Main classifications of coal loading machines

　　Coal feederA coal feeder is a mechanical device that can accurately measure the amount of coal fed into the mill according to load requirements. The coal feeder is often arranged between the mill and the raw coal bin, allowing the coal feed amount to directly adapt to the boiler load. There are many types of coal feeders, which can be classified into gravity and scraper types based on their structure and working principle. Next, I will share the main classifications of coal feeders.

　　As mentioned above, coal feeders can be divided into volumetric coal feeders and gravity coal feeders based on their structural working principles.Coal feederIn applications, they are commonly divided into disc coal feeders and scraper coal feeders. The disc coal feeder can adjust the amount of coal fed by changing the rotation speed of the disc and the position of the inner sleeve. It can also change the coal feed amount by adjusting the angle of the scraper. Its structure is relatively compact and has good sealing performance. However, when encountering coal with high moisture content, it is prone to coal blockage and slipping.

　　The scraper typeCoal feedercan adjust the coal feed amount by changing its rotation speed and the position of the gate. It can be made into a fully enclosed coal feeder, which can be applied in various coal mines. However, it occupies a larger area, and during operation, if the coal is not compacted, the scraper may float and get stuck by stones or wooden blocks, leading to coal breakage.

　　The gravity coal feeder consists of two weighing supports and a belt installed inside the coal feeder shell, forming a weighing device. There is a weighing frame in the weighing block, equipped with a relatively precise sensor that can generate a load signal based on the unit channel strength of the coal feed and coal weight. Additionally, a photoelectric speed sensor is installed on the driving pulley, which can generate a speed signal. These two signals are output and calculated to determine the boiler combustion rate. If it does not meet the requirements, the belt speed can be adjusted to satisfy the corresponding needs.

　　Coal feederIt can also display the accumulated coal feed amount during a running phase with high measurement accuracy. The operation process is very reliable, and the size is relatively narrow, compact, occupying a small area, with good sealing performance, making it suitable for various advantages such as positive pressure and irregular shapes. It has been widely used in large boiler units.

　　In addition, there are electromagnetic vibrating feeders and belt feeders. Electromagnetic vibrating feeders have a simple structure, lightweight, no transmission components, and easy maintenance. However, they have significant air leakage in negative pressure systems, and the small coal bin at the inlet is prone to blockage due to large cross-sectional shrinkage. Belt feeders are less prone to blockage and have fewer failures, but they have significant air leakage, and coal with high moisture content and strong viscosity is prone to slipping on the belt. They are generally used in grinding systems of tubular mills with small inlet negative pressure.