Influencing factors and improvement measures of hammer mill screen affecting feed mill grinder capacity

1. Hole arrangement of grinder sieves
The arrangement of sieve holes in chicken feed mill crusher includes horizontal row holes and vertical row holes, all of which are equilateral triangles. The grinder sieve of the horizontal row of holes is the material running direction perpendicular to one side of the triangle. The vertical row of holes is the material running direction parallel to one side of the triangle. When selecting a large-aperture sieve (aperture>Φ4.0), the way of arranging holes has no effect on the production capacity. Due to the high production capacity and the impact of the material on the sieve of poultry feed hammer mill, the vertical row of sieve is easy to choose. The vertical spacing between the two holes just forms a strong support for the crusher screen. When the grinder sieve with small aperture is selected (pore size ≤ Φ4.0), the reduction in the overall production capacity of the material also reduces the impact on the grinder screen. Therefore, horizontal holes with no material incident blind area should be used. Practice has proved that when using screens with small apertures, under the condition of the same opening rate and the same thickness, the capacity of screens with horizontal rows of holes is 5%-10% higher than that of screens with longitudinal holes.

2. Opening ratio of feed mill hammer mill sieve
When selecting the feed milling sieve, give priority to meeting the requirements of the product size, and then select the sieve with high density and large aperture as much as possible according to the strength that the sieve can withstand. The relationship between the sieve hole diameter and the crushing particle size is roughly: the strength of the finished product ≈ (1/4-1/3) sieve hole diameter. At the request, we have achieved a Φ2.0 sieve with an opening rate of 45%. The problem is that the opening rate of the sieve is increased, the powder output efficiency is also improved, but the impact value of the feed crusher sieve is reduced. The cleaning of raw materials can not be absolutely clean. Some large sand and gravel can easily break the sieve and produce back to the machine material, which increases the production cost. After many tests, on the basis of ensuring the original 42% high aperture ratio, the aperture on the back of the screen was increased while the aperture on the front of the screen remained unchanged. A kind of material guide hole similar to the feed pelletizer ring die is formed. During use, the burr surface should face the rotor. In the direction of the material flow, when the material collides with the corners of the burr surface when passing through the sieve hole, it can play the role of friction and crushing, and can increase the sieving capacity. At this time, the angle of the bell mouth increases the feeding angle of the material, which just plays a role similar to the guide hole of the ring die, and the crushing efficiency is significantly improved compared with the original screen.

3. Installation of grain grinder sieve
When the corn grinder sieve is installed, a crusher sieve with a hole size required for the material size is installed on the front side, and a crusher sieve with a larger size is installed on the back side, which can not only meet the particle size requirements of the material but also improve the crushing efficiency. When the corn hammer mill screen is punched, micro-dents will be formed on the positive side, the circumference of the screen hole becomes smooth and dull, and the cutting ratio decreases. If the sieve is installed with anti-burr facing outwards, it will also cause hanging material at the burr to block the sieve hole and affect the powder output efficiency.

4. Failure of crushing sieve
Most of the damage to the soya bean grinder screen is broken by foreign objects entering the crushing chamber. Small holes can be reused after welding repair. When multiple holes appear, the effective screen area of the repaired screen is greatly reduced, and then repaired The use value is lost, and only a new sieve can be replaced. When comet pits appear in the sieve hole, the cutting ratio decreases and the powder speed becomes slower. Even if there is no foreign matter hitting the damage, this milling sieve should be replaced. If it is used again, the wasted power consumption will far exceed the residual value of the sieve. .

5. The impact of temperature rise on production capacity during crushing
The first-line employees who know about crushing may have encountered such a phenomenon. When the crusher started working, the crushing speed was very fast. After working for an hour or two, the crushing speed tends to decline slowly. In particular, this phenomenon is more obvious when making small-aperture sieve for pig feed and fish feed. After the reversing of the crusher, the production capacity returned to the state of high production capacity. That is because after the crusher has been working for a period of time, the heat generated by the hammer hitting the material and the heat generated by the friction of the material against the screen cause the temperature of the crushing chamber to increase. The sieve is in such a harsh environment for a long time, and the fatigue strength, surface hardness, and cutting strength decrease, which directly leads to a decrease in the powder output rate. At this time, it is best to stop feeding and let the crusher idle for a few minutes. In a few minutes, under the action of negative pressure, the temperature of the crushing chamber can be lowered, and the production capacity can be restored.