US3818719A - Refrigerating apparatus - Google Patents

Abstract

An apparatus for refrigerating, either freezing or chilling, articles and particularly food items using an improved distribution system for distributing the fluid cryogen uniformly across a refrigerating chamber that has an entrance, an exit and a conveyor for moving the articles in a path between the entrance and the exit. The distribution system comprises a cryogen supply duct to the chamber, a nozzle device for ejecting a stream of cryogen into a supply duct and a deflector at an angle to the stream for intercepting and dispersing the stream across the duct and thereby across the width of the chamber.

Description

United States Patent [191 Banike REFRIGERATING APPARATUS [75] Inventor: Ronald A. Banike, Elmhurst, ll]. [73] Assignee: Integral Process Systems, Inc., Park Forest, Ill.

[22] Filed: Mar. 8, 1973 [21] Appl. No.: 339,396

[52] U.S. Cl. 62/374, 62/380 [51] Int. Cl. F25d 17/02 [58] Field of Search 62/378, 380, 374, 375, 62/376, 63

[56] References Cited UNITED STATES PATENTS 3,254,506 6/1966 Braeking. 62/380 X 3,708,995 l/l973 Berg June 25, 1974 Primary Examiner-Meyer Perlin Assistant Examiner-Ronald C. Capossela Attorney, Agent, or Firm-Hofgren, Wegner, Allen, Stellman & McCord 5 7] ABSTRACT An apparatus for refrigerating, either freezing or chilling, articles and particularly food items using an improved distribution system for distributing the fluid cryogen uniformly across a refrigerating chamber that has an entrance, an exit and a conveyor for moving the articles in a path between the entrance and the exit. The distribution system comprises a cryogen supply duct to the chamber, a nozzle device for ejecting a stream of cryogen into a supply duct and a deflector at an angle to the stream for intercepting and dispersing the stream across the duct and thereby across the width of the chamber.

5 Claims, 7 Drawing Figures PATENTEB JUN 2 a EB'M SHEET 2 (IF 2 l REFRIGERATING APPARATUS BACKGROUND OF THE INVENTION One of the features of this invention is to provide an improved apparatus for refrigerating articles having a chamber through which the articles are passed during the refrigerating and an improved means for introducing the cryogen into the chamber in an even distribution'across the width thereof including a supply duct to the chamber, a nozzle for ejecting a stream of the fluid cryogen into the duct and a deflector at an angle to the stream for intercepting and breaking up and dispersing the stream from the nozzle across the width of the duct and thereby across the width of the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS 7 FIG. 1 is a side elevational view of an apparatus embodying the invention.

FIG. 2 is a longitudinal vertical sectional view taken substantially through the center of the apparatus of FIG. 1.

FIG. 3 is a fragmentary horizontal sectional view through the apparatus in the vicinity of the gas recirculation blower.

FIG. 4 is an end elevational view taken from the left or exit end of FIG. 1.

FIG. 5 is a view similar to FIG. 4 but taken from the opposite end of the apparatus.

FIG. 6 is an enlarged sectional view partially in side elevation and partially broken away taken substantially along line 66 of FIG. 1.

FIG. 7 is an enlarged sectional view partially in side elevation and partially broken away taken substantially along line7--7 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus of this invention has structural and operational features disclosed in the copending Richard C. Wagner applications Ser. No. 264,133, filed June 19, 1972, and Ser. No. 339,395, filed Mar. 8, 1973 which is a continuation-in-part of the earlier application, both applications being assigned to the same assignee as the present application.

In the embodiment of the apparatus 10 disclosed in the accompanying drawings there is provided an elongated thermally insulated chamber 11 comprising a series of end-to-end subchambers 12 each with thermally insulated walls as shown in FIG. 2 and insulated hinged lids 13. The subchambers 12 are releasably latched together in end-to-end relationship by latches 14 while the lids 13 are normally latched closed by latches 15.

As shown in FIG. 5 each lid 13 can be raised for servicing and cleaning the interior of the chamber or tunnel 11 by means of air cylinder and piston structures 16 positioned along one side of the chamber or tunnel 11.

The insulated tunnel II has an entrance l7 and an exit 18 ends for conveying articles (not shown) through the tunnel l l as by means of an openwork metal conveyor 19. This conveyor 19 extends beyond the entrance 17 to the tunnel as shown in FIG. 2 and passes over a roller 20 mounted on an extension 21 of the apparatus. The opposite end of the conveyor belt 19 similarly passes over a driven roller 22 that is motor driven in the customary manner by a motor drive identified generally at 23 in FIG. 1. This type of endless open metal conveyor and drive is disclosed in U.S. Pat. No. 3,580,000 owned by the present assignee.

The liquid cryogen used in the illustrated embodiment is liquid carbon dioxide and is supplied to the apparatus 10 from a source (not shown) through a pipe 24 that extends into the insulation 25 leading to a mass of insulation 26 in which is located a gas recirculation blower 27 driven by an external electric motor 28.

The pipe 24 is adapted to have liquid carbon dioxide under pressure circulated continuously in that the pipe includes an inlet 29, a loop 30 within the insulation 26 and an outlet 31 leading back to the source of liquid cryogen. By keeping the liquid circulating continuously there is less chance of the carbon dioxide setting up in the pipe 24 to a solid and thereby stopping the flow.

In order to supply the fluid cryogen to the apparatus there is provided a main on-off control valve 32 which is of a ball valve type operated by an external handle 33. The liquid cryogen is supplied as needed through a combination of an air operated valve that is operated by a valve positioner 35 and a nozzle valve 34. An excellent valve 34 for this purpose is the shear orifice valve disclosed and claimed in my copending application Ser. No. 293,408, filed Sept. 29, 1972, and also assigned to the same assignee as the present application.

In order to show the internal fluid pressure in the valve 34 and thus to note when it is operating properly there is located a pressure gauge 36 on the cabinet wall 37 that contains the insulation 26 for the blower 27.

The valve 34 extends into the recirculation outlet 38 from the insulated blower 27 so as to supply the liquid cryogen at this outlet. The stream of liquid which in this embodiment is liquid carbon dioxide emerges from the valve as indicated at 39 and is directed against a deflector 40 as shown in FIG. 7 which in this embodiment is at a 45 angle to the horizontal with the emerging stream 39 being at less than 45 to the horizontal and therefore less than to the deflector 40.

The distribution system for passing the fluid cryogen into the chamber or tunnel l1 introduces the cryogen uniformly across the width of the chamber and rapidly which is particularly important in the case of a cryogen such as liquid carbon dioxide which rapidly turns to a solid and a gas upon drop in pressure. Thus the means for introducing comprises a supply duct to the chamber 11 which supply duct as illustrated comprises the sideby-side turning vanes 45 (FIGS. 3, 6 and 7) that provide the side-by-side supply passages 83 having thier ends adjacent the deflector 40 close together to provide an entrance portion to the supply duct or passage 83 and exits providing an exit portion to the duct spanning the lateral width of the chamber 11 as shown in FIG. 3. These vanes 45 in the illustrated embodiment turn through 90 from the laterally extending entrance portions to the longitudinally extending exit portions.

In order to distribute the cryogen from the nozzle 34 the deflector 40 is positioned at the entrance to the supply passages 83 at an angle to the stream 39 from the valve 34 for intercepting the stream, breaking it up into diffused portions 84 and dispersing and distributing the resulting broken up stream across the lateral width of the duct at the deflector 40. The angle of the deflector 40 to the valve stream 39 is at an angle greater than 90 and toward the duct as is illustrated in FIG. 7. The supply duct or passage 83 and longitudinally extending chamber 11 are in series with each other from the introducing nozzle 34.

The deflector 40 greatly aids in distributing the fluid cryogen throughout the transverse width 44 of the freezing chamber or tunnel ll uniformly and rapidly even when using a single supply valve 34 as shown. Thus the combination of the single valve 34, the deflector 40 and the 90 turning vanes 45 that are located in a lid 13 as shown in FIG. 7 (described and claimed) in Wagner application Ser. No. 264,133 rapidly and efficiently turn the fluid cryogen 39 from a generally transverse direction relative to the length of the tunnel 11 through 90 to a longitudinal direction toward the tunnel entrance 17.

The valve 32 is connected to a relief valve 4] through tubing 42 and the valve 34 is connected to the pressure gauge 36 by tubing 43. As seen in FIGS. 2, 6 and 7 the turning vanes 45 are positioned in an elevated lid 46 of the group of lids 13.

In order to refrigerate the articles on the conveyor 19 the fluid immediately contacts the articles which may be packages of food to be frozen, spaced meat patties and the like and the contact is by countercurrent flow as illustrated in the disclosed embodiment where the product being refrigerated flows from right to left or from the entrance ]7 to the exit 18 as shown by the arrows 47 while the cryogen flows from left to right as indicated by the arrows 48.

Where the fluid cryogen is liquid carbon dioxide or the like at the point of introduction into the apparatus its passage through a flow valve such as the valve 34 immediately causes it to be converted into a mixture of solid snow and cold gas. The snow falls onto the tops of the articles and to a certain extent between the articles and is then itself converted into a cold gas. As is explained in Wagner application Ser. No. 264,l33 the tunnel includes a final sublimation zone 49 between the cryogen introduction area 38 which coincides with the recirculation outlet 38 and the exit 18 from the tunnel. In this zone 49 there are provided three spaced top mounted fans 50 each driven by an electric motor 51 and directed downwardly to insure sublimation of any solid carried by the articles on the conveyor 19 so that no solid particles are carried from the tunnel.

The cryogen introduction area 38 is spaced from the tunnel entrance l7 and there are provided means for withdrawing the spent cryogen gas at a withdrawal area 52 adjacent the entrance 17. This means comprises a horizontal cylinder 53 having a bottom opening 54 for receiving gas from the entrance l7 and a motor driven blower 55 exhausting the gas upwardly through an exhaust duct 56.

Located within the tunnel 11 adjacent to both the withdrawal area 52 and the conveyor 19 at the entrance 17 to the tunnel is an elongated flow confining baffle 57 that serves to increase the gas velocity in the area 58 beneath the baffle and above the conveyor 19 and the articles carried thereon. In one embodiment of the baffle 57 the bottom 59 was located about 1/2 inch above the tops of the articles carried by the conveyor which in this instance were flat ground meat patties.

The baffle 57 has the additional function of restricting or inhibiting the amount of spent cryogen gas 60 exhausted from the tunnel and also aids in regulating the proportion of the cryogen gas that is recirculated within the apparatus.

As is shown in FIG. 2 the tunnel beneath the conveyor 19 is provided with horizontal plates one of which 61 is located adjacent to the entrance 17 and the withdrawal area 52 and another of which 62 has one end spaced from the plate 61 and the other end extending beyond the cryogen introduction area 38 in the direction of the tunnel exit 18. The spacing of the adjacent ends of the plates 61 and 62 provides an entrance 63 to a bottom reach of a gas recirculation passage 64 that has one horizontal extent beneath the plate 62 and another horizontal extent above the plate 62 so that the gas is recirculated forwardly beneath the plate in the passage 64 and then downwardly in an insulated passage 65 (FIGS. 2 and 6), then horizontally as indicated at 66 and then upwardly as shown at 67 into the recirculation blower 27. From here the recirculated gas is exhuasted by the blower horizontally through the area 38 where it is mixed with incoming fresh fluid cryogen 39 and turned from a transverse to a longitudinal direction as described by the 90 spaced turning vanes 45.

The passage areas 65, 66 and 67 comprise a transverse conduit loop from the bottom of the tunnel and back to the side thereof and into the tunnel by way of the turning vanes 45. In order to provide access to this loop the end of the horizontal passage 66 is provided with a removable plate 68 while the blower housing 78 itself is provided with a duct 69 normally covered by a removable plate 70 and with a bottom drain 79.

As stated earlier, the horizontal baffle 57 with sealed sides adjacent the entrance 17 contributes toward the gas balance between the exhaust 60, the recirculated gas 71 and the incoming fresh fluid cryogen 39 and further aided by top 80 and bottom 81 entrance baffles. In order to provide adjustment to this gas balance there is provided a thermally operated gas balance blade 72 of the type described in the Wagner application 264,133 and a manually adjustable blade 73. The blade 72 is positioned within the tunnel 11 upstream or toward the entrance 27 from the cryogen introduction area 38 and is positioned to engage a stop 74 when in closed position or to the left of its position as shown in FIG. .2. The manual blade 73 as shwon in FIGS. 2 and 6 is positioned at the top of the vertical passage 65 of the transverse gas bypass loop 75 that, as explained earlier, includes the passages 65, 66 and 67.

As is shown in FIGS. 2 and 4 the exit 18 is provided with a top exit curtain 77 that is in the form of individually suspended flexible strips. Immediately beneath this curtain 77 is a downwardly hinged end plate 78.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the appended claims.

I claim:

1. Apparatus for refrigerating articles, comprising: means defining a generally horizontal elongated chamber having an entrance and an exit; conveyor means for moving said articles in the chamber in a longitudinal path from the entrance to the exit; and pressure means for projecting under pressure a fluid cryogen first laterally and then longitudinally into said chamber for contact with said articles at an introduction area of the chamber spaced from said entrance, said means for projecting comprising a cryogen supply duct to said chamber, nozzle means for ejecting a stream of said cryogen at an angle to the horizontal and a deflector means at a complementary angle to said stream and inclined toward said supply duct for intercepting and disdeflector means is located in the corresponding said subchamber.

4. The apparatus of claim 2 wherein said supply duct between its entrance and exit portions is curved smoothly and gradually with said exit extending across the width of said chamber for distribution of said fluid cryogen across said width.

5. The apparatus of claim 4 wherein said supply duct is divided into laterally spaced sections by spaced vanes to provide side-by-side passages having adjacent entrances comprising said entrance portion that is adjacent said deflector means and exits comprising said exit portion spanning substantially the entire width of said chamber.

Claims (5)

1. Apparatus for refrigerating articles, comprising: means defining a generally horizontal elongated chamber having an entrance and an exit; conveyor means for moving said articles in the chamber in a longitudinal path from the entrance to the exit; and pressure means for projecting under pressure a fluid cryogen first laterally and then longitudinally into said chamber for contact with said articles at an introduction area of the chamber spaced from said entrance, said means for projecting comprising a cryogen supply duct to said chamber, nozzle means for ejecting a stream of said cryogen at an angle to the horizontal and a deflector means at a complementary angle to said stream and inclined toward said supply duct for intercepting and dispersing said stream across said duct.

2. The apparatus of claim 1 wherein said supply duct has an entrance portion adjacent said deflector means to receive cryogen from said pressure means and deflector means, said supply duct entrance portion extending laterally of said path and an exit portion extending generally longitudinally of said path.

3. The apparatus of claim 2 wherein said chamber comprises adjacent subchambers each having a closure lid and said supply duct is located in a said lid and said deflector means is located in the corresponding said subchamber.

4. The apparatus of claim 2 wherein said supply duct between its entrance and exit portions is curved smoothly and gradually with said exit extending across the width of said chamber for distribution of said fluid cryogen across said width.

5. The apparatus of claim 4 wherein said supply duct is divided into laterally spaced sections by spaced vanes to provide side-by-side passages having adjacent entrances comprising said entrance portion that is adjacent said deflector means and exits comprising said exit porTion spanning substantially the entire width of said chamber.

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