The invention discloses a pellet
coating system based on double PID adjustment, and relates to the field of
slurry preparation, the pellet
coating system comprises a stirring kettle which is communicated with a water inlet pipeline and a limestone feeding pipeline, and stirring blades in transmission connection with a stirring motor are arranged in the stirring kettle; the water inlet pipeline is provided with an
electric control valve, the limestone feeding pipeline is provided with a
mass flow meter, and a concentration sensor is arranged in the stirring kettle; the main
control unit comprises a main
PID controller and an auxiliary
PID controller, the concentration sensor is connected with the input end of the main
PID controller, the output end of the main PID controller is connected with the electric adjusting valve, the power
signal output end of the stirring motor is connected with the input end of the auxiliary PID controller, and the output end of the auxiliary PID controller is connected with a parameter setting interface of the main PID controller. The invention further discloses a control method of the
system, the proportionality coefficient or integral
time parameter of the main PID is dynamically adjusted, and concentration adjustment
lag caused by limestone feeding fluctuation or
slurry characteristic change is remarkably reduced.