Automatic system and method for removing mineral deposits from a dishwasher

• US 6,551,414 B2
• Filed: 01/19/2001
• Issued: 04/22/2003
• Est. Priority Date: 01/19/2001
• Status: Expired due to Term

• Current Assignee: Diversey Incorporated (Sealed Air)
• Original Assignee: Us Chemical Corporation (Sealed Air)
• Inventors: Reichold, Kurt A.
• Primary Examiner(s): Gulakowski, Randy
• Assistant Examiner(s): Winter, Gentle E
• Application Number:
  US09/766,441
• Publication Number:
  US 20020096192A1
• Time in Patent Office: 823 Days
• Field of Search: 134/2, 134/10, 134/22.19, 134/18, 134/104.1, 134/113, 134/570, 134/102.2, 427/98, 610/224, 165/303
• US Class Current: 134/18
• 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 15/0081 with vertical sliding closing doors, e.g. hood-type dishwashers
• CPC Class Codes: A47L 15/4236 Arrangements to sterilize or disinfect dishes or washing liquids A47L15/4234 takes precedence
• CPC Class Codes: A47L 15/46 Devices for the automatic control of the different phases of cleaning ; Controlling devices A47L15/449 takes precedence
• CPC Class Codes: A47L 2401/20 Time, e.g. elapsed operating time
• CPC Class Codes: A47L 2401/22 Number of operational cycles
• CPC Class Codes: A47L 2501/01 Water supply, e.g. opening or closure of the water inlet valve
• CPC Class Codes: A47L 2501/02 Water discharge, e.g. opening or closure of discharge valve
• CPC Class Codes: A47L 2501/05 Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
• CPC Class Codes: A47L 2501/07 Consumable products, e.g. detergent, rinse aids or salt

Abstract

Whenever a dishwasher is operated a given number of times or whenever a given number of days transpire, an apparatus performs a process that removes minerals deposits that have built-up inside the dishwasher. The process commences by rinsing the dishwasher interior with water and draining the rinse water. A mixture of water and a chemical that dissolves the minerals is introduced into the dishwasher and a pump circulates the mixture inside the dishwasher for a period of time. Next the mixture is drained out and the dishwasher interior is rinsed again with fresh water.

Claims

1. An apparatus for automatically removing mineral deposits from an interior of a dishwasher, wherein the dishwasher has a water valve, a drain valve, and a wash pump, said apparatus comprising:

a mechanism which determines when to commence a descaling operation, wherein the mechanism comprises either a clock apparatus which produces a descaling indication upon a given amount of time elapsing since a previous removal mineral deposits from the dishwasher or a counter which produces the descaling indication upon the occurrence of a predefined number of operating cycles of the dishwasher;

a reservoir for containing a chemical which cleanses mineral deposits from surfaces of objects;

a flow control device which couples the reservoir to the dishwasher and controls a flow of the chemical into the dishwasher; and

a controller connected to the water valve, the drain valve, the wash pump and the control device, wherein the controller responds to the descaling indication by operating the water valve and the control device to introduce water and the chemical into the dishwasher, activates the wash pump to circulate a mixture of water and the chemical inside the dishwasher, and thereafter opens thc drain valve to remove the mixture from the dishwasher.

2. The apparatus as recited in claim 1 wherein the control device is a pump.

3. The apparatus as recited in claim 1 wherein the control device is a valve.

4. The apparatus as recited in claim 1 wherein after the controller opens the drain valve to remove the mixture from the dishwasher, the controller operates the water valve, the drain valve and the wash pump to rinse the interior of the dishwasher.

5. The apparatus as recited in claim 1 wherein in response to the descaling indication, the controller operates the water valve, the drain valve and the wash pump to rinse the interior of the dishwasher, before the controller operates the water valve and the control device to introduce water and the chemical into the dishwasher.

6. The apparatus as recited in claim 1 further comprising a chemical within the reservoir which cleanses mineral deposits from surfaces of objects.

7. An apparatus for automatically removing mineral deposits from an interior of a dishwasher, wherein the dishwasher has a water valve, a drain valve, and a wash pump, said apparatus comprising:

a mechanism which determines when to remove mineral deposits, wherein the mechanism comprises either a clock apparatus which produces a descaling indication upon a given amount of time elapsing since a previous removal mineral deposits from the dishwasher or a counter which produces the descaling indication upon the occurrence of a predefined number of operating cycles of the dishwasher;

a reservoir for containing a chemical which cleanses mineral deposits from surfaces of objects;

a flow control device which couples the reservoir to the dishwasher and controls a flow of the chemical into the dishwasher in response to an electrical signal;

an electrical controller connected to the water valve, the drain valve, the wash pump and the control device, wherein the controller responds to the descaling indication by operating a descaling procedure by (1) operating the water valve, the drain valve and the wash pump to rinse the interior of the dishwasher, (2) then operating the water valve and the control device to introduce water and the chemical into the dishwasher, activating the wash pump to spray a mixture of water and the chemical inside the dishwasher, followed by opening the drain valve to remove the mixture from the dishwasher, and (3) thereafter operating the water valve, the drain valve and the wash pump to rinse the interior of the dishwasher.

8. The apparatus recited in claim 7 wherein the control device is a pump.

9. The apparatus recited in claim 7 wherein the control device is a valve.

10. A dishwasher comprising;

a cabinet defining a chamber into which dishes are loaded for washing;

a washing and rinsing apparatus in the chamber;

a water valve which controls a flow of water from a supply into the chamber;

a drain valve which controls a flow of water from the chamber to a drain line;

a wash pump for circulating water through the washing and rinsing apparatus;

a mechanism which determines when to remove mineral deposits from the chamber, wherein the mechanism comprises either a clock apparatus which produces a descaling indication upon a given amount of time elapsing since a previous removal mineral deposits from the chamber or a counter which produces the descaling indication upon the occurrence of a predefined number of operating cycles of the chamber;

a reservoir for containing a chemical which cleanses mineral deposits from surfaces of objects;

a flow control device which couples the reservoir to the chamber and controls a flow of the chemical there between; and

a controller connected to the water valve, the drain valve, the wash pump and the control device, wherein the controller responds to the descaling indication by operating the water valve and the control device to introduce water and the chemical into the chamber, activates the wash pump to circulate a mixture of water and the chemical inside the chamber, and thereafter opens the drain valve to remove the mixture from the dishwasher.

11. A method for automatically removing mineral deposits from an interior of a dishwasher, said method comprising:

providing a reservoir that contains a chemical which cleanses mineral deposits from surfaces of objects;

connecting the reservoir by a flow control device to the dishwasher, wherein the flow control device selectively regulates flow of the chemical into the dishwasher;

determining an occurrence of a predefined event which indicates that time has come to remove mineral deposits from the dishwasher; and

in response to that occurrence;

(a) operating the water valve and the control device to introduce water and the chemical into the dishwasher;

(b) activating the wash pump to spray a mixture of water and the chemical inside the dishwasher; and

(c) operating the drain valve to remove the mixture from the dishwasher.

12. The method as recited in claim 11 wherein determining an occurrence of a predefined event comprises measuring usage of the dishwasher;

and determining that the predefined event has occurred when the usage reaches a predefined level.

13. The method as recited in claim 11 wherein determining an occurrence of a predefined event comprises counting when the dishwasher is operated, thereby producing a count;

and determining that the predefined event has occurred when the count reaches a predefined value.

14. The method as recited in claim 11 wherein determining an occurrence of a predefined event comprises determining that a predefined amount of time has elapsed since a previous removal of mineral deposits from the dishwasher.

15. The method as recited in claim 11 further comprising, prior to operating the water valve and the control device to introduce water and the chemical into the dishwasher, operating the water valve and the wash pump to rinse the interior of the dishwasher.

16. The method as recited in claim 15 further comprising, after the interior of the dishwasher has been rinsed, operating the drain valve to remove rinse water from the dishwasher.

17. The method as recited in claim 11 further comprising, after, operating the drain valve to remove the mixture from the dishwasher, operating the water valve and the wash pump to rinse the interior of the dishwasher.

18. The method as recited in claim 17 further comprising, after the interior of the dishwasher has been rinsed, operating the drain valve to remove rinse water from the dishwasher.