POLY - High-Pressure Discharge Gear Pump Brochure

CHEMEXTRUPOLYBOOSTERPUROPOLY Discharge Gear PumpPOLYPOLY high-pressure gear pump for the discharge of medium to high viscose media from the reactor. The extra large inlet opening gua-rantees 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.POLYTechnical FeaturesHousing: Stainless steels, carbon steel, optional: surface coatingGears: Nitrided steel, tool steel, optional: special steel, surface coating, helical gearing, herringbone gearingFriction Bearings: Tool steel, Al-bronze, NiAg (nickel-silver), optional: special materials, surface coatingShaft Seals: Vacuum viscoseal, buffered stuffing box, buffered lip seal combination of vacuum viscoseal and buffered stuffing box, or vacuum viscoseal with buffered lip seal, double and buffered mechanical seal,Heating Systems: Heat transfer oil, steamApplication ExamplesPolymers: PET, PBT, PA, PC, PS, SAN, ABS, HIPS, PP, PE, POM, BiopolymersThere are two types of Poly:a) Standard design: The suction flange is also the fastening flange to the reactor.b) The Low NPSH design: In this case, the fastening flange is designed as an aligning flange and is seated on the delivery side of the pump. The pump is clamped between the aligning flange and the reactor flange. This design provides an extremely large and short suction opening, promoting productflow. The opening can be circular, square or rectangular. ill. Poly SPump SizesFrom 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 ParametersViscosity: Up to 40.000 PasTemperature: Up to 350 °C (662 °F)Suction Pressure: Vacuum to max. 15 bar (218 psig)Differential Pressure: Up to 250 bar (3.625 psig)The values listed are maximum values and must not coincide under certain circumstances.ApplicationsPOLYPre-polymerdischarge and transferCHEM • Transfer• MeteringPOLYPre-polymerdischarge and transferBOOSTER• Increase pressure• Metering• TransferGranulationSpinneryFiber productionill. Poly classicLow-NPSH-DesignThe 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 pressure side of the pump. The pump itself is connected between the loose flange and the reactor flange. This configuration allows an extremely large diameter, short suction inlet to be incorporated into the housing. The shape of the inlet is variable and can for example be round, quadratic orsquare. Due to the fact that the pressure losses at the suction side have been reduced to a minimum,even critical applications can be reliably realised, e.g. discharging high viscous or foaming melts. Viscosity: 10 - 40.000 PasTemperature: max. 350 °C (662 °F) Suction Pressure: Vacuum up to 15 bar (abs) (218 psig)Type of SealsDouble mechanical seal DDThe standard double mechanical seal can be used for pres-sures from vacuum up to 15 bar (210 psig). The seal can handle viscosities from 0,2 up to 1.000.000 cp (mPas). Ma-ximum temperature of the liquid is about 300°C. For higher pressures and temperatures special designs exist. 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 valve, so that the choked product forms a barrier. This makes it possible to operate the pump with vacuum conditions on the suction side. Due to the fact that it is a dy-namic seal, it is often combined with a buffered stuffing box. This combination prevents air from entering the reactor, even when the pump is at a standstill.As an alternative, the vacuum viscoseal can also be com-bined with a lip seal instead of a stuffing box. The buffer fluid of this static shaft seal acts as barrier. If the pump is stopped for a short time this design prevents air getting sucked in the pump through the shaft seal.Viscosity: 10 - 20.000 PasTemperature: max. 250 °C (527 °F)Suction Pressure: Vacuum up to 15 bar (abs) (218 psig)Viscosity: 0,2 - 1.000.000 mPasTemperature: max. 300 °C (580 °F) Suction Pressure: Vacuum up to 15 bar (abs) (218 psig)Vacuum viscoseal with buffered lip sealVacuum Viscoseal with buffered Stuffing BoxThe Herringbone GearsThe 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 gears. The shafts and friction bearings could be easily replaced. Sizes available are: 4 (45/45) to 11 (224/224). The „O“ design displaces the medium towards the centre.The „X“ design displaces the medium towards.The herringbone gear designAdvantages at a glance:• Less pulsation• Less stress on the polymers /shearing• Decreased product heating effect• Existing pumps can be convertedSpur gears?p = 5,0 bar (72 psi)Helical gears?p = 2,8 bar (40 psi)Herringbone gears?p = 0,6 bar (9 psi)Herringbone gears: comparison of pulsationExample: comparison of pulsationPump size suction sideoutsideØ Asuction sideinsideØ Bpressure side inside Ø CHeightD46,3-4 315 125 50 26092,6-5 320 150 68 290176-6 380 175 80 350371-7 450 200 100 400716-8 520 250 125 4301482-9/1 584 300 150 5303200-10 730 400 200 6406100-11 915 500 250 77012000-12 1150 600 300 960POLY-Dimensions „Classic“POLY-Dimensions „POLY- S“Pump size suction sideoutsideØ Asuction sideinsideØ Bpressure side inside Ø CHeightD371-7 380 200 80 377716-8 450 250 100 3941482-9/1 520 300 125 4713200-10 580 350 150 5406100-11 715 400 200 63512000-12 915 500 250 77018L-320/320 1035 600 250 85025L-360/360 1150 700 300 950Pump size Spec. displace-ment volume (cm3/rev)Capacity (l/h)*1 (22/22) 4,7 3 - 562 (28/28) 10,2 6 - 923 (36/36) 25,6 15 - 2304 (45/45) 46,3 28 - 4175 (56/56) 92,6 55 - 7226 (70/70) 176 105 - 13707 (90/90) 371 222 - 28908 (110/110) 716 430 - 47009 (140/140) 1.482 900 - 885010 (180/180) 3.200 1920 - 1700011 (224/224) 6.100 3660 - 3200012 (280/280) 12.000 6590 - 5800018L (320/320) 18.000 13000 - 4000025L (360/360) 25.000 17000 - 52000POLY-DimensionsSize/Spec. displacement volume/Capacity* (Depending on the fluid characteristics and operating conditions)WITTE PUMPS & TECHNOLOGY GmbHEsinger Steinweg 44 aD-25436 Uetersen / Hamburg / GermanyT: +49 (0) 4122 / 92 87- 0 F: +49 (0) 4122 / 92 87- 49info@witte-pumps.comwww.witte-pumps.com05/2012 POLY ENG REV1