Study On The Design Of Cylindrical Solid-Liquid Separating Device Used In Waste Drilling Liquid Treatment

Nowadays, environment pollution caused by the high speed development of petroleumindustry to which has been paid great attention, especially the waste materials produced in theprocess of natural gas exploitation, such as the waste drilling fluid. In this theses, basing onthe sufficient analysis of the Shengli oilfield’s emulsion breaking and flocculationtechnologies, a solid-liquid separation device taking the cylinder screening machine as themain body is designed. Using this device, innocent treatment of the waste drilling fluid canbe fulfilled.On the bases of non-modification of the existing drilling fluid’s circulation treatmentstructure, we design a self-contained spiral conveyor to collect the waste fluid automatically.After the demulsifying agent added by the dispensing device, the waste fluid is conveyed tothe cylinder screening machine and to be separated into solid phase and fluid phase. Lastly, aproper flocculating agent is added into the fluid phase to make it become floccule and to betreated by the pressure filter.The main achievements by the preliminary research are shown as below.（1）Having analyzed the waste drilling fluid’s resource, water quality, present treatmentmethod etc, we implemented an experiment to obtain perfect demulsification and flocculationtechnologies, and chose the optimum coagulating agents and organic macromoleculeflocculants. By doing this, we obtained the main factors that influence on the demulsificationand flocculation results.（2）According to the field production data, we optimized the structure parameters of thedrum-type device that can separate the solids from water. At present, we have completed thestress-strain calculation of the drum inner wall, and have given some key parameters such asdrum diameter, effective volume, driving shaft, revolving speed, separation coefficient,opening dimension etc; the next step is piece production soon. Once we can separate thesolids from water effectively, the material cost of waste drilling fluid treatment will bereduced greatly.（3）The main design work of the belt filter press (system using with the drum-typescreen) has been completed, such as scheme planning, structure design, and filtration theory analysis; meanwhile, the press roll, filter frame, and belt offset have been designed.