What are the performance characteristics of progressive cavity pumps? What are the characteristics o

The performance characteristics of the progressive cavity pump are as follows:

1.High efficiency: The rotor of the progressive cavity pump adopts a special spiral shape, which can generate large pressure and flow rate, improve the pumping efficiency of the pump, and can be suitable for high-viscosity liquids and high-temperature media.

2.Wide applicability: Progressive cavity pumps can convey a variety of media, including high-viscosity, particulate and volatile liquids, etc., which are widely used in chemical, pharmaceutical, food and other fields.

3.Low noise: The structure of the rotor inside the progressive cavity pump is special, and the noise is less when working, and the environmental impact is small.

4.Stability: The unique rotor structure inside the progressive cavity pump can make the liquid flow stable, not easy to pulsate, and provide stable output.

5.Corrosion resistance: The material selection and treatment method of the progressive cavity pump can be customized according to the different media, so as to improve the corrosion resistance of the pump and avoid the corrosive damage of the medium to the pump.

6.Energy-saving: Progressive cavity pumps can save energy consumption and reduce operating costs. Due to the compact structure of the pump, the pump is not easy to produce losses such as liquid volatilization, leakage and shear during the conveying process.

Advantages: 1) Wide range of pressure and flow. The pressure is about 100cm3 min;

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.

Disadvantages: high processing and assembly requirements for screws; The performance of the pump is sensitive to changes in the viscosity of the liquid.

The performance characteristics of progressive cavity pump mainly include the following aspects:

High flow and high pressure: The structure of the progressive cavity pump allows it to produce high pressure and high flow of liquids, such as when conveying oily and viscous liquids, it can effectively maintain the flow and pressure of the conveyed.

Low noise and vibration: Progressive cavity pumps have low noise and vibration compared to other types of pumps, which allows them to be used in environments with high noise and vibration limits.

Good stability: Because the screw pump adopts a twin-screw structure, the change of flow and pressure has little impact on the working state, and the stability is good, and it can adapt to a variety of working conditions.

Low energy consumption: Progressive cavity pumps have low energy consumption and can be adjusted as needed, saving energy and reducing operating costs.

Wide range of application: progressive cavity pump is suitable for conveying all kinds of liquids, including liquids under special conditions such as high viscosity, high temperature, high solid content, etc., and is widely used in petrochemical, pharmaceutical, food and other fields.

In short, the screw pump is characterized by high efficiency, stability, low noise, low vibration, wide range of application, etc., and is a type of pump widely used in the industrial field.

Progressive cavity pumps rely on one or several screws meshing each other to form a constantly changing space volume to transport liquids. According to the number of screws meshing with each other, it can be divided into single screw pump, twin screw pump, triple screw pump and so on. According to the position of the screw, it can be divided into vertical or horizontal.

Among them, the screw pump meshed outside the twin screw pump is composed of a pump body, a driving rod, a driven rod, a gear and a bearing. The driving rod and the driven lever are one left-handed thread and the other is right-handed thread respectively.

The progressive cavity pump relies on the meshing of several screw teeth to form a space volume between the screw teeth to transport liquid when the screw rotates.

The difference between it and the centrifugal pump is the constant volume, that is, the flow rate is basically constant without changing with the outlet pressure, and the difference with the piston pump is that the flow rate is large and the pressure is low.

Applied to chemical and petrochemical fields.

1. Features: 3G three-screw pump is a rotor type positive displacement pump, due to the mutual meshing of the spiral groove on the driven screw and their cooperation with the inner surface of the three-hole bushing, several levels of dynamic sealing chambers can be formed between the inlet and outlet of the pump, and these dynamic sealing chambers will continuously move the liquid from the pump inlet to the pump outlet, and make the liquid pressure increase step by step, so as to form a continuous, stable, axially moving pressure liquid.

2. Applicable medium and performance range:

The liquid conveyed by the three-screw pump is a variety of lubricating liquids that do not contain solid particles, non-corrosive oils and similar oils, and the viscosity of the liquid is high-viscosity liquid, which can also be transported after heating and viscosity reduction. Flow range up to 100 bar and 150 °C max.

3. Structure: 1. Simple structure: with a variety of structural forms, generally small flow, the pump body and bushing of the pump are integrated (collectively referred to as the pump body), and the shaft seal is a mechanical seal.

The pump bushing above the medium flow rate is a single part fixed in the pump body, and the large flow pump is mostly made of double-suction structure horizontal installation, and the shaft seal has two kinds of mechanical seals and packing seals according to the different conveying mediums.

There are two types of marine pumps: horizontal and vertical, and the prime mover is AC and DC marine motors.

2. Long life: The active screw of the three-screw pump is driven by the motor, there is no mechanical contact between the master and slave rods, and the slave rod rotates around the axis line driven by the pressure liquid conveyed, and there is a layer of oil film protection between the master and slave rods, between the screw and the bushing, so the mechanical friction of the pump is very small, and the life can be called semi-permanent.

3. The conveyed liquid moves in the pump at an axial uniform linear speed, so the pressure pulsation is small, the flow is stable, the noise is low, and the starting torque and vibration are very small due to the small inertia of the rotating parts.

4. It has high inhalation capacity.

5. In order to ensure the safety of the pump, motor and pipeline system, the screw pump above medium flow rate is equipped with a safety valve, when the pressure exceeds the set pressure of the safety valve, the high-pressure oil will flow back to the oil inlet of the pump.

The progressive cavity pump is a positive displacement pump, the basic principle of which is to draw the liquid from the inlet into the pump body by the rotation of the screw, and then compress the slamming liquid and advance it along the spiral to the outlet. Progressive cavity pumps usually consist of one or more spiral rotors and a mated fixed housing. The main screw usually has a protrusion that allows the liquid to be drawn into the pump body from one port, compressed and discharged from the other port.

In the rotating process, the bulge of the screw pushes the liquid along the spiral line, and because the gap between the screw and the fixed housing is very small, a high-pressure liquid can be formed.

The performance analysis of progressive cavity pump mainly includes the following aspects:

Flow characteristics: The flow characteristics of the progressive cavity pump refer to the flow changes of the pump under different working conditions. The flow characteristics of the progressive cavity pump are usually relatively stable, because it is a positive displacement pump, and the volume of each rotor is fixed, so within a certain range, the flow rate will not change basically.

Pressure characteristics: The pressure characteristics of the progressive cavity pump refer to the pressure changes of the pump under different working conditions. The pressure characteristics of progressive cavity pumps are usually relatively stable, because it is able to form liquids at high pressures, so within a certain range, the pressure will not change at all.

Efficiency characteristics: The efficiency characteristics of the progressive cavity pump refer to the change of the efficiency of the pump under different working conditions. The efficiency of the progressive cavity pump is usually relatively high, because it is a positive displacement pump, and the volume of each rotor is fixed, so within a certain range, the efficiency will not change basically.

Reliability: The reliability of the progressive cavity pump refers to the operational stability and life of the pump. Progressive cavity pumps generally have high reliability because of their simple structure, stable operation, and easy maintenance.

In a word, progressive cavity pump is a pump with stable performance, high efficiency and strong reliability, which is widely used in various industrial fields.

The advantages can not be replaced by other pumps: 1. The flow rate is stable and pulsation-free, the flow rate is proportional to the speed, and it has metering characteristics; 2. Low shear; 3. Good self-priming performance; 4. Adapt to very low to very high viscosity; 5. Compatible with high solid content and particle-containing working conditions.

The disadvantages are also obvious, and only by understanding can we use them well: 1. Because of the large friction between the stator and rotor, a large torque is required. The efficiency is low, often the shaft absorbs 1kw, and the manufacturer will be equipped with a motor of 3kw or even larger.

2. It is easy to dry grind, high temperature, damage to rubber and other materials of stator, stator and seal are the same consumables. 3. It is often slender and requires a large installation space.

The conveying medium is stable, the discharge medium is low turbulence, the pressure pulsation is weak, the mechanical vibration is small, the noise is low, the self-priming performance is good, the suction performance is good, the working ability of the high speed is not sensitive, the viscosity of the medium is not sensitive, the structure is simple and compact, the size is small, the weight is light, the efficiency is high, the work is reliable, the life is long and the operation and maintenance are convenient.

It is divided into single screw pump, twin screw pump, triple screw pump, and then divided into shaft stainless steel, integral stainless steel, integral stainless steel 304, and integral stainless steel 316 according to the material. There are also motors that are ordinary, explosion-proof, speed regulating and the like.

Single-screw pumps are already obsolete products in foreign countries, with high maintenance costs and high maintenance costs. It is highly polluted to the material medium.

The answers of the two upstairs are already very detailed, I will talk about the use of the screw pump, the single screw pump is very suitable for transporting viscous materials, can allow a small amount of sediment and no more than one lead fiber material, can also transport the medium with corrosive liquid, and can also be used in oil and gas mixed transportation. Twin screw pumps and single screw pumps are mainly used to transport clean media to play a small footprint, energy saving, pressurization, long service life, etc., more in marine pumps, twin screw pumps and filter tanks can also be suitable for a short time of sand-containing working environment.

Abstract:As a kind of water pump, screw pump has many advantages, such as low speed, wide flow channel, small foundation excavation depth, wide pressure and flow range, good suction performance, easy initial installation and maintenance, and is widely used. However, it also has disadvantages such as large size, low head, high processing and assembly requirements, etc., which need to be paid attention to when using. The core components of the screw pump are the stator and the rotor, during the working process, the medium will wear them, so the durability is limited, the screw pump produced by a good manufacturer, pay attention to the case of controlling the speed according to the conveying medium, the screw pump is still relatively durable.

Let's take a look at the advantages and disadvantages of progressive cavity pumps. First, the advantages and disadvantages of screw pump.

Screw pump is a commonly used water pump, composed of shaft, spiral blades, shell, mostly used for irrigation, drainage, and lifting sewage, sludge and other occasions, this kind of pump has both advantages and disadvantages:

a) 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.

5. Wide range of pressure and flow.

6. A wide range of types and viscosities of liquids to be transported.

7. Good inhalation performance and self-priming ability.

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

9. Compared with other pumps, it is less sensitive to incoming gases and dirt.

10. The structure is solid, and the installation and maintenance are easy.

2) 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 outlet surface should not change too much, otherwise it will affect the work efficiency and increase the energy consumption.

4. The processing and assembly requirements of the screw are high.

5. The performance of dry screw pump is sensitive to the change of viscosity of liquid.

6. The pump body vibrates violently or produces noise.

Second, is the screw pump durable?

As a kind of water pump, the advantages and disadvantages of the progressive cavity pump are obvious, and everyone may be more concerned about the durability of the progressive cavity pump, so is the progressive cavity pump durable?

Generally speaking, the core components of the progressive cavity pump are the stator and the rotor and the permeable bar, which will inevitably cause wear and tear to the stator in the process of conveying the medium, so its durability is limited. In fact, the service life of the screw pump is mainly related to the manufacturing process and actual use, and the plex lead screw pump produced by a good manufacturer is definitely more durable.

Of course, in addition to the quality of the product, the durability of the progressive cavity pump also depends on the medium it transports, the larger the viscosity and particles of the conveyed medium, the greater the wear of the stator. Conversely, if only clean water or mild sewage is delivered, the service life will be longer. In practical use, in order to reduce the wear of the medium on the stator and prolong the service life of the progressive cavity pump, it is recommended to adjust the corresponding speed according to the characteristics of different media.

The advantages of progressive cavity pumps include:

When conveying the medium, there is no eddy current, circulation and dead angle, the flow is uniform and continuous, the adaptability to the medium is strong, and the energy-saving effect is good.

It has good sealing performance and can pump out gases, liquids, solids, solid-liquid mixtures and media containing suspended solids.

High speed, strong self-priming ability, idling, axial and radial blocking force is small.

Compact structure, easy to install and maintain.

Small size and light weight.

The disadvantages of progressive cavity pumps include:

Difficult for media with viscosity of more than 100 centipoise.

The particulate material should be filtered to prevent clogging of the pipeline.

Gases, solids, mixtures of liquids, and liquids containing dissolved solids cannot be pumped.

Gases, volatile liquids, and liquids that are too light or too heavy cannot be pumped.

When the speed is reduced or the displacement of the socks is reduced, the progressive cavity pump may become clogged.

The inhalation performance is poor, and it is not suitable for pumping liquid residual body with viscosity lower than that and liquid containing impurities in the free state at room temperature.