U.S. patent application number 14/580323 was filed with the patent office on 2015-04-23 for apparatus and method for conducting hot work.
The applicant listed for this patent is Safezone Safety Systems, LLC. Invention is credited to David Allen Dore, Chad A. Grand, Robert C. Tucker.
Application Number | 20150111161 14/580323 |
Document ID | / |
Family ID | 52395665 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150111161 |
Kind Code |
A1 |
Dore; David Allen ; et
al. |
April 23, 2015 |
Apparatus and Method for Conducting Hot Work
Abstract
In the specification and drawings, an apparatus for conducting
hot work is described and shown with an enclosure; a hot work
apparatus operable within the enclosure; and a detector located
exterior of the enclosure, the detector being in detecting
communication with the interior of the enclosure, such that the
detector detects the presence of a condition within the enclosure.
A method of conducting hot work is also described and shown.
Inventors: |
Dore; David Allen; (Erath,
LA) ; Tucker; Robert C.; (Baton Rouge, LA) ;
Grand; Chad A.; (Baton Rouge, LA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Safezone Safety Systems, LLC |
Houma |
LA |
US |
|
|
Family ID: |
52395665 |
Appl. No.: |
14/580323 |
Filed: |
December 23, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12412197 |
Mar 26, 2009 |
8947249 |
|
|
14580323 |
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Current U.S.
Class: |
432/1 ;
432/32 |
Current CPC
Class: |
F27D 21/04 20130101;
B23K 37/006 20130101; G01N 33/0057 20130101; G05B 9/05
20130101 |
Class at
Publication: |
432/1 ;
432/32 |
International
Class: |
F27D 21/04 20060101
F27D021/04 |
Claims
1. An apparatus for conducting hot work comprising: a. an
enclosure; b. a hot work apparatus operable within said enclosure;
and c. a detector located exterior of said enclosure, said detector
being in detecting communication with an interior of said
enclosure, such that said detector detects the presence of a
condition within said enclosure.
2. The apparatus of claim 1 wherein said hot work apparatus is shut
down in response to said detector detecting the presence of a
predetermined condition within said enclosure.
3. The apparatus of claim 1 further comprising a housing located
adjacent to said enclosure, the interior of said housing being
fluidly connected to the interior of said enclosure, said detector
being fluidly connected to the interior of said housing.
4. The apparatus of claim 3 further comprising a gap between said
housing and said enclosure.
5. The apparatus of claim 3 wherein said housing is not in contact
with said enclosure.
6. The apparatus of claim 3 wherein said housing is portable.
7. The apparatus of claim 3 further comprising a stand attached to
said housing.
8. The apparatus of claim 3 further comprising a damper attached to
said housing.
9. The apparatus of claim 3 wherein said detector comprises a first
combustible gas detector.
10. The apparatus of claim 9 further comprising: a. an oxygen
detector fluidly connected to the interior of said housing; and b.
a pressure detector fluidly connected to the interior of said
housing.
11. The apparatus of claim 10 wherein at least one of said first
combustible gas detector, said oxygen detector and said pressure
detector is located exterior of said housing.
12. The apparatus of claim 11 further comprising: a. a blower
assembly in fluid communication with the interior of said
enclosure; b. a second combustible gas detector located so as to
detect the presence of a combustible gas in or near to an air
intake of said blower assembly; c. a manual shutdown switch located
within said enclosure; and d. a controller in communication with
said first combustible gas detector, said second combustible gas
detector, said oxygen detector, said pressure detector and said
manual shutdown switch, said controller being in communication with
said hot work apparatus and capable of controlling the operation of
said hot work apparatus in response to a signal received from at
least one of said first combustible gas detector, said second
combustible gas detector, said oxygen detector, said pressure
detector and said manual shutdown switch.
13. The apparatus of claim 1 wherein said hot work apparatus
comprises a welding apparatus.
14. The apparatus of claim 1 further comprising an aperture
extending from the interior of said enclosure to an exterior of
said enclosure, said detector being fluidly connected to the
interior of said enclosure through said aperture.
15. The apparatus of claim 14 further comprising a conduit between
said aperture and said detector.
16. The apparatus of claim 1 further comprising a blower assembly
in fluid communication with the interior of said enclosure.
17. The apparatus of claim 1 further comprising a positive pressure
atmosphere within said enclosure.
18. The apparatus of claim 1 further comprising a second detector
for detecting a condition exterior said enclosure.
19. The apparatus of claim 1 wherein said detector comprises a
combustible gas detector.
20. The apparatus of claim 19 wherein said combustible gas detector
is fluidly connected to the interior of said enclosure.
21. The apparatus of claim 19 wherein said combustible gas detector
is in light communication with the interior of said enclosure.
22. The apparatus of claim 19 wherein said combustible gas detector
is in infrared light communication with the interior of said
enclosure.
23. The apparatus of claim 19 wherein said combustible gas detector
is in light communication with air transferred from the interior of
said enclosure to an exterior of said enclosure.
24. The apparatus of claim 19 wherein said combustible gas detector
is in infrared light communication with air transferred from the
interior of said enclosure to an exterior of said enclosure.
25. An apparatus for conducting hot work comprising: a. an
enclosure; b. a blower assembly in fluid communication with an
interior of said enclosure; and c. a means for detecting the
presence of combustible gas that is within said enclosure by
sampling air that is not within said enclosure.
26. The apparatus of claim 25 wherein said air that is not within
said enclosure has been transferred from the interior of said
enclosure.
27. The apparatus of claim 26 further comprising a welding
apparatus operable within said enclosure.
28. The apparatus of claim 27 further comprising a positive
pressure atmosphere within said enclosure.
29. The apparatus of claim 27 wherein said means for detecting the
presence of combustible gas that is within said enclosure by
sampling air that is not within said enclosure comprises a
combustible gas detector located exterior of said enclosure.
30. An apparatus for conducting hot work comprising: a. an
enclosure; b. a first combustible gas detector for detecting
combustible gas within said enclosure; c. an oxygen detector for
detecting oxygen within said enclosure; and d. a pressure detector
for detecting pressure within said enclosure, at least one of said
first combustible gas detector, said oxygen detector and said
pressure detector being located exterior of said enclosure.
31. The apparatus of claim 30 further comprising: a. a blower
assembly in fluid communication with an interior of said enclosure;
b. a second combustible gas detector located so as to detect the
presence of a combustible gas in or near to an air intake of said
blower assembly; c. a welding apparatus operable within said
enclosure, the operation of said welding apparatus being
controllable in response to a signal generated by at least one of
said first combustible gas detector, said second combustible gas
detector, said oxygen detector and said pressure detector.
32. An apparatus for conducting hot work comprising: a. an
enclosure; b. a welding apparatus operable at least partially
within said enclosure; c. a blower assembly in fluid communication
with an interior of said enclosure; d. a manual shutdown switch in
communication with said welding apparatus; e. an oxygen detector
fluidly connected to the interior of said enclosure and in
communication with said welding apparatus; f. a pressure detector
fluidly connected to the interior of said enclosure and in
communication with said welding apparatus; and g. a combustible gas
detector located exterior of said enclosure, said combustible gas
detector being fluidly connected to the interior of said enclosure
such that said combustible gas detector detects the presence of a
combustible gas within said enclosure, said combustible gas
detector being in communication with said welding apparatus.
33. The apparatus of claim 32 wherein said welding apparatus is
shut down in response to a signal generated by at least one of said
oxygen detector, said pressure detector and said combustible gas
detector.
34. A method of terminating hot work within an enclosure
comprising: a. conducting hot work within an enclosure; b.
transferring air from an interior of the enclosure to an exterior
of the enclosure; c. sampling the air transferred from the interior
of the enclosure for the presence of combustible gas; and d.
terminating the hot work within the enclosure in response to
detection of a level of combustible gas in the air transferred from
the interior of the enclosure to the exterior of the enclosure.
35. The method of claim 34 further comprising producing a positive
pressure atmosphere within the enclosure.
36. The method of claim 35 wherein said producing a positive
pressure atmosphere within the enclosure further comprises
transferring air from the exterior of the enclosure to the interior
of the enclosure.
37. The method of claim 36 wherein said terminating hot work within
the enclosure in response to detection of a level of combustible
gas in the air transferred from the interior of the enclosure
further comprises terminating hot work within the enclosure in
response to detection of a level of combustible gas above a
predefined level.
38. The method of claim 37 wherein the predefined level is at most
25% of the lower explosive limit of the combustible gas.
39. The method of claim 34 further comprising forming the enclosure
at a location where hot work is to be conducted on a production
platform that drills for flammable materials.
40. The method of claim 39 further comprising: a. conducting
drilling operations for flammable materials on the production
platform; and b. terminating drilling operations in response to
detection of a level of combustible gas in the air transferred from
the interior of the enclosure.
41. The method of claim 34 further comprising sampling the air
transferred from the interior of the enclosure for the presence of
a level of oxygen.
42. The method of claim 34 wherein said conducting hot work within
an enclosure further comprises conducting welding within the
enclosure.
Description
I. CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 12/412,197 filed on Mar. 26, 2009, which is incorporated by
reference herein in its entirety.
II. BACKGROUND
[0002] A. Technical Field
[0003] An embodiment described herein is an apparatus and method
for conducting hot work.
[0004] B. Background Art
[0005] An embodiment of an apparatus and method for conducting hot
work is described in U.S. Pat. No. 6,783,054 to Pregeant, Jr. et
al., U.S. Pat. No. 7,397,361 to Paulsen, U.S. Pat. No. 7,091,848 to
Albarado, and U.S. Pat. No. 7,193,501 to Albarado, et al., each of
which are hereby incorporated by reference.
III. BRIEF SUMMARY
[0006] An embodiment can be an apparatus for conducting hot work
comprising: an enclosure; a hot work apparatus operable within the
enclosure; and a detector located exterior of the enclosure, the
detector being in detecting communication with the interior of the
enclosure, such that the detector detects the presence of a
condition within the enclosure.
[0007] An embodiment can be an apparatus wherein the hot work
apparatus is shut down in response to the detector detecting the
presence of a predetermined condition within the enclosure.
[0008] An embodiment can be an apparatus further comprising a
housing located adjacent to the enclosure, the interior of the
housing being fluidly connected to the interior of the enclosure,
the detector being fluidly connected to the interior of the
housing.
[0009] An embodiment can be an apparatus further comprising a gap
between the housing and the enclosure.
[0010] An embodiment can be an apparatus wherein the housing is not
in contact with the enclosure.
[0011] An embodiment can be an apparatus wherein the housing is
portable.
[0012] An embodiment can be an apparatus further comprising a stand
attached to the housing.
[0013] An embodiment can be an apparatus further comprising a
damper attached to the housing.
[0014] An embodiment can be an apparatus wherein the detector
comprises a first combustible gas detector.
[0015] An embodiment can be an apparatus further comprising: an
oxygen detector fluidly connected to the interior of the housing;
and a pressure detector fluidly connected to the interior of the
housing.
[0016] An embodiment can be an apparatus wherein at least one of
the first combustible gas detector, the oxygen detector and the
pressure detector is located exterior of the housing.
[0017] An embodiment can be an apparatus further comprising: a
blower assembly in fluid communication with the interior of the
enclosure; a second combustible gas detector located so as to
detect the presence of a combustible gas in or near to an air
intake of the blower assembly; a manual shutdown switch located
within the enclosure; and a controller in communication with the
first combustible gas detector, the second combustible gas
detector, the oxygen detector, the pressure detector and the manual
shutdown switch, the controller being in communication with the hot
work apparatus and capable of controlling the operation of the hot
work apparatus in response to a signal received from at least one
of the first combustible gas detector, the second combustible gas
detector, the oxygen detector, the pressure detector and the manual
shutdown switch.
[0018] An embodiment can be an apparatus wherein the hot work
apparatus comprises a welding apparatus.
[0019] An embodiment can be an apparatus further comprising an
aperture extending from the interior of the enclosure to the
exterior of the enclosure, the detector being fluidly connected to
the interior of the enclosure through the aperture.
[0020] An embodiment can be an apparatus further comprising a
conduit between the aperture and the detector.
[0021] An embodiment can be an apparatus further comprising a
blower assembly in fluid communication with the interior of the
enclosure.
[0022] An embodiment can be an apparatus further comprising a
positive pressure atmosphere within the enclosure.
[0023] An embodiment can be an apparatus further comprising a
second detector for detecting a condition exterior the
enclosure.
[0024] An embodiment can be an apparatus wherein the detector
comprises a combustible gas detector.
[0025] An embodiment can be an apparatus wherein the combustible
gas detector is fluidly connected to the interior of the
enclosure.
[0026] An embodiment can be an apparatus wherein the combustible
gas detector is in light communication with the interior of the
enclosure.
[0027] An embodiment can be an apparatus wherein the combustible
gas detector is in infrared light communication with the interior
of the enclosure.
[0028] An embodiment can be an apparatus wherein the combustible
gas detector is in light communication with air transferred from
the interior of the enclosure to the exterior of the enclosure.
[0029] An embodiment can be an apparatus wherein the combustible
gas detector is in infrared light communication with air
transferred from the interior of the enclosure to the exterior of
the enclosure.
[0030] An embodiment can be an apparatus for conducting hot work
comprising: an enclosure; a blower assembly in fluid communication
with the interior of the enclosure; and a means for detecting the
presence of combustible gas that is within the enclosure by
sampling air that is not within the enclosure.
[0031] An embodiment can be an apparatus wherein the air that is
not within the enclosure has been transferred from the interior of
the enclosure.
[0032] An embodiment can be an apparatus further comprising a
welding apparatus operable within the enclosure.
[0033] An embodiment can be an apparatus further comprising a
positive pressure atmosphere within the enclosure.
[0034] An embodiment can be an apparatus wherein the means for
detecting the presence of combustible gas that is within the
enclosure by sampling air that is not within the enclosure
comprises a combustible gas detector located exterior of the
enclosure.
[0035] An embodiment can be an apparatus for conducting hot work
comprising: an enclosure; a first combustible gas detector for
detecting combustible gas within the enclosure; an oxygen detector
for detecting oxygen within the enclosure; and a pressure detector
for detecting pressure within the enclosure, at least one of the
first combustible gas detector, the oxygen detector and the
pressure detector being located exterior of the enclosure.
[0036] An embodiment can be an apparatus further comprising: a
blower assembly in fluid communication with the interior of the
enclosure; a second combustible gas detector located so as to
detect the presence of a combustible gas in or near to an air
intake of the blower assembly; a welding apparatus operable with
the enclosure, the operation of the welding apparatus being
controllable in response to a signal generated by at least one of
the first combustible gas detector, the second combustible gas
detector, the oxygen detector and the pressure detector.
[0037] An embodiment can be an apparatus for conducting hot work
comprising: an enclosure; a welding apparatus operable at least
partially within the enclosure; a blower assembly in fluid
communication with the interior of the enclosure; a manual shutdown
switch in communication with the welding apparatus; an oxygen
detector fluidly connected to the interior of the enclosure and in
communication with the welding apparatus; a pressure detector
fluidly connected to the interior of the enclosure and in
communication with the welding apparatus; and a combustible gas
detector located exterior of the enclosure, the combustible gas
detector being fluidly connected to the interior of the enclosure
such that the combustible gas detector detects the presence of a
combustible gas within the enclosure, the combustible gas detector
being in communication with the welding apparatus.
[0038] An embodiment can be an apparatus wherein the welding
apparatus is shut down in response to a signal generated by at
least one of the oxygen detector, the pressure detector and the
combustible gas detector.
[0039] An embodiment can be a method of terminating hot work within
an enclosure comprising: conducting hot work within an enclosure;
transferring air from the interior of the enclosure to the exterior
of the enclosure; sampling the air transferred from the interior of
the enclosure for the presence of combustible gas; and terminating
the hot work within the enclosure in response to detection of a
level of combustible gas in the air transferred from the interior
of the enclosure to the exterior of the enclosure.
[0040] An embodiment can be a method further comprising producing a
positive pressure atmosphere within the enclosure.
[0041] An embodiment can be a method wherein producing a positive
pressure atmosphere within the enclosure further comprises
transferring air from the exterior of the enclosure to the interior
of the enclosure.
[0042] An embodiment can be a method wherein terminating hot work
within the enclosure in response to detection of a level of
combustible gas in the air transferred from the interior of the
enclosure further comprises terminating hot work within the
enclosure in response to detection of a level of combustible gas
above a predefined level.
[0043] An embodiment can be a method wherein the predefined level
is at most 25% of the lower explosive limit of the combustible
gas.
[0044] An embodiment can be a method further comprising forming the
enclosure at a location where hot work is to be conducted on a
production platform that drills for flammable materials.
[0045] An embodiment can be a method further comprising: conducting
drilling operations for flammable materials on the production
platform; and terminating drilling operations in response to
detection of a level of combustible gas in the air transferred from
the interior of the enclosure.
[0046] An embodiment can be a method further comprising sampling
the air transferred from the interior of the enclosure for the
presence of a level of oxygen.
[0047] An embodiment can be a method wherein the conducting hot
work within an enclosure further comprises conducting welding
within the enclosure.
[0048] An embodiment can be a method of detecting a combustible gas
entering an enclosure by detecting a pressure drop in the
atmosphere within the enclosure comprising: transferring air from
the exterior of the enclosure to the interior of the enclosure;
detecting a level of combustible gas in or near to a source of the
air transferred from the exterior of the enclosure to the interior
of the enclosure; stopping the transferring of air from the
exterior of the enclosure to the interior of the enclosure in
response to the detecting a level of combustible gas; and detecting
a pressure drop in the atmosphere within the enclosure so as to
detect a combustible gas entering the enclosure.
[0049] An embodiment can be a method further comprising conducting
hot work in the enclosure.
[0050] An embodiment can be a method further comprising terminating
the hot work in the enclosure in response to the detecting a
pressure drop in the atmosphere within the enclosure.
[0051] An embodiment can be a method further comprising
transmitting a signal to a controller in response to the detecting
a pressure drop in the atmosphere within the enclosure.
[0052] An embodiment can be a method further comprising
transmitting a signal from a controller to a power source of the
hot work.
[0053] An embodiment can be a method wherein terminating the hot
work further comprises terminating the hot work in response to a
signal from the controller.
[0054] An embodiment can be an apparatus for conducting hot work
comprising: an enclosure; a hot work apparatus operable within the
enclosure; a blower assembly in fluid communication with the
interior of the enclosure; and a detector located so as to detect
the presence of a condition in or near to an air intake of the
blower assembly, the detector being in communication with the
blower assembly, the detector being isolated from the hot work
apparatus.
[0055] An embodiment can be an apparatus further comprising a first
controller, the first controller being in communication with the
hot work apparatus, the first controller being isolated from the
blower assembly.
[0056] An embodiment can be an apparatus further comprising a
pressure detector fluidly connected to the interior of the
enclosure, the pressure detector being in communication with the
hot work apparatus.
[0057] An embodiment can be an apparatus wherein the pressure
detector is isolated from the blower assembly.
[0058] An embodiment can be an apparatus further comprising a
second controller, the second controller being in communication
with the blower assembly, the second controller being in
communication with the detector.
[0059] An embodiment can be an apparatus further comprising: a
first controller, the first controller being in communication with
the hot work apparatus, the first controller being isolated from
the blower assembly; and a pressure detector fluidly connected to
the interior of the enclosure, the pressure detector being in
communication with the first controller.
[0060] An embodiment can be an apparatus wherein the detector
comprises a combustible gas detector located so as to detect the
presence of a level of combustible gas in or near to an air intake
of the blower assembly.
[0061] An embodiment can be an apparatus further comprising: an
oxygen detector located so as to detect the presence of a level of
oxygen in or near to an air intake of the blower assembly, the
oxygen detector being in communication with the blower assembly,
the oxygen detector being isolated from the hot work apparatus; and
a carbon monoxide detector located so as to detect the presence of
a level of carbon monoxide in or near to an air intake of the
blower assembly, the carbon monoxide detector being in
communication with the blower assembly, the carbon monoxide
detector being isolated from the hot work apparatus.
[0062] The above summary is not intended to describe each
illustrated embodiment or every possible implementation. The
figures and the detailed description which follow exemplify these
embodiments.
IV. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0063] FIG. 1 is a side section view of an embodiment described
herein.
[0064] FIG. 2 is a side section view of an embodiment described
herein.
[0065] FIG. 3 is a side section view of an embodiment described
herein.
[0066] FIG. 4 is a schematic view of an embodiment described
herein.
[0067] FIG. 5 is a schematic view of an embodiment described
herein.
[0068] FIG. 6 is a schematic view of an embodiment described
herein.
V. DETAILED DESCRIPTION OF THE EMBODIMENTS DEPICTED IN THE
DRAWINGS
[0069] As shown in the accompanying drawings, an embodiment is an
apparatus and method for conducting hot work. As shown in FIG. 1,
an embodiment can have an enclosure 10. The enclosure 10 can have a
plurality of sides that define the interior 14 of the enclosure 10
and surround a hot work apparatus 12 that is operable within the
interior 14 of the enclosure 10. The sides of the enclosure 10 can
include ceiling 16, floor 18, left wall 20, right wall 22, rear
wall 24 and a front wall (not shown). The sides of the enclosure 10
can be made of materials such as wood, flame resistant plywood,
fabric, metal, fiberglass, and/or any other suitable materials. In
an embodiment, sides, such as the floor and/or walls, can be flame
resistant plywood that is lined on the interior side with sheet
metal, such as aluminum or steel sheet metal. As opposed to or in
addition to sheet metal, the sides can be lined with one or more
welding blankets. In an embodiment, the floor and a portion of the
walls beginning at the floor and extending upwards about six inches
can be lined with one or more welding blankets. An example of a
welding blanket is sold as item number CF16 under the trademark
PANTHERFELT. In an embodiment, the enclosure 10 can be formed at
locations such as a work site, a petroleum plant, a chemical plant,
a pipeline and/or a production platform. In an embodiment, a
production platform can be a drilling rig that drills for flammable
materials, such as a drilling platform that drills into the earth
for hydrocarbons. The enclosure 10 can also be formed at other
locations, such as any location where it could be desirable to
permanently or temporarily isolate hot work within the enclosure
10. A scaffolding framework can be formed around the enclosure 10
such that the scaffolding framework provides support for the
enclosure 10 and secures the position of the enclosure 10. The
scaffolding framework can be made of materials such as wood, metal,
plastic or any other suitable materials. In an embodiment, the
scaffolding framework can be made of fire retardant wooden
two-by-fours and/or conventional metal scaffolding.
[0070] In an embodiment, the enclosure 10 can be formed adjacent to
flammable materials, such as hydrocarbons contained in tanks, pipes
or other structures. Hot work can be conducted within the enclosure
so that the hot work is isolated from the flammable materials. Hot
work is work that produces a source of ignition, such as arcs,
sparks or flames. The hot work can be conducted within the
enclosure 10 by apparatus such as an arc welder, mig welder, tig
welder, cutting torch, grinder, analyzing equipment, spectrometer
and/or other apparatuses which can produce a source of
ignition.
[0071] The sides of the enclosure 10 can have openings that allow
objects, such as pipes, decking, cables or other objects to pass
through the sides of the enclosure 10. The openings can be formed
by cutting the opening into a side of the enclosure 10 when the
enclosure 10 is being formed, or by forming the sides of the
enclosure around such objects. Any remaining gaps between the sides
of the enclosure 10 and the object can be sealed with a material
such as fire resistant caulk or metal tape.
[0072] In an embodiment, a positive pressure atmosphere is within
the enclosure 10. The positive pressure atmosphere can be produced
within the enclosure 10 by transferring air from the exterior of
the enclosure 10 to the interior 14 of the enclosure 10. In the
embodiments depicted in FIGS. 1, 2 and 3, air is transferred from
the exterior of the enclosure 10 to the interior 14 of the
enclosure 10 by a blower assembly 25 (shown in schematic in FIGS.
4, 5 and 6), which can include blower 26. The blower 26 can be any
device that is capable of producing a flow of air, such as a fan, a
ducted fan, a compressed air source, such as an air compressor
and/or a compressed air tank, an air pump and/or any other suitable
device. In an embodiment, the blower 26 can be an electric,
hydraulic or pneumatic blower. An example of a blower is an Air
MAX-12, produced by COPPUS. In the embodiments depicted in FIGS. 1,
2 and 3, the blower 26 is in fluid communication with the interior
of the enclosure 10 by way of duct 28. An air intake 30 of the
blower 26 can be located at an area believed to be free of
combustible gases, such as unclassified area of a drilling
platform. In operation, air is transferred from the exterior of the
enclosure 10 to the interior 14 of the enclosure 10 by passing
through air intake 30 traveling through duct 28 and into the
enclosure 10 at inlet aperture 32.
[0073] Referring to the embodiment depicted in FIG. 1, a positive
pressure atmosphere within the enclosure 10 can cause air to be
transferred from the interior 14 of the enclosure 10 to the
exterior of the enclosure 10 by passing through an aperture, such
as outlet aperture 34, which extends from the interior 14 of the
enclosure 10 to the exterior of the enclosure 10. As shown in the
embodiment depicted in FIGS. 1 and 3, the outlet aperture 34 can be
approximately the same size as inlet aperture 32. In an embodiment,
the outlet aperture 34 can be larger or smaller than the inlet
aperture 32. As shown in the embodiment depicted in FIG. 3, a grill
36, such as a spark arresting filter, can be placed across outlet
aperture 34. In an embodiment, the spark arresting filter can
include a Flame Gard 1 produced by FLAME GARD. The grill 36 can
hamper or prevent sources of ignition, such as sparks that can be
created by hot work, from passing through the outlet aperture 34.
One or more grills can also be placed across other apertures that
may exist in the sides of the enclosure 10 or the housing 38.
[0074] Referring to the embodiment depicted in FIG. 1, a housing 38
can be located adjacent to the enclosure 10. The housing 38 can
have a plurality of housing sides that define the interior 42 of
the housing 38. The housing sides of the housing 38 can include
housing ceiling 44, housing floor 46, housing left wall 48, housing
right wall 50, housing rear wall 52 and a housing front wall (not
shown). A housing side of housing 38 can have an aperture, such as
a housing inlet aperture 40, located adjacent to outlet aperture 34
so as to allow a fluid connection between the interior 14 of the
enclosure 10 and the interior 42 of the housing 38. The housing
inlet aperture 40 can be approximately the same size as the outlet
aperture 34 of the enclosure. The housing inlet aperture 40 can
also be larger (see FIG. 1) or smaller than the outlet aperture 34.
Housing 38 can also have a damper 54 attached to the housing 38.
The damper 54 can provide an aperture that allows air to be
transferred from the interior 42 of the housing 38 to the exterior
of the housing 38 by passing through damper 54. The damper 54 can
be a device such as a louver or valve and can have adjustable vents
that can allow the flow of air through the damper 54 to be
regulated. Air transferred from the interior 14 of the enclosure 10
to the interior 42 of the housing 38 can create a positive pressure
atmosphere within the housing 38. The pressure level of a positive
pressure atmosphere within the enclosure 10 and the housing 38 can
be regulated or partially regulated by adjusting the vents of the
damper 54. For example, to increase the pressure level of the
positive pressure atmosphere within the enclosure 10 and the
housing 38, the vents of the damper 54 could be closed or partially
closed. To decrease the pressure level of the positive pressure
atmosphere within the enclosure 10 and the housing 38, the vents of
the damper 54 could be opened or partially opened. In an
embodiment, the damper 54 can include a grill, such as a spark
arresting filter. In the embodiment depicted in FIGS. 1 and 3,
although some air may spill out of gap 56 between the housing 38
and the enclosure 10, adjusting the vents of the damper 54 can
still have an effect on the pressure level of the positive pressure
atmosphere within the enclosure 10 when the housing inlet aperture
40 is placed sufficiently near the outlet aperture 34 of the
enclosure 10.
[0075] In an embodiment the positive pressure atmosphere within the
enclosure 10 causes air to be transferred from the interior 14 of
the enclosure 10 to the exterior of the enclosure 10 and into the
interior 42 of the housing 38, and then from the interior 42 of the
housing 38 to the exterior of the housing 38. In an embodiment, an
air moving device, such as a fan, can be positioned at a location
such as in or adjacent to outlet aperture 34, housing inlet
aperture 40, conduit 58 (discussed below) and/or damper 54. The air
moving device can cause air to be transferred from the interior 14
of the enclosure 10 to the exterior of the enclosure 10 and into
the interior 42 of the housing 38, and then from the interior 42 of
the housing 38 to the exterior of the housing 38.
[0076] Referring to the embodiments depicted in FIGS. 1 and 3, the
housing 38 is not in contact with the enclosure 10 and can have a
gap 56 between the housing 38 and the enclosure 10. In the
embodiment depicted in FIG. 2, a conduit 58, such as ductwork,
tubing or pipe, connects the housing 38 to the enclosure 10. The
conduit 58 can be connected to the enclosure 10 by any means in the
art. For example, as shown in FIG. 2, a flange 59 can connect the
conduit 58 to an exterior of a wall of the enclosure 10. Referring
to the embodiments depicted in FIGS. 1, 2 and 3, a stand 60 is
attached to the housing 38. The stand 60 can be placed on a
foundation, such as a deck of a drilling platform. The stand 60 can
also be secured to the foundation which can increase stability. The
housing 38 can be portable and can be moved to different locations
that can be adjacent to an aperture in the sides of the enclosure
10. For example, an aperture can be drilled, cut or otherwise
formed in a side of the enclosure 10 at a location so as to
position a hot work apparatus 12 that is operable within the
enclosure 10, generally in a line between inlet aperture 32 and
outlet aperture 34. The housing 38 can then be placed so that
housing inlet aperture 40 is adjacent to outlet aperture 34. If the
location of the hot work within the enclosure 10 is changed, a new
aperture can be formed in a side of the enclosure 10 at a location
so as to position the hot work generally in a line between inlet
aperture 32 and the newly formed aperture. The housing 38 can then
be moved and placed in a location so that housing inlet aperture 40
is adjacent to the newly formed aperture. The housing 38 can also
be moved to different locations on a drilling platform or different
work sites.
[0077] Referring to the embodiments depicted in FIGS. 1, 2 and 3,
detectors 62, 64, 66, 68, 70, 72, 74, 76, 78 and 80 are located
exterior of the enclosure 10. Detectors 62, 64, 66, 68, 70, 72, 74,
76, 78 and 80 are in detecting communication with the interior 14
of the enclosure 10, such that the detectors detect the presence of
a condition within the enclosure 10. In an embodiment, the presence
of a condition can include detecting conditions such as a level of
toxic gas, a level of combustible gas, a level of oxygen, a level
of carbon monoxide, a level of hydrogen sulfide and/or other gases.
The presence of a condition can also include detecting conditions
such as a level of pressure, humidity, temperature and/or any other
condition. As an example, the detectors can be mechanical,
solid-state, chemical, electrochemical, electric, optical,
infrared, photoionization, catalytic bead and/or any other type of
detector. Depending on the detectors selected, the detectors can
perform the detection function in various ways, for example by air
sampling, pressure sensing, light absorption or any other way.
[0078] In the embodiments depicted in FIGS. 1 and 3, detectors 62,
64 and 66 are located exterior of the enclosure 10 and exterior of
the housing 38, and are in detecting communication with the
interior 14 of the enclosure 10 by being fluidly connected to the
interior 14 of the enclosure 10. Detectors 62, 64 and 66 are
fluidly connected to the interior 14 of the enclosure 10 by being
fluidly connected to the interior 42 of the housing 38, which is
itself fluidly connected to the interior 14 of the enclosure 10. In
the embodiment depicted in FIG. 2, detectors 68, 70 and 72 are
located exterior of the enclosure 10 and within the interior 42 of
the housing 38, and are in detecting communication with the
interior 14 of the enclosure 10 by being fluidly connected to the
interior 14 of the enclosure 10. Detectors 68, 70 and 72 are
fluidly connected to the interior 14 of the enclosure 10 by being
fluidly connected to the interior 42 of the housing 38, which is
itself fluidly connected to the interior 14 of the enclosure 10.
Still referring to the embodiment depicted in FIG. 2, detectors 74,
76 and 78 are located exterior of the enclosure 10 and are attached
to the exterior side of right wall 22, and are in detecting
communication with the interior 14 of the enclosure 10 by being
fluidly connected to the interior 14 of the enclosure 10 through
apertures in right wall 22. Detector 80 is attached to the exterior
side of right wall 22 and is in detecting communication with the
interior 14 of the enclosure 10 by being in light communication
with the interior 14 of the enclosure 10 through a glass window 82
in right wall 22.
[0079] Referring to the embodiments depicted in FIGS. 1, 2 and 3,
detectors 62, 68, 74 and 80 can be combustible gas detectors. In an
embodiment, a combustible gas detector can be any device that is
capable of detecting combustible gas. An example of a combustible
gas detector is a matched pair catalytic bead detector, such as
model number FP-524C produced by DETCON Incorporated. The
combustible gas detectors can detect the presence of combustible
gases, such as fuel gases and/or hydrocarbon gases. Combustible gas
detectors 62, 68 and 74 can be fluidly connected to the interior 14
of the enclosure 10 and can sample air transferred from the
interior 14 of the enclosure 10 to the exterior of the enclosure 10
for the presence of combustible gas. By sampling air transferred
from the interior 14 of the enclosure 10 to the exterior of the
enclosure 10, the combustible gas detector can detect the presence
of combustible gas within the enclosure 10. Another combustible gas
detector 86 can be located so as to detect the presence of a
combustible gas in or near to the air intake 30 of the blower 26.
As used herein, a detector, such as combustible gas detector 86, is
located so as to detect the presence of a condition, such as
combustible gas, near to the air intake 30 of the blower 26 if the
detector is capable of detecting a condition that is more likely
than not to be transferred into the air intake 30 of the blower
26.
[0080] Referring to FIG. 2, detector 80 can be an infrared
detector, such as an infrared combustible gas detector. An example
of an infrared combustible gas detector is produced by DETCON Inc.
under the model number IR-622. An infrared combustible gas detector
80 can be located exterior of the enclosure 10 and can transmit
infrared light into the interior 14 of the enclosure 10, such as
through a glass window 82 formed in a side of the enclosure 10. A
mirror 84 can be placed within the enclosure 10 such that light
transmitted by the infrared combustible gas detector 80 can reflect
off of the mirror 84 and return to the infrared combustible gas
detector 80. Since combustible gases such as combustible
hydrocarbon gases can have different infrared absorption spectra,
the infrared combustible gas detector can analyze the reflected
infrared light to detect the presence of combustible hydrocarbon
gas within the enclosure 10. In an embodiment, an infrared
combustible gas detector can be located in or adjacent to housing
38 so as to be in infrared light communication with air transferred
from the interior 14 of the enclosure 10 to the exterior of the
enclosure 10. By sampling air transferred from the interior 14 of
the enclosure 10 to the exterior of the enclosure 10, the infrared
combustible gas detector can detect the presence of combustible gas
within the enclosure 10.
[0081] Referring still to the embodiments depicted in FIGS. 1, 2
and 3, detectors 64, 70, and 76 can be oxygen detectors and/or
carbon monoxide detectors. In an embodiment, the oxygen detectors
and/or carbon monoxide detectors can be any device that is capable
of detecting oxygen and/or carbon monoxide. An example of an oxygen
detector is a galvanic metal air battery detector, such as model
number DM-534 produced by DETCON Incorporated. An example of a
carbon monoxide detector is an electrochemical fuel cell detector,
such as model number DM-500IS-CO produced by DETCON Incorporated.
Oxygen and/or carbon monoxide detectors 64, 70 and 76 can be
fluidly connected to the interior 14 of the enclosure 10 and can
sample air transferred from the interior 14 of the enclosure 10 to
the exterior of the enclosure 10. By sampling air transferred from
the interior 14 of the enclosure 10 to the exterior of the
enclosure 10, the oxygen and/or carbon monoxide detectors can
detect the presence of oxygen and/or carbon monoxide within the
enclosure 10.
[0082] Referring still to the embodiments depicted in FIGS. 1, 2
and 3, detectors 66, 72 and 78 can be pressure detectors. The
pressure detectors can be any device that is capable of detecting
pressure and/or a change in pressure. An example of pressure
detector is model number 616D produced by DWYER. Pressure detectors
64, 70 and 76 can be fluidly connected to the interior 14 of the
enclosure 10 and can detect a level of pressure in the atmosphere
within the interior 14 of the enclosure 10 and/or a pressure drop
in the atmosphere within the interior 14 of the enclosure 10. Since
pressure detectors 66 and 72 are fluidly connected to the interior
14 of the enclosure 10 by being fluidly connected to the interior
42 of the housing 38, pressure detectors 66 and 72 can detect a
level of pressure in the atmosphere within the enclosure 10 and/or
a pressure drop in the atmosphere within the enclosure 10 by
detecting a level of pressure in the atmosphere within the housing
38 and/or a pressure drop in the atmosphere within the housing
38.
[0083] In an embodiment, one or more detectors can be located so as
to detect the presence of a condition in or near to the air intake
30 of the blower 26. In the embodiments depicted in FIGS. 1, 2 and
3, detector 86 can be a combustible gas detector, detector 96 can
be a carbon monoxide detector and detector 98 can be an oxygen
detector. In an embodiment, a combustible gas detector, an oxygen
detector, a carbon monoxide detector and a hydrogen sulfide
detector can be located so as to detect the presence of a condition
in or near to the air intake 30 of the blower 26; in addition, an
oxygen detector, a carbon monoxide detector, a hydrogen sulfide
detector and a pressure detector can be in detecting communication
with the interior 14 of the enclosure 10.
[0084] Referring to the embodiments depicted in FIGS. 1, 2 and 3,
each of detectors 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 86, 96
and 98 are located exterior of the enclosure 10. In another
embodiment, one or more, or each of detectors 62, 64, 66, 68, 70,
72, 74, 76, 78, 80, 86, 96 and 98, can be located within the
interior 14 of the enclosure 10. It should also be understood that
the conditions detected and the detectors, including the number
and/or type of detectors described herein, are exemplary of
numerous conditions, detectors and configurations that may fall
within the scope of the appended claims.
[0085] One or more of detectors 62, 64, 66, 68, 70, 72, 74, 76, 78,
80, 86, 96 and 98 can be in communication, such as wired or
wireless communication, with a hot work apparatus 12, such as a
power source of the hot work apparatus. In response to one or more
of detectors 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 86, 96 and 98
detecting the presence of a condition, the detector can generate a
signal that is transmitted to the hot work apparatus so as to
terminate the hot work and/or cause the hot work apparatus to shut
down. For example, the detectors can generate a signal in response
to detecting the presence of a predetermined condition, such as a
predefined level of oxygen, combustible gas, carbon monoxide,
hydrogen sulfide, pressure and/or other conditions. In an
embodiment a predefined level of oxygen can be a trace amount of
oxygen that is at or near the detection capabilities of the
detector. In another embodiment, the predefined level of oxygen can
be a level of oxygen below 19.5% and/or above 23.5%.
[0086] As an additional example, detectors 62, 68 and 74 can
generate a signal that is capable of terminating hot work within
the enclosure in response to detecting the presence of a
predetermined condition, such as a predefined level of combustible
gas in the air transferred from the interior 14 of the enclosure 10
to the exterior of the enclosure 10. In an embodiment, the
predefined level of combustible gas can be a trace amount of
combustible gas that is at or near the detection capabilities of
the detector. In another embodiment, the predefined level of
combustible gas can be a percentage of the lower explosive limit of
the combustible gas. The predefined level can be percentages such
as 5%, 10%, 15%, 20% or 25% of the lower explosive limit of the
combustible gas. The lower explosive limit (also known as the lower
flammable limit) is the leanest percentage of combustible gas mixed
with air that is explosive. Examples of possible lower explosive
limits of some gases are provided in the following chart:
TABLE-US-00001 "Lower Explosive or Flammable Limit" GAS
(LEL/LFL)/(%) Acetaldehyde 4 Acetone 2.6 Acetylene 2.5 Ammonia 15
Arsine 5.1 Benzene 1.35 n-Butane 1.86 iso-Butane 1.80 iso-Butene
1.8 Butylene 1.98 Carbon Disulfide 1.3 Carbon Monoxide 12
Cyclohexane 1.3 Cycloproprane 2.4 Diethyl Ether 1.9 Ethane 3
Ethylene 2.75 Ethyl Alcohol 3.3 Ethyl Chloride 3.8 Fuel Oil No. 1
0.7 Hydrogen 4 Isobutane 1.8 Isopropyl Alcohol 2 Gasoline 1.4
Kerosine 0.7 Methane 5 Methyl Alcohol 6.7 Methyl Chloride 10.7
Methyl Ethyl Ketone 1.8 Naphthalene 0.9 n-Heptane 1.0 n-Hexane 1.25
n-Pentene 1.65 Neopentane 1.38 Neohexane 1.19 n-Octane 0.95
iso-Octane 0.79 n-Pentane 1.4 iso-Pentane 1.32 Propane 2.1
Propylene 2.0 Silane 1.5 Styrene 1.1 Toluene 1.27 Triptane 1.08
p-Xylene 1.0
[0087] In an embodiment, a detector generates a signal in response
to the detector detecting a level of combustible gas of at most 25%
of the lower explosive limit of the combustible gas. For example,
referring to the chart above it can be seen that methane has a
lower explosive limit of 5%. 25% of the lower explosive limit of
methane would be 1.25% methane mixed in air. In this embodiment,
the detector would not generate a signal that caused the hot work
within the enclosure to terminate until the detector detected a
concentration of methane in air of 1.25%.
[0088] As opposed to, or in addition to, being in communication
with the hot work apparatus 12, one or more of detectors 62, 64,
66, 68, 70, 72, 74, 76, 78, 80, 86, 96 and 98, such as combustible
gas detector 86, carbon monoxide detector 96 and oxygen detector
98, can be in communication with the blower assembly 25. For
example, as shown in FIGS. 5 and 6, detectors 86, 96 and 98 can be
isolated from the hot work apparatus 12 and can be in communication
with the blower assembly 25, such as the blower 26 and/or a shut
off valve of the blower assembly 25 that can be located within duct
28. As the term "isolated" is used herein, a first component, such
as detectors 86, 96 and/or 98 is isolated from a second component,
such as hot work apparatus 12 and/or a controller (described below)
if the first and second component are not directly or indirectly in
wired or wireless communication with each other. As used herein, a
first component is indirectly in wired or wireless communication
with a second component if one or more additional components
interconnect the first component and the second component by wired
or wireless communication. For example, if a first component is in
direct wired communication with a controller, and the controller is
in direct wired communication with a second component, then the
first and second component are in indirect wired communication with
each other. As used herein, wireless communication is defined as
communication via electromagnetic radiation, such as radio waves,
infrared light and/or any other form of electromagnetic radiation.
In response to detecting a level of combustible gas, a level of
carbon monoxide and/or a level of oxygen in or near to a source of
air transferred from the exterior of the enclosure 10 to the
interior 14 of the enclosure 10, detector 86, 96 and/or 98 can
generate a signal which causes the transfer of air from the
exterior of the enclosure 10 to the interior 14 of the enclosure 10
to be stopped, such as by shutting down the blower 26 of the blower
assembly 25 and/or closing the shut off valve of the blower
assembly 25 and diverting or blocking the flow of air through duct
28. The transfer of air from the exterior of the enclosure 10 to
the interior 14 of the enclosure 10 could, for example, be stopped
by transmitting a signal to a switch of the blower assembly 25,
such as an interface relay. An example of an interface relay is
model number 750XBXH-24D produced by MAGNECRAFT.
[0089] One or more of detectors 62, 64, 66, 68, 70, 72, 74, 76, 78,
80, 86, 96 and 98 can be in communication, such as wired or
wireless communication, with a controller 88. As shown in the
embodiment depicted in FIG. 4, each of the detectors can be in
communication with the controller 88. The controller can include
devices such as a computer, a programmable logic controller or any
other suitable device. An example of a controller is a model number
S7200 programmable logic controller produced by SIEMENS. The
controller 88 can be located in the interior 14 of the enclosure 10
or can be located exterior of the enclosure 10. In an embodiment,
the controller 88 can be attached to housing 38. The controller 88
can receive signals generated by one or more of detectors 62, 64,
66, 68, 70, 72, 74, 76, 78, 80, 86, 96 and 98 in response to the
detectors detecting the presence of a condition. The controller can
then process the signals received from the detectors and can
generate a second signal which is transmitted to the hot work
apparatus 12 and terminates the hot work and/or causes the hot work
apparatus 12 to shut down. For example, detectors 62, 68 and 74 can
generate an input signal in response to detecting the presence of a
predetermined condition, such as a predefined level of combustible
gas in the air transferred from the interior 14 of the enclosure 10
to the exterior of the enclosure 10. The input signal can be
transmitted to the controller 88, which can process the input
signal. The controller 88 can then transmit an output signal to the
hot work apparatus 12, such as a switch, relay, solenoid valve or
other suitable device of the hot work apparatus 12, which
terminates the hot work and/or causes the hot work apparatus to
shut down; and/or the controller 88 can then transmit an output
signal to the blower assembly 25, which causes the transfer of air
from the exterior of the enclosure 10 to the interior 14 of the
enclosure 10 to be stopped, such as by shutting down the blower 26
of the blower assembly 25 and/or closing the shut off valve of the
blower assembly 25. The controller 88 can include a display screen
which can display information, such as the status of the detectors
or other components that are in communication with the controller
88. The display screen can be within the interior 14 of the
enclosure 10, or can be exterior of the enclosure. In an
embodiment, a first display screen of the controller 88 can be
attached to the housing 38 and a second display screen of the
controller 88 can be located within the interior 14 of the
enclosure 10. The first and/or second display screen can be in
communication, such as by wired or wireless communication, with the
controller 88. In an embodiment, the display screen can be a model
TP 270 touch screen display produced by SIEMENS.
[0090] As shown in FIGS. 5 and 6, detectors 86, 96 and/or 98 can be
isolated from controller 88 and the hot work apparatus 12, and can
be in communication with the blower assembly 25, such as a switch,
relay, solenoid valve or other suitable device of the blower
assembly 25. In the embodiment depicted in FIG. 6, detectors 86, 96
and 98 are in direct communication with the blower assembly 25. In
the embodiment depicted in FIG. 5, detectors 86, 96 and 98 are in
communication with the blower assembly 25 by being in communication
with a second controller 100, which is itself in communication with
the blower assembly 25. In an embodiment, the second controller 100
can be of a similar or identical type as controller 88. In an
embodiment, detecting a condition such as combustible gas, carbon
monoxide and/or oxygen entering the enclosure 10 can be
accomplished by shutting down the blower assembly 25 in response to
one or more of detectors 86, 96 and 98 detecting a condition, and
then by detecting the resulting pressure drop in the atmosphere
within the enclosure 10 so as to detect a condition entering the
enclosure 10.
[0091] An alarm 94 such as a visual and/or audio alarm, can also be
in communication with the detectors, the controller 88 and/or the
second controller 100, and can be triggered in response to a signal
received from the detectors, the controller 88 and/or the second
controller 100.
[0092] Oxygen and/or carbon monoxide detectors 64, 70, and 76 can
be in communication with the hot work apparatus 12, the blower
assembly 25, the controller 88, the second controller 100 and/or
the alarm 94. Additionally, pressure detectors 66, 72, and 78
and/or any other detectors can be in communication with the hot
work apparatus 12, the blower assembly 25, the controller 88, the
second controller 100 and/or the alarm 94.
[0093] An interior manual shut down switch 90 and/or an exterior
manual shutdown switch 92 can be connected to the hot work
apparatus 12, the blower assembly 25, the controller 88, the second
controller 100 and/or the alarm 94. The interior manual shut down
switch 90 and/or the exterior manual shutdown switch 92 can be
devices such as a switch, button, lever, knob, toggle or any other
device that, when triggered, can shut down the hot work apparatus
12, activate the alarm 94 and/or shut down the blower assembly 25.
The interior manual shut down switch 90 and/or an exterior manual
shutdown switch 92 can be triggered by a user, such as one or more
persons designated as a firewatch, who is within the enclosure 10
and/or exterior of the enclosure 10. One or more additional manual
shut down switches can be located within the interior of the
enclosure 10 and/or exterior to the enclosure 10.
[0094] As used herein, the detectors, controller 88, second
controller 100, interior manual shut down switch 90 and/or exterior
manual shut down switch 92 are in communication with the hot work
apparatus 12, the blower assembly 25 and/or the alarm 94 if a
signal generated by the detectors, controller 88, second controller
100, interior manual shut down switch 90 and/or exterior manual
shut down switch 92 results in terminating the hot work, stopping
the transfer of air from the exterior of the enclosure 10 to the
interior 14 of the enclosure 10 and/or activates the alarm 94.
[0095] In an embodiment, the housing inlet aperture 40 of two or
more housings 38 can be placed adjacent to apertures in the sides
of the enclosure 10 at various locations. For example, the housing
inlet aperture 40 of a first housing 38 can be placed adjacent to
an aperture near the ceiling 16 of the enclosure 10, so as to
detect combustible gases for example that are lighter than air. The
housing inlet aperture 40 of a second housing 38 can be placed
adjacent to an aperture near the floor 18 of the enclosure 10, so
as to detect combustible gases for example that are heavier than
air.
[0096] Referring to the embodiments depicted in FIGS. 1 and 3, the
distance between the housing 38 and the enclosure 10, such as the
distance between the housing inlet aperture 40 and outlet aperture
34, can be a distance that can maintain a positive pressure
atmosphere within the enclosure 10 and/or can maintain a positive
pressure atmosphere within the housing 38. When air is being
transferred from the exterior of the enclosure 10 to the interior
14 of the enclosure 10, such as by blower assembly 25, the pressure
level of the positive pressure atmosphere within the enclosure 10
and the housing 38 can be reduced by increasing the distance
between the housing 38 and the enclosure 10. The pressure level of
the positive pressure atmosphere within the enclosure 10 and the
housing 38 can be increased by decreasing the distance between the
housing 38 and the enclosure 10. In an embodiment, the distance
between the housing 38 and the enclosure 10 can be fractions of a
centimeter. The distance between the housing 38 and the enclosure
10 can also be varied as described above so that all or
substantially all of the air that enters the housing 38 is air that
has been transferred from the interior 14 of the enclosure 10.
[0097] In an embodiment, the enclosure 10 can also have an entry
way, such as a door, that can allow a person to enter and exit the
enclosure 10. The entry way can include an air lock that can allow
a person to enter and exit the enclosure 10 with little or no
pressure drop in the positive pressure atmosphere within the
enclosure 10. The air lock can be a separate chamber from the
enclosure 10 and can have a conduit interconnecting the interior 14
of the enclosure 10 and the interior of the air lock. The conduit
can have a valve that can be opened or closed to allow the pressure
differential between the interior 14 of the enclosure 10 and the
interior of the air lock to be equalized. In an embodiment, blower
assembly 25 can be in fluid communication with the interior of the
air lock, such as by a second duct, and can create a positive
pressure atmosphere within the air lock. In an embodiment, a second
blower assembly can be in fluid communication with the interior of
the air lock, and can create a positive pressure atmosphere within
the air lock. When a person enters the air lock from the exterior
of enclosure 10 and closes an exterior door of the air lock, a
short period of time will elapse while the pressure in the air lock
increases to a pressure level equal to or greater than the pressure
level inside of the enclosure 10. Once this condition occurs, the
person can then open the door to enclosure 10 and enter enclosure
10 without causing a pressure drop within enclosure 10, thereby
causing a spurious shut down of hot work within the enclosure 10.
Likewise, a person exiting enclosure 10 can enter the air lock and
close the door to the enclosure 10 before opening the exterior door
of the air lock to exit the air lock, thereby preventing a spurious
shutdown of hot work operations. In an embodiment, pressure
detectors can detect the level of pressure within the air lock and
can allow for the pressure differential between the interior of the
air lock and the interior 14 of the enclosure 10 to be determined
and/or displayed to a person entering or exiting the enclosure
10.
[0098] In operation of an embodiment, enclosure 10 can be formed at
a location where hot work will be conducted within the enclosure
10. Blower assembly 25 can be activated to transfer air from the
exterior of the enclosure 10 to the interior 14 of the enclosure 10
and produce a positive pressure atmosphere within the enclosure 10.
Once a positive pressure atmosphere is produced within the
enclosure 10, hot work can be conducted within the enclosure 10.
The positive pressure atmosphere within the enclosure can cause air
to be transferred from the interior 14 of the enclosure 10 to the
exterior of the enclosure, and into the interior 42 of housing 38.
The air transferred from the interior 14 of the enclosure 10 to the
interior 42 of the housing 38 can then be sampled by detectors 62,
64, 66, 68, 70 and/or 72 for the presence of a condition, such as a
level of combustible gas, oxygen and/or pressure. The positive
pressure atmosphere within the housing 38 can then cause the air to
be transferred from the interior 42 of the housing 38 to the
exterior of the housing 38 through damper 54. If detectors 62, 64,
66, 68, 70, 72, 74, 76, 78, 80, 86, 96 and/or 98 detects the
presence of a condition, one or more of the detectors can generate
a signal which results in hot work within the enclosure 10 and/or
the transfer of air from the exterior of the enclosure 10 to the
interior 14 of the enclosure being automatically terminated. A
person can then view a display screen of the controller 88 to
determine the cause of the automatic shut down. Once the cause of
the automatic shut down has been determined and remedied, the above
process can be repeated.
[0099] In an embodiment, a first person, such as a firewatch, can
be outside of the enclosure 10 and can have fire-fighting
equipment, a radio and a combustible gas detector. The first person
can monitor the enclosure and/or other components described herein
for at least half an hour prior to, during and at least half an
hour after hot work is conducted within the enclosure 10. The first
person can also terminate the hot work within the enclosure 10 by
activating the exterior manual shut down switch 92. In an
embodiment, the hot work can be conducted on a production platform,
and the first person can be in close proximity to an emergency shut
down station of the production platform. The first person can
activate the emergency shut down station, which can terminate
operations on the production platform as well as terminate the hot
work within the enclosure 10. A second person, such as a firewatch,
can be inside of the enclosure 10 and can monitor the level of
combustible gas, the level of oxygen and/or other gases within the
enclosure 10. The second person can terminate the hot work within
the enclosure 10 by activating the interior manual shut down switch
90. Lights and a radio can be located within the enclosure 10 and
can have an independent power source that allows the lights and
radio to function even if power to the enclosure 10 is shut down. A
fire extinguisher, such as a 30 pound (13.61 kilogram) fire
extinguisher, can also be located within the enclosure 10. Prior to
conducting hot work within the enclosure 10, the detectors can be
calibrated and/or drills can be conducted to determine whether the
methods and apparatuses described herein are functioning
properly.
[0100] Referring to FIG. 4, combustible gas detector 86, carbon
monoxide detector 96, oxygen detector 98 and blower assembly 25 are
in communication with controller 88. In response to one or more of
detectors 86, 96 and 98 detecting a condition, such as detector 86
detecting a level of combustible gas in or near to a source of air
being transferred from the exterior of the enclosure to the
interior of the enclosure by blower assembly 25, combustible gas
detector 86 can generate a signal which is transmitted to
controller 88. The controller 88 can then stop the transfer of air
from the exterior of the enclosure to the interior of the
enclosure, such as by sending a signal to blower assembly 25 which
causes the blower assembly 25 to shut down. As opposed to each of
detectors 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 86, 96 and/or 98
being in communication with the controller 88 (as shown in FIG. 4),
one or more of the detectors can be isolated from the controller
88, and can be in communication with the hot work apparatus 12, the
blower assembly 25, the second controller 100 and/or the alarm
94.
[0101] An embodiment is a method of detecting a condition such as a
combustible gas entering the enclosure 10 by detecting a pressure
drop in the atmosphere within the enclosure 10. Referring now to
FIGS. 5 and 6, combustible gas detector 86, carbon monoxide
detector 96 and oxygen detector 98 are in communication with blower
assembly 25. The detectors 86, 96 and 98, and the blower assembly
25 are isolated from the controller 88 and the hot work apparatus
12. As shown in FIGS. 5 and 6, pressure detectors 66, 72 and 78 are
in communication with the controller 88. Referring now to FIGS. 1,
2 and 3, in an embodiment, detecting a condition such as a
combustible gas entering the enclosure 10 by detecting a pressure
drop in the atmosphere within the enclosure 10 can be accomplished
by: transferring air from the exterior of the enclosure 10 to the
interior 14 of the enclosure 10, such as by blower assembly 25;
detecting a level of combustible gas in or near to a source of the
air transferred from the exterior of the enclosure 10 to the
interior 14 of the enclosure 10, such as by combustible gas
detector 86; stopping the transferring of air from the exterior of
the enclosure 10 to the interior 14 of the enclosure 10 in response
to the detecting a level of combustible gas, such as by combustible
gas detector 86 generating a signal which results in blower
assembly 25 shutting down; and detecting a pressure drop in the
atmosphere within the enclosure 10 so as to detect a combustible
gas entering the enclosure 10, such as by pressure detectors 66, 72
and/or 78. Since detecting a pressure drop in the atmosphere within
the enclosure 10 can indicate that a combustible gas is entering
the enclosure 10, the above method can allow for the detection a
combustible gas entering the enclosure 10 by detecting a pressure
drop in the atmosphere within the enclosure 10. In an embodiment,
in response to detecting a pressure drop in the atmosphere within
the enclosure 10, one or more of the pressure detectors can send a
signal to the controller 88. In response to receiving the signal
from one or more of the pressure detectors, the controller 88 can
indicate that combustible gas was detected entering the enclosure
10 by displaying a message on a display screen of the controller
88. In an embodiment, the entry way of the enclosure 10 can include
an air lock, such as the air lock described above, that can reduce
or eliminate the chance that the controller 88 incorrectly
indicates that combustible gas was detected entering the enclosure
10. Further, hot work being conducted within the enclosure 10 can
be terminated in response to the detecting a pressure drop in the
atmosphere within the enclosure 10, such as by one or more of the
pressure detectors generating a signal that results in the hot work
being terminated. Although the above method can allow for the
detection of a condition, such as a combustible gas, entering the
enclosure 10 by detecting a pressure drop in the atmosphere within
the enclosure 10, a pressure drop in the atmosphere within the
enclosure 10 can also be caused by circumstances other than
detection of a condition entering the enclosure. For example, the
blower assembly 25 could malfunction and shut down, or an opening
could be formed in the sides of the enclosure 10 that caused the
interior 14 of the enclosure 10 to depressurize; in such a
circumstance detecting a pressure drop in the atmosphere within the
enclosure 10 would not be detecting a condition entering the
enclosure 10.
[0102] The embodiments shown in the drawings and described above
are exemplary of numerous embodiments that may be made within the
scope of the appended claims. It is contemplated that numerous
other configurations may be used, and the material of each
component may be selected from numerous materials other than those
specifically disclosed. In short, it is the applicant's intention
that the scope of the patent issuing herefrom will be limited only
by the scope of the appended claims.
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