Application of KE300A Frequency Converter in Jaw Crusher

1. Overview

Crushers are widely used in mining, smelting, building materials, highways, railways, water conservancy and chemical industries and many other sectors. The crusher is mainly used for crushing various types of stones. According to different crushing principles and different product particle sizes, it can be divided into many models. Currently commonly used crushing machinery includes jaw crusher, impact crusher, winnowing crusher, hammer crusher, impact crusher, roller crusher, compound crusher, etc.

The electric charge of crushing electrical and mechanical equipment in the concentrating mill is relatively high, generally accounting for 40% to 60% of the total cost of the concentrating mill. Therefore, to improve the production efficiency of the crusher, reduce the unit energy consumption, and reduce the cost, the use of high-efficiency and energy-saving crushing equipment is the main means.

2. Working principle of the jaw crusher

The crushing method of the jaw crusher is the curved extrusion type. Its working principle is: the motor drives the belt and the pulley, and the movable jaw swings back and forth through the eccentric shaft. When the movable jaw pushes the movable jaw plate to the fixed jaw plate, the material will be crushed or chopped. When the movable jaw and the movable jaw plate retreat under the action of the eccentric shaft and the spring, the objects that have been broken into pieces are discharged from the lower discharge port of the jaw plate. With the continuous rotation of the motor, the mobile jaw of the crusher periodically crushes and discharges materials to realize mass production.

3. The problems of traditional power frequency control

(1) Low efficiency and relatively large energy consumption.

Traditional power frequency control cannot adjust the speed according to the working conditions. When the size and quantity of imported materials are different, the crusher always runs at a high speed, which will easily cause uneven crushing of materials and waste of energy.

(2) The start-up inrush current is large, which is easy to reduce the motor insulation and damage the electrical components, and the maintenance cost is high.

Most of the crushers adopt the method of power frequency direct start or self-coupled step-down method, so that the starting impulse current is large, and the requirement for the front-end transformer capacity increases. The frequent start and stop will also cause great impact and wear on the equipment, which affects the performance of motor and electrical components and shortens theirs service life.

(3) Poor automatic protection.

In the crushing process, when the stone is stuck, the current increases and the immediate protection cannot be achieved. Then the contactor will be burned out immediately. If it is serious, even the motor will be burned out, which will increase the cost of equipment maintenance.

(4) The power factor is low. Generally, the power factor is very low at a light load.

The power factor is low, and the reactive power consumption is too large, which increases the power loss inside the transformer and related electrical equipment network, and directly increases the expenditure of electricity costs. Accelerated aging of equipment will easily shorten the service life of the equipment and affect the operation of the equipment. China's electricity supply rules stipulate that all users whose power factor does not meet the above requirements will be charged additionally by the electrical industry department: power rate electricity fee (fine).

4. The characteristics and advantages of the transformation plan

Frequency conversion control technology is the most important technology of current electrical automation control. It has already played an important role in equipment control in all walks of life. It is an inevitable development trend for the application of crusher, and it will definitely become the most important and central part in the automation of crushing process control. The use of frequency conversion control technology for the crusher will bring about the following innovations: