Systems and methods for controlling warewasher wash cycle duration, detecting water levels and priming warewasher chemical feed lines

• US 6,918,398 B2
• Filed: 07/13/2004
• Issued: 07/19/2005
• Est. Priority Date: 11/04/2002
• Status: Active Grant

• Current Assignee: Premark FEG LLC (Illinois Tool Works Inc.)
• Original Assignee: Premark FEG LLC (Illinois Tool Works Inc.)
• Inventors: Edelmann, David Charles, Cartwright, Richard W., Hoying, Gary V.
• Primary Examiner(s): Stinson, Frankie L.
• Assistant Examiner(s): Perrin, Joseph L.
• Application Number:
  US10/889,687
• Publication Number:
  US 20040244819A1
• Time in Patent Office: 371 Days
• Field of Search: 134/25.2, 134/56.D, 134/57.D, 134/58.D, 134/95.1, 134/98.1, 134/107, 134/113, 134/186, 134/200
• US Class Current: 134/57.00D
• CPC Class Codes: A47L 15/0021 Regulation of operational steps within the washing processes, e.g. optimisation or improvement of operational steps depending from the detergent nature or from the condition of the crockery
• CPC Class Codes: A47L 15/0023 Water filling A47L15/4244 takes precedence
• CPC Class Codes: A47L 15/0055 Metering or indication of used products, e.g. type or quantity of detergent, rinse aid or salt; for measuring or controlling the product concentration
• CPC Class Codes: A47L 15/4244 Water-level measuring or regulating arrangements
• CPC Class Codes: A47L 15/4418 in the form of liquids A47L15/4409, A47L15/4436, A47L15/4445 take precedence
• CPC Class Codes: A47L 2401/023 Quantity or concentration of the consumable product
• CPC Class Codes: A47L 2401/09 Water level
• CPC Class Codes: A47L 2401/12 Water temperature
• CPC Class Codes: A47L 2401/30 Variation of electrical, magnetical or optical quantities
• CPC Class Codes: A47L 2501/01 Water supply, e.g. opening or closure of the water inlet valve
• CPC Class Codes: A47L 2501/26 Indication or alarm to the controlling device or to the user
• CPC Class Codes: A47L 2501/30 Regulation of machine operational steps within the washing process, e.g. performing an additional rinsing phase, shortening or stopping of the drying phase, washing at decreased noise operation conditions
• CPC Class Codes: A47L 2501/32 Stopping or disabling machine operation, including disconnecting the machine from a network, e.g. from an electrical power supply
• CPC Class Codes: Y10T 137/7287 Liquid level responsive or maintaining systems

Abstract

A system and method of selectively extending a wash cycle duration of a warewasher beyond a set minimum duration provides suitable cleaning of wares while at the same time seeking to increase the number of wash cycles per unit time. A system and method for detecting water level in a wash chamber or other tank provides the ability to identify a progressively fouling electrode. A system and method of automatically priming one or more chemical feed lines of a warewasher is also described.

Claims

1. A warewasher system, comprising:

a wash area for receiving objects to be washed;

means for delivering wash liquid to wares in the wash area during a wash cycle;

a tank and associated heater for heating rinse water;

a path for delivering water from the tank to the wash area;

a flow control device for controlling water flow along the path;

a temperature sensor for indicating a temperature of rinse water in the tank; and

a controller connected to receive input from the temperature sensor, connected to control the flow control device and the means for delivering wash liquid, and having at least one operating mode that, if active, will carry out the following steps for the wash cycle;

heat rinse water during the wash cycle; and

after the wash cycle runs for a set minimum duration;

end the wash cycle if the temperature of the rinse water has reached a desired rinse water temperature;

continue the wash cycle if the temperature of the rinse water has not reached the desired rinse water temperature and subsequently to;

(i) end the wash cycle if the temperature of the rinse water reaches the desired rinse water temperature;

(ii) end the wash cycle after a set maximum duration for the wash cycle even if the temperature of the rinse water has not reached the desired rinse water temperature.

2. A warewasher system, comprising:

a wash chamber for receiving objects to be washed;

a pump for recirculating wash water through the wash chamber during a wash cycle;

a tank and associated heater for heating rinse water;

a path for delivering water from the tank to the wash chamber;

a flow control device for controlling water flow along the path;

a temperature sensor for indicating a temperature of the rinse water in the tank; and

a controller connected to receive input from the temperature sensor, connected to control the flow control device and the pump and having at least one operating mode that, if active, will carry out the following steps for a wash cycle;

heat rinse water during the wash cycle; and

after the wash cycle runs for a set minimum duration;

end the wash cycle if the temperature of the rinse water has reached a desired rinse water temperature;

continue the wash cycle if the temperature of the rinse water has not reached the desired rinse water temperature and subsequently to;

(i) end the wash cycle if the temperature of the rinse water reaches the desired rinse water temperature;

(ii) end the wash cycle after a set maximum duration for the wash cycle even if the temperature of the rinse water has not reached the desired rinse water temperature.

3. The system of claim 2 wherein the set minimum duration, set maximum duration and desired rinse water temperature are stored in memory of the controller.

4. The system of claim 2 wherein the flow control device comprises a valve associated with an inlet of the tank and the path comprises an overflow path from the tank.