Suote Hongfa Engineers Provide Professional Answers: Why Do Some Charcoal Machines Produce Cracked Fuel Rods During Production, and What Causes the Cracks?

    We approach this issue from a mechanical perspective. Wood Chips are subjected to two types of forces in the molding cylinder. One is the driving force transmitted by the motor through the screw rod; the other is the resistance force from the inner wall of the barrel pressing against it. Under normal conditions, the driving force is greater than the resistance. The greater the driving force, the faster the rods are produced. Density, however, is proportional to resistance – the greater the resistance, the greater the density.

To maintain a sufficiently large driving force relative to the resistance, two approaches can be taken. The first is to ensure the radial clearance between the barrel and the screw. Generally, the smaller the clearance the better; theoretically, no clearance at all is ideal, but this is impossible. A clearance of about 1mm is already very good. However, some barrels are bell-mouthed, in which case the clearance should be based on the frontmost ring of the screw. The second approach is to reduce the resistance, which is what the heating ring does. When the clearance between the screw and barrel becomes larger, we can use the heating ring to increase temperature and lower the resistance, which can also produce rods. However, because the resistance is reduced, the density of the rods is not as good as before. When the resistance becomes too low, the rods will develop cracks or fail to form properly.