US1857892A - Heat exchanger - Google Patents

Description

May 10, 1932. J. 1.. TURNER ET AL 'HEAT EXGHANGER Filed Nov. 29, 1950 Patentea May 10, 1932 iixcHANGER e simple i oons'triic'tioii,` economicai* to menu'- facture and o'perate, and highly efficient in v]' :`e`rf`)`'rinjmio'e- Apparats' lnde in accordance'with the nvention nray be' used to trans'- fer thermal' imits from one? fluid to another and it'` is enV object to 'soar'range the 'paths of flow of thee fiuids? that the on'e being atted upon;A asitwere, is piesented tozthfe ii-'ifloeiiee of the other'- fiiiid iii thiii5 honoiv f stream with the eetiiig` floidi fiowiiig: both vl' inside and outside Of this stream i'n`` close .20 these elements changes in accordance with ,25 is' 'a feeture to provide in ohhinatih' theheat exchinger proper an cilatlon Chamber' into whioh the ,ossifiedi retrigeiiaiit iiiaiy d'isohai'ge o iid from which the liquid refrige'rnt Ina'y' be fe'd byl g'r'vity'to the'be .30 ofv the evaporator. It is also av feature to provide ef novel baifle' foi' eriestiii'g ;iiny `liquid particles entrziined in the gsified refrigerzi'nt entei'ingl the e'coumulotioiiv ohziinherV end pre;

venting theirf'uithei1 travel with the gas. Other objects and features of Vcol'istrdotio'n will be iioted as the vdetfiiled description develops. i i The best mode in which wehaveeoiiteiiiplated applying' the pririeiples of our iiiv-entio is'di'sclosed in the ac'companing drztvving's'in the form of a casilngw'hih o oritins the fiuid'that is to give 'p or receive heat froin another flid; Near the top of thi'sfc'sing7 is o; header which supports a' second header,-e1ose by the bottonigoi the 'cosifig, h means of a series' of peiis' ofiiested. tubes. The'outer tiibe of estch'pair' forms .a'- flow connection between' the two iheadeiistor passgfe of the' fliiid'to' he eeted dpoii while? the 50 iniier: tube. of each pair extendsheyoiidV the eiids of Vthe oiiter tuhes'tjhioghhoth'heodes and 'constitte's ;a'z psg'e for` fi'ow 'of the 'dating fliiid. Since the ihttet is also iii'ooiita'et with the itside 'of the o ii'ter tube of 'e'h paihthe exohaiigeofhet to oi' from the fiiiid os octed oponie exc'eediirgly'high iii proportion to the size 'of the heat exzhaii'gei'. f It is inteiided thjat the' piteht 'shall oovei' by 'suitibre expressionjiiithje oppeirded'oliifis `whatevervv feature of pateriittble novel'ty exists to in vthe linveritin'disolosed.

Iiithe hooompmying dralwirfgs i ;1 Figure I mi 'eievhtiong iiriiiediiv setion, (as on linee 1--1 of F ig.` 2) of a heat en*- chaii'ge'r construptedx iii aeoi'danee with the prinoiples of this iriventioii; i

vFigure* 2 is'a' pfla'ii o'fa 'section' taken as oh line` f'orfj Fignre li; f

i Eigiii'e 18 isaiiother elevation; showing the adaptati'on of` the exclinger as: an evaporatoi 7* inV combiniition with an* acouiulatlo c'hnibei' and "a,` device for 'cofn'trllingV the supply of liqndz rerigernt5v lnd i i .i i F,.Fi%uije 4-is a plan inv section o'nfline: i-*of igii 1 c Referring m're prticiilarl tothe drawings the heatexchhger coniprises a twoi part esing IO which` i's'` here shownin the form of a' cylinder havinga tightlfiy sealed bottom l'ridtopfl; At the upper edge of the lower pztt' IOafi's. attached a cfollarfli which servesin onjhnction'with' a siiilai' co1lztr 16,`attacheditothe upper prt: 101;, to clmp eheder 20 sefcnreflyl between them. This header :is annnlaiii 'Shape nd sur`- rounds opening 22 thbug'h it'atiits center. Its'outer Wall has both' anupstandingfrir Oa'ondf a depending ri1i1 20b which en age co-'o`p`erttir`1g` grooves inth'e* collrr -14f16-fso thitt upoir the? `lolt's'i 21: being:` 'tig'htened the :9`0 top'pai't'lbblietder 20 a'ndbottoin part 101'1 are Wseiireo'ffirnilyv together? there beig gaskets 28 toopifeveiitzty'leakegei A seooiidhettder'f lt'similar iii 'sha'p-to the top 'header i'sfV provided nr the bottom of the osih-,fihot is 'not directly ttiio'hed 'thereto'.. Oii'the' 'contraryfitfis ffe'a'tureto support thishe'ader' iii the ossing'hy iiiean's'of eseriezs of pipesJ 26, 28 connecting it to the tdpheidei';

With the pipes of each pair having their longitudinal axis concentric. The outer pipe 26 of each pair extends between the bottom plate 200 of the top header 20 and the top plate 24a of the bottom header 24 thus connecting the interiors of the two headers. The inner pipe 28 of each pair exends through the outer pipe and is joined to the top plate l2061 of the top header and' the bottom plate 246 of the bottom header. Accordingly, these inner pipes serve as passageway's through both thel head-` ers and the outer pipes. 'i i w As herein shown the top header is divided into two compartments by partitions` 34 which cause the fluid entering by connection 30 to pass, downwardthrough the three pipes 26 nearest thereto into 'the bottom header. From the latter the fluid passes upward through the other three pipes 26 into the other compartment of the top header. from -whence it goes on through the outlet 32. Such an arrangement aifords a rather short course of flow for the fluid to be acted upon,'but this may be greately increased by the provision of additional partitions in the upper headers and others in the lower headers, so that, if desired, thefluid may successively transverse all the outer pipes connecting the two headers.

liquid, steam or other high temperature fluid, is supplied to the casing through either the pipe 40 connected near the bottonior through Vthe pipe 42 connected to the top. This highly heated medium flows thence through the casing, part of it bathing the outside of'the headers and the connecting pipes 26 andpart of'it flowing` through the inner pipes 28. Simultaneously with this flow of theheatgivingfluid, there is fed to the upper header the fluid to be heated. This enters the header and by virtue of the partitions therein is forced to pass tothe lower header through the thin annular space formed between the pipes of each pair. After reaching the lower header this heated fluid is then forced through similar annular passages formed by other pairs of pipes back to the top header from whence it discharges. Since the fluid' to be heated is in the form of a thin annular hollow stream as it passes from one header to the other, and since'both theinside 'or hollow of this stream and theoutside are in close proximity to the heat-givingfluid, the increase intemperatureof the'fluid being heated is exceedingly rapid, ,andl since' substantially all the heatiof the' heat-ing fluid is available to the heated fluid (it being conitemplated that the outer surface Vof the exchanger will be properly insulated to guard against any appreciableheat loss) it is evident that the effectiveness of 'the apparatus is very high.

iWhile it is preferable to circulatethe acting The acti on. of the exchanger `isas -follows v When used as a heater, the acting-fiuid,vhot

42 into the accumulation 'Chamber ,sirable to form the upper part of the casing so that'it may serve as an accumulation chamber,as seen in Figure 3. The top plate 13 becomes the bottom of this Chamber 103)' and the outlet 42 extends upward therein to about the level 1-1 at which the liquid re'- frigerant is to be maintained. In proximity to the uppervend of this outlet 42 is a bafile 44 in the form of a plate extending across the chamber, slightly wider in width than the Outlet opening, with depending sides 44a converging to the outlet pipe 42. lFrom the top of the header a connection 46 leads to the usua-l compressor and another connectionV 48 leads to a float chamber 50 in which is a float 52 pivotally mounted with shaft 54.: A crank 56v on the latter is connected by a link 58 to another crank 60'which in its turning controls the Valve 62 that is in the supply line 64 connected to the accumulation chamber. From near the bottom of ,the latter is a connection 66 to the floa-t Chamber and another connection 68 leading to the bottom'ofrthe caslng. I I

Anhydrous ammonia or other suitable refrigerant'is fed to the accumulationl chamber at a rate determined by the level of liquid therein, this level of course being the ;same as that in chamber 50 affecting the float.

VAny fiash gas occasioned by this supply feed is taken care of in the accumulation chamber and' has no effect on the evaporator proper. Thel liquid refrigerant feeds by gravity through connection 68 to the bottom of casing 1`0 from whence it passes upward around the lower header 24 and through its central opening and thence through the opening 22 in the top header. Part of it of course flows through the inner pipes 28. It takes up heat from the vfluid which is siinultan'eously being fed through the headers and the thin annular'spa'cesV between pipes 26 and 28. Naturally this heated (as it were) refrigerant would rise through outlet 42 and thus effect a thermo-circulation; of the refrigerant,'but with anhydrous ainmonia, the refrigerant is also transformed to a gas in the form of bubbles which rush up Outlet particles of liquid entrained in this gas, or caused by the spattering as the bubbles reach the surface of the 'refrigerant, Vare trapped by the 'baflie 44 and prevented 'from passing on into connection 46. The transformation Any of the refrigerant into gas and its withdrawal as such by the compressor, tend to lower the liquid level in the accumulator and float chambers as the flow through connection 68 continues. This brings about an opening of the valve 62 to admit additional liquid from the supply until the desired level is restored. In practice is is found that the level is very closely maintained, the fioat and valve assuming that position where the supply substa-ntially equals the withdrawal of the refrigerant by the compressor.

The possibilities of adapting the heat exchanger to any desired duty is evident. Few or many pairs of tubes can be provided as conditions warrant, and the length or depth of the casing and tubes can be altered as Well to increase or decrease the effective transfer space provided between the inner and outer tubes. The simplicity of the elements is also easily appreciated. Standard pipes and fittings only need be used 'for the casing and general connections and the headers are easily formed by casting. The Suspension of the lower header by the connecting pipes enables this header to move without strain on the casing in the event of any elongation or contraction which may result from changing temperatures. vantageous When the same exchanger is to be used part of the year as a heater and at other periods as a coolerJ `The pronounced compactness is also a characteristic feature of the exchanger, and makes it possible to install the apparatus in places and spaces where exchangers heretoavailable have not been adaptable.

We claim:

1. A heat exchanger having a two-part casing adapted to receive and discharge a fluid; an annular header secured between lthe parts of said casing, having connections for receiving and discharging another fluid; and a second annular header supported within said casing by a. series of pairs of tubes; the tubes of each pair being arranged one inside the other, with the outer tube secured to the adjacentwalls of the headers and forming a passageway between the headers, and with the inner tube attached to the remote Walls of the headers and fo-rming a passageway for the casing fluid. w

2. A heat exchanger having a casing adapted to receive and discharge a Cooling fluid; a pair o-f headers associated therewith adapted to receive and disoharge a fluid to be cooled; a series of pairs ofitubes extending between said headers, the tubes of each pair being arranged one inside'the other witht-he outer tube forming a. passageway between the headers for the cooled fluid and with the inner tube extending through said headers and forming a passageway for the Cooling fluid; a partition across said casing above the headers to form an accumulationcham- This is particularly adi ber thereabove; a tube extending upward in said chamber from said partition; a connection between the accumulation chamber and the bottom of said casing for transfer of the cooling fluid; and means associated with the accumulation chamber for main- `of the refrigerant; a partition across said caslng provlding a space above said headersV and tubes into which the refrigerant passes from the tubes as a gas; an accumulation chamber above said partition; a tube extending from said partition into said accumulation chamber; a baffle at the outlet of the last said tube for arresting any liquid particles entrained in the gaseous refrigerant entering the accumulation chamber; means for maintaining a supply of liquid refrigerant in the accumulation chamber; and a connection betWeen said chamber and the bottom of the casing for transfer of said liquid refrigerant thereto whereby it may pass upward through said inner tubes and thereby absorb heat from the fluid to be cooled.

4. A heat exchanger comprising a casing adapted for circulation of a fluid and having o opposed parts, a header between said parts having a groove and tongue connection therewith, means for clamping said parts and headers together; a second header inside said casing, supported from thefirst mentioned header by a series of tubes arranged in pairs with one tube of each pair inside the other tube thereof; the inner tubes of said pairs extending through said headers and the outer vtubes opening into the said headers thereby,

to form a tortuous passage for flow of fluid separate from the path of flow of the casing fluid. a

Signed at Milton, Massachusetts, this 24th day of November, 1930.

J ACOB LEE TURNER. JAMES G. RUSSELL.

ioo

Images