The Top 4 Pumps Found in the Chemical Industry

Common pumps found within the chemical industry and how a Pump can be a better solution for many applications.

Pumps are the workhorses of industry and are used in many different applications in a wide range of industries. These include the oil and gas, petrochemical, food & beverage, and chemical processing industries.

Operators in these industries have a wide range of pumps to choose from. Many of the popular types of pumps are adequate for most applications in the chemical industry. However, sometimes pumps need to work under extremely harsh conditions, especially when liquids contain solids and fibrous material that make them difficult to pump.

Considerations for Pump Selection

Many different types of pumps are used in the chemical processing industry. Pump selection depends on the characteristics of the liquid to be handled, which include viscosity, corrosiveness, and abrasiveness. Liquid-gas mixtures need pumps that will handle them efficiently without causing production stoppages or pump breakdowns. Liquids containing large amounts of solid material require robust pumps designed to withstand harsh conditions and to transport these mixtures effectively.
Liquid characteristics also play a critical role in selecting materials of construction for pumps. Corrosion is a major consideration in the chemical industry, and the material used in pump construction must be compatible with the medium to be pumped. For instance, highly corrosive liquids like acids require the use of stainless steel in pump construction.

The main types of pump used in the chemical industry are:

Centrifugal pumps:

These are the most common type of pump used in the chemical industry. They are highly efficient pumps, simple in design and operation, and generally less expensive than other types of pumps.

All centrifugal pumps draw liquid into the impeller by suction, causing a vacuum. This feature of the centrifugal pump also makes it prone to cavitation, especially with low intake pressures. A major disadvantage of the centrifugal pump is that it has poor suction power and needs to be primed to start pumping.

Positive displacement pumps:

These are all types of rotary pumps and include gear, screw, and rotary vane and piston pumps. They are more efficient than centrifugal pumps at moving high viscosity fluids and can deliver high pump pressures. Positive displacement pumps can also move low vapour pressure fluids, which flow at lower speeds and create more resistance.

Diaphragm pumps:

These pumps are also a type of positive displacement pump and move liquids or liquid-gas mixtures via a reciprocating diaphragm. They have a number of advantages over other types of positive displacement pumps. Firstly, they do not have any internal wear components, which reduces maintenance considerably. They also require no sealing or lubrication, which eliminates the risk of oil vapour leakage and contamination of the process fluid.

Turbine pumps:

These pumps have turbine-like impellers with radially oriented teeth to move the liquid. Turbine pumps combine the versatility of a centrifugal pump with the high discharge pressures of positive displacement pumps. However, they are not suitable for the transport of liquids with solid content.

There are literally thousands of pumps on the market that fall within these categories and perform admirably under most circumstances. However, many of them also have serious limitations when it comes to handling highly corrosive or abrasive fluids, or liquids with high solids content, like slurries.