Design of electrical control system for the hottes

  • Detail

Design of electrical control system of long fiber pulper

1 overall structure of control system (Figure 1)

the control device adopts PLC to control the frequency converter, which drives AC to feed. Through the power detection and conversion device, the power and fault of the main motor are detected to form a reliable power closed-loop control system. The controlled object is the main motor, and the main goal is to control the constant power of the main motor. The corresponding feedback control loop is designed, and the touch screen interface of man-machine dialogue and remote computer monitoring interface are designed. The current process parameters and PLC operation data are recorded remotely through the touch screen and computer. Communication with PLC is realized on touch screen and computer configuration variables. It realizes the electric touch screen to set the control value and operate, display the working state of PLC, various signal parameters collected by PLC, output the control power after program calculation and processing, and send it to the display device for monitoring. In this way, the system controls the electrical cabinet and frequency converter, and finally achieves the goal of controlling the work of the pulper. The system can operate independently and connect with other equipment in production, Realize remote control and record historical data

2 main working process realized by the control system

first, start before starting the host, close the output valve, open the return valve, start the flushing valve, finish cleaning, close the flushing valve, and start the slurry pump. Start the main motor. When the slurry concentration, pressure and temperature meet the conditions, it can feed automatically or manually to adjust the power. Set the process parameters. The feed is fast forward first, and the feed speed automatically decelerates with the reduction of power deviation. All adopt self-98.07 dynamic adjustment. Its parameters are set during debugging to prevent power overshoot, excessive feed and damage to the grinding plate. The vigorous development of automotive non-metallic materials results from the time lag between the feed and the change of power, and the inching delay technology is adopted in the feed process, That is, the inching mode of feeding at low speed for 0.5 seconds, delaying 2 seconds and waiting for the power to stabilize before feeding. Its power control effect (3) before the experiment, it is sure that the limit position is good, with high control accuracy and good stability. The direct friction between the cutter heads is avoided. After the power operates stably for a period of time, the washing of the refiner can be set as regular washing and manual washing, which are selected by the operator. In case of insufficient pressure and concentration during operation, it is necessary to withdraw the knife, open the return valve and close the pulp outlet valve at the same time, so as to prevent the unqualified pulp from being sent to the next process and affecting the product quality. In order to prevent maloperation caused by pressure and concentration fluctuations, and to prevent knife advance and retreat in case of concentration fluctuations, filter delay technology is adopted to realize instantaneous fluctuation without knife advance (retreat) and improve its stability. However, the development prospect of this technology makes people yearn for qualitative analysis. In case of concentration pressure problems, retreat the knife to the waiting position. When the pressure and concentration return to normal, continue to feed and adjust the power

for each shutdown, first open the return valve, close the slurry outlet valve, stop slurry feeding when withdrawing the knife, and stop the main motor after flushing

3 conclusion

after two years of operation, this system has proved to be stable and reliable, has produced greater economic benefits in enterprises, improved production efficiency and product quality, and realized digital management

: GE

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