US 3096627 A
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July 9, 1963 w. L. MORRISON 3,096,627
APPARATUS FOR QUICK FREEZING OF BAKERY GOODS INVENTOR. Wax/M01. Mafia/Jo BY finkkekgdnerse Arron/ave July 9, 1963 w. L. MORRISON 3,096,627
APPARATUS FOR QUICK FREEZING OF BAKERY GOODS Filed July 14, 1960 2 Sheets-Sheet 2 own/r0? MZLARO z JIQQFAS'OI/ United States Patent M freeze Company, Inc., New York, N.Y., a corporation of New York Filed July 14, 1960, Ser. No. 42,937 Claims. (Cl. 62-178) This invention relates to improvements in method and apparatus for quick freezing food and the like down to a point far below zero degrees F. in a matter of minutes rather than hours.
It is well adapted to the freezing of bakery goods and the like in the cartons in which otherwise unwrapped bakery goods are shipped. It is especially well adapted to the freezing of bread, cake and the like in the sales carton so the product may be packed ready for shipment and sale before freezing and may after freezing be further shipped without further packaging.
Another object of the invention is to use the carton which contains the food. It may be perforate or liquid permeable as the case may be, as a part of the apparatus to inhibit waste of coolant and also to inhibit entrance of ambient air into the cooling area as the product enters and leaves the cooling area.
In general, I propose to pack cakes, bread, rolls and the like in the paper or cardboard carton in which they are usually packed. The carton will normally be porous and pervious to liquid and frequently perforate to permit entrance and exit of liquid into the car-ton. When the food is placed in the carton, the carton will then be fed into a freezing zone where it will normally be first exposed to cold gaseous coolant, preferably nitrogen, at atmospheric pressure, will then be immersed in a bath of the liquid, preferably liquid nitrogen at atmospheric pressure, will thereafter after complete freezing, be withdrawn through the bath, pass through an atmosphere of the gaseous coolant and discharged in frozen condition. The carbons in which the food is packed, as they enter and leave the cooling area where they are exposed to the gas before they enter the bath, serve as a continuous running closure to inhibit the escape of gas or entrance of air. It will be understood that the method and apparatus I propose might equally Well be used for freezing other articles. An important factor is that after cooling down to the desired low temperature, the material cooled is ready for shipment without cartonizing, packaging or other treatment.
Other objects will appear from time to time throughout the specification and claims.
The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein FIGURE 1 is a perspective in part section with parts omitted showing my invention;
FIGURE 2 is a section along the line 2-2 of FIG- URE 1;
FIGURE 3 is a diagrammatic view with parts omitted of a modified form of part of the device of FIGURE 1.
Like parts are indicated by like numerals throughout the specification and drawings.
The insulated housing 1 is provided at one end with an adjustable gas lock 2. A table 3 carries a belt conveyor 4 which discharges a carton 5 onto a conveyor belt 6 in the gas lock 2. The carton may be perforate, may be liquid pervious or both in order that the liquid in which the carton is to be immersed will enter the carton to contact the contents therein and will freely leave the carton to avoid wasting as the carton leaves the liquid bath. The gas lock 2 is lined top and both sides with removable bristle or brush or fiber carrying fillers 3,096,627 Patented July 9, 1963 7. Any suitable flexible, expandable, contractable means may be associated with these fillers, the sole requirement being that it conforms to the size and contour of the fillers to inhibit gas flow around the carton. Bristles which engage the carton 5 are especially effective for this pur pose, even a rubber diaphragm might be used. The conveyor belt 6 is associated with a central fixed filling plug 8 and bristles 9 to inhibit air flow about the conveyor 6. The belt 4 travels at a higher speed than the belt 6 so that as successive cartons are brought up by belt 4 they are pressed against the cartons on belt 6 so as to form a continuous column :of cartons passing into and through the gas lock 2. Each carton as it leaves the belt 6 comes in contact with an upper belt 10 and a lower belt 11, which belts are guided by rollers 12 so that the carton gripped between them is carried downwardly into a liquid nitrogen bath in the bath tank 13. The belt 10 on its return passes above the tank 13. The belt 11 passes below it over the rollers as indicated.
Because the cartons are perforate, when the carton is immersed in the liquid nitrogen bath at atmospheric pressure and 320 degrees F., the liquid nitrogen comes into immediate contact with the bakery goods, wets the entire periphery of each piece and freezes it down to a temperature far below zero degrees F. As the carton leaves the bath at the discharge end of the housing, any nitrogen in the carton drains out and returns to the bath. Each carton then is discharged onto aramp 14 and is propelled by the belt conveyor 15 through the discharge gas lock 16 for discharge onto the table 17. The structure of the intake and discharge gas locks are the same and a description of one will do for both.
An electric eye '18 controls valves 19 and 20- in the feed gas lock. Normally valves 19, 20 are closed unless cartons are passing through. When a carton 5 approaches the eye 18, a switch controlled thereby opens the valve .19 so the carton 5 may enter the gas lock. As long as the cartons present themselves, that valve stays open. A delayed action relay causes valve 20 to also open as soon as the first carton 5 has entered the gas lock and as long as cartons keep coming, one in contact with the next, these valves stay open and the cartons are free to go through the system.
An electric eye 23 similar to the eye 18 except it is inside the cold chamber opens the valve 22 as a carton approaches the discharge lock and by delayed action the valve 21 also opens. These valves remain open as long as cartons keep coming but as soon as electric eye 23 senses absence of cartons, first valve 22 and then valve 21 closes. Thus the system is always closed when not in operation.
The removable filler blocks 7 in both of the air locks are removable and interchangeable. Different thicknesses may be used to compensate for different sizes of carton and this may be done without any interference with the valves or shutters 19, 20, 21 and 22.
The lower belt 11 is mounted on a fixed frame and is not adjustable but the upper belt 10 is mounted on an adjustable frame 24 and may be moved up and down, toward and from the belt 11 to compensate for cartons of difi-erent thickness. Adjusting screws 25 may be manipulated to accomplish this adjustment.
Liquid nitrogen comes in from a suitable source of trogen, preferably a reliquefier, through the duct 26 into the housing and down to the bath vessel 13. As the carton and its contents is immersed in the bath, the gas boiled off by the heat valve, passes through the discharge conduits 27 to the reliquefier. The details of the reliquefier form no part of the present invention and are not therefore illustrated.
It is important first that the gas locks in adjustable in size to insure that no matter what size within a reasonable range the carton takes, there will be a gas flow inhibiting fit between the carton and the bristle carried by the fillers 7. Once the carton has been discharged into the cold chamber from the gas lock, it is essential that the distance between the belts and 11 be such as to insure that each carton is fed below the level of the bath and each carton is conveyed positively through the bath for discharge therefrom.
Under ordinary circumstances the carton sizes will vary but slightly and the flexibility of the cartons plus the simple adjustment of the screw will be quite adequate to compensate for such size variations. However, in the event that large size variation occurs, it will require the use of substantially different size fillers 7 and will require a different method of adjusting the distance between the belts 10 and 11. A convenient solution of this problem is shown in FIGURE 3 illustrating only the support of the belt 10.
The belt 10 is supported on A-frames outwardly and downwardly inclined as indicated, supported at their upper ends by nuts 31 in sleeves 32. The lower apices of the A-frames support a rib 33 slotted at both ends as at 34 to be in sliding engagement with pivot pins 35 at the apices of the A-frames. Webs 36 extend outwardly from the A-frames and carry rollers 37. Similar rollers 37 are carried by the rib 33. Pulleys 38 are pivoted on the pins 35. A belt 39 travels about the pulleys 40 at the upper, outer apices of the A-frame and about pulleys 41 which are free to rotate and slidably mounted in slots 42 in the A-frames. By this arrangement when the A-fnarnes 30 are retracted, the belt 39 raises above the belt 11 and always withdraws inwardly from the inclined portions of the belt 11, thus maintaining the distance beween the two belts the same. The weight of the rollers or pulleys 41 since they are free to move vertically in the frame maintains the belt tight independent of the inclined upward or downward movement of the two A-frames.
Under ordinary circumstances, it is highly desirable to have the package as indicated, a light, more or less flexible carton contacted with belt above and below to insure proper positioning and proper flow of the ifoodstufi? through the cooling zone. Under some circumstances one or other of the belts might be omitted. If the specific gravity of the material being cooled is greater than the specific gravity of the liquid, the material Will sink to the bottom of the bath and could be supported on a lower belt. On the other hand, if the specific gravity of the material being treated is less than that of the liquid, it must be held under the level of the bath by a belt or other suitable means in order that the entire material receive its treatment.
1. In combination, an insulating housing, a bath of liquid nitrogen therein, a pair of opposed conveyors contained entirely within the housing, generally parallel to one another, means for guiding them along spaced inclined paths downwardly below the level of the bath at one end, horizontally through the bath and upwardly above the level of the bath at the other end, means for positively adjusting the distance between the horizontal conveyor paths and means responsive thereto for maintaining the distance between the downward and upward paths the same as the distance between the horizontal paths.
2. In combination, an insulating housing, a bath of liquid nitrogen therein, a pair of opposed conveyors contained entirely within the housing, generally parallel to one another, means for guiding them along spaced inclined paths downwardly below the level of the bath at one end, horizontally through the bath and upwardly above the level of the bath at the other end, means for positively adjusting the distance between the horizontal conveyor paths and means responsive thereto for maintaining the distance between the downward and upward paths the same as the distance between the horizontal paths, said means including a pair of inclined A-frames, rollers and pulleys carried thereby along which the conveyors travel and means for displacing said A-frame along inclined lines, bisecting the angle between the inclined path and the horizontal.
3. A gas lock including a tunnel, means for propelling packages of food therealong, flexible, closely packed, setaceous brush bristle sealing means fixed on, distributed along and projecting inwardly from the tunnel walls to contact food packages and close the clearances about each package as it passes along the tunnel, the bristles being free to bend in the direction of package travel.
4. A gas lock including a tunnel, means for propelling packages of food therealong, flexible, closely packed, setaceous brush bristle sealing means fixed on, distributed along and projecting inwardly from the tunnel walls to contact food packages and close the clearances about each package as it passes along the tunnel, the bristles being free to bend in the direction of package travel, the propelling means including a belt conveyor coextensive adjacent one wall.
5. A gas lock including a tunnel, means for propelling packages of food therealong, flexible, closely packed, setaceous brush bristle sealing means fixed on, distributed along and projecting inwardly from the tunnel walls to contact food packages and close the clearances about each package as it passes along the tunnel, the bristles being free to bend in the direction of package travel, valves adapted to open and close the opposite ends of the tunnel, automatic means responsive to the presence of a carton for opening and closing said valves.
References Cited in the file of this patent UNITED STATES PATENTS 84,904 Reed et al Dec. 15, 1868 890,252 Thompson June 9, 1908 1,944,857 Atwell Jan. 23, 1934 2,286,514 Stebbins June 16, 1942 2,313,606 Webb et al. Mar. 9, 1943 2,563,184 Naylor Aug. 7, 1951 2,614,403 Heise Oct. 21, 1952 2,642,178 Naylor June 16, 1953 2,951,353 Morrison Sept. 6, 1960 2,977,106 Duff Mar. 28, 1961