Ball-Tube Mills This type of mill consists of a rotating tube filled with cast alloy balls. Coal is introduced through two hollow trunnions on each side of the tube. As the tube rotates, the balls tumble onto the coal, crushing and pulverizing it.
Ball and tube mills A ball mill is a pulverizer that consists of a horizontal rotating cylinder, up to three diameters in length, containing a charge of tumbling or cascading steel balls, pebbles, or rods.
A coal pulverizing system with ball-tube mill and storage bunker amount inside the milL This variable is very important. There is a critical value of this variable. If the coal amount in the mill is less than this critical value, then the plant is self-balanced. and Ille more coal amount, the more pulverized coal generated, thus the higller .
manufacturers of coal pulverizing equipment. The four most common types of coal pulverizers are: Ball-Tube Mills This type of mill consists of a rotating tube filled with cast alloy balls. Coal is introduced through two hollow trunnions on each side of the tube. As the tube rotates, the balls tumble onto the coal,crushing and pulverizing it .
Stable control of a coal-pulverizing system with ball-tube mill usually cannot be hold due to some disturbances, such as coal hardness and steel ball wearing, etc. A hierarchical structure with a .
Figure 4 compares a conventional vertical table type pulverizer with a ball tube mill pulverizing system with crusher dryer. The table type pulverizer allows high temperature air to reach the coal charge. The ball mill system with crusher dryer normally reduces the inlet temperature to less than the auto ignition point of the coal charge.
Coal pulverizing system explosions during the last few years have pointed to the need of developing inerting systems for preventing such incidents. The greater use of western subbituminous coals (with their higher tendency for spontaneous ignition) is a contributing factor to the increased frequency of coal pulverizer explosions.