How to effectively prevent dust explosions in workshops

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When it comes to explosions, people always think of the thunderous noise produced by **or combustible gas explosions. What is not known is that dust particles floating in the air can also cause explosions of even greater intensity. For detecting dust levels in the feed and food industries, how should we make a choice? Ai Technology will explain in detail using CP Group’s Luoyang feed factory as an example. I. Hazards of dust explosions: Compared to gas explosions, dust explosions are characterized by multiple explosions. During the first explosion, the shock wave blows up the dust that is deposited on equipment or the ground, triggering an explosion. Since the dust concentration is much higher during the second explosion, its intensity is greater than that of the first explosion. In August 2014, a dust explosion occurred in the automobile wheel hub polishing workshop of Kunshan Zhongrong Metal Products Co., Ltd., resulting in 97 deaths, 163 injuries, and complete destruction of the workshop. Subsequently, the **\"Five Provisions on Strict Prevention of Dust Explosions in Enterprises\"** were issued, stipulating that \"dust should be tested and cleaned regularly at each shift as required.\" Therefore, dust monitoring in the workshop is urgent. II. Selection of dust detection systems for the food and feed industries. Common explosive dusts in the feed and food industries include feed powders (fish meal, blood meal), starch, flour, etc. Dust accumulation areas are mainly concentrated in the production workshops, while the process sections include feeding ports, storage tanks, elevators, silo tops, conveyor belts, and warehouses. Since the lower explosion limits for different dusts vary, the range selection for the corresponding dust detectors also needs to be determined based on specific circumstances. And the alarm value should be set based on the lower explosion limit. Since most production workshops are explosion-proof areas, the selection of products must take into account relevant explosion-proof certifications (for indoor environments, dual certification for gas and dust explosion protection is recommended). In terms of functions, it should have features such as over-concentration alarm, data display, and automatic interlocked exhaust. Since workshops are often multi-story structures with monitoring points that are far apart from each other, it is necessary to be able to display the data from all these monitoring points together in the control room. III. Case Study of Dust Control Solutions at CP Feed Factory 1. Company Introduction: CP Group is a well-known multinational company founded by Thai-Chinese entrepreneurs. It operates 213 companies in China, with annual sales exceeding 50 billion RMB; its feed products are renowned brand names across the country. 2. Enterprise requirement analysis: The explosive dust material involved at CP Feed Factory is mainly corn flour, with an explosion threshold of 45 g/cm^3. Therefore, the range of the dust detector should not be set too low; the common range of 0–1000 mg/cm^3 is not suitable for such conditions, while a range of 0–4000 mg/cm^3 is more appropriate. Following on-site inspections, the locations with potential explosion hazards are mainly five process points: conveyor belts, elevators, crushers, feed inlets, and silo roofs. These five process points require close monitoring. Enterprises require automatic interconnection; therefore, each detection point must be equipped with an audio-visual alarm and connected to the exhaust fan. Since each monitoring point is located in a separate area and it’s not guaranteed that there will always be someone there, a main control computer needs to be installed in the monitoring room on the second floor to display the data from all monitoring points in one place. The production workshop is a explosion-proof area, and all product components are of explosion-proof type. 3. Design of dust detection solution: Online dust monitors are installed at five process points in the workshop, namely the conveyor belts, elevators, crushers, feeding ports, and warehouse roofs, for monitoring purposes. Explosion-proof audible and visual alarms are deployed on-site to provide alerts when levels exceed the specified limits. Furthermore, the dust meter is connected to the workshop exhaust fans to enable automatic exhaust ventilation at high concentrations. In addition to monitoring at each process point, an industrial computer is installed in the control room on the second floor; the screen displays the dust concentration values from all monitoring points in real time, and it also allows for data recording and export for safety inspections.