GB640944A - Improvements in and relating to dishwashing apparatus - Google Patents

Abstract

640,944. Dish washing machines. BRITISH THOMSON - HOUSTON CO., Ltd. Aug. 25, 1947, No. 23450. Convention date, Aug. 24, 1946. [Class 138(i)] A dish washing apparatus comprises a vat having an upright side wall and a bottom wall, an impeller with a vertical axis of rotation in the lower part of the vat for forcing cleansing liquid contained therein upwardly and outwardly toward the side wall with a generally rotary motion, about the axis of the impeller, and a perforated cylindrical screen surrounding the impeller with its lowermost edge on the bottom of the vat, and disposed in the path of the cleansing liquid entering the impeller, the bottom wall being formed with an annular depression which surrounds the perforated screen, has a lowermost portion spaced radially from the screen and below the level of the lowermost part of the impeller and constitutes a centrifugal separation sump for separating food particles and the like from the cleansing liquid, the latter rotating in the sump prior to passing through the screen into the impeller whereby the food particles suspended in the liquid move outwardly under the action of centrifugal force to the outer wall of the sump. As shown in the Figure, an impeller 13 is mounted above a re-entrant conical portion 11 of an annular depression 9 formed in the bottom wall 6 of the vat. The impeller 13, which is preferably constructed and arranged in the manner disclosed in Specification 557,034, is surrounded by a perforated cylindrical barrier 36 mounted on the portion 11 and held secure therewith, by a wire framework comprising a ring 36b centred by radial wires 36c. The top edge of the cylindrical barrier is arranged to be coincident with the level of the free liquid in the vat. Centrifugal action causes food particles 39 to be separated from the washing liquid before it is recirculated, but this separation is not so complete as to warrant the omission of the cylindrical barrier.