US2659580A - Plate heat exchanger - Google Patents

Description

Nov 17 1953 R. P. HYTTE 2,659,580

PLATE HEAT EXCHANGER Filed April 19, 1950 Zwar Aff 1N VEN TOR. faber! ponia/.s [arsson 71yzle Patented Nov. 17, 1953 PLATE HEAT EXCHANGER Robert Pontus Larsson Hytte, Lund, Sweden, as-

signor to Aktiebolaget Separator, Stockholm, Sweden, a corporation of Sweden Application April 19, 1950, Serial No. 156,739

6 Claims.

This invention relates to heat exchangers, and more particularly to an improved plate heat eX- changer of the type having a regenerative section and a holder cell.

In the thermal treatment of milk and other liquids in plate heat exchangers, it is common practice to cause the heated liquid, after pasteurization, to give off heat in the plate apparatus to the in-flowing cold liquid to be treated. For this purpose, the apparatus is provided with a regenerative section in Which the liquid, passing at pasteurizing temperature in counter-current relation to the cold liquid, gives oi heat to the latter.

The centrifugal treatment of milk in dairies is eiiected at a temperature between the initial temperature and the pasteurizing temperature. The milk must therefore be withdrawn from the regenerative section at a point where it has the proper separating temperature and then, after the centrifugal treatment, returned to the regenerative section at the same point of the temperature curve and further heated to pasteurizing temperature. In order to enable withdrawing and returning of the liquid, a so-called coupling plate is used, which is interposed at the liquid Withdrawal and return point of the set of plates constituting the regenerative section. This section is thus divided into two sub-sections, each having its set of plates. A heating or pasteurizing section in the plate apparatus is formed by a third set of plates.

The principal object of the present invention is to simplify the plate apparatus with a view to making it cheaper. This is accomplished by moving the holder cell to the location where the coupling plate is arranged in conventional apparatus and providing it with means by which it can be connected to the inlet and outlet pipes of a centrifuge. In accordance with the invention, the holder cell is thus placed between the two sub-sections of the regenerative section, instead of beyond the regenerative section as has heretofore been common practice.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

Fig. 1 is a diagrammatical View of a plate heat exchange apparatus of the conventional type;

Fig. 2 is a similar view of a plate heat exchange apparatus made according to the invention;

Fig. 3 is a perspective view of the holder cell of the conventional apparatus illustrated in Fig. l; and

- paratus.

Fig. 4 is a perspective view of a holder cell,

made according to the invention.

According to Fig. 1, the liquid to be treatedl enters the plate apparatus at inlet ID, flows through the heating side of a set of plates Ii, and then at I2 into a coupling plate I3, the object of which is to enable Withdrawal of the liquid from the apparatus. Thus, the liquid leaves the coupling plate through an outlet I4, passes through a centrifuge (not shown) and is reintroduced into the coupling plate through an inlet I5. At passage I6 the liquid flows from the coupling plate I3 into a set of plates Il. It then passes along the heating side of plates I'I until it leaves the lset at passage I8. The sets oi plates II and Il together form the so-called regenerative section of the plate apparatus. In this section, heat is transmitted to the inflowing liquid by bringing about a heat exchange with the liquid returning from a pasteurizing zone of the ap- When the centrifugal treatment consists in separating milk into cream and skim milk, only the skim milk is introduced at I5, the cream being heat-treated separately in one or more sets of plates or in other apparatus provided for this purpose. At the side of the set of plates Il, there is a holder cell I9 in the plate apparatus. The liquid from passage I8 iiows through the holder cell in a simple throughflow channel and, at 26, enters the set of plates 2I in which it is heated to pasteurizing temperature, steam or hot water being used as a heating medium in this set. The steam is fed in at inlet 22 and withdrawn at outlet 23, possibly in the form of a condensate, after it has given o heat to the liquid in the set of plates 2|. At outlet 24, the liquid reaches pasteurizing temperature, and it then proceeds through a channel 25 (which is often in the form of a pipe line located outside the apparatus) to the holderl cell I 9, the point of entrance to the cell being at inlet 26. In the cell I9, the liquid generally passes through a zig-zag channel, symbolized by the zig-zag line 27,

and discharges at outlet 28 to the cooling side of the set of plates I'I. Through a channel 29 in the coupling plate I3 it then flows into the set of plates II and, after having passed along the cooling side of this set, leaves the apparatus at outlet 30.

The holder cell I9 is illustrated in Fig. 3. -On its way to the heating section 2|, the liquid flows through the channel I8--20 in the upper lefthand corner. The liquid has not then assumed pasteurizing temperature. From the pipe 25 it enters the holder cell at inlet 26 and flows through the zig-zag channel 21, formed by stag- According to: Figs. 2 and 4, the in-flowing liquid passes .ifi-cin..

the inlet I along the heating side of the set 'of plates to an orifice I or inlet ofzthetholdersoell; 3|, whence it proceeds through. aA duct orwoutletj:I

They liquid from the centrifuge retur-nsto thelikolder,

means 2 into a centrifuge (not shown).-

cell 3| through a duct or inlet means 3 and proceeds to an orifice 4 at the rear of the holder cell' 3| into the set of plates,L It is to be noted that thc-oriuce 4 is. scparatedfrom the. Orifice.: l by a wall 9 which prevents; the liquid fronrfiow: insdilcctly trom. one orie tu the Other- From the. oi 4., the. liquid isconduuted alonethe heatiugside uf the Set of plates il to the heating.-

section` 2| and then` through channel- 2,;5: to an Huet. connection 5. ciY the hulde" Cell. 3.1; Anci" having passed through. the Zigfzae channel 2J;

the. holder. il, the lidudflows through. au Qri.

in the. upper right-hand corner of the huldsr cento., thecoolifng side ofthesct. violates. il In this, case, theA set vis placed to the right of the holdercelland not tothe left as in Fig. 1. From the. set-f. H, the liquid flows through a Channel:Q1?1 passage. Hain the lower right-hand cornerY 0f th e h0l d,er cell to the cooling sidel of; the set of; plates.v |V and, leaves the apparatus lat outlet 318.

Itwill beapparent that theholding cellor Cell:

body.. 3|, of.i my invention hasv two passages --2K4 and, 3:-4 communicating, respectively. with the heating.. sidesof; they regenerative sub#sectionsV and H, andalsdhasathroughflow channel 'tf-f3. connecting. the. cooling sides ofthe .two regenleisaf. tive.. subfsections, and these passages, andA the. channel Lg-.8i are. separated from eachother .andi from. the main. cel-lI space 2l, which is provided.

with a separateinlet and. witha separate outlet- Bfleading tothe. cooling side of the sub-sectionA Theductsl. and 31-constitutemeans forming, respectively, anoutletf-rom-passage |2` and-v an f inlet. to passagef 3 4, .so that the 4liquid being heatedj can be Withdrawn frornthe regenerative section at the 4 desiredV temperature for centrifug-Y rig-ancl returned to this section. As shown inv Fig; 4, the inlet to the main space 2l o f the holding cell is located atthe lower portion of the cell body;a't-one side, but above the passages |2 andi-4` and the channel' '|-8.

Ij claim;

1. I na plate heat exchange apparatus *havingl a main heating section and also having-a regenerative heaterdivided-into two sub-sections, each section andsub-section having a heating side and acoolingfside,` the combination of a holding cell located between the two regenerative sub-seo tion and hayvingwalls-fforming a main cellspace communicating with the heating side ofY the main heating section for receiving heated liquid` therefrom, the cell having an outlet from said space` leading to the cooling side of one sub-section*` and? also having a channel' connecting the cooling `sides `of the two fsub-sectionsfthe cell, also having two passages separated from eachV other and from said main space ancl-VV channeland-communicating, respectively, with the heat'. ing sides ofthe two sub-sections, means forming an outlet from one of said cell passages for feeding liquid to a centrifuge, and means forming an inlet to the other passage for receiving liquid from the centrifuge.

2. In a plate heat exchange apparatus having a regenerative section divided into two sub-sections eachhavingyga heating and a cooling side, the-combination of a holdingfcell locatedbetween the sub-sections and having walls forming a .main cell space, the cell having an inlet to said space and also having an outlet from said space leading to the cooling side of one of the subssctionathe .cell also. having a channel separatedifromzsaidzinlet'and outlet and connecting the :cooling-. -sideswofrthe two sub-sections, the cell also havingtwo passages separated from each other `and"'fr`om said inlet, outlet and channel andfcommunicating, respectively, with the heating sides of the two sub-sections, means forming an, outlet; from. one of said cell. passagesfor feeding liquid froxnthe regenerative section, and meansformingan inlet to. the other cell. passage. for returning liquid to the regenerativesection.

3 .A holding cellfor plate. heat exchange apparatus, .which comprises a cell body having, walls.v forming a main holding space and having an.

inlet to1 said space. and an outlet therefrom, the cell also` having; a. throughflow. channel. fory a heating liquid and, separatedfrom saidinlet, and. outlet, the. cell/also. having two passagesfor liquid4 to, be heatedand separated from each other andv from said inlet, ,outlet and. channel,`

means forming an outlet from one of said passages; andlneans formingv an inletto the other DfdSSagQ- 4. In a, plate.v heatexchange apparatus, the.V combinationz o a,l regenerative section .dividedA into two sub.-sections` each. having a heating side anda cooling side, acoupling plate located bef, tween the,t wo reggllerativesub-sections and hay ingl walls, forming. a,A holdingcell space, said holdf., ing space having, a liquid. inlet and .also. a` liquid outlet, leading toonef. side of one of the sub.- sections, thezcoupling plate; also havingl passages. separated from eachl other-and from said, h oldr. ingspaeei and communicating. with the other side.

o f. said last sub=section. and.v theA corresponding side.4 of theothersubfsection, respectively, means.

forming., .an outlet, from one, of. the passages, for, feedingliquid to acentrifuge, and means forme. ing an inlet to the other passage forreceiving liquid, from thev centrifuge.4

5.4 A, combination. according. to\ claiinV 4 in, which saidou-tlet., means are. connected through. oneofY the. couplingplate passages to the heating, sideofI one of lille regenerative sub-sections, and said'inletmeans'are connected through the other coupling plate passage to the heating side of the* other regenerative sub-section;

6j.- A' combination according to claim 4, inUv which sa-id-inletofL theA holding space is locatedl at .the` lower portionI of Y the coupling plateVV but above saidl passages-.- Y I ROBERT PONTUS LARSSONJ References Giterr inthe file of` thispatent UISIIIED4 STATES PATENTSl Number; Name Date.

1,754,857 Harrison c Apr. 15, 1930 1,92,5,i75 Album; sept. 5, 1933,- 2,392,o21 Wildermuth Jan. 1, 1946 EOREIGN` PATENTS'.

Number Country DateV 526,851 Great Britain Sept. 26; 194|)`

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