US2901891A

US2901891A - Method and apparatus for preserving perishable material

Info

Publication number: US2901891A
Application number: US564537A
Authority: US
Inventors: Willard L Morrison
Original assignee: Union Stock Yard & Transit Co Chicago
Current assignee: Union Stock Yard and Transit Co
Priority date: 1956-02-09
Filing date: 1956-02-09
Publication date: 1959-09-01
Anticipated expiration: 1976-09-01

Description

P 1959 w. MORRISON 2,901,891

METHOD AND APPARATUS FOR PRESERVING PERISHABLE MATERIAL Sept. 1, 1959 w. L. MORRISON METHOD AND APPARATUS FOR PRESERVING PERISHABLE MATERIAL Filed Feb. 9, 1956 FIGZ 2 Sheets-Sheet 2 III I I III]! III INVENTOR.

WILLARD L.MORRISON BY PARKER &CARTER ATTORNEYS United gtates Patent F NIETHOD AND APPARATUS 'FOR PRESERVING PERISHABLE MATERIAL Application February 9, 1956, Serial No. 564,537

'13 Claims. (Cl. 62'60) My invention relates to improvement in method of and apparatus for preserving by cooling such perishable materials as foodstuifs and the like and has for one object to provide a production line method whereby such materials may be rapidly and effectively frozen or substantially reduced in temperature.

' My invention is especially, though not exclusively, applicable to a situation where it is desired to cool already frozen foodstuffs to temperatures far below the normal freezing temperatures, that isto temperatures far belowv zero degrees F.

I' propose to cool the material being treated by direct contact with a cold, dry gas in gaseous phase, for example, nitrogen which at atmospheric presure does not enter the liquid phase until a temperature in the order of 320 F. has been reached.

Nitrogen is a suitable gas for this purpose because it may directly contact the foodstuffs being treated Without deleterious effect though any other gas Which may be cooled down to low temperature without liquefaction and can contact foodstutfs and the like without deleterious eflect may well be used, for example, argon, helium or other gases.

By direct contact, I mean that the gas may be allowed to contact whatever usual container or Wrapper is pro vided. No special gas-tight or gas resisting metal or other containers being needed to protect the material against contact with the gaseous coolant.

I propose to move a sequence of open mouthed insulated shipper containers through a series of step by step stations. At one station the container may be filled with material to be chilled. At the next station, it will be precooled, at each of one or more intermediate stations, the temperature will be further reduced until when the desired minimum temperature has been reached, the container will be closed for storage or shipment. The particular mechanism for moving the container step by step from station to station form no part of-the present invention and are not illustrated.

' Other objects will appear from time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein Figure 1 is a perspective of the apparatus;

Figure 2 is a section along the line 2--2 of Figure 1.

Like parts are indicated by like characters throughout the specification and drawings.

A cold gas supply duct is indicated at 1. It discharges through an expanding nozzle 2 into a gas distribution box 3, open at top and bottom, adapted to be closed at the top by aremovable lid 4 and in register at bottom with a shipper container 14. A duct 5 joins the box 3 'with a similar box 7. A duct 8 joins the box 7 to a similar box 9, and a contracting nozzle 12 discharges gas through a pipe 13 to receiver 10. Each of the boxes 7 and 9 may be closed by a lid 4 just as is box 3 and that lid will also fit and may be installed to close any of the insulated shipper Patented Sept. 1, 1959 ice containers 14, when they are not associated with the gas distribution boxes 3, 7 and 9.

I have illustrated a number of separate stations. The station occupied by the box 3, I prefer to call the superchill station. The station occupied by the box 7 the intermediate station and that occupied by the box 9 the initial chilling station.

Assuming that a lid 4 closes the upper open face of each of the boxes 3, 7 and 9, the four shipper containers associated with those boxes may be raised upwardly by platens 15 supported by plungers 16 actuated by hydraulic cylinders 17 so that each shipper container is brought into contact with the under open face of its associated gas distribution box. When cold gas is forced into box 3 from pipe 1, it circulates from box to box to discharge through pipe 13, the gas is warmed as it passes from shipper container to shipper container, the contents of the shipper containers being correspondingly chilled.

Each shipper container is supported by the conveyor belts 18 traveling along rollers 19 which as shown in Figure 1 rotates in a counter clockwise direction and held in position on the belts by cleats 20 so that as the belt moves forward one step, each shipper container is brought into register with the platen 15 associated with the next cooling station. Shipper container 14 may be placed on the belts at the feed end of the system. It may be filled with material to be chilled as indicated at 21 either before or after it is placed on the belt and this may be done either manually or mechanically as desired. 14" will, at the discharge end or" the system, be closed prior to removal by one of the lids or covers 4.

When the shipper container 14 has moved forward into register with the box 9, the cover 4 is placed on the box and the shipper container brought into engagement with the underside of the box, the gas precools the contents of the shipper container and also the under surface of the cover. When the shipper container is moved into register with the box 7, the cover is moved forward in register with the box 7, the same thing happens when the shipper container register with the box 3 and thereafter the container is discharged in proper cooled condition having passed through the various cooling stations. The cover which has traveled with each container and which has been chilled accordingly will be placed on the shipper container which is then closed for storage and shipment.

The gas which picked up heat as it travels from stage to stage in boxes 3, 7 and 9 but still, of course, is quite being circulated as a coolant and will be so small in quan-' cold gas, is discharged from receiver 10 to enter a gas to gas heat exchanger 22. The pipe 23 conducts the gas to a first stage compressor 24 where it is compressed and raised in temperature. The gas passes through the duct 25 to a water cooler 26 which extracts the heat of compression. The gas then goes through the duct 27 to the second stage compressor 28 where it is compressed and warmed and discharged to a Water cooler 30, thence through a duct 31 to the gas to gas heat exchanger 22 where the gas at higher pressure, the heat of compression having been extracted by the water coolers is further cooled so that when it is discharged through the pipe 32 from the heat exchanger 22, it may expand and do work in the expander 33 for discharge as cold gas through the pipe 1 back to the cooling heads or boxes.

A motor 34 furnishes the additional power needed to operate the system. Water connections 35, 36 provide cold Water circulation through the

Water coolers

26 and 30.

As each successive shipper container filled with the food or other material to be chilled comes in register with the prechilling gas distribution box or cooling head, it will contain some air. That air will be in very small quantity in proportion to the volume or weight of the gas tity that it can be disregarded even though there may result a slight dilution of the coolant gas. Each time a new container is added to the system, this happens and finally after the dilution has reached a dangerous point, the nitrogen may be discharged and a new supply will replace it.

The circulation of the gas will take place only during the time that the shipper containers are in the raised position, brought snugly up against the under side of the gas distribution boxes. Before the shipper containers are lowered to the belt for movement to the next step, circulation will be stopped by turning off the power on the motor 34 and circulation will start again when the system is again closed.

The gas used for refrigeration according to my invention is very much colder than the ambient air in the shipper container and at each station is very much colder than the gas or air contained within the shipper container. Such cold gas always rapidly seeks a lower level, expelling the lighter warmer gas. Packages of foodstuff and the like are always more or less irregular in shape. They are frequently of wood or fiber board and they cannot be packed together tightly. Thus there is always substantial clearance between and about the packages through which such cold gas may sink as it tends to expel the warmer gas. Th-us step by step the gas is warmed and the contents of the shipper containers is chilled until at the end of the cycle the contents of the shipper container at the superchill station has reached the low point desired for shipment.

A receiver 10, preferably of variable capacity is in the line between the final pre-cooled box 9 and the gas to gas heat exchanger 22 to permit expansion and contraction of the gaseous volume of the system depending upon change in temperature and depending upon whether or not the motor 34 is operating. Suitable control valves not here illustrated, since they form no part of the present system may be used in consonance with the stopping and starting of the motor. The electric controls for stopping and starting the motor 34 forming no part of the present invention are also not here illustrated.

I claim:

1. Means for chilling foodstuffs and the like comprising a plurality of insulated shipper containers, means for moving them in unison step by step from a precooling to a superchilling station, a separate gas distribution box at each station in register and in communication with the container at such station, means for circulating cold gas through said boxes in series in a direction opposite to the step by step movement of the shipper container, means for discharging the warmed gas from the last of said boxes, recooling it and supplying it to the first of said boxes in the series, means for connecting the boxes in series, said means conducting all the gas from one box into the next in the series.

2. Means for chilling foodstuffs and the like comprising a plurality of insulated shipper containers, means for moving them in unison step by step from a precooling to a superchilling station, a separate gas distribution box at each station in register and in communication with the container at such station, means for circulating cold gas through said boxes in series in a direction opposite to the step by step movement of the shipper container, means for discharging the warmed gas from the last of said boxes, recooling it and supplying it to the first of said boxes in the series, means for connecting the boxes in series, said means conducting all the gas from one box into the next in the series, conveying means adapted to support the shipper containers, means associated with each station for lifting the shipper at.

such station from the conveying means and holding it in register with the box at such station.

3. Means for chilling foodstufis and the like comprising a conveyor, a plurality of insulated shipper conadapted to be supported on and carried by said.

conveyor, means for positively positioning each shipper container in spaced longitudinal relationship with the others on the conveyor, a plurality of separate gas dis tribution boxes spaced along the conveyor and defining a plurality of cooling stations, means at each station for elevating each shipper container from the conveyor and holding it in register with and in communication with the box at that station, means for circulating cold gas through said boxes and the shipper containers in series at the successive stations.

4. Means for chilling foodstuffs and the like comprising a conveyor, a plurality of insulated shipper containers adapted to be supported on and carried by said conveyor, means for positively positioning each shipper container in spaced longitudinal relationship with the others on the conveyor, a plurality of separate gas distribution boxes spaced along the conveyor and defining a plurality of cooling stations, means at each station for elevating each shipper container from the conveyor and holding it in register and in communication with the box at that station, means for circulating cold gas through said boxes and the shipper containers in series at the successive stations, a cover for each shipper container, the cover being adapted to register with and close the shipper container after it has left the last station and to close and be cooled by the gas circulating through the box associated with each of the shipper containers.

5. Means for chilling foodstuffs and the like com-. prising a plurality of insulated shipper containers, a plurality of cooling stations, means for placing each shipper container step by step in register with each of the cooling stations, means for circulating cold gas through each of the cooling stations in sequence whereby the contents of the containers are step by step cooled, there being a removable cover for each of the insulated shipper containers, the covers being adapted to be placed in register with the successive cooling stations as the associated shipper container moves step by step into register with each of the cooling stations whereby the cover associated with each shipper container is cooled in consonance with the cooling of the contents of the shipper container, each cooling station including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be. placed on and close the top of the box whereby the. covers are cooled by the cold air entering the shipper container.

6. Means for chilling foodstuifs and the like com-. prising a plurality of insulated shipper containers arranged in sequence and each open at the top, a gas distribution box open to and in register with and closing the. open top of each shipper container, means for supplying cold gas to the first distribution box in the sequence, means for conducting gas from each distribution box to the next in the sequence, means for withdrawing the gas from the last box in the sequence.

7. Means for chilling foodstuffs and the like comprising a plurality of insulated shipper containers arranged in sequence and each open at the top, a gas distribution box open to and in register with and closing the open top of each shipper container, means for supplying cold gas to the first distribution box in the sequence, means for conducting gas from each distribution box to the next in the sequence, means for withdrawing the gas from the last box in the sequence, means for recooling' the gas and returning it to the first distribution box in the sequence.

8. Means for chilling foodstuffs and the like comprising a plurality of insulated shipper containers ar-t ranged in sequence and each open at the top, a gas distribution hox open to and in register with and closing the open top of each shipper container, means for supplying cold gas to the first distribution box in the sequence, means for conducting gas from each distribution box to? the next in the sequence, means for withdrawing the gas;

from the last box in the sequence, each of the distribution boxes being open at the bottom in register with its associated shipper container and open at the top, there being covers for each shipper container, the covers being adapted to close the open top of the distribution box whereby the gas passing through the distribution box into and out of the shipper container simultaneously cools the cover associated with each respective shipper container.

9. Means for chilling foodstuffs and the like comprising a plurality of gas distribution receptacles, a compressor expander, gas chilling apparatus arranged in series with the gas distribution receptacles, means for propelling step by step into register with successive gas chilling receptacles a plurality of open topped shipper containers, means for successively presenting said containers to the gas distribution boxes in series whereby the cold gas is supplied to the first box, passes from it to the other boxes in series and is Withdrawn for recompression, expansion and cooling, each cooling st-ation including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be placed on and close the top of the box whereby the covers are cooled by the cold air entering the shipper container.

10. Means for chilling foodstuffs and the like comprising a plurality of gas distribution boxes open at bottom arranged in sequence, means for supplying cold gas to the first box in the sequence, means for conducting gas from each box to the next in the sequence and means for discharging gas from the last box of the sequence, a plurality of insulated shipper containers open at the top, means for successively placing each of the shipper containers in register with the open bottom of a gas distribution box whereby gas from the box may flow by gravity into and fill such shipper container, each cooling station including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be placed on and close the top of the box whereby the covers are cooled by the cold air entering the shipper container.

11. Means for chilling foodstuffs and the like comprising a plurality of gas distribution boxes open at the bottom arranged in sequence, means for supplying cold gas to the first box in the sequence, means for conducting gas from each box to the next in the sequence and means for discharging gas from the last box of the sequence, a plurality of insulated shipper containers open at the top, means for successively placing each of the shipper containers in register with the open bottom of a gas distribution box whereby gas from the box may flow by gravity into and fill such shipper container, the open bottom of the distribution box being substantially coextensive with and in substantially gas-tight contact with the open top of the shipper container, each cooling station including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be placed on and close the top of the box whereby the covers are cooled by the cold air entering the shipper container.

12. Means for chilling foodstufis and the like comprising a plurality of gas distribution boxes open at top and bottom arranged in sequence, means for supplying cold gas to the first box in the sequence, means for conducting gas from each box to the next in the sequence and means for discharging gas from the last box of the sequence, a plurality of insulated shipper containers open at the top, means for successively placing each of the shipper containers in register with the open bottom of a gas distribution box whereby gas from the box may flow by gravity into and fill such shipper container, there being a plurality of shipper container covers each adapted to close the open top of a gas distribution box, each cooling station including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be placed on and close the top of the box whereby the covers are cooled by the cold air entering the shipper container.

13. Means for chilling foodstuffs and the like comprising a plurality of gas distribution boxes open at top and bottom arranged in sequence, means for supplying cold gas to the first box in the sequence, means for conducting gas from each box to the next in the sequence and means for discharging gas from the last box of the sequence, a plurality of insulate-d shipper containers open at the top, means for successively placing each of the shipper containers in register with the open bottom of a gas distribution box whereby gas from the box may floW by gravity into and fill such shipper container, there being a plurality of shipper container covers each adapted to close the open top of a gas distribution box, the open bottom of the distribution box being substantially coextensive with and in substantially gas-tight contact with the open top of the shipper container, each cooling station including a frame adapted to register with the shipper container and rest thereupon, open at the bottom in register with the shipper container, a cover associated with each shipper container adapted to be placed on and close the top of the box whereby the covers are cooled by the cold air entering the shipper container.

References Cited in the file of this patent UNITED STATES PATENTS 1,994,233 Shaw Mar. 12, 1935 2,077,608 Wood Apr. 20, 1937 2,237,257 Finnegan Apr. 1, 1941 2,527,542 Gilson Oct. 31, 1950