DESIGN AND CONSTRUCTION OF AN INDUCTION FURNACE (COOLING SYSTEM) Presented by MG THANT ZIN WIN Roll No: Ph.D-M-7 Supervisors : Dr Mi Sanda Mon Daw Khin War Oo 20th Seminar
Net Positive Suction Head Available (NPSHA) It depends upon the elevation or pressure of the suction supply friction in the suction line, attitude of the installation, and the vapor pressure of the liquid being pumped. h sp = static pressure head (absolute) applied to the fluid, m or ft h s = elevation difference from the level of fluid in the water tank to the pump inlet, m or ft If pump is below water tank, h s is positive. If pump is above water tank, h s is negative. h f = fraction loss in suction piping, m or ft h vp = vapor pressure of the liquid at the pumping temperature in meters or feet of the liquid
Net Positive Suction Head Required (NPSHR) It varies with flow, temperature and attitude have no effect. N = required motor speed, rpm Q = the water flow rate of pump, m 3 /min
Checking for Suction Performance of Cooling System of UNIDO Induction Furnace Fig – Suction line arrangement m m Pump Water tank GI Pipe PVC Pipe
Fig – Side view of water cooling tank with pumping station Known data : Capacity to be pumped 0.69 m 3 /min Required motor speed 2900 rpm Size of all pipes, valves and fittings m Foot valve Ball valve Water cooling tank Pump
Determine the Fraction Losses for GI Pipe From Moody diagram, f = where,
Determine the Fraction Losses for PVC Pipe From Moody diagram, for smooth pipe f = where,
Absolute pressure = Atmospheric pressure - gage pressure = Atmospheric pressure – water tank P abs = kPa where, 0
Fig – Vapor pressure of water
It may be suitable to use or select a centrifugal pump for cooling system of UNIDO Induction Furnace. Finally,