Structure Optimization And Thermoelectric Field Of Graphitization Furnace

At present,there are two main types of furnaces commonly used in graphitization process,acheson graphitization furnace and internal thermal series graphitization furnace.But both of them have the disadvantages of large heat loss,long cooling time and long production cycle.Continuous graphitization furnace came into being.In the continuous production process,it can make full use of electrical and thermal energy to ensure uniform product performance.However,because this technology started late and is less mature than the previous two graphitization technologies,it has few industrial applications,so it is necessary to increase research on this technology.This paper aims to optimize the structure of the graphitization furnace by studying the specific effects of electrode parameters and electrode structure arrangement on the temperature distribution and electric field distribution in the electric furnace.The main work contents were as follows:(1)For the graphitization furnace in production,the mathematical model of thermoelectric field coupling during the graphitization process was established,and the numerical solution was performed using ANSYS WORKBENCH software.(2)The specific effects of electrode parameters,such as electrode diameter,electrode spacing and electrode penetration length,on the temperature distribution and electric field distribution in the electric furnace were studied.(3)Based on the orthogonal test method of the L9(3^4)orthogonal table,9 orthogonal schemes were determined for numerical calculation.Through the range analysis,the importance of each factor of the electrode parameters to the indicators of the graphitization process of the electric furnace was clarified degree,the optimal level combination was sought.(4)Three electrode layouts were adopted,that was,the electrodes were distributed around the top of the furnace body,the upper and lower ends of the furnace body,and the left and right sides of the furnace body.The electrode layout on the heat and electric field of the graphitization furnace was studied Specific impact.After research,the following conclusions were drawn:(1)The heating area of the electric furnace was mainly concentrated between the two electrodes;the electric field strength and current distribution trend were the same,and the high values of the two were distributed near the electrode;the high temperature area was mainly distributed in the middle and lower part between the two electrodes,and the temperature can reach 2400 ?.(2)The reduction of the electrode spacing and the increase of the electrode diameter both lead to the expansion of the high-temperature area and the increase of the peak temperature,and the reduction of the electrode spacing by 0.1m and the increase of the temperature peak by 130?150?;when the electrode diameter increases by 0.1m,the peak temperature increases 120?180?;the length of the electrode deep into the material increases,which causes the expansion of the high-temperature area and the decrease of the peak temperature.For every 0.1m increase of the electrode deep into the material,the peak temperature increases by about 74?;the higher the voltage,the higher the temperature in the furnace,but the temperature rise decreases from 760°C to 300°C,and as the voltage increases,the graphitized area in the furnace increases.(3)The first orthogonal method was the best solution,and the importance of the electrode parameters was that the electrode penetrates into the material length>electrode spacing>electrode diameter.(4)Under the same conditions,when the electrode was in the first arrangement,the furnace body temperature and electric field strength were high.In the second and third arrangement,the furnace body temperature and electric field strength were both low,but the first the furnace body temperature uniformity of this arrangement was worse than the latter two arrangements.In order to improve the temperature uniformity of the furnace body,a fourth electrode arrangement was proposed,that was,the positive electrode of the electrode was arranged in the center of the furnace body,and the negative electrode was arranged in an arc plate around the positive electrode.(5)Based on the fourth electrode arrangement,a new furnace type of continuous graphitization furnace combining two production processes of petroleum coke calcination and graphitization was proposed.In order to further determine whether the new furnace type improves the energy utilization rate,the heat loss and production cost of the lining of the new furnace type were calculated.The results showed that when the graphitization area of the new furnace type with a voltage of 28 V and the production furnace type with a voltage of 40 V.The graphitized area was roughly the same,and energy consumption was reduced by 43.75%.Because the negative electrodes in the new furnace were arranged along the ring,the graphite electrode consumption was intensified,and the electrode cost was relatively high,but it can be recovered in a short time.This method was worthy of research and promotion.