US3733848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Freezing system
Assignee: Airco Inc
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Filing: 1971-08-09
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Granted: 1973-05-22
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Expires: 1991-08-09
Abstract
Abstract A high rate freezing system comprising an insulating housing wherein expansion of liquid carbon dioxide (CO2) maintains a freezing atmosphere. A belt conveyor with multiple flights defining a vertical helix passes food products through the housing. A plurality of line-flow blowers with vertical axes of rotation at spaced positions around the helix direct wide streams of cold CO2 gas respectively, generally tangentially across all the conveyor flights for causing swirling movement of the gas throughout the helix.
Inventors
- 👤 P Duron
- 👤 T Carter
- 👤 F Mondok
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:39
CPC Classifications
F; F25; F25D; F25D25/00; F25D25/04; F25D3/00; F25D3/10; F25D3/11; B; B65; B65G; B65G2207/00; B65G2207/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
155 words
A high-rate food freezing unit comprising: a. an insulating housing having an inlet port and an outlet port for passage through the unit of food to be frozen; b. a food conveyor having flights extending transversely of the housing and defining a continuous vertical helix centrally of the housing between upper and lower housing levels for carrying the food from the inlet to the outlet port; c. means for introducing low temperature gas into the housing to form a cold atmosphere for refrigerating the unit; and d. line-flow blower means having a substantially horizontal plane of rotation for circulating the cold atmosphere through the conveyor, the line-flow discharge of the blower means being in a direction generally tangential to said helix and across adjacent of said flights and said blower being of such length that said discharge spans at least a substantial number of the conveyor flights for directing the cold atmosphere across said flights.
Claim 2
Dependent Claim
155 words
A high-rate food freezing unit comprising: a. an insulating housing having an inlet port and an outlet port for passage through the unit of food to be frozen; b. a food conveyor having flights extending transversely of the housing and defining a continuous vertical helix centrally of the housing between upper and lower housing levels for carrying the food from the inlet to the outlet port; c. means for introducing low temperature gas into the housing to form a cold atmosphere for refrigerating the unit; and d. line-flow blower means having a substantially horizontal plane of rotation for circulating the cold atmosphere through the conveyor, the line-flow discharge of the blower means being in a direction generally tangential to said helix and across adjacent of said flights and said blower being of such length that said discharge spans at least a substantial number of the conveyor flights for directing the cold atmosphere across said flights.
Claim 3
Dependent Claim
49 words
2, A freezing unit as specified in claim 1 wherein the blower means includes at least two similar blower units located respectively at spaced positions alongside the conveyor, each blower having a vertical axis of rotation for directing a line-flow stream between and across the flights of the conveyor.
Claim 4
Dependent Claim
28 words
A freezing unit as specified in claim 2 wherein the introducing means comprises C02 injecting means to direct C02 vapor into the discharge path of the blower means.
Claim 5
Dependent Claim
49 words
A freezing unit as specified in claim 3 wherein the conveyor constitutes an endless belt defining said vertical helix centrally of the housing, and the blower means direct respective line-flow streams through the peripheral part of the helix for creating swirling movement of the C02 atmosphere within the helix.
Claim 6
Dependent Claim
60 words
A freezing unit as specified in claim 4 wherein a third line-flow blower unit is similarly positioned alongside the periphery of the helix and spaced from the other two units and the line-flow stream from each of the units is directed in generally tangential relation to the helix for cumulative effect in creating the swirling movement of the C02 atmosphere.
Claim 7
Dependent Claim
55 words
A freezing unit as specified in claiM 4 wherein the housing inlet port is opposite the lowest flight of the conveyor, and the conveyor moves the food therefrom in gradual ascent and in opposition to corresponding line-flow streams within a continuously swirling C02 atmosphere, to the outlet port opposite the upper flight of the conveyor.
Claim 8
Dependent Claim
38 words
A freezing unit as specified in claim 1 wherein a main exhaust duct extends across the housing and has branches extending respectively downward to the inlet and outlet ports for restricting entry of ambient air into the housing.
Claim 9
Dependent Claim
43 words
A freezing unit as specified in claim 3 wherein the C02 injecting means constitutes at least two expansion nozzles that are each located respectively generally above the discharge paths of the individual blower units for directing C02 vapor into the corresponding discharge path.
Claim 10
Dependent Claim
72 words
A freezing unit as specified in claim 4 wherein the blower units and conveyor are mounted centrally of the housing within an open supporting frame, the blower units being positioned in respective corners of the frame and oriented for cumulative swirling effect of the respective discharge streams about the helix and the corresponding blower driving motor is exteriorly mounted in vertical alignment on the top wall of the housing for ready servicing.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |