Flat die feed pellet machine and ring die feed pellet machine are two types of pellet machines on the market. What is the difference between the two pellet machines? First let us understand the functions of flat die feed pellet machine and ring die feed pellet machine.

Working Principle of Flat Die Pellet Machine

Flat die feed pellet machine is the first pellet machine design based on flat die in the early 20th century. Generally, there are two types of flat die feed pellet machines on the market, rotary model and rotary roller type. The former has a fixed roller with a rotating die, while the latter has a fixed die with a rotating roller. Adopting the vertical principle, the raw materials fall into the pelletizing chamber by their own weight, where the raw materials are compressed between the rollers and formed into pellets through the die holes.

The advantages and disadvantages of the flat die pellet machine are as follows:

Due to the compact structural design, the flat die pellet machine is small in size and light in weight.

Due to the design of portable rollers and dies, the flat die pellet machine is easier to clean and maintain, and is inexpensive.

The flat die pellet machine makes it more convenient for you to monitor the pelletizing process by observing the pelletizing chamber, which makes it easier to conduct raw material expansion experiments for uncertain materials.

The disadvantage of pellet mills is that they are not suitable for large-scale pellet production. The gap between the roller and the die is also tricky and should be adjusted according to the type of raw materials, especially the hardness of the raw materials.

In summary, in small-scale and medium-scale pellet production, flat die pellet mills are generally used to process materials with greater adhesion of fuel pellets and feed pellets. Compared with ring die pellet mills, they are known for features such as reliable operation, greater mobility, lower noise, lower energy consumption, and relatively low productivity.

Working Principle of Ring Die Pellet Mill

The ring die pellet mill was designed around the 1930s based on the design of the ring die. The basic pelletizing principle of the ring die pellet mill is a simple operation in which the feed is distributed on the inner surface of the rotating perforated die before each roller, compressing the feed and compressing it into the die hole to form pellets.

The advantages and disadvantages of the ring die pellet mill are as follows:

The ring die pellet mill produces less wear because the inner and outer edges of the rollers traverse the same distance.

The ring die pellet mill is more energy-efficient than the flat die pellet mill.

One problem with ring die pellet mills is side slip. Side slip is an indisputable fact on ring die pellet mills. It refers to the sideways extrusion of feed paste from the nip between the roll and die, which can be minimized depending on the configuration of the die. One way to do this is to expand or drill a larger hole in the two outer rows of the die to reduce the friction caused in the hole.

In short, ring die pellet mills can also be used to produce fuel and feed pellets. However, compared with flat die feed pellet mills, ring die feed pellet mills are known for their large pelletizing capacity. They have the characteristics of large capacity, good pellet forming, high density and high energy consumption.

The comparison between flat die and ring die feed pellet mills differs in the following aspects:

1. Price: Flat die feed pellet mills are much cheaper than ring die feed pellet mills.

2. Production capacity: Flat die pellet mills have a production capacity of 80 to 1000 kg/h, while ring die pellet mills have an output of 0.8 to 2 t/h.

3. Feeding: The feeding of the flat die feed pellet machine depends on the weight of the material, and the raw material enters the pelletizing chamber directly and evenly. While feeding the ring die pellet machine, it is sent into the pelletizing chamber and distributed by the high-speed rotating scraper.

4. Pressure: The pressure of the flat die pellet machine is adjustable. The diameter of the roller in the flat die pellet machine is not limited by the diameter of the pellet die, so the roller pressure can be increased by expanding the internal bearing space, and the use of large bearings can also extend the service life. For the ring die pellet mill, since the diameter of the roller is limited by the diameter of the pellet die, the pressure of the pinch roller is limited.

5. Discharging: Due to the high rotation speed of the ring die, the damage percentage of the flat die pellet machine is lower than that of the ring die pellet machine.

6. Formation of pellets: The flat die type has a circular perforated disk, on which two or more rollers rotate and force the material through the holes to form pellets. The ring die press has a rotating perforated ring, on which rollers (usually two or three) press the material to the inner circumference to form pellets.

By comparing, the characteristics of these two different pellet mills are obvious. When purchasing a pellet mill, you need to consider the overall situation of your pellet production and find the right feed pellet mill.