FIELD OF THE INVENTION

The present invention relates to the use of recycled wash and rinse water for pre-rinse operation in a dishwashing machine.

BACKGROUND OF THE INVENTION

A typical dishwashing process includes manually removing large food particles from soiled dishes using a spatula, tapping the dishes against the side or the edge of a waste container, or other suitable methods. In commercial applications, the operator typically then sprays the soiled dishes with fresh, warm to hot water using a pre-rinse spray hose. In a typical manual pre-rinse operation, the operator uses a commercially available pre-rinse spray hose to spray fresh water onto the soiled dishes, which does not contain any chemicals and is typically at a temperature of between 100 and 120° F. The dishes are then loaded into a dish rack of a dishwashing machine. Optionally, when using a door type, single rack, dishwashing machine, the operator will load the soiled dishes into the dish rack of the dishwashing machine and then use the pre-rinse hose to pre-rinse the dishes. The dish rack is then loaded into the cavity of the dishwashing machine for the automatic wash and rinse operations of the dishwashing machine.

Commercial door type dishwashing machines generally fall into the following four categories: high temperature sanitizing dishwashing machines, chemical sanitizing dishwashing machines, fresh water rinse dishwashing machines, and “dump and fill” dishwashing machines. Many combinations of these categories exist. Wash and rinse times, temperatures, and mechanical action are regulated by NSF standards. In all cases, a portion of the wash and/or rinse water is drained from the machine, either by directly opening a drain mechanism or by using an overflow conduit. The drained water is relatively clean as the water will typically pass through some filtering devices such as screens before reaching the sewer drain. Depending upon the type of dishwashing machine, the temperature of the drained water will typically be between 110 and 150° F., and the water will contain chemicals such as detergent, rinse aid, and sanitizing chemicals.

It is desired to reduce the amount of water and energy used to wash dishes, including the pre-rinse of dishes. Rather than using fresh, heated water in the pre-rinse operation of the dishes, the present invention uses the waste water of the dishwashing machine in the pre-rinse operation of the dishes to reduce the amount of water and energy used to wash dishes.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a dishwashing machine is used for pre-rinse operation of soiled dishes. A cavity is configured and arranged to contain the soiled dishes. A nozzle is proximate the cavity and is in fluid communication with the cavity. An accumulator pan accumulates wash and rinse water including cleaning chemicals used in a previous cycle of the dishwashing machine. A fluid passageway interconnects the nozzle and the accumulator pan. A pump directs the accumulated wash and rinse water from the accumulator pan to the nozzle via the fluid passageway for pre-rinse operation of the soiled dishes in the cavity, and the nozzle directs the accumulated wash and rinse water into the cavity with the soiled dishes to assist in removing soil from the soiled dishes prior to a wash cycle of the dishwashing machine. The wash cycle utilizes fresh wash water.

In another aspect of the present invention, a dishwashing machine is used for pre-rinse operation of soiled dishes for use with a dispenser for dispensing a use solution. A first cavity is configured and arranged to contain first dishes. A first nozzle is contained within the first cavity. A first pump is configured and arranged to direct use solution from the first cavity into the first nozzle in the first cavity, and the first nozzle is configured and arranged to direct the use solution onto the first dishes in the first cavity. A second cavity is in fluid communication with the first cavity and is configured and arranged to contain second dishes. A second nozzle is in fluid communication with the second cavity. A second pump is configured and arranged to direct use solution received from the first cavity into the second nozzle, and the second nozzle is configured and arranged to direct the use solution onto the second dishes in the second cavity.

In another aspect of the present invention, a dishwashing machine is used for pre-rinse operation of soiled dishes. A cavity is configured and arranged to contain the soiled dishes. A first nozzle and a second nozzle are proximate the cavity and are in fluid communication with the cavity. A sump is configured and arranged to contain wash water. An accumulator pan accumulates wash and rinse water including chemicals used in at least one previous wash cycle of the dishwashing machine. The sump is in fluid communication with the accumulator pan. A first fluid passageway interconnects the first nozzle and the accumulator pan. A first pump directs the accumulated wash and rinse water from the accumulator pan to the first nozzle via the first fluid passageway for pre-rinse operation of the soiled dishes in the cavity, and the first nozzle directs the accumulated wash and rinse water into the cavity with the soiled dishes to assist in removing soil from the soiled dishes prior to a wash cycle of the dishwashing machine. A second fluid passageway interconnects the second nozzle and the sump. A second pump directs the wash water from the sump to the second nozzle via the second fluid passageway. The wash cycle utilizes fresh wash water, and the wash water used in the wash cycle is emptied from the sump into the accumulator pan.

In another aspect of the present invention, a method of recycling wash and rinse water used in wash and rinse cycles of a dishwashing machine for use in pre-rinse operation of soiled dishes comprises running the wash and rinse cycles of the dishwashing machine, collecting the wash and rinse water from the wash and rinse cycles, placing the soiled dishes in a cavity, and directing the collected wash and rinse water into the cavity proximate the soiled dishes thereby providing pre-rinse operation of the soiled dishes with the collected wash and rinse water from previous wash and rinse cycles of the dishwashing machine. The cavity could be part of or separate from the dishwashing machine and could be selected from the group consisting of a portion of the dishwashing machine, a sink, or a portion of another dishwashing machine. The collected wash and rinse water could be drained after use in the pre-rinse operation of the soiled dishes.

