The Development And Supplyment Of Alumina Sedimentation Tank Mud-layer Interface Detect

Liquid-solid interface, on-line auto-detection has been a difficult point in the industrial field. In particular, the high level of the mud layer is required to detect on the alumina sedimentation tank.So far,there are no the particular mature products in the method.Because the alumina digestional material have the characteric of the proportion different and radioactive trace elements in bauxite stone, in the foreign,it has been introduced infra-red method, ultrasonic method and radiation method to measure mud-layer height, turbidity and other parameters in the alumina settlement tank.Then the operator may adjust to the product-system.so it can ensure that the settlement tank overflow, underflow indicators to compliance.At the same time,the blowing method has been introduced to detect a high degree of mud layer of alumina settling tank in our country. However, the devices were forced to stop run in the end by anyway.The reason was mainly due to the high temperature, high alkali and easy scarring and other technological features in the alumina dissolution process,which led to device is not long-term use.In order to overcome the impact of alumina process, Generly to from top to bottom, the material density gradually increases in the alumina deposition tank, we decided to use buoyancy method and build mathematical models.After the computer analysises and treats the data,so that we can get the required height of mud layers.We catched the opportunities of the four sedimentation tanks trough subsidence transformation. This paper introduces the mechanism of subsidence trough subsidence materials analysis and research, by the use of buoyancy principle,we produce the latest sludge interface detector of alumina settling tank and detect sedimentation tank sludge layer height. At the same time, because the system is the four settling tank mud layer interfaces,we used the latest technology, field bus PROFIBUS-DP networking to meet industry requirements. Of course.it can connect with the whole plant Ethernet.Paper describes the work of this study from the subject, process mechanism of research, program selection, hardware design, software design. installation and commissioning. The entire network system adopts to the three-tier network architecture.On-site from the station with S7-200 PLC, the system achieve buoyancy test-value through Siemens SIMAWARE MS weighing module, then it may access to PROFIBUS-DP bus through communication module EM277. Master station with S7-300 may finish the system-wide data processing and automatic control. Host computer uses MCGS configuration software. through the MPI card (CP5611) and the next crew S7-300 communication, then to access to DP network, the eventual realization of good man-machine interface detection and controlment.The using of the site through the device more than three months, we have analysised the accuracy and reliability of the equipment. it solved basically the impact of the alumina deposition process high temperature, high alkali, easy to scarring for testing equipment. Therefore, the device can be extended to the entire aluminum industry and other similar industries.