Note: Descriptions are shown in the official language in which they were submitted.
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163\8~C~55
BAC~GROUND OF THE INVENTION
Field of the Invention
The invention relates to ralling film heat exchangers
and more partiFularly to plate-type falling film condensers.
~iscussion of the Prior Art
Plate-type falling film heat exchangers are highly
e~fective and are widely used in various industrles. Heat
exchangers of this type have been disclosed in United States
Patents Nos. 3,332,469; 3,3Sl,ll9; 3,366,158 and 3,371,709.
Heat exchange elements made up of pairs of plates secured to-
gether around their edges and having opposed dimples to streng-
, . ~ . .
then the element against deformation are described in UnitedStates Patent No. 3,512,239 which discloses a method o~ making
such elements.
Falling film heat exchangers are used as evaporators
to ~aporize liquid flowing as a ~ilm or as condensers to liquiy
steam or other vapo~ by the transfer of hea~ therefrom to a
falling liquid film. In an evaporator the heating of the liquid
is the desired result. In a condenser the heating of the li~uid
is an unavoidable con~equence of the transfer of heat from the
condensing vapor. The heating of the coolant liquid in conden-
.
sers an,d the consequent loss of its ability to cool has been
tolerated in the past.
.
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108~055
SUMM~RY OF THE I~VENTION
The present invention is directed to improving theper~ormance of falling film condensers by providing means for
cooling the flowing film of liquid. While the falling film is
accepting heat transferred frbm the vapor being condensed with-
in a heat exchange element, the liquid is itsel~ evaporatively
cooled ,by the flow of cooling air past the outer surfa~e o~ the
liquid. Thus the falling film of liquid acts as a heat exchange
medium for ~he vapor being condensed, and ~he air flowing past
the alli~g film acts as a heat exchange medium to cool the
li~uid,
A plurality o spaced parallel heat e~change elements
are arranged within a housing. Each heat exchange e}ement is
formed of a pair of'spaced, flat plates joined at their peri- -
. .
pheries. The,heat exchange elements have top openings connec-
ted to a header conduit for the entry or exit of vapor and
.
, ha~e bottom openings connected to a pipe for discharge of con- '
densate. In a modified embodiment of the inven~ion, the hea~ -'
exchange elemen~s are arranged radially; that is upright heat
, exchange elements extend out~Jard like spokes of a wheel.
, ~n the parallel plate arrangement, caoling liquid
enters the housing through a pipe which leads to an overflow
. ~
:~ box within a distribution box spaced above the heat exchange
elemen~s. ~en liquld fills the box it overflows onto a perfor-
ated pla~e which distributes the liquid evenly over the hea~
,'' exchanger elements to form the downward running film on the
element surfaces~ An outlet for the liquid is provided at the
lower end of the housing or casing.
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~08~C)55
Near the bottom of the housing there can be a port
for the admission of cooling air, which encounters the coolant
liquid as the liguid falls as a shower from the lower ends of
the heat exchange elements, thereby cooling the liquid. The
air then will pass upward between the heat exchange elements
in countercurrent 10w to the coolant liquid, and the warmer
saturated air will leave the housing at a poin~ above the tops
of the heat exchange elements.
Alternatively, the coolant air ca~ be introduced
~hrough the sides of the housing, either near the bot~om or
near the top to flow countercurrently ox concurrently with the
coolan~ l~quid.
Non-condensed vapor, including noncondensible gases,
can be vented from the inerior spaces o~ the heat exchange
elements along with the aondensate, or se~arately. If the gases
.
are to be vented along with the condensate, the vapor to ~e con-
densed is introduced thxough an upper header conduit. If the
vent ~ases are to be separated from the condensate, the vapor
to be condensed is admitted to the interior spaces of the heat-
ing elements through a bottom header which connects to the
botttoms o~ the elements, or near their bottoms, to pass upward
in countercurrent flow to the coolant liquid, and the non-conden-
sed gases are vented through a header near the element tops.
It is contemplated that ~he most common use of the
,
sys~em of the in~ention will be in the condensation of s~eam,
using water as the coolant liquid and air as the coolant for the
water, but clearly other gases and liquids can be condensed and
used as coolants. When steam contains noxious constituents, the
separate venting o~ non-condensed gases containlng such noxious
substances pçrmits recovexy o~ cleaner discharged condensate and
facilitates su~sequent treatement o~ the vent gases.
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~L08~0~iS
As in the case o the parallel heat exchange elements,
the radial arrangement of heat exchange elements permits flow
of the vapor, coolant liquid, and cooling air in any permutation
of countercurrent and concurrent flows, though it is contemplat-
ed that the coolant liquid will always flow downward over the
heat exchange surfaces of the elements as a falling film.
In some applications of the invention it is desirable
to employ a fan to force the flow of cooling air pa.t the heat
exchange elements in contact with the coolan~ liquicl flowing
down the heat excha~ge surfaces.
Advantageous arrangements for the distribution o
coolant liquid to ~all as a thin film down the heat exchange
element suraces in condensers according to ~he invention are
dPscribed as being of a pipe or ~lat perorated plate-type.
These and othèr.applications and advantages of the
system of the present invention will be more ully unders~ood
from the following detailed description of preferred embodi-
ments, especially when that description is read with reference
to the accompanying drawing.
.
~ Brief DescriPtion of the Drawin~
. - ,
In the drawing, in which like reference characters -
indicate like parts throughout:
Fig. 1 shows a side cut away view of a condenser
system according to the invention with a bot~om side air inlet,
bottom s-ide vapor inlet and top side air outlet.
Fig. 2 is an end cu~ away view taken pexpendicular to
the view of the condenser of Fig. I~
.
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~0~055
Fig. 3 is a view similar to that of Fig. l of a
condenser system like that of Figs. 1 and 2 except that the
side air inlet is located above the bottoms of the heat exchange
elements.
Fig. 4 is an end cut away view of the system of
Fig. 3 taken perpendicular to the view of Fig. 3.
Fig. S is an isometric view of part ~ the system
according to any one of Figs. ~-4 with some parts broken away
to show interna} struc$ure.
Fig.-6 is a side cut away view of a condenser sy-~tem
according to ~he invention with a cooling air exit at ~he top
of the ~ys~am and a pipe dis~ribu~ion arrangement ~or coolant
li~uid.
Fig. 7 is an end cut away view o the system o Fig. 6
taken perpendicular to the ~iew of Fig. 6.
Fig. 8 is an isometric view of part of the system of
Figs. 6 and 7 with the housing o~itted.
Fig. 9 is a side cut away view o a condenser system
with heat exchange elements arranged radially and having a top
side vapor inlet and a bottom header for condensate and vent
gases which are led out respectively at the bottom and top o~ -
the system.
Fig. lO is a top view o~ the radial sys~em of Fig. 9.
Fig. 11 is a side cut away view of a radial condenser
system with a perforated plate distribution arrangement for
coolant liquid and a bottom side vapor inlet arrangement.
Fig. 12 is a detail view showing a pipe system of
coolant liquid distribution for exit o~ cooling air at the top
of the system.
.
-- 6 --
108~1055
Fig. 13 is a detail view of a per~orated plate system
o~ distribution of coolant li~uid for use in systems according
to the invention wherein air exits at the side of the system.
DETAILED DESCRIPTION OF PREFERRED E~ODI~IENTS
~ . .
The several figures of the drawing illustrate pre-
sently preferred embodimen~s of a pla~e heat exchanger o~ the
falli~g film type particularly effective for the condensing of
steam.. Arrows in the drawing figures show inlets fo~ steam.and
cooling air and cooling water as well as outlet~ for vent gases,
condensa~e and water. Thus in Figs. 1 and 2, steam to be con-
den~ed enters at the lower part o~ the system, and cooling air
also ls admitted at the lower part, whereas vent gases and air
exit near the top and condensate is withdrawn ~rom the bottom
part o the system~ The arrangement of Figsl. 6 and 7 difers
.in that steam to be condensed enters near the top of the system
and condensate and ~ent gases are drawn off ~ogether near the
.
bctttom; that i9, steam and cooling water are in parallel flow.
Each.~exsion of the system has its own advantages. The term
"steam" as used throughout this discussion is u.sed generally as
a synonym for the word "vapor", but it should be understood that
vapor other than water ~apor could be condensed in accordance
with the invention.
Referring now more particularly to the embodimen~
illu~trated in Figs. 1 and 2 it will be seen that the condenser
apparatus generally designated 10 comprises a plurality of
spaced,.parallel vertically oriented heat exchange elements 11,
cach o~ which elements is composed of a pair of spaced parallel
broad plates 12 secured to~ether around the. p~ate peripneries as
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by welding or other means to form enclos~d spaces within the
elements 11. The heating elements ll are enclosed in a casing
generally designated 14, having side walls 15 and end walls 16.
The heat exchange elements 11 can be of the type
described in my prior U. S. pa~ent No. 3,512,239, which dis-
closes a method of manufacturing such elements.
The heat exchange elements ll occupy the central por-
tion of the space within the casing 14. Above the heat ~xchange
elements 11 are means for introducing cooling water (or other
cooling liquid) to flow down the ver~ical surfaces of the plates
12 as a thin film. For this purpose there is a per~'orated tray
18 within the upper portion of the casing, an open-topped box
19 ~paced abov~ the tray 18 and a water inlet pipe 20 passing
~hrough the casing wall 16 for delivery of cooling water.
~ he co~ling water is ed to the box 19 and over~lows
~ . . . ................................ .
out o the open top of the box l9 to distribute water to the
perorated tray 18 more evenly than if the water simply poured
out of the pipe 20 on to the tray 18. The water then 1aws
through the perfora~ed tray to distribute i~self over the sur-
faces ~ the plates 12 and runs down the plates 12 as a thin
fiXm under the influence of gravity~ The water falls from the
lower ends of the heat exchange elements ll as a shower. The
lowest part of the casing 14 has inwardly and d~wnwardly curved
walls 23 to collect the cooling water and ending at an outlet
nozzle 24 for exit of ~he used water.
~ s shown in Fig. 1 there is an inlPt 25 for cooling
air-through ~he curved bottom wall 23 of the casing 14. Upon
entry the cooling air passes ~hrough the showe~ of water falling
from the element 11 and then passes upwards between the elements
ll in countercurrent flow to the direc~ion of 10w of the fall-
,
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-- '` 1 1)8~1~SS
.
ing water film. Of course the elements 11 are spaced apart by
a sufficient distance for free flow of the water film and cool-
ing air. Having traversed the vertical length of the elements
11, the cooling air, carrying some evaporated water, exits.
through.the conduit 26 that passes through the casing wall 16
below the water distribution tray 18 near.the top~ends of the
elements ll.
Having described the casing 14 outside the heat ex-
change elements 11, the flow in the.interibr spaces of ~he
elements ll, where condensation occurs, will be considered.
In the embodim,ent o.f Figs. 1 and 2, steam enters the
interior o~ the heat exchange.elements 11 at the bottom o~ each
element 11, through a bot~om header generally.de~ignat'ed by the
reference numeral 27 on ~he opposite side o the casing 14 from
the air i~let 25~ The term "side"'is used in this description
and in the claims to mean the side walls 15 specifically and
also more generally to mean.all o~ the vertlcal wal,ls lS and.l6 .
o~ the casing as dist~nguished from the bottom or top-o the
'system., This bottom header 27 is fed with steam by a pipe 28
and distributea the steam ~hrough a series o~'slot-like openings
29 to the interior spaces o~ the heat exchange elements 11 as
shown ~est in Fig. 5, showing how the~e is a g~nerally Uee-shaped.
opening at the lower edge of each element 11 where the plates 12 '
thereo~ are not sealed together as they are elsewhere around
,
,; their peripheries. The elements 11 have simi~lar opened edge por-
,, tions at 30 at their upper corners, opening on to an upper header
. .
,~ 31 leading to ~h.e vent exhaust conduît 32. Steam accordingly
., travels upwards in the in~erior spaces formed wi.thi.n the elements
~ ~ 11. .
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1C~8~55
The header 31 can be diagonally opposite from the
location of the header 27, that i~, these headers could open
on to diagonally opposite corners of the elements 11, instead
of being on the same side of the elemen1:s 11 as shown in Figs.
1 and 2.
The hot steam, rising within the elements 11, is
condansed (or cooled and condensed if superheated? by heat
exchange through the plates 12 with the cooling water flowing ;
down the outer surfaces of the plates 12. As the steam con-
denses on the inner surfaces of the plates 12, condensate runs
,
down those ~urfaces. There is, of course, su~ficient open space
between the opposed inner plate surfaces to allow upward passaae
of steam whil~ the condensate flows downward.
. Vapor, plus some non-condensible gases that entered
: .. with the steam, are discharged through the upper header 31
., , - .
and exhaust conduit 32 for such further treatment as may be
,
necessary ox desira~le. The condensate is removed ~rom the.
bottoms of the elements 11.
The tran~verse bottom header 27 also sexves as a
drainage pipe for withdrawal o~ the condensate and is shown to
ha~e a portion extending below the bottoms of the elements 11.
For condensate drainage the header 27 is connected to an up-
standing pipe section.35 that extends downward away from the `-~
casing 14 as shown in Figs. 1 a~d 5. The condensate exits to
.the header 27 throug~ ~he steam entry slots 29.
It will be understood that the heat los~ by the steam
in the condensation thereof is gained by the water of the fall- -
ing film on the outer surfaces of the pla~es 12. Some water
~,
. will evaporate to be carried off through the conduit 26. Thus
; the air entering at the lower paxt of the h~using serves to cool
.,
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-- 10 -- .
the water e~fectively, and to increase the ability of the water
to cool and condense steam within the e:Lements 11. The water
temperature will vary along the height of the plates 12 a~d
will be related to the humidity of the cooling air. Thus the
water will be cooler at the bottom of the elements 11 when there
is a bottom air inlet as in Figs. 1 and 2, since the air near
the top o~ the elements 11 will ~e almost saturated in such a
system.
The condenser system shown in Figs. 3 and i is basic-
ally similar to ~hat shown in Figs. 1 and 2, and indeed the
illustration of Fig. 5 can ~e taken as a partial isometric view
o the embodiment of Figs. 1 and 2 or Figs. 3 and 4. The only
di~eren~e between the embodiment o Figs. 3 and 4 and that of
Figs. 1 and 2 is that the air inlet duct 25a of ~he embodiment
of ~igs. 3 and 4 is adjacent the lower ends of the elements 11
rather than below the ends of the elements 11, reducing the
overall height of the condenser and accordingly requiring less
energy ~o~ pumping water to the top of the system. In the
arrangement of Figs. 3 and 4 the air entering at 25a does not
meet a spray of cooling water as it does in Figs. 1 and 2, so
there is some 1QSS in heat transfer ability, which can be com-
pensated by using more heat exchange elements 11.
The isometric illustration of Fig. 5 shows that the
bottom header 27 is large enough to permit counter flow of
steam entering through the nozzle 28 and condensate exiting
~rom the interior spaces of the elements 11 through the steam
entry openings 29 to leave the system via the drain pipe 35.
Fig. 5 also shows the cooling water distribution system in
somewhat greater detail than the preceding figuxes. It can be
seen that the flat distributlon tray 18 has a plurality of
.
-- 11 --
108~55
holes 40 arranged in parallel lines above the centerlines of
the heat exchange elements ll. The holes 40 are shown as cir-
cular, and can be formed by drilling, but rectangular holes
also work well, are less sensitive to misalignment and can be
pu~ched inexpensively with standard dies. It will also be
seen that the overflow box l9 preferably has cutou~s 41 in i~s
4pstanding walls for distribution of water to the holes 40
when the water from the pipe 20 overflows ~hrough the cutouts
41.
The condenser system generally desig~ated 50 in Fig~.
6 and 7 of the drawings differs signi~icantly from the system
of Figs. 1-5 in that heated cooling air exits at the top of the
sys~em rather than through the side as in Figs. 1-4~ The system
of Figs. 6 and 7 has a casing 54 with generally vertical walls
5~ and 56 and a curved bottom wall area 53 for leading used
, . .
cooling water to an outlet nozæle 54, similar to equivalent
parts of the system o Figs. 1-5. Unlike the embodiment of
Figs. l-S, however, steam is not admitted at the bottom, but
rather near the to~ of the apparatus, ~o flow generally downward
while being condensed.
. As show.n in Figs. 5 and 6, cooling air is ~ed into ~he
system through an opening 57 which can be alongside the lower
.
ends of heat exchange elemen~s 51 like the opening 25a of Fig. 3
or below the bottoms. of the heat exchange elements 51 as in the
~mbodiment af Fig. l.to take advantage of the cooling effect of
passage of the air through a spray of water falling from the
heat exchange elements 51.
The hea~ exchange elements 51 of the embodiment of
Figs. 6 and 7 are generally similar to ~he elemen~s ll of Figs.
1-5, being formed of pairs of plates joined about their peri-
pheries to pro~ide an enclosed space for condensa~.ic~n of s~eam
.
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1~8V05S
within the elements 51 and exterior surfaces for the flow of
coolant liquid as a falling film. However, the only opening
near the bottom of each element 51 is an opening on to a
header 58 for the escape of vent gases and condensate through
the header 58 to a vent nozzle 59 and a condensate drain pipe
60 respectively as shown also in Fig. 8.
The feed of steam to be condensed to the interiors
of the heat exchange elements 51 is by way of a header 62
connected tG steam.inlet pipe 63. The header 62 and its open-
ings into the elements 51 are.similar in structure to the
header 27 described in conjunctian with the embadiment o~ Figs.
1-5, except that the header 62 is positioned a~ the upper ends
of the elements 51 to feed in steam only at the top of each
element Sl.
Thus, in the embodiment of Figs. 6 and 7, the steam
passes downward through the elements Sl, flowing in the same
direction as the water film on the outside of each element 51.
As in the embodiment previously described, the exchange of
heat from the steam to the thin film of water condenses steam
inside each element Sl, and the condensate collects on the
inner plate surfaces of the elements Sl. The condensate runs
down inside the elements 51 and exits at the bottom through
the hcader 58 and pipe 60. In this case, however, the noncon-
densible substances and any uncondensed steam also exit t~rough
the header 58, passing out.through the vent conduit 59.
The system of Figs. 6 and 7 is similar to the other
embodiments praviously described in that the coolin~ effect of
air is employed. Externally of the elements 51 or 11 the same
processes occur in both embodiments of this invention. The
air introduced through the bottom wall 53 of the casing at 57
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~08~3~55
evaporatively cools the water it encounters in moving upwards
in countercurrent flow to the falling water. When the air
stream leaves the system through the system it will have in- -
creased the cooling capa~ility of the water by itself cooling
the water.
Since the arrangement of Figs. 6 and 7 provides or
the exit of cooling air through the ~op of the apparatus ra~her
than at the side as in the previously discussed embodiments,
- the perforated plate system of distribution of cooling wa~er is
not employed, since such an arrangement would not permit ~ree
passage of the air. ~n the ar~angement o Figs. 6 and 7, in-
stead of a perforated plate, a series of perforated pipes 65
overlie ~he upper edges o the heat e~change elements 51~ Cool-
ing water enters through a manifold 66 whence it is evenly dis-
tribu~ed to all of the pipes 65. The cooling water then runs
;;i through spaced holes 67 of the pipes 65 to form a film running
down the exterior surfaces of the elemen~s 51. Using this method
~or dis~ribution of coolant liquid, air passes freely out of the
top o~ the condenser system 50. A slow speed, high volume fan
68 having a hub 69, blades 70 and driven by an electric motor 71
connected by a drive shaft 72 to a gear box 73 is prefera~ly
employed to pull air upward through and out of the condenser
system. The top o the condenser system 50 is preferably formed
as an upwardly widening diffusor outlet at 74 to enhance air
J~ ~low.
. :
The drive motor 71 is shown outside the difusor out-
let 74 to protect the~motor from moisture carried by the exhaust-
ed air, which has evaporated some of the wa~er it has cooled in
passing up through the condenser.
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~ 3055
It should be noted that in the embodiment of Figs.
6 and 7 the steam inlet is at the side near the upper ends o~
the heat exchange elements 51 for parallel flow of steam and
cooling water instead of the countercurrent flow directions for
steam and water as shown in Figs. 1-5. However, variations on
both embodLments are possible for any permutation of directions
of flow of air, water and steam, provided that the coolant
- water flows downward as a falling film. This flexibility of
the system allows the user to adjust to almost any design re-
quirements while keeping the basic structural elements of the
system essentially unchanged. Thus the steam inlet ~o the in-
teriors of the heat exchange elements can be at the element
sides either a~ their tops or bottoms, or at the bottom edge
o the element, the aix outlet can be at the side nQar the top,
or through the top as in Figs. 6 and 7, or the air can be ~ed
.
downwards through the system parallel to the flow of cooling
.
water to exit at or near the bottom of the condenser. In any
of these arrangements a fan aan be used to force the flow of
air through the system if de~ired.
i . . .
Fig. 8, like Fig. 5, shows what can be called an
"element package", that is, a par~ially assembled condenser
system which can be shipped to a user and then installed within
a casin~. The apparatus shown in Fig. 8 i5 basically similar
to what has been discussed in conjunction wi~h Figs. 6 and 7,
except for the location of the motor at 71a, shown in Fig. 8
as mounted on the steam header 62. This is intended to illus-
trate that the motor 71 can be positioned anywhere in the ~lane
of the fan drive shaft 72 for ease of maintenance and to fit
design requirements. It can also be seen that the water dis-
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lQ80~55
tribution manifold 66 is shown to be significantly larger in
cross sectional area than the water di~tribution pipes 65
leading therefrom, to assure a uniform distribution of cooling
water to all of the several pipes 65.
The embodiments of Figs. 9, lV and 11 depart ~rom
the parallel heat exchange element structure-o~ the previously
described embodiments, while individually quite like the
elements 11 and 51 already described, are arranged in a radial
configuration.
Like the embodiment of Figs. 6 and 7, the apparatus
shown in Figs. 9 and 10 provides for the exit o~ cooling air
fro~ the top o~ the system. The conaenser of Fig~. 9 and 10,
generally designated by the reference numeral 80, has a plural-
ity of heat exchange elements 81 formed by pairs of rectangular
plates joined togethér around their peripheries like the heat
ex~ange elements 11 and 51 already described. The casing 82
of the condenser system 80 i9 generally cylindrical, with a
downwardly concave disk like floor 83 having a central drain 84
for the discharge of coolant wa~er which has passed over ~he
heat exchange element 81 as a ~alling ~ilm.
Wi~hin the casinq 8~, the upright heat exchange
elements 81 are in a radially extending array, equally arcuately
spaced lik~ the spokes of a wheel.
.
Steam is introduced into the interior spaces within
i the heat exchange elements 81 through a steam inlet 85 connected
. .
to a steam header 86 extending around the circumference o~ the
casing 82 near the tops o~ the heat exchange element 81, which
have openings on to the header 86 like the steam inlet openings
29 shown in Fig. 5. The steam condensed within the heat exchange
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~8~055
.
elements 81 by heat transfer to the cooling water, and the . vent gases not condensed, exit from the ~elements 81 into a
common central chamber 87 opening on to the lower inside edges
of the elements 81. A condensate drain pipe 89 leads from the
center of the chamber 81 downward and out of the casing 8~ as
shown at 90 in Fig. 9. An upwardly extending conduit 91 leads ...
vent gases from the central chamber 87 to a point above the
tops of the elements 81 and thence generally horizontally out
of the casing to a vent outlet 92. The vent outlet conduit ~1,
92 does pass across the area through which cooling ai.r flows up-
ward, bUt because of the,relatively small dimensions of the con-
duit, the interference with air fLow is minimal.
The cooling air enters fro~ the sides below the array
of heat exchange elements 81 as shown by ~he openings 93 to
, contact the water streaming off the heat exchange surfaces 81 :
.in a manner similar to that of the embodimen~ of Figs. 1 and 2,
and the air then passes upward, cooling the falling water film
, by evaporati.on. A large ~an 95 operating at low speed with high
volume action draws the cooling air upward to a space enclosed
by the generally slightly conicaL diffusor wall 96. The fan 95
hag a hub 97 and blades 98 as shown in ~igs. 9 and 10.
Separating the central area o~ the condenser system
80 fxom the area through which air and wa~er flow between and over
: the heat exchange elements is an upstanding cylindrical wall 99
which prevents the cooling air from entering the central part of
the system, so that the cooling air must flow between the heat
exchange.elements 81.
Since the embodiment of Figs. 9 and 10 has air exiting
;~ at the top, the distribution system for cooling water must not: '
. .
- 17 -
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~080055
block air flow. Accordingly, coolant water enters through an
inlet 101 to a circular coolant water manifold 102 located in-
wardly at the upper end of the barrier wall 99, and the water
is distributed to the surfaces of the heat exchange elements
by a plurality of perforated pipes 103, one pipe 103 being
arranged above the upper edge of each element 81 in a manner
.
generally similar to that illustratea in the parallel plate
arrangement of Figs. Ç and 7.
- - After ~lowing over the elements 81 the cooling water
falls as a spray into the collectiQn area defined by the bottom
wall 83, meeting the incoming air. It will be notecl that the
.
condensate drain pipe 89 is exposed to the incoming cooling air,
which ~urther cools the condensate therein. If desired, the
pipe 89 could be ~inned to enhance cooling of the aondensate. '
It will be noted that in the radial arrangement of
Figs. 9 and 10, the distance between adjacent heat exchange
elements 81 increases with the distance from ~he vertical
i
centerline o~ the condenser 80 because the elements 81 are
themselves of substantially uniform thickness throughout their
widths ~rom inner to outer edge. ~owever, the diferencè in
air velocity between the inner and outer edges o~ the heat
exchange elements is nct signi~icant in a large condenser
system according to this emdodiment of the invention.
.
Like the system of Figs. 9 and 10,-the embodiment of
Fig. 11 has a radial array of heat exchange elements 111 formed
by pairs of rectangular plates joined around theix edge~. The
system of Fig. 11 has a cylindrical outer casing 112, a dish-
like water collecting bottom wall 113 and a coolant water dis-
charge outlet 114. Unlike the radial arrangement o~ Figs. 9
and 10, the condenser o Fig. 11 has a bottom si.de stream inlet
arrangement, with steam to be condensed entering ~:hrough the
~.
- 18 -
~08~(~55
inlet 115 and passing through an annular bot~om steam header
116 to the interiors of the plurality of heat exchange elements
111 in a manner similar to that shown in Figs. 1-5. Condensate
formed within the heat exchange elements 111 exits to the steam
inlet header 116 and is discharged through pipe~ 117. Noncon-
densible and vent gases leave the interior spaces of the heat
exchange elements 111 through a circumferential header 118
which communicates with openings at the upper outside edgPs of
the elements 111 like the header 31 of Fig. S.
The cooLing water distribution sy~tem of the embodiment
of Fig. 11 is similar to that of Figs. 1-5 adapted to ~he radial
arrangement of heat exchange elements 111. There is an annular
,
per~orated plate lL9 arranged above the top~ of the heat exchange
elements lLl to deliver a uniorm flow o water ~o the element~
surfaces through per~oration~ 120. Water is distribu~ed to the
perorated plate from a ring-shaped overflow box 121 generally
similax to the over~low box 19 of the embodime~ts of Figs. 1-5
except that the box 121 has an annular form. Water is fed to
; the overflow box 12L through inlet nozzles 122.
The cooling water ouerflows cutouts ~not shown in Fig.
11) o~ the box 121 on to the perforated plate 119 whence it
~alls out holes 120 aligned with the heat exchange elements 111.
The cooling water then flows down the ~ull length of the elements
i .
111 and drops in the form of a shower to be collected in the
sump formed by the floor 113 whence it exits through the drain
114.
Cooling air enters through the ducts 125 below the
elements 111 where it encounters the shower o~ water. The air
is then drawn up between the elements 111, cooling the water by
euaporation. An inner cylindrical walL 126 extending upward
.
' 19
.
~8~55
most of the height of the elements 111 ends below the tops of
the eiements 111, allowing the air to ~e drawn radially inward
and upward by the fan 127 as shown by the arrows in the draw-
ing, to be exhausted to the atmosphere through the diffuser 128.
It will be seen that the inner wall 126 encloses a
compartment for a motor 129 that dri~es the fan 127 through
drive shaft 130. Support structure for-the fan 127 is shown at
131. A manhole 132 and ladder 133 allow personnel to enter
within the inner wall 126 for inspection and maintenanca. i-
The radial embodiments of the invention of Figs. 9
can have one or more air inlets, condensate and vent outlets,
etc. It should also be noted tha~, as in the other embodiment
0~ the invention steam can be ed into the heat exchange elements
at or near their bot~oms, through the sides or at the top of the
elements, and air and cooling water can flow concurrently or
. .
countercurrently, although not all of the permutations have been
illustxated in ~he drawings.
Figures 12 and 13 illustrate the two pre~erred types
of water distribution, as well as-details of the heat exchang~r
elements, identified by number 11 in these drawing figures.
~he e~ements 11 are formed of two generally rectangular plates
12 usually of steelj welded together at their edges as shown a~
the top edge, and spo~ welded a~ spaced locations 141, and ~an
be made in accordance with my prior United States patent ~o.
3,512,23g or U.S. patent No. 3,736,783. In Fig. 12, the pipe P,
which could be the pipe 103 of Fig. 9 or 65 of Figs. 6-8 has
spaced holes ~or distributing wa~er fxom the pipe in~erior to-
the top edge L40 of the element 11 whence the water spreads it-
sel evenly to fall as a film. The spaced dimples foxmed by the
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.
spot welds 141 prevent channelling o the water flow down the
plates of the element 11.
In Fig. 13, the perforated distribution plate D has
holes ~or the discharge of cooling watex to the element 11 as
in the embodiments o Figs. 1-5 and 11.
It should also be understood.that the condensate,
vent gases and noncondensibles discharged from the conden~er
can be subjected to further treatment as desired, and the cool-
ing water discharged can be reused.
Numerous variations, modifications and adaptations
of the condensex system ~ccording to the invention, such as, for
example use with other media than air and water, will suggest
themselves to those acquainted with heat exchange technology,
and are considered to be within the spirit and scope o the
invention.
.
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