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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 ==Operating principle== *Phase 1: Air feeding: Air supply from the air compressor passes through a 3/2 way solenoid valve feed, the Quick Release Valve (QRV), 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 the air pressure and air volume used. *Phase 2: Waiting: An air pressure equilibrium between air circuit, triggering mechanism, and pressure vessel is created. *Phase 3: Blasting: When activated, a solenoid valve purges the air circuit, thus creating an air vacuum. Then, the piston inside triggering mechanism is abruptly pushed back by negative pressure, thus creating a sudden blast from the air contained in the pressure vessel. This phase is measured in milliseconds. *Then the cycle repeats again at Phase 1. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Air blaster」の詳細全文を読む スポンサード リンク
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