• Model Number: CNPB80
• Brand Name: kenshine-pump
• Place of Origin: Shanghai, China
• Minimum Order Quantity: 1set
• Supply Capacity: 300SETS/month
• Payment: T/T in advance
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CNPB80 Canned motor centrifugal chemical pump no leakage Description

Canned motor pump no leakage chemical pump

Chemical canned pump is a sealless pump, with a sealed working environment. Its working mode is different from that of centrifugal pump, but no leakage is its biggest characteristic.

Working principle, advantages and disadvantages, structure and classification of chemical canned pumps

1、 Working Principle of Chemical industry canned motor Pump

The drive of an ordinary centrifugal pump is to connect the impeller shaft of the pump with the electric shaft through a coupling, so that the impeller and the motor rotate together and work. The chemical industry canned motor pump is a sealless pump, and both the pump and the drive motor are sealed in a pressure vessel filled with the pumped medium. This pressure vessel is only statically sealed, and a set of wires provides a rotating magnetic field and drives the rotor. This structure cancels the rotary shaft sealing device provided by traditional centrifugal pumps, so it can be completely leak free.

2、 Advantages of canned motor Pumps

1. Totally enclosed: The overall structure is sealless, with only static sealing at the pump casing, making it completely leak free. It is particularly suitable for transporting flammable, explosive, precious liquids, toxic, corrosive, and radioactive liquids.

2. Smooth operation, low noise, no need to add lubricating oil: Since there are no rolling bearings and motor fans, no need to add lubricating oil.

3. High safety: The rotor and stator each have a shielding sleeve to prevent the motor rotor and stator from contacting materials. Even if the shielding sleeve breaks, there is no risk of leakage.

4. Compact structure and small footprint: The pump and motor are integrated, making disassembly and assembly very convenient. Low requirements for the base, and less daily maintenance work, maintenance costs are also relatively low.

5. Wide application range: It can meet requirements for various working conditions such as high temperature, high pressure, low temperature, and high melting point liquids

3、 Disadvantages of canned pump

1. Due to the use of sliding bearings in canned pumps and the use of transported media for lubrication, canned pumps are unlikely to be able to transport non lubricated media. Generally, the viscosity suitable for shielded pump media is 0.1~20mPa. s.

2. The efficiency of canned pumps is generally lower than that of single ended mechanical seal centrifugal pumps (IH chemical centrifugal pumps, IHF chemical centrifugal pumps), but approximately equivalent to that of double ended mechanical seal centrifugal pumps.

3. Operating under low flow conditions for a long time can greatly reduce work efficiency, resulting in heat generation, liquid evaporation, and dry running of the pump, which can damage the sliding bearings.

4、 Structure of canned pump

Chemical industrial canned motor pump is a type of centrifugal pump, mainly composed of pump body, impeller, stator, rotor, front and rear guide bearings, and thrust disk. The motor and pump are integrated, the stator and rotor surfaces are wrapped with nonmagnetic thin-walled materials, and the rotor is supported by front and rear guide bearings and immersed in the conveyed medium. The rotor shaft end is equipped with an impeller, forming a structure without a shaft seal to achieve the purpose of leak free transportation.

5、 Type of canned motor pump

According to the different temperatures, pressures, particles, and viscosities of the media, chemical canned pumps can be divided into the following forms:

1. Basic type (standard type)

The transmission medium temperature does not exceed 120 ℃, and the lift does not exceed 200m. Other types of canned pumps are modifications and improvements based on the basic model.

2. Reverse circulation type

This type of canned pump has the opposite direction of fluid flow for bearing lubrication, cooling, and motor cooling compared to the basic type. The main characteristic of reverse circulation pumps is that they are not prone to cavitation, and are suitable for conveying easily vaporized liquids, sometimes referred to as easily vaporized pumps.

3. High temperature type

The temperature of the conveying medium can be as high as 450 ℃. Generally, a cooling water jacket is added outside the shielded motor and a cooling sleeve is added to the external circulation pipe to cool the high-temperature circulating liquid to reduce the temperature of the motor and bearing. In situations where the power is not high, some manufacturers do not use coolant, but instead install heat dissipating fins outside the motor to adapt to the operating conditions. The operating temperature should generally not exceed 400 ℃.

4. High melting point type

A jacket is provided at the hydraulic end and the motor side of the pump, which can be filled with steam or high-temperature liquid to prevent crystallization of high melting point liquid. The external circulation pipe of the pump should also be provided with thermal insulation (heating) jackets.

5. High pressure type

The shell of the canned pump is a high-pressure container that allows the pump to withstand high system pressure. In order to support the shield under internal high pressure, the stator coil itself can be used to withstand pressure. It can also be made into a shielded pump operating under high temperature and pressure.

6. Self priming type

The suction inlet of the pump is much higher than the center of the impeller. After stopping the pump, when there is no liquid in the suction pipeline, the impeller and the enlarged pump chamber are always filled with liquid. When restarting, the pump can operate without filling with water. Self priming pumps are particularly suitable for extracting liquids from underground containers.

In addition, according to different methods, it can also be divided into submerged type, slurry type, high-pressure pipeline type, and various types of canned pumps specifically used for ships, nuclear power plants, and absorption refrigeration devices. It can also be divided into vertical, horizontal, online, single stage, multi-level, and other different types.

7. Multistage type

Equipped with multiple impellers, it is suitable for high lift fluid transportation, with a high lift of up to 600m.

8. Mud type

Suitable for conveying liquids mixed with a large amount of mud.

According to the high-pressure liquid discharged from the impeller, it is used as a circulating cooling liquid to carry away heat. According to the different media, circulating cooling is divided into three types: positive circulation, reverse circulation, and external circulation.