2.2. Apparatus setup
Schematic representation of experimental setup of hydrodynamic cavitation system and the dimensions of the applied orifice plate are shown in Fig. 2. The system consists of a feed vessel tank with 1.25 L capacity, a vortex pump (25WB-65, Shanghai Hongya Machine Pump Making Co., LTD, 3 kW, 2900 rmp, 0.3 m3/h), and valves. The discharge pipe of pump is connected to the suction side on the bottom of the tank and bifurcated into main and bypass lines. The main line and the bypass line discharge the material back into the tank. The main line has the facility to incorporate an orifice plate located over the pressure gauge to generate cavitation of different intensities. The bypass line has a throttling valve for adjusting pressure and flow rate into the main line. The water passes through the orifice plate, causing the central pressure at the cavity falls below the vapor pressure of the water and generating a number of cavities. The pressure gauges are provided and recorded both in inlet line and downstream of the orifice plate. During the experiment, control valve (in bypass line) was left open until the pump reaches its maximum speed, and thus the desired pressure and flow rate were obtained in the mainline.