The Design And Usage Of Jalousie Cathode Structure In NF₃ Electro Bath

This paper describes the process of nitrogen trifluoride bulk production by electrolysing generation method and the problems during electrolyzing, such as big disturbance of voltage and temperature, significant drop of acidity and nitrogen concentration which will overstep the accepting range, low average NF3 output and difficulty of improving electric bath current efficiency. By analysis the structure of the electric bath equipment, the paper presents the idea to replace to old flat board cathode with the jalousie cathode, aiming at improving the electrolyte flow cycle near cathode, enhancing the heat and mass transition and solving the mentioned problems.Based on the jalousie cathode design requirements, the design is carried out around several aspects: material choosing, structure design, parameters calculation, cross board amelioration and strengthen bar design. By contrasting, analysis and calculation, the output is: Q235B as cathode material, lamina horizontal arrangement, lamina extroversion angle 30 degree, 10 laminas on each side and the size is 6×30×1680mm, laminas space is 29mm, 2 strengthen bars on each side and trepanning on the across board. At last, a stress analysis and an intension proofread are carried out for the cathode connection. In order to test the practicability and validity of the jalousie cathode, a 3000A electrical bath test is arranged under the same process and electrolyte recipe.The result of the above experiment proves that for electric bath equipments, the replacement of the flat board cathode with the jalousie cathode can reduce the rise of the electrolyzing voltage from 30% to 10%, avoid drop of acidity and nitrogen concentration– acidity around 36~37% and nitrogen around 3.2~3.5%, reduce the rise of temperature from 32% to 12%, increase the average NF3 output from 56% to 58% with a highest output about 59%. The ultimate current density of the cathode can be raised and the probability of concentration polarization can be decreased. The electrolyzing current efficiency rises by 12%.