers is approximately twenty-five feet or smaller.
6. The fire protection system of claim 1, wherein horizontal
spacing between the first row of sprinklers and the second row of
sprinklers is approximately twenty-five feet or larger.
7. The fire protection system of claim 1, wherein each sprinkler of
the first row of sprinklers is mounted to the first branch line
projecting upwardly therefrom.
8. The fire protection system of claim 1, wherein each sprinkler of
the first row of sprinklers includes a fluid deflector configured
to produce a generally elliptical spray distribution pattern.
9. The fire protection system of claim 1, wherein each sprinkler of
the second row of sprinklers directs water spray into the pitched
roof.
10. The fire protection system of claim 1, wherein each sprinkler
of the second row of sprinklers includes a fluid deflector facing
downslope.
11. The fire protection system of claim 10, wherein the deflector
is configured to produce a substantially downslope distribution
pattern.
12. The fire protection system of claim 1, further including a
third row of sprinklers extending generally parallel to the first
row of sprinklers, the third row of sprinklers being positioned to
spray in a downslope direction predominately away from the first
row of sprinklers, wherein: (i) each sprinkler of the third row is
positioned within a respective channel, and (ii) consecutive
sprinklers along the third row are spaced having at least one
channel therebetween without a sprinkler of the first row
positioned therein.
13. The fire protection system of claim 1, wherein each sprinkler
of the second row of sprinklers and each sprinkler of the third row
of sprinklers directs water spray into the pitched roof.
14. The fire protection system of claim 1, wherein each sprinkler
of the second row of sprinklers and each sprinkler of the third row
of sprinklers includes a fluid deflector facing downslope.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 16/988,870 filed Aug. 10, 2020, which is a Continuation of U.S.
application Ser. No. 16/589,283 filed Oct. 1, 2019, which is a
Continuation of U.S. application Ser. No. 16/208,649 filed Dec. 4,
2018, which is a Continuation-in-Part of U.S. application Ser. No.
15/598,808 filed May 18, 2017, which is a Continuation-in-Part of
U.S. application Ser. No. 15/257,961 filed Sep. 7, 2016, which
claims priority to Provisional Patent Application No. 62/215,058
filed Sep. 7, 2015, and is a Continuation-in-Part of U.S.
application Ser. No. 14/661,302 filed Mar. 18, 2015, which claims
priority to Provisional Patent Application No. 62/019,527 filed
Jul. 1, 2014 and to Provisional Patent Application No. 61/955,253
filed Mar. 19, 2014, the entire disclosures of which are hereby
incorporated by reference and relied upon.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention. The invention relates generally to
methods and systems for extinguishing fires, and more particularly
to sprinklers of such systems.
[0003] Description of Related Art. Fire suppression systems have
been used in the United States to protect warehouses and factories
for many years. In a fire suppression system, a fire sprinkler is
positioned near the ceiling of a room where hot "ceiling jets"
spread from a fire plume. When the temperature at an individual
sprinkler reaches a pre-determined value, a thermally responsive
trigger in the sprinkler activates and permits a flow of water
toward a deflector. The deflector spreads the water into thin
streams or "ligaments" that break up into droplets. The water
droplets deliver water over a wide coverage area. The water
droplets will directly combat fire burning within the coverage area
and will wet any surrounding materials not yet combusting.
Furthermore, the water droplets will cool the surrounding air
through evaporation and displace air with inert water vapor.
[0004] Examples of some fire suppression systems and methods of
installation are described in detail in my U.S. Pat. Nos. 8,602,118
(issued Dec. 10, 2013) and U.S. Pat. No. 8,733,461 (issued May 27,
2014), the entire disclosures of which are hereby incorporated by
reference and relied upon.
[0005] Some fire protection applications are considered to be more
challenging than others. For example, storage areas for goods, like
warehouses and attics, are commonly considered high-challenge
applications due to the likelihood of densely packed flammable
objects stored in relatively unattended areas. In addition, attics
may be further-complicated when that the framing structural members
are made of combustible wood and/or the roof decking is wood-based,
thereby effectively adding to the density of combustible items
stored in close proximity.
[0006] High-challenge fire applications like these and others would
benefit from a passive fire suppression system that is designed to
react to fires with direct heavy supplies of liquid water with
un-diminished volume and velocity. Such a system should not
over-tax the hydraulic efficiency of the supply system. To account
for high hydraulic drains, the common solution has been to increase
supply line capacity (i.e., pipe diameter) and/or the water supply
pressure. Unfortunately, both of these measures increase the
overall cost of a fire suppression system, not only in material
costs but also in labor of installation. Small businesses competing
for new jobs may find it difficult to bid some larger projects due
to the large working capital burdens that may be required. As a
result, competition is stifled, and costs rise.
[0007] An issue common in many attic applications involves location
of the sprinkler heads a rather large distance away from the ridge
or peak of the roof. Installation specifications provided by
manufacturers of most attic-specific sprinkler heads indicate a
required minimum spacing below the ridge or peak of the roof so
that an adequate spray distribution pattern has opportunity to
develop. These spacing requirements severely limit the installation
layout options and fails to take advantage of the concentration of
heat that accumulates at the roof ridge in the event of fire.
[0008] There is therefore a need in the fire suppression and
extinguishment field to create an improved fire sprinkler system
for high-challenge applications that delivers a maximum density of
water per unit area of ground, that maximizes hydraulic
efficiencies, that improves discharge control of sprinkler heads,
and that is cost effective so that working capital burdens are
manageable.
BRIEF SUMMARY OF THE INVENTION
[0009] A fire suppression system is configured to disperse a liquid
water over a storage area. The system comprises an elongated
tubular supply line configured as a conduit to carry pressurized
liquid water. The supply line has a longitudinal centerline and
right and left sides separated by a vertical plane passing through
the longitudinal centerline. A plurality of fire sprinklers are
coupled directly to the supply line. Each the fire sprinkler is
configured to receive an outflow of liquid water from the supply
line. The plurality of fire sprinklers are arranged in
substantially identical repeating arrays of three fire sprinklers.
Each the array comprises right and left side-discharge fire
sprinklers and a vertical discharge fire sprinkler. The right and
left side-discharge fire sprinklers are arranged so that the right
side-discharge fire sprinkler is disposed on the right side of the
supply line to discharge liquid water generally perpendicularly
away from the longitudinal centerline in a rightward direction, and
the left side-discharge fire sprinkler is disposed on left side of
the supply line to discharge liquid water generally perpendicularly
away from the longitudinal centerline in a leftward direction. The
vertical-discharge fire sprinkler is arranged to discharge liquid
water generally along the vertical plane.
[0010] This present invention enables the advantageous combination
of multiple orientations of fire sprinklers, thus combining the
respective strengths of each to improve fire protection while at
the same time saving both material and labor. Furthermore, the
novel combining of multiple orientations of fire sprinklers
eliminates certain weaknesses inherent in each orientation by
itself. As a result, the fire suppression system and method harness
the working power of working of multiple orientations of fire
sprinklers to produce, in effect, a super fire sprinkler system and
method. The fire suppression system is advantageous in
high-challenge applications like facilities where large quantities
of combustible items are stored in close proximity, such as in
warehouses and attics. In high-challenge applications that are
further complicated by combustible framing members and/or
combustible roof decking, as in pitched-roof attics, the right and
left side-discharge fire sprinklers can if desired be positioned in
close proximity to the peak so as to discharge liquid water with a
beneficial hose stream effect that wets the combustible structural
members with a high-velocity water stream that helps prevent the
fire from growing. This high-velocity wetting effect can, if
desired, be designed to use a pitched roof or other nearby
structures as a secondary deflector to enable highly-customized
water distribution options.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] These and other features and advantages of the present
invention will become more readily appreciated when considered in
connection with the following detailed description and appended
drawings, wherein:
[0012] FIG. 1 is a simplified perspective view of a building
interior in which are installed prior are side-discharge sprinklers
along opposing faces of structural beams;
[0013] FIG. 2 is a cross-sectional view taken generally along lines
2-2 of FIG. 1;
[0014] FIG. 3 is a perspective view of a building interior as in
FIG. 1 but fitted a fire suppression system according to one
embodiment of the present invention;
[0015] FIG. 4 cross-sectional view as taken generally along lines
4-4 of FIG. 3 showing of a section of supply line supporting two
side-discharge fire sprinklers arranged in opposite-facing
directions and where the deflector of one fire sprinkler is in
partial cross-section;
[0016] FIG. 5 is a perspective view of the section of supply line
shown in FIG. 4 again with the deflector of one fire sprinkler
depicted in partial cross-section;
[0017] FIG. 6 is a simplified view of the present fire suppression
system in which one side has been activated to suppress a fire
below;
[0018] FIG. 7 is a perspective view showing the sprinkler system of
one embodiment installed above stored items and with two fire
sprinkler heads activated in response to heat rising from the flues
in-between the stored items;
[0019] FIG. 8 is a top view showing two parallel supply lines
arranged over a row of stored items, each supply line being fitted
with opposite-facing sprinkler heads according to one embodiment of
the present invention, and further illustrating exemplary spray
discharge patterns from several of the sprinkler heads to
illustrate an exemplary coverage strategy;
[0020] FIG. 9 is a view as in FIG. 8 but further superimposing a
prior art fire suppression system comprising four supply lines with
omni-directional heads arranged in the common 10'x10' grid pattern
for comparison purposes;
[0021] FIG. 10 is a perspective view as in FIG. 4 but showing an
optional adjustment scheme whereby the coverage patterns can be
individually adjusted to suit the storage conditions;
[0022] FIG. 11 is a cross-sectional view of a three-head array
portion in a fire suppression system comprising two
oppositely-facing side-discharge sprinklers and one
vertical-discharge sprinkler, according to one embodiment of the
present invention;
[0023] FIG. 12 is a bottom view of the vertical-discharge sprinkler
depicted in FIG. 11;
[0024] FIG. 13A is a simplified view of the three-head array
disposed within a warehouse above an uncontained fire, and in which
the vertical-discharge sprinkler and one side-discharge sprinkler
have been activated by elevated temperature to suppress the
fire;
[0025] FIG. 13B is a simplified view of the three-head array
disposed within an attic space and arranged so that the sprinklers
discharge in-between trusses or rafters;
[0026] FIG. 13C is a view of an attic installation similar to FIG.
13B and showing various placement options relative to the roof peak
in combination with adjustable side-discharge deflectors to enable
the roof surface to be utilized as a secondary deflector if
desired;
[0027] FIGS. 13D is an enlarged view of the three-head array of
FIG. 13C with one side-discharge deflector shown in different
adjusted positions;
[0028] FIG. 14 is a simplified Temperature-Time graph illustrating
the temporal responsiveness for two activated sprinkler heads shown
in either of FIGS. 13A or 13B;
[0029] FIG. 15 is a top view as in FIG. 8, in which two parallel
supply lines are arranged over a row of stored items, and each
supply line supporting sequentially-repeating arrays of three
sprinkler heads, in which for each array the two side-discharge
sprinklers are staggered from one another and the
vertical-discharge sprinkler is located directly below one of the
side-discharge sprinklers;
[0030] FIG. 16 is top view like FIG. 15 but of yet another
alternative configuration in which each three-head array comprises
two side-discharge sprinklers located directly opposite one another
in back-to-back fashion and the associated vertical-discharge
sprinkler is spaced about one-half the interval distance to the
side-discharge sprinklers in the next adjacent array;
[0031] FIG. 17 is top view like FIGS. 15 and 16 but of yet another
alternative configuration in which the vertical-discharge sprinkler
and two side-discharge sprinklers in each three-head array are all
axially-spaced from one another along the supply line;
[0032] FIG. 18 is a cross-sectional view as in FIG. 11 but showing
another variation of the system in which the vertical-discharge
sprinkler head is configured to provide water discharge at two
unequal flow rates;
[0033] FIG. 19 is a bottom view of the vertical-discharge sprinkler
in FIG. 17, and further showing an optional non-circular deflector
configuration;
[0034] FIG. 20 is a top view as in FIG. 16 in which the
vertical-discharge sprinklers are each configured to produce
non-circular spray patterns;
[0035] FIG. 21 depicts yet another alternative embodiment in which
the vertical-discharge sprinkler has a traditional frame structure
with a trigger in the form of a heat-sensitive glass bulb;
[0036] FIG. 22 is a perspective view as in FIG. 7 but showing an
alternative embodiment in which the supply line is located within
the longitudinal flue of a storage rack and the repeating arrays of
three-head sprinkler groups are coordinated with the locations of
the transverse flues so as to maximize water placements in the flue
corridors;
[0037] FIG. 23 is a perspective view of a lateral heat shield
according to one exemplary embodiment showing its concave
heat-concentrating side;
[0038] FIG. 24 is a different perspective view of the lateral heat
shield of FIG. 23 showing its convex heat-scattering side and
connector feature;
[0039] FIG. 25 is cross-sectional view of a three-head array
similar to FIG. 21 but showing lateral heat shields operatively
associated with each of the right and left side-discharge
sprinklers;
[0040] FIG. 26 is a simplified view of the three-head array of FIG.
25 exposed to a laterally-offset fire, and in which the right
side-discharge sprinkler is prompted to early activation by the
concentrated effects of radiant heat and the left side-discharge
sprinkler will experience delayed activation by the scattering of
radiant heat;
[0041] FIG. 27 is cross-sectional view as in FIG. 25, but where the
left side-discharge sprinkler is axially offset from the right
side-discharge sprinkler, and the vertical discharge sprinkler is
provided with a heat collector;
[0042] FIG. 28 is a fragmentary perspective view of an alternative
embodiment wherein two three-head arrays are supported along a
common supply line, with the side-discharge sprinklers set at
downwardly skewed angles and the lateral heat shields are
configured with fused pedals to create dish-like reflection
surfaces;
[0043] FIG. 29 is yet another alternative embodiment of the lateral
heat shield configured to facilitate controlled down-spray without
sacrificing heat reflection properties; and
[0044] FIG. 30 shows a vertical-discharge sprinkler oriented
vertically pointing up.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Referring to the figures, wherein like numerals indicate
like or corresponding parts throughout the several views, a fire
suppression system according to one exemplary expression of the
present invention is generally shown at 20 in FIGS. 3-9. In FIG. 3,
the fire suppression system 20 is shown located in the interior
storage space of a building structure. The building structure may
be a warehouse or attic or other form of storage space having a
floor 22, and at least three beams 24 suspended over the floor 22.
The beams 24 can be steel I-shaped beams, trusses, rafters or any
suitable structural member made from any suitable material and
shaped in any suitable manner. For example, in FIG. 13B the beams
24 are depicted in the form of trusses or rafters. The beams 24 are
typically arranged parallel to one another and spaced evenly apart
by an interior bay length L1. In the example of FIG. 3, the three
beams 24 may be consider first, second and third beams 24, with the
second beam being disposed in between the first and third beams 24.
Beams 24 are typically supported by vertical uprights, which can be
posts or walls or other suitable structure. FIG. 3 depicts the
vertical uprights in the form of posts 26 spaced apart from one
another by an interior bay width W1. In some constructions, purlins
(not shown) may be placed perpendicularly across the beams 24 to
support a ceiling or roof 27. In the example of FIG. 3, the ceiling
or roof 27 is oriented at a skewed or pitched angle relative to the
floor 22, however flat roof constructions are also certainly
possible as suggested by FIG. 6. To be clear, the construction of
the roof 27 is not critical; the principles of this invention will
apply to pitched, sloped, flat, hip and possibly any other type of
roof structure. In the case of sloped and pitched roofs 27, the
beams 24 are usually oriented to run perpendicular to the
high-point of the roof 27 which, in FIG. 3, is illustrated in the
form of a ridge 28. That is to say, the pitch of the roof 27
typically runs parallel to the beams 24 and parallel to the W1
dimension. In steel frame structures like those depicted in FIGS. 1
and 3, the regions between adjacent beams 24 and spanning their
full width are referred to as bays. Each bay is therefore defined
by the above-noted length and width variables L1 and W1. Commonly,
the bay width W1 is at least 20 feet (6 m) and the bay length L1 is
at least 20 feet (6 m), although often one or both of these
measures are greater. The pitch of the roof 27 slopes along the bay
width W1. In the case of residential attics and other types of
structures where the beams 24 take the form of rafters or trusses,
the bay length L1 may be considerably shorter.
[0046] The fire suppression system 20 includes at least one supply
lines 30, and in some cases a plurality of supply lines 30. Each
supply line 30 comprises a fluid-conducting conduit or pipe
suspended below the roof 27 of the structure, such as from its
purlins (not shown) or by other suitable accommodation. The one or
more elongated tubular supply lines 30 within a building structure
are fed with pressurized liquid water, such as water or other
suitable material, from a source under pressure, typically in the
range of about 30-200 psi. The supply lines 30 may be located in
the middle space between two structural beams 24 (or girders,
trusses, rafters, etc.) in the building structure. That is, the
supply lines 30 are advantageously located generally along the
centerline of each bay area, with one supply line 30 per bay,
however these are not requirements and other configurations are
certainly possible. Therefore, in applications with multiple supply
lines 30, the supply lines 30 are arranged generally parallel to
one another under the roof 27 so that they all extend perpendicular
(or at least not parallel) to the ridge 28 or other high point
feature of the roof 27 in the case of sloped/pitched roofs. Many
alternate arrangements are also possible, including supply lines 30
are arranged generally parallel to the ridge 28 or high point, or
skewed relative to the high point, or in the case of flat roofs
have some other strategic orientation.
[0047] Each supply line 30 has a longitudinal centerline A with
right C and left B sides separated by an imaginary vertical plane P
that passes through the longitudinal centerline A, as shown in
FIGS. 4 and 5. In situations where multiple supply lines 30 are
used, one supply line 30 may be deemed a first supply line 30 and
the next adjacent supply line a second supply line 30. The second
supply line 30 is typically disposed parallel to the first supply
line 30 and is perpendicularly spaced to either the left B or the
right C therefrom. The first and second supply lines 30 may be
generally identical to one another such that which is the first and
which is the second is of little consequence. Because the first and
second supply lines are next to one another, the right-side C of
one will face the left side B of another.
[0048] Side-discharge style fire sprinklers 32, sometimes referred
to herein as a sprinkler head or merely a head, are part of an
installed active fire suppression system disposed in a warehouse,
attic, shed or other high-challenge type of storage space needing
an elevated level of fire protection capability. The fire
sprinklers 32 are disposed in series along each supply line 30 at
regular intervals. In some applications, the interval spacing may
be about two-to-ten feet depending on design criteria. In the
accompanying illustrations, each fire sprinkler 32 is shown a
relatively short distance, e.g., two-feet, from the next adjacent
sprinkler head 32 on the same supply line 30, although the adjacent
sprinkler heads 32 are aimed in opposite directions. Greater or
lesser spacing are of course possible depending on the application.
In the examples of FIGS. 3-10, each fire sprinkler 32 is of the
side discharge type; none are vertical types. That is, the
sprinkler heads 32 in these embodiments are designed to be attached
to the supply line 30 so that they extend outwardly in a horizontal
or generally horizontal (i.e., non-vertical) direction. Typical
prior art side discharge sprinkler heads disperse water over a
generally semi-circular area. While standard prior art side
discharge sprinkler heads are suitable for use with the present
invention, in the preferred embodiment the sprinkler heads 32 are
specially configured to disperse water over a long, narrow,
well-defined, coverage area 64 which many be elliptical, oval or
rectangular.
[0049] The plurality of fire sprinklers 32 are arranged along a
common supply line 30 so that half of the fire sprinklers are
disposed on the right-side C of the supply line 30 and the other
half of the fire sprinklers 32 are disposed on left side B of the
supply line 30. At the location where each fire sprinkler 32 is
intended to adjoin the supply line 30, a saddle 34 is fitted in
place. Each saddle 34 perpendicularly intersects the supply line
30. The saddle 34 is provided with a central aperture (not visible)
that fluidly connects with the internal conduit region of the
supply line 30 so that an outflow of liquid water can travel from
the supply line 30 into the central aperture when the sprinkler
head 32 is activated. The surrounding body of the central aperture
has a threaded interior surface that is designed to mate with
external threads of the sprinkler 32. During fabrication of a fire
suppression system, an installer will typically drill holes in the
supply line 30 at the locations where fire sprinklers 32 are
desired. Half of the holes will be drilling on the left side L, and
the other half on the right-side R of the supply line 30. Saddles
34 are then welded or otherwise sealed to the supply line 30 over
the drilled holes. Finally, fire sprinklers 32 are screwed into
respective saddles 34 prior (or subsequent) to hanging the supply
line 30 from the supporting structure in the warehouse or other
building structure similar to that shown in FIG. 3.
[0050] Two supply lines 30 are illustrated in FIG. 3, which for
purposes of discussion may be referred to as the first and second
supply lines 30. The spacing between the first supply line 30 and
the second supply line 30 is approximately equal to the bay length
L1 of either bay. Because of the wide spacing between adjacent
first and second supply lines 30 enabled by this invention, as will
be described below in connection with FIGS. 8 and 9, the installer
is afforded substantially greater freedom to locate supply lines 30
far from the beams 24 which might otherwise present an obstruction
to the spray pattern. FIG. 3 represents a scenario where the supply
lines 30 are set so that only one supply line 30 is between each
adjacent pair of beams 24. This represents a substantial reduction
in the number of supply lines 30 to be installed as compared with
prior art systems, and therefore a significant reduction in
system/installation costs and long-term maintenance expenses, as
well as an improvement in fire suppression performance.
[0051] The fire suppression system 20 shown in FIGS. 3-9 depicts
use of a special application listed side-discharge-type sprinkler.
The side-discharge sprinkler 32 includes a threaded nipple 36 that
is configured with external thread forms to be screwed into a
threaded female saddle 34. A frame 38 is supported from the nipple
36. The frame 38, in turn, supports a trigger 40 and a deflector.
The deflector can be any device that shapes the dispersion of
water, including nozzle-like elements as well as more traditional
deflecting and diffusing features. In the illustrated examples, the
deflector includes an elongated, nozzle-like hood 42 having a
downward slant to efficiently direct water flow so as to achieve a
desired coverage area with minimal splash or turbulence. The
thermally responsive trigger 40 is at least partially shrouded by
the hood 42. That is to say, the hood 42 provides shelter for the
trigger 40. The deflector also includes an optional baffle 44. The
baffle 44 in these examples is a thin, strip-like element that is
supported below the hood 42. The baffle 44 is somewhat cantilevered
and arranged to extend outwardly with the hood 42, i.e.,
perpendicular to the supply line 30. The width of the baffle 44 is
considerably less than the interior width of the hood 42 so that a
substantial quantity of discharged water will flow unaffected
around the sides of the baffle 44. In use, the baffle 44 provides
at least two beneficial functions. Prior to activation of a fire
sprinkler 32, the baffle 44 provides a measure of passive
protection to the thermally responsive element 40 from the spray of
an adjacent sprinkler 32 so as to reduce the possibility of cold
soldering. In cases where an adjacent sprinkler 32 is earlier
activated, the incoming fluid spray will be at least partially
deflected by the baffle 44. After activation of a fire sprinkler
32, the baffle 44 assists like a dynamic flow control vane to help
evenly distribute liquid water within the coverage area. The
deflector is also shown including a downwash section 46 which, like
the baffle 44, also acts as a splash shield and helps evenly
distribute liquid water within the coverage area below the supply
line 30. Naturally, the deflector shown in the accompanying Figures
may be highly modified with additional flow controlling features in
order to achieve a well-defined coverage area 64 with water density
distribution characteristics as may be desired.
[0052] A duct extends through the nipple 36 to create an internal
flow path for water or other fire suppressing substance from the
supply line 30 along an outflow axis. The outflow axis is generally
perpendicular to the longitudinal extent of the supply line 30, and
in one preferred embodiment is generally horizontal. That is to
say, the outflow axis may be generally parallel to the floor 22,
however as suggested in phantom in FIG. 4 the outflow axis may be
skewed from horizontal in certain applications as a means to
achieve the desired spray coverage area 64. A plug-like closure
element that is mated with the trigger 40 blocks the duct until
activated by an elevated internal building temperature. Once the
trigger 40 is tripped, the closure is ejected and water (or other
substance in the supply line 30) rushes out under pressure through
the duct along the outflow axis and collides with the deflector to
spray over a non-circular individual coverage area 64. The trigger
40 is a thermally responsive element that responds to heat from a
fire plume and then releases the closure, thereby permitting the
flow of the fire suppressing or extinguishing substance. The
thermally responsive element may be a fusible link assembly
comprised of two link halves which are joined by a thin layer of
solder. When the rated temperature is reached, the solder melts and
the two link halves separate, allowing the sprinkler 32 to activate
and water to flow. Alternatively, the trigger 40 may be of the
glass bulb type which is designed to shatter when the rated
temperature is reached, or any other suitable device or method. The
trigger 40 may include any suitable method or device to block the
flow of the fire suppressing or extinguishing substance through the
duct until activated.
[0053] As stated above, on any given supply line 30, half of the
sprinklers 32 are placed on the right-side C and the other half on
the left side B. The plurality of fire sprinklers 32 are arranged
in alternating fashion on the right C and left B sides of the
supply line 30 such that every other fire sprinkler 32 is disposed
on the right-side C of the supply line 30 with the other fire
sprinklers 32 disposed on the left side B of the supply line 30.
Thus, every other side-discharge-type sprinkler 32 is set in an
opposite-facing direction along the same supply line 30. In this
arrangement, any two adjacent sprinklers 32 may be considered a
pair with one of the sprinklers 32 pointing left and the other fire
sprinkler 32 pointing right. The pair of fire sprinklers 32 may be
identical to one another or distinct. The drawings describe the
embodiment where the sprinklers 32 on the left side B are
longitudinally offset from the sprinklers 32 on the right-side C.
However, in another contemplated application the sprinklers 32 are
located in direct back-to-back relationship.
[0054] In order to put this opposite-facing arrangement into
effect, the saddles 20 of the respective sprinklers 32 are fixed on
horizontally opposite sides of the same supply line 30, so that
their respective outflow axes each perpendicularly intersect the
supply line 30. As shown by the phantom lines in FIG. 4, it is
contemplated that one saddle 34 (or both) may be placed so that the
sprinkler 32 extends at a skewed angle relative to horizontal as an
alternative to bending or otherwise adjusting the position of the
hood 42. Indeed, some applications may lend themselves to orienting
the two opposite-facing sprinkler heads 32 at different angles
relative to horizontal. As an example, the right-side sprinkler
head 32 may be angled 5 degrees below horizontal, and the left side
sprinkler 32 angled 10 degrees below horizontal in order to aim the
sprayed water relative to the overall height and location of any
stored items.
[0055] In order to address the potential of cold soldering due to
two sprinkler heads 32 being located so close to one another, it
may in some applications be desirable to place at least one
blocking surface in-between the two fire sprinklers 32. The
blocking surface may be configured as a component of the fire
suppression system 20 that is supported by the supply line 30 or by
a component (e.g., a sprinkler head 32) which in turn is supported
by the supply line 30, rather than comprising a feature of the
building structure like that shown in FIGS. 1 and 2. The blocking
surface could be configured to block liquid water that is
discharged from one of the fire sprinklers 32 from contacting the
other fire sprinkler 32 so that the trigger 40 of the second fire
sprinkler 32 is not delayed from activating in a timely fashion. A
blocking surface may take many different forms to facilitate the
close-spacing of side-discharge sprinklers 32 so that spray from
one sprinkler 32 does not over-cool an adjacent un-activated
sprinkler 32 and thereby delay its activation. The blocking
surfaces should be designed so that all of the side-discharge
sprinklers 32 operate essentially independent of one another and
fully according to their design specifications.
[0056] In the illustrated embodiments, the shape of the deflector
in which the trigger 40 is substantially shrouded and enclosed
forms a type of blocking surface. Indeed, the trigger 40 is only
exposed from the discharge end of the deflector and from below,
where a gap in the downwash member 46 is provided. This distinctive
configuration allows heat rising from a fire to directly enter the
deflector and be channeled toward the trigger 40. The deflector in
fact collects and concentrates the heat onto the trigger 40 thereby
encouraging early activation. However, the trigger 40 is otherwise
shrouded from water spray caused any other nearby sprinklers 32. As
a result, the possibility of cold soldering is substantially
reduced or eliminated.
[0057] In this manner, the deflector creates a cave-like shell
around the sides and top of the trigger 40; only the discharge
direction and the bottom of the cave-like enclosure are open.
Accordingly, the blocking surface fulfills several functions
simultaneously to enable effective use of side-discharge-type
sprinklers arranged on opposite-facing sides of the same
supply-line 30 in a warehouse application. These include acting as
a splash guard to prevent water that sprays sideways or rearwardly
(e.g., in response to contact with an obstruction) from reaching
the trigger 40 of a nearby sprinkler 32, reflecting heat onto the
unactuated trigger 40 of the sprinkler 32 so that the trigger 40
will activate in a timely fashion if/when needed, and shaping the
water flow to achieve a desired coverage area 64 and water density
distribution.
[0058] In another contemplated variation (not shown), a standard
prior art side-discharge sprinkler head is used and a blocking
surface in the form of a backer plate can be associated with each
sprinkler head. The backer plate could be a formed sheet-metal
member and arranged to overhang the sprinkler like a small roof.
Such a backer plate could be integrated with the deflector and/or
the frame of a sprinkler head. In any event, the backer plate
should be effective to negate the condition known as cold-soldering
that could otherwise arise in the event a first sprinkler is
set-off prior to the second sprinkler.
[0059] FIG. 6 shows two side-discharge sprinklers 32 arranged
opposite-facing directions above a bay area between two adjacent
beams 24 and covered by a roof 27. In this illustration, a fire has
broken out on the right side of the bay area below the fire
suppression system 20, setting off the right side-discharge
sprinkler 32 but not the left side-discharge sprinkler 32. As water
(or other liquid substance) sprays from the right side-discharge
sprinkler 32, the blocking surface associated with the right
side-discharge sprinkler 32 deflects the water spray so that it
cannot contact the left side-discharge sprinkler 32. Meanwhile, the
left side-discharge sprinkler 32 is poised to activate in a timely
fashion if/when needed. This ready condition of the left
side-discharge sprinkler 32 is passively facilitated by its
associated blocking surface. In particular, the blocking surface of
the left side-discharge sprinkler 32 acts as a shield that prevents
collateral overspray and water splashes from contacting its
unactuated trigger 40 (i.e., to prevent cold-soldering).
Furthermore, the blocking surface of the left side-discharge
sprinkler 32 reflects and funnels heat from the fire toward its
trigger 40 so that its activation timing is not adversely affected
(i.e., delayed) by the ambient water spray from the right
side-discharge sprinkler 32.
[0060] In FIG. 7, stored items 54 are shown disposed on the floor
22 in the warehouse. In a warehouse, stored items 54 are frequently
stacked or arranged in long rows. Also commonly, the stored items
54 may be stacked in elongated storage racks, generally indicated
at 56, which in turn are disposed on the floor 22 in the warehouse.
In FIG. 7, one such storage rack 56 is shown. Commonly, a warehouse
facility will arrange many storage racks 56 in opposite-facing
pairs separated by aisles large enough for a forklift to maneuver.
The common storage rack 56 has a plurality of shelves 58 upon which
are placed the stored items 54. Oftentimes, the stored items 54 are
palletized, or otherwise carried on standard 4x4 pallets to
facilitate handling with a forklift (no shown). Of particular note
is the overall height of the stored items 54 either standing free
or when arranged in rows. When stored items 54 are stacked in
shelves 58 of the storage racks 56, the lofty stored items 54 on
the uppermost shelf 56 will define the overall height, which is the
highest level or region of goods that must be protected by the fire
suppression system 20.
[0061] Within this context, the fire suppression system 20 is
suspended from above in the warehouse, at an elevation that is
greater than the overall height of the stored items 54 disposed
below. In the event of a fire, wherein it is presumed that the
locus of the fire is in or at a storage item 54 somewhere in a
storage rack 56. The arrangement of storage racks 56 and the
typical placement of palletized stored items 54 on the various
levels of shelves 58 in the storage racks 56 establish a plurality
of transverse flues 60 and one longitudinal flue 62. These flues
60, 62 are indicated by wide directional arrows. Naturally, such
flues 60, 62 can exist in solid-pile (non-racked) type storage
arrangements. The transverse flues 60 are formed in the gaps
between adjacent stored items 54. The longitudinal flue 62 is
created in the gap between two storage racks 56 when arranged
back-to-back. The importance of these flues 60, 62 becomes relevant
when a fire is present in or adjacent one of the stored items 54.
Perhaps a worst-case scenario in terms of fire suppression is when
a fire originates between two storage racks 56 arranged
back-to-back (i.e., in the longitudinal flue 62 area) at or near
the floor 22, which is suggested by heat arrows rising from the
flues 60, 62 in FIG. 7. This is the most distant and difficult to
reach region for liquid water dispersed from a fire sprinkler
32.
[0062] The fire produces hot combustion gases that travel upwardly
through the narrow flues 60, 62 like chimneys. When the escaping
heat is sufficient to activate at least one nearby overhead fire
sprinkler 32, water (or other liquid fire suppressing agent) will
be discharged. In order to be effective, the water must travel down
the very same flues 60, 62 through which heat from the fire is
rising up. The rising heat, concentrated within the narrow
passageways of the flues 60, 62, will tend to vaporize the
descending water spray unless sufficient quantities of water and/or
large enough droplet sizes can be applied to overpower the heat.
The greatest success at fire suppression will be achieved when, at
the initial stages of a fire, a maximum amount of water is applied
in a tightly-focused stream at high velocity to the flues 60, 62
directly above the fire locus.
[0063] The present fire suppression system 20 is configured and
arranged so that, at all stages of a fire but particularly at the
initial stages, a maximum amount of water is applied in a jet
stream, i.e., with relatively high velocity and narrow spread, to
the flues 60, 62 laying directly above the fire so that very little
spray is wasted dousing nearby (non-burning) stored items 54.
Furthermore, the fire suppression system 20 is capable of
generating a water curtain effect that resists spread of the fire
to adjacent storage racks 56. In the event of fire in a storage
rack 56, the activated fire sprinklers 32 will create a beneficial
water curtain in the adjacent aisles and/or flues 60, 62 to
discourage fire spread, thereby helping to contain the fire in the
smallest possible region. This invention is uniquely designed to
combat fires in high-challenge storage settings, including
warehouses and attics, where items 54 are tightly stacked or
arranged and water from activated fire sprinklers 32 must travel
into narrow flues 60, 62 to reach a fire.
[0064] FIG. 8 is a simplified top view of a fire suppression system
20 according to one embodiment of this invention where two adjacent
supply lines 30 (i.e., first and second) are disposed in a building
structure, perhaps arranged along the centerlines of two adjacent
bay areas between three adjacent beams 24 like that shown in FIG.
3. As an example, the spacing between the two adjacent supply lines
30 may be about twenty-five feet. Of course, an installer or a
qualified spec writer may decide that the spacing between the two
adjacent supply lines 30 should be larger or smaller. Each
sprinkler head 32 is schematically illustrated and arranged in the
alternating fashion with blocking surfaces protecting its trigger
40. Furthermore, if one were to rotate FIG. 8 ninety degrees in a
counter-clockwise direction, the left-hand supply line 30 could be
considered the "first" and the right-hand supply line 30 the
"second." It is then evident that the fire sprinklers 32 on the
right-side C of the first supply line 30 face toward the second
supply line 30. And similarly, the fire sprinklers 32 on the left
side B of the second supply line 30 face toward the first supply
line 30. In other words, the fire sprinklers 32 on the left side B
of the second supply line 30 point toward the fire sprinklers 32 on
the right-side C of the first supply line 30 somewhat like the
cannons of two ancient battleships.
[0065] As stated previously, each fire sprinkler 32 is configured
to disperse an outflow of liquid water like a fire hose over a
non-circular individual coverage area 64. The coverage areas 64 are
represented by broken lines in FIGS. 7-9, as may be understood as
the point of contact with the uppermost surfaces of stored items 54
located on the highest elevation shelves 58 in the storage racks
56. Standard prior art side-discharge sprinkler heads, which are
usually intended for wall-mounted applications, typically disperse
water over a generally semi-circular area. While standard prior art
side discharge sprinkler heads are suitable for use with the
present invention, in the preferred embodiment the deflectors are
configured so that the coverage areas 64 are more elongated in
shape. The non-circular individual coverage areas 64 from any
paired fire sprinklers 32 are contiguous and generally mirrored. If
any paired fire sprinklers 32 are placed directly back-to-back
along the supply line 30, then their combined coverage areas 64
would merge and define a generally elliptical or oval or
rectangular area. However, in the illustrated examples paired fire
sprinklers 32 are longitudinally offset along the supply line 30 so
that their respective coverage areas 64 are likewise offset, as
well as focused in opposite directions, as shown in the lower
right-hand corner of FIG. 8.
[0066] The coverage area 64 from each sprinkler head 32 has a major
diameter L2 which is generally perpendicular to the supply line 30
and a shorter minor diameter W2 that is generally parallel to the
supply line 30. While the terms "major diameter" and "minor
diameter" are suggestive of elliptical geometries, and indeed
several of the Figures depict elliptical shapes, coverage areas
could have oval or rectangular geometries, or other suitable shape
as may be deemed acceptable. The minor diameter W2 may be between
about 5% and 100% of the major diameter L2, and in some preferred
embodiments W2 is between about 15% and 67% of L2. More
specifically, W2 may be less than 50% of L2 in order to produce a
discharge jet that more closely mimics the powerful stream from a
fire hose. The major diameter L2 may be smaller than the
perpendicular spacing between the first and second supply lines 30,
and also slightly larger than half the distance between adjacent
supply lines 30 to account for some degree of overlap. So, in the
example of FIG. 8 where the distance between adjacent supply lines
30 is shown as about twenty-five feet, the L2 may be somewhat
greater than twelve-and-a-half feet--perhaps about fourteen feet.
Every other sprinkler head 32 located along the same supply line 30
is spaced apart by a spacing distance S. That is to say, when
considering only the sprinkler heads 32 on one side (left B or
right C) of the supply line 30, the separation intervals are the
spacing distance S, as shown in FIGS. 3 and 8. The minor diameter
W2 of the combined coverage area is slightly larger than the
spacing distance S to account for some degree of overlap. In one
embodiment of the invention, the spacing distance S is between
about two feet and ten feet. In the example of FIG. 9, the spacing
distance S is four feet. In the example where the spacing distance
S is four feet, W2 may be somewhat greater than four feet--perhaps
about five to six feet which is less than 50% of L2.
[0067] The sprinklers 32 of this invention may be installed in an
optional stagger spaced arrangement both along the respective
supply lines 30 and within the structure. The stagger spaced
arrangement is designed to redirect the sprays of water into the
structure with strategically interwoven coverage areas. According
to this arrangement, for each adjacent pair of first and second
supply lines 30 extending parallel to one another, opposing
sprinkler heads 32 are set in an offset relationship relative to
one another. That is, the inwardly facing sprinklers 32 along one
supply line 30 are not pointing directly at, i.e., not in line
with, the inwardly facing sprinklers 32 of the other supply line
30. Said another way, the coverage area 64 from a sprinkler 32 on
one supply line 30 is longitudinally (i.e., along the length of a
supply line 30) offset from the coverage area 64 of an opposing
sprinkler 32 on the next adjacent supply line 30. Thus, a person
standing on the floor 22 in the building and looking up toward the
roof 27 will observe that as between two adjacent supply lines 30
the rightward-pointing sprinklers 32 on the first supply line 30 do
not line up in the L1/L2 directions with the leftward-pointing
sprinklers 32 on the second supply line 30; the heads 32 are in
fact staggered in an alternating fashion. The off-set may be equal
to approximately one-half of the spacing distance S, or "S/2" as
shown in FIG. 8. In the example of FIG. 9, where the spacing
distance S is four feet, the longitudinal offset is about two
feet.
[0068] FIG. 8 shows this stagger spacing arrangement, where the
combined elliptical coverage areas 64 are similar in some respects
to those described in my U.S. Pat. No. 9,381,386 issued Jul. 5,
2016, the entire disclosure of which is hereby incorporated by
reference. However, in this embodiment the inwardly pointing
coverage areas 64 between each adjacent pair of supply lines 30 are
offset to one another. Furthermore, according to the illustrated
example, along one supply line 30 each paired set of sprinklers 32
are longitudinally offset from one another by the same half spacing
S/2 in a regular alternating pattern. In this manner, a design
spacing distance S is calculated or otherwise predetermined to
disperse water over the underlying combined coverage areas 64. The
sprinklers 32 on right side C of the first supply line 30 are
arranged in-between the opposing sprinklers 32 on the second
adjacent supply line 30 (i.e., on the left side B) side so that the
inflows of coverage areas 64 applied between these two supply lines
30 are spaced equally with the half spacing distance (S/2). In this
manner, the coverage areas 64 are interleaved with one another, and
depending on the W2 and L2 dimensions may even overlap one another.
In the example of FIG. 8, the major diameter L2 of each combined
coverage area 64 is optimally distributed into the cove or
valley-like regions between the coverage areas 64 in the two
opposing sprinklers 32 of the adjacent supply line. Thus, the
interlaced coverage areas 64 by two opposing sprinklers 32 achieve
and optimal use of water. However, given that water pressure has a
direct effect on the actual size of the coverage area 64, and
because water pressure will diminish as more fire sprinklers 32 are
activated, it may be desirable to design a generous overlap--on the
order of one to three feet--for a single-activated fire sprinkler
32. It is therefore understood that as water pressure diminishes
due to additional fire sprinklers 32 being activated, the modestly
shrinking coverage area 64 will remain in an ideal geometric
condition with the next adjacent coverage area 64. Therefore, the
degree of overlap needed between adjacent coverage areas 64 may be
calculated for each installation based on line pressure, supply
line 30 sizes and other relevant factors.
[0069] In the example of FIG. 8, the minor diameter W2 of each
coverage area 64 is at least equal to S, and may be between about S
and 2S (i.e., between one- and two-times S). In this example, the
major diameter L2 of each coverage area 64 is greater than half the
distance between adjacent supply lines 30 (e.g., >12.5 feet) so
that at its farthest end the coverage area 64 reaches into the cove
or valley-like space between the coverage areas 64 in the two
opposing sprinkler sets 32 of the adjacent supply line 30. The
large lateral reach in the major diameter L2 direction is benefited
when installed in a structure fitted with open web type beams 24,
such that the supply lines 30 can be located very near to the
ceiling with water sprays easily passing through the open webbings.
It is to be understood that the illustrated examples fully
contemplate extension of these teachings to buildings that have
many bays, with the stagger spacing concepts being repeated between
every two adjacent supply lines 30.
[0070] An advantage of the present invention can be readily
appreciated by comparing FIG. 9, which overlays a typical prior art
sprinkler system with the novel stagger spacing concepts depicted
in FIG. 8. The prior art system is identified by supply lines 66
(drawn as broken lines) carrying traditional pendant style spray
heads 68. The superimposed prior art system shown here may be of
the Early Suppression Fast Response (ESFR) type in which fast
response sprinklers 68 are designed to discharge a high effective
water density in order to combat a fire plume, particularly in high
rack storage applications. In a typical prior art ESFR system, the
supply lines 66 are spaced apart ten feet and the sprinkler heads
68 are spaced apart ten feet. This places the prior art sprinkler
heads 68 in a ten-by-ten foot grid pattern.
[0071] As shown in FIG. 9, a prior art ESFR system requires about
four supply lines 66 to cover the same area as the present
suppression system 20 having only two supply lines 30. The labor
savings represented by a 50% reduction in supply line installation
is significant. Furthermore, as will be validated below, the supply
lines 30 of the present invention can be smaller in diameter than
the prior art ESFR supply lines 66, thus representing a further
cost reduction, as well as a weight reduction which translates to
smaller supporting brackets and possibly smaller purlins or other
structural elements from which the supply lines 30 are hung.
[0072] The prior art spray heads 68 are shown having the typical
circular spray pattern 70 (only one spray pattern 70 shown for
simplicity). If the prior art ESFR is presumed to be supplied with
water at 52 psi, which is a common specification, and the ESFR
spray heads 68 are rated at a 16.8 k-factor, a reasonable
assumption, then the discharge rates from each spray head 68 can be
calculated at about 121 gallons per minute using the formula:
q=k*p.sup.0.5
[0073] Where: q is the flow rate; [0074] k is the nozzle discharge
coefficient; and [0075] p is the line pressure
[0076] Assuming the prior art spray heads 68 are spaced ten feet
apart, each spray head 68 is responsible for about one hundred
square feet of area and the applied water density onto the stored
items 54 per spray head 68 will be in the order of about 1.21
gallons/square foot. In contrast, the system 20 of the present
invention may be fitted, for example, with supply lines 30 that
carry 35 psi water pressure and spray heads 32 having a k-factor of
14. At these specifications, water distribution from each spray
head 32 will be on the order of about 83 gpm. However, if the
coverage areas 64 for the sprinkler heads 32 are defined by W2 at
four feet and L2 at fourteen feet, the applied water density per
spray head 32 onto the stored items 54 will be in the order of
about 1.48 gallons/square foot. In other words, the present
invention contemplates applying more gallons per square foot
through each spray head 32 than is achieved by a typical prior art
ESFR type spray head 68 of a larger k-factor and using higher line
pressures.
[0077] Of course, the critical objective is to arrest growth of a
fire at the earliest possible moment. When the initial sprinkler
head 68 of the prior art activates, only the 1.21 gallons/square
foot is applied. And with spray heads 68 set the typical ten feet
apart, it may take several precious moments for additional spray
heads 68 to activate. In contrast, the spray heads 32 of the
present invention are set at a much closer spacing S, which spacing
is further reduced to S/2 (or other fraction) by the novel stagger
arrangement, so that more sprinkler heads 32 will be activated more
quickly with respective coverage areas being more accurately
distributed toward the fire plume. As a result, more water is
directed at the fire more quickly than prior art systems.
[0078] Heat from a fire plume will initially activate more adjacent
sprinkler heads 32 due to the close and stagger spacing features of
this invention. Because of the directional, non-circular projection
64 of water spray from activated spray heads 32, it is expected
that a majority of discharged water will be directed toward the
fire. As a result, water usage is reduced (compared to the prior
art) and the potential for collateral water damage is similarly
reduced. Importantly also, a maximum discharge of water is directed
at the nascent fire, thereby increasing the likelihood that the
fire will be rapidly suppressed. In comparison with the prior art,
less pressure robbing water is wasted spraying away from the fire
and causing collateral water damage to otherwise unaffected stored
items 54. More water is thus available to apply directly into the
flues 60, 62 with an increased opportunity to control the fire
before it has a chance to spread.
[0079] Benefits of this present invention are many. The blocking
surfaces enable the use of side-discharge type sprinklers (special
application types listed for the given fire scenario) that can be
supplied from any reputable manufacturer, or the unique sprinkler
heads 32 described above. Increased water density can be provided
compared with standard, vertically oriented sprinklers 68. Less
water damage might occur in cases where only one sprinkler 32 is
activated. And the cost of installation is predicted to be less
than that of prior art ESFR systems.
[0080] The claim of increased water density is accomplished by the
ability of this present invention to utilize side-discharge type
sprinklers 32 that have the ability to more accurately distribute
water toward underlying stored items 54. The claim of reduced
installation cost results from the use of one common supply line 30
per bay area (as compared with two supply lines according to prior
art techniques like that taught by U.S. Pat. No. 7,331,399) and
also from the potential to separate supply lines 30 a relatively
large distance apart (e.g., twenty-five feet) due to the long,
narrow and staggered coverage areas of this present invention. In
particular, the non-circular coverage area 64 of each spray head 32
has a major diameter L2 and a smaller minor diameter W2 that
penetrates into the flues 60, 62. The narrow width measure W2
allows spray heads 32 to be stationed closer together along a
common supply line 30, which in turn increases chances that
multiple spray heads 32 will be activated and thereby apply more
water into the flues 60, 62 where a fire plume is growing.
Furthermore, water droplet size and water velocity will be
increased due to the added water pressure and volume, which large
droplet size helps to force more water into the flues 60, 62
against a counter-flow of heat from the fire.
[0081] The staggered, interlaced non-circular coverage areas 64 of
the fire suppression system 20 will discharge water onto the stored
items 54 with a high degree of hydraulic efficiency. Through large
scale fire tests, where fire suppressing systems and fire sprinkler
components are evaluated in a scientific setting, fire control has
been proven to be most effective by maximizing the following system
variables: water discharge velocity, k factor and water droplet
size. Fire control is typically improved by: greater water
velocity, higher k factor and/or larger water droplet size. The
elongated nature of each coverage area 64, where the major diameter
(L2) is significantly greater than the minor diameter (W2),
produces a pattern that more closely mimics a fire hose stream
projected at the fire plume. This, in turn, produces larger water
droplet size and increases water discharge velocity, while
operating at less pressure and volume. Larger water droplets are
beneficial because they are less sensitive to the heat rising
through the flues 60, 62. That is, larger droplets better penetrate
through the flues 60, 62 to reach the fire. Likewise, higher
velocity water spray coupled with greater water density also
penetrates the narrow flues 60, 62 as compared with a slower
moving, lower density water spray as in prior art systems.
[0082] The relatively narrow widths W2 (minor diameters) of the
coverage areas 64 advantageously enables relatively close spacing
(S) of the fire sprinklers 32 along the supply line 30. This close
spacing (S) of heads 32 along the same side of the same supply line
30 provides numerous key benefits, perhaps chief among which is an
improved ability to penetrate the fire flues 60, 62. The unique
opposite-facing design utilizing side-discharge style fire
sprinklers 32 enables a more precise aim directly into the fire
flues 60, 62 thus resulting in a more efficient fire suppression
system with the sprayed water in large quantities going where it is
most needed. Furthermore, the close spacing interval (S) between
sprinkler heads 32 along the same side of the same supply line 30
encourages a condition where more sprinkler heads 32 in the
vicinity of a fire are activated rather than fewer. Multiple
activated spray heads 32 will have a greater chance of avoiding
obstructions and a greater chance of penetrating the fire flues 60,
62 because of the tighter spacing. That is to say, because two or
three spray heads 32 are more likely to be initially activated when
in the past only one spray head is initially activated, any
physical obstructions--like low beams 24, structural columns,
equipment or atypically large objects--will not be as likely to
block the initial water spray in cases whether the obstruction is
between one spray head 32 and the fire. Not to mention, greater
distance between adjacent supply lines 30 improves the probability
that each supply line 30 can be placed in its own bay between
adjacent beams 24 as shown in FIGS. 3 and 4 where they will not be
as susceptible to blockage by low-hanging beams 24.
[0083] Furthermore, multiple activated spray heads 32 that
discharge long, narrow streams of water like a firehose will better
attack a fire in the deep interior regions of stacked stored items
54 via the only direct avenues--the flues 60, 62. Even using spray
heads 32 with a smaller k-factor fed by lower line pressure, it was
shown (above) that larger water distributions (gallons/sq. foot)
are possible because the coverage areas 64 are smaller by
comparison to prior art ESFR systems. The long, narrow coverage
areas 64 are not only accurately aimed toward a fire, but also
naturally produce larger water droplets via the design of the
deflector which effectively produces an outflow like a jet stream.
As a result, water is delivered in a greater density into the flues
60, 62, where it is most-needed. This hose stream effect also works
as a fire stop because the water and the droplet sizes are denser.
This invention, which may be understood as subscribing to a "spot
density theory," goes against the way conventional heads 68 are
built, which is on the basis of density (volume/area). Those of
skill in the art will acknowledge that there are many shortcomings
of the prior art paradigms which place a high premium on
density--that is, on blanketing the entire footprint of the storage
area with a balanced density of water. In contrast, the spot
density theory advanced here allows an early onset fire to be
quickly blocked from growing by the targeted coverage area(s) 64
produced by one or more activated spray heads 32 of this invention.
Accordingly, early stage fire suppression success rates will
increase based on the principles of this invention.
[0084] FIG. 10 describes an alternative embodiment wherein the
supply line 30 is composed of multiple short sections joined
end-to-end by couplings 72. The couplings 72 may be any
commercially available type, such as the grooved pipe joining
technology marketed by the Victaulic Company of Easton, Pa. to name
but one possible source. Alluding back to FIG. 4, where by phantom
lines it was described that a sprinkler 32 may be skewed relative
to horizontal as an alternative to adjusting its deflector in order
to achieve a desire placement of the coverage area 64, FIG. 10
represents a method by which adjustment can be accomplished after
placement of the sprinkler 32 and without altering its deflectors.
In the Applicant's U.S. Pat. No. 9,381,386, attention is given to
the concept of configuring and arranging the coverage areas 64
relative to the overall height and location of the stored items 54
so that, at all stages of a fire but particularly at the initial
stages, a maximum amount of water is applied to the flues 60, 62
laying directly above the fire so that very little spray is wasted
dousing nearby (non-burning) stored items. For all of the reasons
therein described, it is desirable to install the present fire
suppression system 20 so that the coverage areas 62 are matched to
the height and location of the nearby stored items 54. However,
over time the owner of a storage space is likely to change the
height and/or location of the stored items 54, such that the
alignment of coverage areas 64 becomes outdated. By loosening the
couplings 72 at each end of a section of supply line 30, the supply
line 30 can be rotated and with it the sprinkler head 32 carried
thereon. By careful attention, the coverage area 64 of each spray
head 32 can be adjusted whenever there is a change in the height
and/or location of the stored items 54 in order to achieve the
benefits and objectives explained in U.S. Pat. No. 9,381,386. In
another contemplated variation, the saddles 34 may be
custom-attached to the supply line 30 at fixed downwardly-skewed
angles to achieve an aimed but non-adjustable configuration similar
to that depicted in FIG. 10. That is to say, a pre-determined
coverage area 64 can be accomplished by setting the saddles 34 at
the desired angles at the time of fabrication, thereby achieving
skewed spray head positioning without use of couplings 72.
[0085] Referring now to FIGS. 11-22, an alternative embodiment of
the fire suppression system is described in which the sprinkler
system is composed of a series of three-head arrays 100. Each
three-head array 100 comprises a repeating group, or cluster, of
three consecutive sprinklers placed at regularly-spaced intervals
along the length of the supply line 108. The arrays, or clusters,
are generally identical, and form a recurring pattern along the
length of the supply line 108. So, as an example, if the supply
line 108 is forty-feet long and each three-head array 100 occupies
four feet of length, the supply line 108 will support approximately
ten three-head arrays 100. Of course, the length of a three-head
array 100 can be longer (or shorter) than the suggested four feet.
Each three-head array 100 comprises a vertical-discharge sprinkler
102 and two side-discharge sprinklers 106. The combination of
vertical 102 and side 106 discharge sprinklers has significant
advantages, as will be described. Water from the vertical-discharge
sprinkler 102 has the ability to penetrate a fire plume that is
located directly under the supply line 108 faster than will the
water from either side-discharge sprinkler 106, and also produces a
beneficial chilling effect that helps control the premature
triggering of adjacent sprinkler heads. Therefore, when a fire is
directly below (or nearly directly below) the supply line 108,
water from the vertical-discharge sprinkler(s) 102 can quickly wet
the relevant coverage area, which may be helpful to retard the
spread of the fire.
[0086] FIGS. 11-13D depict one exemplary three-head array 100 for
the fire suppression system 100. In this example, the
vertical-discharge sprinkler 102 is of the pendant-type directly
coupled with the supply line 108, and oriented vertically pointing
down. It is contemplated that the vertical-discharge sprinkler 102
could instead be oriented vertically pointing up as shown in FIG.
30, which in certain applications may be preferred to the
downward-pointing orientation shown in FIG. 11. The
vertical-discharge sprinkler 102 includes a heat collector 104, in
the form of a bell-shaped shroud. The heat collector 104 provides
several benefits. As the name implies, the heat collector 104 helps
concentrate heat rising and/or radiating from a fire to provide
early activation for a trigger (or fuse) 109 of the
vertical-discharge sprinkler 102. The heat collector 104 also acts
as a blocking surface, or shield, against cold-soldering from the
water spray 110 of adjacent spray heads that may have been earlier
activated. The heat collector 104 also facilitates, to a degree,
directional control of the water 110 discharge pattern produced by
the vertical-discharge sprinkler 102. One exemplary embodiment of
the heat collector 104 is made by forming a non-flammable material,
such as metal, into a circular frusto-conical shape. The size and
shape of the heat collector 104 can be varied depending on the
preferred coverage shape and size of the discharge pattern. In
another example, the heat collector 104 could be parabolic, with
the trigger 109 being generally located at the parabolic focal
point like a radio signal antenna. Or the heat collector 104 could
be modeled in the spirit of a Fresnel reflector, with multiple
internal facets each reflecting radiant heat toward the trigger
109. Naturally, many alternative configurations are possible.
[0087] A bottom view of the vertical-discharge sprinkler 102 is
depicted in FIG. 12. Although shown in FIGS. 11-12 as a
smooth-sheet-like conical member, the heat collector 104 may be
specially configured to accentuate its heat collecting properties
and/or its discharge pattern shaping properties. For one example,
the heat collector 104 may be designed with a thermal pin (or fin)
structure that enhances the trigger activation time by channeling
the collected heat toward the trigger/fuse 109. Or the heat
collector 104 could be designed with reflecting surfaces that
intensify the radiant heat directed at the trigger/fuse element
109. Other variations are also certainly possible to accelerate
trigger 109 response time via enhanced conduction, convection
and/or radiant heat transfer in the event of a fire.
[0088] The vertical-discharge sprinkler 102 is shown in FIGS. 11-12
fitted with a trigger 109 in the form of a fusible link. Naturally,
any suitable type of trigger 109 can be used. Notably absent from
the vertical-discharge sprinkler 102 is any form of in-stream
deflector feature to spread the discharge water 110 as in
conventional pendant spray heads. While it is possible to
incorporate a more traditional in-stream deflector feature (as in
the embodiment of FIG. 21), the vertical-discharge sprinkler 102
may be configured to provide a directional discharge pattern
controlled chiefly by the shape of its discharge orifice and by the
heat collector 104. In this manner, a relatively large, dense
concentration of water 110 can be sprayed over a fairly defined
coverage area directly below the supply line 108.
[0089] In appropriate applications, the response time to activate
the trigger 109 can be pre-determined by selecting a fusible link
109 for the vertical-discharge sprinkler 102 that has a higher or
lower activation temperature that the respective triggers of the
side-discharge sprinklers 106. In one configuration, graphically
illustrated in FIG. 14, the trigger temperature of the
vertical-discharge sprinkler 102 can be configured to be lower than
that of the two side-discharge sprinklers 106 so that the
vertical-discharge sprinkler 102 will activate earlier than the two
side-discharge sprinklers 106. That is to say, the
temperature-sensitive trigger for each side-discharge fire
sprinkler 106 is configured to activate at a predetermined
temperature T.sub.h, and the temperature-sensitive trigger 109 for
the vertical-discharge fire sprinkler 102 is configured to activate
at a predetermined temperature T.sub.v which is lower than the
predetermined temperature T.sub.h of the side-discharge fire
sprinklers 106. This configuration enables a quickly concentrated
discharge of water 110 to be initially sprayed below the supply
line 108 by the vertical-discharge sprinkler 102. Because only one
vertical-discharge sprinkler 102 is flowing in this scenario,
maximum water pressure and water flow is sprayed downwardly onto
the fire. As a result, it is possible that the fire could be
preemptively suppressed by just the vertical-discharge sprinkler
102. I.e., without triggering either of the side-discharge
sprinklers 106. By delaying activation of one or both
side-discharge sprinklers 106 in this scenario, the water flow and
pressure that the side-discharge sprinklers 106 would otherwise
consume is conserved for the benefit of the one activated
vertical-discharge sprinkler 102. Depending on the desired water
coverage areas, the temperature of the fusible link 109 can be
determined by test or simulation.
[0090] Continuing still in the example of FIGS. 11-12, the
three-head array 100 includes two side-discharge sprinkler heads
106 arranged directly back-to-back. Each side-discharge sprinkler
head 106 may be substantially identical to those described above in
connection with FIGS. 2-10 with one exception: the down wash
section 46 may be omitted or modified. In this embodiment, the
vertical-discharge sprinkler 102 obviates the need to divert some
or all water 110 directly below and behind the supply line 108,
which was a primary purpose of the down wash section 46. As with
the vertical-discharge sprinkler 102, both side-discharge
sprinklers 106 may be fitted with a fusible link type trigger.
However, any suitable type of trigger can be used in the
alternative. A baffle (like the baffle 44 in FIG. 5) may optionally
be included inside the nozzle-like hood of each side-discharge
sprinkler 106 to create a desired discharge pattern.
[0091] FIG. 13A is a schematic drawing showing the three-head array
fire suppression system 100 in operation in a structure whose roof
27 is supported by widely-spaced I-beams 24 like those commonly
found in large storage warehouse facilities. FIG. 13A, which is
similar in some respects to FIG. 6, depicts a ground fire located
to one side (i.e., the right side) of the supply line 108. The
deflectors of the right-side discharge sprinkler 106 and the
vertical-discharge sprinkler 102 help concentrate the arising heat
so as to readily activate only those two sprinklers while the left
side-discharge sprinkler 106 remains un-activated. As described
above in connection with FIG. 6, this situation allows a
concentrated discharge of water 110 onto the fire with minimal
collateral damage or unnecessary water/pressure consumption via the
un-activated left side-discharge sprinkler 106. FIG. 13A
illustrates the manner in which the water 110 discharged from the
right side-discharge sprinkler 106 is reflected on the heat
collector 104 like an umbrella. As a result, the heat collector 104
prevents the water 110 from contacting the trigger 109 in the
vertical-discharge sprinkler 102 to minimize the chances of
undesirable "cold soldering" in the event the right side-discharge
sprinkler 106 were to activate before the vertical-discharge
sprinkler 102.
[0092] FIG. 13B shows a three-head array fire suppression system
100 in operation in a structure having a roof 27 that is supported
by narrowly-spaced beams 24, in the form of rafters or trusses,
like those commonly found in attics, sheds, barns and other types
of smaller storage facilities. Attic-type applications like this
are considered especially high-challenge because the beams 24 and
roof 27 are frequently made of wood products. The combustible
nature of these structural members adds to the density of
combustible items stored in the attic space. As in FIG. 13A, a
ground fire is located on the right side of the supply line 108.
Water forcefully discharged in narrow-banded streams from one
right-side discharge sprinkler 106 and one vertical-discharge
sprinkler 102 douse the fire with heavy flows of liquid water. The
concentrated discharge of water onto the fire helps to minimize
collateral damage while economizing water/pressure consumption. The
high-mounted location of the sprinkler array 110, i.e., in close
proximity to the roof peak 28, enables the hose stream effect
produced by the right and left side-discharge fire sprinklers 106
to wet a greater portion of the exposed combustible framing members
24 and/or combustible roof decking 27 using high-velocity water. It
should be noted that the nearer the sprinkler array 100 is to the
peak 28, the shallower the angle of incidence between emitted water
stream and roof decking 27. A shallower angle of incidence means
less deflection of the water stream and thus more surface area that
can be wetted. Furthermore, location of the sprinkler array 110
close to the peak 28 where heat naturally collects will improve
response times. Thus, in high-challenge applications that are
further complicated by combustible framing members 24 and/or
combustible roof decking 27, as in pitched-roof attics, the present
invention is better suited to retard growth of a fire. Furthermore,
the high-velocity wetting effect can, if desired, be designed to
use nearby structural features like a pitched roof as a secondary
deflector to enable highly-customized water distribution
options.
[0093] FIG. 13C shows the three-head array 100 of FIG. 13B in a
highly-simplified attic installation. In this view, various
placement options for the supply line 108 and array 100 relative to
the roof peak are illustrated. In combination with adjustable
side-discharge deflectors 106, the trajectory of the high-velocity
water stream can be aimed to suit the roof pitch and/or accommodate
other environmental factors. By locating sprinkler heads capable of
emitting a high-velocity water stream in the uppermost peak 28 of a
roof 27, many advantages can be realized. For one, the sprinklers
102, 106 can be located very near to where heat naturally collects
in the event of a fire. As a result, faster response times for the
heat-sensitive triggers are possible. Conversely, if obstructions
or other factors make placement near the ridge 28 impractical,
lower positions can be accommodated as depicted through the phantom
line alternatives. Another advantage of placing the array 100 very
near to the peak 28 is that more of the inner roof 27 surface will
be wetted. In embodiments where the side-discharge sprinklers 106
are made adjustable, as illustrated in FIG. 13D, a still further
advantage is that the side-discharge water streams can be angled
for maximum effect. For example, it may be desirable to utilize the
inside surface of the roof 27 as a secondary deflector. This is
possible by adjusting the deflectors of the side-discharge
sprinklers 106. Adjustment of the side-discharge sprinklers 106 can
be accomplished by any number of methods. FIGS. 4 and 10 illustrate
two different methods. Alternatively, the deflector hoods 42 can be
plastically deformed or bent to achieve the desired angle. Or the
deflector hoods 42 can be configured with an articulated joint to
allow angular adjustment. Naturally, there are many methods by
which adjustment of the deflectors can be accomplished after
placement of the sprinkler 32 has been installed.
[0094] FIGS. 13A-D are thus intended as representative
illustrations to show the broad range of applications possible for
the teachings and principles of this invention. Indeed, the
concepts of this invention are applicable to many types of
applications, the most attractive of which are expected to be the
various forms of high-challenge storage applications.
[0095] FIG. 14 is a simplified Temperature-Time graph illustrating
the responsiveness for one exemplary embodiment of the three-head
array fire suppression system 100 shown in any of FIGS. 13A-D. This
graphic illustrates the optional configuration in which trigger
temperature (T.sub.v) for the trigger 109 of the vertical-discharge
sprinkler 102 is lower than the trigger temperature (T.sub.h) for
either of the side-discharge sprinklers 106. As a result, the
vertical-discharge sprinkler 102 is designed to activate at time
ti, whereas one or both side-discharge sprinklers 106 will not
activate until the later time t.sub.2. In the time span between
t.sub.1 and t.sub.2, only the vertical-discharge sprinkler 102 is
actively spraying water 110 onto the fire below, thus concentrating
the water discharge for a period of time before additional
side-discharge sprinklers 106 are activated (at T.sub.h, t.sub.2).
If the vertical-discharge sprinkler 102 is successful during the
time span to suppress the fire, there is a possibility that water
damage to collateral objects and property can be avoided. Water
spray from the vertical-discharge sprinkler 102 will create cooling
effect that will keep the nearby side-discharge sprinklers 106 from
firing too soon.
[0096] FIG. 15 corresponds generally to FIG. 8 and demonstrates a
variation in which the side-discharge sprinklers 106 are
stagger-spaced along the supply line 108. The vertical-discharge
sprinklers 102 in this example are installed directly below every
other side-discharge sprinkler 106. In this configuration, the
coverage areas 112 from the vertical-discharge sprinklers 102 fill
below the respective supply lines 108 and in-between the elliptical
coverage areas from the side-discharge sprinklers 106. Of course,
the size and distribution of the pendant coverage areas 112 can be
modified to suit the application. The long, narrow reach of the
side-discharge sprinklers 106 is designed to reach forcefully into
the flues 60, 62 (FIG. 7) in much the same way as the directed
discharge from a hand-held fire hose might penetrate into the
interior regions of stored items 54 stacked in storage racks 56
where the locus of a fire typically occurs. The vertical-discharge
sprinklers 102, on the other hand, produce a predominantly downward
(vertical) spray pattern which, when triggered before the adjacent
side-discharge sprinkler heads 106, creates the aforementioned
cooling effect with beneficial results.
[0097] FIG. 16 is a view similar to FIG. 15, but where the two
side-discharge sprinklers 106 in each array 100 are arranged
directly opposite one another along the supply line 108. In this
example, the vertical-discharge sprinkler 102 is positioned
half-way toward the next adjacent group of side-discharge
sprinklers 106 in the adjacent array 100. As in FIG. 15, the
coverage areas 112 fill the otherwise un-covered pockets below the
supply line 108. And as described above in connection with FIG. 8,
the staggering of opposing side-discharge sprinkler heads 106 on
adjacent parallel supply lines produces the interlaced non-circular
coverage areas 64 that discharge water with a superior hydraulic
efficiency. Of course, other configurations are possible in which
the three sprinklers heads 102, 106 in each array are arranged
along the supply line 108.
[0098] FIG. 17 is another view similar to FIGS. 15 and 16, but
where all side-discharge sprinklers 106 and the vertical-discharge
sprinklers 102 are axially offset from one another along the supply
line 108. In this fully stagger spaced array 100, the coverage area
for each three-head array 100 is subdivided corresponding to
targeted areas. As a result, the number of discharge sprinklers
102, 106 can optimized to suppress the fire, and water pressure in
the supply line 108 can be maintained even when using a smaller
pipe diameter for the supply line 108. The smaller pipe size,
eventually, can reduce the labor costs and pipe material costs so
that the price of the fire suppression system will be decreased.
Additionally, the fully stagger spaced array 100 of FIG. 17 may
have manufacturing/assembly advantages, especially when using a
smaller diameter supply line 108.
[0099] FIGS. 18-20 depict yet another alternative embodiment in
which a vertical discharges sprinkler 114 is configured to
discharge water at two different k-factors: k-factor (A) and
k-factor (B). As mentioned above, the k-factor represents a nozzle
discharge coefficient. Each vertical-discharge fire sprinkler 114
connects to the supply line 108 through a nipple (see #36 in FIGS.
4 and 5). A flow divider may be located inside the nipple to
segregate the outflow of liquid water into at least two unequal
streams, one of the streams characterized by first nozzle discharge
coefficient (k-factor A) and the other stream characterized a
second nozzle discharge coefficient (k-factor B) of unequal
magnitude to the first nozzle discharge coefficient (k-factor A).
See cross-sectional view of FIG. 18. In this embodiment, k-factor
(A) is smaller than k-factor (B) so that a somewhat egg-shaped
coverage area 118 can be produced, as shown in FIG. 20. The
three-head array fire suppression system 100 with the pendant-type
sprinkler 114 can, in some applications, optimize the water usage
by strategically distributing the coverage areas 118.
[0100] A bottom view of the pendant-type sprinkler 114 is shown in
FIG. 18. Notable in this example is an optional non-circular heat
collector 116. This demonstrates the aforementioned possibility of
altering the shape of the heat collector 116 to control the shape
of the coverage area 118 and/or to maximize heat
collecting/concentrating characteristics and/or to optimize
blocking characteristics in the event of cold-soldering
concerns.
[0101] Another alternative 120 of a pendant-type sprinkler is shown
in FIG. 21. In this view, the pendant sprinkler 120 has a
traditional frame structure with an in-stream diffuser 122. Its
trigger 124 is in the form of a heat-sensitive glass bulb. This
demonstrates the possibility of altering the type of sprinkler
head--in not only the pendant but also in the side discharge
heads--so that off-the-shelf types can be used, if desired.
[0102] The three-head array 100 can be installed any place in a
warehouse or attic or shed or other area to be protected so as to
optimize the fire suppression capabilities. FIG. 22, which
corresponds generally to FIG. 7 as described in detail above,
illustrates yet another alternative configuration in which the fire
sprinkler system is located in one of the flues (e.g., longitudinal
flue 134) in a storage rack 126. In this configuration, the supply
line 108 is aligned between stored items 128, and the
side-discharge sprinklers 106 and the pendent-type sprinkler 102
are arranged between the gap of the stored items 128. The
three-head array system on the top level of shelves 130 can
effectively intercept a transverse flue 132 or a longitudinal flue
134 formed in the gap of the palletized stored items 128 by
discharging a maximum amount of water directly into the flues 132,
134. Naturally, the supply line 108 can be placed any level of the
shelves 130 to optimize the fire suppression, and the space between
the sprinklers 102, 106 can adjusted to coincide with transverse
flues 132, i.e., the regularly-spaced gaps between the stacks of
palletized stored items 128. Naturally, the in-rack option depicted
in FIG. 22 may be arranged so that the side discharge sprinklers
106 will spray into adjacent racking by missing any structural
members in the flue spaces 132, 134.
[0103] The embodiment of FIG. 22 can be understood as but another
variation on the earlier embodiments, e.g., FIGS. 13A-C, in that
the flues correspond to the aforementioned bays between adjacent
beams 24. An advantage of this invention is the ability to
strategically locate sprinklers 102 and/or 106 into the spaces
where fires are most likely to start. Once activated, the
sprinklers 102 and/or 106 will discharge forceful jet streams of
liquid water into the vicinity of the fire to quickly extinguish
the threat with minimized collateral damage. This present invention
enables the advantageous combination of multiple orientations of
fire sprinklers, thus combining the respective strengths of each to
improve fire protection while at the same time saving both material
and labor. Furthermore, the novel combining of multiple
orientations of fire sprinklers eliminates certain weaknesses
inherent in each orientation by itself. As a result, the fire
suppression system and method harness the working power of working
of multiple orientations of fire sprinklers to produce, in effect,
a super fire sprinkler system and method.
[0104] Turning now to FIGS. 23-28, yet another alternative fire
suppression system is shown including optional lateral heat shields
140. The lateral heat shields 140 enable quicker response times for
side-discharge sprinklers 106 facing toward a fire, while delaying
the response times for side-discharge sprinklers 106 facing away
from a fire. That is to say, the lateral heat shields 140 are
passive devices that prevent early discharge from the
side-discharge sprinklers 106 pointing away from a fire. As a
direct result, water flow/pressure is conserved for the
side-discharge sprinklers 106 pointing in the direction of a fire
as well as affected vertical pendant sprinklers 102 (or 114,
120).
[0105] The lateral heat shield 140 can take many different forms.
In FIGS. 23 and 24, a lateral heat shield 140 is shown in one
exemplary configuration having a boxy, flower-like construction
somewhat reminiscent of a reflector-style radio antenna. Although a
parabolic shape might perhaps be preferred, considerations of
manufacturing cost and installation ease tend to favor a simple
design. It is contemplated that each lateral heat shield 140 will
have a heat-concentrating side 142 (FIG. 23) and a heat-scattering
side 144 (FIG. 24). The heat-concentrating side 142 is generally
concave, whereas the heat-scattering side 144 is generally convex.
The terms concave and convex are used here generally to include a
wide variety of shapes, including but not limited to smooth curves
and multi-faceted segments, that generally resemble the inside and
outside surfaces of a bowl or at least a portion thereof. Both
sides 142, 144 are manufactured from suitable material(s) to
efficiently reflect radiant heat from a fire. Furthermore, the
lateral heat shield 140 should be capable of maintaining its shape
at high temperature, and therefore sheet metal compositions (like
stainless steel to name one) may be considered better candidates
than plastic materials. Of course, any material that provides
satisfactory heat reflectivity and temperature resistance could be
considered. For example, if cost factors were sufficiently
compelling, the lateral heat shields 140 could be made from a
high-temperature plastic material coated or clad or impregnated
with a reflective substance to achieve the desired radiant heat
reflection qualities. Naturally, many material choices are
possible.
[0106] FIG. 25 is a cross-section through a three-head array 100
like that described above in connection with FIGS. 11-22. From this
perspective, it can be seen that each lateral heat shield 140 is
operatively disposed between a respective right or left
side-discharge fire sprinkler 106 and the supply line 108 so that
its heat-scattering side 144 faces toward the supply line 108. That
is to say, each lateral heat shield 140 is associated with one
side-discharge fire sprinkler 106, and is oriented so that its
heat-concentrating side 142 faces away from the supply line
108.
[0107] Attachment of the lateral heat shield 140 is accomplished by
a connector, that may take many different ways. In one possible
configuration, the connector is a clamp or spring clip (not shown)
that functions to directly attach the lateral heat shield 140 to
the supply line 108. In another possible configuration, the
connector is attached directly to, or otherwise integrated with,
the hood 42 of the side-discharge sprinkler 106. However, in the
illustrated examples, the connector at least partially surrounds
and attaches directly to the respective saddle 34 emanating from
the supply line 108 via a collar 146. In this exemplary embodiment,
the collar 146 extends axially from a backplate 148 portion of the
lateral heat shield 140. The backplate 148 includes an aperture
therein that aligns with the collar to receive the saddle 34, after
which the side-discharge fire sprinkler 106 is threaded into
position. To securely hold the heat shield 140 in place, the collar
146 may include some form of slack take-up device. In the
accompanying illustrations, the slack take-up device is shown in
the form of set screws 150 threaded through the collar 146 so that
their tips press against the saddle 34. However, a slack take-up
device could take many other different configurations, including
but not limited to resilient self-gripping elements, constricting
clamps, jam-nuts, and the like. That is to say, the slack take-up
device is not intended to be limited to the set screw 150
configurations shown in the Figures.
[0108] Turning again to the shape of the lateral heat shields 140,
it bears repeating that many different designs are possible. The
boxy flower-like construction shown in the figures is exemplary
only but nevertheless merits description. Considering still FIGS.
23-25, the backplate 148 is shown to be of a generally flat
construction, however contoured shapes (e.g., parabolic) are
possible. Furthermore, the flat backplate 148 is shown having a
generally rectangular shape, however other polygonal, curved and
mixed curved/straight shapes are possible. A plurality of pedals
152 radiate from the backplate 148--one pedal 148 from each of the
four linear edges of the backplate 148. Each pedal 152 is shown as
a very simple rectangular shape, but of course other shapes are
certainly possible. The Figures also show constructions in which
pedals 152 entirely surround the backplate 148. However, in some
contemplated embodiments one or more edges of the backplate 148 may
be unencumbered with pedals 148. For example, it some applications
it may be desirable to omit a pedal 152 along the bottom edge of
the backplate 148 to better collect heat energy when a fire is
relatively close to the supply line 108.
[0109] Because each pedal 152 adjoins the backplate 148 along a
generally linear interface, the angle of each pedal 152 could be
manipulated as suggested by the phantom lines in FIG. 25 to achieve
optimal reflectivity and/or water spray shielding. It is not
mandatory that any of the pedals 152 be adjustable, nor indeed that
all of the pedals 152 be adjustable. In some contemplated
variations, only one or some of the pedals 152 are arcuately
adjustable relative to the backplate 148 along the generally linear
interface, while the remaining pedal(s) 148 are non-adjustable.
Many possibilities exist to achieve optimal results.
[0110] The lateral heat shield 140 technology is applicable in
two-head array settings like those described in connection with
FIGS. 3-10, as well as three-head array 100 applications like those
associated with FIGS. 11-22. In three-head array 100 settings, the
lateral heat shield 140 offers some additional advantages. In
particular, unlike the previous three-head array 100 examples which
required use of a heat collector 104 with the vertical discharge
sprinkler 102, in the example of FIG. 25 it is possible (but not
mandatory) to omit the heat collector 104 in cases whether all
three sprinkler heads in the three-head array 100 are axially
aligned. That is to say, when the side discharge sprinklers 106 are
directly back-to-back and the vertical discharge sprinkler 102 is
also aligned as in FIG. 25, the pedals 152 that extend downwardly
from the backplate 148 may be configured to sufficiently protect
the trigger of the vertical discharge sprinkler 102 against cold
soldering. The lower edge 154 of the downwardly extending pedal 152
may be designed to at least partially vertically cover the
temperature-sensitive trigger 124 (or fuse) of the
vertical-discharge fire sprinkler 102, in which case the heat
collector 104 may (optionally) be omitted as shown in FIG. 25.
However, if all three sprinkler heads in the three-head array 100
are not axially aligned, then it is likely that the heat collector
104 will be required to protect the temperature-sensitive trigger
124 (or fuse) of the vertical-discharge fire sprinkler 102 against
cold-soldering. (See FIG. 27.) And indeed, even if all three
sprinkler heads in the array 100 are aligned, it may still be
advantageous to include a heat collector 104 for the
heat-collecting benefits.
[0111] FIG. 26 is a schematic depiction of the lateral heat shields
140 in operation with respect to a three-head array 100. In this
illustration, a fire has emerged at a location spaced laterally
from the supply line 108. Radiant heat energy from the fire
interacts with the fire sprinkler system. Heat reaches the vertical
discharge sprinkler 102 without disruption or interference by the
lateral heat shields 140. For the right side-discharge sprinkler
106 closest to the fire, the radiant heat energy encounters the
heat-concentrating side 142 of its lateral heat shield 140. The
interior surfaces of the pedals 152 and the backplate 148 reflect
the radiant heat in a converging manner toward the vicinity of the
trigger element in the right side-discharge sprinkler 106 closest
to the fire. This concentration of heat provokes the right
side-discharge sprinkler 106 to activate quickly in the event of a
fire. And, as mentioned, the response time of the vertical
discharge sprinkler 102 will proceed in the normal manner. However,
for the left side-discharge sprinkler 106 pointed away from the
fire, the radiant heat energy will encounter the heat-scatter side
142 of its lateral heat shield 140. The exterior surfaces of the
pedals 152 and backplate 148 will reflect the radiant heat in a
diverging manner away of the trigger element in the left
side-discharge sprinkler 106. This dispersion of heat retards
activation of the left side-discharge sprinkler 106, whose water
spray would be of little-to-no value given the location of the
fire.
[0112] FIG. 27 is a view as in FIG. 25 but showing the left and
right side-discharge sprinklers 106 axially offset from one
another. The vertical discharge sprinkler 102 in this case is
fitted with a heat collector 104 to protect against
cold-soldering.
[0113] FIG. 28 is yet another alternative embodiment demonstrating
further contemplated variations. In this example, the pedals 152'
of each lateral heat shield 140' are fused to more efficiently
reflect radiant heat from a fire. Although the pedals 152' appear
here as multi-faceted dishes, it will be understood that many
variations are possible, including smoothly curving frusto-conical
bells similar to the heat collectors 140' as well as almost any
imaginable asymmetrical structure having suitable concave and
convex features.
[0114] Another notable feature of the FIG. 28 embodiment is the
downwardly angled side-discharge sprinklers 106'. The saddles
associated with the side-discharge sprinklers 106' have been
attached to the supply line 108' at skewed angels to achieve a
desired coverage area for a similar purpose to that of the
embodiment of FIG. 10. Of course, the angularly adjustable design
of the FIG. 10 embodiment could also be implemented with any of the
lateral heat shield 140, 140' embodiments to enable in-the-field
setting of coverage areas.
[0115] FIG. 29 shows another alternative embodiment in which the
pedals 152'' of each lateral heat shield 140'' are shaped to
facilitate controlled back-spray in combination with the
aforementioned heat reflection properties. In this view, the
sprinkler 106'' includes a downwash deflector 46'' like that
described above in connection with FIGS. 3-10 to exemplify
applications in which there is intentional rearward distribution of
the sprayed water. This figure demonstrates the adaptability of the
lateral heat shield 140'' to two-head arrays, as well as three-head
arrays, when additional downwash and/or overlap in the coverage
area below the supply line 108'' is desired. The lower edge 154''
of the pedals 152'' is shown back-swept to help evenly distribute
sprayed water below the supply line 108''. The back-sweep of the
lower edge is also suggested in phantom in FIG. 25 and can likewise
be used to shield a pendent sprinkler (not shown) from
cold-soldering spray. As with most features of this invention, the
shapes of the lateral heat shield 140'' and the downwash deflector
46'' be modified to achieve a well-defined coverage area with the
desired water density distribution characteristics, and without
sacrificing the many benefits afforded by the lateral heat shield
technology.
[0116] The lateral heat shields 140 of FIGS. 23-29 have numerous
benefits. Perhaps foremost, the lateral heat shields 140 allow
better control of the side-discharge sprinklers 106 needed to fight
a laterally-offset fire, because the limited water supply is less
likely to be shared with the side-discharge sprinkler 106 that is
pointing away from the fire. The water pressure required to
adequately fight the fire will be maximized in the direction of the
fire because the system will not be taxed by unwanted discharging
heads pointing in unproductive directions. Also, use of lateral
heat shields 140 allows more economical pipe sizing. This is a
subtle but compelling fact that saves both labor and material
costs. With reductions in labor and material costs, competition in
the marketplace will be enhanced because smaller installer
operations we be able to bid for large jobs that would otherwise
require too much working capital. Furthermore, because water
pressure will be maximized in the direction of the fire, the
activated sprinkler heads will produce greater water travel
distances and greater water velocity for extinguishment. That is,
the coverage area of the activated spray heads will be larger and
more effective because the system will not be taxed by unwanted
discharging heads. Thus, the system hydraulics will be improved
because the lateral heat shields 140 enable better discharge
control. When lateral heat shields 140 are combined with a
multi-head sprinkler array (both two-head and three-head
configurations), the best of fire sprinkler principles can be
achieved, yielding a fire sprinkler system capable of delivering
more control of sensitivity.
[0117] The foregoing invention has been described in accordance
with the relevant legal standards, thus the description is
exemplary rather than limiting in nature. Variations and
modifications to the disclosed embodiment may become apparent to
those skilled in the art and fall within the scope of the
invention. For example, the lateral heat shields 140 of FIGS. 23-28
and/or the angular adjustability configurations of FIG. 10 could be
integrated into any of the embodiments described in FIGS. 11-22,
and vise-versa. Furthermore, particular features of one embodiment
can replace corresponding features in another embodiment or can
supplement other embodiments unless otherwise indicated by the
drawings or this specification.
* * * * *