A Study And Design Of Mobile Equipments Of Drilling Wastewater Treatment By Coagulation And Centrifugalization

Drilling wastewater is characterized by complexity and variety, and drilling operation possesses characteristic of dispersedness and movability. Recently the mobile equipments used to treat scatter drilling wastewater have become hot spot of research and development because of its mobility and efficiency. But the limited space area makes the design and using condition of mobile equipments more rigorous. A study of drilling wastewater treatment by coagulation and centrifugalization was carried out for a wide range of drilling wastewater with emphasis on the type, quantity and sedimentation time of coagulant and influence of the centrifugal separating parameters on sedimentation result.The experimental results show that: (1) PAC is an ideal coagulant which can reduce CODCr colority, and suspension content of wastewater under proper operation conditions and coagulant amount; (2) if the sludge content is less then 6%, assistant coagulant is not necessary, and the residence time of wastewater in sediment cell is about 15-20 minutes; if the sludge content is about 10%, coagulant PAM should be used to accelerate the sedimentation of suspension, and the residence time of wastewater should be more then 20~25minutes; If the sludge content is over 15%, the wastewater should be separated by means of centrifuge; (3) water, sludge and oil can be separated effectively with separating factor about 2800 and separating time more than 5 seconds.A design of the mobile equipments of wastewater treatment was made using experimental results. It includes process flowsheet design, installation design, equipments and pipeline design. The merits of the present design are as follows:(1) having a compact structure of overall arrangement, i.e., small volume and occupying area;(2) being assembled properly to meet different wastewater quality and drain demand;(3) separating continuously water, oil and sludge by means of centrifuge;(4) continuous treatment to wastewater because of its high automation and easy operation;(5) usage of hydraulic and pipe mixing to simplify the equipments and save space;(6) being assembled and disassembled for transport convenience due to its constituted structure.The results of study and design provide essential information for manufacture of the equipments of wastewater treatment and are of practical significance to treating wastewater in the field.