The pumps used in the high and low temperature integrated machines and high-temperature constant temperature circulation tanks produced by our company are common dynamic equipment in industrial production, and their usage conditions are becoming increasingly high in some demanding situations nowadays. Shielded pumps are becoming increasingly common in chemical plants due to their lack of shaft seals, which allows for zero leakage. Someone asked, what are the differences between shielded pumps, magnetic pumps, and centrifugal pumps? We will focus on talking about it for everyone. The sealed or leak free structure of the shielded pump makes it suitable for pumping flammable, valuable, corrosive, and toxic liquids.High temperature water type mold temperature machineBecause shielded pumps are leak proof, they contribute to the safety of flammable liquid systems; For valuable and corrosive liquids, it has a more prominent economic effect.
Differences of shielded pumps
1. Integrated structure of motor and water pump, with the water pump and motor connected coaxially;
2. The inner side of the motor stator and the outer side of the rotor are equipped with shielding sleeves, and the inner side of the shielding sleeve is connected to the inside of the pump;
3. There are two installation methods: horizontal and vertical
4. The motor eliminates the cooling fan and cools the motor through circulating medium between the stator and rotor, while also using surface cooling on the motor base.
Advantages of shielded pumps
1. Fully enclosed. There is no dynamic seal in the structure, only a static seal at the pump casing, so it can achieve * no leakage, especially suitable for transporting flammable, explosive, valuable liquids and toxic, corrosive and radioactive liquids.
2. High security. The rotor and stator each have a shielding sleeve to prevent them from coming into contact with the material. Even if the shielding sleeve breaks, there is no risk of leakage.
3. Compact structure and small footprint. The pump and motor system are integrated, and there is no need to find the center for disassembly and assembly. Low requirements for the base and foundation, with minimal daily maintenance workload and low maintenance costs.
4. Smooth operation, low noise, no need to add lubricating oil. Due to the absence of rolling bearings and electric motor fans, there is no need to add lubricating oil and the noise is low.
5. Widely applicable. It can meet the requirements for various working conditions such as high temperature, high pressure, low temperature, and high melting point.
Disadvantages of shielded pumps
1. Due to the use of sliding bearings and lubrication with the conveyed medium, shielded pumps are not suitable for conveying media with poor lubricity. Generally, the viscosity of the medium suitable for shielded pumps is 0.1-20mPa. s.
2. The efficiency of shielded pumps is usually lower than that of single end mechanical seal centrifugal pumps, but roughly equivalent to that of double end mechanical seal centrifugal pumps.
3. Long term operation at low flow rates can result in low efficiency of the shielded pump, causing heat generation and evaporation of the liquid, leading to dry running of the pump and damage to the sliding bearings.
compare
Application scenarios of shielded pumps
1. In situations where the pressure is abnormal. When the suction side pressure of the pump is high and the difference between the suction side pressure and the discharge side pressure is small, using a stuffing box will bear additional stress.
2. In situations where high vacuum is required. If a stuffing box is used, air will enter through the stuffing box when the shaft is slightly eccentric or worn.
3. In situations where vacuum and pressure alternate operations. Packing boxes or sealing structures used for ordinary vacuum operation cannot be used for operation under pressure.
4. The occasion for handling valuable liquids. Liquid causes significant economic losses.
5. In situations where toxic liquids are handled. And the harm to life. If a stuffing box is used, a considerable amount of valuable liquid will be lost annually due to leakage. If a stuffing box is used, the leakage of toxic liquids will cause harm to human health,
6. In situations where explosive gases occur. Although flammable liquids such as gasoline, kerosene, jet fuel, etc. can be transported using a centrifugal pump with a rotating seal connected to an explosion-proof electric motor, leaked liquids and liquids that turn into vapor will make the entire site a hazardous area for explosion.
7. Dealing with radioactive liquids. Radioactive liquids are not allowed to leak from the stuffing box. In addition, many fillers are made of materials that cannot come into contact with radioactive liquids.
8. In situations where corrosive liquids are handled. In addition to local corrosion caused by leakage of the packing box, the process equipment may also be corroded by steam generated by corrosive liquid leakage.
9. In situations where hazardous liquids are handled. When harmful gases such as foul odor are generated due to the leakage of the stuffing box, it will create a severe situation where operations cannot be carried out.