Continuous duty chemically sanitizing batch rinse system

#This invention relates to warewashing machines, and more particularly to a chemically sanitizing rinse system which is particularly adapted for use in continuous duty warewashing machines such as conveyorized warewashers.

#The inventions set forth in U.S. Pat. Nos. 4,142,539, 4,147,558, 4,147,559 and 4,209,343, all assigned to the assignee of the present invention represent major advances in energy saving chemically sanitizing warewasher technology. By air pumping and transporting the sanitizer (such as liquid sodium hypochlorite), by preparing the rinse solution in discrete batches, and by using the additional features taught therein, as appropriate, such as separately introducing the fresh rinse water and the concentrated sanitizer into a tank where dilution then takes place, the use of a rinse solution mixing tank which is separate from the wash and/or rinse chamber, the use of an independent rinse solution pump, and so forth, significant and important improvements in serviceability, reliability, and durability have been realized. Long felt needs extending over several decades have finally been met.

#A review of the above-noted patents, however, will show that they are all directed to what may be termed "stationary rack" warewashing machines. By "stationary rack" is meant a machine in which the rack of dishes or other foodware is inserted and then left in a single or stationary position while the machine subjects it to consecutive washing and rinsing operations at that location. Some machines can hold several racks at once, but the distinguishing feature is that the racks remain stationary and the several washing and rinsing operations are all performed without movement of the rack. At the end of the machine cycle the rack is removed.

#FIG. 1 is a front view of a conveyorized warewashing machine incorporating a continuous duty chemically sanitizing batch rinse system according to the present invention;

#FIG. 2 is a top view of the batch rinse system;

#FIGS. 3A and 3B are diagrammatic illustrations of the principal components of the conveyorized warewashing machine and the batch rinse system;

#FIG. 1 illustrates a conveyorized or conveyor-type warewashing machine 10 which incorporates a continuous duty chemically sanitizing batch rinse system according to the present invention. Referring to FIG. 3A, the warewashing machine 10 has a prewash station 12, a wash station 14, and a rinse station 16, and typically includes an endless chain conveyor or an indexing conveyor 18 for moving foodware items in racks R or otherwise, through the successive stations in the direction of the arrows in FIGS. 1 and 3A. Also, the machine 10 includes a rack or foodware detector 20 disposed adjacent the conveyor 18 and extending into the path of the racks R or ware at the entrance to the rinse station 16. Rinsing of a rack of foodware items at station 16 is initiated upon deflection of the detector 20 when contacted by the rack.

#One form of the batch rinse system of the present invention, being illustrated in FIGS. 2 and 3B, includes a rinse solution mixing tank 22 and a rinse pump 24 for supplying rinse solution 26 from the tank 22 through pipe 28 to upper and lower dedicated rinse arms 30 and 32 stationarily mounted in the rinse station 16 above and below the path of movement of the racks R. Thus, the rinse solution 26 in tank 22 is pumped, on demand, by the rinse pump 24 through the rinse pipe 28, and to the rinse station 16 whenever a rack R of foodware items is detected in station 16 by the detector 20. Rinse station 16, as well as stations 12 and 14, may be any conventional and well-known designs of the kinds used in conveyorized warewashing machines for many years. Likewise, the detector 20 in the rinse station may be a conventional and well-known kind, such as a switch normally biased open, but which closes in response to being contacted by a rack of foodware items when moved by the conveyor 18 into the rinse station 16. Thus contact with the detector 20 by a rack energizes rinse pump 24 to supply rinse solution from tank 22 to the rinse arms 30 and 32 in station 16 for spraying the solution 26 onto the foodware items to rinse and chemically sanitize them.

#This form of the batch rinse system further includes a source of chemical sanitizing agent such as a bottle 34 of 5.2% sodium hypochlorite solution, a sanitizer pump 36, such as of the peristaltic type, a source of fresh water (represented by pipe 40), means for admitting water in the form of a solenoid water valve 42, and a pressure regulating valve 44 (or some other suitable flow control device) in the fresh water line 40. Box 46 represents the electrical connections between various of these components, which will be described in detail with reference to FIGS. 4A-4F. The rinse solution mixing tank 22 has lower and upper solution level detectors in the form of a pair of floats 48 and 50 mounted therein, as depicted in FIG. 3B, which are raised and lowered by the solution level in the tank 22 and, in turn, open and close respective switches 52 and 54 disposed adjacent to, and connected with, the respective floats 48 and 50. Each float and switch combination may be devices similar to a liquid level switch, part no. 650-P, commercially available from Compac Engineering, Inc. of San Jose, Calif.