Twin Screw Dry Vacuum Pump

1. Overview
The vacuum system can not meet the general requirements of corrosion resistance and clean without oil, replaced by vacuum system large oil vacuum system has been no clean oil, no oil, dry vacuum cleaner products will accelerate the replacement of water ring pump, reciprocating pump, oil seal mechanical pump. Screw vacuum pump is a non-contact type dry pump, 1990s occurred at the beginning of an ideal pump, due to its wide range of pumping speed, simple and compact structure, pumping chamber components without friction, long life, low energy consumption, no oil pollution etc..

Screw vacuum pump is a studio consisting of a pair of parallel helical rotor and pump body, no friction between the rotor and the pump body and keep a certain gap in the seal cavity is formed between the two rotor and pump body, when the rotor rotates the gas seal cavity continuously to squeeze the air outlet. Because of the need of lubricating oil or water seal screw vacuum pump, the pump chamber completely without oil, so oil free dry screw vacuum pump is a vacuum pump, no oil clean occasions, chemical and pharmaceutical of solvent recovery process in semiconductor and electronic industry has the incomparable superiority, it is the product of reciprocating pump, Water Pump, oil seal vacuum pump, rotary vane vacuum pump and roots blower update.

A lead screw vacuum pump is the equivalent of a screw pump, vacuum pump multiple lead equivalent Multistage Pump series, compared with the claw type dry vacuum pump vacuum pump, roots vacuum pump multi-stage series, because there is no internal passage between levels of pump screw vacuum pump, which is directly to the gas from the suction side to push the exhaust side, so the pumping condensable gas, with gas and dust particles when no blockage and easy cleaning. The gas pressure is higher than that of the exhaust gas, and the pressure of the gas is higher than the source. This design allows the discharge of the gas will not be mixed with oily substances. The power of the motor is transmitted to the drive shaft through a coupling device, and the main rotating shaft is transmitted to the driven shaft through the timing gear.

Two. Structural principles and characteristics
Screw type oil-free mechanical vacuum pump is also called dry screw vacuum pump, is driven by a gear meshing rotation of the left and right screw synchronous reverse screw without contact for high speed rotation, the screw pump shell and meshing the spiral groove is divided into a plurality of space, forming a plurality of stages, gas in each slot equal in (column pitch) transmission of motion, but without compression, only the end of the spiral structure of screw compression of gas. The pressure gradient can be formed at all levels of the screw in order to disperse the pressure difference and increase the compression ratio. Each clearance and pump speed has a great impact on the performance of the pump. In the design of the various parts of the gap, has been taken into account expansion, processing and assembly accuracy and working environment (such as the extraction of dust containing gas), etc.. No oil in the pump cavity, no pollution to the vacuum system, which is conducive to the recovery of exhaust gas, environmental protection.

The screw rotor
The rotor is divided into equal pitch and variable pitch structure of two types, type LG pitch LGP variable pitch rotor, rotor, rotor are made by the five axis machining center equipment precision processing, after processing through the dynamic balance test of precision grade G1, ensure the equipment performance. The screw rotor material is made up of the following three categories according to different working conditions:
A, high grade spheroidal graphite cast steel plated NI-P alloy, suitable for general gas alkaline medium or slightly acidic medium.
B, 316L and other stainless steel materials, suitable for stainless steel does not respond to the strong acid and alkali media.
C, TA, TC series of titanium materials, suitable for most of the acid and alkali medium.

- timing gear
The gear ratio is one of the most important parts of the screw pump, it can keep the fixed gap between the screw rotor and rotor. After carburizing and quenching treatment, the gear tooth surface is polished with special high precision gear polishing equipment to reduce the noise, and the gear precision is up to 5-6 level.

- bearing
Fixed end bearing for SKF double row thrust ball bearing, extended end bearing for high load roller bearings. These bearings are able to withstand high speed and high load operation, and can accurately maintain the gap between the gear and the rotor.

- seal
The sealing device is composed of a multi lip dry stainless steel rotary seal and a gas sealing compound composition. Composite sealing device can effectively prevent oil substances before entering the shell of the end plate, while preventing the pumped medium into the gear lubrication of the bearing cavity, greatly extend the service life of the pump and reduce maintenance, improve equipment reliability.

The lubricating oil
Vacuum pump gear box using oil lubrication, oil should be added to the oil mirror above the center line. If the oil is too small, the bearings, gears and mechanical seals will be damaged due to abnormal friction. Therefore, when the pump is not working, please check the oil and oil pollution status, to determine whether the need to increase or replace the lubricating oil. The lubricating oil will be evenly distributed along with the rotation of the timing gear and the lubrication of bearings and mechanical seals.


Characteristic:
1, clean working cavity without lubricating oil, for dry vacuum pump, is conducive to the recovery of medium, can acquire clean vacuum, no oil, in the process of wastewater discharge, no pollution to the environment, environmental protection vacuum equipment.
2, high vacuum degree: optimization design of rotor profile, using the German five axis machining center of precision machining, single pump limit pressure type LG = 1Pa, LGP = 5Pa, high vacuum pumping capacity, high working efficiency, low power consumption.
3, anti-corrosion (patented technology): needle different extraction media, over flow components are titanium, stainless steel, nano ceramic, spraying
NIP alloy, such as a variety of materials and anti-corrosion coating to choose from, can be drawn in a variety of corrosive, can be condensed chemical industry,
Particularly suitable

Naipu ZG series pumps are cantilevered,horizontal,centrifugal slurry pumps. They are used international advanced solid-liquid two-phase flow theory and were designed using the Minimum-Wear Principle. The flow parts of this pumps are suitable for the flow of state media for it's set shape, which reduces hydraulic loss of eddy and impact, both in pump and along the pipeline; so reduced friction of flow parts, lower noise and vibration of the pump translates into improved hydraulic efficiency.

Typical Applications---

Electric Power
Constructional Material
Mine Coal
Coal washing
Sand Reclamation

Sugar Beet

NP-ZG Slurry Pump Construction Component

Main Part Number At The Drawing
 

1 Coupling 2 Shaft 3 Bearing Housing 4 Disassembly Ring 5 Expeller 6 Rear Liner Plate 7 Volute Casing 8 Impeller

9 Front Liner Plate 10 Front Casing 11 Rear Casing 12 Stuffing Box 13 Water Seal 14 Base 15 Support

Materials of Construction
 

	VOLUTE	IMPELLERS	BASE	EXPELLER	EXPELLER RING	SHAFT SLEEVE	SEALS
Standard	High Chrome Alloy	High Chrome Alloy	Cast Iron	Chrome Alloy or SG Iron	Chrome Alloy or SG Iron	SG Iron	Natural Rubber
Options	SG Iron	SG Iron	Mild Steel Fabricated	SG Iron	SG Iron	EN56C Ferralium Hasteloy C Ceramic Stellite Chrome Oxide	Nordel Neoprene Viton Butyl EPDM

 ZG SLURRY PUMP SELECTION CHART

     Note:Approximate performance for clear water,to be used for primary selection only.

ZG SLURRY PUMP PERFORMANCE PARAMETERS

ZG High Efficiency Slurry Pump

ZG High Efficiency Slurry Pump, High Efficiency Slurry Pump, Ah Slurry Pump, High Head Slurry Pump

Shijiazhuang Naipu Pump Co., Ltd. , https://www.naipu-pump.com