The invention belongs to a kind of installment which is used to separate and collect the precipitation solid particle from the liquid, Specially involves the collecting sink granulated substance installment in the sewage treatment.The invention discloses realized like this, it includes the driving car moves along the aeration sand collector, the driving car has the funnel uses to store the granulated substance, on the driving it establishes the runner, lower part is established with the runner, the upper runner and the under runner transmit through the link chain,the is a dig funnel on the chain link,the upper runner has a dive installment on it, Therefore it will be able directly dig out the sink granulated substance from the lower pond, the water content will be extremely low, work 30minutes every day will to be possible to complete the centrifugal pump 24hours work loads, therefore greatly enhances the working efficiency, reduces the equipment movement cost; Compares with the existed technology, the equipment attrition is slight,the energy consumption is few,the cost maintains to be low.Moreover,the moisture content of the granulated substance duged out is very low, did not need to enter the granulated substance water separator to separate, simplifies the craft, saves the equipment, saves the energy.