LQ-SR
Standard Rotary Airlock Valve
General-purpose airlock for gravity discharge of free-flowing powders and granules.
Dust Collection Systems
Rotary Airlock Valves for Industrial Dust Collection
On a dust collector the rotary valve is the boundary between the clean side and the plant. Its job is to release collected dust continuously while letting as little air as possible back up into the hopper. Get it wrong and the filter runs at a higher air-to-cloth ratio, the bags wear faster and the differential pressure never settles.
Request a QuoteThe valve as a pressure boundary
In a negative pressure baghouse the fan pulls air through the bags and the hopper sits under vacuum. Every cubic metre of air that leaks up through the valve is air that bypasses the filter, so the effective filtration area drops and the cleaning cycle has to work harder. In a positive pressure collector the same valve has to resist dust being pushed out through the rotor pockets. Both cases are solved with the same three variables: pocket geometry, tip clearance and rotor speed.
Sizing for the dust, not the tonnage
Dust collector valves are usually sized by the hopper outlet rather than the collection rate, and that is a mistake. Fine dust has a low bulk density and a strong tendency to aerate, so a large pocket at high speed leaks far more air than a small pocket at low speed handling the same mass. We size the pocket from the collected mass per hour and the bulk density, then check the leakage against the fan margin.
Typical failure modes
Three things go wrong: the valve is too small for the dust rate and the hopper floods; the clearance opens through wear and leakage rises until the baghouse cannot hold vacuum; or the material bridges in the inlet throat because the transition is too abrupt for a cohesive dust. Each has a different fix, and all three are cheaper to design out at the quotation stage than to correct on site.
Selection inputs we ask for
Collected mass per hour, bulk density, hopper outlet size, the pressure at the hopper (positive or negative), dust temperature, and whether the dust is cohesive or free-flowing. With those five numbers we can specify a valve and state the expected leakage.
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