U.S. patent number 3,608,873 [Application Number 04/866,446] was granted by the patent office on 1971-09-28 for mechanically assisted spiral-draft water-cooling tower.
This patent grant is currently assigned to Fluor Products Company, Inc.. Invention is credited to Donn B. Furlong.
United States Patent |
3,608,873 |
Furlong |
September 28, 1971 |
MECHANICALLY ASSISTED SPIRAL-DRAFT WATER-COOLING TOWER
Abstract
A forced-draft cooling tower employs fans, passages to receive
fan-displaced air or gas, and packing sections spaced about the
tower axis so that positive swirling of the gas or air about that
axis within the tower interior is produced as the flow passes
through the passages and packing sections.
Inventors: |
Furlong; Donn B. (Santa Rosa,
CA) |
Assignee: |
Fluor Products Company, Inc.
(Santa Rosa, CA)
|
Family
ID: |
25347643 |
Appl.
No.: |
04/866,446 |
Filed: |
October 15, 1969 |
Current U.S.
Class: |
261/30; 165/900;
261/79.2; 261/111; 165/125; 261/DIG.11 |
Current CPC
Class: |
F28C
1/04 (20130101); F28F 25/12 (20130101); Y10S
261/11 (20130101); Y10S 165/90 (20130101); Y02B
30/70 (20130101) |
Current International
Class: |
F28F
25/00 (20060101); F28F 25/12 (20060101); F28C
1/04 (20060101); F28C 1/00 (20060101); B01f
003/04 () |
Field of
Search: |
;261/79A,DIG.11,108-113,24,30 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Miles; Tim R.
Claims
I claim:
1. In a mechanical-draft liquid-cooling tower having an upright
axis, the combination comprising
a. a series of fans spaced about and outwardly from said axis,
b. means defining a series of plenum passages spaced about said
axis and in the direct path of gas displacement by the fans, toward
the tower interior,
c. multiple packing sections spaced about said axis and located in
the spaces between said passages, said sections having inlet
exposure to the passages and outlets communicating with the tower
interior,
d. said means including generally upright partitions to direct the
fan-displaced gas into said packing sections after reception of the
gas in said passages, and with directional flow components angled
from said axis so that the gas upon exiting from said sections
flows in an upward spiral course about said axis within the tower
interior, said partitions extending within the plenum passages,
and
e. means to supply liquid for dispersal within said sections to be
cooled by the gas flow therethrough
2. In a mechanical-draft cooling tower having a generally circular
horizontal cross section and a vertical axis, the combination
comprising,
a. a plurality of upright generally annularly spaced packing
sections having open inlet and outlet sides laterally separated in
a direction generally lengthwise of the tower periphery, the
sections being spaced in said direction and about said axis for
reception of gas therebetween prior and subsequent to gas flow
through the sections between said sides so that the flow through
the sections has substantial components parallel to said direction,
the sections also being radially outwardly spaced from said
direction, the sections also being radially outwardly spaced from
said axis,
b. certain upright partitions located in said spaces between the
sections and extending generally diagonally between the outer
extents of said outlet sides of the sections and the inner extents
of the inlet sides of the sections, thereby to direct the gas to
flow in a spiral course about said vertical axis as the gas passes
through the sections and into the tower interior inwardly of said
sections, there being other partitions located at the radially
inner and outer ends of the sections to block airflow
therethrough,
c. multiple fans mounted to discharge gas under pressure into said
spaces at the inlet sides of the sections for forced-draft flow
through the sections, and
d. means to supply liquid for dispersal within said sections to be
cooled by the gas flow therethrough, said flow in a spiral course
inducing enhanced mixing of the moisture-laden gas so as to
decrease the density thereof thereby to increase the tendency of
the gas to rise in the tower.
3. The combination of claim 2 wherein said fans are mounted at the
tower periphery to direct said discharge gas toward the diagonal
partitions.
4. The combination of claim 3 including fan shroud each extending
with gas-diffusing divergence from the fan peripheries toward the
adjacent packing section.
5. The combination of claim 4 wherein said shrouds are vertically
elongated.
6. The combination of claim 4 wherein the fans are located directly
outwardly of said spaces.
7. The combination of claim 3 including vertically elongated vanes
located in said spaces radially inwardly of the fans and angled to
guide the gas flow into said sections.
8. The combination of claim 1 wherein the fans have blades and are
housed in such relation to said passages that gas may flow past the
fans into said passages when the fans are shut down.
9. The combination of claim 4 including damper means mounted for
movement within at least one shroud for regulating inlet
airflow.
10. In a natural-draft liquid-cooling tower having an upright axis,
the combination comprising
a. a series of fans spaced about and outwardly from said axis,
b. means defining a series of plenum passages spaced about said
axis and in the direct path of gas displacement by the fans, toward
the tower interior,
c. multiple packing sections spaced about said axis and located in
the spaces between said passages, said sections having inlet
exposure to the passages and outlet communicating with the tower
interior,
d. said means including generally upright partitions to direct the
fan-displaced gas into said packing sections after reception of the
gas in said passages, and with directional-flow components angled
from said axis so that the gas upon exiting from said sections
flows in an upward spiral course about said axis within the tower
interior, said partitions extending within the plenum passages,
and
e. means to supply liquid for dispersal within said sections to be
cooled by the gas flow therethrough.
11. In a natural-draft cooling tower having a generally circular
horizontal cross section and a vertical axis, the combination
comprising,
a. a plurality of upright generally annularly spaced packing
sections having open inlet and outlet sides laterally separated in
a direction generally lengthwise of the tower periphery, the
sections being spaced in said direction and about said axis for
reception of gas therebetween prior and subsequent to gas flow
though the sections between said sides to that the flow through the
sections has substantial components parallel to said direction, the
sections also being radially outwardly spaced from said axis,
b. certain upright partitions located in said spaces between the
sections and extending generally diagonally between the outer
extents of said outlet sides of the sections and the inner extents
of the inlet sides of the sections, thereby to direct the gas to
flow in a spiral course about said vertical axis as the gas passes
through the sections and into the tower interior inwardly of said
sections, there being other partitions located at the radially
inner and outer ends of the sections to block airflow
therethrough,
c. multiple fans mounted to discharge gas under pressure into said
spaces at the inlet sides of the sections for forced-draft flow
through the sections, and
d. means to supply liquid for dispersal within said sections to be
cooled by the gas flow therethrough, said flow in a spiral course
inducing enhanced mixing of the moisture-laden gas so as to
decrease the density thereof thereby to increase the tendency of
the gas to rise in the tower.
12. The combination of claim 11 wherein said fans are mounted at
the tower periphery to direct said discharge gas toward the
diagonal partitions.
13. The combination of claim 12 including fan shrouds each
extending with gas-diffusing divergence from the fan peripheries
toward the adjacent packing sections.
14. The combination of claim 13 wherein said shrouds are vertically
elongated.
15. The combination of claim 13 wherein the fans are located
directly outwardly of said spaces.
16. The combination of claim 12 including vertically elongated
vanes located in said spaces radially inwardly of the fans and
angled to guide the gas flow into said sections.
17. The combination of claim 10 wherein the fans have blades and
are housed in such relation to said passages that gas may flow past
the fans into said passages when the fans are shut down.
18. The combination of claim 13 including damper means mounted for
movement within at least one shroud for regulating inlet airflow.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to mechanical and natural draft
water-cooling towers, and more specifically concerns an unusually
advantageous and economical tower construction with substantially
increased water-cooling capacity.
Conventional mechanical and natural draft towers typically employ
grid decking or packing for draining and splashing water in such
dispersed condition as to be cooled by air streams passing
generally horizontally through the packing. The packing decks
normally extend continuously along the side or sides of such a
tower in order to achieve direct inward flow through the packing of
all air passing between the exterior and interior of the tower,
this having been thought to be consistent with most economical
tower construction and mode of operation. For example, it was
thought that continuity of packing extent along the tower sides
achieves maximum "surface" to "area" ratio, the surface referring
to available wetted packing area presented to the entering air, and
area referring to the ground area covered by the tower.
It has been found, however, that the construction and operation of
conventional mechanical-draft towers present certain problems and
lack of desired economies. For example, the length of packed
sections is limited to the length of the tower side, limiting the
water-cooling capacity of the tower below desired level; also,
where fans were located outside the tower, the amount of packing
was reduced by virtue of the location of individual packing
sections adjacent the discharge sides of the fans, resulting in
unequal airflow into the packing sections, a tendency to icing of
the fans in cold weather due to water-droplet splash, and unused
gaps between the packing sections as in U.S. Pat. No. 2,732,190 to
Mart.
BRIEF SUMMARY OF THE INVENTION
It is a major object to provide a mechanical or natural draft tower
construction such as will overcome the above-referred-to problems,
as well as others, while at the same time providing unusual
advantages contributing to reduction in space occupied by a tower
of given capacity, production of spiral flow of air into the tower
interior and a gain in tower-operating economy. Basically, the
invention is embodied in a tower construction that includes a
series of fans spaced about and outwardly of the tower upright
axis; plenum passages spaced about that axis and in the path of gas
displacement by the fans; multiple packing sections spaced about
the axis and located in the spaces between the passages for inlet
exposure to the passages and outlet exposure to the tower interior;
partitions to direct the flow of gas into the packing sections
after gas reception in the passages so that the resultant flow
swirls about the tower axis, and means to supply water (or other
liquid) for dispersal within the sections to be cooled by the gas
flow therethrough. As a result, the passages act to equalize the
fan-discharge flow to the packing sections, and also to isolate the
fans from water splash near the packing, to prevent fan icing.
Also, the structure enables housing of dampers, doors or similar
devices for regulating airflow into the tower as required for
cold-weather operation. The tower shell may be of right circular
cylindrical, hyperboloid of revolution or other geometrically
regular form.
Typically, the tower construction may include certain upright
partitions extending within the spaces between the packing sections
to confine the air to enter the sections at the inlet sides and to
flow laterally within the sections, such partitions for example
extending diagonally between the outer extents of the outlet sides
of the sections and the inner extents of the inlet sides of the
sections to effect the spiral flow. As will be seen, the fans are
typically mounted at the tower periphery outwardly of the spaces
between the packing sections to direct airflow toward the diagonal
partitions. Further, the tower construction may include other
partitions covering the outermost and innermost extents of the
packed sections.
Additional objects and advantages of the invention include the
provision of fan shrouds extending with gas-directing diffusing
divergence from the fan peripheries toward adjacent packing
sections; the provision of packing sections circularly arranged
about a vertical central axis with section elongation generally
radially; the provision of vanes in the passages or spaces between
the packing sections and angled to guide the fan-displaced gas flow
into the packing sections; the provision for inlet flow of air to
the plenum passages in bypassing relation to the fans when the
latter are shut down, to enable natural-draft mode of tower
operation; the provision of water-supply means including a water
basin overlying the section and spaces therebetween, the basin
having dispersal openings located only over the sections; the
provision of means including piping having water outlets directed
to discharge water into the basin to flow therealong and over the
sections and spaces therebetween; and the provision of a basin
underlying such spaces to receive water splashing into the spaces
from the packing sections. Conventional natural-draft cooling
tower, usually of hyperboloidal shape depend largely upon the
lesser density of the moisture-laden interior air than ambient air
to create the draft or air movement. During ambient atmospheric
conditions unfavorable to the creation of sufficient draft for
desired cooling performance; the present invention on the other
hand provides auxiliary fans to create the needed air movement
(quantity). In a similar manner, the addition of fans can reduce
the design size of the cooling tower where available site area is
limited.
These and other objects and advantages of the invention, as well as
the details of illustrative embodiments, will be more fully
understood from the following specification and drawings, in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational showing of one form of mechanical-draft
tower incorporating the invention;
FIG. 2 is a fragmentary plan view of a portion of the FIG. 1 tower,
and partly broken away to show interior construction;
FIG. 3 is an enlarged elevation taken in section on line 3--3 of
FIG. 2;
FIG. 4 is an enlarged elevation taken on line 4--4 of FIG. 2;
FIG. 5 is an enlarged elevation taken on line 5--5 of FIG. 2;
FIG. 6 is an enlarged elevation taken on line 6--6 of FIG. 2;
FIG. 7 is a schematic plan view of a modified form of the
invention; and
FIG. 8 is another schematic plan view of a further modified form of
the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIGS. 1-6, the illustrated water-cooling tower
10 is of mechanical-draft type, wherein air is displaced
horizontally into the lower interior of the tower and rises in the
stack 11 of vertical cylindrical shape and defining a central axis
10a. The stack has modular panel construction, as shown, and is
circular in horizontal planes as is the annular lower portion 12 of
the tower. While airflow to cool dispersed water is described, it
will be understood that gas flow to cool liquid is comprehended
within the scope of the invention.
Included in the tower is a plurality of water-receiving packing
sections having inlet and outlet sides laterally separated in a
direction generally lengthwise or circumferentially of the tower
horizontal periphery. As seen in FIG. 2, the sections 13 are
typically rectangular in plan view with inlet and outlet sides 13a
and 13b separated in the circumferential direction. Further, the
sections 13 are circularly arranged about the vertical central axis
10a of the tower, with spacing therebetween indicated at 14 for
reception of air between the sections. Air displaced into these
spaces, or plenum passages 14a then turns to flow through the
sections 13 between sides 13a and 13b, and is subsequently received
in spaces 14b for exit flow to the tower interior 100. Arrows 15
designate the general flow path. As is clear from FIG. 2, the flow
through the sections 13 has a substantial component 15a concentric
with the (circumferential) direction of the tower horizontal
periphery, and the resultant flow into the tower interior and about
axis 10a produces a swirl effect. The latter upward spiral course
of the positive flow induces enhanced mixing of the moisture-laden
air or gas, so as to decrease the density thereof in order to
increase the tendency of the air to rise in the tower. The airflow
may typically approach a turbulent-flow state, permitting increased
air-water contact with consequent raising of the wet bulb
temperature of the exit air, thereby improving the water-cooling
performance.
Certain partitions or control baffles extend within the plenum
passages 14 to direct the air to enter the sections 13 at their
inlet sides, to flow laterally therein as described. For example,
vertical partitions 16 may be provided to extend diagonally between
the outer extents 17 of the outlet sides 13b of the sections 13 and
the inner extents 18 of the inlet sides 13a of the sections.
Further, other vertical partitions 19 and 20 are provided to cover
the outermost and innermost extents of the sections 13. Such
partitions may extend throughout the vertical heights of the
sections 13 to block airflow through those inner and outer extents
or ends.
Typically, the like sections 13 are radially horizontally elongated
and the overall radial dimension of the section multiplied by the
number of such sections substantially exceeds the boundary
dimension (as for example circumference of tower lower portion 12)
defined by the outer extents of the sections. Accordingly, a
substantially higher than normal ratio of "surface" to "area" is
achieved, these terms having been previously defined.
Extending the description to FIGS. 5 and 6 fans 30 are spaced in
circular series about axis 10a and radially outwardly therefrom,
the fans also being spaced outwardly of the plenum passages 14a and
oriented to positively displace air into those spaces when the fans
are rotated by motors 31. Accordingly, the fans are kept well away
from the sections 13 to prevent icing of the blades due to water
splash in cold weather. Also, flow of air into the sections is
equalized by the plenum passages. In this regard, the fans have
blades 32 and may be housed in such relation to passages 14a that
air may freely flow past the fans and into those passages when the
fans are shut down, providing an auxiliary natural-draft mode of
tower operation as may be desirable or effective under certain
weather conditions. For example, the spaces 33 between the blades
may pass such airflow, or alternatively the fan housing may provide
for such bypass flow. The fan motors 31 may be supported on stands
34 having legs 34a and a crosspiece 34b, as shown.
Housing of the fans 30 may be effected by means of shrouds 35
having venturi shape, forming throats 36 receiving the fans and
diffuser sections 37 to expand the flow to the full vertical flow
area of the plenum chambers. The shrouds may, for this purpose be
vertically elongated as seen in FIG. 5, and extend with divergence
to tops and bottoms 38 and 39 of the passage openings, and to the
vertical sides 40 and 41 thereof.
FIG. 7 illustrates the use of additional flow guides such as vanes
44 in passages 14a, and angled to direct the fan-discharge flow
uniformly into the packing sections. Dampers may be used to
regulate the inlet airflow, as during cold-weather operations. See,
for example, dampers 75 movable in shroud 35 in FIG. 8, as by
pivoting at 76.
Referring back to FIGS. 1- 4, means is provided to supply liquid,
as for example water, for distribution within the sections in order
to be cooled by airflow through the latter, the water typically
falling in dispersed drops which splash and film on the decking
surfaces or slats. Many different types of decking or fill may be
used, FIG. 4 indicating a closely packed section 13 of such fill as
inclined downwardly and in the direction 15 of airflow through the
fill, water particles tending to fall in the packing with
corresponding angularity from vertical. Tower structure supporting
the fill includes columns 55, ties 56 and bracing 57. An upright
drift eliminator 58 is spaced close to the outlet side 13b of the
packing for eliminating drift particles form the exit air
stream.
The water supply means illustrated in the drawings includes a hot
water basin 60 overlying the packing sections 13 and the spaces 14a
and 14b therebetween. As seen in FIG. 3, hot water may be pumped
from a concrete supply conduit 61 upwardly within a riser 62 to a
flume or piping 63 extending transversely and inwardly across the
basin 60. The latter has multiple outlets 64, individually valve
controlled at 65, directed to discharge water into the basin for
open-channel flow therealong in the length direction of the basin.
The basin has intermittent groups 66 of distribution openings 67
located lengthwise thereof, for dispersing water into and onto the
decking or packing sections 13; also the basin over the spaces 14
between sections 13 is free of such holes so that water does not
drain from the basin into the interiors of those air spaces. On the
other hand, any water splashing from the packing into the spaces 14
falls into the collection basin 69 at the bottom of the tower, and
no louvers are needed to intercept such splash since spaces 14 are
within the tower.
To complete the description, an access walkway is shown at 71 over
the piping 63; walkway 72 extends along and at the inner side of
the basin 60.
* * * * *