Progressive Cavity Pump

Progressive cavity pumps, also known as PC pumps and single screw pumps, are positive displacement pumps. With a wide range of industrial applications, it can transport almost any substance continuously, at a constant pressure, gently and with low pulsation. Whether it is wastewater sludge, chemicals, slurries, adhesives, oil or shear-thinning non-Newtonian fluids.

AOBL is a professional manufacturer of progressive cavity pumps and offers a wide range of PC pumps including conventional, open hopper type, dosing type and stainless steel food grade. With a wide range of rotor/stator geometries and a variety of engineered fittings in the right combination to meet your application requirements, AOBL progressive cavity pumps are cost-effective and low-maintenance, and are available in a wide range of sizes and materials, with flow rates from 0.3 m³/h up to 150 m³/h.

Eccentric Screw Pump

Conventional single screw pumps with competitive pricing. It has a small footprint for tight installation spaces and is available in low to high flow configurations.

Open Hopper Screw Pump

Cake pumps with open hoppers are used for conveying and handling materials containing high percentages of solids or abrasive materials.

Progressive Cavity Metering Pump

Used as a dosing metering pump for chemical dosing in wastewater treatment. Commonly used in sludge dewatering and thickening processes.

Food Grade Progressive Cavity Pump

Food hygienic screw pumps are suitable for products in food, pharmaceutical, cosmetic and other industries with high hygiene requirements.

Design and working principle of progressive cavity pumps

The design of progressive cavity screw pump is simple and compact. It mainly consists of pump casing, screw, bearings, seals and transmission device. The pump casing is usually made of cast iron or stainless steel with good sealing. The screw is in the shape of a single helix and forms a sealing working chamber by cooperating with the inner surface of the pump casing. The screw is usually made of stainless steel or hard alloy with high wear and corrosion resistance. Bearings are used to support and position the screw to ensure its proper operation. The selection of seals is very important to ensure the sealing performance and working efficiency of the pump. The drive can be a motor, gearbox or other transmission device for driving the rotation of the screw.

Structural Diagram of Progressive Cavity Pump 1

The operating principle of a progressive cavity pump is based on a cam motion between the screw and the pump casing. Inside the pump casing there is a spiral groove, while the screw is responsible for rotating and moving inside the spiral groove. As the screw rotates, the liquid is drawn into the spiral groove and gradually pushed forward as the screw rotates. During this process, the liquid is restricted by the spiral groove and pushed by the cam, forming a sealed working chamber. As the screw continues to rotate, this sealed working chamber will gradually move forward along the helix, discharging the liquid from the inlet to the outlet.

Structural Diagram of Progressive Cavity Pump 2

progressive cavity pump usage

Single screw pump outlet rated pressure can be increased with the increase in the number of pump stages, each additional level, the pressure increased by 0.6MPa, so the application range is very wide.

Environmental protection: industrial sewage, domestic sewage, sludge containing solid particles and short fibers turbid water transport. Especially suitable for plate and frame filter press and other equipment.
Shipbuilding industry: wheel bottom cleaning, oil and water, oil sludge, oil sewage and other media transportation.
Petroleum industry: conveying crude oil, the use of screw pumps to the formation of polymer injection to increase the recovery rate of oil fields.
Pharmaceuticals, daily chemical: a variety of viscous slurry, emulsion, various ointments and cosmetics, such as transport.
Food canning industry: all kinds of viscous starch, cooking oil, honey, syrup, fruit syrup, cream, minced fish and minced meat and its scraps of transportation.
Brewing industry: a variety of fermentation viscous liquid, thick wine lees, grain product residue, various sauces, pulp and viscous liquid containing lumpy solids transportation.
Construction industry: cement mortar, lime slurry, paint and other paste spraying and transportation.
Mining industry: sewage and slurry water containing solid particles in the mine are discharged to the ground.
Chemical industry: transportation of various suspensions, grease, colloidal slurry and adhesives.

progressive cavity pump parts

The main parts of progressive cavity pump include discharge chamber, rotor, stator, universal joint, intermediate shaft, suction chamber, shaft seal, bearing housing assembly, etc.

Rotor: according to the media characteristics, there are a variety of materials to choose from (304, 316L)
Stator: the stator rubber sleeve material can be selected from a variety of rubber materials such as nitrile rubber, fluorine rubber, EPDM rubber, super abrasion-resistant rubber, food-grade rubber, etc., which is able to meet a variety of abrasive, corrosive, high-temperature and other harsh working conditions.
Universal joints: rubber sheath on the outside, grease lubrication on the inside, national standard cross shaft structure, high transmission torque, high reliability, long life, easy maintenance.
Shaft seal: packing seal, single-end mechanical seal, double-end mechanical seal and other sealing methods, and packing seal and single-end mechanical seal can be interchanged.
Inlet chamber and outlet short connection: there are various materials for choice, and the inlet chamber can realize the direction of upward, leftward and rightward interchangeable, the installation mode is more flexible.
Bearing housing or support frame: when the reducer and pump are connected by coupling, the bearing housing structure is adopted; when the reducer and pump are directly connected, the support frame structure is used.

progressive cavity pump advantages and disadvantages

advantages

Continuous and low pulsation conveying, not affected by pressure and viscosity fluctuation.
Wide range of applications, can transport flowing or even non-flowing materials.
The medium in the pumping process will not be stirred, free from extrusion and shear.
High efficiency, the conveying capacity is proportional to the rotating speed, and the conveying capacity can be adjusted by frequency conversion.
Most of the liquids can be pumped under small agitation and pulsation.
Easy maintenance and repair, with high pressure conveying capacity.

disadvantages

The processing and assembly requirements of the screw are high, and the performance of the pump is sensitive to changes in the viscosity of the liquid.
Stators made of rubber and other materials have a short service life, and vibration will be louder than other pump vibration sounds.

FAQ

When the progressive cavity pump works, the rotor and the stator are in contact with each other, and there is relative slip, so the efficiency of the single screw pump is generally 65% to 80% of the speed. The screw pump with larger liquid discharge per revolution has higher efficiency.

1 mPa.s – 1060 mPa.s

In general, the larger the flow, the larger the size. At the same time, the solid containing fluid must have sufficient cavity size to pass through the largest hard particles in the product.

Transport lubricating oil, transport fuel oil, transport each kind of oil and polymer, practical for transporting thick liquid.
Transport medium with high viscosity: according to the size of the pump, the viscosity of the medium can be transported from 37,000 to 200,000 centipoisons.
Transport media containing particles or fibers: the particle diameter is 30 mm, not exceeding the rotor eccentricity. The fiber length is 350 mm, equivalent to the pitch of a 0.4 position rotor. Its content can usually reach 40% of the medium cellar, if the solid matter in the medium is small powder, the maximum content can reach 60% or more can also be transported.
When the transport pressure is required to be stable and the medium has no structural damage.

Generally between 0.6MPa and 2.4MPa, it can also be customized according to actual needs.

The performance of ordinary pumps is poor when transporting high-viscosity media, and the use of progressive cavity pumps is the best solution.

Check flange bolt connection and thread connection
Check the pump protection device
Check whether the power supply in the control cabinet is turned on and whether the connection points of electrical components and lines are firm
Check whether the inlet and outlet are open
Check whether there are foreign bodies around and clean them up in time, mainly in the rotating parts and surfaces
Check the electrical connection/hydraulic connection
Check whether the rotation direction is consistent with the direction indication

There are three main types of screw pumps

Archimedes screw pumps, in which a single screw rotates in a cylindrical cavity, thereby trapping some material on top of the screw part by gravity, as if it were a spoon, and gradually moving the screw material to flow along the screw shaft until the top is discharged. This ancient building is still used for many low-tech applications, such as irrigation systems and agricultural machinery for transporting grain and other solids.

Screw pump, It squeezes the trapped bag of material onto the other screw. This form is commonly referred to as the “screw pump” in modern times.

Eccentric screw pump squeezes the residual material onto the cavity wall by rotating the eccentric screw.

Although there are many kinds of screw pumps, the common denominator is that they all belong to positive displacement pumps.

German Netsch company is the world’s first single screw pump inventor, Warren is located in Massachusetts, the United States, in 1890 invented the world’s first double screw pump. Houttuin, based in the Netherlands, invented Europe’s first double screw pump in 1929. The three-screw pump was invented and manufactured in 1931 by the Swedish IMO company, and Baumann, with a history of 153 years, designed and manufactured the world’s first external bearing double-screw pump in 1934.