The machinery is consisting of the drum washer. The chips are fed in the tank of the washer which is full of water. The drum washer is installed in the tank and there are paddles on the drum. With the function of paddle and drum, the chips are washed in the water. After water separates the sand and metals, the chips move out from the tank. The sand and grid drop down into the tank and will be collected by the collector. The collector is made of two air valves and a middle deposit pipe. The top valve opens and the bottom valve closes during the machine working process. When it goes to clean the sand and grid, the top valve closes and the bottom valve opens. There are two inlet of the water feeding, one is in chips inlet and another one is in the bottom of  the washer tank to prevent the chip deposit down. The chips go into the next process after washing.