Research On Control And Monitoring System Of Floating Material Cleaning Device

Petrochemical sewage tank is an important facility in the production process of petrochemical enterprises.Its function is to treat petrochemical sewage,accelerate the oxidation and purification of sewage,and ensure the normal circulation of sewage.However,there are some floating materials in the sewage.When the sewage passes through the pool,the floating material will remain in the pool.When the floating material accumulates to a certain extent,on the one hand,the floating material will hinder the oxidation and purification process of sewage,on the other hand,a large number of floating material may cause the blockage of the sewage tank,hindering the normal circulation process of sewage.If the floating material can not be cleaned up in time,the sewage can not be recycled normally,which will seriously affect the normal production of petrochemical enterprises.In addition,there may be potential danger in the process of floating material cleaning,so it is necessary to monitor the process of floating material cleaning to avoid accidents.Based on the analysis and research of the sewage tank in the polypropylene production line of Tianjin Petrochemical Enterprise and the structure characteristics and the process of the floating material cleaning of the device,the measuring method of floating material thickness,the detection method of objects in the sewage tank and the evaluation method of cleaning quality of floating material are put forward in this paper.The control system of floating material cleaning device based on PLC and the safety monitoring and early warning system based on visual inspection technology are designed.The main research achievements of this paper include:(1)Making a deep research on the actual working conditions of petrochemical sewage tank and the structural characteristics of the flotation cleaning device,identified the potential dangerous types in the site of petrochemical sewage tank.Through the study of the theory and technology of risk monitoring,combined with the specific situation,the detection technology used in this paper is determined.(2)Based on visual inspection technology,a fringe marking method for measuring the thickness of floating material is proposed.The method uses monocular vision to measure the thickness of floating material.It has the advantages of simple measurement system and fast measurement speed.By measuring the number of marked fringes,the method avoids the direct measurement of distance and makes the measuring system unaffected by the change of measuring angle and liquid level,so that the measuring system has strong applicability and robustness.(3)Based on the visual inspection technology,using depth learning and BP neural network algorithm theory,the feature classification method of objects detection and the floating material residual rate method of floating material cleaning quality evaluation are proposed.The algorithm of objects detection and the quality evaluation algorithm of floating material cleaning are compiled by using image processing software HALCON.The two algorithms are validated on the experimental platform of the monitoring system.The results show that the objects detection algorithm can accurately detect objects with different positions,sizes and types;the floating material cleaning quality evaluation algorithm can accurately make a correct judgment on whether the floating material cleaning is clean or not.(4)The control and monitoring system of the sewage flotation cleaning device is designed,including the control subsystem of the flotation cleaning device based on PLC,the liquid level adjustment subsystem,the danger early warning subsystem and the visual monitoring subsystem.