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United States Patent |
5,695,006
|
Usui
,   et al.
|
December 9, 1997
|
Heat dissipation unit for cross flow type cooling tower and process for
making the same
Abstract
The present invention relates to a heat dissipation unit for cross flow
type cooling tower with which it is possible to prevent the emission of
white vapor without lowering the cooling power of the cooling tower, and
also without requiring troublesome routine operation. In order to
accomplish the above object, the heat dissipation unit of the present
invention comprises filling plates arranged vertically and parallel with
each other so as to form spaces therebetween, each of the filling plates
having uneven surfaces down which water to be cooled flows when water to
be cooled is supplied onto the filling plates, and cowl members disposed
between neighboring filling plates, each of the cowl members including a
pair of side plate portions having upper ends and a roof portion
connecting the upper ends of the side plate portions. The side plate
portions of the cowl members are arranged substantially parallel with the
filling plates so as to form gaps between the filling plates and the side
plate portions of the cowl members.
Inventors:
|
Usui; Masahiro (Chigasaki, JP);
Yamamoto; Shigehira (Hiratsuka, JP);
Goto; Osamu (Ushiku, JP)
|
Assignee:
|
Ishikawajima-Harima Heavy Industries Co., Ltd. (Tokyo, JP)
|
Appl. No.:
|
708717 |
Filed:
|
September 5, 1996 |
Foreign Application Priority Data
Intern'l Class: |
F28C 001/04; F28C 001/16 |
Field of Search: |
165/115,DIG. 163
261/112.1,153,DIG. 11,DIG. 77
29/890.03
|
References Cited
U.S. Patent Documents
3011723 | Dec., 1961 | Van Weele | 239/193.
|
3301401 | Jan., 1967 | Hall | 210/150.
|
4980098 | Dec., 1990 | Connery | 165/115.
|
5505882 | Apr., 1996 | Kato | 261/153.
|
Foreign Patent Documents |
2127990 | Dec., 1971 | DE | 261/112.
|
Primary Examiner: Flanigan; Allen J.
Attorney, Agent or Firm: Fish & Richardson P.C.
Claims
What is claimed is:
1. A heat dissipation unit comprising:
filling plates arranged vertically and parallel with each other so as to
form spaces therebetween, each of said filling plates having uneven
surfaces down which water to be cooled flows when water to be cooled is
supplied onto said filling plates; and
cowl members disposed between neighboring filling plates, each of said cowl
members including a pair of side plate portions having upper ends and a
roof portion connecting said upper ends of said side plate portions;
wherein said side plate portions of said cowl members are arranged
substantially parallel with said filling plates so as to form gaps between
said filling plates and said side plate portions of said cowl members.
2. The heat dissipation unit according to claim 1, wherein at least a part
of each of said cowl members is arranged along upper ends of said filling
plates.
3. The heat dissipation unit according to claim 1, wherein said roof
portion of said cowl member comprises a pair of inclined plate portions
abutted against each other to form an inverted "V" shape.
4. The heat dissipation unit according to claim 1, wherein each side plate
of said cowl member is fixed to said filling plate by means of spacers.
5. The heat dissipation unit according to claim 1, wherein each side plate
of said cowl member has at least a protrusion projecting towards said
filling plate and said protrusion is fixed to said filling plate.
6. The heat dissipation unit according to claim 1, wherein the thickness of
said gap formed between said side plate portions and said filling plate is
in the range of 2-10 mm, and the height of said side plate portion of said
cowl member is in the range of 20-80 mm.
7. A cross flow type cooling tower comprising:
a heat dissipation unit having upper and lower ends;
water supply means for supplying water to be cooled to said upper end of
said heat dissipation unit so as to form water supply areas and water
non-supply areas on said upper end of said heat dissipation unit; and
a water receiver for collecting cooled water flowing down from said lower
end of said heat dissipation unit;
wherein said heat dissipation unit comprises:
filling plates arranged vertically and parallel with each other so as to
make spaces therebetween, each of said filling plates having uneven
surfaces down which water to be cooled flows when water to be cooled is
supplied onto said filling plates; and
cowl members disposed between neighboring filling plates, each of said cowl
members including a pair of side plate portions having upper ends and a
roof portion connecting said upper ends of said side plate portions;
wherein said side plate portions of said cowl members are arranged
substantially parallel with said filling plates so as to form gaps between
said filling plates and said side plate portions of said cowl members.
8. A process for making a heat dissipation unit comprising the steps of:
arranging filling plates in parallel with each other so as to form spaces
therebetween;
folding plates to form cowl members having a pair of side plate portions
and a roof portion connecting said side plate portions to each other;
providing spacing means on an outer surface of each of said side plate
portions of said cowl members; and
inserting said cowl members between said filling plates and fixing said
spacing means to said filling plates so as to form gaps between said
filling plates and said side plate portions of said cowl members.
9. The process according to claim 8, wherein said step of inserting said
cowl members is performed while elastically deforming said cowl members to
reduce the width of the space between said side plate portions so that
said side plate portions move toward said filling plate after said
inserting step.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a heat dissipation unit for a cross flow
type cooling tower and a process for making the heat dissipation unit.
The conventional cross flow type cooling tower has a general tendency to
emit white vapor from the exhaust port thereof in cold weather, and this
white vapor is liable to cause anxiety in the neighboring residents. For
example, the neighboring residents are likely to believe that the white
vapor pollutes the air and to feel an aversion to the white vapor; or they
are likely to mistake the white vapor for smoke from a fire when the vapor
reflects red light from, for example, of neon signs.
Various attempts have been made in the prior art to prevent the emission of
the white vapor from the cross flow type cooling tower. For example,
Japanese Patent Application, First Publication No. 3-75495, discloses a
cross flow type cooling tower comprising an improved heat dissipation
unit. This heat dissipation unit includes a plurality of filling plates
vertically arranged parallel with each other so as to make fixed clearance
between them, and each of the filling plates has uneven surfaces along
which the water to be cooled flows down when the water is sprayed onto the
heat dissipation unit. The upper ends of the gaps formed between the
neighboring filling plates are closed; or, are covered with cowl members
which can be opened, and air passages are formed for emitting only the air
from the heat dissipation unit.
However, because the exclusive air passages are provided, the above heat
dissipation unit has a drawback that the cooling power is lowered in
comparison with conventional ones, and it is necessary to enlarge the size
of the cooling tower to obtain the necessary cooling power. Furthermore,
in the case where the openable cowl members are provided, opening and
closing the cowl members requires a great deal of labor, and makes routine
maintenance troublesome.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a heat dissipation unit
with which it is possible to prevent the emission of white vapor without
lowering the cooling power of the cooling tower, and also without
requiring troublesome routine operation, such as opening and closing
operations for cowl members according to changes in the seasons.
In order to accomplish the above object, the heat dissipation unit of the
present invention comprises: filling plates arranged vertically and
parallel with each other so as to make spaces therebetween, each of the
filling plates having uneven surfaces down which water to be cooled flows
when water to be cooled is supplied onto the filling plates; and cowl
members disposed between neighboring filling plates, each of the cowl
members including a pair of side plate portions having upper ends and a
roof portion connecting the upper ends of the side plate portions; wherein
the side plate portions of the cowl members are arranged substantially
parallel with the filling plates so as to form gaps between the filling
plates and the side plate portions of the cowl members.
According to the heat dissipation unit of the present invention, hot water
to be cooled supplied from above the heat dissipation unit is caught by
the roof portions of the cowl members, the water flows into the gaps
formed between the side plate portions and the filling plates and it flows
down the uneven surfaces of the filling plates. Because the entire amount
of water flows down along the uneven surfaces of the filling plates and
can contact air horizontally flowing through the spaces between the
filling plates, the hot water can be effectively cooled by heat of
vaporization. At the same time, moist air is generated.
In contrast, in the water non-supply area of the heat dissipation unit,
while the air is flowing through passages surrounded by the filling plates
and the cowl members, the air contacts with the dried surfaces of the
filling plates which are heated by the hot water contacting the filling
plates in the water supply area. Therefore, dry air is generated and it is
mixed with the moist air while flowing through the passages, the mixed air
which does not contain supersaturated vapor is emitted from the exhaust
port of the cooling tower without generating white vapor even when the
ambient temperature is low.
The cross flow type cooling tower according to the present invention may
also comprise the above-described heat dissipation unit; a water supply
for supplying water to be cooled to the upper end of the heat dissipation
unit so as to form water supply areas and water non-supply areas on the
upper end of the heat dissipation unit; and a water receiver for
collecting cooled water flowing down from the lower end of the heat
dissipation unit.
It is another object of the present invention to provide a process for
making a heat dissipation unit in which process the manufacturing cost can
be decreased.
In order to accomplish the above object, the process for making a heat
dissipation unit of the present invention comprises the steps of:
arranging filling plates in parallel with each other so as to form spaces
therebetween; bending plates to form cowl members having a pair of side
plate portions and a roof portion connecting the side plate portions to
each other; providing spacing means on an outer surface of each of the
side plate portions of the cowl members; and inserting the cowl members
between the filling plates and fixing the spacing means to the filling
plates so as to form gaps between the filling plates and the side plate
portions of the cowl members.
According to the above process, because the cowl member can be easily made
of a flat plate, it is possible to manufacture the heat dissipation unit
at reduced cost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of a cross flow type cooling tower in which a
heat dissipation unit of the present invention is used.
FIG. 2 is a perspective view of a cowl member of the heat dissipation unit
of the present invention.
FIG. 3 is a cross section of a plate for making the cowl member.
FIG. 4 is a cross section showing a step for forming projections on the
plate.
FIG. 5 is a cross section showing a step for folding the plate to form the
cowl member.
FIG. 6 is a side view showing a step for installing the cowl member on
filling plates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 6, the best mode of the heat dissipation unit and
the cross flow type cooling tower, and the manufacturing method thereof,
according to the embodiment of the present invention, will be explained.
As shown in FIG. 1, the cross flow type cooling tower of this embodiment
comprises a heat dissipation unit A, an upper water tank 3 provided above
the heat dissipation unit A for spraying hot water to be cooled onto the
heat dissipation unit A, and a lower water tank 4 provided below the heat
dissipation unit A for receiving the cooled water failing from the heat
dissipation unit A.
The heat dissipation unit A comprises a plurality of filling plates 1
having a rectangular shape, which are vertically arranged parallel with
each other so as to form a constant space therebetween. Each filling plate
1 has uneven surfaces on both faces, and water to be cooled which is
sprayed from the upper water tank 3 flows along the uneven surfaces.
Between neighboring filling plates 1, cowl members 2 having an inverted
gutter shape are horizontally fixed along the upper and lower ends of the
filling plates 1.
The cowl member 2 consists of a pair of side plate portions 21 having a
long rectangular shape and a roof portion 22 connecting the upper ends of
both side plate portions 21. The side plate portions 21 of the cowl
members 2 are arranged in parallel with the corresponding filling plates 1
so as to form constant gaps between the filling plates 1 and the side
plate portion 21, and these gaps allow passage of water to be cooled and
passage of heated air.
As shown in FIG. 2, a plurality of projections 211 are formed on the outer
surface of the side plate portion 21 at a constant intervals along the
longitudinal direction of the side plate portion 21, and the projections
211 are bonded to the filling plate 1, for example, by means of an
adhesive. Thus, the cowl members 2 are fixed to the filling plates 1 while
forming gaps having a constant thickness between the side plate portions
21 and the filling plates 1. The thickness W of the gap is not restricted
in the present invention, but is preferably in the range of 2-10 mm, and
is more preferably, about 5 mm. The height H of the side plate portion 21
of the cowl member 2 is not restricted in the present invention, but is
preferably determined in the range of 20-80 mm according to the size of
the cooling tower, and is more preferably, about 50 mm.
The roof portion 22 consists of a pair of inclined plate portions 221
abutted against each other to form an overall inverted "V" section so that
the water sprayed from the upper water tank 3 can be dispersed by the roof
portion 22. Considering the dispersing effects of the roof portion 22, the
angle between the two inclined plate portions 221 is preferably in the
range of 100-1800, and more preferably, is about 120.degree..
The process for making the above heat dissipation unit A will be explained
referring to FIGS. 3 and 6. First, a plurality of the filling plates 1 are
arranged vertically and parallel with each other so as to make a constant
space therebetween to form the skeleton of the heat dissipation unit A.
Next, as shown in FIG. 3, flat plates 2a formed from a material having
plasticity, for example, plastic or metal, are prepared. After softening
the plate 2a by heating, the plate 2a is subjected to press forming for
forming the projections 211 as shown in FIG. 4. The method for forming the
projections 211 is not restricted to the press forming, but other forming
method, such as vacuum forming, can be also employed. The shape of the
projection 211 is not limited to a rectangular shape, but can be modified
to other suitable shapes, such as a disc shape or a triangular shape.
The plates 2a on which projections 211 are formed are subjected to bending
in order to form the cowl member 2 using press dies 5 and 6 as shown in
FIG. 5. Each of the press dies 5 and 6 has a press faces having an
inverted "V" section and a horizontal length being identical with or
longer than the cowl member 2, and the width of the press faces is decided
according to the width of the cowl member to be formed. Each plate 2a is
pressed between the two dies 5 and 6, if necessary, after heating, and is
bent to have an inverted "V" section. Furthermore, both ends of the plate
2a, protruding from the dies 5 and 6, are bent until both ends contact
with the side face of the male die 5; thus, it is possible to form the
cowl member 2 having a pair of the side plate portions 21 and a roof
portion 22.
As shown in FIG. 6, when the cowl member 2 is released from the dies 5 and
6, the bending angle of the roof portion 22 will be widened by springing
back. Therefore, if the sectional angle of the press faces of the dies 5
and 6 is 01, which is the sectional angle of the roof portion 22 of the
cowl member 2 installed in the heat dissipation unit A, the sectional
angle of the roof portion 22 will become 02 being larger than 01, and the
distance between both side plate portions 21 will also be widened compared
to the parallel condition. Accordingly, by means of inserting the cowl
member 2 into the space between the filling plates 1 while pushing the
side plate portions 21 toward each other, it is possible to elastically
press the projections 211 against the filling plates 1 after the
insertion. Therefore, only by means of applying adhesive agent between the
projections 211 and the filling plates 1, it is possible to easily bond
the cowl member 2 to the filling plates 1. Furthermore, in the case that
the cowl member 2 is formed by bending the flat plate 2a, the cost for
manufacturing the heat dissipation unit A can be reduced.
The upper water tank 3 comprises a number of spray nozzles on the bottom
thereof and shutters 31 provided on each of the spray nozzles for
controlling the amount of the water to be sprayed by each nozzle. It is
thereby possible to control the area ratio of a water supply area and a
water non-supply area on the upper end face of the heat dissipation unit
A. By controlling the area ratio of a water supply area and a water
non-supply area, it is possible to control the vapor concentration of the
air emitted from the cooling tower so as to prevent the emission of the
white vapor. In general, the water supply area should be decreased in cold
season in which whim vapor can be easily generated, and it should be
increased in warm season.
In the water supply area of the heat dissipation unit A, the hot water to
be cooled sprayed by the nozzles of the water tank 3 is caught by the roof
portions 22 of the cowl members 2, the water flows into the gaps between
the side plate portions 21 and the filling plates 1, and it flows down the
uneven surfaces of the filling plates 1. While the water is flowing down
along the uneven surfaces of the filling plates 1, the water directly
contacts with the air which is horizontally flowing through the spaces
between the filling plates 1, and the hot water is cooled by heat of
vaporization; thus, moist air is generated.
In contrast, in the water non-supply area of the heat dissipation unit A,
while the air is flowing through passages surrounded by the filling plates
1 and the cowl members 2, the air contacts with the dried surfaces of the
filling plates 1 which are heated by the hot water contacting the filling
plates 1 in the water supply area. Therefore, dry air is generated and
will be mixed with the moist air while flowing through the passages, and
the mixed air which does not contain supersaturated steam is emitted from
the exhaust port of the cooling tower without generating white vapor even
in the cold seasons.
In the above embodiment, the cowl members 2 are disposed at the upper and
lower ends of the filling plates 1; however, the present invention is not
restricted to this arrangement. For example, the cowl members 2 can be
installed only at the upper end of the heat dissipation unit A; or they
can be installed at the upper end and middle portion of the heat
dissipation unit A.
Furthermore, instead of the upper water tank 3 shown in FIG. 1, water
sprinkler pipes can be provided above the heat dissipation unit A as a
water supply means. In this construction, it is easy to control the area
ratio of a water supply area and a water non-supply area on the upper end
face of the heat dissipation unit A.
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