Before buying a lobe pump, you need to know the flow needs and choose the pump from the manufacturer. Manufacturer provides the model of pump data like below picture
Lobe Pump Selection table
Calculate the flow of lobe pump
Per revolution flow means lobe pump rotation in one minute, flow in one minute, take TUL/ TUR-20 as an example, the flow per revolution is 0.12L for a minute. If the rotary lobe pump transfer very thick media, viscosity is 10,000cps, the motor should be worked at low speed, 200 rpm.
The calculation of flow in one hour =per revolution 0.12L x 200 rpm x 60 minutes= 1440L/h (1.4m3/h)
Of course, the motor speed rpm is different during transfer different media.
The motor speed should work at a suitable speed, the higher viscosity, the motor should work lower speed. If work too fast, the pump will shake, make a big noise and even break.
Media viscosity less than 500cps should choose the model of at least double-flow because Low viscosity fluids can“slip” at high output pressures, reducing efficiency, not recommend to transfer low viscosity fluids
Select from the table using the viscosity, the maximum recommended speed for lobe pump