axially formed with the washing dehydrating tank 1 around the upper periphery of the tank 1 and a reference character u201c 7 a u201d is an annular opening formed on the inner wall of the annular drainage pipe 7 a bottom plane 7 b of the annular drainage pipe 7 forms an inclined plane inclined toward a side pipe 8 which is explained below the above mentioned drainage plate 1 b is fitted in the annular opening 7 a the washing dehydrating tank 1 and the annular drainage pipe 7 are arranged so as to attain the above described fitting in relation a reference numeral u201c 8 u201d is the side pipe linking the annular drainage pipe 7 with a three way branched pipe 18 which will be explained below for circulating washing water flowing from the washing dehydrating tank 1 via drainage openings la and the annular opening 7 a into the annular drainage pipe 7 to the washing dehydrating tank 1 a reference character u201c 1 c u201d is convex columns with a semicircular cross section arranged on the inner wall of the washing dehydrating tank 1 six convex columns 1 c are circularly arranged with a 60 degree angled pitch although it is not illustrated a means for preventing the washing dehydrating tank from vibrating is also arranged when the washing is unevenly placed during the dehydrating operation a reference numeral u201c 9 u201d is loosners for loosening the washing.