Improvements in and relating to dish washing machines

摘要

1,068,541. Dishwashing machines. CHARLES COLSTON Ltd. Dec. 23, 1964 [Jan. 3, 1964], No. 432/64. Heading A4F. [Also in Division B2] A dishwashing machine comprises a washing chamber C, Fig. 1, through or within which, in operation, washing liquid is continuously circulated, means to withdraw a proportion of the liquid in circulation and by centrifugal means 7 to separate the withdrawn portion into relatively soilfree and soil-rich fractions, the soil-free fraction being returned to the washing chamber and the soil-rich fraction isolated for further treatment or discharge. The chamber C is provided with a door to enable articles to be washed to be placed on racks R and a pump P draws liquid from a sump S having a filter F for delivery through a duct M to a spray T. The duct M is also connected by a pipe 9 to an inlet 8 of a cyclone 7 having an outlet 10 connected by a pipe 11 to the chamber C to direct or spray soil-free liquid to parts of the articles not reached by the spray T. The cyclone also has an underflow outlet 12 for supplying soil-rich liquid to a settling chamber 13 having an outlet 14 connected to a length of rubber tube 15 in a chamber 16 conected by a pipe 17 to the pump P, the pressure from the pump acting to contract the tubing during operation to prevent the soil-rich liquid from passing to a drain 18. When the pump is stopped, the tubing opens to let the liquid in the tank 13 pass to the drain with the liquid from the chamber C. The tube 15 may be closed by the return of the liquid moving a plunger towards an anvil against which the tube rests. The liquid in the settling tank may pass through a fine-mesh screen back to the chamber C. In a further embodiment, the inlet (8) of the cyclone 7 is connected by a pipe (91, Fig. 3) to the duct (M) from the pump (P) and has its outlet (101) connected by a pipe (111) to the washing chamber. The underflow outlet (121) is connected to a diffusing cone (30) in a settling tank (131), the upper end of which is connected by a flowrestricting device (28) to the washing chamber and the lower end of which is connected by an outlet (141) and pipe (151) to a drain valve (27). The flowrestriction consists of a chamber having a tangential inlet passage and an axial discharge passage. In a further embodiment, two or more cyclones are used in series, the underflow of the first being discharged into the inlet of the second.