Structure And Working Principle of High Temperature Melt Pump

High temperature melt pump is an indispensable equipment for conveying, pressurizing and metering high temperature and high viscosity polymer melt. Compared with other types of pumps, high temperature melt pump has compact structure, reliable operation, low energy consumption, high volumetric efficiency, small shearing effect on melt, stable flow rate under high viscosity and high pressure, and no outlet pressure fluctuation. The unique advantages of this pump and its key role in the process make it play an irreplaceable role in polyester production.

The melt gear pump consists of a pump housing, front and rear side covers, a gear shaft, a sliding bearing and a shaft seal. The melt gear pump is a positive displacement pump. When working, it relies on the change in working volume caused by the mutual meshing of the master and driven gears to transport the melt. The working volume is composed of the pump body, the tooth grooves of the gears and the bearings with the function of side plates. When the gears rotate, the melt enters the tooth grooves of the two gears in the suction chamber. As the gears rotate, the melt is brought into the discharge chamber from both sides. The re-engagement of the gears squeezes the melt in the tooth grooves out of the discharge chamber and presses it into the outlet pipe. As long as the pump shaft rotates, the gears press the melt to the outlet side, so the pump outlet can reach a very high pressure, and the flow rate has nothing to do with the discharge pressure.

The gears of high-viscosity gear pumps are commonly straight, helical, herringbone, and spiral, and the tooth profiles are mainly involute and arc types. Usually, small gear pumps mostly use involute spur gears, high-temperature gear pumps often use displacement gears, and melt pumps that convey high-viscosity, high-pressure polymer melts mostly use involute helical gears. The gears and shafts are made into one piece, and their rigidity and reliability are higher than those of gear pumps in which the gears and shafts are made separately. The gears of foreign low-pressure gear pumps often use a square structure, that is, the gear tooth width is equal to the tooth top circle diameter. The gear tooth width of the high-viscosity gear pump used in high-pressure situations is smaller than its tooth top circle diameter. This is to reduce the radial pressure area of the gear and reduce the load on the gear and bearing.

NANJING HAISI is professional manufacturer of plastic extruder, we supply Twin Screw Extruder, Single Screw Extruder, Plastic Recycling Extruder, Two Stage Extruder, Lab Scale Extruder, Mixing and Feeding Machine, Cooling and Pelletizing Machine, Crushing Machine and so on.