Flow Numerical Simulation And Structure Optimization Of Biomass Filter

Filtration technique is the most critical process of oily sewage treatment, and thefiltration efficiency relates directly to the quality of filtrate. At present, various kinds of filterswith different filtering materials of high performance have been widely used, which are lackof suitable water distributor. The Preliminary test shows that, the utilization of filteringmaterial appears the inverted trapezoidal shape after direct filtration without water distributor.That means the central zone is penetrated after fully utilized with a certain degree of materialconsumption, however, the lower part of circumjacent zone is underutilized which has to bebackwashed or replaced because of the penetration of the central zone. The phenomenonresults in the decrease of filter cycle and the waste of filering material, which all leads to thereduction of filtration efficiency. Hence, it is imperative to research and design the waterdistributor which is appropriate for oily sewage filter.The article takes numerical simulation as main research method, with the supplementaryof experimental test to focus on the study of orifice water distribution plate. Based on theoriginal “annular velocity evaluation method”, adjusting and optimizing the structure of theorifice distribution to achieve the best distribution. The study shows that, circular equidistantorifice distribution with diffenert diameters is beneficial to better water distribution. With theincrease of the thickness of orifice plate, the annular velocities of inner rings raise, whilethose of outer rings decrese. With the increase of the distance between orifice plate and inlet,the annular velocities of inner rings raise, and those of middle rings increase first thendecrease, while those of outer rings change conversely sharing the same turning point of thefurther one. Moreover, the optimized orifice plate is proven to be with good operationalflexibility of velocity. According to the above rules, it is easier to design and optimize theorifice plate suitable for the industrial filter, which shows the orifice diameter distributionalong the radial direction takes the “M” shape. Therefore, the orifice plate can help evenlydistribute the incoming flow and decrease the longitudinal space as well.The potential rule between orifice diameters and annular vilocities is found in theprocess of structure optimization which has great value to increase the adjustment efficiency by predicing more suitable orifice diameters. It helps to put forward the adjustment strategyfor orifice diameters. Then the dynamic mesh technique with UDF based on the strategyachieves the automatic adjustment of orifice diameters, which makes the most of numericalsimulation and increase the design efficiency significantly.The ultimate purpose of the study is distributing the incoming flow uniformly to makethe full use of filtering material to increase the adsorption of oil removal and filteringefficiency. Hence, comping the UDF of adsoption based on the adsorption theory forexploratory study. The study shows that the optimized orifice plate can help avoid invertedtrapezoidal utilization of filtering material, which gives a concrete proof of the significance ofoptimized orifice plate leading to better filtering material utilization as well as the filteringefficiency.