light industry

1、preface
For a long time, chemical, cement and ceramic industry commonly used ball mill grinding of raw materials, it generally uses the frequency sensitive variable resistance step-down start way, material is easy to be caused by excessive grinding, grinding cycle is long, low grinding efficiency, power consumption per unit of product, high starting current, impact of equipment and power grid, electrical equipment maintenance quite troublesome, carbon brush and slip ring and ball fork and movement of the contactor contact almost every a period to carry out replacement or maintenance. (such as slip ring such as burns also lathe) so that not only the electrical technicians feel a headache, but also the serious influence production, under the low voltage could not start. And the amount of electric power loss is quite amazing, this is bound to bring a lot of unnecessary trouble and serious waste of resources to the manufacturer, so with the expansion of the economic and social development and the production scale of enterprises, direct control of the ball mill ills have been exposed and seriously hindered the industrial enterprise rapid development. This has prompted the people to develop a smooth, high grinding efficiency, large output, low energy consumption of the ball mill - that is, variable frequency speed control system.

2、Main structure
The ball mill is mainly composed of a transmission device, a cylinder device, a feeding device, a discharging device and an electric control device.

3、working principle
The ball mill is made up of the main parts of the feeding part, the discharging part, the rotating part and the transmission part (the speed reducer, the small transmission gear, the motor and the electric control). Ceramic industry has a horizontal cylinder body, cylinder body is partition (drilling has many small hole circular plate, plate) is divided into 2 to 4 in the grinding chamber, each of the grinding chamber is provided with a certain shape and size of grinding body, cylinder rotates, the material and grinding body under the action of centrifugal force and friction is cylinder is lifted to a certain height, then under the action of gravity along the approximate parabolic trajectory falling impact and grinding at the bottom of the cylinder body of another part of the material and produce certain axial movement which makes the material grinding and mixing. From the process of classification, there are two kinds of dry grinding and wet grinding.

4、Electrical basic control device
Ball mill used for the majority of frequency sensitive rheostat as starting device, (relative to the series resistance box is much smaller, on resistance box is mainly used in occasions speed, step by step short resistor to achieve speed control purposes) when the moment of starting on the impact of the power grid, and starts after the completion of the operation required torque decreases, so in the field of energy conservation has a lot of space.

5, transformation program
According to the problems existing in the original working conditions and the requirements of the production process, after the transformation of the ball mill system should meet the following requirements.
(1) after the transformation of the equipment to enough starting torque, meet the ball mill load of, and ensure the equipment in the running state of the inverter to the smooth operation of the motor, to protect the motor has the characteristics of constant power.
(2) the use of frequency conversion control system transformation of original ball mill drive system, normal operation with the ball mill at low speed to ensure normal process control, to extend the service life of the ball mill and the motor, reduce maintenance.
(3) after the transformation of the equipment to achieve automatic control, and manual / power frequency and fault self switching and other functions, and can overcome the large inertia of the ball mill to cause recovery voltage, effectively ensure the normal operation of the equipment.

6, frequency converter selection
According to the above principles, Yi Chong Fei ECF100Q-T3-###QK series of ball mill is a special frequency converter, so that the system can meet the requirements of the above conditions.

7, Q series inverter characteristics
(1) to meet the low speed operation of the ball mill, large starting torque characteristics, to achieve a continuous adjustment of the running speed of the ball mill. When the motor starts, there is no impulse current, the dynamic distance is enough, and the protection function is perfect. To ensure the quality of the process control, saving the cost of maintenance.
(2) there are some customers with other brands of general-purpose inverter for transformation, but the effect is not very ideal. And David chuangfei electrical according to years of experience in the transformation, the use of ECF100-T3-Q series of ball mill is a special frequency converter internal self setting V / F curve to optimize the starting and accelerating performance. V/F curve for the working characteristic of the ball mill itself is debugged. It is proved that the operation is stable and reliable.