Method for air transport of sanitizing liquid to a warewasher

• US 4,209,343 A
• Filed: 09/01/1978
• Issued: 06/24/1980
• Est. Priority Date: 04/15/1977
• Status: Expired due to Term

• Current Assignee: Premark FEG LLC (Illinois Tool Works Inc.)
• Original Assignee: Hobart Corporation (Illinois Tool Works Inc.)
• Inventors: Fraula, Louis F., Lane, Buddy F.
• Primary Examiner(s): Bashore, S. Leon
• Assistant Examiner(s): Goldman, Michael
• Application Number:
  US05/938,931
• Time in Patent Office: 662 Days
• Field of Search: 134/37, 134/36, 134/102, 134/100, 134/101, 134/94, 134/95, 134/22 R, 134/25 A, 134/29, 134/30, 134/22 C, 222/193, 222/630, 417/151, 68/17 R, 239/8, 239/9, 239/308, 239/337, 239/369
• US Class Current: 134/22.12
• CPC Class Codes: A47L 15/0057 Cleaning of machines parts, e.g. removal of deposits like lime scale or proteins from piping or tub
• CPC Class Codes: A47L 15/4236 Arrangements to sterilize or disinfect dishes or washing liquids A47L15/4234 takes precedence
• CPC Class Codes: A47L 15/4427 entrained in the water supply line by a pressure drop, e.g. resulting from a Venturi throat
• CPC Class Codes: B01F 2101/4505 Mixing ingredients comprising detergents, soaps, for washing, e.g. washing machines
• CPC Class Codes: B01F 25/312 with Venturi elements; Details thereof

Abstract

A rapidly moving air stream transports an air unstable sanitizing agent such as sodium hypochlorite from a liquid supply thereof directly to a tank containing water, such as the wash chamber of a dishwasher. The air is driven through a venturi powered aspirator which injects the sanitizing agent into the air stream and transports it to the warewasher for mixture with the water to provide an effective bactericide. Contact of the aspirated agent with air is preferably kept to a minimum by transporting it through a short hose interconnecting the aspirator and tank.

Claims

1. For use in a washing machine having a tank containing a predetermined quantity of water for spraying onto food-associated articles within the machine to clean and sanitize them, a method for dispensing a predetermined quantity of an air unstable chemical sanitizing liquid, such as a saline solution of sodium hypochlorite, by means of air transport of the liquid into the water, comprising the steps of:

(a) actuating a source of compressed air for a predetermined time period,

(b) using the compressed air to aspirate the sanitizing liquid from a supply thereof, and

(c) transporting the sanitizing liquid to the tank, by means of the compressed air, with minimum effective exposure of the sanitizing liquid to air prior to mixing with the water within the tank.

2. The method of claim 1 wherein the liquid is transported from the supply thereof through a pipe, and wherein said transporting step further comprises cleansing the pipe of precipitates previously deposited from sanitizing liquid which remained in the pipe following a previous actuation of the source of compressed air.

3. The method of claim 1 wherein the aspirated liquid enters the tank as a substantially unatomized coarse stream.

4. The method of claim 1 wherein the water is fresh water for simultaneously rinsing and sanitizing the washed articles as the final step in the cleaning thereof.

5. For use in a washing machine having a tank containing a predetermined quantity of fresh water for spraying onto food-associated articles within the machine to clean and sanitize them, a method for dispensing a predetermined quantity of an air unstable chemical sanitizing liquid, such as a saline solution of sodium hypochlorite, by means of air transport of the liquid into the water, for simultaneously rinsing and sanitizing the washed articles as the final step in the cleaning thereof, comprising the steps of:

(a) actuating a source of compressed air for a predetermined time period,

(b) using the compressed air to aspirate the sanitizing liquid from a supply thereof,

(c) transporting the sanitizing liquid through a pipe to the tank, by means of the compressed air, with minimum effective exposure of the sanitizing liquid to air prior to mixing with the water within the tank, and with simultaneous cleansing of the pipe of precipitates previously deposited from sanitizing liquid which remained in the pipe following a previous actuation of the source of compressed air, and

(d) introducing the liquid into the tank as a substantially unatomized coarse stream.

6. The method of dispensing a predetermined quantity of an air unstable chemical sanitizing liquid, such as an aqueous solution of sodium hypochlorite, into a predetermined quantity of rinse water for mixing with the water and for dispersing by spraying onto washed articles used in conjunction with food, to disinfect the articles, comprising the steps of:

(a) supplying the predetermined quantity of rinse water in a tank,

(b) directing air under a predetermined pressure along a confined path terminating at said tank,

(c) creating a reduced pressure below atmospheric at a portion along said confined path as a result of air flow past said portion,

(d) conducting said aqueous solution from a supply thereof at ambient pressure to said reduced pressure portion by evacuation through a conduit and then transporting the solution from said portion to said tank by air flow through said path, and,

(e) maintaining the pressurized air in the confined path for a predetermined time period calculated to withdraw the predetermined quantity of aqueous solution from the supply and convey it to the tank.

7. The method of claim 6 wherein the solution is evacuated through said conduit in a continuous liquid stream, and further comprising the step of reducing said continuous stream to discrete droplets upon reaching said reduced pressure portion.