4 ROTARY PUMPRotary pumps are used in a wide range of applications -- liquids, slurries, and pastes. And because rotary pumps displace a known quantity of liquid with each revolution of the pump shaft, they are a popular choice for metering applications. They can accommodate high viscosity liquids, high pressures, and high capacities. Rotary pumps are available in a number of different pumping principles, each with its own unique set of advantages and disadvantages.
5 ROTARYPUMPCLASIFICATION Rotary Pump devided into 2Chapter:1. single rotor-vane-piston-screw-peristaltik-progressing cavity2. multiple rotor-gear-lobe-circumferential piston
6 VANE PUMPThe vanes - blades, buckets, rollers, or slippers - work with a cam to draw fluid into and force it out of the pump chamber. The vanes may be in either the rotor or stator. The vane-in rotor pumps may be made with constant or variable displacement pumping elements. Figure 4 shows a sliding vane pump.
8 SCREW PUMPScrew pumps carry fluid in the spaces between the screw threads. The fluid is displaced axially as the screws mesh.Single screw pumps are commonly called progressive cavity pumps. They have a rotor with external threads and a stator with internal threads. The rotor threads are eccentric to the axis of rotation.Multiple screw pumps have multiple external screw threads. These pumps may be timed or untimed.
10 GEAR PUMPInternal Gear. Internal gear pumps carry fluid between the gear teeth from the inlet to outlet ports. The outer gear (rotor) drives the inner or idler gear on a stationary pin. The gears create voids as they come out of mesh and liquid flows into the cavities. As the gears come back into mesh, the volume is reduced and the liquid is forced out of the discharge port. The crescent prevents liquid from flowing backwards from the outlet to the inlet port.External Gear. External gear pumps also use gears which come in and out of mesh. As the teeth come out of mesh, liquid flows into the pump and is carried between the teeth and the casing to the discharge side of the pump. The teeth come back into mesh and the liquid is forced out the discharge port. External gear pumps rotate two identical gears against each other. Both gears are on a shaft with bearings on either side of the gears.
12 GEAR PUMPGear pump is the most commonly use in daily life. This pump doesn’t have valve and the seal depend on the small distance between gear wheels and the case. This pump flow fluid in the high pressure until 35 MN/m2.
13 LOBEFluid is carried between the rotor teeth and the pumping chamber. The rotor surfaces create continuous sealing. Both gears are driven and are synchronized by timing gears. Rotors include bi-wing, tri-lobe, and multi-lobe configurations.
17 Liquid containmentHigh-Viscosity Liquids. Internal gear pumps are often a good choice.Sanitary Liquids. Sanitary lobe pumps work well for most food, beverage, pharmaceutical, and biotechnology applications.Solids. Pump selection depends on the particular application. For food-type applications containing solids, begin searching sanitary lobe pumps. For slurries and other industrial-type solids, start with internal gear pumps.Corrosive Liquids. Proper selection of the right materials of construction will have the greatest impact on pump performance. Composite external gear and stainless steel internal gear pumps are good starting points. Check out Pump School's page on handling abrasive and corrosive liquids.Abrasive Liquids. A number of factors can combine to minimize the effects of abrasion. Begin with internal gear pumps manufactured with hardened steel parts. Toxic, Hazardous, or Hard-To-Seal Liquids. Preventing leaks is critical for handling these fluids. Magnetically-driven or mechanically sealed internal or external gear pumps offer a good starting point.Extreme Temperature Conditions. Internal gear pumps with jacketing features offer excellent temperature control. Learn more about handling high-temperature liquids in Pump School's "Tough Application" section.