What is Rotary Airlock Valve Capacity?
Rotary airlock valve capacity is the required rotor pocket volume needed to convey a specified amount of bulk material per revolution. Rotary valves are used in pneumatic conveying systems to feed material from hoppers into pressurized or vacuum conveying lines while maintaining an air seal. Sizing the valve correctly ensures the system meets throughput requirements without overloading or starving the line.
How to Calculate Rotary Airlock Valve Capacity
Here is the formula:
[\text{Capacity} = \frac{R}{D} \times \frac{100}{E} \times \frac{1}{S}]
Where:
- Capacity is the required rotor pocket volume per revolution (ft³ or m³).
- R is the rate of conveying (units per minute).
- D is the product density (units per ft³ or m³).
- E is the valve efficiency (as a percentage).
- S is the rotor speed (RPM).
Calculation Example
A system conveys 150 units per minute. The product density is 6 units/ft³, valve efficiency is 80%, and rotor speed is 250 RPM.
[\text{Capacity} = \frac{150}{6} \times \frac{100}{80} \times \frac{1}{250}]
Step by step:
- 150 / 6 = 25
- 100 / 80 = 1.25
- 1 / 250 = 0.004
[\text{Capacity} = 25 \times 1.25 \times 0.004 = 0.125]
The required rotor pocket volume is 0.125 ft³ per revolution.