POLY
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Discharge gear pump

POLY POLY high-pressure gear pump for the discharge of medium to high viscose media from the reactor. The extra large inlet opening guarantees an even flow of product to the gearwheels even under vacuum or extremely low NPSH conditions. Offered with either a round inlet port, by means of which the suction flange of the pump is directly connected to the outlet flange of the reactor or as a low NPSH version, where the pump is connected between the pump and reactor flanges, in order to achieve an even shorter path and larger port. There are two types of Poly: a) Standard design: The suction...

Pump Sizes From 22/22 (4.7 cm3/rev) up to 360/360 (25.000 cm3/rev). Intermediate sizes, with wider gear wheels for lower differential pressure, are available as standard, e.g. 152/254 (3.170 cm3/rev). Operating Parameters Viscosity: Suction Pressure: Differential Pressure: The values listed are standard values and must not coincide under certain circumstances. Others values are available upon requests. Applications CHEM • Transfer • Metering • Increase pressure • Metering • Transfer Granulation Spinnery Fiber production Pre-polymer discharge and transfer

Low-NPSH-Design The loss of pressure on the suction side of the pump is dependent upon a number of factors. Parameters like viscosity and flow rate are largely predetermined by the process. According to the Hagen-Poiseuille equation, the pressure loss is linearly proportional to the length of the inlet path and inversely proportional to the fourth power of the diameter. The unique WITTE low NPSH version utilizes this knowledge and offers an extremely large diameter and short suction inlet. With the Low NPSH version, the connecting flange is foreseen as a loose flange and is located on the...

Vacuum viscoseal with buffered Stuffing Box The standard double mechanical seal can be used for pressures from vacuum up to 15 bar (210 psig). The seal can handle viscosities from 0,2 up to 1.000.000 cp (mPas). Maximum temperature of the liquid is about 300°C. For higher pressures and temperatures special designs exist. Suction Pressure: Vacuum up to 15 bar (abs) (218 psig) Vacuum viscoseal with buffered lip seal The vacuum viscoseal is a special version of the viscoseal and can also be provided with heating or cooling. The return flow to the suction side is adjusted by means of a needle...

The herringbone gear design The Herringbone Gears The herringbone gears reduces the pulsation of the medium being conveyed in comparison to straight and helical gears. This is a great advantage, particularly for polymers. Products with a high solids content are conveyed better, as the product is more easily displaced from between spaces between the teeth. The polymer is also subjected to less stress. This is particularly advantageous for highly sensitive polymers, as both shearing and heating effects are reduced during the pumping process. Existing gear pumps can be converted to herringbone...

POLY-Dimensions „Classic“ Size/Spec. displacement volume/Capacity Pump size * (Depending on the fluid characteristics and operating conditions)

Driving speed limit The speed limit is strongly dependent on viscosity and suction pressure Spec, displacement volume (ccm/U) WITTE PUMPS & TECHNOLOGY GmbH Lise-Meitner-Allee 20 D-25436 Tornesch / Hamburg / Germany WITTER PUMPS & TECHNOLOGY