US3070967A - Dry ice manufacture - Google Patents

Description

Jan. 1, 1963 T. L. UREN 3,070,967

DRY ICE MANUFACTURE Filed Sept. 3. 1959 5 Sheets-Sheet l INVENTOR AT TORNEVS Jan. 1, 1963 T. L. UREN 3,070,967

DRY ICE MANUFACTURE Filed Sept. 3. 1959 3 Sheets-Sheet 2 lA/VENTOR ATTORN)S.

Jan. 1, 1963 T. L. UREN 3,070,967

DRY ICE MANUFACTURE Filed Sept. 3. 1959 5 Sheets-Sheet 3 254 ENTOR: kilh w B) ATTORNEYS.

ga a ts ilnited This invention relates to Dry Ice manufacture, and more particularly to an operation in which snow is formed continuously by the expansion of liquid carbon dioxide and the snow compacted in Dry Ice blocks.

An object of the invention is to provide a machine and method for the continuous forming of CO snow and the compacting of the snow into blocks of varying sizes. A further object is to utilize in such a machine and process means for producing a sudden release of the snow to permit its being compacted by compression apparatus, while at the same time utilizing incoming, relatively warm, liquid CO and returning revert gas formed in the operation to the compressor. A further object is to provide in such a process and apparatus, effective means for controlling the formation and release of Snow, the compacting of the snow into blocks of a desired size, the ejecting of the blocks while still held under compression, the control of the return flow of revert gas, and other important steps in the manufacture of Dry Ice. A still further object is to provide a compact machine which may be employed effectively for the production of relative small quantities of Dry Ice as the same is required, the apparatus being relatively inexpensive and representing a relatively small mass of metal to be cooled in the manufacturing operation. Other specific objects and advantage; will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawings, in which FIG. 1 is a side view in elevation of apparatus embodying my invention; FIG. 2, an enlarged broken vertical sectional view of the upper portion of the snow tower or column; FIG. 3, a developed perspective view of the compressor piston and associated parts, the same being shown in spaced-apart relation; FIG. 4, an enlarged vertical sectional view of the snow tower or column and the compression cylinder communicating therewith; FIG. 5, a transverse sectional view taken atthe point of union between the two parts of the snow tower as indicated by the line 5 of FIG. 4; FIG. 5-A, an enlarged detail sectional view showing the bottom of the column and tower and the space therebetween; and FIG. 6, a perspective view of the indicating means employed with the compressor for showing the size of the block formed in the compression step.

In the illustration given, A designates a snow tower and B a compression cylinder.

The snow tower, as shown best in FIG. 4, employs a vertical column 10, which may be of relatively uniform diameter. Within the column is supported a coneshaped chamber 11. Both of the cylinders 10 and 11 are separated at an intermediate point by flanges 12 and 13 and with a closure plate 14 therebetween. The closure plate 14 has three apertures 15 therethrough, each being adjustably controlled by a threaded screw or closure 16, as shown more clearly in FIG. 5. The purpose of the structure is to control the flow of gas through the chamber space provided by the cylinders 10 and 11 below the plate 14. As will be later described, revert gas may pass upwardly through the lower space between cylinders 10 and 11 and through the apertures 15 into the larger space between the cylinders and above the plate 14, the larger space being indicated by the numeral 17.

Within the space 17, there is a reverse coil 18 for ates Patent ice carrying liquid CO (usually at a temperature of about 60 F.), the coil passing downwardly through the cylinder and then being reversed upon itself and extending out of the cylinder through line 19. The inlet to coil 18 is indicated at 18a and such inlet pipe may extend to any suitable source of liquid C0 The cooled CO in pipe 19 passes through control valve 25) on the instrument box 21. On the box 21 may be mounted suitable guages for indicating the pressure in the snow tower and other portions of the apparatus and which will aid the operator in the operation of the machine. When valve 26 is opened, the liquid CO will pass through pipe 22 to the expansion nozzle 23 at the top of the cone cylinder 11 controlled by valve 23a. The expansion nozzle or valve may be of any suitable construction, and is preferably of a type which will give a nice control of the release of the liquid within cyLnder 11 so as to form snow therein. In the illustration given, the liquid CO is released through the valve and discharged through the pipe 24 into the cone 11, which is preferably formed of stainless steel.

I prefer to equip the tower with a safety closure plate 25 which is held in place by springs 26, as shown more clearly in FIG. 2.

The compression cylinder B comprises preferably a horizontal cylinder having centrally thereof an opening 27 communicating with the bottom of cylinders 10 and 11. The cylinders 10 and 11 are slightly spaced apart at their bottom, preferably by about 5, so as to provide a small orifice through which revert gases may pass upwardly in the space 28 between members 10 and 11.

The compression cylinder 13 has a discharge end 29 closed by a movable gate 30 carried by the discharge plunger 31. The plunger 31 engages a piston (not shown) mounted within the hydraulic cylinder 32 to which pressure fluid is supplied through lines 33 and 34 from the motor-driven pump 35. Control of the pressure fluid is through a valve 36. Pipe 33 is provided with a restrictor valve 37 for the purpose of maintaining pressure upon the block of ice while it is being discharged tor a limited period of time.

Opposite the discharge end 2% of cylinder B is mounted the compressor piston 38. The compressor piston is actuated by the plunger shaft 39 which extends through the piston 33 and rearwardly therefrom through plate 40 and which is connected to a piston (not shown) in the hydraulic cylinder 41. Fluid from the pressure pump 35 is supplied to opposite ends of the cylinder 41 through the pipes 42 and 43, and the flow of the fluid is controlled by the hand valve 44, or, optionally, by the foot-operated control 45.

The compressor piston 38 may be provided with leathersealing rings 46 and at its forward end with a pad 47 formed of leather or other flexible or resilient material which will retain its resiliency under the intense cold conditions encountered within cylinder A. I have found that leather is most efiective under these conditions of intense cold, having no tendency to stick to the Dry Ice blocks and permitting a ready discharge of the blocks when formed.

When the liquid CO is expanded, there is formed both snow and revert gases, and the present invention contemplates the return of the revert gases through the chambers 17 and 28 and back to a compressor, and it is desired to utilize the revert gases in a heat exchange contact with the incoming, relatively warm, liquid CO in the coil 18, while at the same time raising the temperature of the re vert gases going back to the compressor. To this end, revert gases are allowed to flow upwardly through two separate channels. One channel is through the lower ends of the spaced cylinders 19 and 11 and into the space 28 and thence through the plate openings into the space 17.

about the cone.

Another channel is upwardly through the forward portion of the cylinder B into communicating boxes 48 and 49 and thence through pipe fit} into the chamber space 17. Box 48 is in open communication at its bottom with cylinder B and communicates with box 49 through opening 43a. The pipe 54 leads from the top of box 49 for carrying revert gases to cylinder space 17. I prefer to pass the revert gases through a check valve (not shown) within the box 49 and warm oil returning to the oil reservoir is passed through the box 49 about the check valve so as to prevent it from freezing in the operation of the apparatus, while at the same time the hydraulic oil is cooled.

Revert gas from the two channels indicated leaves the top of the chamber 17 through the valve-controlled pipe 51 and back to the compressor.

In order that the operator may know immediately the size of the cake of Dry Ice produced in the compression operation, I prefer to secure to the plate 4% mounted on the compression piston shaft 39 a rod 52. The rod 52, as shown best in FIGS. 3 and 6, is connected by bracket 53 to an indicator rod 54 slidably supported within the sleeve 55. The rod 54 extends over a scale 56 and with each reciprocation of the piston 38 the operator can determine the thickness of the Dry ice block formed within the compression cylinder.

Operation In the operation of the apparatus, liquid CO which may be relatively warm, enters the coil 18 extending about the cone 11, where it gives up heat to the surface of the cone 11 while at the same time meeting the cold revert gases passing upwardly through space 17. The chilled liquid CO is then allowed to flow, when valve 2 is open, through pipe 22 and the expansion nozzle 23 for the forming of snow Within the cone 11, where when the piston 38 is in its forward position a pressure in the neighborhood of twenty pounds per square inch is built up. The snow, as it is formed while the piston is in its retracted position, drops downwardly into the compression cylinder B and is compressed by the forward movement of the piston 33. For effective operation of the apparatus, it is important that there be a quick release of the snow, and it is found that when the piston 38 is retracted in its operation from the discharge end 29 of cylinder B, there is a sudden drop in pressure in the cylinder and the pressure that has been built up within the snow cone 11 causes a quick release of snow filling the compression chamber for the next compression operation. Such sudden release of snow is further effected by the shape of the cone chamber 11 and by the effect of the warm coil 13 Thus, in the reciprocation of the compression piston 33, it is found that there are quick or sudden releases of snow as the piston is retracted to the position shown in FIG. 4, so that almost immediately the piston may be moved forwardly to effect a further compression of the deposited snow.

The operator, by the actuation of the valve 44, may cause the piston 38 to be repeatedly withdrawn and advanced to increase the size of the Dry ice block to the desired thickness of, say, seven or eight inches. The indicator rod 54 automatically shows the thickness of the block, and when the block is to be discharged, the operator moves valve as to cause a retraction of the closure plate 30.

In order to prevent the Dry lee block from exploding or breaking up as it is suddenly released from the cylinder is, I prefer to maintain the closure plate 39 firmly against the block at one end thereof as the block is being ejected by piston 33, and, to this end, the restrictor valve 37 brings about such pressure. After the block has been released from the cylinder for a few seconds, it may be released and allowed to fall into the Dry ice receptacle indicated by the numeral 57. The receptacle may be formed of canvas or other material for receiving the Dry 6!. ice block without injury to the block. The outlet end portion of cylinder B near the gate or closure 30 is slightly flared to facilitate removal of the block.

in the foregoing operation, revert gases formed in the operation may return while the piston is in retracted position through the boxes 48 and 49 and pipe 50, and also through the plate openings 15, to chamber 17. When, however, the piston 33 is in advanced position, the former escape passages are closed oil and at this time the revert gases may pass upwardly betwezn the cylinders it) and 11 into the chamber 2S and from thence through passages 15 into chamber 17. While, as stated, the piston automatically seals the entrance to the revert boxes 48 and 49, when the piston is on its forward stroke, the cold revert gas may nevertheless pass around the bottom edge of the cone and up through the adjustable slots 15 into the space 7 above the dividing flange or plate 14 and such flow may be controlled by the adjustable screws 16 controlling slots or passages 15. As shown best in FIGS. 4 and 5a, the lower end of the tower 11 is slightly shorter than the cylinder 1%, leaving a space through which cold revert gas may pass from the lower portion of the tower into the restricted passage 15.

As stated earlier, the sudden release of pressure within the snow cone 11 is of great importance in causing the quick release of snow from the cone and the deposit of the same within the compression cylinder B. As the piston 38 is advanced during the compression step toward the gate or closure plate 3%), revert gas can no longer escape through the release boxes and conduit 58 into the upper cylinder chamber 17, but instead high pressure is built up within the lower cylinder chamber 28 as well as Within the chamber of cone 11, so that a relatively high pressure, say, in the neighborhood of twenty pounds, is thus built up within the cone chamber and a similar pressure within the chamber 28. Now, when the piston 38 is retracted so as to uncover the outlet from the cone, the revert gases pass through pipe 50 into the lower pressure chamber 17 and there is a sudden lowering of pressure within the cone chamber and within the chamber 28 through the release of revert gas and the flowing of the same back to chamber 17 and also by the retracting of piston 38. As a result, there is a drop in pressure within the cone chamber to, say, two or three pounds, and this sudden release of pressure, in conjunction with the other elements hereto-fore described, causes the snow within the cone 11 to drop instantly into the compression chamber of cylinder B. In the foregoing operation, the adjustment screws 16 control the restricted conduit 15 connecting chambers 28 and 17 so as to build up the high pressure during the forward stroke of piston 38 within the cone and chamber 28, and thus serve to maintain a substantial differential in pressure between the two chambers.

in starting the machine, it is desired to remove air from it, and this may be accomplished by opening the closure plate 39 slightly and passing CO gas through the machine for a short period of time.

Instead of having pipes 18a and 19 passing through the sides of casing ill, these pipes or tubes may be passed through the head or closure plates of cylinder 10.

It will be understood that it is also desired at times to produce snow for commercial uses where the snow is not compacted, or compacted very slightly. Such a product may be produced continuously in the snow-forming tower and the snow ejected through the discharge end 29 of the cylinder B.

While, in the foregoing specification, I have set forth a single embodiment of the invention in considerable detail for the purpose of illustrating the same, it will be understood that such details of structure and process steps may be varied widely by those skilled in the art without departing from the spirit of my invention.

l claim:

1. in Dry Ice manufacturing apparatus, a vertical column, a rigid cone-shaped tower mounted within said column and providing a revert gas release chamber between it and said column, a coil within said chamber extending about said cone for circulating relatively warm liquid CO about said cone, means for releasing said circulated CO in the top portion of said tower to form snow, an angularly-related compression cylinder communicating with the lower larger end of said tower and having a discharge end, movable means for closing the discharge end of said cylinder, a revert gas release conduit leading from said cylinder to said gas release chamber, a compressor piston mounted in said cylinder opposite said discharge end, means for moving said piston toward the closed end of said cylinder for compressing snow into Dry Ice, for closing said conduit and for raising the pressure in said tower, and means for retracting said piston to open said conduit and to release said pressure in said tower whereby snow within said tower is quickly released during said return movement of the piston, said column and cone tower providing a restricted passage therebetween oommunicating with a central port-ion of said cylinder for supplying a restricted amount of revert gases to said chamber when said first-mentioned conduit is closed by said piston and said restricted passage also communicating with the lower portion of said tower.

2. The structure of claim 1 in which said movable closure means is adapted to engage an ice cake formed in said cylinder and includes a piston engaging the end of the ice cake and in which means are provided for holding said piston in contact with the end of said cake as it it being withdrawn from the cylinder.

3. In Dry Ice manufacturing apparatus, a vertical column, a rigid cone-shaped tower mounted within said column and spaced therefrom to provide a revert gas release chamber, a coil within said chamber extending about said cone for circulating relatively warm liquid CO about said cone, means for releasing said circulated CO in the top portion of said tower to form snow, a compression cylinder having a central portion thereof communicating with the bottom larger end portion of said tower and said column, said cylinder having a discharge end, a compressor piston mounted for reciprocation in said cylinder toward and away from said discharge end, movable means for closing the discharge end of said cylinder, a revert gas release conduit providing communication between said cylinder and said chamber, means for moving said piston toward the closed end of said cylinder in the compressing of snow into Dry Ice thus raising the pressure in said tower and closing said release conduit, and means for retracting said piston to open said release conduit and to release the pressure in said tower whereby snow formed with said tower is released into said cylinder, said column and cone tower providing a restricted passage therebetween communicating with a central portion of said cylinder for supplying a restricted amount of revert gases to said chamber when said first-mentioned conduit is closed, said restricted passage also communicating with the lower portion of said tower.

4. The structure of claim 3 in which threaded adjustment means are provided for controlling flow through said restricted passage.

5. The structure of claim 3 in which said reciprocating piston is provided at its snow-engaging end with a resilient release surface.

6. The structure of claim 5 in which said surface is formed of leather.

7. In Dry Ice manufacturing apparatus, a vertical column, a rigid cone-shaped tower mounted within said column and providing therewith a revert gas release chamber, a warming coil in said chamber and extending about said cone for circulating liquid CO means for releasing said circulating CO in the top portion of said tower to :form snow, an angularly-related compression cylinder communicating with the lower and larger end of said tower and column and having a discharge end, a compressor piston mounted in said cylinder, movable means vfor closing the discharge end of said cylinder, a conduit establishing communication between said cylinder and chamber, means for reciprocating said piston toward and away from the closed end of said cylinder in the compressing of snow, for closing and opening said conduit, and for raising and lowering the pressure in said tower, sai-d column and tower providing also a restricted passage between said cylinder and chamber .for supplying a restricted flow of revert gas to said chamber when said conduit is closed by said piston, said restricted passage also communicating with the lower portion of said tower and control means for said movable closure means for opening said cylinder and including a piston, fluid pressure means for reciprocating said last-mentioned piston, a pipe supplying pressure fluid to said pressure fluid means, and a restrictor valve in said pipe for maintaining said last-mentioned piston in contact with the Dry Ice as it is being removed from cylinder.

8. The structure of claim 7 in which an indicator rod is actuated by the compression piston means for visually indicating the size of the Dry Ice block formed by the compression piston.

References Cited in the file of this patent UNITED STATES PATENTS 1,795,772 Goosman Mar. 19, 1931 1,870,691 Rust et al Aug. 9, 1932 1,920,526 Rudd Aug. 1, 1933 1,949,179 Pierce Feb. 27, 1934 1,981,676 Stapp Nov. 20, 1934 1,989,873 Marcus et a1 Feb. 5, 1935 2,016,815 Gilmore Oct. 8, 1935 2,025,698 Cole Dec. 24, 1935 2,145,096 Schutz Jan. 24, 1939 2,151,855 Kobold Mar. 28, 1939 2,282,460 Dickey May 12, 1942 FOREIGN PATENTS 433,018 Great Britain Aug. 7, 1935 678,330 France Dec. 23, 1929

Claims (1)

1. IN DRY ICE MANUFACTURING APPARATUS, A VERTICAL COLUMN, A RIGID CONE-SHAPED TOWER MOUNTED WITHIN SAID COLUMN AND PROVIDING A REVERT GAS RELEASE CHAMBER BETWEEN IT AND SAID COLUMN, A COIL WITHIN SAID CHAMBER EXTENDING ABOUT SAID CONE FOR CIRCULATING RELATIVELY WARM LIQUID CO2 ABOUT SAID CONE, MEANS FOR RELEASING SAID CIRCULATED CO2 IN THE TOP PORTION OF SAID TOWER TO FORM SNOW, AN ANGULARLY-RELATED COMPRESSION CYLINDER COMMUNICATING WITH THE LOWER LARGER END OF SAID TOWER AND HAVING A DISCHARGE END, MOVABLE MEANS FOR CLOSING THE DISCHARGE END OF SAID CYLINDER, A REVERT GAS RELEASE CONDUIT LEADING FROM SAID CYLINDER TO SAID GAS RELEASE CHAMBER, A COMPRESSOR PISTON MOUNTED IN SAID CYLINDER OPPOSITE SAID DISCHARGE END, MEANS FOR MOVING SAID PISTON TOWARD THE CLOSED END OF SAID CYLINDER FOR COMPRESSING SNOW INTO DRY ICE, FOR CLOSING SAID CONDUIT AND FOR RAISING THE PRESSURE IN SAID TOWER, AND MEANS FOR RETRACTING SAID PISTON TO OPEN SAID CONDUIT AND TO RELEASE SAID PRESSURE IN SAID TOWER WHEREBY SNOW WITHIN SAID TOWER IS QUICOLY RELEASED DURING SAID

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