Ring die is the vital component of wood pellet machine. Its working performance and service life affect the electricity consumption, output and pellet quality directly. According to the incomplete statistics, the cost of wear and tear of ring dies usually counts for 25% of the plant’s total maintenance expenses. So choosing the right ring die is the key to save the cost and profit-making.
Choice of Ring Die for Wood Pellet Mill
1. Choose the ring die according to the raw material and the output you need. Different raw materials require different die holes, porosity and compression ratio, and the ring die is much more suitable for large scale production.
2. Consider the materials that being used for manufacturing ring die. Generally, the ring die is made of carbon structural steel, alloy structural steel and stainless steel through forging, lathing, drilling, heat treatment, etc. Every process is so important that affects the service life of ring die, output and the pellet quality. For the raw material with high corrosivity, stainless steel ring die is a nice choice.
3. Roughness of die hole also affects the ring die quality. Excessive high roughness affects the shaping of wood pellets, even causes the blockage. If the die holes is drilled by multi-station gun drill, they will be more smooth to discharge the final pellets.
4. The clearance between roller and ring die has an important impact on the effective use of ring die. It is requisite to adjust the clearance between the die and roller to an appropriate range, which is essential to the final pellet products. Generally, the clearance between 0.1mm to 0.3mm is better, and for the new die and new rollers, the clearance should be larger.
5. Choose proper compression ratio of ring die. Generally speaking, the small ratio of hole depth and diameter can increase the output, reduce the power consumption, reduce the wear of ring die, while lower the hardness of the pellet and increase the percentage of powered pellets. If not, the density and pellet quality will be improved, while the production costs will be increased.
How to Maintain the Ring Die Perfectly?
1. If the ring die will be unused for some time, it is necessary to feed non-corrosive oil into the die to drive out the residues. If not, the heat of the ring die will dry and harden the residues, resulting in blockage when we use the pellet mill next time.
2. Check if there is bumps on the working surface of the ring die after being used for a period of time. If any, grind them off by angle grinder to prolong the working life of a ring die.
3. Immersing or boiling the ring die in the oil when the die holes are blocked. If the blockage still can not be eliminated, drill out the residues with an electric hand drill and then clean the die with oily material mixed with fine sand.
4. Filling the oil into die holes when we change the ring die.
5. Ring die must be stored in a dry and clean area in case of the corrosion and rustiness.