Air blasters
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[edit] Air Blasters
Air Blaster is a de-clogging equipment composed of two main elements : a pressure vessel (storing air pressure) and a Triggering mecanism (high speed release of compressed air).
Air blasters are permanently installed on silos, bins and hoppers walls for all powdery form of materials, thus preventing caking and allowing maximization of storage capacity.
Air Blaster do not require any specific air supply, available plant air is sufficient with a minimum 4 bars air pressure (60 PSI), 5 to 6 bars for better results (75 to 90 PSI).
The average air consumption is moderate and depends on firing number per hours, size of pressure vessels, and number of air Blasters installed. For instance, a 50 liters air Blaster consumes 0.60 Nm3/hour at 6 bars air pressure (90 PSI) with 2 firing per hour.
The compressed air contained in 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 a automatic sequencer
[edit] Operating principle
[edit] Phase 1 Air feeding mode
Air supply from plant air compressor passes through a 3/2 way Solenoid Valve feed the QRV (Quick Release valve) and reach the Triggering mechanism with its piston disc in closed position. The air reservoir is then pressurized in less than 15 seconds. (depending on air pressure and air volume used)
[edit] Phase 2 Waiting mode
An air pressure equilibrium between air circuit / Triggering mechanism / Pressure vessel is created…..This is the waiting mode.
[edit] Phase 3 Blasting mode
When activated, solenoid valve purges the air circuit, thus creating an air vacuum. Then, piston inside Triggering mechanism is abruptly pushed back by negative pressure…creating a sudden blasting from the air contained in pressure vessel. This phase is measured in milliseconds only. Then the cycle starts again at Phase 1.
[edit] Best designs
An efficient Air Blasters should be designed with several objectives in mind:
• Complete safety for the operators thus avoiding harsh rodding or other manual cleaning method;
• A sturdy design able to cope with the most severe operating conditions;
• Easy maintenance thanks to an accessible Triggering device;
• A metal to metal construction design making the Air Blaster extremely reliable even in harsh environment (such as exposed to heat and/or dust);
• A cost effective solution to all customers willing to prevent hoppers, bins and silos discharge interruption as well as process disruption.
[edit] Construction
Usually 2 different versions exist:
• High Temperature version mainly for heat exchanger and cooler applications to remove clogging and to avoid costly plant stoppages and downtime;
• Low Temperature to eliminate build up and dead stock for powdery and granular materials thus preventing caking and allowing optimization of storage capacity.
[edit] Installation
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.
[edit] See also
- air cannon Removing build up using pneumatic air cannons.
[edit] External links
- Air cannon The technology and specifications used in the article are provided by Staminair Corporation.
