Analysis of common failures of hammer mill

Hammer shredders are widely used in the crushing of grain and feed. The causes of several common faults of the shredders are analyzed as follows: 1. Causes of severe wear of the hammer shingles: ① Improper surface heat treatment, because the hammer shingles are made of high-quality steel. The head is carburized and quenched, and the quenching hardness is HRC60 ~ 65. If the heat treatment is improper, it will wear quickly during use. ②The thickness of the hammer piece is small. Because the crusher usually uses rectangular double pin hole hammer pieces, its service life It is 200 to 500 hours. Although the thickness is small, it can reduce the weight and increase the crushing productivity, but the service life is short. Generally, the hammer blade for crushing grain is 2 to 3 mm, and the crushing bean cake and minerals are 6 to 8 mm. As the hammer blade crusher generally adopts air suction measures to reduce the temperature and humidity inside the machine and prevent dust from leaking out, but the large suction volume will also cause uneven wear of the hammer blade, and the air volume should be properly controlled; ④ hammer blade and sieve The gap between the pieces is too small, generally it should be kept at 4-12mm, the crushed grain is 4-8mm, and the crushed straw is 10-14mm. 2. Reasons for vibration and noise during machine operation: ① The machine base is not firmly installed and the fastening screws are loose; ② the hammers are not replaced in pairs at the same time, or the hammers are not worn uniformly, causing the weight of the hammers to vary greatly; The rotor rotates unbalanced and the rotation speed exceeds the rated rotation speed; ④ foreign materials such as stones or metals are mixed in the material to cause noise, and at the same time, the hammer and sieve will be damaged. 3. Reasons for the significant reduction in productivity: ① insufficient motor power or inappropriate power; ② the rotor speed is too low or the belt is slipping, check the size of the pulley to meet the requirements, or adjust the belt tightness; ③ uneven feeding speed makes the speed of the crusher Instability leads to a decline in productivity; ④ The hammer blade is severely worn, and the gap between the hammer and the screen is too large; ⑤ The water content of the material is too high. 4. Reasons for excessively thick finished products: ① the sieve plate and the sieve frame are not tightly fitted or the side gap is too large; ② the sieve plate is severely worn or has holes, and the holes should be repaired or replaced with new ones.