Weekly Topic 10.11.15, Episode 3: What are the advantages of shielded pumps and conventional centrifugal pumps?

Shielded pumps are used to transport toxic media and prevent leaks; they do not leak, but are relatively expensive. Centrifugal pumps can generally be used in most environments, with a certain level of leakage. A low-temperature medium can also be used.

Hehe, I was at a DME factory in Songyuan, Jilin, for over ten days; there I saw shielded pumps and learned a bit about them. Shielded pumps also fall under the category of centrifugal pumps; they simply combine the motor and the impeller together. They have no moving seals, which means there is no leakage. They are suitable for transporting flammable, explosive, valuable, or toxic substances. Centrifugal pumps, on the other hand, can experience leakage ； The efficiency of shielded pumps is lower than that of ordinary centrifugal pumps ； Shielded pumps are relatively expensive ； There are indicators when the bearings of shielded pumps fail, which is relatively straightforward; whereas the detection of bearing failures in centrifugal pumps relies on experience

The advantage of shielded pumps is leaklessness, while the disadvantages are high purchase costs, unsuitability for high-temperature conditions, and limited power capacity. Ordinary centrifugal pumps are efficient, have a high flow rate, simple structures, are easy to maintain, and can be used in a wide range of applications. However, to ensure no leaks, many chemical plants still prefer to use canned pumps or magnetic drive pumps.

The advantage of both magnetic drive pumps and shielded pumps is that they are leak-free pumps; their common disadvantages are high purchase costs, unsuitability for high-temperature conditions, and limited power capacity. Magnetic pump requires that the medium be clean, free of solid particles. Centrifugal pumps have a wide range of applications, but to ensure no leaks, appropriate measures need to be taken in the shaft seal system.

The advantage of a shielded pump is that it is leak-free, while the disadvantages are high purchase costs, unsuitability for high-temperature conditions, and the limitation on maximum power level. Centrifugal pumps have a wide range of applications, but to ensure no leaks, appropriate measures need to be taken in the shaft seal system.

Advantages of shielded pumps: (1) Fully enclosed. There are no dynamic seals in the structure; only static seals are present at the pump’s casing, which enables complete leak-free operation. This makes it particularly suitable for transporting flammable, explosive, valuable liquids, as well as toxic, corrosive, and radioactive liquids. (2) High safety. Both the rotor and the stator are equipped with shielding sleeves that prevent them from coming into contact with the material; even if these shielding sleeves are damaged, there is no risk of external leakage. (3) Compact structure with low floor area. The pump and motor are integrated; no centering is required for disassembly or assembly. It has low requirements for the base and foundation, requires little routine maintenance, and results in low maintenance costs. (4) It operates smoothly, with low noise, and requires no lubricant. Due to the absence of rolling bearings and motor fans, no lubricant is required, and it produces low noise. (5) Wide range of applications. It can meet the requirements for various operating conditions such as high temperature, high pressure, low temperature, and high melting point. Advantages of centrifugal pumps: (1) Continuous and uniform flow rate, stable operation, and easy to adjust. (2) High rotational speed; can be directly connected to electric motors or steam turbines. They have a simple and compact structure, and their size and weight are much smaller than those of reciprocating pumps with the same flow rate, resulting in lower costs. (3) Not sensitive to impurities, have few vulnerable components, and are easier to manage and maintain.

The advantage is no leakage, while the disadvantages are high energy consumption and low utilization efficiency.

Take a look. . . . . . . . . . . . . . .

(1) Fully enclosed. There are no dynamic seals in the structure; only static seals are present at the pump’s casing, which enables complete leak-free operation. This makes it particularly suitable for transporting flammable, explosive, valuable liquids, as well as toxic, corrosive, and radioactive liquids. (2) High safety. Both the rotor and the stator are equipped with shielding sleeves that prevent them from coming into contact with the material; even if these shielding sleeves are damaged, there is no risk of external leakage. (3) Compact structure with low floor area. The pump and motor are integrated; no centering is required for disassembly or assembly. It has low requirements for the base and foundation, requires little routine maintenance, and results in low maintenance costs. (4) It operates smoothly, with low noise, and requires no lubricant. Due to the absence of rolling bearings and motor fans, no lubricant is required, and it produces low noise. (5) Wide range of applications. It can meet the requirements for various operating conditions such as high temperature, high pressure, low temperature, and high melting point.

1. Shielded pumps have no leaks and good stability, but they are expensive; if a problem occurs, the repair costs could be used to purchase a centrifugal pump. Additionally, the efficiency of shielded pumps is lower than that of centrifugal pumps.