US2149737A - Heat exchanger - Google Patents

Description

March 7, 1939. l B, W JL-:WELL 2,149,737

HEAT EXC HANGER Filed May 14, 1938 4 sheets-sheet 2 INVENTOR. BER/VA RD nl Jfwfu.

ATTORNEY.

March 7, 1939. B. w. .JEWELL 2,149,737

HEAT EXCHANGER Filed May-14, 1938 4 Sheets-Sheet 3 INVENTOR.

ATTORNEY.

' at a high or a low temperature.

Patented Mar. 7, 11.9349

PATENT OFFICE HEAT EXCHANGER Bernard,l W. Jewell, Dayton, Ohio, assigner, by mesne assignments, to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware ' Application May 14, 193s, serial No. 207,955

c'olaims. This invention relates to an improvement in heat exchangers, with particular reference to condensers for mechanical refrigerating systems.

The particular application shown on the accompanying drawings is in connection with a refrigerant compressor for use in air conditioning, the heat exchanger being usedl as the condenser housed in a condensing unit, the same comprising the combination of a compressor, condenser and control means in a cabinet such as more fully set forth in the co-pending application of Burdell S. Williams, Serial No. 191,304, filed February 18, 1938 which became Pat. No. 2,116,873, May 1 0, 1938. The compressor, control means and other features which may be disclosed herein are more fully described and claimed in the aforesaid application of Burdell S. Williams, and in various other applications therein listed, all of which are assigned to a common assignee. It is obvious, however, that the present invention may be combined with other compressors in other manners, or may be used as a heat exchanger in other mechanisms.

The principal object of the present invention isto simplify factory production of condensingunits for use in widespread localities. The condenser comprises means for condensing a compressed refrigerant Vapor at a high temperature into a liquid refrigerant ,at a lower temperature, by the use of water in a water tube heat exchanger, the water tubes being coiled'within an outer shell. Factory produced condensing units of this type may be used in localities where the water is supplied at a high or a low pressure, or Accordingly, attempts at producing a single type of condenser have met with considerable diiiculty due to the fact that four conditions must be met, which conditions are the following: water at high tempera- 'ture and pressure, or high temperature and low pressure, or low temperature and pressure, or low temperature and high pressure. Likewise,.water may be scarce or expensive in certain localities so Other and further objects and advantages of my invention will be apparent from a study of the following description taken in connection with the accompanying claims wherein like numerals are applied to like parts throughout the various views.

Referring to the drawings, Fig. 1 is a front elevation of a condensing unit having the present invention incorporated therein; Fig. 2 is an end elevation of the condensing unit, having most of the end wall of the housing thereof removed; Fig. 3 is a front elevation of the heat exchanger of the present invention with a portion of the shell thereof broken away and with a portion of the Water tubes therein shown in section in order that a clearer understanding of the invention may be had; Fig. 4 is a view similar to Fig. 3

showing a heat exchanger embodying the same` principles and construction as that shown in Fig. 3, but of lesser capacity due to a. reduction in water-tube surface; Figs. 5 and 6 are bottom views of Figs. 3 and 4, respectively; Figs. 7 and 8 are side views of the heat exchangers of Figs. 3 and 4, respectively, the same having an intermediate section removed therefrom in order to reduce the spaceoccupied by the. views and having adapter heads and other apparatus attached thereto in order to illustrate the complete device; Figs. 9 and 10 are top and bottom views, respectively, of the arrangement Shown in Fig. 7; Figs. 11 and 12 are top and bottom views, respectively,

of the arrangement shown in Fig. 8; Fig. 13 isa view, similar to Fig. '7, showing the complete arrangement of a heat exchanger having the internal structure shown in Fig. 3 with a different type of header attached thereto; Figs. 14 and 15, respectively, are top and bottom views of thearrangement shown in Fig. 13; Fig. 16 is a view, similar to Fig.' 13, showing substantially the same type of header attached to a heat exchanger having the internal structure set forth in Fig. 4; and Figs. 17 and 18 respectively are top and bottom views of the heat exchanger shown in Fig. 16.

Figs. 1 and 2 show a condensing unit comprising a housing 20 having a compressor 2l supported therein in accordance with the above mentioned applications and a heat exchanger (condenser) 2 2 alongside the' compressor. Suitable controls are mounted upon a panel 23- and control the operation of the compressor in order to achieve properrefrigeration. The compressor discharges hot compressed refrigerant vapor into a discharge pipe 24 which leads to a shut-oil' valve 25, which is normally open but which may be used to isolate the compressor or condenser for inspection thereof. The refrigerant is discharged into the upper portion of the condenser 22 and is then cooled by water flowing through internally located tubes to forti a liquid which collects m the bottom of the'condenser shell. The pressure created by the compressor forces the liquid into a liquid pipe 26 which, inythis application, leads to a horizontally disposed tube 21 provided with caps 28 and 29. Either cap may be removed so as to attach tube 21 to a suitable evaporator in the locality to be cooled or refrigerated. A second horizontal tube 30 is provided with caps 3| and 32, either of which may be removed in order to attach tube 3U to the suction side of the evaporator, tube 3D being attached to a suction pipe 33 leading to the inlet of the compressor.

Water for condensing and compressor cooling purposes is admitted to the condensing unit through a water inlet pipe 40 having caps 4| and 42, either of which may be removed for attachment of pipe 40 to the source of water supply. A branch pipe 43 extends horizontally forward from pipe 40 to an elbow 44 turned upward and connected to a pipe 45 which is in turn connected to a water valve 46, the outlet of the water valve connected to a downwardly, extending, exible hose 41 which leads to a rearwardly turned elbow 48 from which a short piece of pipe leads to the header for the condenser 22. rlhe valve 46 is automatically operated by a valve motor 50 connected by tube 5| to the interior of discharge pipe 24, whereby the water may be turned on or ofi, and the amount of water flowing through the condenser controlledfin response to the discharge pressure in order to economize on the water consumption. The exible hose 41 prevents the transmission of noises and vibration from the compressor and condenser to the frame of the condensing unit and, hence, to the support and surrounding objects. The flexible hose 41 is preferably interposed between the condenser` 22 and the valve 46 in order to have a complete metallic conduit leading to the shut-off valve 46 so that the likelihood of wastage due to burst piping or tubing, may be minimized. Likewise, if the water tubes in the condenser should burst, thereby admitting refrigerant to the water system, the shutoff valve 46 will prevent the possibility of refrigerant being admitted to the water supply system.

The condenser is preferably lsupported by brackets 52, 53 and 54.welded to the shell of the condenser, and brackets 55, 56 and 51 supported by the framework of the condensing unit 20. Between each bracket welded to the condenser shell and bracket supported by the framework there are preferably interposed several, or at least one, rubber washer 58 in order to minimize the transmission of noises and vibration from the compressor and condenser to the framework of the condensing` unit.

After the water has accomplished its work within the condenser, it is admitted to an outlet pipe 60 at the top of the condenser shell, through various paths as will be presently explained. The pipe 60 is connected to a flexible hose 6| which leads to a connection 62 and into a cooling coil (not shown) within the compressor 2|. The water is ejected from the compressor through a connection 63, hose 64, elbow 65 and pipe 61 leading to the water outlet pipe 68. The flexible hoses 64 and 6|. minimize the transmission of noises and vibration from the compressor, and permit greater flexibility in manufacturing since close limits need not be held. The pipe 68 extends horizontally across the backV of the condensing unit parallel to inlet pipe 48 and is provided with caps 69 and 18, either of which may be removed to permit the connection of the condensing unit to a water removal system at either side.

The condensing unit is preferably provided 5 with a drain pan 1| having a drain outlet 12 which may be turned in any direction, as described in the aforementioned application of Burdell S. Williams.

The condenser 22, as shown in Figs. 3 and 4, preferably comprises two pressed-steel sections 15 and 16, each forming substantially half of the condenser shell, the two sections being welded together adjacent an inner band 11 to form a gas-tight enclosure. lThe lower section 16 has a tube, sheet 18 aiilxed thereto by means of legs 80 welded to the bottom of the shell. The tube sheet 18 forms a support for the ends of thewater tubes which pass through the condenser. The end of the upper half 15 is provided with an outlet header 8| aihxed to the surface of the shell by legs 82 which are welded to the shell.

In Fig. 4 a water-tube arrangement of one capacity is shown while a water-tube arrangement of greater capacity is shown in Fig. 3. For simplicity, Figure 4 will be described rst, the same comprising an arrangement consisting of two sections of coiled tubing, the .lower section 83 being `iitted within the lower half-shell and the upper section 84 being fitted within the upper half-shell. One end of the section 83 comprises a straight shank 85 which passes through the bottom of the shell 16 into the tube sheet 18, the shank being made integral with both the condenser shell and the tube sheet. As soon as the tube of the lower section has passed within the condenser shell it is provided with fins or other means whereby the heat transferring coeicient of the tube is increased, and is formed into a coil which extends upward to the middle of the condenser. At 86 the tube is bent downward to form a long central shank 81 extending through the bottom of the shell and into the tube sheet, being made integral at both points. The upper section 84 comprises a long straight shank 88 which extends beyond the middle portion of the condenser and joins a coiled finned section which rises to the top of the condenser shell. At 89 the tube is bent upward to form a shank 90 (Fig. 8) which extends through the top of the condenser shell into the outlet header 8|, the tube being made integral with the shell and header.

The arrangement shown in Fig. '3. permits of greater capacity due to the inclusion of a double set of coils achieved by arranging smaller coils within the outer coils. The lower\half of the condenser contains not only the coil 83, previously described. but a second smaller coil |90 having a straight shank 9| fastened to the shell and to the tube sheet and a return shank 92 fastened to the shell and the tube sheet. The upper half of the condenser shell contains the large coil 84 and a smaller coil 94 nested within the other coil, the smaller coil having a straight shank 95 fastened to the lower end of the condenser shell and the tube sheet, and an upwardly extending straight shank 96 fastened to the upper half of the condenser shell and the outlet header, the outlet header being provided with a boss for each of the tubes 90 and 96, either or both of which may be drilled depending upon the number of coils within the condenser.

Figs. 5 and 6 show the ends of the tubes ar- 75 vcompleted' condenser of which the details are magnum the :une sheet 1s for rames sans 4, respectively. Figs. 7, 9 and 10 are views of the given in Fig. 3, when the condenser is arranged .for low pressure or high temperature water; and

)du is 'connectedto the inlet space lill.l through the water valve ES, hose 0l, elbow 48 and short section of pipe- HM joining the elbowand inlet header we. Water entering the/space |02 flows upward through tubes 05, 88, 9| and 95, so that there is water A:dowing through Vthe coils 83, 86, llull and 93 in an upward direction, the temperature of the water being substantially equal at the bottom and at the middle of the condenser. Since the hottest refrigerant enters the condenser shell adjacent the top thereof, coils Bl and 9d are preferably shorter than coils 83 and |90, in order that the same amount of Work may ibe done by the water flowing through 'the two halves of the condenser. The water which ilows through the upper half of the'condenser passes upward into the outlet header 8| through tubes 90 and 9S, while the water which flows through the lower half of the condenser returns to the return space |03 through tubes 87 and 92.. 'I'he inlet header |00 is provided with a boss |05 which is drilled and connected to a by-pass |06, which is connected at its upper end to a boss |01 in the outlet header 8|, the by-pass |06 delivering the heated water from the lower half of the condenser to the outlet header. The outlet header is connected to the hose 6| Which delivers all of the Water tothe cooler (not shown) in the A compressor and thence to the waste pipe 68. The

cooled liquid refrigerant is ejected through an elbow ||0 vwhich is connected to the liquid line 26. The arrangement shown in Figs. 8, ll and 12 illustrates the same type of parallel ow for a condenser having only-a -single pass of water tube. In this case the water leaves the inlet space |02 through tubes 85 and 88, the water passing through tube 05 returning to the re turn space |03 by way of tube 81, thence to the outlet header 0| through by-pass |06 where it joins the water iiowing through the upper coil 84 which reaches theoutlet header by way of tube 90. A

Figs. 13, 14 and 15 illustrate a condenser arranged for series-how, double-pass and Figs. 16, 17 and 18 illustrate a condenser arranged for series-flow, single-pass, thereby achieving the greatest economy in water consumption where high pressure or low temperature water is available.

' an inlet space |32 and a return space |33. Water into the .outlet header 0| by way of tube 90.

-order to provide for the internal iianges lul', or

specuvay, lnto the upper coils sa anaal; there: by re-using the previously heated water in contact with the hottest gas. All of the water then enters the outlet header 8| through tubes 90 and 96. In this case no by-pass is necessary so that 5' the bosses |05 and |01 are plugged.

Fig. 18 shows thel header |30 for adaptation of the condenser of Fig. 4 to series-now, the l header being provided with a ange |3| forming which enters the inlet space |32 flows upward through tube 85 and coil 83, then back into the return space v|33 by way of tube 8l. The'same water then flows out of return space |33 by way of tube 88 into coil 00 and dut of the condenser It is to be noted that, the same type of inlet header is used in all cases, it being very simple to change the mold in which the headers are cast in l2! and |22, or |3l, as desired. Also, the' same outlet header 8| is used, the same being/drilled to accommodate tube 90 alone, or'tubes 00 and 96. It is also to be noted that the same tube sheet 78 is used in all cases, the same being drilled 25 to accommodate the tubes 85, 0l and 88 alone, or the tubes B5, 8l, 88, 9|, 92 and Q5. I have thereby materially reduced the number of parts necessary to' purchase for inventory, and have made it possible to be prepared to ll orders from all sections of the country by using identical pieces of material. In this manner it is no longer necessary to keep a supplyl of a large number of different' sizes and capacities of condensers, it being evident that the various parts are standardized and may be modiedand assembled to fulfil orders as received at the Shop. Figs. 3 and 4 show a detail whereby the assembly of the unit is made' practical. A plurality of blocks U10, preferably made of a material immune to the attacks of yrefrigerante and oil, are positioned at spaced vpoints around the outside of the larger coils, the blocks being formed partially to brace the iinnedy tubes and having a rounded outer surface. The material is preferably resilient so as to conform to unevenness in the shell and coil diameters, but of suicient elastic rigidity to be tightly compressed when the coil assembly is slid in the shell in order to hold the coils from vibrating against the inner'surface of the shell. The inner, smaller coils are held in position preferably by Wiring the same to the outer coil bymeans of wires Ml. l

It is to be noted that all of the inlet headers |00, |20 and |30 are provided with plugs |05r which may be removed in order to drain the water A from all of the coil sections when the condenser is being stored, shipped, or prepared for the winter months, in order that no water can remain within the coils to corrode the inner surfaces or to freeze and burst the coils.

Having now described the preferred embodiments of my invention, it should be apparent to those skilled in the art that modications in arrangement and details there'of may be achieved, and all such modications as come Within the scope of the following claims are considered a part o f my invention.

I claim:

1.' A heat exchanger of the shell and tube type comprising a shell having a plurality of tube coils arranged therein, a tube sheet alxed to one end of said shell and having the inlets to each of said coilsk aidxed thereto, an outlet header aiiixed to the other end of said shell and having the outlet of at least one of said coils affixed thereto and communicating therewith, and an inlet header removably attached to said tube sheet, said inlet header being divided into at least two spaces, one of said spaces comprising an inlet space communicating with the inlets to each .of said coils, and at least one other of said spaces comprising a return space communicating lwith the outlet of at least one coil other than the said coil having its outlet a'ixed to said outlet header.

2. A heat exchanger of the shell and tube type comprising a shell having two sections of tube coils arranged therein, one' section occupying substantially one-half of the shell and the other section occupying substantially the other half of the shel1,'a tube sheet aiilxed to one end of said l shell adjacent the first-mentioned section. of coils and having` the inlets to each coil .affixed thereto, an outlet header afxed to the other end of said shell adjacent the second-mentioned sectionof coils and having the outlet of at least one of the coils of the second-mentioned section aixed thereto and communicating therewith, anld an inlet header removably attached to said tube sheet, said inlet header being divided into at least two spaces, one oi' said spaces comprising an inlet space communicating with the inlets to each of said coils, and at least one other of said spaces comprising a return space communicating with the outlet of at least one coil of the firstmentioned section of coils.

3. A heat exchanger of the shell and tube type comprising a, shell having two sections of tube coils arranged therein, one of said -sections occupyingA substantially half of said shell at one end thereof and comprising a first coil of large size adjacent the inner surface of the shell and a second coil of smaller size nested in said rst coil, and the other of said sections being located in the other half of the shell and comprising a third coil of large size adjacent the inner surface of the shell and a fourth coil of smaller size nested in said third coil, a tube sheet afllxed toone end of said shell adjacent the first-mentioned section of coils and having the inlets to each of said coils affixed thereto, an outlet header affixed to the other end of said shell adjacent the secondmentioned section of coils and having the outlet of at least one of the coils of the second section aflixed thereto and communicating therewith, and an inlet header removably attached to said tube sheet, said inlet header being divided into a plurality of spaces, one of said spaces comprising an inlet space communicating with the inlets to each of said coils, and at least one other space com- `municating with the outlets of said first and second coils.

4. A heatexchanger of the shell and tube type comprising a shell having two sections of tube coils arranged therein, one section occupying substantially one-half of the shell and the other section occupying substantially the other half of the shell, a tube sheet aiiixed to one end of said shell adjacent the first-mentioned section of coils and having vthe inlets to each coil afiixed thereto, an outlet headeramxed to the other end of said shell adjacent the second-mentioned section of coils and having the outlet of at least one of the coils of the second-mentioned section affixed thereto and communicating therewith, an inlet header removably attached to said tube sheet,

said inlet header being divided into at least two spaces, one of said spaces comprisingan inlet space communicating with the inlets to each of said coils, and at least one other of said spaces comprising a, return space communicating with the outlet of at least one` coil of the rst mentioned section of coils, and a by-pass leading around the outside of said shell from said return space into said outlet header.

5. Av heat exchanger of the shell and tube'type comprising a shell havingltwo sections of tube coils arranged therein, one of said sections occupying substantially half of said shell at one end thereof and comprising a first coil of large size adjacent the inner surface of the shell and a second coil of smaller size nested in said first coil, arid the other ofsaid sections being located in the other half of the shell and comprising a third coil of large size adjacent the inner surface of the shell and a fourth coil of smaller size nested in said third coil, a tube sheet aixed to one end of said shell adjacent the first-mentioned section of coils and having the inlets to each of said coils afiixed thereto, an outlet header aillxed to the other end of said shell adjacent the second-mem' communicating therewith, and an inlet headerl removably attached to said tube sheet, said inlet header being divided into two spaces, one of said Spaces comprising an inlet space communicating with the inlets to each of said-coils, and the other of said spaces comprising a return space communicating with the outlets of said first and second coils, and a by-pass leading around the shell from said return space into said outlet header.

6. A heat exchanger of the shell and tube type comprising a shell having two sections of tube coils arranged therein, one of said sections occupying substantially half of said shell at one end thereof and comprising a first coll of large size adjacent the inner surface of the shell and 'a second coil of smaller size nested in said first second-mentioned section of coils and having the outlets of said third and fourth coils amxed thereto and communicating therewith, and an inlet header removably attached to said tube sheet, said inlet header being divided into, three spaces,

one of said spaces comprising an inlet space come municating with the inlets to said first and second coils, the second of said spaces comprising a return space communicating with the outlet to said rst coil and the inlet to said third coil, and the third of said spaces comprising a return space communicating with the outlet of said second coil and the inlet of said fourth coil.

' B. W. JEWELL.

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