# US 4,397,814 A · Apparatus for providing overriding pressure in heat processing sealed containers

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- Number: US 4,397,814 A
- Document ID: US4397814A
- Status: Granted
- Kind: A
- Application number: 06/371,855
- Filed: 1982-04-26
- Granted: 1983-08-09
- Earliest claimed: 1980-06-19
- Assignees: FMC Corporation
- Inventors: Andrea Darecchio
- Web page: https://patentgrep.com/patent/US4397814A

## CPC

- A61L 2/24: Apparatus using programmed or automatic operation
- A23B 2/001: {Details of apparatus, e.g. pressure feed valves or for transport, or loading or unloading manipulation}
- A23B 2/003: {Control or safety devices for sterilisation or pasteurisation systems}
- A23B 2/20: by heating materials in packages which are progressively transported, continuously or stepwise, through the apparatus
- A23B 2/205: {with packages on a drum with horizontal axis (with packages moving on the spot while being transported A23B2/203)}
- A23B 2/30: by heating materials in packages which are not progressively transported through the apparatus
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- A23B: PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES

## Abstract

A conventional cooker or retort for heat processing sealed containers, such as sealed pouches, jars or cans, has an evaporator associated therewith. A source of water is coupled to the evaporator through a valve and a source of a liquid having a higher vapor pressure than water, such as ethyl alcohol, is connected to the evaporator through a metering pump. Pressure and temperature within the retort are monitored and signals indicative thereof are connected to controllers for metering the heat supplied to the evaporator and for metering the ethyl alcohol and water delivered to the evaporator. One controller is configured to operate so that as pressure rises, proportions of ethyl alcohol introduced into the evaporator is reduced while the proportion of water introduced is increased. Another controller functions to restrict the amount of heating medium, such as steam, delivered to the evaporator as the retort temperature increases. In this fashion a predetermined pressure and temperature is maintained within the retort such that an overriding pressure is provided relative to the pressure within the sealed containers being processed.

## Claims

### Claim 1

A system for heat processing sealed containers having a head-space and first liquid therein which vaporizes during processing, the containers being of the type capable of maintaining an internal pressure that is different than the pressure acting on the exterior of the containers, comprising;
a sealed heat treatment chamber adapted to receive a plurality of containers,
an evaporator for heating and vaporizing a processing liquid for providing the vapors to the sealed chamber at the processing temperature,
control means including a pressure sensor communicating with the heat treatment chamber for providing a pressure indicative output,
means for storing a quantity of a second liquid having a higher vapor pressure than the first liquid, and
means responsive to said pressure indicative output for controlling the flow of said second liquid between said means for storing and the evaporator for changing the proportion of the second liquid in the processing liquid so that a higher overriding pressure is provided in the treatment chamber than the pressure generated within the sealed containers.

### Claim 2 (depends on 1)

A system as in claim 1 wherein the processing liquid includes water, and further comprising conduit means for providing makeup water to said evaporator, means for controlling the flow of makeup water to the evaporator, said last named means being responsive to said pressure indicative output so that the proportion of water mixed into said processing liquid is increased when higher overriding pressures are sensed, said processing liquid being a mixture of mono-alcohol and water containing from 5-20% alcohol by weight.

### Claim 3

A system for heat processing sealed containers having a head-space and a first liquid therein which vaporizes during processing, the containers being of the type capable of maintaining an internal pressure that is different than the pressure acting on the exterior of the containers, comprising:
a sealed heat treatment chamber adapted to receive a plurality of containers,
an evaporator for vaporizing a processing liquid and for providing the vapors to the sealed chamber at the processing temperature,
control means including a temperature sensor communicating with the heat treatment chamber for providing a temperature indicative output,
control means including a pressure sensor communicating with a heat treatment chamber for providing a pressure indicative output,
means for storing a quantity of a second liquid having a vapor pressure higher than the first liquid,
means responsive to said pressure indicative output for controlling the flow of said second liquid between said means for storing and the evaporator, and
means responsive to said temperature indicative output for controlling heat applied to said processing liquid at the evaporator for maintaining the processing temperature constant and for providing a pressure that is greater within the heat treatment chamber than the pressure within the sealed containers.

### Claim 4 (depends on 3)

A system as in claim 3 wherein the processing liquid includes water, further comprising conduit means for providing makeup water to said evaporator, means for controlling the flow of makeup water to the evaporator, said last named means being directly responsive to said pressure indicative output for limiting the overriding pressure, said processing liquid comprising a mixture of mono-alcohol and water containing 5-20% alcohol by weight.

### Claim 5

A system for heat processing sealed containers having a head-space and a first liquid therein which vaporizes during processing, the containers being of the type capable of maintaining an internal pressure that is different than the pressure acting on the exterior of the containers, comprising;
a sealed heat treatment chamber adapted to receive a plurality of the containers,
an evaporator for vaporizing a processing liquid and for providing the vapors to the sealed chamber at the processing temperature,
control means including a temperature sensor communicating with the heat treatment chamber for providing a temperature indicative output,
means for storing a quantity of a second liquid having a higher vapor pressure than the first liquid, and
means responsive to said temperature indicative output for controlling the flow of said second liquid between said means for storing and the evaporator so that an overriding pressure is provided in the treatment chamber that is higher than the pressure generated within the sealed containers.

### Claim 6 (depends on 5)

A system as in claim 5 wherein the processing liquid includes water, further comprising conduit means connecting said evaporator to a makeup water supply, means for controlling the flow of makeup water to the evaporator, said last named means being responsive to said temperature indicative output so that the proportion of water mixed into said second liquid is decreased when higher temperatures are sensed, said processing liquid being a mixture of mono-alcohol and water containing from 5-20% alcohol by weight.