Are there any examples of division of chemical units?

Read more safety evaluation books and safety evaluation reports made by others, and you will slowly learn it! Let me share with you an article about the division of evaluation units.: (1) Concept of evaluation unit The evaluation unit is based on the identification and analysis of dangerous and harmful factors, and according to the needs of the evaluation objectives and evaluation methods, the system is divided into limited and scope-determined evaluation units. A construction project or device (system) that is the object of evaluation is generally composed of several relatively independent and interrelated parts (subsystems, units). The functions of each part, the substances they contain, the existing risk factors and harmful factors, the dangers and hazards, and the safety indicators are all different. When implementing an evaluation with the entire system as the evaluation object, the evaluation object is generally divided into a number of units with a limited scope and a certain scope according to certain principles and the needs of the evaluation objectives and evaluation methods for evaluation respectively, and then integrated into the evaluation of the entire system. (2) Principles and methods of division of evaluation units The division of evaluation units generally combines the characteristics and characteristics of the production process, process equipment, and materials with the categories and distribution of dangerous and harmful factors. An evaluation unit can also be further divided into several sub-evaluation units or more detailed units according to the needs of the evaluation. The division of evaluation units does not require absolute consistency. Commonly used principles and methods for dividing evaluation units are as follows. (1) Divide evaluation units based on the categories of dangerous and harmful factors. 1) For the analysis and evaluation of dangerous and harmful factors in comprehensive aspects such as process plans, overall layout, natural conditions, and environmental impact on the system, the entire system can be used as an evaluation unit. 2) Classify places and devices with common risk factors and harmful factors into a unit. (2) Divide evaluation units based on device and material characteristics 1) Divide according to device process functions. 2) Relative independence division of connection arrangements. 3) Divide evaluation units according to process conditions. 4) Divide evaluation units according to the potential chemical energy, toxicity and quantity of dangerous goods stored and handled. 5) Based on past accident data, key equipment that can cause production shutdowns, have a large impact, and cause huge losses and injuries should be treated as a unit. ； Treat areas with high risk and high capital density as a unit ； Treat particularly hazardous areas and devices as a unit ； Combine units with similar hazardous potential into one larger unit. (3) Classification based on relevant specific provisions on evaluation methods. For example, ICI's Mond Fire, Explosion, and Toxicity Index Method requires the division of evaluation units based on material coefficients and fire, explosion, toxicity, and overall risk index before and after measures are taken during the operation, environment, or device. ； The fault hypothesis analysis method is divided into categories according to issues, such as electrical safety, fire protection, personnel safety and other issues. ； Another example is that the fuzzy comprehensive evaluation method requires dividing evaluation units from different angles (or different levels), and then making a comprehensive evaluation of things based on multiple constraints in each unit to establish each evaluation set.

The earliest definition of safety evaluation unit in my country comes from the "Guidelines for Pre-Evaluation of Occupational Safety and Health in Construction Projects (Engineering)" issued by the Ministry of Labor of the People's Republic of China, which defines an evaluation unit (unit of evaluation) as: a relatively independent operation area in terms of process and equipment layout that is delineated according to the requirements of the evaluation. In the specific safety evaluation process, because it breaks through the inherent risk range of only evaluating process equipment, the 1999 version of the "Construction Project (Engineering) Labor Safety and Health Pre-Evaluation Guidelines" made a supplementary definition: The evaluation unit is based on the analysis of dangerous and harmful factors, and according to the needs of the evaluation objectives and evaluation methods, the system is divided into a number of units that are limited, have a certain scope and need to be evaluated. In addition, the "Safety Pre-Assessment Guidelines" ( * * The definition of evaluation unit in Article 3.5 of the Work Safety Supervision Bureau 2003 is: For the purpose of safety evaluation, the evaluation unit divides the production process or site into several relatively independent parts according to the characteristics of the production process or site of the construction project. The "Guidelines for Safety Assessment of Hazardous Chemical Production Enterprises (Trial)" defines the evaluation unit as: According to the actual situation of the evaluated unit and the needs of safety evaluation, the evaluated object is divided into some relatively independent parts for safety evaluation, and each relatively independent part is called an evaluation unit. The definition of evaluation unit in the "Guidelines for Safety Assessment of Non-Coal Mines" is: According to the needs of the evaluation work, units are divided according to the production process function, production equipment, relative spatial position of the equipment, categories of dangerous and harmful factors, and accident scope. The evaluation unit should be relatively independent and have obvious characteristic boundaries to facilitate the identification, analysis and risk assessment of dangerous and harmful factors. The definition of evaluation unit in the "Guidelines for Coal Mine Safety Assessment" is: For coal mine construction projects (or coal mines) with complex production systems, for the purpose of safety evaluation, evaluation units can be divided according to safety production systems, mining levels, production process functions, production sites, categories of dangerous and harmful factors, etc. The evaluation unit should be relatively independent, facilitate the identification and risk assessment of hazards and harmful factors, and have obvious characteristic boundaries. The definition of evaluation unit in the "Guidelines for Safety Assessment of the Onshore Oil and Gas Exploration Industry" is: Based on the identification and analysis of dangerous and harmful factors, and according to the needs of the evaluation, the evaluation objects are divided into evaluation units according to the oil and gas production process functions, relative spatial positions of production facilities and equipment, categories of dangerous and harmful factors, and accident scopes, so that the evaluation units are relatively independent and have obvious characteristic boundaries. According to the definitions of administrative documents issued one after another in recent years, there are indeed certain deviations in the expression, but the definitions of safety evaluation units in the "Guidelines for Pre-Evaluation of Labor Safety and Health in Construction Projects (Projects)" and "Guidelines for Pre-Evaluation of Labor Safety and Health in Construction Projects (Projects)" are basically used. Among them, the definitions in early documents tended to only emphasize the evaluation of the inherent risks of process equipment and production sites. With the extension of the evaluation scope and the improvement of evaluation requirements, it is gradually emphasized that the scope of the evaluation unit should be reasonably extended according to the needs of the evaluation objectives and evaluation methods. I think a more appropriate definition of evaluation unit is: According to the needs of the evaluation objectives and evaluation methods, the system is divided into a number of limited, relatively independent units with a certain scope and needs to be evaluated according to the process flow, production site, hazard and harmful factor categories, etc.

According to the "Detailed Rules for Safety Assessment of Hazardous Chemical Construction Projects (Trial)" (Work Safety Supervision Bureau [2007] No. 255), the external safety conditions, general layout, main devices (facilities), and public works of the construction project can generally be divided into evaluation units.

It is simple and feasible to classify according to the "Detailed Rules for Safety Assessment of Hazardous Chemical Construction Projects (Trial)" (Work Safety Director Hazardous Chemicals [2007] No. 255)

Thank you all heroes. . I will study hard in the future * of. .