Air blaster

An air blaster or air cannon is a de-clogging device composed of two main elements: a pressure vessel (storing air pressure) and a triggering mechanism (high speed release of compressed air). They are permanently installed on silos, bins and hoppers walls for all powdery form of materials, and are used for preventing caking and allowing maximum storage capacity.

Air blasters do not need any specific air supply. Available plant air is enough with a minimum of 4 bar air pressure (60 psi or 400 kPa), although 5 to 6 bar are preferred for better results (75 to 90 psi). The average air consumption is moderate, and depends on the number of firings per hour, size of the pressure vessel, and number of air cannons installed. For instance, a 50-liter air cannon consumes 0.60 Nm³/hour at 6 bar air pressure (90 psi or 600 kPa), with 2 firings per hour.

The compressed air contained in the pressure vessel is instantly released, and the achieved blast, called the impact force, evacuates material sticking to the walls (rat holing), as well as breaking potential bridging thanks to the shock wave obtained.

The blast are usually organized by using an automatic sequencer

An efficient air blaster should be designed to ensure:

Usually 2 versions exist A high temperature version: mainly for heat exchanger and cooler applications to remove clogging and to avoid costly plant stoppages and downtime. A low temperature version: to eliminate build-up and dead stock for powdery and granular materials thus preventing caking and allowing optimization of storage capacity.

Air blasters solves problem occurring in cement factories among other industries, with blockages occurring in preheater towers (Kiln inlet, Cyclones, riser ducts...etc.) and in grate coolers, thus providing substantial savings.

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Wikipedia