Patent US4317665A successfully refreshed from Google Patents.
US4317665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryogenic freezing system
Assignee: Air Products and Chemicals Inc
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Filing: 1980-12-22
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Granted: 1982-03-02
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Expires: 2000-12-22
Abstract
Abstract The operation of a prior art freezer installation for freezing food can be improved by: (1) providing air curtains at the doors of the freezer; (2) using a pulse bag filter for separating ice from the air leaving the freezer; and (3) ensuring that the air leaving the freezer is colder than -80° F.
Inventors
- 👤 Alan L. Prentice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:06
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/02; B01D46/04; A; A23; A23B; A23B2/00; A23B2/80; A23B2/85; A23B2/88; B01D46/42; B01D46/4281; B01D46/66; B01D46/70; B01D46/71; F; F25; F25B; F25B9/00; F25B9/002; F25B9/004; F25D; F25D21/00; F25D21/06; B01D2201/00; B01D2201/31; B01D2201/313
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
212 words
In an apparatus for freezing articles comprising in combination a freezer having an inlet for admitting the articles to be frozen, an outlet for permitting the frozen articles to leave said freezer and a conveyor for transporting the articles through said freezer from said inlet to said outlet thereof; a refrigerant supply main connected to said freezer for introducing refrigerant air to said freezer; a return main connected to said freezer for receiving the warmed air from said freezer; refrigeration means connected to said refrigerant supply main for supplying said supply main with air a cryogenic temperatures; and a main heat exchanger having a high pressure side connected to said refrigeration means and a low pressure side connected between said refrigeration means and said return main for exchanging the refrigerant value of said warmed air from said return main in said low pressure side with the air from said refrigeration means in said high pressure side; the improvement which comprises; bag filter means connected between said return main and said main exchanger for removing ice particles from the warmed air in said return main prior to exchanging its refrigeration value in said main heat exchanger, which filter means comprises at least one bag which is periodically pulsed to remove ice collected therein.
Claim 2
Dependent Claim
212 words
In an apparatus for freezing articles comprising in combination a freezer having an inlet for admitting the articles to be frozen, an outlet for permitting the frozen articles to leave said freezer and a conveyor for transporting the articles through said freezer from said inlet to said outlet thereof; a refrigerant supply main connected to said freezer for introducing refrigerant air to said freezer; a return main connected to said freezer for receiving the warmed air from said freezer; refrigeration means connected to said refrigerant supply main for supplying said supply main with air a cryogenic temperatures; and a main heat exchanger having a high pressure side connected to said refrigeration means and a low pressure side connected between said refrigeration means and said return main for exchanging the refrigerant value of said warmed air from said return main in said low pressure side with the air from said refrigeration means in said high pressure side; the improvement which comprises; bag filter means connected between said return main and said main exchanger for removing ice particles from the warmed air in said return main prior to exchanging its refrigeration value in said main heat exchanger, which filter means comprises at least one bag which is periodically pulsed to remove ice collected therein.
Claim 3
Dependent Claim
45 words
The apparatus of claim 1 wherein the ice particles are removed in said bag filter means through the pulsing action of a portion of the air leaving the high pressure side of said main heat exchanger and have a diameter of 1 micron or greater.
Claim 4
Dependent Claim
28 words
The apparatus of claim 1 wherein air is introduced into said freezer at or colder than -180° F. and is withdrawn from said freezer colder than -80° F.
Claim 5
Dependent Claim
29 words
The apparatus of claim 1 wherein means are provided for supplying a curtain of dry air over said inlet and said outlet to control heat loss from said freezer.
Claim 6
Dependent Claim
154 words
In a method for cryogenically freezing articles comprising the steps of: (a) contacting articles in a freezer with air at a temperature of about -180° F. or colder; (b) continuously withdrawing a portion of the warmed air from the freezer after contacting the articles within the freezer with the air; (c) alternately compressing the warmed air from step (b) and cooling the compressed air stream to a temperature substantially above - -180° F.; (d) exchanging the refrigeration valve of the air from step (b) with at least a portion of the compressed air stream from step (c); and (e) expanding the compressed air stream from step (d) to cool it to a temperature of about - -180° F. or colder for use in said freezer; the improvement which comprises passing the warmed air from step (b) through a bag of a bag filter and collecting the ice particles on the outside of the bag.
Claim 7
Dependent Claim
154 words
In a method for cryogenically freezing articles comprising the steps of: (a) contacting articles in a freezer with air at a temperature of about -180° F. or colder; (b) continuously withdrawing a portion of the warmed air from the freezer after contacting the articles within the freezer with the air; (c) alternately compressing the warmed air from step (b) and cooling the compressed air stream to a temperature substantially above - -180° F.; (d) exchanging the refrigeration valve of the air from step (b) with at least a portion of the compressed air stream from step (c); and (e) expanding the compressed air stream from step (d) to cool it to a temperature of about - -180° F. or colder for use in said freezer; the improvement which comprises passing the warmed air from step (b) through a bag of a bag filter and collecting the ice particles on the outside of the bag.
Claim 8
Dependent Claim
25 words
The method of claim 5 wherein the ice particles collected on the bag of said bag filter have a diameter of one micron or greater.
Claim 9
Dependent Claim
34 words
The method of claim 5 or 6 wherein a small portion of the compressed air stream from step (d) is periodically passed to said bag filter to dislodge the ice collected on the bag.
Claim 10
Dependent Claim
26 words
The method of claim 5 or 6 wherein at least 99.9% by weight of the ice particles are removed from the warm air leaving the freezer.
Claim 11
Dependent Claim
20 words
The method of claim 5 or 6 wherein step (c) comprises 3 stages of compression with intercooling between each stage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-03-01 | 1985-08-31 | 1986-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-01 | 1989-08-31 | 1990-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-01 | 1993-08-31 | 1994-03-02 | $7700.00 | Window Closed / Lapsed |