| MPS secondary-speed coal pulverizer is a kind of entering-force coal pulverizer. The electromotor drives the millstone to turn through the main speed reduction machine, and the turning of the millstone drives the three abrasive rollers (They are distributed uniformly by ) to turn round themselves. The raw coal drops into the millstone through the coal-entering pipe and moves to the brim of the millstone along the radial at the action of the centrifugal force. Then it moves into the roller path of the millstone and is milled between the abrasive roller and the millstone tile. The whole milling system is blocked in a frame. The milling pressure and the weight of the milling components all act on the speed reduction machine, and are transmitted through it to the base. The three abrasive rollers are distributed at the roller path of the millstone uniformly, and are fixedly to the loading rack. The loading rack and the abrasive roller bracket can swing along the radial through the fixed roller with the incline degree being . It is in order to adapt the variation of the materiel layer ply and the variation of the angle caused by the wearing between the abrasive roller and the millstone tile. In this paper, we discuss the design calculation expressions and the design methods according to the MPF2116 coal pulverizer. The content of the design calculation contains: the parameters calculation of the coal pulverizer, the structure dimensions of the major parts and the type-choosing calculation. The calculation results will be the design gist of this standard coal pulverizer. In this paper we do some researches on the secondary-speed coal pulverator, MPF2116, and carry out the simulation experiment with SIMULINK. The Hard agrindability coefficient of the milled coal is 64, the percent of ash is 30%, and the percent of water is 8%. We also study the disturbing experimentation about the variation of the entering coal capacity, the simulation of the fired fault, and so on. These researches indicate:(1) As changing the supplying coal capacity, the mass equilibrium inside the mill is broken off, the mass inside the mill changes, and correspondingly the sending-out force of the mill changes. After a period of time, the sending-out force will be equal to the supplying coal capacity, and the deposited coal inside the mill will not change any more, the mill will function in a new steady work condition. The MPS mill usually uses in the straight-blowing milling system. When changing the boiler's fuel, it is need to change the coal supply machine's velocity to change the supplying coal capacity, then sending-out force of the mill changes, which needs a certain delay time (the time in this simulation is 200s.). The boiler of middle storge milling system can adjust the fuel by changing the speed of coal supply machine, which is not delay at all. (2) When the temperature of the place with an entering draught changes, the temperature at the exit of the mill will change rapidly. And it needs a period of time to make the temperature at the exit achieve a steady state.(3) When the mill occurs the fired fault, the temperature at the exit of the mill will arise rapidly.(4) The simulation in this paper indicates that the millstone is also frayed. If the roller sheath and the liner tile are frayed, the compressing measure of the spring at the upside of the abrasive roller will change with the loading force changing also. This will cause the descent of the sending-out force of the mill. If remaining the rated supplying coal capacity here, it is possible to jam the mill. Since the abrasion happens by inches, so in the simulation, we consider the abrasion of the parts of the mill to be an external variable, and to show the abrasion of the parts of the mill by setting the parameters.(5) In the simulation experiments, we consider that the coal powder fineness keeps invariable. In actual function, the fineness changes with the variation of these factors: the opening degree of the folded door in the separator, the milling... |
