Print page

Email page

Suitable reactor capacity

Q: We have installed a cylindrical dish-end type of SS reactor with a capacity of 1,500 L, diameter of 1,200 mm; height of 1,350 mm; depth of 50 mm; total height of 1,650 mm; and the required rpm at the agitator end is 500-600 rpm. Process details are: paste type liquid (free flowing); specific gravity around 1.0; viscosity of liquid is 350-600 cSt.; agitator is vertical with four, 45-degree vertical turbine-type impellers. Suggest the suitable capacity of torque with its rpm selection to have the desired rpm at the end of the impeller withstanding the torque generated by the liquid during the mixing. Can we operate the same system with gear motor?

A: For a vessel with a 1,200-mm diameter, 1,350-mm straight side, 1,500-L capacity with a liquid viscosity 600 cp and specific gravity 1.0, and a 45-degree, four-blade, pitched-blade turbine operating at 600 rpm, the impeller should be 250 mm in diameter to create moderate mixing intensity with either four wall baffles in the tank or an angle-offset mounting to prevent swirling. The 250-mm diameter impeller needs a 2.0-kW motor and, therefore, a 32 Newton-meter torque drive.