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In the design of industrial factory buildings, different production processes have varying requirements for the structures. Precision instrument and equipment production facilities necessitate constant temperature, humidity, and cleanliness; while certain hot workshops and dusty areas require good ventilation and dust removal systems. For industrial enterprises such as chemical, pharmaceutical, and petrochemical companies, due to the risk of explosions during production, the design of the factory buildings must carefully consider explosion prevention measures, in addition to meeting production process requirements. In the event of an explosion, efforts should be made to minimize the loss of life and property. Shenzhen Zhongnuo Testing Technology Co., Ltd. offers insights on the design of buildings for explosive areas and electrical wiring systems, for your reference only.
Basic technical measures for explosion-proof in factory design
(1) For factories (such as plants) with explosive hazards throughout the entire industrial area, the overall planning and design should consider factors like the production processes, types of products, production characteristics, and degree of danger of hazardous materials within the buildings. After determining the hazard level of the buildings, zoning planning should be carried out. The distance between buildings within the hazardous material production area and surrounding villages, highways, railways, towns, and the factory's living facilities should be calculated based on the hazard level of the buildings and the amount of stored materials, and the larger value should be selected according to regulations. If the required distances cannot be met due to factory site limitations, protective barriers must be established, such as protective embankments or reinforced concrete walls. Protective barriers must be set for Class A buildings. The layout should be adapted to the local conditions, making full use of the terrain and地貌 to achieve an optimal and reasonable arrangement.
(2) For buildings and workshops within an industrial plant that produce and utilize goods, they should be arranged as centrally as possible within the same area. The distance between these buildings and workshops should meet the safety requirements for fire prevention. This arrangement facilitates the unified treatment of fire-resistant and explosion-proof structural elements such as fire walls.
(3) Workshops with explosive hazards should be located in single-story buildings. If the building must be multi-story due to process requirements, they should be placed on the upper floor.
(4) When local explosion-proof rooms are installed in general factory buildings or workshops, these rooms should be as close to the exterior wall as possible. Equipped with specially designed windows that are easy to open outward, this facilitates the resolution of pressure relief area and is also convenient for extinguishing fires.
(5) In the factory, workshops with high and low levels of danger should be separated by sturdy fire-resistant walls (brick or reinforced concrete walls). It is advisable to open doors on the exterior walls for inter-workshop communication using corridors or balconies; or create a double-leaf door in the fire-resistant wall, aiming to stagger the doors as much as possible to mitigate the force of the explosion shockwave and reduce the impact area.
(6) For equipment prone to explosion, it should be placed as close to the exterior wall or near windows as possible, or outdoors, to minimize its destructive force.
(7) Production and storage of hazardous materials of different nature should be separated, such as those requiring separation from oxygen.
(8) Do not locate explosive hazard areas in basements or semi-basements due to poor ventilation, which can significantly impact accidents and is不利于 evacuation and rescue efforts.

Based on the basic requirements of GB 15577 "Safety Code for Dust Explosion Prevention," in防爆construction and modification in explosive dust environments, the following five major explosion prevention measures can primarily be adopted (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.).
Anti-knock
1. Definition: A suppression technology that allows the containment structure to withstand the high explosion pressure when an explosion occurs within it, where flammable dust and gaseous oxidizers or air are present, ensuring the containment is not damaged.
2. Objective: By enhancing container wall thickness and improving materials, external damage can be minimized even in the event of a dust explosion.
3. Basic Requirements:
When producing and handling powders that can cause explosions, if there is no explosion suppression device and no pressure relief measures, all process equipment should be designed to be explosion-proof and capable of withstanding the overpressure generated by internal explosions without bursting.
(2) The connecting sections between various process equipment (such as pipes, flanges, etc.) should have the same strength as the equipment itself. For connections between high-strength and low-strength equipment, explosion-proof devices should be installed.
(3) Equipment with explosion-proof pressure and explosion-proof pressure impact resistance should comply with the requirements of GB/T 24626.
Explosion Relief
1. Definition: A controlled explosion technique that, during an explosion within an enclosed package, allows the high temperature, high-pressure combustion products, and unburned materials to be released through pre-set weak points on the package to a safe direction before the explosion pressure reaches the package's limiting strength, thus preventing the package from being destroyed.
2. Purpose: To reduce explosion losses by installing explosion relief devices.
3. Methods: Two types of explosion relief - flameless and flammable.
4. Basic Requirements:
When the strength of the process equipment is insufficient to withstand the overpressure generated by internal dust explosion under actual working conditions, an explosion relief port should be installed. The relief port should face a safe direction, and its size should comply with the requirements of GB/T 15605.
(2) Indoor dust explosion hazard process equipment should be vented to a safe outdoor direction through pressure relief ducts. The pressure relief ducts should be as short and straight as possible, with a cross-sectional area not less than that of the relief opening, and their strength should not be less than the strength of the protected equipment container.
(3) Equipment inside the room that cannot vent explosions to the outside through a pressure relief conduit should be equipped with flameless venting caps.
(4) Process equipment with inline piping should be designed to withstand at least 0.1 MPa of internal overpressure.
Section 3: Explosion Suppression
1. Definition: During the initial stage of an explosion, extinguish flames and suppress (prevent) the development of dust explosion through physical and chemical means.
2. Purpose: To preemptively detect and extinguish fires, as well as suppress explosions by installing explosion suppression devices.
3. Basic Requirements:
Process equipment with a risk of dust explosion should be protected by explosion suppression devices.
(2) If a monitored explosion suppression device is used, it should comply with the requirements of GB/T 18154.
(3) Explosion suppression system design and application should comply with the requirements of GB/T 25445.
Four, Explosion-proof
1. Definition: Technology used to prevent the spread of an explosion after it has occurred, through physical and chemical actions.
2. Purpose: To prevent the spread of flame through pipes or other passageways
3. Basic Requirements:
(3) Equipment and facilities with dust explosion hazards that are interconnected through pipelines should be equipped with explosion-proof devices on the pipelines.
(2) Equipment and facilities with dust explosion hazards that are interconnected through pipelines should be equipped with explosion suppression devices. The shutdown direction should align with the direction of explosion propagation.
Five: Inertizing
For processes such as crushing, grinding, drying powders, and pneumatic conveying through pipes in sealed containers, inert gases like nitrogen, carbon dioxide, halogenated hydrocarbons, argon, helium, and steam are introduced, as well as inert dusts such as fire extinguishing powder, chemical dry powder, and mineral rock powder. This is to dilute combustible components and reduce the oxygen content in the environment.

Basic Dust Explosion Proof Construction Standards
In facilities where explosive dust is present, such as flour mills, feed factories, grinding workshops, and plastic production plants, the requirement for explosion-proofing on-site is particularly crucial. The installation and use of explosion-proof wiring, electrical equipment, dust removal systems, architectural layouts, and explosion-proof venting must all comply with the relevant dust explosion-proof standards. Based on a wealth of explosion-proof electrical construction and modification cases, Shenzhen ZhongNuo Testing Technology Co., Ltd. has summarized the following points:
1. Structure and layout of the building
Process equipment with a dust explosion hazard or buildings (structures) with combustible dust should be separated from other buildings (structures), and their fire protection distances should comply with the relevant provisions of GB50016.
(2) The building should be a single-story structure, with a lightweight roof design preferred.
(3) The structural requirements for multi-story buildings are as follows:
A. Multi-story buildings are best suited for frame structures.
B. Buildings without frame structures must have explosion relief openings installed on the walls in compliance with requirements.
C. If windows or other openings are used as blast relief ports, they must be calculated and ensured to effectively release pressure during an explosion.
(4) The requirements for evacuation routes are as follows:
A. The work area should have evacuation routes, and the number and location of the evacuation routes should comply with the provisions of GB50016.
B. The door should open outward and no threshold should be installed.
C. Detailed road signs and emergency lighting should be set up for evacuation routes.
2. Process Equipment
If the equipment in the factory is at risk of dust explosion, it should be located on a higher floor of the building and near the exterior wall.
(2) Equipment with explosive hazards should be located in an outdoor area outside of the building.
(3) Equipment or devices that come into direct contact with dust (such as light sources, heating sources, etc.) should have surface temperatures lower than the respective dust's low ignition temperature.
(4) In areas where combustible dust is present, the transmission mechanisms of the equipment and installations shall comply with the following regulations:
A. The bearings of the processing equipment should be dust-proof and sealed. If there is a possibility of overheating, a detector capable of continuously monitoring the bearing temperature should be installed.
B. Belt drive is not recommended. If belt drive is used, a speed difference sensor and an automatic anti-skid protection device should be installed. In case of sliding friction, the protection device should ensure automatic shutdown.
(5) At the feed point of the process flow, a magnet, an air separator, or a sieve capable of removing impurities mixed with the material should be installed to prevent the collision of impurities with the equipment.
(6) Effective measures should be taken to prevent sparks from occurring when aluminum, zirconium, and other metal powders or powders containing these metals are in contact with stainless steel.
(7) Implement protective shutdown during explosions by installing multiple interlocked power supply control boxes, according to the size of the workshop. In emergencies, the power supply to all motors should be cut off promptly.
(8) All joints, inspection doors, baffles, and explosion relief coverings of the process equipment should be tightly sealed.
(9) The equipment housing should be made of non-flammable material
(10) The moving parts of the equipment should operate smoothly without any scraping, bumping, jamming, or rubbing.
(11) If the strength of the process equipment is insufficient to withstand the overpressure generated by internal dust explosion under actual operating conditions, an explosion relief port should be set, and the size of the relief port should comply with the relevant provisions of GB/T15605.
(12) The venting port should be located near potential ignition sources and should be as high as possible, ideally at the top or upper part of the containment structure. It must not vent towards flammable and explosive hazardous areas to prevent igniting others, and it must not vent towards public spaces to avoid causing injury from venting explosions.
3. Lightning and static electricity protection
Hazardous dust explosion areas should implement lightning protection measures in accordance with the relevant provisions of GB50057. When static electricity hazards are present, the following regulations should be adhered to:
All metal equipment, casing of devices, metal pipes, brackets, components, parts, etc., are generally grounded statically through antistatic materials or products. For those that are not convenient or prohibited by the process to be grounded directly, grounding can be achieved indirectly through conductive materials or products.
(2) Equipment directly used for containing static-dust powder, including conveyance pipes (belts) for the powder, should be made of metal or antistatic materials.
All metal pipe connections should be bonded.
(4) Operators should take anti-static precautions.
(5) Do not use metal conductors or meshes grounded directly to contact with high-speed flowing powders to dissipate static electricity.

With the development of the global energy and chemical industry, construction in explosive hazardous environments is becoming more widespread, making the prevention and acceptance of explosive environments increasingly important.
Especially in flammable dust environments, such as plastic factories, feed/food/grain processing plants, metal polishing and finishing workshops, papermaking/forestry wood powder/fiber dust factories, and so on, the number of projects for explosion-proof installation, design, and renovation is also increasing.
Whether it's large-area explosion-proof or local explosion-proof, if there are hidden dangers in product quality or installation/renovation quality,
Our personal and property safety is at great risk, so we must maintain quality control at every stage of production, ensuring the reliability and safety of explosion-proof installations and renovations.
Shenzhen Zhongnuo Inspection Technology Co., Ltd. offers explosion-proof construction and modification consulting services. With rich qualifications and case studies, it's a worthwhile choice!
Explosion-proof electrical modifications and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Testing Technology Co., Ltd.