Duwan G70-1 ModelPrinciple and Structure of Screw Pumps：

Once the motor starts, the gears on the motor shaft drive the impeller to rotate, causing the liquid inside the pump to be吸入 due to centrifugal force. Subsequently, the liquid is propelled forward by the rotating screw pump.

During the meshing process, fluid is drawn into the pump and flows out through the sealed cavity formed between the stator and the rotor; during the suction and discharge processes, the fluid exchanges positions, filling the entire volume with liquid.

1. Single Screw Pump Set: The single screw pump consists of a stator and a rotor. The stator is a cavity device formed by浇筑nitrile rubber and bonding it to the outer casing of the cylinder. The inner surface of the stator is a double helical curved surface. The rotor is made from alloy steel rod, precision turned, chrome plated, and polished, available in hollow and solid configurations. The stator and rotor are eccentrically placed with an eccentric distance, fitting with the outer surface of the rotor to form multiple sealed chambers. These chambers are used to fill working fluid, and as the rotor rotates, it continuously moves along the axis, converting mechanical and hydraulic energy.

2. Twin-screw Pump Structure and Principle: Twin-screw pumps are divided into external bearing structure and internal bearing structure. They are very similar to gear pumps, with the driving screw rotating to drive the driven screw. The liquid is intercepted in the meshing chamber, propelled along the screw shaft, and then forced out through the central oil outlet.

Duwan Environmental ProtectionG TypeScrew Pump Introduction：

A screw pump is a positive displacement pump consisting of a rotating screw and a rotor fixed within a stator, with a certain gap between them. As the motor's rotational motion passes through the rotor, it drives the screw to rotate as well. The teeth on the screw mesh with the teeth on the rotor to form a sealed cavity, creating a pressure difference within the stator. This causes the liquid to enter the screw cavity from the stator's inner hole, and the screw then pushes the liquid out of the screw cavity. Also known as a volumetric pump or screw discharge pump.

Advantages of Screw PumpsUsage:

Bolt pumps offer advantages such as low flow rate, low noise, minimal vibration, long lifespan, and high mechanical efficiency, making them widely used in systems like ships, passenger elevators, precision machine tools, and hydro turbine speed regulation.

Screw pump classifications：

Single-screw, double-screw, and triple-screw pumps, categorized by the number of screws.Hydraulic pumps and conveying pumps are categorized by their applications.

Screw pump installationDescription:

1. AssembledScrew threadParts that require oil lubrication during pump operation, such as: bearings, universal joints, etc., filled with grease, usually to 2/3 of the cavity volume.

2. Inspect that all connections of the equipment assembly are securely fastened.

3. Screw pump units (including pumps, reducers, and prime movers installed independently) should have a solid, stable foundation. The units must be securely mounted on the foundation to prevent severe vibration during operation.

4. Inspect for any gaps between the universal joints and strictly control the neutral alignment of the two shafts; the跳动 of the outer diameter of the universal joint must not exceed 0.1mm.

5. During the pipeline design of the pump, it is advisable to leave a space at the pump outlet that is longer than the stator length and to make the pipeline removable for ease of maintenance and replacement of the stator.

6. Identify the pump's inlet and outlet correctly before connecting the inlet and outlet piping.

Screw pump start-up：

Before starting, check that the intake tube section and instrument接头 connections are sealed.

2. Before the first start-up, after disassembly and reassembly, or if the pump has not been started or used for a prolonged period, and the medium inside the pump has been drained, the intake chamber should be filled with medium. Rotate the pump shaft by hand or with a tool several times before starting. This prevents the pump from starting with no medium or only a small amount of medium, which could create a lubricating film of medium between the stator and rotor surfaces, avoiding dry friction between them and preventing damage to the stator or an excessively high starting torque that makes the pump unable to start or reduces the pump's suction performance.

3. For conveying highly viscous media, the pump's jacket layers should be heated prior to start-up to reduce the viscosity of the residual media within the pump, facilitating easier operation.

4. Inspect the original motor's rotation to prevent reversal.

Before starting, all valves on the inlet and outlet pipelines must be fully opened, ensuring the pipeline is unobstructed.

Screw pump operation：

Check if the bearing high temperature exceeds the temperature specified in the product manual.

2. Check if the shaft seal leakage exceeds the requirements specified in the product manual.

3. Pay attention to the indication value of the vacuum pressure gauge on the import pipeline; the needle should not have剧烈jiggling. Check if the pipeline installed for the vacuum pressure gauge is properly aligned.

4. Pay attention to any abnormal noise or vibration from the pump; if cavitation occurs, stop the pump immediately.

5. Pay attention to any sudden changes in the pump's flow and pressure, and check them promptly.

Screw pump usage：

After shutting off the power, close the intake valve and the exhaust valve.

2. Pumps for conveying high-viscosity, particulate, and corrosive media should have the pump contents drained after shutdown, cleaned, and prevented from sedimentation or damage to the pump.

3. For conveyance of food, pharmaceuticals, and other health-related substances, after shutdown, the pump should be drained completely, flushed thoroughly, leaving no residual medium to prevent bacterial growth.

4. When the ambient temperature reaches or falls below the freezing point of the medium, after shutdown, the medium in the pump should be completely drained to prevent the pump from cracking due to freezing.

5. When a screw pump is to be left unused for an extended period, drain the medium inside, add a small amount of lubricating oil, turn the pump shaft by hand or with a tool, remove the rotor, and coat it with grease for protection.

6. Rubber rotors must not be exposed to direct sunlight or temperatures below -20°C to prevent damage. Pay attention to the rotor's shelf life and do not use worn-out rotors.