A slurry dilution valve is arranged on the slurry inlet pipe before the slurry pump.

The technical scheme adopted in the control system of the upflow pressure sieve is that the slurry tank is connected with the inlet of the upflow coarse body through the slurry pump, and a slurry dilution valve is installed on the inlet pipeline before the slurry pump, and a slurry concentration meter, a slurry inlet valve, a slurry pressure gauge and a slurry flowmeter are arranged in turn on the inlet pipeline after the slurry pump according to the slurry flow direction. The slurry dilution valve, the slurry concentration meter, the slurry inlet valve, the slurry inlet pressure meter and the slurry flowmeter are respectively connected with the PLC control device.

There are good pulp pressure gauge and good pulp valve in the fine pulp output pipeline of the upflow coarse sieve body in turn according to the flow direction of the fine pulp, tail pulp flowmeter and tail pulp valve in the tail pulp output pipeline of the upflow coarse sieve body in turn according to the flow direction of the tail pulp, heavy slag valve in the heavy slag output pipeline of the upflow coarse sieve body, and the upflow coarse sieve capital. The dilution pipeline on one side of the body is also connected with the up-flow coarse sieve dilution valve. The fine sieve pressure gauge, the fine sieve valve, the tail slurry flowmeter, the tail slurry valve, the heavy slag valve and the up-flow coarse sieve dilution valve are respectively connected with the PLC control device. The electric current meter is connected to the electric circuit of the motor connected with the rotating shaft at the bottom of the up-flow coarse sieve body. The meter is connected with the PLC control device.