Comprehensive Prevention and Control Measures of Dust Explosion in Grain Steel Silos

With more and more perfect application technology, grain steel silo has become main storage type of grain and oil. But in recent years, the dust explosion accidents of grain steel silo are on the rise in grain and oil processing plants. It is reported that the phenomenon is very serious even in some developed countries. The dust explosion not only pollutes the environment, but also may cause serious casualties and significant economic losses. Therefore, for us, it is necessary to take safe and effective prevention measures to keep from it. We should pay enough attention to it. Starting from the design, we should consider various factors and adopt comprehensive prevention and control measures in order to achieve effective control of dust.

Strengthening management, improving safety consciousness and enhancing responsibility sense

• We should strengthen the knowledge training of dust explosion and silo safety for workers and actively do periodical safety drills, establish strict working rules and strictly operate in accordance with operation procedures. In addition, actively improve the sanitary environment and sanitary cleanup to maintain good ventilation conditions inside the silo.
• We should do well in comprehensive inspection work for the safety. We must carefully analyze various risky factors of dust explosion. The related safety checks shall be comprehensive and targeted to find the problems in a timely manner, leaving no hidden dangers
• We should equip the related safety facilities. The operators shall be familiar with performance and operating conditions and skills of the equipments and instruments, and do well in the maintenance. The electric welding and cutting works shall be prohibited under no normal conditions unless we can take more security precautions. After the operation, we should do a thorough examination and eliminate all the risks to ensure the safety of grain silos.

Eliminating the impacting factors of dust explosion from the design on 

• Making overall plan and design of silo area as far as possible as the principle of integrated design. For the explosive and dangerous buildings and machinery equipments, we should set up special safety wall and safety belt and install appropriate fireproof materials; for lightning, grounding, anti-static electricity and fire protection design, we should do a comprehensive consideration and take safety precautions.
• In the structure design, we should set the safety devices, for example, ventilation window, ventilation hole, check holes, etc. in order to maintain normal inner-silo pressure; for the damaged parts (for example, corridor, etc.), we should set the anti-explosion window to achieve the purpose of eliminating explosion. 
• The design of ventilation and dust removal. The reasonable design has played a positive role in preventing dust explosion. For the design, it is essential to choose appropriate parameters and methods. The wind velocity of air pipe is better at 15-17m/s. We can directly collect the dust at the dust source and expel to the outside through the dust collector. We can use the combination way of expelling and impelling air to achieve the purpose of complete ventilation and natural ventilation by the difference of pressure or temperature of the silo. 
• In addition, we can adopt the dust cover and protective cover. We should choose a suitable position and cover structure especially for the unloading parts of grain silo to form an air belt to prevent the dust. Near the dust source, we can install dust suction cover, which would make the dust be restricted to a small range of area. This will go to ensure that enough negative pressure in the air suction cover and cause no dust diffusion. The air stream is smooth in the cover and the contraction angle is not more than 60°. In the aspect of air flowing speed, we should select 3-5m/s (grain) and 0.5-1.5m/s (powder). After adding the flanges around dust cover, we should try to reduce invalid flowing, which can save 25% of air suction. Its designed air speed is 0.5-2.5m/s. When the mechanical equipments cannot be sealed due to technological limitation, we can choose open cover and external suction cover. 
• The grain conveying design, we should choose short process, reasonable arrangement of equipments with the use of explosion proof equipments and good sealing and magnetic separation equipment. The position of higher dust concentration is used of the double purification. At the feeding end and throwing end of the belt conveyor, we must set reasonable dust cover. Because the conveyor on the silo roof adopts the unloading car and the dust source is flowing, the dustproof device should be designed reasonably. The screw conveyor is tight in structure, so generally it is unnecessary to set dustproof device. But when there is greater drop gap of the grain, we should be arranged the expansion box on the lower part of the air suction cover. For bucket elevator, conveyor and other equipments, we shall be equipped with a speed detection device, spraying fire extinguishing device and other devices. 

Using new technology of dust explosion

• Spraying dustproof technology can not only improve current method of dust control, but also provides us with a new idea. The technology can play the better inhibition effect for less than 30μm of fine dust particle and absorb reproducing dust on the grain surface. So it is conducive to fundamentally control dust explosion.
• According to the information, the Esso Company from the USA takes white oil as the dustproof agent. The spraying dosage is only 0.02% of flowing volume of the material, which can effectively control the dust in the grain. In the world, many developed countries have been widely used in this new technology in the management of grain storage and transportation, achieving good results. But the technology is still required of further research and improvement.
• In addition, in order to effectively prevent dust explosion in the grain silo, the technical management and training should be strengthened as well as dust removal and explosion prevention measures.

FLYER Company has rich experience in the aspect of dust explosion prevention. We believe that we can help you to succeed in application of grain steel silo. Welcome to contact with us freely.