Horizontal Screw Centrifuge Operation Optimization On Oily Sludge Dewatering

With the development of "three wastes" treatment, horizontal screw centrifuge was widely used in oily sludge dewatering. This paper combining with the working principle and structure characteristics of horizontal screw centrifuge, studied the problems of horizontal screw centrifuge operating in oily sludge dewatering system in yan’an refinery, analyzed the main reasons that the effect of oily sludge dehydration changed poorly, and put forward the effective solutions rationally. On the basis of again, analyzed the effect of oily sludge dehydration with the oily sludge pretreatment, the speed of centrifuges, speed differential, the height of liquid ring layer, add the amount of sludge, add the amount of treating agents. And the corresponding operation parameters have been adjusted and optimized. Optimization results showed that, the water cut of oily sludge after adjusting operation parameters decreased from90%to75%, the solid content of separation liquid decreased under0.3%, the oily sludge reached the ideal treatment effect.The research results showed that:(1)the property of oily sludge related with the stability of sludge water cut that the horizontal screw centrifuge dewatered. In the operation of the actual production, through trengthening demulsification, gravity, dehydration and other measures could reduce the water cut of oily sludge and ensure its stability.(2)The speed of centrifuges, speed differential, the height of liquid ring layer of the horizontal screw centrifuge influenced the water cut of sludge and separation of liquid solid content importantly. In the process of the centrifugal dehydration of oily sludge in the refinery enterprises, should try to adopt the high speed of centrifuges and low speed differential, and the optimum height of liquid ring layer determined by experiment.(3)Add the amount of sludge and add the amount of treating agents of horizontal screw centrifuge was also the main factors affecting its dehydration effect, in the process of actual operation should screen the best combination of add the amount of sludge and add the amount of treating agents, the greatest degree meet the needs of the production and cost.(4) Daily operation process should pay attention to check the wear condition of screw propeller blades and the drum side of produced liquid overflow weir plate, ensured smooth running of horizontal screw centrifuge, guaranteed the dehydration effect.