centrifugal pump advantages and disadvantages

A Guide for Progressive Cavity Slurry Pump

What is Progressive Cavity Slurry Pump?

A PC pump or progressive cavity slurry pump is a type of positive displacement used for highly viscous fluids. While it is a versatile pump capable of many applications, it is particularly well-suited for pumping viscous, abrasive, or shear-sensitive materials and metering chemicals. Progressive cavity pumps are also known as advancing cavity pumps, PC pumps, cavity pumps, and prog cavities.

Work in Flow of Progressive Cavity Slurry Pump

PC or Progressive Pump is the one that is in charge of generating flow. The compression supports the moving liquid structure at the tip of the nozzle.

PC pumps or Progressive Pumps suck fluid into an extended casing by a suction intake. A helical commutator assembly is encased inside the house building. The stator helix is offset from the rotor helix as the rotor revolves and makes contact with the stator’s surface—a sequence of tiny cavities forms.

The fluid “progresses” through these cavities, eventually exiting through a discharge outlet.

PC pumps or Progressive Pumps can sometimes run out of water because the heat generated by the stator and the rotor can end up causing the compressor to screw up. Several PC pumps have accessories that protect them from this.

The progressive cavity or PC pumps have higher phase force than most positive displacement pumps and a high pumping lift.

Progressive cavity pumps transport fluids that other industrial pumps cannot. They usually provide the following functions.

• Chemical pumping
• Shear-sensitive materials are being pumped.
• Pumping abrasive-particle-containing materials
• Pumping viscous or heavy fluids

Trying to pump, Dosage forms and Meter reading Chemicals

The cavities inside a PC pump tip coincide at their edges. And so there is no flow vibrating other than that produced by the pump portion or liquid deformation. This steady, low-pulsation pumping makes PC pumps ideal for metering applications.

PC pumps have a flow rate proportionate to their speed, allowing them to administer highly viscous fluids such as additives and chemicals.

Pouring Slenderness Components

A PC pump’s volumetric flow rate is related to its rotation rate. The pumped fluid is subjected to relatively minimal shear due to this. Because of this property and reduced internal velocity, PC pumps are appropriate for pumping shear-sensitive materials, such as fluids containing delicate solids.

Pumping Products contain Abrasive Granules.

Fluids flow at high speeds around the interior walls of the casing in other pump designs. When abrasive solids in the pumped material, they “scour” the pump’s surfaces, causing it to wear out before its useful life is up.

In contrast, it moves fluid via a lengthy casing. Instead of being impacted centrifugally, the abrasive particles travel parallel to the inside surfaces at a reduced speed.

PC pumps are much more durable when used for these application areas and last longer than others.

Trying to pump Large or Shear thickening Fluids.

Progressive cavity pumps are ideal for pumping more excellent viscosity fluids. The flow rate of a centrifugal pump decreases as the fluid viscosity increases. This is inefficient since the pump must raise its energy usage to keep up.

PC pumps, like all positive displacement pumps, generate their flow. A PC pump or Pump Cavity has become better and more efficient as viscous grows and will have approximately the same flow velocity despite the weight of the compelled techniques.

Pumping Fluids in Applications With Varying Flow Rates

PC pumps generate a precise flow every revolution, making it simple to govern the flow by adjusting the pump speed. They work effectively in conjunction with variable frequency drives to manage flow rates.

Similarly, PC pumps or progressive cavities can sometimes be utilized when a constant flow is required, but the viscosity of the pumped fluid varies.

Features of Progressive Cavity Slurry Pump

A Drawbar is Short if Needed at All

Progressive cavity pumps are built without or with a short drawbar if necessary. The reduced or deleted drawbar simplifies stator installation and removal compared to standard pumps.

Double-layer Sealed Sheath

Double-layer sealed sheath outperforms single-layer sealed sheaths in wear resistance and has a longer service life. The outer sheath can prevent lubricant from leaking and polluting the media contents while the inner sheath is disabled.

Ball-tooth Universal Joint

When bearing axial load, this ball-tooth universal joint can generate more torque, and its overall shape makes it easier to disassemble and install.

Cross-pin Universal Joint

Cross pin universal joint is used for bigger multilayer progressive cavity pumps. It is lubricated with grease and thin oil to withstand high torque and axial forces.

Application of Progressive Cavity Slurry Pump

As shown in the illustration, the suitable, progressing cavity pumps are distinguished by their extended, thin architecture, with the stator being nearly ten times as wide as it is. This means that much room is often required within the installation, which can be a disadvantage. Models with a more compact design are available. However, this usually comes at the expense of the maximum pressure they can work at.

Progressive cavity pumps are utilized in a variety of applications, some of which are:

• dosage and metering
• wastewater
• manufacture of chemicals
• petroleum extraction/production
• processing of food and beverages
• paper and pulp
• environmental engineering
• Pump well water with low energy
• Pumping of lubricant oil

Progressive cavity pumps must be carefully selected for the temperature of the fluid and are not a good solution where temperatures vary greatly. The stator and helical rotor may only have a few millimeters of clearance to make the pump efficient and transfer fluids at the desired flow rate. Because the stator is made of rubber, significant temperature fluctuations can cause a slight swelling, resulting in a difference in efficiency, flow rate, and pressure. Eccentric screw pumps are typically sized to the requested flow and pressure at a specific temperature, and if this changes, the pump may still function but at a reduced efficiency.

Operating Principle of Progressive Cavity Pumps

Progressive cavity pumps are rotating positive displacement pumps that handle liquids by first transporting them into a conveying chamber and then displacing them from there. The transporting movement is propelled by a rotating shaft (in contrast to the reciprocating pump, where the piston runs straight).

The rotor, or rotating shaft, oscillates against a stationary stator because of the two components’ rotating spiral geometry. Conveying chambers (also known as cavities) are formed where the medium from the pump flows intake to the pump output.

While the rotor is constructed of a relatively rigid material (generally metal, but ceramic is also used in particular applications), the stator is elastic and is typically formed of an elastomer.

The flow rate of progressive cavity pumps is unaffected by the consistency and viscosity of the fluid handled: the quantity delivered is dictated only by the speed. Pump capacity may be precisely regulated when combined with a frequency converter.

A five to three percent precision is possible; small dispensers can achieve one percent. For media holding high amounts of dry material, funnel pumps with specific screw conveyors and so-called bridge breakers are appropriate.

The medium is tamped with a conical tamping area and a transfer screw for maximum product supply. Spoked wheels that reliably act on the medium prevent bridge building in the pump shaft.

Benefits of Progressive Cavity Pumps

The progressing cavity pump’s conveying principle has several benefits:

• Continuous, low-pulsation handling of even high-viscosity liquids: The rotor’s steady rotation prevents abrupt pressure fluctuations.
• Gentle media management with a high solid content: The conveying gap between the rotor and stator has only low shear forces.
• Excellent dosing precision: For progressive cavity pumps, the pump capacity may be determined precisely based on the speed.
• Simple direction reversal and direction are conveying.
• High suction capabilities even when the gas content is high (up to 9 times)
• Significant free ball passage: A large allowable diameter for solids minimizes clogging.
• Because of the long service life and maintenance intervals, the life-cycle costs are low.

Other benefits:

• It could operate with light, cross, and abrasive liquids.
• Tailored to low – and high-application areas
• Allows continuous, reasonable flow rate.
• Self-priming
• It doesn’t evaporate into the air
• High pumping strength
• The lateral system operates.
• Quiet

The Disadvantage of (PC) Progressive Cavity Pumps

• A fluid film is bound to maintain the dragging (contacting) surfaces lubricated. Once they run dry, such pumps fail.
• Progressive cavity pumps move slightly quicker and only create a slight fluid motion. It can be fixed using VFDs (variable frequency drives) and suppressants, which raise installation costs. A VFD may be a complex, specific application.
• The pump’s flow rate suffers when viscous fluid doesn’t flow rapidly into the compressor. This implies that the speed limits for the stipulated liquid and viscous are essential (and therefore should be thoroughly checked and firmly attached to) (and should be carefully checked and adhered to).
• PC pumps can only pump a certain level of liquid.
• Due to the apparent rotor/stator fittings, slowdown rates might be substantial, starting to cause the pump to be ineffective.