Rotary Airlock Feeder Sizing & Air Leakage Calculator
Calculate rotary airlock volumetric displacement, operating RPM, pocket fill factor, rotor blade clearance air leakage, and carryover blow-back CFM.
Throughput & Bulk Density
Differential Pressure & Clearances
Rotor Operating Speed & Blowby Leakage
| Required Rotor Speed (n): | -- RPM |
| Required Net Volumetric Rate: | -- m³/h |
| Rotor Clearance Blowby Leakage: | -- SCFM |
| Displacement Pocket Carryover Leakage: | -- SCFM |
| Feed Throat Venting Requirement: | -- |
| Estimated Drive Motor Rating: | -- HP |
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
What is the function of a rotary airlock feeder in pneumatic conveying?
A rotary airlock valve serves two simultaneous functions: (1) It mechanically meters bulk solid powder or pellets from a storage bin or dust collector hopper into a conveying line at a controlled volumetric rate, and (2) It maintains an airtight pressure seal between the atmospheric hopper and the pressurized (or vacuum) pneumatic conveying pipeline.
What causes air leakage through a rotary airlock valve?
Air leaks in two distinct ways: (1) Clearance Leakage (blow-by air escaping continuously across the precision 0.10 to 0.20 mm radial gaps between the rotating blades and stationary housing), and (2) Carryover Displacement Leakage (as each empty rotor pocket discharges solids into the pressurized pipe, it fills with high-pressure air and transports that compressed gas back up into the feed throat).
Why is an airlock vent hopper or venting shoe essential on pressure pneumatic lines?
If blowback leakage air (often 30 to 80 SCFM) escapes upward directly through the falling stream of incoming powder, it fluidizes or aerates the product, causing material to bridge, float, and refuse to drop into the rotor pockets. A vented feed shoe channels escaping air into an external dust collector, allowing solid powder to gravity-fall smoothly into the pockets.