Pneumatic Conveying Systems are balanced when airflow, material load and pipe geometry are in the correct proportions to each other.
Surging or Inconsistent Flow
Material arriving at the destination in pulses rather than as a flowing stream of material can be an indication of incorrect air-to-material ratio. This can be due to a number of reasons including incorrect feed rate or incorrect blow-through air pressure.
Pressure Drops or Spikes
If you are reading unexpected values on monitoring points then there could be a partial blockage, a worn seal or a number of leaking joints. Inspect the complete system, particularly around all unions and bends.
More Fines Than Usual
There is increased product degradation. The material is most likely to be getting damaged as it is hitting the walls of the pipe. The material is being conveyed at too high a velocity for the size of the particles in the product. For Pneumatic Conveying Systems, see www.aptech.uk.com/pneumatic-conveying-systems.
Blockages at Bends
Pugging tends to occur at elbows, bends and areas where there are reductions in cross-sectional area. This is due to a decrease in velocity and an increase in material contact with the pipe work surfaces. Excess fines and dust production can also create serious safety hazards and these should be kept under control. Guidance on the control of dust in industrial processes has been published by the HSE.
Higher Energy Bills
A blower that is drawing more current than normal but has no increase in material throughput is working against a restriction somewhere in the system. Use a pressure log to monitor the change in pressure over a few shifts to establish where in the system the problem has occurred.
Noise or Vibration in the Pipework
Rattling or even droning sounds in your pneumatic conveyor system pipes, which before weren’t there, usually indicate turbulent airflow. Most of the time this issue is created by a loose support bracket.
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