Replacing rotary airlocks with Vacu-Valve trickle valve

Established in 1912, the quarry produces approximately 3 million tons of limestone products per year. Limestone is one of the basic ingredients in almost any construction project including houses, highways, sidewalks, drainage, and agricultural products.  Wagner Quarry provides the limestone for the eastern part of Ohio as well as other surrounding areas. The blasting, drilling, crushing, loading, and hauling operations required to extract this valuable resource generate an enormous amount of airborne dust which is captured on-site by large bag house dust collectors.

The Challenge
In April 2010, Maintenance Foreman Paul Schaffer decided to look for a better alternative to the problematic rotary airlock valves used to empty the mine’s dust collectors. The highly abrasive limestone dust made short work of the expensive rotary valves and their cumbersome drive assemblies were difficult to access for repair. Shaffer contacted Aerodyne product manager Bart Eggert who visited the quarry to offer his recommendations.  Bart learned that another major obstacle was the quarry’s winter shutdown period which left the rotary airlock valves unused for several months at a time.  The existing rotary valves would inevitably rust and jam up during this period, making costly repair or replacement of the valves necessary when production resumed.

The Solution
Mr. Schaffer made the decision to replace Wagner Quarry’s problematic rotary airlock valves with Aerodyne’s low-cost, low-maintenance Vacu-Valve® Platypus trickle valve.  Because the valve has no moving parts, requires no controls, lubrication, or power supply, it would not be affected by the seasonal shutdowns.  The Vacu-Valve easily handles the abrasive limestone dust and it is a fraction of the cost of the rotary airlock valves previously used. 

The negative pressure in the dust collector holds the duck-bill sleeve of the trickle valve closed, creating a tight airlock seal. 

As a head of material builds up above the valve, the weight forces the sleeve open allowing the dust to discharge continuously until the systems negative pressure automatically re-closes the valve.

Schaffer estimates savings between “$8,000 and $10,000 a year or more” with the installation of the Vacu-Valves.

Not only are there major savings on the initial cost of the valves but he says “it frees up maintenance personnel to work on other equipment”.

Another benefit to installing the Vacu-Valve trickle valve is an improved airlock seal. 

Rotary airlock valves progressively leak more and more air as they wear out.  This excess air intrusion harms the efficiency of the entire dust collection system.  The Vacu-Valves’ duck-bill sleeve can be replaced without the use of tools ensuring a consistent, easy to maintain, airlock seal.

More information Aerodyne Vacu-Valve® Platypus and Vacu-Valve® Armadillo

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