Fireproof partition dividing method for dust explosion dangerous area

Abstract

The invention provides a fire compartment division method for a dust explosion dangerous area, which is used for preventing and limiting fire spreading and influence range expansion after a dust explosion accident occurs, and eliminating major production safety accident hidden dangers in the dust explosion field. Carrying out explosive screening test and explosion risk analysis on the process dust in the explosion-related area; the types of the buildings in the explosion-related area are distinguished; determining the fire risk of the building in the dust explosion-related area, and determining the maximum permissible floor number requirement of the building in the fireproof subarea and the maximum permissible building area of the fireproof subarea; judging whether a major production safety accident potential exists in the explosion-related area or not; formulating a fire compartment division principle; and determining a fire partition division scheme and a fire separation scheme. The method is a post prevention measure, has the characteristics of high applicability, high practicability and the like, and has important guiding significance on dust explosion control work.

Description

Technical Field

[0001] The present invention relates to the technical field of dust explosion control, and more specifically to a method for dividing fire zones in a dust explosion hazardous area. Background Art

[0002] In order to eliminate the major accident hazards in the field of dust explosion hazard, the workplace must be divided into fire zones. Fire zone division is to divide the workplace into several areas that can effectively control fire. It is a "post-event prevention" measure. Fire zones are usually separated by firewalls, fire doors, fire curtains and fire water curtains. At present, experts and colleagues emphasize the "pre-event prevention" of dust explosions, while "post-event prevention" is rarely studied. Both are equally important. The significance and importance of "post-event prevention" is mainly reflected in the following four aspects:

[0003] 1. Protect personnel safety. Fire zoning can effectively limit the spread of dust explosions, thereby reducing the possibility of personnel being exposed to explosion risks;

[0004] Second, prevent chain reactions. By carefully and scientifically dividing the hazardous areas, dust explosions can be effectively prevented from spreading to the entire workplace and forming a chain reaction;

[0005] 3. Equipment and property protection: Dividing factories or equipment nodes into different fire zones can reduce the scope of property damage and avoid equipment damage and production stagnation caused by dust explosions to the greatest extent;

[0006] 4. Safety regulations require that in many countries and regions, there are strict regulations requiring industrial and trade enterprises to assess potential dust hazards and take corresponding preventive measures. The fire zoning of dust explosion hazard areas is an important part of this.

[0007] There is no fire zoning method involving the field of dust explosion prevention in current industrial and trade enterprises. In previous fire zoning methods, the scope and boundaries of each zone were vague, which led to doubts about the accuracy of the zoning. At the same time, the existing fire zoning method is only applicable to a certain type or size of workplace, and is not flexible enough or too strict in other cases. In addition, the existing fire zoning method requires a lot of manual intervention and professional knowledge to formulate, which has a certain threshold for ordinary practitioners. Summary of the invention

[0008] The purpose of the present invention is to provide a method for fire zoning dust explosion hazardous areas in response to the above-mentioned problems existing in the prior art. The method can well overcome the above-mentioned limitations and can also prevent and limit the spread of fire and the expansion of the impact range after a dust explosion accident occurs.

[0009] In order to achieve the above object, the method is characterized in that it includes the following steps:

[0010] A method for dividing fire zones in dust explosion hazardous areas comprises the following steps:

[0011] Step S1: Conducting explosive screening test on process dust in the explosion-related area;

[0012] Step S2: Conduct explosion risk analysis on process dust in the explosion-related area;

[0013] Step S3: distinguishing the types of buildings in the explosion-related area, where buildings include buildings and structures;

[0014] Step S4: Determine the fire hazard of buildings in dust explosion-prone areas. The fire hazard includes fire hazard level and fire resistance level. According to the fire hazard level and fire resistance level, determine the maximum number of floors allowed for buildings in fire zones and the maximum allowable building area of ​​fire zones.

[0015] Step S5: Determine whether there are any major production safety accident hazards in the explosion-related area;

[0016] Step S6: Formulate fire protection zoning principles;

[0017] Step S7: For areas with major production safety accident hazards, determine a fire zoning plan based on the fire zoning principle;

[0018] Step S8: Determine the fire separation scheme between fire partitions.

[0019] As mentioned above, the explosive screening test of process dust in the explosion-prone area includes:

[0020] Step S101: In a single test, the maximum value of the explosion pressure of the process dust in the explosion test device is recorded as P ex,a ;

[0021] Step S102: The pressure of the process dust when it is detonated by the chemical ignition device in the explosion test device is recorded as P ignition ;

[0022] Step S103: After the process dust is detonated by a chemical igniter under atmospheric pressure, the pressure rise value of the explosion in the explosion test device is recorded as ΔP ignitor ;

[0023] Step S104: The explosion pressure ratio is recorded as PR, PR = (P ex,a -ΔP ignitor ) / P ignition; If the calculated explosion pressure ratio PR is greater than or equal to 2, the process dust is explosive dust; otherwise, the process dust is non-explosive dust.

[0024] As mentioned above, the explosion risk analysis of process dust in explosion-prone areas includes: analyzing whether the five elements necessary for dust explosion are simultaneously present in the explosion-prone areas, including: the presence of combustion-supporting gas, the process dust being explosive dust, the presence of an ignition source, a dust cloud within the explosive concentration range, and the process dust being located in a relatively closed space.

[0025] As described above, distinguishing the types of buildings in the explosion-prone area includes the following steps:

[0026] Step S301: If the building in the explosion-related area has an operating post, the building is determined to be a building; otherwise, proceed to the next step S302;

[0027] Step S302: If the building in the explosion-prone area has a single function, the building in the explosion-prone area is determined to be a structure; otherwise, proceed to the next step S303;

[0028] Step S303: If the building area of ​​the building in the explosion-prone area is less than or equal to half of the maximum allowable building area of ​​the fire protection zone in the building fire protection design specification, and the number of normal production mobile operation posts is less than 3 people, the building in the explosion-prone area is determined to be a structure;

[0029] Otherwise, the buildings in the explosion-prone areas are judged as structures.

[0030] As mentioned above, the determination of whether there are major production safety accident hazards in the explosion-related area includes the following steps:

[0031] If a process dust that is combustible dust is mixed with another process dust to produce a reaction that exacerbates the risk of explosion, and they share a dust removal system, there is a major potential for production safety accidents in the explosion-related area;

[0032] If process dust of combustible dust is mixed with combustible gas and shares a dust removal system, there is a major potential risk of production safety accidents in the explosion-related area;

[0033] If two or more independent buildings share a dust removal system for dust-generating points, there will be a major production safety accident hazard in the explosion-related area;

[0034] If dust-generating points in different fire zones of the same building share a dust removal system, there will be a major hidden danger of production safety accidents in the explosion-related areas;

[0035] If the dust removal systems of different buildings and structures are interconnected through dust removal ducts, fans, and air outlet ducts, or if the dust removal systems of different fire protection zones are interconnected through dust removal ducts, fans, and air outlet ducts, there will be a major potential safety hazard in production safety accidents in the explosion-related areas.

[0036] As mentioned above, the maximum allowable building area of ​​the fire compartment is based on the fire hazard level and the fire resistance level, and the maximum allowable number of floors is limited. The maximum allowable building area of ​​single-story factories, multi-story factories, high-rise factories, and underground or semi-underground factories is further determined under the conditions of fire hazard level, fire resistance level, and maximum allowable number of floors.

[0037] As mentioned above, the principles of fire zoning include:

[0038] Different buildings cannot be divided into one fire zone;

[0039] Buildings and structures cannot be divided into one fire zone;

[0040] Interconnected structures can be divided into one fire zone;

[0041] Fire separations should be used between fire compartments;

[0042] The maximum allowable building area of ​​the fire compartment meets the maximum allowable building area of ​​the fire compartment determined in step S4.

[0043] As mentioned above, the fire separations between fire compartments include fire walls, fire doors, fire glass, fire partitions, fire shutters and fire water curtains.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] First, the division method is based on reliable scientific research and practical experience, comprehensively considering all types of process dust and actual working conditions in the explosion-related area, and deriving definite fire zones and fire zone boundaries to ensure the control of dust explosion hazards;

[0046] Second, the classification method is flexible and applicable to industrial and trade enterprises of different types, natures and sizes, as well as various dust generation and accumulation situations existing in different working areas;

[0047] Third, the division method is clear and simple, easy to understand and operate, so that practitioners can easily and correctly make fire zoning divisions, and take corresponding safety and protection measures based on the fire zoning divisions, while considering cost-effectiveness factors to achieve maximum safety protection at a relatively low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flow chart of fire protection zone division of the present invention;

[0049] Figure 2 is a plan view of an explosion-related area of ​​an example of the present invention;

[0050] 1- No. 6 coal bunker of circular material yard; 2- T4 transfer station; 3- No. 5 coal bunker of circular material yard; 4- belt corridor; 5- No. 4 coal bunker of circular material yard; 6- T3 transfer station; 7- No. 3 coal bunker of circular material yard; 8- belt corridor; 9- No. 2 coal bunker of circular material yard; 10- T2 transfer station; 11- central control room; 12- No. 1 coal bunker of circular material yard; 13- T1 transfer station.

[0051] Figure 3 It is a fire zoning division diagram of an explosion-related area in an example of the present invention. DETAILED DESCRIPTION

[0052] In order to facilitate those skilled in the art to understand and implement the present invention, the present invention is further described in detail below in conjunction with embodiments. The embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0053] like Figure 1 As shown, a method for dividing fire zones in dust explosion hazardous areas includes the following steps:

[0054] Step S1: Conducting explosive screening test on process dust in the explosion-related area;

[0055] The test is carried out using a 20L spherical explosion test device. If the explosion pressure ratio (PR) is greater than or equal to 2, the process dust in the explosion-prone area is identified as explosive dust; otherwise, the process dust in the explosion-prone area is considered to be non-explosive dust.

[0056] In one example, the settings are as follows:

[0057] Step S101: In a single test, the maximum value (absolute pressure) that the explosion pressure of the process dust in the explosion test device can reach is recorded as P ex,a ;

[0058] Step S102: The pressure (absolute pressure) of the process dust when it is detonated by the chemical ignition device in the explosion test device is approximately atmospheric pressure in this example, denoted as P ignition ;

[0059] Step S103: The pressure rise value of the process dust after being detonated by the chemical ignition device under atmospheric pressure in the explosion test device is recorded as ΔP ignitor ;

[0060] Step S104: The explosion pressure ratio is recorded as PR, PR = (P ex,a -ΔP ignitor ) / P ignition ; If the calculated explosion pressure ratio (PR) is greater than or equal to 2, it means that the process dust is explosive dust; otherwise, the process dust is considered to be non-explosive dust.

[0061] Step S2: Conduct explosion risk analysis on process dust in the explosion-prone area:

[0062] Analyze whether the explosion-prone area has the five necessary elements for dust explosion, including: the presence of combustion-supporting gas, the process dust is explosive dust, the presence of ignition source, the dust cloud within the explosive concentration range, and the process dust is located in a relatively closed space. The specific steps are as follows:

[0063] Step S201: explosive dust analysis, using the method of step S1 to determine whether the process dust is explosive dust;

[0064] Step S202: Combustion-supporting gas analysis, i.e., determining whether the air contains combustion-supporting gas, such as oxygen, ozone, chlorine, fluorine and other oxidants;

[0065] Step S203: Ignition source analysis to determine whether there is an ignition source such as open flame, friction spark, high temperature hot surface, electrical spark, static discharge, lightning, etc.;

[0066] Step S204: Dust cloud analysis to determine whether the dust is in a suspended state. Use air quality monitoring instruments to determine whether a dust cloud is formed in the environment based on the principle of laser scattering, electrical signals, and temperature changes, and measure the dust cloud suspension concentration. When the dust cloud suspension concentration is greater than the lower explosion concentration of the process dust and less than the upper explosion concentration, it indicates that the dust cloud is in a flammable state;

[0067] Step S205: Space airtightness analysis. Lack of gas exchange will increase the risk of accidents such as fire or explosion. Determine whether the space where the process dust is located has no good ventilation and exhaust protection measures and has the ability to hinder the circulation of gas, process dust (or liquid). If so, it is a relatively closed space;

[0068] Step S3: Differentiate the types of buildings in the explosion-related area. Buildings include buildings and structures. The differentiation steps are as follows:

[0069] Step S301: Determine whether the building in the explosion-prone area has an operating post. If the building in the explosion-prone area has an operating post, the building is determined to be a building; otherwise, proceed to the next step S302.

[0070] Step S302: Determine whether the building function in the explosion-prone area is single. If the building function in the explosion-prone area is single, the building in the explosion-prone area is determined to be a structure; otherwise, proceed to the next step S303.

[0071] Step S303: Determine whether the building area of ​​the building in the explosion-related area is less than or equal to half of the maximum allowable building area of ​​the fire partition in the "Code for Design of Building Fire Protection" (GB50016-2014), and whether the number of mobile operation posts (inspections) during normal production is less than 3 people.

[0072] If the building area of ​​a building in an explosion-prone area is less than or equal to half of the maximum allowable building area of ​​a fire compartment in the building fire protection design specification, and the number of people in a normal production mobile operation post (inspection) is less than 3, the building in the explosion-prone area is determined to be a structure;

[0073] Otherwise, the buildings in the explosion-related areas are judged as buildings. (Note: The number of people in the mobile operation post (inspection) is less than 3 only refers to the limit on the number of people in the normal production process, and there is no limit on the number of people during shutdown and maintenance).

[0074] Step S4: Determine the fire hazard of buildings in dust explosion-prone areas. The fire hazard includes fire hazard level and fire resistance level. The purpose is to confirm the maximum number of floors allowed for buildings in the divided fire zones and the maximum allowable building area of ​​the fire zones. The steps are as follows:

[0075] Step S401: According to Table 1 and Table 2, the fire hazard level and fire resistance level of the building are obtained, wherein Table 1 is a classification table of fire hazard levels of items stored in a building, and Table 2 is a standard table for judging the fire resistance level of a building (the numbers in Table 2 are the combustion and fire resistance time of components, in h). The fire resistance level of the building is judged from level 1 to level 4 in sequence, and the highest level when the combustion and fire resistance time of all components of the building meet the requirements is the fire resistance level of the building;

[0076] Table 1

[0077]

[0078]

[0079] Table 2

[0080]

[0081]

[0082] Step S402: According to the fire hazard level and fire resistance level of the building, confirm the maximum allowable number of floors and the maximum allowable building area of ​​the fire compartment according to Table 3. Table 3 is a reference table for the maximum allowable building area of ​​the fire compartment. "Not allowed" in Table 3 means that the corresponding column header is not allowed, for example, multi-story factories are not allowed, high-rise factories are not allowed, and underground or semi-underground factories are not allowed.

[0083] Table 3

[0084]

[0085]

[0086] Step S5: Determine whether there are major production safety accident hazards in the explosion-related area, that is, determine whether there are situations in the site:

[0087] "Different types of combustible dust, combustible dust and combustible gas and other media that are likely to increase the risk of explosion share a dust removal system, or different buildings (structures) and different fire protection zones share a dust removal system, and the dust removal systems are interconnected." Specifically, determine whether the following five situations exist. If so, it will be determined as a major production safety accident hazard.

[0088] 1) If a process dust that is combustible dust is mixed with another process dust to produce a reaction that intensifies the explosion hazard, and they share a dust removal system, there is a major production safety accident hazard in the explosion-related area;

[0089] 2) If the process dust of combustible dust is mixed with combustible gas (including steam) and shares a dust removal system, there is a major hidden danger of production safety accidents in the explosion-related area;

[0090] 3) If two or more independent buildings share a dust removal system, there is a major production safety accident hazard in the explosion-related area;

[0091] 4) If the dust-generating points in different fire zones of the same building share a dust removal system, there will be a major hidden danger of production safety accidents in the explosion-related areas;

[0092] 5) If the dust removal systems of different structures are interconnected through dust removal ducts, fans, and air outlet ducts, or if the dust removal systems of different fire protection zones are interconnected through dust removal ducts, fans, and air outlet ducts, there will be major production safety accident hazards in explosion-related areas.

[0093] If any of the following four situations exist, it will not be considered as a major production safety accident hazard:

[0094] 6) Due to production process reasons, process dust and combustible gas coexist and accompany each other in the same part of the seat;

[0095] 7) Due to production process requirements, the dust removal system of starch, feed processing and other enterprises vertically crosses different fire protection zones but is independently set up according to the process flow;

[0096] 8) The dust removal systems of two or more fire zones are equipped with air-locking ash unloading devices and are interconnected through ash conveying pipelines;

[0097] 9) The dust removal system fans of two or more fire compartments share one exhaust chimney.

[0098] Step S6: Formulate fire zone division principles:

[0099] (1) Different buildings cannot be divided into one fire zone; (2) Buildings and structures cannot be divided into one fire zone; (3) Interconnected structures can be divided into one fire zone; (4) Fire separations should be used between fire zones; (5) The maximum allowable building area of ​​a fire zone meets Table 3.

[0100] Step S7: For areas with major production safety accident hazards, a fire zoning plan is issued based on the fire zoning principle and engineering examples;

[0101] In one embodiment, the process dust (combustible dust) in the explosion-related area is a mixture of coke powder and coal powder, and the explosion pressure ratio (PR) is measured to be 3.9792, which is determined to be explosive dust; for the production process in the explosion-related area, the five basic elements for dust explosion are all present for a long time; it is determined that the fire hazard level of the buildings in the explosion-related area is Class C, the fire resistance level is Class II, and the building is a single-story factory building. According to Table 3, the maximum allowable building area of ​​the fire protection zone in this area cannot exceed 8000m 2 .

[0102] 1) T4 transfer station is a structure, while circular stockyard No. 5 coal bunker and circular stockyard No. 6 coal bunker are different buildings; 2) T2 transfer station and T3 transfer station are structures, while circular stockyard No. 1 coal bunker, circular stockyard No. 2 coal bunker, circular stockyard No. 3 coal bunker and circular stockyard No. 4 coal bunker are different buildings. This design meets the judgment situation: 5) If the dust removal systems of different buildings and structures and different fire protection zones are connected through dust removal ducts, fans, and air outlet pipes.

[0103] After the above judgment, according to the division principle, a fire zone division plan is issued, such as Figure 3 As shown:

[0104] Fire partition (a): The underground belt corridor from No. 5 and No. 6 coal bunkers in the circular material yard to the T4 transfer station, the underground and ground belt corridors from the T4 transfer station to the T3 transfer station, and the T4 transfer station are divided into one fire partition. The maximum allowable building area of ​​the fire partition shall not exceed 8000m 2 ;

[0105] Fire partition (b): The underground belt corridors from T2 transfer station, T3 transfer station, No. 1 and No. 2 coal bunkers of the circular material yard to T2 transfer station, the underground belt corridors from No. 3 and No. 4 coal bunkers of the circular material yard to T3 transfer station, and the above-ground and underground belt corridors from T2 transfer station to T3 transfer station are divided into one fire partition. The maximum allowable building area of ​​the fire partition shall not exceed 8,000 m 2 ;

[0106] Step S8: For areas with major production safety accident hazards, based on the fire zoning principles and combined with engineering examples, a fire separation plan between fire zones is issued. The specific steps are as follows:

[0107] Step S801: Select a fire separation scheme between fire partitions that is suitable for the actual working conditions of the working environment, such as fire walls, fire doors, fire glass, fire partitions, fire shutters, fire water curtains, etc., to ensure that the selected method can effectively delay the spread of fire during dangerous times and does not affect normal production activities during safe times.

[0108] 1) Firewall: Set up walls with good fire resistance inside the building to effectively isolate different fire protection areas and delay the spread of fire when a fire occurs;

[0109] 2) Fire doors: Fire doors are installed between the doors leading to different fire compartments. These doors are kept closed under normal circumstances and automatically close when a fire occurs, effectively isolating smoke and burning substances;

[0110] 3) Fireproof glass: For fire partitions that need to maintain transparency and good vision, such as corridors, stairwells, tourist areas, etc., fireproof glass can be used to construct fire partitions;

[0111] 4) Fire partition: A partition made of fire-resistant material is set horizontally or vertically to divide a fire partition area into multiple small areas;

[0112] 5) Fireproof water curtain: When there is a need to set up fire separation, but it is not convenient to set up fire walls, fire curtains and other separation measures between fire partitions, such as production lines that cannot be interrupted in industrial plants, special process requirements such as the need for material transportation that make it impossible to set up fire walls, etc., fireproof water curtains are used instead of fire walls for separation.

[0113] Step S802: After the fire partition is installed, select a sealing material that is certified and meets fire protection standards, such as high temperature fireproof glue, silicone sealant or polyurethane foam, etc. to seal the fire partition, and use professional tools (such as spray guns, scrapers, etc.) to evenly fill the selected sealing material into all joints and cracks. Fill in place without bubbles and make the surface smooth. For larger gaps, you can first use fillers (such as asbestos or glass fiber) to pre-fill, and then apply sealing materials to ensure that no smoke can penetrate, and ensure that all ventilation holes, switches and sockets that are connected to the outside world can operate normally.

[0114] Step S803: Before putting it into use, validity verification must be performed.

[0115] 1) Use thermal imaging cameras to detect temperature differences inside and outside the fire compartment. If there are unsealed areas, heat loss may occur, thus showing different temperature patterns;

[0116] 2) Use a smoke generator to conduct a leak test. Generate a certain concentration of colored harmless gas in the separation area between the fire partitions, and then test whether there is gas overflowing through the separation area.

[0117] 3) Mix clean water and detergent and spray them on the joints of each fire partition. If foam is formed, it may indicate a leak. This method is suitable for detecting larger gaps.

[0118] Step S804: Regularly inspect and maintain the fire separation of the fire partition to ensure normal operation and long-term effectiveness.

[0119] The present invention provides a method for dividing fire zoning in a dust explosion hazardous area. The division steps and the final fire zoning results meet the requirements of various standards and specifications. The main standards and specifications involved are "Fire Protection Design Standard for Iron and Steel Metallurgical Enterprises" (GB50414-2018), "Code for Fire Protection Design of Buildings" (GB50016-2014), "General Code for Fire Protection of Buildings" (GB55037-2022), etc.

[0120] It should be noted that the embodiments described in the present invention are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the described embodiments or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the attached claims.

Claims

1. A method for dividing fire zones in dust explosion hazardous areas, characterized in that: The following steps are included: Step S1: Conducting explosive screening test on process dust in the explosion-related area; Step S2: Conduct explosion risk analysis on process dust in the explosion-related area; Step S3: distinguishing the types of buildings in the explosion-related area, where buildings include buildings and structures; Step S4: Determine the fire hazard of buildings in dust explosion-prone areas. The fire hazard includes fire hazard level and fire resistance level. According to the fire hazard level and fire resistance level, determine the maximum number of floors allowed for buildings in fire zones and the maximum allowable building area of ​​fire zones. Step S5: Determine whether there are any major production safety accident hazards in the explosion-related area; Step S6: Formulate fire protection zoning principles; Step S7: For areas with major production safety accident hazards, determine a fire zoning plan based on the fire zoning principle; Step S8: Determine the fire separation scheme between fire partitions.

2. A method for dividing fire zones in dust explosion hazardous areas according to claim 1, characterized in that: The explosive screening test of process dust in the explosion-prone area includes: Step S101: In a single test, the maximum value of the explosion pressure of the process dust in the explosion test device is recorded as P ex,a ; Step S102: The pressure of the process dust when it is detonated by the chemical ignition device in the explosion test device is recorded as P ignition ; Step S103: After the process dust is detonated by a chemical igniter under atmospheric pressure, the pressure rise value of the explosion in the explosion test device is recorded as ΔP ignitor ; Step S104: The explosion pressure ratio is recorded as PR, PR = (P ex,a -ΔP ignitor ) / P ignition ; If the calculated explosion pressure ratio PR is greater than or equal to 2, the process dust is explosive dust; otherwise, the process dust is non-explosive dust.

3. The method for dividing fire zones in dust explosion hazardous areas according to claim 1 is characterized in that: The explosion risk analysis of process dust in explosion-prone areas includes: analyzing whether the five elements necessary for dust explosion are simultaneously present in the explosion-prone areas, including: the presence of combustion-supporting gas, the process dust being explosive dust, the presence of an ignition source, a dust cloud within the explosive concentration range, and the process dust being located in a relatively closed space.

4. The method for dividing fire zones in dust explosion hazardous areas according to claim 1 is characterized in that: The method of distinguishing the types of buildings in the explosion-prone area includes the following steps: Step S301: If the building in the explosion-related area has an operating post, the building is determined to be a building; otherwise, proceed to the next step S302; Step S302: If the building in the explosion-prone area has a single function, the building in the explosion-prone area is determined to be a structure; otherwise, proceed to the next step S303; Step S303: If the building area of ​​the building in the explosion-prone area is less than or equal to half of the maximum allowable building area of ​​the fire protection zone in the building fire protection design specification, and the number of normal production mobile operation posts is less than 3 people, the building in the explosion-prone area is determined to be a structure; Otherwise, the buildings in the explosion-prone areas are judged as structures.

5. The method for dividing fire zones in dust explosion hazardous areas according to claim 1 is characterized by: The determination of whether there is a major hidden danger of production safety accident in the explosion-related area includes the following steps: If a process dust that is combustible dust is mixed with another process dust to produce a reaction that exacerbates the risk of explosion, and they share a dust removal system, there is a major potential for production safety accidents in the explosion-related area; If process dust of combustible dust is mixed with combustible gas and shares a dust removal system, there is a major potential risk of production safety accidents in the explosion-related area; If two or more independent buildings share a dust removal system for dust-generating points, there will be a major production safety accident hazard in the explosion-related area; If dust-generating points in different fire zones of the same building share a dust removal system, there will be a major hidden danger of production safety accidents in the explosion-related areas; If the dust removal systems of different buildings and structures are interconnected through dust removal ducts, fans, and air outlet ducts, or if the dust removal systems of different fire protection zones are interconnected through dust removal ducts, fans, and air outlet ducts, there will be a major potential safety hazard in production safety accidents in the explosion-related areas.

6. The method for dividing fire zones in dust explosion hazardous areas according to claim 1 is characterized by: The maximum allowable building area of ​​the fire compartment is based on the fire hazard level and the fire resistance level, and the maximum allowable number of floors is limited. The maximum allowable building area of ​​single-story factories, multi-story factories, high-rise factories, and underground or semi-underground factories is further determined under the conditions of fire hazard level, fire resistance level, and maximum allowable number of floors.

7. The method for dividing fire zones in dust explosion hazardous areas according to claim 1, characterized in that: The fire zoning principles include: Different buildings cannot be divided into one fire zone; Buildings and structures cannot be divided into one fire zone; Interconnected structures can be divided into one fire zone; Fire separations should be used between fire compartments; The maximum allowable building area of ​​the fire compartment meets the maximum allowable building area of ​​the fire compartment determined in step S4.

8. The method for dividing fire zones in dust explosion hazardous areas according to claim 1, characterized in that: The fire separations between the fire compartments include fire walls, fire doors, fire glass, fire partitions, fire rolling curtains and fire water curtains.

Images