Study Of Swirl Choking Cavitation Technology For Disintegrating Sludge

The construction cost of sl udge treatment and disposal is very expensive,it is the percentage of 50-60 for the total construction cost.How to realize sludge reduction,stabilization and resources,has attracted more and m ore attention of sc holars at home and ab road.The hydrodynamic cavitation will produce many tiny bubbles in the liquid,the bubbles will produce strong shock wave and micro jet at the moment of instant collapse,and accom panied by extreme conditions of high temperature and pressure.There is floc and m icrobial cell containing soluble organics and water.If the sl udge can be effectively disintegrated by hydrodynamic cavitation,the volume of the sludge will be greatly reduced,and the efficiency of wast ewater treatment can be great ly improved.Based the theory of choki ng cavitation and rotating jet,a new type of hydrodynamic cavitator named swirl choking cavitator have been invented,and it was analysed of fractal characteristic for cavitation noise and experimental study of disintegrating sludge.The results of fract al analysis for cavitation effect shown that the box dimension values of cavitation noise signal for swirl choki ng cavitator can be us ed to estimi mated the intensity of cavitation and cavitation effec.When the swirl c hoking cavitation noise signal box dimension values D<1.27,cavitation effect is best.box dimension values 1.27?D?1.33,cavitation effect is good.box dimension values D>1.33,cavitation effect is poor.The results of field experim ental study on disint egrating sludge shown that swirl choking cavitator can disintegrat e sludge efficiently by breaking the sludge floc and m icrobial cell wall,making their internal water and organic released,which results in increasing of SCOD,turbidity increases and MLSS redu ced.The soluble chem ical oxygen demand SCOD in sludge m ixed liquor turbi dity,suspended solids concentration of TU increased,MLSS reduced.The sludge has a sm all change for pH,after disintegra ting,the pH is influenced slightly by the technology,which shows that choking cavitation is very useful in solving engineering problems.When the cycl one core length 3/ 4 lead,the back pressure is 89 KPa,the effect of disi ntegrating sludge is best,and cycle number N of 20,D R reaches 661.57%.For different swirl core length of swirl choking cavit ator,there are op timal back pressure range,which under the same cyclone core length,th e effect of disintegrating sludge is better.