February 11, 2025
Categories: Blog

What is progressive cavity pump and what is it used for?

At Dispense Robots, we specialize in progressive cavity pumps (PC pumps), also known as screw pumps, which are widely used across various industries for transferring and dispensing medium to high viscosity materials. These pumps provide a consistent flow and withstand high temperatures, making them ideal for handling oils, cosmetics, paints, adhesives, and other abrasive or corrosive substances.

However, while PC pumps offer several advantages, they also come with limitations. Their compatibility with certain fluids is restricted, and their intricate mechanical seals require regular maintenance, leading to higher operational costs.

The pumping rate is very constant and linear at various pressures since the pump’s output volume and speed are exactly proportionate. Progressive cavity pumps provide one of the greatest flow and pressure combinations achievable from positive displacement pumps, with capacities of up to 600 m³/h and pressures of up to 48 bar. These pumps can handle fluids with viscosities more than 5 CST because of their 55%–75% efficiency range. They are therefore appropriate for a variety of industrial applications.

How does a Progressive Cavity Pump work?

A progressive cavity pump can run at lower RPMs than centrifugal pumps with the same horsepower because it combines a motor and gearbox. A rotor that revolves inside a stator is powered by a gearbox. While the stator is composed of a rubbery substance, the rotor is typically metallic in nature. By moving inside the stator, the rotor creates a series of chambers that enable the fluid to pass through the pump steadily and slowly.

Pressure is produced by each rotor cavity, and high pressure systems usually employ a large number of rotors and stators. Up to 6 bar of pressure can be produced by each rotor, and when several rotors are utilized, pressures can rise to 48 bar. The fluid being pushed must serve as lubrication because of the little space between the rotor and stator. Any changes in temperature have the potential to cause the stator to expand, which could result in damage or slicing when it contacts the rotor. Progressive cavity pumps work well for moving lubricating fluids that are viscous and may contain particles. But corrosive fluids may shorten the stator’s lifespan, therefore for some applications, the peristaltic pump is a superior choice.

Parts of Progressive Cavity Pump

Rotor: The main rotating part of a machine is usually composed of hardened metals, tool steel, stainless steel, or cast iron. The fluid passes through the pump by the cavities created by the rotor’s distinctive circular shape.
Stator: The pump is not suitable for liquids based on solvents since the stator is made up of elastomer substances, such as NBR or FKM, instead of PTFE. It is possible to create stator sides with equal or dissimilar thickness. Equal-walled stators are devices that use less energy and produce less torque and vibration.
Universal Pin Joint: This allows the rotor to spin irregularly within the stator by joining it to the drive shaft.
Gearbox: Allows the pump to operate at the lowest possible RPMs necessary. Discover how our advanced progressive cavity pumps integrate these components for optimal performance.”

Progressive Cavity Pump Applications

Because of their versatility, progressive cavity pumps from Dispense Robots are used in many different industries. Some of the primary uses are as follows:

Wastewater Treatment: Because they are utilized for polymer dosing and the transport of bulkier, processed waste, these pumps are essential in water treatment plants.
Oil & Gas: Cutting, separation supply, multiphase, drilling mud, and crude oil extraction transfers are all common applications for progressive cavity pumps. Additionally, they are ideal for injecting fluid at remote oil fields.

Biogas: Biomass and digested matter are commonly moved in biogas producing plants to guarantee efficient operation.
Pulp and Paper: In paper mills, these pumps are used to transfer pulp, recycled paper, fillers, and colors.
Edible Oils: Progressive cavity pumps are appropriate for processes like oil extraction, oil extraction, filter press feed, and oil separator feed.
Wine Production: Vintners rely on progressive cavity pumps to move must and trash, press grapes, and filter their wine.

Dispense Robotics Progressive Cavity Pumps Benefits

Low Pulsating Flow: Due to their low RPM rotation, these pumps have a smooth, minimal pulsating flow. The uniform wall design of the stator and the long-pitch rotor further reduce flow pulsation.
Low Shear Handling: Progressive cavity pumps are particularly good at handling fluids such as oil and water mixes, resins, and sticky foods. For industries like the oil and gas sector, its capacity to handle these fluids without altering their consistency is a vital advantage.
Reversible Operation: These pumps can be used to drain hoses and clear obstacles by operating in reverse. This capacity makes them appropriate for tanker loading and unloading operations.

Wide Variety of Fluid Handling Capabilities Progressive cavity pumps can handle a wide range of fluid types, including fibrous solids, gas slugs, large solids, viscous liquids, and abrasive materials. When it comes to viscosities between 1 cst and 1 million cst, they excel.
Self-Priming: The pump’s strong suction capabilities, which are enabled by exact tolerances in its design, allow it to self-prime up to eight meters.
High Accuracy: Because the pump’s flow rate is precisely proportional to its speed, it is perfect for precise measuring and dosing applications.

High Flow and Pressure: Progressive cavity pumps, one of the strongest positive displacement pumps available, can produce pressures of up to 48 bar and flow rates of up to 600 m³/h. It is commonly known that because of their non-clog design, these pumps can handle sticky mud without choking. In the event that clogging does develop, they include wide inspection ports that make it easy to perform an inside inspection without having to disengage from the pipes.

Model Variants

Dispense Robotics offers a range of progressive cavity pump designs to cater to different industrial needs:

Hopper Pumps

These pumps come with hoppers that handle materials with high dry content, such as viscous liquids and large solids. Auger screws or paddles are often used to aid material flow into the
pump.

Food-Grade Pumps

Designed for hygienic applications, these models comply with 3A and EHEDG standards for easy cleaning. They can be mounted on trolleys for mobility.

Macerator Pumps

Featuring inline grinders to break down solids before they enter the pump, these models are ideal for industries that deal with solid-laden fluids.

Vertical Immersion Pumps

These pumps are designed to be submerged in fluids, eliminating NPSH issues. They are suitable for open or closed drain applications.

Multiphase Pumps

Capable of handling viscous oil, gas slugs, sand, and water, these pumps are perfect for multiphase boosting applications.

Wobble Pumps

These smaller pumps feature a single joint design, which causes the rotor to wobble instead of rotating in a full circle, making them ideal for certain niche applications.

Pump curve

The linear nature of pump curves, as opposed to centrifugal curves, indicates the unit’s ability to handle liquids with a range of viscosities with little impact on pump performance. Furthermore, because flow is related to speed, speed serves as the bottom axis rather than flow. Compared to centrifugal, unit speed can run as low as 50 rpm, which is far lower.