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Research On Non-contacting Testing Device Of Individual Anode Current Of Alumina Reduction Cell

Posted on:2015-07-25Degree:MasterType:Thesis
Country:ChinaCandidate:Y DongFull Text:PDF
GTID:2181330434453935Subject:Power Engineering
Abstract/Summary:PDF Full Text Request
ABSTRACT:It is very important to realize the individual anode current real time monitoring and on-line control in aluminum reduction cell, because aluminum reduction cell is a complex multivariable system. However, the most common method of measuring individual anode current is by using a two point probe, connected to a voltmeter, to measure the voltage drop down a known length of the anode rod. Which is labor-intensive, time-consuming and low precision cannot realize the online detection of the individual anode current. Compared with the common method, the non-contacting measurement of the individual anode current has characteristics of high precision, good operation stability and easy online monitoring.Based on the principle of electromagnetic field in aluminum reduction cell, a non-contacting measurement of individual anode current was put forward, which was established by detecting magnetic field near each anode rod to achieve the accurate individual anode current. Therefore, a new testing device of the individual anode current was designed. Main work was done as follows:(1) Taking the principle of electromagnetic field in aluminum reduction cell and previous works as the foundation, the coupling relationship between magnetic field and electric field, which can be represented as I=Bx/C, was established. Furthermore, based on this expression, the mathematic model of achieving the individual anode current by detecting magnetic field was established and a novel non-contacting measurement method was put forward.(2) The verification of the non-contacting measurement method has been carried on300kA cell with five risers. The results show that the relative errors of the combination mode of three sensors are reduced effectively and distribute between0.35%and0.90%. The relative errors of the combination mode of the13mm spacing between sensor1and sensor2and the5mm spacing between sensor land sensor4are reduced significantly and evaluated to be within0.3%.(3) The error distribution of the individual anode current was analyzed and the measurement method was optimized on aluminum reduction cell with various current risers. The relative errors of the anode current in300kA cell were within0.25%, but the relative errors of the anode current in400kA and200kA cells were0.8%and3%respectively. Therefore, the non-contact measurement is applicable to online monitoring of individual anode current with different current risers and structures in aluminum reduction cell.(4) The industrial experiment has been carried on300kA cell with five risers and the testing result was compared with one of the traditional measurement method. Compared with traditional measurement method which has the trouble of bad contact, bad operation stability and frequent dismantle, the non-contacting measurement method not only has no these troubles, but also has the characteristics of high sensitivity.(5) The software of predicting and quenching anode effect has been developed based on the anode current measurement device, which can predict anode effect successfully.
Keywords/Search Tags:aluminum reduction cell, anode current, non-contacting measurement, magnetic field, anode effect
PDF Full Text Request
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