Coal Pulveriser Mills

Coal Pulveriser Mills

 How to debug Coal Pulveriser Mills

How to debug Coal Pulveriser Mills

1. High current of hot air blower.

When the inlet baffle of the hot air blower is opened to more than 30%, the motor current will exceed the rated value, and the system wind can not be pulled up. Because of the small air volume, the output can only reach half of the design value, and the fan vibration value is within the normal range, check the fan inlet baffle after the grinding is stopped. The opening of the plate is basically the same as that of the central control.

Solution: By adding frequency converter to the fan motor for frequency control, the shaft power of the fan and the output power of the motor are reduced, so that the motor current is controlled within the rated value, the system can be adjusted normally, and the output of the Coal Pulveriser Mills can be greatly increased.

2. The fineness of pulverized coal is coarse.

In the initial stage of Coal Pulveriser Mills operation, because the parameters are in the exploratory stage, the output of pulverized coal is low and the fineness of pulverized coal is coarse, the remaining of 0.08mm pulverized coal sieve reaches 21%, and the speed of the separator is basically full load operation, there is no adjusting space.

Due to the initial running of the equipment, in order to protect the equipment, the grinding pressure control is only about 6 MPa low, the thickness of the bed, poor grinding ability, coarse pulverized coal particles, a large number of unqualified pulverized coal into the separator at a higher wind speed, resulting in the separator can not select qualified pulverized coal.

Solution: According to the production experience of coal vertical mill system of Line 2 and the grindability of raw coal, it is reasonable to control the grinding pressure in 9-11 MPa generally. After adjustment, the grinding pressure is controlled at about 10 MPa, the bed thickness is controlled at 30-50 mm, and the air pulling and coal feeding are adjusted. The remaining of the 0.08 mm pulverized coal screen is reduced to less than 10%.

3. Low output at stage time.

The design time of the vertical mill is 30t/h (late wear), while the output of the stage is only about 25t/h.

Terms of settlement:

  • 1. Open the hot air valve as far as possible in operation, and adjust the cold air valve at the inlet of bag dust collector to control the inlet temperature not exceeding 240 degrees Celsius to reduce the resistance of hot air dust collection system.
  • 2. Reduce the inlet pressure from - 500-700 Pa to - 100-300 Pa, and reduce the ventilation resistance of the grinding system.
  • 3. Adjust the pulverizing system to pull air, adjust the frequency of the pulverizing and exhaust fan from 34 Hz to 36 Hz, increase the system to pull air, ensure that there is enough air separation, and at the same time according to the fineness of the situation to adjust the speed of the pulverizing machine to ensure that the pulverized coal fineness qualified.
  • 4. In production, it is found that there is a big difference in the output of several teams and the operation control parameters are not uniform. In view of this situation, the workshop strengthens the evaluation of the output and energy consumption of the teams and sets, and quantifies and unifies the control of the key technological parameters such as grinding pressure, bed thickness and system air pulling, so as to ensure the Coal Pulveriser Mills output. Improve obviously.