Low temperature washing and chemical sanitizing of foodware

Method for operating a batch-type machine providing washing of soiled foodwares and chemical sanitizing rinsing of washed foodwares to maximize production rate while minimizing energy demand rate at an installation site, comprising

• providing a foodware cleansing machine having a single wash and rinse chamber with a wash water sump which, after an initial filling with wash water, is maintained at a desired wash water level and a desired wash water temperature by drainage of water into such wash water sump after wash and rinse spraying of foodware items,
• such foodware cleansing machine including a separate fresh water accumulation tank capable of holding a predetermined volume of fresh water between at least about one-third and about one-half the capacity of the wash sump and preheated above desired wash water temperature,
• inserting a load of foodware items into the foodware cleansing machine,
• establishing a preselected wash phase time,
• establishing a preselected rinse phase time,
• washing the load of soiled foodware items by pumping wash water from the wash sump to provide pressurized discharge of such wash water on such foodware items,
• controlling pumping of such wash water such that such pressurized wash spraying extends over such preselected wash phase time,
• terminating pumping of wash water from such wash sump at expiration of such predetermined wash phase time,
• providing a dwell time after terminating such wash spraying for drip drainage of wash water into the wash sump,
• controlling supply of preheated fresh water from the installation site to such fresh water accumulation tank including control of flow rate of such fresh water,
• such control causing flow of fresh water into such accumulation tank to start substantially simultaneously with initiation of pumping of wash water from the wash sump and to extend predeterminedly during such wash phase time,
• sensing the volume of fresh water accumulated in the fresh water accumulation tank at least when such accumulating fresh water reaches the preselected volume between one-third and about one-half of wash sump capacity,
• such control of fresh water flow rate causing flow of fresh water into such accumulation tank means to extend over substantially the entire preselected wash phase time while providing for terminating flow of fresh water into such accumulation tank when such preselected volume of fresh water in the fresh water accumulation tank is sensed prior to expiration of the preselected wash phase time,
• terminating flow of fresh water to such accumulation tank at expiration of such predetermined wash phase time unless earlier terminated responsive to sensing accumulation of such preselected volume of fresh water,
• pumping such accumulated fresh water at a predetermined pressure to provide uniform flow of such accumulated fresh water within a rinse line to provide pressurized discharge for rinse spraying onto such washed load,
• controlling pumping of such accumulated fresh water to extend over such preselected rinse phase time,
• pressurizing a liquid chemical sanitizing agent,
• injecting such liquid chemical sanitizing agent under pressure into such flow of fresh water in the rinse line,
• such injecting of liquid chemical sanitizing agent into such rinse line taking place shortly prior to the pressurized rinse spraying on such washed load,
• such liquid chemical sanitizing agent being injected into such rinse line to have a component of movement in the direction of fresh water flow,
• controlling such pressurized injection of liquid chemical sanitizing agent to take place uniformly over at least a preselected major portion of the preselected rinse phase time,
• such rinse phase time being preselected to be between about one-tenth and about one-half the wash phase time,
• terminating pressurized injection of liquid chemical sanitizing agent, and with expiration of such preselected rinse phase time,
• terminating pressurized pumping of fresh water in the rinse to complete a cycle prior to unloading of such washed and rinsed foodware item load.

Batch-type foodware cleansing apparatus for washing of soiled foodware items followed by chemical sanitizing rinsing of washed foodware items comprising

• enclosure means for receiving a load of foodware items including a single chamber for washing and rinsing of such items,
• wash sump means of predetermined capacity for holding wash water and receiving wash water and rinse water after spraying over foodware items in the chamber,
• wash spray means in the chamber,
• wash pump means for pressurized pumping of water from the wash sump means to wash spray means in the chamber,
• a separate fresh water accumulation tank means capable of holding a volume of preheated fresh water between about one-third and about one-half the capacity of the wash sump,
• fresh water supply line means connected to the fresh water accumulation tank means,
• flow control means in such fresh water supply line means for controlling fresh water flow into such fresh water accumulation tank means, such flow control means including flow rate control means,
• rinse spray means located in the chamber means,
• a rinse line extending from the fresh water accumulation tank means to the rinse spray means,
• rinse pump means for pressurized pumping of water from the fresh water accumulation tank means to the rinse spray means,
• means for supplying liquid chemical sanitizing agent,
• means for introducing liquid chemical sanitizing agent into the rinse line at a location contiguous to entry into the chamber, and
• means controlling cycling of such foodware cleansing apparatus including controlling actuation of such pump means for respective wash phase and rinse phase times such that the rinse phase time follows completion of the wash phase time and the fresh water flow to the fresh water accumulation tank means extends over at least a major portion of the wash phase time.