This standard specifies the terminology and technical requirements for harmful substances in the air of heat treatment workshops. This standard applies to the limits of harmful substances in the air of workshops during heat treatment production. JB/T 5073-1991 Limits of harmful substances in the air of heat treatment workshops JB/T5073-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T5073-91
Limits of harmful substances in the air of heat treatment workshops Published on 1991-06-11
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Limits of harmful substances in the air of heat treatment workshops Subject content and scope of application
This standard specifies the terminology and technical requirements for harmful substances in the air of heat treatment workshops. This standard applies to the limits of harmful substances in the air of workshops during heat treatment production. 2 Reference Standards
TJ36 Industrial Enterprise Design Hygiene Standard
GBJ4. Trial Standard for Industrial "Three Wastes\Emissions" 3 Terms
3.1 Hazardous Substances
JB/T507391
Dust, gas, mist, etc. in the air, which are harmful to human health through the respiratory tract or contact with the skin and eyes. 3.2 Concentration of Hazardous Substances
The mass of harmful substances contained in a unit volume of workshop air is called the concentration of harmful substances. 3.3 Workplace
Refers to the place where one often or regularly stays in the process of observing, operating, and managing production. If the production operation is carried out in many places in the workshop, the entire workshop is the workplace.
3.4 ​​Maximum Allowable Concentration
Harmful substances in the air at the workplace The concentration of the substance should not exceed the value. 4 Technical requirements
4.1 The harmful substances in the air of the current heat treatment workshop are shown in Table 1. Table 1 Harmful substances in the air of the heat treatment workshop
High and medium channel salt bath
Chemical heat treatment processes such as carburizing, nitrogen nitriding, carbonitriding, nitrocarburizing, isothermal, graded annealing and tempering, low overflow salt bath cleaning, bluing, etc.
Sand blasting and shot peening, floating particle furnace, solid carbon retention, etc., tempering fat port
Chlorine, ammonium chloride and hydrochloric acid, organic and its compounds, ammonia hook carbon monoxide, ammonia, ammonium chloride and hydroxide, methanol, acetone, sheep, ammonia oxide hook, formamide, methane
Ammonia oxide
Acidic acid, sulfur dioxide, trichloroethylene, hydrochloric acid, acetone, benzene dust
Hydrocarbons in shaft smoke and others Harmful gases 4.2 Harmful substances in the air of the heat treatment workshop should be identified. The concentration of any harmful substance in the air of the workplace shall not exceed the provisions of Table 2.
Approved by the Ministry of Machinery and Electronics Industry on June 11, 1991 and implemented on July 1, 1992Www.bzxZ.net
JB/T5073---91
The maximum allowable concentration of carbon monoxide can be relaxed when the working time is short: within 1 hour of working time, it is allowed to reach 50mg/m3, within 0.5h it is allowed to reach 100mg/m3, and within 15~20min it is allowed to reach 200mg/m3*. When working repeatedly under the above conditions, there must be an interval of more than 2h between two operations.
Table 2 The maximum allowable concentrations of harmful substances in the air of heat treatment workshops are
Carbon monoxide
Hydroxysulphuric acid
Recommended (converted into NaOH)
Strong oxidizing agent (converted into NO,)
Hydrogen hydride and hydrocyanate (converted into HCN)
Hydrogen chloride and hydrochloric acid
Trichloroethylene
Chloride (converted into F)
Dimethylformamide
Zhen and its compounds
Note: 1) Toxic substances that are easily absorbed through the skin in addition to harming the human body through the respiratory tract. Maximum allowable concentration
2 (containing more than 10% free silicon dichloride)
1 (containing more than 80% dissociated silicon dioxide)
0.5 (recommended value)
4.3 The detection of harmful substances in the air of heat treatment workshops shall be carried out according to the method specified in TJ36 "Workshop Air Monitoring and Inspection Method". 4.4 For harmful substances in the air of heat treatment workshops not included in these regulations, the corresponding regulations shall be used as the basis. 4.5 The treatment and discharge of harmful substances in the air of workshops shall be carried out in accordance with the provisions of Chapter 2 of GBJ4. When the exhaust device discharges harmful substances with concentrations exceeding the standard, it shall be purified and discharged into the atmosphere only after reaching the standard. 4.6 During normal production, harmful substances in the air of the workshop shall be tested at least once a year. If the production conditions or auxiliary materials change, identification and detection shall be carried out in time.
4.7 The source of harmful substances shall be arranged on the downwind side of the mechanical ventilation equipment at the workplace. 4.8 Effective measures shall be taken for the source of highly toxic substances, and ventilation devices shall be reasonably installed. Circulating air shall not be used for air conditioning. 4.9 When several harmful substances are released into the air at the same time, the comprehensive ventilation volume shall be implemented in accordance with Article 34 of TJ36. 4.10 An emergency exhaust device shall be installed in the workshop to eliminate the excessive harmful substances that may suddenly be generated in the workshop. 4.11 The waste gas discharged from carburizing, carbonitriding, nitrocarburizing, etc. must be ignited. 5 Comprehensive Utilization
5.1 Hazardous substances in workshop air that can generate certain environmental, economic and social benefits should be actively developed and utilized. 5.2 New technologies should be used to purify and recycle harmful substances in workshop air to prevent re-pollution. Additional Notes:
This standard was proposed by the National Technical Committee for Heat Treatment Standardization. This standard was drafted by the Mechanical Industry Environmental Protection Technology Research Institute of the Ministry of Machinery and Electronics Industry, and the main drafters of this standard were Wang Jinhuan and Zhang Honglan. 2
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