Process Pump Solutions for the Pharmaceutical Industry
Care to guess what the most important attribute of process pumps in the pharmaceutical industry is?
There are two broad categories of process pumps on the market today: Rotary pumps, also called positive displacement pumps, and kinetic pumps, also known as centrifugal pumps. There are many variations on these types of pumps, each used for certain applications. Generally, however, a given industry tends to utilize one type of pump over the other.
Centrifugal pumps operate by creating a centrifuge with a piece called the impeller. This forces liquid around the outer border of the pump and sends it through to the discharge tube. Rotary pumps, on the other hand, create a vacuum, suck fluid through the middle of the pump at fixed volume, and then discharge it.
Generally, rotary pumps are best suited for heavier liquids, and centrifugal pumps for lighter liquids. Within the pharmaceutical industry, however, both types of liquids could be present, so the choice of pumps becomes a little more difficult.
Regardless of whether you need a centrifugal or positive displacement pump, cleanliness is absolutely vital. So here are a few things to keep in mind when selecting the right pump for your application:
Centrifugal pumps, ideally, need to be designed with a semi-open impeller with balance holes so that flow is optimized on the back of the impeller. This contributes to high cleanability of the shaft seal as well as the pump itself. The number of product wetted parts needs to be limited. The few parts that are wetted need to be tightly sealed so that there is no room for contaminants to hide. Finally, difficult-to-clean parts of the pump need to be on the outside of where the work happens.
Rotary pumps need to be designed with high rotor nut retention, defined compression front cover sealing, drainable pump head, and clean surface finishes. Another thing to look for is modular design. To meet different process requirements, modular designs – including having an external shaft seal – means the correct shaft seal can be switched depending on the application.
To learn more about pumps for the pharmaceutical industry, or to contact Motion Industries, visit www.motionindustries.com.