Design And Realization Of The Control System Of Horizontal Screw-conveyor Centrifuge

The horizontal screw-conveyor centrifuge is the key equipment to actualize the separation of solids and liquor. Rotary drum's rotary speed and the rotary speed diference between rotary drum and screw-conveyor are very important variable parameters of the horizontal screw-conveyor centrifuge when it is being operated. The effect and output of separation are determined by the rotary speed and the rotary speed diference between drum and screw-conveyor. High efficient dehydration of centrifuge just can be realized by perfect automatic control system. Since the requests of the centrifuge equipment are becoming higher and higher, centrifuge have been renewing continuously. Reliability, easy operability, can-be-surveilled, easy maintenance have been the basic requirement. The relay control system is undependable, and its maintenance and surveillance are hard. It had not adapt to the current requirement any more. PLC has become the main domestic and international control method as developing of electronics technique, computer technique and control technique.The control system which is meet to the requirements of speed-adjusting has been designed according to the characteristic of horizontal screw-conveyor centrifuge. After the principle and key technique of centrifuge were analyzed thoroughly, mud pump was decided to be drove by electromagnetic timing electromotor, and rotary drum and screw-conveyor to be drove by transducer. Stepless speed-adjusting can be actualized. Temperature automatic controller was set on the back-up bearing to guarantee long-term reliability of centrifuge.Combining with the characteristic and requirement of the equipment, PLC control system with facility and reliability was finished. System functions were realized by software. During the progress of contol tank making and locale debugging, going into technique of anti-jamming, some measures, including hardware and software, were took to protect the control system from jam.In this task, for the sake of practicability, we mostly payed attention to the feasibility of the design project. Although just one certain centrifuge was considered in this thesis, its ideas and methods can offer references for the design of horizontal screw-conveyor centrifuge of other types.