How to solve or avoid sudden failure of coal mill equipment

How to solve or avoid sudden failure of coal mill equipment

Coal mill equipment is a relatively large proportion of equipment in the entire dressing plant, accounting for more than 50%. Therefore, ensuring the normal operation of the coal mill is a necessary condition to ensure the normal production of the entire dressing plant. However, when the coal mill is applied, some sudden failures often occur, which affects the production efficiency. So how to effectively solve or avoid these sudden failures? The editors sort out some sudden failures of coal mills and solutions for you.

Sudden failure of the coal mill is generally caused by multiple reasons such as long-term high-speed operation, job responsibility and improper operation.

In the entire system of the coal mill, there will be iron-containing dust in the air around the material. After a long period of operation, the iron-containing dust will adhere to the coil of the coal mill stator. When it reaches a certain thickness, it will cause A short-circuit discharge occurred on the surface of the stator coil. When the short-circuit phenomenon occurs many times, the insulation of the coil will be damaged, causing a fire and breakdown phenomenon, causing the coal mill to stop running. Without the backup motor, grinding work is difficult to continue. Therefore, we can relate this fault to the lack of cylinders in the car, and we can find a solution. At this time, the breakdown coil should be cut off immediately, and scientific protection measures should be adopted to restart the coal mill and production work can continue.

After the sliding shaft of the coal mill has been worn for a long time and reached a certain thickness, the spherical body of the coal mill is difficult to combine with the tile lining, and scratches will occur. In general, this kind of situation occurs mostly because the clinker temperature of the hollow shaft is too high, and the temperature of the outer surface of the hollow shaft is also high, resulting in the lubricant being too diluted and losing the viscosity, making it difficult to form a good oil film, causing the bushing and journal Friction generates heat and heats up quickly, causing the surface of the tile lining to be melted and scratched.

If there is no spare spherical tile, you can only stop and check, repair the tile surface and continue to use it. It can restore the smoothness of the surface of the scratches by frustration, cutting, grinding, etc., and the undamaged part needs to be scraped out a micro oil groove to repair the tile mouth, and the materials and grinding media in the coal mill are emptied. Manual method, rotating the barrel to carry out no-load grinding. When it reaches a certain level, it will be linked with the transmission part to carry out the no-load trial operation. Then, the materials and grinding media are loaded into the coal mill for load operation, so that the coal mill returns to normal. operation.

In the process of linking the barrel and the hollow shaft of the coal mill, the barrel needs to make a through hole with the flange, and the pin is connected by a screw buckle. The through hole only needs to be connected by ordinary screws, and the reaming hole is mainly used to limit Position and positioning.

After long-term operation of the coal mill, due to thermal expansion and contraction, distortion, high temperature corrosion, water vapor corrosion, etc., the matching size of the pin hole and the reaming hole will change, and the loosening phenomenon will occur, making it difficult to limit the position. Also due to twisting, the screw begins to loosen, causing periodic displacement of the barrel and the hollow shaft. If the screw is stretched for a long time, the screw will break.

According to many years of experience, after this kind of failure occurs, the screw can be changed to a hinge pin for connection. At present, there has not been a phenomenon that the hinge pin breaks.

During the operation of the coal mill, the head base slipped and the temperature of the bearing suddenly increased. This phenomenon is mostly due to the sinking of the head base part, the whole body of the mill moved forward and tilted. The spherical shoe shoulder and the flange root of the hollow shaft undergo squeezing contact and rotational friction, generating heat and causing the temperature to rise rapidly. This kind of situation may cause the coal mill to tilt. The meshing of the large ring gear and the pinion gear will form an axial angle, which cuts the teeth together, making the meshing difficult, resulting in a loud sound and increased vibration. In severe cases, the coal mill will be shut down. .

After this phenomenon occurs, it is necessary to stop and check, weld and lengthen the grounding foot bolts, wedging the horn, and raising the bearing seat, which can control the temperature of the sliding bearing and the sound of the transmission part.

The above 4 points are common sudden failures of the coal mill. When the problem is found, it must be analyzed and judged in a timely and accurate manner, and the corresponding treatment method is found according to the cause of the failure, so that the damaged parts of the coal mill are timely Repair and normal operation can ensure smooth production and reduce losses.

Hot Products