Understanding of the concept of “adequate ventilation”?
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SYT10041 states that adequate ventilation means that the ventilation conditions (natural or artificial) are sufficient to prevent the accumulation of large amounts of oil vapors or combustible gas mixtures, so as to keep their concentration below 25% of their lower flammability (explosion) limit. It seems difficult to apply this definition in practical work; could someone give some guidance? Thank you.
Section 5.5.2.2 of the \"AQ3013-2008 General Specifications for Safety Standardization in Enterprises Handling Hazardous Chemicals\" stipulates that enterprises must ensure that their safety facilities are equipped in compliance with relevant regulations and standards. It is advisable to install fixed detection and alarm systems for flammable, explosive, and toxic gases in such areas, in accordance with SH3063; the alarm signals should be sent to the control rooms or operation rooms of process units and storage and transportation facilities. In other words, to achieve “adequate ventilation,” one can refer to the data displayed by the combustible gas alarm.
Upstairs, why rely on AQ3013? Safety standardization isn’t mandatory anyway.
In AQ3013-2008, Chapters 4 and 5 of this standard are mandatory provisions. It should be almost mandatory by now
\"Code for Design of Electrical Installations in Explosive and Flammable Atmospheres\": Adequate ventilation = Good ventilation: In explosive hazard areas, ventilation is considered to be good when the air flow rate is sufficient to dilute flammable substances rapidly to below 25% of their lower explosive limit. I have no experience in design; I think it’s possible to calculate the volatilization rate for this purpose, or to determine the ventilation capacity based on existing experience.
The above focuses only on the aspect of explosions; should adequate ventilation of toxic gases for workshop workers also be considered? In that case, should workshop air standards be used as a guide?
Personally, I think it can be determined based on the alarm threshold for flammable and toxic gases.
Personally, it’s difficult to determine what constitutes adequate ventilation – there are no clear criteria or rules for judging this. I hope some experienced experts can share their insights on this matter. Thank you.
There are indeed no clear indicators or rules for determining adequate ventilation. In my opinion, one can check whether the environment allows for natural ventilation, with no structures blocking airflow and causing localized areas of poor ventilation. In situations where low air pressure makes air circulation difficult, mechanical ventilation can be considered, and the readings from alarms can be used as a reference.
In my opinion, as long as the oxygen level detection alarm and the combustible gas leak alarm do not trigger, and the concentration of toxic and harmful substances in the workshop is within acceptable limits, then ventilation is sufficient
Many of the responses mentioned that it is possible to make judgments during the production phase with the help of measuring tools, but it is difficult to do so during the design phase. Generally, the classification of hazardous areas is carried out during the design stage; therefore, there are no measuring tools or alarm devices available. Is it possible to rely on experience for such judgments?
LZ: What’s not easy to understand about this?
Based on my many years of experience in managing safety in chemical production, a good level of ventilation is defined by the absence of any odor of solvents at the work site. Using instrument measurements as a standard is not economical nor practical. In general, whenever an odor is detected, it is necessary to strengthen control over fire sources and identify the source of the leakage.
Personally, I think it can be understood from the definition of safe production; adequate ventilation refers to the level of ventilation necessary to ensure safe production. Both occupational hazards and the lower explosion limit need to be taken into account.
Good ventilation: In areas at risk of explosion, ventilation is considered good if the air flow rate is sufficient to dilute flammable substances quickly to below 25% of their lower explosive limit. I have no experience in design; I think it’s possible to calculate the volatilization rate for this purpose, or to determine the ventilation capacity based on existing experience. The \"Code for Safety and Health Design in Industrial Enterprises\" requires that, based on the production processes as well as the characteristics of dusts and toxins, ventilation measures to prevent their spread should be implemented, so as to keep the concentration of harmful substances in the workplace below the \"Occupational Exposure Limits for Hazardous Factors in the Workplace\". When vapors of several solvents (benzene and its homologs, alcohols, or acetates) or several irritating gases (sulfur trioxide and sulfur dioxide, hydrogen fluoride and its salts, etc.) are released into the air simultaneously, the total volume of air required for thorough ventilation should be calculated as the sum of the amounts of air needed to dilute each type of gas to its specified exposure limit. In workshops equipped with hot air heating and air conditioning, the fresh air inlets should be located in areas with clean air, and the amount of fresh air supplied should meet the standard requirement of 30 m3/h per person. The \"Code for Design of Heating, Ventilation and Air Conditioning\" (GBJ 19) stipulates that: \"The fresh air volume of the air conditioning system shall comply with the following requirements: For production workshops, it shall be determined based on the maximum value required to compensate for exhaust air, maintain a positive pressure inside the room, or ensure a fresh air volume of not less than 30 m3/h per person.\"