Need help calculating head
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Transporting toluene at a flow rate of 30 cubic meters per hour, with a lift height of 15 meters. The liquid density is 0.87, the length of the pipeline is 300 meters, there are 15 elbows, 4 tees, and 3 valves. The inlet pressure is at atmospheric level. How should the head be calculated? What should the head be?
Use the energy conservation equation: just add up all the head losses (pipe friction losses and local losses), the pressure difference between the inlet and outlet, plus the height difference
…………At least determine the pipe diameter first; toluene is flammable and explosive, so it’s necessary to ensure a safe flow rate and minimize the generation of static electricity…………After that, consider the resistance associated with the appropriate piping components in order to finally determine the head pressure…………:)
In accordance with the \"Diameter Selection\" standard (HGT 20570.6-95) or the Guidelines for Determining Pipe Diameters in Petrochemical Process Units (SH/T 3035-2007), the pump outlet diameter was initially set at DN80. Under these conditions, the flow velocity was 1.66 m/s, the friction coefficient was 0.02198, and the pressure drop over 100 meters was 32.85 KPa (the viscosity of toluene at 20°C is 0.5866 mPa·s). The pressure loss due to straight pipes was 98.55 KPa, while the local pressure loss was 16 KPa; thus, the total pressure loss was 114.55 KPa. The static pressure drop was 128,02 KPa, and the total pressure drop across the system was 242.57 KPa. The head generated by the pump was 28.45 m
Please consider the outlet backpressure. If the back pressure is 1 atmosphere, the pump inlet is DN100 and the outlet is DN80, with a viscosity of 0.9 mm2/s, the head calculated is 37 m and the linear velocity is 1.7 m/s. The design head should be increased by a factor of 1.2 to 1.5 depending on the conditions of your system.
In addition to the conditions mentioned above, what is the maximum operating pressure that should be applied to the equipment at the pump outlet where benzene is received? Should benzene be transported to atmospheric-pressure storage tanks for storage, or to pressurized reactors or tower equipment? The operating pressure of the downstream equipment is a key parameter affecting the pump head