Case Study: Rotary Airlock in Sugar

Meyer Valves and Feeders

Otis Spunkmeyer Bakery, located in Illinois, produces gourmet cookies and ready-to-bake bread dough. They originally started as a cookie manufacturer but have become the leading producer of contract baked goods for retailers and restaurants. They are committed to making better products with fewer ingredients and none of the “funky stuff”.

The Problem

The Bakery had a previously installed a rotary airlock in sugar with large “chunk” pieces. This caused the valve to jam and would result in frequent downtime. The constant failures became a maintenance nightmare. Jim Lierow, maintenance manager, reached out to Meyer looking for a solution. His goal was to eliminate his reliability issues with the production line. Jim has had over 34 years of experience using rotary airlock valves at other companies such as Purina and Chobani.

Rotary Airlock Valve with Sugar

Process Specifications

The rotary airlock valve is installed below a twin screw auger beneath the sugar silo. The valve then feeds into a 4” pressure pneumatic conveying line handling 9,000 lbs/hr of sugar. Sugar tends to be hydroscopic and builds up on the walls of the valve’s housing and headplates.


Meyer provided an 8×8 HDX (heavy duty) Rotary Airlock Valve. They are engineered with over-sized shafts to handle tough applications such as processing sugar. The blade construction was modified for this project.. Meyer added a knife edge bevel which reduced the land area and drag on the housing and headplates. Meyer’s blade construction is up to 2 times thicker than many other valve manufacturers. This provides the extra strength to power through chunk pieces. It also eliminates housing build-up issues. Meyer air purged the Teflon packing with a lantern ring and high pressure compressed air to improve packing life.

white hdx rotary airlock valve

“The Meyer 8″ HDX we installed is the best rotary valve I’ve ever seen.” – Jim Lierow


The frequent downtime was eliminated and company saved thousands of dollars in lost production and maintenance costs after the current valve was replaced with the Meyer 8X8HDX. According to Jim Lierow, “the Meyer 8” HDX valve we installed is the best rotary valve I’ve ever seen.”


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