The progressive cavity pump is a versatile pump that is used across different industries. It is specially designed to handle highly abrasive fluids. In this guide, let’s take a closer look at the working of a progressive cavity pump, features, and benefits.
What is a Progressive Cavity Pump?
The progressive cavity pump is a type of displacement pump. It’s highly versatile and flexible and best suited for toughest pumping applications, handling highly viscous liquids. It can handle a wide array of jobs like pumping viscous, shear-sensitive, and abrasive materials. Other terms for progressive cavity pumps are – cavity pumps, progg cavity pumps, and PC pumps.
How does a Progressive Cavity Pump work?
Just like other positive displacement pumps, a progressive cavity pump is a flow-creating device. It moves the displaced fluid at a constant speed, regardless of the inlet pressure.
It draws the fluid via the suction inlet and transports it into an elongated casing. Inside the casing are housed a helical rotor and stator. As the rotor turns, it touches the surface of the stator, leading to small cavities formation. The fluid then flows progressively through these series of cavities, until it is expelled via a discharge outlet.
The positive displacement pump cannot be run dry. If run dry, the heat generated between the rotor and stator leads to pump failure. Most PC pumps have safeguard mechanisms that prevent it from running dry.
Applications that require a Progressive Cavity Pump
Progressive cavity pumps are mostly used for:
Wastewater treatment plants
Sewage, slurry and sludge pumping
Metering and dosing
Pulp and paper processing
Food and beverage processing
Cement or grout pumping
Lubrication oil pumping
Salient Features of a Progressive Cavity Pump
The high suction capacity of up to 9mWC
It can be installed in any orientation
The direction of flow can be reversed
It runs quietly and smoothly with minimal pulsation
It can operate in temperatures ranging from -20◦C to +200◦C
Benefits of a Progressive Cavity Pump
Higher discharge pressure
High suction capacity
Continuous and low pulsation flow
A flow that is proportionate to the speed
Reverse flow and rotation
Low life-cycle costs due to minimal downtime and failure
When to use Progressive Cavity Pumps?
#1: For Dosing and Metering Applications
The smooth, low pulsation produced in a progressive cavity pump makes it ideal for metering applications. Since the flow rate of a PC pump is proportional to the speed, it can be used to dose viscous fluids like chemicals and additives.
#2: For Pumping Shear-sensitive Materials
The volumetric flow of a PC pump is proportional to the rate of rotation. As a result, the pump applies minimal shear to the displaced fluid. This makes it suitable for pumping fluids that hold fragile solids.
#3: For Pumping Fluids with Suspended Abrasive Materials
In other pump designs like a centrifugal pump, the fluid hits the inside walls of the casing at high speeds. As a result, the abrasive solids damage the pump’s surface, causing wear and tear.
In a progressive cavity pump, the fluid flows through the pump parallel to the internal surfaces. As a result, a PC pump is long-lasting and abrasion-resistant, making it best suitable for applications that transport abrasive fluids.
#4: For Transporting Fluids with High Viscosity
In a centrifugal pump, the flow rate drops as the fluid viscosity increases. This makes it less efficient when handling fluids with high viscosity. On the other hand, a PC pump is more efficient as viscosity increases.
#5: For Applications that Require a Precise Flow
A positive displacement pump produces a precise flow per revolution when used along with a VFD (Variable Flow Drive). Hence, it’s ideal for applications that require a steady stream.
Why choose a Progressive Cavity Pump instead of a Centrifugal Pump?
A progressive cavity pump is a type of positive displacement pump. It operates differently compared to centrifugal pumps, the most commonly used industrial pump. Generally, centrifugal pumps are chosen for their cost-efficiency and reliability. It pumps fluids with low viscosity like water at a fixed flow and constant discharge. A well-built centrifugal pump can last for years.
However, there are several applications where a centrifugal pump cannot be used. For example, a centrifugal pump cannot handle liquids with high viscosity like slurries. In such scenarios, a centrifugal pump becomes volumetrically and mechanically inefficient. When the fluid’s viscosity goes up, the output flow goes down, and power consumption increases in a centrifugal pump.
However, in the case of a progressive cavity pump, the pump’s efficiency increases when handling highly viscous liquids. With lower power, the pump can produce a more substantial flow.
Here are some scenarios where the progressive cavity pump is a better choice than centrifugal pumps:
A progressive cavity pump is ideal for liquids with higher viscosity.
It’s also ideal for applications that require a constant flow.
When used with a VFD (Variable Frequency Drive), it can also be used for applications that require a varied flow. You can regulate the output flow just by adjusting the pump operational speed.
The progressive cavity pump is suitable for applications where the suction conditions are not ideal.
Ideal for transporting liquids that contain abrasive solids.
If you need a progressive cavity pump for your application, let the experts at Sintech help you find the best pump for your needs. Our pumps and parts are manufactured in India and exported worldwide to various countries like the US, EU, South Americana, and several more. Get in touch with our team to find the best pump for you.