US1951657A - Refrigerant vaporizer - Google Patents

Description

March 20, 1934. E. HEHMAN REFRIGEANT VAPORIZER VFiled Feb. 17, 1931 INVENTOR. DWH/ao Ha/TMHN Patented Mar. 20, 1934 REFRIGERANT vAPoRIzEB Edward Henman, Detroit, Mich., assignor to Kelvinator Corporation, Detroit, Mich., a oorporation of Michigan Application AFebruary 17, 1931, Serial No. 516,329

v 3 Claims. .This invention relates to refrigerating apparatus and more particularly to improvements in the refrigerant fluid owing through the refrig- I erant coils to have a scrubbing or scouring effect .on the interior walls thereof. The novel combination of elements comprises a plurality of U- shaped refrigerant pipes provided with sheet metal fins, means for connecting the refrigerant pipes inA series to form a continuous coil, and means, responsive both tothe variation of pressure within the co'il and the' temperature of the outlet end thereof, for admitting refrigerant to the coil'.

Afurther object ofthe invention is the provision of `a refrigerant vaporizer consisting of a plurality of refrigerant coils projecting through a plurality of sheet metal fins, which may be built in unitary sections and assembled to form a vaporizer of any desired size.

In the drawing:

Figure 1 is a side elevational view of a refrigerant vaporizer embodying the invention, shown' in position in a refrigerator case.

Figure 2 is anend view in elevationof the structure shown in Figure 1;

Figure 3 is a cross sectional view of the thermostatically controlled expansion valve shown in Figures 1 and 2;

Figure 4 is a diagrammatic sketch of a` refrigerant condensing unit; and

Figure 5 is. a topplan View of the refrigerant vaporizer shown in Figs. land 2.

The refrigerant vaporizer loembodying this invention is `shown positioned in a refrigerated case 11. ,The case 11 has the usual outer wall 12 and inner Wall 13 with insulation material 7 disposed between the walls. The vaporizer as illustrated in Figures 1 nd 2 consists of a double row of sheet metal 1in embers 14. 'I'he fins are all substantially the same size and are spaced from each other at regular intervals. Each of the fins is provided with three pairs of vertically spaced openings 18. lIt should be understood, however, that the size of the fins and the numberand position of the openings therein may be' varied as desired.. The ins in each row are aligned so that the openings in each fin will register with the openings in the adjoining fins. At intervals "throughout the. length `of the double rows of fins 14, similar fins 15. of substantially twice the vaporizer.

length of .the ns 14, are interposed between the fins 14. These larger fins are also provided with openings 18 to correspond with the openings in the fins 14. All of the openings 18 on one side of each of the fins 14 and`15 are surrounded with flanges 17 of somewhat smaller diameter than 60 the openings 18. The two legs of a U-shaped refrigerant pipe 16 project through each pair of vertically spaced openings 18 in the fins 14 and 15 in 'each row. The pipes 16 are somewhat larger in ldiameter than the flanges 17 with the result 65 that`the anges snugly engage the pipes. The nnges 1v may be somered to the pipes 16 if desired. A good thermal contact is made however without soldering.

The U-snaped pipes 16 are positioned with 70 their open extremities all at the same Iend of the A11 of these open ends with th'e exception of the extremity of an upper leg at one side of the vaporizer and a lower leg at the op-,

posite side, are connected in series by; couplings.

19. The couplings 19 join together the alternate legs of adjacent pipes.` -In this manner the several refrigerant pipes 16 are made to form a continuous coil having open ends at its opposite extremities. The open end at the extremity 'of the upper leg is provided with a coupling member`22 adapted to receive one extremity of a suction line 23. The other extremity of the suction line is connected to the low side of a refrigerant compressor 24. As illustrated inFigure 2, a por- Ation of the outer fin 14 adjacent the pipe extremity which is joined to the suction line may be cut away to provide a protected space for the coupling 22 and the thermostat bulb 52, if desired. The open end at the extremity of the lowerleg of the pipe -'16 at the opposite side of the vaporizer is connected to the' discharge port of a thermostatically controlled expansion valve 20. The thermostatic bulb 52 of the valve 20 is preferably held in thermal contact with .the suction line 23 by means of a clamp 8. i

The condensing unit 25, in addition to the cornpressor 24, consists of a motor 26, a condenser 28, and a liquid receiver 29.v ,The motor 26 isk adapted to deliver power to the compressor 24- by means of a belt connecting a rotating Apulley on the motor 26 to the flywheel 27 of thev compressor. The compressor, condenser andV77 liquid receiver are operatively connected together in the usual manner. The liquid receiver 29,communi. cates with the expansion valve 20 by means of"a refrigerant conduit 30. The expansion valve 20 consists of a main body portion 31 and-a housing 32. The body portion 31 is provided with a centrally disposed chamber 33 and an inlet port 34 with which the liquid line 30 communicates through means of a pair of couplings 35 and 36. The port 34 communicates with the chamber 33 by means of a channel 36' and a valve opening 37. 'I'he valve opening 37 is closed by a needle valve 38 which is provided with an annular shoulder 40 and a guide rod 39. The valve is held in position to close the opening 37 by means of a spring 41 interposed between the collar 40 and an adjustable nut 42 threaded into the wall of the body' portion 31. The body portion 31 is also provided with a discharge port 43 'which communicates with the chamber 33 and is adapted to receive a coupling 44. The coupling 44 is adapted to engage a coupling 45 which is carried by the open extremity of the lower leg of the refrigerant pipe 16.

The housing 32 is securely connected to the body portion 31 and is divided into two compartments 46 and 47. An annular opening 48 provides communication between the two compartments. Communication is established between the chamber 33 and the compartment 46 by means of a channel opening 49. An expansible bellows 50 disposed in the compartment 46 surrounds the channel opening 49 and has its extremities secured in fluid tight contact with the outer wall of the body portion 31. A pair of push rods 57 projecting through openings in the wall of the body portion 31 provided for that pur.- pose on opposite sides l'of the valve opening 37 are positioned between the end wall of the bellows 50 and the collar 40 carried by the needle valve 38. An expansible bellows 5,1 disposed in the chamber 47 has its interior in open communi- -cation with the thermostat bulb 52 through means of a flexible conduit 53. The pressure of the atmosphere surrounds both of the bellows.

A pin 54 disposed in the annular passageway 48 has its opposite extremities abutting the exterior walls of the bellows 56 and 51. A spring 55 encircling the pin 54 is compressed between the outer wall of the bellows 5-1 and an annular shoulder formed in the wall of the housing 32 around the annularpassageway 48. The spring 55 exerts a pressure against the bellows 51 tending to resist the expansion thereof. A spring- 56 disposed within the bellows is positioned between its opposite walls and is adapted to assist the internal expansion thereof. The compression of the spring 56 may be varied by the adjustment of a tubular adjusting member 9.

The expansion valve 20 controls the admission of refrigerant to the vaporizer 10 in the following manner. When the pressure within the vaporizer is lessthan the atmosphere the bellows 50 is partially collapsed by the atmosphere. This partial collapse of the bellows causes the pins 57 to push against the collar 40 and force the needle Valve 38 away from the valve opening 37 which permits refrigerant to flow through the expansion valve into the vaporizer. If the temperature of the medium surrounding the thermostat bulb 52 is relatively high, the bellows 51 will be in an ex-4 panded position and accordingly assists the atmosphere in opening the valve 37. Under such a condition the valve 37 is opened when there is only a very slight difference between the atmospheric pressure and the pressure within the vaporizer. However, when the temperature of the medium adjacent the thermostat bulb is low, the bellows 50 is deprived of the assistance of the bellows 51 and a relatively great pressure difference between the atmosphere and the pressure within the vaporizer 10 is necessary to open thev valve. The .refrigerating process is accordingly carried on ata higher suction pressure than would be possible if the conventional expansion valve were used. Substantial operating economies are effected by reason of this fact.

The thermostatically controlled expansion Valve 20 admits liquid refrigerant into the lower leg of one of the outer pipes 16 of the vaporizer 10. The pathway which the liquid refrigerant must follow to reach the suction line 23 requires it to pass continually from the lower leg of a pipe to the higher leg and thence back to the lower leg of an adjacent pipe, until finally discharged from the higher leg of the last pipe into the suction line 23. This continuous circular movement of the refrigerant uid from a lower to a higher level and back again prevents the fluid from flowing freely from the inlet to the outlet. 'I'he turbulence thus produced in the refrigerant uid causes it to bombard the interior Walls of the vaporizer coil continuously. As a result of this continuous bombardment the inner Walls of the pipe 16 are kept relatively free from the film of oil and vrefrigerant', which customarily collects thereon.

The substantial removal of this film greatly increases the efficiency of the vaporizer.

The expanded refrigerant fluid is withdrawn from the vaporizer l0 through the suction line 23 by means of the action of the compressor 24 which compresses the expanded refrigerant and delivers it to the condenser 28. After being condensed the refrigerant iiuid passes into the liquid receiver 29 where it again becomes available for use in thc vaporizer l0. The refrigeration cycle is controlled by a conventional thermostat, not shown, which may be located in any desired position in the case ll.

Although the vaporizer 10 illustrated in Figures l and 2 consists of but two rows of sheet metal ns 14, joined together by means of the fins 15, it should be understood thatany number of rows of ns 14 may be used together with fins 15 of appropriate size. The rows of flns are assembled as hereinafter described in sections and joined together to form a complete unit. This method of building refrigerant vaporizers in sections materially lessens the cost of building a complete line of vaporizers as well as greatly facilitates the manufacturing and handling thereof.

v.The preferred method of assembling the vaporizer illustrated in Figures 1 and 2, comprises placing a desired number of fins 14, which have previously been provided with openings 18, in a rack adapted to retain them in spaced relation to each other. A suitable number of the larger ns 15 are placed in the rack between the ns 14 and one edge of the fins 15 is aligned with the corresponding edge of the fins 14. The two vlegs of the necessary number of U-shaped reafter the pipes have been inserted andthe rackA is refilled with the same number of fins 14 as originally used. Space is left'in the rack for the 145 interposition between the ns 14 of the projecting edges of the ns 15 already assembled. The assembled section is then placed alongside the rack with the projecting edges of the ns 15 in- Serte'd into the rack between the ns 14. 'I'he 150 openings 18in all of the fins 14 and 15 in the t rack are properly aligned with each other.

' rack. Any desired number of sections may be built into the vaporizer unitby repeating the foregoing operation a suitable number of times, and

,by using proper length ilns for joining the sections together.

After the desired number of sections have been assembled as above described, the open yends of each of the refrigerant pipes are joined to the diagonally opposite ends of the adjacent pipes by the couplings 19. The margin between the outerL pair of holes cn each of the iins 14 is of sufficiently limited extent to permit the use of the same standard coupling for joining the extremities of pipesin adjacent fins as is used injoining the extremities of the pipes both of same fin.

This method of assembling a refrigerant vaporizer makes possible the construction of a vaporizer of -any desired si from standard parts,

"' the only additional material needed being various sized fins '15 tocorrespond to the desired number of sectional units.to be employed. The same rack and the same means .for projecting the refrigerant pipes through the fins are used on all sizes of vaporizers.

It will be apparent to those skilled in the art that the structure disclosed herein is merely illustrative of the invention and that many modiiications and changes may be made in such structure without departing from thegspirit of the invention or from the scope of theV appended claims.l

which are in the' I claim: v

1. A refrigerant evaporator comprising a plurality of sectional units, each unit comprising a plurality of heat transfer fins. a plurality of U- shaped refrigerant pipes projecting therethrough, and means for connecting the ends of adjacent pipes to form a continuous coil, means for `rigidly and operatively connecting the sectional units together on the same horizontal plane comprising a plurality oflarger heat transfer fins interposed at intervals between the sec, tional fins, all of the refrigerant pipes in each of the sectional units projecting through each of the said larger ns, and couplings for joining *K the open ends of the refrigerant pipes' in each unit to the open ends of the pipes in the adjoining' unit, and means for admitting refrigerant to an open extremity of one of the units.

2. A refrigerator evaporator comprising a plurality of sectional units, each unit comprising a plurality of heat transfer fins having refrigerant pipes projecting therethrough, and means for rigidly securingthe units together comprising a plurality of larger heat transfer fins interposed at intervals between the sectional iins, a refrigerant pipe in each sectional unit projecting through the larger uns. p\

.3. A refrigerant evaporator. comprising a plu- A rality of sectional units, each unit comprising a plurality of heat transfer fins having refrigerant pipes projecting therethrough. a plurality of larger heat transfer ns interposed at intervals between the first-mentioned fins for rigidly lock- A ing the sectional units together, a plurality of refrigerant pipes in each sectional unit projecting through the larger fins, and means for operatively connecting the pipes in each pipes in the adjoining unit. r Y

EDWARD HEITMAN.

unittotliev

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