US2616270A

US2616270A - Congealing apparatus

Info

Publication number: US2616270A
Application number: US68711A
Authority: US
Inventors: Field Crosby
Original assignee: Flakice Corp
Current assignee: Flakice Corp
Priority date: 1948-12-31
Filing date: 1948-12-31
Publication date: 1952-11-04
Anticipated expiration: 1969-11-04

Description

NOV. 4, 1952 C. HELD CONGEALING APPARATUS 3 Sheets-Sheei l Filed DeC. 5l, 1948 NVENTOR M r f ATToR s Nov. 4, 1952 C, F|ELD 2,616,270

CONGEALING APPARATUS Filed Dec. 3l, 1948 3 Sheets-Sheet 2 INVENTOR Y Crosby 'Ileld NOV. 4, 1952 C, FIELD 2,616,270

I CONGEALING APPARATUS Filed Dec. 31, 1948 K 3 Sheets-Sheet 3 E l rif Q4 g g /09 1 Patented Nov. 4, 1952 CONGEALING APPARATUS Crosby Field, Brooklyn, N. Y., assignor to Flakice Corporation, Brooklyn, N. Y., a corporation of Delaware Application December 31, 1948, Serial No. 68,711

(Cl. (i2-106) 15 Claims. 1

This invention relates to congealing liquids, and more in particular to the construction of apparatus for freezing liquids in the form of solid or hollow bodies, such as ice rods or cylinders.

The present invention relates to those disclosed in my co-pending applications: Serial No. 538,768, filed June 5, 1944; Serial No. 596,738, led April 5, 1945; Serial No. 593,983, led May 16, 1945; and Serial No. 693,994, filed August 30, 1946.

An object of this invention is to provide for the efficient freezing and harvesting of ice bodies with apparatus which is inexpensive to manufacture and sturdy in construction, and which is thoroughly practical in every respect. A further object is to provide for the manufacture of ice bodies by carrying on a rapid freezing operation followed by an eflicient harvesting operation which utilizes electricity.

The above-identified applications disclose methods and apparatuses for harvesting ice by the use of electricity. Very rapid harvesting of ice is possible if there is a sufficiently high current density in the wall upon which the ice is frozen to cause a rapid heating of this wall. The heating effect is a direct function of the electrical resistance in the Wall, and the current density is a function of the voltage and also an inverse function of the resistance which depends in turn upon the cross-sectional area of the wall through which the current flows. Thus, in a thin wall there is higher resistance and at the same time less current is needed to provide a high current density, and also a thin Wall requires less heat to raise the wall temperature.

It is therefore seen that an extremely thin wall is ideal with respect to obtaining rapid heating with a minimum flow of current. However, a thin wall is not strong and will not stand the pressure of the refrigerant which produces the cooling. Thus, while a thin wall has good heating characteristics it has physical characteristics which are far from ideal when consideration is :given to the physical stresses present such as, the pressures involved in containing the refrigerant which produces the cooling effect. It is among the objects of the present invention to provide a freezing tube which has the advantages of the extremely thin sheet metal wall structure and yet which is very sturdy so that it will withstand the physical forces to which it is subjected. These and other objects will be in part obvious and in part pointed out below.

The invention accordingly consists in the fea- 2 tures of construction, combinations of elements, arrangements of parts and in the several steps and relation and order of each of the same to one or more of the others, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims:

In the drawings:

Figure 1 is a perspective view of one embodiment of the invention;

Figure 2 is an enlarged horizontal section of the freezing tube structure of Figure 1;

Figure 3 is an enlarged vertical section of the freezing tube structure of Figures 1 and 2;

Figure 4 is a perspective View of another embodiment of the invention with parts broken away; and

Figure 5 is an enlarged horizontal section of the freezing tube structure of Fig. 4.

Referring particularly to Figure 1 of the drawings, there is shown a freezing tube assembly 2 and at the right a current transformer il. The freezing tube assembly is shown in vertical section in Figure 3 and includes, a rigid metal tube 5 having a liner 8 therein with an inner cylindrical freezing surface 9 (see Figure 2). Tube 6 is surrounded by a rigid mounting structure formed by a central cylindrical evaporator section I9 which surrounds the portion of the freezing tube which includes the central freezing zone of surface 9; an upper end plate assembly I2 which encloses the upper end of the freezing tubes; and, a lower end plate assembly I4 which encloses the lower end of the freezing tube.

End plate assembly I2 is formed by a rectangular plate or block I6 of insulating material illustratively Micarta, a rectangular lower metal reinforcing plate I8 clamped to block I6 by a plurality of cap screws I'I, and a rectangular upper conductor plate 20 which is of aluminum and which is also clamped to block IS by a plurality of cap screws I9. The lower plate assembly I4 is similarly formed of a rectangular Micarta plate or block 22, an upper metal reinforcing plate 24 clamped to block 22 by cap screws 25, and an aluminum conductor plate 2E clamped to block 22 by cap screws 2l. The cylindrical evaporator assembly II) has an outer cylindrical, heat-insulating shell 28 of Micarta, and a cylindrical liner 30 of aluminum which has the evaporator formed therein by an internal helical refrigerant groove 32 therein; and, at each end of liner 30 within the ends of shell 28 there is a girdle coil 34 mounted in a collar of electrical insulation 36` As shown best in Figure 2, liner 8 is formed by: a sheet of thin metal foil 31 wound into, two concentric

cylindrical layers

38 and 40 which are connected by a web 39; an outer shell Iof metal foil 4|

land layers

42 and 43 of plastic separating the layers of foil. The foil is aluminum and is sufficiently thin to have relatively high electrical resistance, and while the plastic is an electrical insulator and has very high electrical resistance, both the foil and the plastic are relatively good heat conductors. At the top of the

freezing tube layers

38 and 40 of foil 31 are connected (see Fig-'- ure 3) -by a ring of solder 44 to conductor plate 20, thus to provide a good electric-al connection between the conductor plate and the top of these cylindrical layers of the foil.Y At the bot-tom of the tube the

layers

38 and 40 `are similarly con'-V nected to conductor plate 26 by a ring of solder s6. However, tube 6 and shell 4| have their ends covered by a thin layer of plastic 45 and 41 so that this shell and ltube are electrically insulated from the conductor plates and 26. Thus, an electrical circuit is provided by the upper conductor plate 20, the

foil layers

38 and 40 of liner 8 and the lbottom conductor plate 26.

The lower end `of the freezing tube is closed by a plate 50 and a disc-like sealing gasket 48 which is m-ounted on and held in place by the plate. Plate 50 has an integral arm 49 which extends to the left beyond the left-hand edge of the tube assembly and is hinged to the left-hand edge of plate 26 by a hinge 5|, formed by a pair of knuckles 52 welded to plate 50, a knuckle 54 clamped by screws to plate 2B and a pntle 56 extending through the three knuckles. The lefthand end of arm 49 carries a counterweight 58 which is heavy enough to urge the right-hand end of plate 50 upwardly with force suflicient to cause gasket 48 to seal the lower end of the freezing tube. Projecting downwardly through gasket 48 and plate 50 is a drain tube 60 which has .a normally closed Valve or cock 62. Thus, the bottom end of the freezing tube is normally closed, and as explained below, the cock 4is opened to withdraw liquid when such is desirable. Liquid to be frozen is delivered to the freezing tube by a sup-ply pipe or spout 64 which projects from a source not shown over the top of the freezing tube.

Referring again to Figure 1, the current transformer 4 has its secondary formed by a bus bar 66 which has its upper end clamped to conductor plate 20 by a cap screw 68 and which has its lower end clamped to conductor plate 26 (Figure 3) by a cap screw 10. The current transformer (Figure l) is of a known construction and will not be described in detail, and it is rigidly mounted on a bracket 1| as shown.

The evaporator formed helical refrigerant passageway 32 in liner 30, receives liquid refrigerant at the top and gaseous refrigerant is discharged at the bottom. The refrigerant system is represented schematically and is formed by a compresser 10, driven by a motor 12, a condenser 14 and a liquid refrigerant receiver 16. The liquid refrigerant passes from the receiver to the evaporator lthrough a pipe 18, having an expansion valve 80 therein, and the gas refrigerant is returned from the evaporator to the compressor through a conduit 82.

At the start of the freezing cycle, water or other liquid to be frozen is supplied to the freezing tube through pipe 64 to the level indicated. The refrigerati-on system is operated to reduce the temperature and freeze the liquid in a shell on the inner freezing surface `8 of liner 8. Eicient freezing is insured by the good heat transfer relationship between the evaporator and the freezing surf-ace. Illustratively, the `freezing operation is continued until the ice 'builds up as indicated in broken lines. The harvesting operation is then started by opening cock 62 and withdrawing the unfrozen liquid lto a sump (not. shown). Plate 50 is then swung clockwise so as to uncover the bottom of the freezing tube, and, 'at substantially the same time, the current transformer 4 is momentarily energized so as to cause a relatively heavy current to flow through the secondary circuit formed by bus bar 66, conductor plate 20, the

foil layers

38 and 40 of liner 8 and the 'bottom conductor plate 26. Bus -bar 66 and plates 20 Aand 26 are of such current carrying capacity that they offer no substantial resistance to 'the flow of current, but the foi-1

layers

38 and 40 are extremely thin, and therefore, constitute -a relatively high resistance path. The heavy current flowing through these foil layers produces an instantaneous heating which immediately releases lthe body of ice from the freezing surface.` The body of ice falls from the freezing tube whereupon plate 50 is swung back to the position shown, and the next freezing cycle is started. The freezing and harvesting operation may be controlled manual ly or automatically as explained in my abovementioned co-pending applicati-ons.

As explained in the cri-pending applications ref-erred to above, the girdle coils 34 prevent the ice from 'building upV along the freezing surface beyond the limits of the freezing zone. Also, while, only one freezing zone is shown in the embodiment of Figures 1 to 3, it is understood that two or more such zones may be provided in a single freezing tube, and, a plurality of freezing tubes may be mounted in abank and harvested in succession.

The freezing tube assembly comprising the freezing tube 6 and liner 8, is an integral structure. This assembly is constructed by first forming the liner on a mandrel and then inserting the liner into the freezing tube. The liner is formed by rst wrapping the foil sheet 31 onto a mandrel to form the inner layer 40; then the plastic layer 42 is put into place and the outer foil layer 38 is formed. Thereafter, plastic layer 43 is p'ut into place and shell 4| is formed. The ends of shell 4| and tube 6 are covered by insulation 45 and the liner 8, carried by the mandrel, is inserted into tubey 6 and the assembly is heated so as to set and harden the plastic layers. The mandrel is then withdrawn and the assembly is complete.

In the embodiment of Figures 4 and 5 the arrangement is somewhat similar to that of Figures 1 to 3. A current transformer 84 has a secondary bus 88 with its ends clamped, respectively, to a top conductor plate 88 by a cap screw 90, and a bottom conductor plate 92 by a cap screw (not shown). The freezing tube has a heat-insulating outer shell 96 of plastic formed in two semicylindrical sections. A liner 98 is similarin mode of construction to liner 8 and is formed by a sheet of thin metal foil 99- (see Figure 5) formedinto two spaced cylinders |00 and |02 which are held in place by plastic layers |03 and |04. Surrounding liner 98 'is an evaporator formed by a helix wound from tubing |06 (see Figure 4) of semi'- cylindrieal cross-section with the outer surface being formed by a flat surface |08 and a semicylindrical surface ||0. The helix of the tubing is wound with flat surface |08 forming a continuous inner cylindrical surface surrounding liner 98.

The upper ends of the foil layers |00 and |02 are soldered at |99 to conductor plate 88 and the other ends of these layers are soldered similarly to plate g2. Shell 9S is clamped to plates 88 and S2 by a plurality of screws l|2 so as to hold the assembly rigid. The bottom of the freezing tube in Figures 4 and 5 is closed in a manner identical with that of Figures 1 to 3, with there being a plate l Hl hinged to conductor plate 92 by a hinge i i6 and a counterweight I I8 urging a gasket (not shown) against the bottom of the freezing tube. Liquid to be frozen is supplied to the freezing tube through a pipe |20. The freezing and harvesting cycles are identical with that of the embodiment of Figures l to 3. The liner is manufactured the same as in the embodiment of Figures 1 to 3.

In each of the illustrative embodiments of the invention the heat is withdrawn from the liquid being frozen at a rapid rate by virtue of the relative high conductivity of the liner. At the same time, during the harvesting operation, the extremely thin high resistance foil layers produce a rapid rise in the temperature of the freezing surface with a current flow which is not excessive. The freezing tubes are so constructed that they have sufficient rigidity to withstand all the pressures and strains involved in the freezing and harvesting operations.

As many possible embodiments may be made of the mechanicalfeatures of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In ice making apparatus a freezing tube and evaparator assembly comprising, structure forming a substantially cylindrical evaporator section having rigid walls, and a cylindrical liner covering the inner surface of said structure and including an inner cylindrical layer of foil presenting a cylindrical inner freezing surface, said cylindrical liner also including a layer of electrical insulating material which is a good heat conductor surrounding said cylindrical layer.

2. In a freezing tube and evaporator assembly of the character described, a rigid tube, structure forming with said rigid tube a refrigerant passageway, and a layer within said tube which includes a shell of foil whichrpresents an internal freezing surface, said layer also including a heatconducting layer of electrical insulating material providing support for said shell.

3. In a freezing tube assembly of the character described, a rigid metal tube, a layer within said tube comprising a sheet of metal foil positioned in layer form concentrically with respect to the inner surface of said tube and presenting an inner freezing surface and electrical insulating means holding said sheet of metal foil in place, and means for passing cooling fluid in heat transfer relationship with the outer surface of said tube.

4. Apparatus as described in claim 3 wherein said sheet of metal foil is formed into two concentric cylindrical layers which are separated from each other by a layer of plastic having good heat transfer properties, and a layer of heat-conducting means providing electrical connections with the sheet of metal foil adjacent the ends of said tube.

5. Apparatus as described in claim 4 which includes, a pair of mounting structures positioned respectively around the two ends of said tube and each formed by a block of insulating material and a pair of metal plates clamped respectively to the opposite sides of said block.

6. Apparatus as described in claim 3 wherein the means for passing cooling fluid comprises, a cylindrical metal shell snugly fitting the outer surface of said tube and having a helical passageway around its internal surface.

7. In apparatus of the character described a shell formed of sheet metal foil and plastic having good electrical insulating characteristics With the foil presenting an internal freezing surface, a structure surrounding said shell in good heat transfer relationship therewith and presenting a cylindrical inner supporting surface to said liner, said structure having an internal passageway for refrigerant.

8. Apparatus as described in claim '7 wherein said structure comprises a rigid metal tube and a surrounding cylindrical member having an internal helical passageway.

9. Apparatus as described in claim '7 wherein said structure comprises a half-round tube which has a nat surface and a substantially semi-cylindrical surface and which is Wound in a helix with its iiat surface on the inside of the helix and forming said cylindrical supporting surface for the shell.

10. A freezing tube assembly comprising a layer formed by a plurality of concentrically positioned cylindrical layers of metal foil and alternately positioned concentric layers of plastic having good electrical insulating properties, and an evaporator and supporting structure surrounding said shell and comprising a helix formed by a tube having a cross-sectional periphery formed by a straight line and a substantially semi-circular line.

11. In apparatus of the character described, the combination of, a freezing tube assembly formed by an evaporator and supporting structure having` a cylindrical space therein and a liner within said space which includes an internal shell of metal foil and electrical insulating means surrounding said shell, a refrigeration system to produce evaporation of refrigerant thereby to cool said shell, means to supply a liquid to be congealed to the inner surface of said shell, and means to cause a relatively heavy electric current to pass through said shell.

12. Apparatus as described in claim 11 where said cylindrical space has a vertical axis, and removeable means forming a closure at the bottom of said cylindrical space.

13. Apparatus as described in claim 12 which includes a pair of sheet metal conducting plates positioned respectively at the opposite ends of said liner and connected respectively to the opposite ends of said shell thereby to provide the electrical connections therewith.

14. In ice making apparatus of the character described, the combination of, a rigid structure forming a passageway for a refrigerating fluid and presenting an extended heat exchange surface, and a liner covering said heat exchange surface and comprising a layer of foil and a layer of electrical insulating material with the layer of electrical insulating material covering said heat exchange surface and contacting and supporting the foil throughout one entire surface and with the foil having its other surface ex- 7 posed Aalr'id forming a. ffeez'ig suffe ufi which ice is formed.

15. Apparatus as described in claim 14 wherein said rigid structure is a. rigid layer of metal and a rigid member fixed thereto and having a continuous channel exposed to said layerV of metal and forming said passageway.

CROSBY FIELD.

REFERENCES CITEDA STATES PATENTS Number Name Date Windhausen Jan. 11, 1881 Williams Mar. 17, 1908 Guillemin Aug. 17, 1926 Leslie Mar. `20, 1928 Cooke Nov. 8, 1938 Gavin Nov. 29, 1938 Ross Dec. 6, 1938 Muiliy Jan. 31, 1939 Gaston Oct. 14, 1941 Short Feb. 9, 1943 Field Nov. 22, 1949