Stainless steel vane pump is a kind of equipment commonly used to transport corrosive liquids. It is widely used in chemical, pharmaceutical, environmental protection and other fields. The following will introduce its working principle and structural composition in detail:

 

1. Working principle

The working principle of stainless steel vane pump is based on the basic principle of centrifugal pump. It transports liquid through the centrifugal force generated by the rotation of impeller. The specific process is as follows:

Impeller rotation generates centrifugal force

When the motor drives the impeller to rotate at high speed, the liquid in the impeller is subjected to the centrifugal force and is thrown to the edge of the impeller. It obtains kinetic energy and pressure energy through the blade push, and then flows from the impeller outlet along the pump casing to the discharge pipe.

Energy conversion and transportation

The mechanical energy of the impeller is transmitted to the liquid through centrifugal force, so that the kinetic energy of the liquid is converted into pressure energy, thereby realizing the lifting and long-distance transportation of the liquid. The corrosion resistance of stainless steel ensures the long-term stable operation of the pump when transporting corrosive media.

 

2. Structural composition

The structure of stainless steel vane pump is mainly composed of the following parts. The functions and characteristics of each part are as follows:

(I) Flow-through components

Impeller

Function: Directly do work on the liquid, which is the core component of the pump.

Structure: Usually a closed or semi-closed impeller, cast from stainless steel (such as 304, 316L, etc.), the shape and number of blades are designed according to the flow and head requirements to ensure efficient energy conversion.

Features: Smooth surface, strong corrosion resistance, can reduce liquid flow resistance and wear.

Pump casing (pump body)

Function: Collect the liquid thrown out by the impeller and guide it to the discharge pipe, while converting the kinetic energy of the liquid into pressure energy.

Structure: Made of stainless steel, spiral (volute), with smooth internal flow channel to reduce hydraulic loss.

Features: High strength, high pressure resistance, and can withstand the impact force generated by liquid flow.

Suction pipe and discharge pipe

Function: Connect the suction tank and the discharge pipe respectively to form a liquid flow path.

Structure: The inlet of the suction pipe is usually equipped with a filter to prevent debris from entering the pump; a valve can be installed on the discharge pipe to control the flow.

Features: The pipe material is consistent with the pump body to ensure corrosion resistance, and the connection is sealed with flanges or threads to prevent leakage.

(II) Driving and supporting components

Motor

Function: Provide power for the pump and drive the impeller to rotate.

Type: Select ordinary motor or explosion-proof motor (such as flammable and explosive occasions) according to the use environment, and the motor power is determined according to the flow rate and head of the pump.

Connection method: Rigidly connected to the pump shaft through a coupling, or a direct connection structure is adopted to reduce transmission loss.

Pump shaft

Function: Transmit the torque of the motor to the impeller to drive the impeller to rotate.

Structure: Made of stainless steel or high-strength alloy steel, the shaft diameter is designed according to the torque and speed to ensure sufficient strength and rigidity.

Support: Usually supported by bearings, the bearings are installed in the bearing box and lubricated by lubricating oil or grease to reduce friction and heat.

Bracket and base

Function: Support the pump body and motor to ensure stable installation of the pump.

Structure: The bracket is generally made of stainless steel and fixed on the equipment foundation or the top of the container; the base is used to fix the motor to ensure the coaxiality of the shaft and the motor.

Features: The structural design is compact, easy to install and maintain, and the bracket length can be adjusted according to the underwater depth.

(III) Sealing and protective components

Mechanical seal (or packing seal)

Function: Prevent liquid from leaking from the connection between the pump shaft and the pump housing, and prevent external impurities from entering the pump.

Type:

Mechanical seal: It is composed of a dynamic ring, a static ring, a spring, a sealing ring, etc. It has good sealing effect and small leakage, and is suitable for highly corrosive and high-pressure occasions.

Packing seal: It uses polytetrafluoroethylene (PTFE) or asbestos packing, and seals by pressing the gland. It has a simple structure, but the leakage is large, and the packing needs to be replaced regularly.

Features: Sealing components made of stainless steel (such as metal sealing rings) can enhance corrosion resistance and wear resistance.

Sheath pipe (submerged part)

Function: Protect the pump shaft and mechanical seal from medium corrosion and erosion in the submerged environment, and guide the flow of liquid.

Structure: It is sleeved on the outside of the pump shaft and connected to the pump housing. It is made of stainless steel and the length is customized according to the submerged depth.

Features: The inner wall is smooth to reduce liquid resistance, and reinforcing ribs can be added to the outer wall to increase rigidity.

(IV) Auxiliary components

Bearing box

Function: To accommodate bearings and provide lubrication, and to cool the heat generated by bearings during operation.

Structure: Made of stainless steel, equipped with oil level observation window, oil filling hole and oil drain hole. Some models are equipped with cooling water pipes to cool down through circulating water.

Coupling protective cover

Function: To protect the coupling from interference from external debris, and at the same time prevent operators from contacting rotating parts to ensure safety.

Material: Stainless steel or engineering plastics, with good protective performance.

 

3.Structural characteristics and advantages

Submerged design: The flow-through parts of the pump are immersed in the liquid, and the pump can be started without filling the pump, which is suitable for occasions with large changes in liquid level.

Strong corrosion resistance: All stainless steel materials (such as 316L) can resist corrosive media such as acids, alkalis, and salts, and extend service life.

Easy installation and maintenance: Vertically installed on the top of the container, it occupies a small area. When repairing, you only need to lift the pump body out of the liquid without disassembling the pipeline.

Stable operation: The dynamic balance design of the impeller and pump shaft reduces vibration, and the high reliability of the mechanical seal reduces the risk of leakage.