The air system must maintain enough velocity to suspend and transport the material without excessive settling, blockage or product damage.
The fan must overcome pressure loss from the intake, pipeline, bends, vertical lift, material pickup, separator, receiver and final filtration equipment.
The fan should preferably handle clean air. When material or dust passes through the impeller, wear, buildup, imbalance and maintenance requirements can rise significantly.
The fan supplies clean air before the material feeding point and pushes the air-material mixture toward the receiver.
The system pulls material toward a separator or receiver. The fan should be located after effective separation and filtration whenever possible.
Pressure loss rises with pipeline length, vertical lift, bends, valves, pickup devices and material loading. The separator, receiver and final filter also add resistance.
Fan selection should be based on the full conveying route at the required feed rate. Selecting only by pipe diameter can result in low capacity, blockage or excessive energy use.
For a new system, material characteristics, capacity, pickup method, pipe route and receiving equipment should be evaluated before selecting the fan.
For an existing system, compare the current fan duty with actual feed rate, pipe changes, blockage points, leakage, separator condition and product properties.
This page focuses on low-pressure or medium-pressure dilute-phase conveying where material is suspended in a moving air stream. Dense-phase and high-pressure conveying normally require different equipment such as positive-displacement blowers or compressors.
For abrasive, hard or valuable material, the fan should normally remain on the clean-air side. Direct material passage through the impeller can accelerate wear, create imbalance and damage the fan.
Pressure depends on pipe length, pipe diameter, bends, vertical lift, pickup device, feeding rate, material loading, separator resistance and the required conveying velocity.
Bulk density, particle size, hardness, moisture, stickiness and fragility affect conveying velocity, pipe wear, blockage risk and product damage.
Only when the required airflow and pressure fall within a suitable fan operating range. Dense-phase, high-pressure or long-distance heavy-duty conveying usually requires a different air source.
9-19, 9-26, 8-09 and 9-12 are higher-pressure clean-air directions. 4-2×72 may suit large-volume lower-pressure air-supply duties after full operating-point review.