nbsp nbsp nbsp nbsp Several factors that restrict the strength of aerated concrete; nbsp nbsp nbsp The motor system control of Raymond mill is concentrated in the control cabinet, all levels are interlocked with each other, and the automatic feeding is controlled by the change of main machine current to control its feeding amount. The start-up of each machine should be carried out according to the operation procedure and specifications.
In this control cabinet, except for the main machine, analyzer and feeder, the rest motors are general AC asynchronous motors.
1. The start-up control of the main machine and fan of Raymond mill In this control system, for motors with capacity greater than 30kW, reduced-pressure start is used, and direct start is used for those less than 30kW. In the system, the crusher, the main machine fan adopts Y-Delta start.
2. Control and automatic feeding of vibrating feeder The structural principle of electromagnetic vibrating feeder, the electric vibrator is a double-mass point directional forced vibration system, consisting of a material trough connected to the fork armature. It is freely hung at the lower end of the silo with a certain swing clearance, and must not be jammed or collide with other objects to avoid noise during work.
(1) After the vibrator is installed, loosen the screws acting on the positioning fork (upper and lower three), tighten them with nuts after loosening, open the rear cover of the vibrator, check that the gap between the core and the armature should be within 1.8~2.1 mm, and both should be clean. All screws should be tightened, and finally install and fix the cover.
(2) No-load test under power-on, gradually increase the amplitude potentiometer R1 on the electrical control box from small to large, its amplitude should be within 1.8~2 mm, and the current is 1.2A. After continuous operation for several hours, check whether the amplitude and current are stable. After normal operation, open the silo gate to feed, observe whether the feeding amount and current are stable, allowing the amplitude to decrease by 0.5 mm. If the amplitude and current reach the rated value but still cannot meet the feeding requirement, tilt the vibrator suspension by 20° to meet the feeding requirement.
(3) Automatic feeding adjustment, automatic feeding is realized through the change of main current. When the fan operates normally, if the main motor current exceeds the rated current, the feeding will stop. When the current drops, it will automatically feed again. This is mainly achieved by the action of the current relay to disconnect and connect the controllable voltage, thus realizing feeding and stopping.
The DL-12/6 type overcurrent relay has 2 coils inside. When connected in series, the operating current can be adjusted from 1.5 to 3A. When connected in parallel, the operating current can be adjusted from 3 to 6A. When the mill operates normally, the current transformer changes the current locked on the current relay will not exceed 3A. Therefore, the coil is connected in series.
(4) When starting automatic feeding, switch the main command switch on the control cabinet door to the automatic position. Gradually increase the potentiometer R1 knob on the control box, so that its current reaches the rated value and stabilizes. At the same time, adjust the slider of the current relay according to the rated current of the main machine to change the operating current of the relay. When it rises, make the normally closed contact open, and immediately close when the current slightly drops, so that the mill always maintains the optimal working state, avoiding idling or overload, ensuring the efficiency of powder production of the main machine.
(5) The analyzer uses JZT type speed-regulating motor transmission, which is controlled by the electromagnetic slip controller (ZLK-1 type) button on the control cabinet. Press the start button first to run the squirrel cage motor part, then close the slip power switch, adjust the speed knob to make the analyzer reach the required speed and fineness (particle size) to match, thereby controlling the particle size of the powder.
Comparison of new ultrafine Raymond mill and traditional Raymond mill
Raymond mill is also called Raymond machine, mill, Lei mill, English full name: Raymond mill, a widely used grinding equipment.
Raymond mill is a widely used grinding equipment in mines, cement plants, chemical plants, and is one of the important equipment for deep processing of non-metallic minerals. Due to its stable performance, strong adaptability, and high cost-performance ratio, since its introduction to our country more than 20 years ago, it has been widely applied in the processing of non-metallic minerals.