Domestic dishwasher with variable cleaning of articles being washed

摘要

The dishwasher (10) has a sensor which measures the clarity of the wash water leaving the surfaces of the articles being cleaned before a filter and recirculation pump feeding the spray arms beneath the crockery baskets. A drain pump partly empties water from the same area, and refilling to the original level, before and after measurements are taken and difference in turbidity evaluated. Partial drain and fill continues until predetermined differences occur. The dishwasher consists of pair of baskets (14,16) into which crockery, cutlery and cooking utensils are placed, to be cleaned by jets of water from rotating spray arms (26,28) pressurised by a circulation pump (20) when container (12) is charged with predetermined quantity of water. The particle-laden water enters a space (30) and passes through a filter (34) into a space (32) leading to the circulation pump. A turbidity sensor (50) in the space before the filter assesses the clarity of the water at regular intervals after which a drain pump (38) removes a certain amount of water which is replaced by fresh water and turbidity measured again. The difference between the two readings is a measure of cleanliness of washed articles and determines the duration of wash process.