Porous Cavitation Plate Hydraulic Devices And Strenthening Effect Of Experimental Study

Hydrodynamic cavitation is a new technique in wastewater treatment schemes. Comparing with acoustic cavitation, hydrodynamic cavitation is superior obviously with simple structure, smaller energy consumption, operation convenience, lower maintenance and enlarging easily scale-up. However, the technique is still stage of basic theoretical research and experiment, there are still many problems to be researched and solved either theoretically or experimentally.Hydrodynamic cavitation is a new method of engrgy use due to its ability to enhance chemical processes.Cavitation bubbles while exercising and collapsing in the liquid can give out partial heat high pressure, pound at wave ,high speed to shoot and flow an extreme physical condition etc. This can make out the chemical reaction of the hard realization that in the general terms cannot carry out. It destroys the molecular bond of water and forms free radicals. The strong oxidbillity of free radicals are responsible for enhancing chemical processes.In order to study the set-up and system of hydrodynamic cavitation, research the mechanism and effect of hydrodynamic cavitation enhancement, find the basic rule which affected it. The work has been carried out as following.(1)An effective equipment of hydrodynamic cavitation is built. In the hydrodynamic close cycle set-up test, the hydrodynamic characteristic of different multiple hole orifice plates and the set-up and system of hydrodynamic cavitation have been researched in this thesis . Through the hydrodynamic characteristic experimental study of multiple hole orifice plates showed, Increasing inlet pressure of the multiple hole orifice plates can increase flow of the multiple hole orifice plates, thus rise the average velocity of flow in holes and decrease cavitation number. In maximum recovered pressure position of the certain multiple hole orifice plates downstream experiment, measure the multiple hole orifice plates downstream recovered pressure , the length L =17.5dn (dn is the pipe diameter).(2) The methylene blue and spectrophotometer method can the free radicals generated successfully. This is an effective way to measuring the free radicals quantitatively in caviation, moreover it is easy to fulfill.(3) The intensity of caviation increases with reduction in the caviation number.(4) Exist the best geometry parameters in the system of the different plates (for example: orifice number,orifice diameter,area ratio,thickness ) and the best operation parameters ( inlet pressure,recovered pressure,flux ), through controlling hole geometry parameters of plates and operate parameters , can produce the better work condition, thus making it the degradation velocity constant is higher.