Speed Regulation of Ore Sand Pump by Cyclone in Concentrator

Date: 2021-08-14     From: Longding     Author: admin

In the grinding circuit, the control and speed regulation of the cyclone to the mine are the main elements that determine whether the product is qualified. The control of the cyclone feeding the ore depends on the operation mode of the ore feeding pump and the capacity of the pump pool. Therefore, the operation mode of the cyclone to the ore pump determines the overall control scheme of the grinding circuit.

With the change of feed rate or feed water rate, the feed quantity and feed particle size of the cyclone will change, which will change the particle size and concentration of the overflow product of the cyclone, so the entire loop is in a state of disturbance. Therefore, in order to meet the requirements for the regulation and control of the feed rate and water feed rate in production, sand pump speed regulation and corresponding control systems are generally used in the cyclone loop of the mill.

Speed regulation mode of cyclone feeding pump

In the grinding circuit, there are two main ways to adjust the speed of the ore pump by the cyclone: variable frequency motor speed control and hydraulic coupling speed control.

1. Variable frequency motor speed regulation

The relationship between the speed n of the frequency f, the number of pole pairs p, and the slip rate s is: n=60f/p(1-s)(r/min).

It can be seen that with the change of AC frequency, the speed of the motor changes proportionally. According to this principle of the AC motor, using a frequency conversion device to change the input current frequency of the motor can change the speed of the motor and achieve the purpose of speed regulation. The main disadvantage of variable frequency speed regulation is that the high-order harmonics generated by frequency conversion reduce the power factor of the motor and cause the motor torque to pulsate. Because the harmonic loss reduces the efficiency of the motor by about 3%-5%, the rated power of the motor should be appropriately amplified by 5% or more after determining the rated power of the motor, according to the operation mode of the transmission system and the nature of the load.

2. Fluid coupling speed regulation

The fluid coupling is a kind of power hydraulic transmission device that uses liquid to transmit power. It is mainly used in industry to connect two drive shafts as a flexible coupling and clutch. According to their different functions, fluid couplings can be divided into ordinary type, distance-limiting type and speed-regulating type. The speed-regulating fluid coupling can realize stepless speed regulation.