What are the advantages and disadvantages of centrifugal pumps and progressive cavity pumps?

Advantages of progressive cavity pumps:

1) Low speed (generally 20r min 90r min), small mechanical wear, no cavitation.

2) The runner is wide enough to convey water containing solid matter.

3) The structure of the pump body is half-open, and the operation of the pump can be observed.

4) Suction side flow has little impact on hydraulic performance, no special requirements for the suction pool, the excavation depth of the foundation pit is small, the construction of hydraulic buildings is simple, and the civil cost is low.

Disadvantages of progressive cavity pumps:

1) Large volume and large area.

2) Restricted by machining conditions, the pump shaft can not be too long, so the pump head is low, generally not more than 10 meters.

3) The height of the suction surface and the outlet surface should not change too much, otherwise it will affect the work efficiency and increase the energy consumption.

Advantages of centrifugal pumps:

1) Compact structure.

2) Wide range Wide range of flow and head.

3) Suitable for mildly corrosive liquids.

4) Multiple control options.

5) Uniform flow, stable operation and low vibration. A foundation that does not require special shock absorption.

6) The cost of equipment installation, maintenance and overhaul is low.

Disadvantages of centrifugal pumps: generally there is no self-priming ability, and the pump needs to be filled with liquid or the pipeline pumped into a vacuum before it can start working.

Advantages of centrifugal pumps:

1. Compact structure.

2. Wide range of flow rate and head.

3. A variety of control options.

4. The flow is uniform, the operation is stable, and the vibration is small. A foundation that does not require special shock absorption.

5. The cost of equipment installation, maintenance and overhaul is low.

Disadvantages of centrifugal pumps:

1. There is no self-priming ability, and it should be filled with liquid when starting, and there is a phenomenon of air binding.

2. It is not suitable for small flow and large indenter, and it is not suitable for high viscosity.

Advantages of progressive cavity pumps:

1) Low speed (generally 20r min 90r min), small mechanical wear, no cavitation.

2. The flow channel is wide, which can convey water containing solid matter.

3. The structure of the pump body is half-open, and the operation of the pump can be observed.

4. The suction side flow state has little impact on the hydraulic performance, there is no special requirement for the suction pool, the foundation excavation depth is small, the construction of hydraulic buildings is simple, and the civil engineering cost is small.

Disadvantages of progressive cavity pumps:

1. The size is large and the floor area is also large.

2. Restricted by machining conditions, the pump shaft should not be too long, so the head is low, generally not more than 10m.

3. The height of the suction surface and the water outlet should not change too much, otherwise the work efficiency will be affected.

Increase energy consumption. <>

Centrifugal pumps and progressive cavity pumps are two common types of liquid transfer equipment, each with its own unique advantages and disadvantages. When choosing the right pump, it needs to be determined according to the actual application scenario, flow, head and other parameters. Here are the advantages and disadvantages of centrifugal pumps and progressive cavity pumps and their comparison.

Centrifugal pumps: advantages:

Simple structure: The structure of centrifugal pumps is relatively simple, which is easy to manufacture, install and maintain.

Smooth operation: The centrifugal pump can achieve smooth and continuous conveyance with less vibration and noise.

High efficiency: The centrifugal pump has high efficiency under medium and small flow rates and medium and low heads, reducing energy consumption and operating costs.

Diverse conveying media: Centrifugal pumps can transport a variety of media, such as clean water, sewage, oil, corrosive liquids, etc.

Disadvantages: Poor self-priming ability: centrifugal pumps need to be filled to start, which is not suitable for well water pumping and other occasions that require self-priming function.

Low efficiency at high head: Centrifugal pumps are less efficient at high head.

Progressive cavity pumps: advantages:

Strong adaptability: the progressive cavity pump has strong adaptability to the viscosity of the conveyed liquid, the content of gas and particulate impurities.

Smooth operation: The progressive cavity pump uses a spiral form to convey liquid, with a continuous and smooth flow rate and low vibration and noise.

Good self-priming ability: The screw pump has good self-priming ability, does not need to fill the pump, and is easy to start.

High head efficiency: The progressive cavity pump has high efficiency under high head conditions.

Disadvantages: Relatively complex structure: The structure of the progressive cavity pump is relatively complex, the manufacturing cost is high, and the repair and maintenance are relatively troublesome.

Limited conveying media: For highly corrosive liquids, progressive cavity pumps may require the use of special materials and are costly.

Comprehensive comparison: Application scenarios: Centrifugal pumps are suitable for municipal water supply, petrochemical, cooling and heating systems and other occasions.

The progressive cavity pump is suitable for the transportation of high-viscosity liquids, liquids containing gases and particulate impurities, such as oilfield oil production, chemical plants to transport high-viscosity raw materials, etc. Choose the right pump according to the actual application scenario.

Performance requirements: Centrifugal pumps have higher efficiency in low and medium head conditions, while progressive cavity pumps have higher efficiency in high head conditions. For occasions that require continuous, smooth conveying, centrifugal pumps have advantages; For applications where self-priming and conveying highly viscous liquids are required, progressive cavity pumps are more advantageous.

Cost & Maintenance: Centrifugal pumps have advantages in overall cost of use due to their simple structure and low manufacturing costs. However, due to the complex structure, the manufacturing and maintenance costs of progressive cavity pumps are higher. When choosing a pump, there is a trade-off between budget and long-term maintenance costs.

Conveying media: Centrifugal pumps are suitable for conveying a wide range of media, but have limited capacity for highly viscous, gaseous and particulate liquids. Progressive cavity pumps have an advantage in handling these liquids. When choosing a pump, it is necessary to consider the nature of the liquid.

Advantages of centrifugal pumps:

Compact construction.

Wide range Wide range of flow and head.

Suitable for mildly corrosive liquids.

Multiple control options.

The flow is uniform, the operation is stable, and the vibration is small. A foundation that does not require special shock absorption.

The cost of equipment installation, maintenance and overhaul is low.

Centrifugal pumps have major drawbacks:

a. Under normal circumstances, the centrifugal pump needs to be filled or pumped out with a vacuum pump before starting. Although the self-priming centrifugal pump does not need to be filled before starting, there are still limitations in its current use.

b. The viscosity of the liquid has a great influence on the performance of the pump. As the viscosity of the liquid increases, the flow, head, suction lift and efficiency of the pump are significantly reduced.

c. Centrifugal pumps are used in the case of small flow and high head, which is subject to certain limitations. Because the flow channel of the pump body of the small centrifugal pump is very narrow, it is difficult to manufacture, and at the same time, the efficiency is also very low. Although centrifugal pumps have certain disadvantages, they have more advantages, and in many occasions, centrifugal pumps have replaced reciprocating pumps, so centrifugal pumps have gained a wide range of applications.

Advantages of progressive cavity pumps:

1) Wide range of pressure and flow rate. The pressure is about kgf cm2, and the flow rate can reach 100cm3 minutes;

2) A wide range of types and viscosities of liquids to be transported;

3) Because the inertia force of the rotating parts in the pump is low, high speed can be used;

4) Good inhalation performance and self-priming ability;

5) The flow rate is uniform and continuous, the vibration is small, and the noise is low;

6) Compared with other rotary pumps, it is less sensitive to incoming gases and dirt;

7) Solid structure, easy to install and maintain.

The disadvantages of progressive cavity pumps are:

The processing and assembly requirements of the screw are high; The performance of the pump is sensitive to changes in the viscosity of the liquid.

Advantages of centrifugal pumps:

1.Large flow rate, suitable for conveying low viscosity liquids;

2.High pressure, suitable for conveying high-pressure liquids;

3.Stable operation, low noise and low vibration;

4.Simple maintenance, easy to install and repair.

Disadvantages of centrifugal pumps:

1.Not suitable for conveying high viscosity liquids;

2.Flow and pressure decrease as viscosity increases;

3.Not suitable for conveying liquids containing solid particles.

Advantages of progressive cavity pumps:

1.It is suitable for conveying special liquids such as high viscosity, high temperature, high pressure, easy crystallization, volatile, corrosion, and solid particles;

2.The conveying flow is stable, the pressure pulsation is small, the noise is low, and the vibration is small;

3.Easy to maintain, easy to install and repair.

Disadvantages of progressive cavity pumps:

1.The flow rate and pressure are relatively small, and it is not suitable for conveying large flow and high pressure liquids;

2.Relatively high.

Upstairs is just a fool! The screw pump is mainly used to convey some media with high viscosity, with slight pulsation, and the flow rate and stability are not as good as the centrifugal pump! The progressive cavity pump has no shear and does not destroy the molecular force of the medium!

Everyone knows centrifugal pumps, there are chemical centrifugal pumps, water pumps! Hope it helps

1. Screw pump:

Advantages: wide range of pressure and flow, good suction performance, self-priming ability; The flow rate is uniform and continuous, and the vibration is small; Compared to other rotary pumps, they are less sensitive to incoming gases and dirt.

Disadvantages: The processing and assembly requirements of the screw are high, and noise is generated.

2. Gear pump:

Advantages: simple and compact structure, small size, light weight, good manufacturability, cheap and cheap; Easy to maintain and reliable to work.

Disadvantages: The interdental grooves of the end cap and gear form many fixed sealing working cavities, which can only be used as a quantitative pump, and the radial force is unbalanced, the flow artery is large, and the noise is large.

Progressing cavity pumps. The main working part is an eccentric spiroche.

The screw (called the rotor) and the screw bushing with a double helix surface on the inner surface.

called the stator). Its working principle is that when the motor drives the pump shaft to rotate, the screw rotates around its own axis on the one hand, and on the other hand, it rolls along the inner surface of the bushing, thus forming the sealed chamber of the pump. With each revolution of the screw, the liquid in the sealing chamber is advanced by one pitch.

With the continuous rotation of the screw, the liquid is pressed in a spiral pattern from one sealing chamber to another, and finally the pump body is extruded.

The above content reference: Encyclopedia - screw pump.

Progressive cavity pumps: advantages:

1) Wide range of pressure and flow rate.

2) A wide range of types and viscosities of liquids to be transported;

3) Because the inertia force of the rotating parts in the pump is low, high speed can be used;

4) Good inhalation performance and self-priming ability;

5. The flow rate is uniform and continuous, and the vibration is small;

6) Compared with other rotary pumps, it is less sensitive to incoming gases and dirt;

7) Solid structure, easy to install and maintain.

Disadvantages of progressive cavity pumps:

1. The processing and assembly requirements of the screw are high;

2. The performance of the pump is sensitive to the change of viscosity of the liquid;

3. The pump body vibrates violently or produces noise;

Gear pump advantages:

1. Simple and compact structure, small size, light weight, good manufacturability, cheap and cheap; 2. Strong self-priming, insensitive to oil pollution, wide speed range, and able to withstand impact loads; 3. Easy maintenance and reliable work;

Gear pump disadvantages:

1. The intertooth grooves of the end cover and gear form many fixed sealing working cavities, which can only be used as a quantitative pump; 2. The radial force is unbalanced, the flow artery is large, and the noise is large; 3. The efficiency is low, the interchangeability of parts is poor, it is not easy to repair after wear, and it cannot be used as a variable pump;

Nowadays, pneumatic electric diaphragm pumps are used instead of progressive cavity pumps and gear pumps for many applications.

Progressive cavity pumps and gear pumps are common positive displacement pumps that have the following advantages and disadvantages:

1. It is suitable for conveying high-viscosity media and can convey media containing particles.

2. The conveying flow is stable, the pulsation is small, and the output flow is proportional to the speed.

3. It has high self-priming ability.

4. For gas-containing media, the problem of gas-liquid separation can be effectively avoided.

5. Simple structure, easy to maintain and repair.

1. It is not suitable for conveying low-viscosity liquids, and the output pressure is small.

2. For high-temperature media and corrosive media, it is necessary to use corrosion-resistant and high-temperature resistant materials, resulting in high costs.

1. Simple structure, easy to manufacture and maintain.

2. It is suitable for conveying liquids with low to medium viscosity.

3. The conveying flow is stable, and the output flow is proportional to the speed.

4. Small size, light weight, easy to install.

1. It is suitable for conveying low to medium viscosity liquids, and is not suitable for conveying high viscosity liquids.

2. The mechanical seal is easy to be damaged and needs to be replaced frequently.

3. Because the liquid flows through the gear gap, it is easy to leak.

In general, the progressive cavity pump is suitable for high-viscosity media and particle-containing media, with good self-priming capacity and stable conveying flow; Gear pumps are suitable for low to medium viscosity liquids with a simple construction and small volume. Choosing the right pump type requires a comprehensive consideration based on the specific operating conditions and media characteristics.

Advantages of progressive cavity pumps:

1.It is suitable for the transportation of high-viscosity liquids, such as asphalt, lubricating oil, etc.

2.The conveying flow is stable, and the flow rate is proportional to the speed.

3.Low noise, low vibration, low pulsation.

4.Liquids containing solid particles can be conveyed.

Disadvantages of progressive cavity pumps:

1.It cannot convey volatile, flammable and explosive liquids.

2.For less viscous liquids, the efficiency is lower.

3.For highly viscous liquids, leakage is susceptible.

Advantages of gear pumps:

1.It is suitable for conveying low-viscosity liquids, such as water, gasoline, etc.

2.The structure is simple and easy to maintain.

3.The conveying flow rate is large and the pressure is stable.

4.It can convey high-temperature liquids.

Disadvantages of gear pumps:

1.It is noisy and vibrates.

2.For high viscosity liquids, the efficiency is lower.

3.Liquids containing solid particles cannot be conveyed.