Research On Positioning Method Of Electrode Length Measuring Device For Submerged Arc Furnace

The self-baking electrode is the core component in the smelting process of the ore-heating furnace.Controlling the degree of electrode sintering,graphite electrode length and depth into the furnace is the core operation to improve production efficiency,reduce energy consumption and avoid production accidents.At present,most of the electrode length measurement in calcium carbide plant is done manually,which can’t realize real-time measurement.The electrode length measurement system of ore-heating furnace uses the time difference of acoustic wave reflected at the interface of different media to measure the electrode length.By this method,the distance between the different media interfaces and the electrode length measurement device can be obtained.In order to obtain the absolute position（relative to the earth）of the different media interfaces of the mineral-heating furnace,the position of the electrode length measurement device needs to be determined,so the positioning system of the electrode length measurement device is designed according to the requirements.In this paper,the position of each unit of the electrode length measurement device is measured and a composite coordinate system is established,and the positioning of the electrode length measurement device is realized by the coordinates of each unit on the composite coordinate system.Firstly,the first absolute coordinate system is established by the earth,and the coordinates of the electrode barrel cover Z₁ are measured by the ultrasonic distance measurement module on this coordinate system;secondly,the second relative coordinate system is established by the position of the electrode barrel cover,and the coordinates of the electrode length measuring device Z₂ are determined by the cooperation of the focusing magnetic peg array and the focusing sensor array on this coordinate system;finally,the third relative coordinate system is established by the position of the electrode length measuring device,and the coordinates of the electrode length measuring device Z₂ are determined by the cooperation of the focusing magnetic peg array and the focusing sensor array on this coordinate system.According to these three coordinate systems,a composite coordinate system is established to achieve the final positioning of the electrode length measurement unit.The overall fullness error of the electrode length measurement system is obtained from the error analysis of the measurement results of each unit,which reaches the accuracy level of 0.3 for detection and display instruments for industrial process measurement and control.