Sealing Mixers and Agitators

According to a recent Pumps & Systems magazine article authored by Terry Roberts and Zach Nepa, air seals are key in preventing powder and slurry leakage in safety-focused and harsh industries. This includes sealing mixers and agitators

Product Leakage and Shaft Movement in Agitators and Mixers

Large bottom- or side-entry mixers and agitators, often used in paper and food production, are difficult to seal. Sealing mixers and agitators is difficult because the shaft enters through the bottom or side of the equipment. Leakage is virtually guaranteed over time and use.

But when it comes to food and paper production, shaft movement is another issue.

“In both process industries, large amounts of ingredients may be dropped into the equipment causing the shaft to move and vibrate,” the Pumps & Systems article says. “This movement may damage packing and mechanical seals. This [causes] to downtime to replace the seal, only to restart the cycle of wear, damage, leakage and replacement once the asset is restarted.”

So, how can plants and reliability teams end this cycle? This is where air seals can help.

How Do Air Seals Increase Equipment Reliability?

Air seals do not contact the shaft or sleeve. They accommodate misalignment that may occur when heavy ingredients and materials drop into the bowl.

“Packing may fret the shaft or sleeve and create leakage paths,” the article explains. “Mechanical seals may be damaged by the shaft movement and allow leaks. Eventually, the product is no longer sealed, and it ends up on the floor.”

To remedy this problem, air seals have been used in dry and wet applications, including hydrapulpers, agitators, mixers and blenders.

Air seals improve operations within many industries, namely pulp and paper and food and beverage. In one case, air seal technology prevented dough ooze and bacterial growth at an East Coast animal cracker producer. In another at a Midwest paper mill, an air seal eliminated pulp leakage, as well as the need for packing replacement, costly downtime, and gearbox maintenance.

Read the complete article on!

About the Author
Anna Claire Howard is a contributing writer, editor, and content marketing specialist for Sealing Equipment Products Co. Inc. (SEPCO) and has been since Spring 2019. Before those two big life changes, she was the content marketing specialist for Fluke Accelix; assistant editor for Grand View Outdoors, publisher of Bowhunting World, Predator Xtreme, Whitetail Journal, Tactical Retailer, and Shooting Sports Retailer; managing editor for Media Solutions, Inc., publisher of Gear Solutions, Wind Systems, and Thermal Processing magazines; assistant editor for MSI; and the editorial intern for B.A.S.S., LLC, publisher of Bassmaster Magazine and In these B2B/B2C roles, Anna Claire developed an appreciation for the industrial sector, as well as the operators and technicians who make up the workforce. You can find her on LinkedIn at