A batch centrifugal filter having a bowl diameter of 750 mm and a bowl height of 450 mm is used to filter a suspension having the following properties:

Liquid, water                                                                   Final thickness of cake, 150 mm

Temperature, 25°C                                                         Speed of centrifuge, 2,000 r/min        

Concentration of solid in feed. 60 g/L                         Specific cake resistance, 9.5 x 10¹⁰ ft/lb

Porosity of cake, 0.435                                                   Filter medium resistance, 2.6 x 10¹⁰ ft^-1

Density of dry solid in cake, 2,000 kg/m³  

The final cake is washed with water under such conditions that the radius of the inner surface of the liquid is 200 mm. Assuming that the rate of flow of wash water equals the final rate of flow of filtrate, what is the rate of washing in cubic meters per hour?