Classification and comparison of pellet mills

As we all know, pellet mills are divided into two series - flat die series and ring die series.

Everyone should be familiar with the ring die series, because many feed companies at home and abroad use ring die machines for granulation. Since the raw materials for feed are all concentrated materials, such as corn, soybean meal, cotton meal, etc., the bonding rate is high, and a steam conditioner is equipped before pelleting, which can soften and ripen the materials in advance, so as to better granulation, and increased the gloss of the granules. However, crude fibers such as straw and wood chips have low bonding rate and are difficult to form. If they are used as fuel particles, they require a large density, so a lot of pressure is required to achieve the density of the particles, which increases invisibly. difficulty. Due to the gradual rise of renewable energy in recent years, the ring-die granulator for fuel pellets currently on the market has evolved from the ring-die machine for feed, so there are still many drawbacks that we need to improve.

Flat-die series granulators are generally divided into two or more parallel-roller granulators in China, which are mainly used for organic fertilizer granulation. For example, fuel pellets can be made, but the wear and tear of the machine is great, which increases the cost, so it is not suitable. In response to this problem, on the basis of learning from foreign advanced technology, our country has developed a conical roller granulator, which is different from the two-roller series in the following points:

1. Conical pressure rollers are used, and the two ends are the same as the inner and outer circles of the die plate. There is no dislocation friction between the wheel and the die, which reduces resistance, reduces kinetic energy loss, prolongs the service life of the die, and reduces production. cost.

2. There are three observation doors in the granulation room, and the materials can be cleaned at any time, which is convenient for equipment maintenance.

3. The pressure rollers are evenly arranged, and the operation is stable. At the same time, the pressing area is increased to improve the production efficiency.

4. The screw center pressure regulating structure is adopted, and the gap between the molds increases and decreases, so as to adapt to different materials and ensure the pressing effect.

What is the difference between the two series of machines when it comes to making fuel pellets?

1. Feeding method: The ring die granulator adopts mechanical forced feeding, high-speed rotation and centrifugal distribution into the granulation chamber, and the material is distributed by the scraper, and the feeding is uneven; the flat die granulator is vertically fed by the weight of the material itself. Pressing chamber for even feeding.

2. Pressure: In a mold with the same diameter, the diameter of the ring die pressing wheel is limited by the diameter of the ring die, so the pressure is limited; the diameter of the flat die pressing wheel is not limited by the diameter of the die, and the built-in bearing can be increased. Space, large bearing is selected to enhance the bearing capacity of the pressure roller, which not only improves the pressing force of the pressure roller, but also prolongs the service life.

3. Discharging method: the ring die has a high speed, and the breakage rate is high when the material is discharged; while the flat die has a low speed and a low breakage rate.

Fourth, the adjustment method of the pressure wheel: the ring die granulator uses two screws on the eccentric wheel in the middle of the pressure wheel to adjust the pressure; the flat die granulator uses a central adjustment mechanism of threaded screw rod m100, the top force is 100 tons, and the falling Smooth, soft touch and even pressure. There are two ways of rotating manual and hydraulic automatic adjustment.