Calculation Model of Ventilation Times of Ventilation System in Production Workshop?

Ventilation Rate Calculation Model of Ventilation System in Production Workshop

in the chemical industry, air quality in the production floor is directly related to production efficiency, employee health and equipment safety. The ventilation system is one of the important facilities to ensure the air quality of the workshop. As the core parameter of ventilation system design and operation, the number of air changes directly affects the air quality control effect of the workshop. This paper will analyze in detail the "calculation model of the ventilation rate of the ventilation system in the production workshop" and discuss its importance in practical application.

1. ventilation frequency definition and importance

The number of air changes refers to the number of times the workshop air is completely replaced per unit time. Specifically, the number of air changes = ventilation/workshop volume. The number of air changes directly affects the air quality in the workshop. In chemical production workshops, due to the possible involvement of toxic and harmful gases, dust or other pollutants, a reasonable number of air changes is an important guarantee to ensure that the concentration of pollutants is lower than the safety standard.

The calculation of the number of air changes needs to consider the production process, pollutant characteristics, workshop layout and personnel density and other factors. Too low air exchange rate may lead to the accumulation of pollutants, affecting the health of employees and product quality, while too high air exchange rate will increase energy consumption and increase operating costs.

2. ventilation rate influencing factors

1. Workshop volume The number of air changes is inversely proportional to the volume of the workshop. Larger workshops require higher air exchange rates to ensure the timely discharge of pollutants. Therefore, when calculating the number of air changes, it is first necessary to accurately measure the length, width and height of the workshop and calculate its total volume.

2. pollutant concentration Different production processes will produce different kinds of pollutants, and the degree of harm to the human body and the discharge rate are also different. For highly toxic or highly concentrated contaminants, higher air changes are typically required to dilute and expel the contaminants. For example, some chemical plants may require more than 10 air changes per hour.

3. Production process requirements The type and intensity of the production process directly affect the calculation of the number of air changes. For example, certain reaction processes require strict control of humidity and temperature, which may place additional demands on the design of the ventilation system. The start-up and operating state of the equipment will also affect the emission rate of pollutants.

4. Personnel density The number of people in the workshop and the intensity of the activity will also affect the calculation of the number of air changes. Human respiration increases carbon dioxide concentrations, while human activity may generate heat and moisture, which need to be regulated by ventilation.

5. Equipment and Energy Efficiency When calculating the number of air changes, the efficiency and energy consumption of the ventilation equipment also need to be considered. For example, the use of high-efficiency blowers or return blowers can increase the efficiency of air displacement, thereby reducing the number of air changes required.

3. ventilation rate calculation model

1. basic calculation formula The formula for the number of air changes N is: N = ventilation (m³/h) /workshop volume (m³) Ventilation can be calculated by duct diameter, wind speed and equipment efficiency, and the workshop volume needs to be determined according to actual measurement data.

2. pollutant concentration derivation model If the emission rate of pollutants and the target concentration in the workshop are known, the required number of air changes can be calculated using the following formula: N = (discharge rate × maximum allowable concentration)/concentration after dilution × ventilation efficiency

3. dynamic model For a dynamically changing production environment, a dynamic model can be used to calculate the number of air changes. The model considers the diffusion and attenuation process of pollutants in the workshop, and is suitable for scenarios that require real-time monitoring and adjustment of air exchange rates.

4. practical application cases

Taking a chemical workshop as an example, assuming that the workshop volume is 2000 m³, the target pollutant concentration is 1 ppm, and the pollutant emission rate is 500 g/h. According to the calculation model, the number of air changes N is about 6 times/h. Through the actual operation test, it is found that the concentration of pollutants is controlled within the safe range, which shows the validity of the calculation model.

5. conclusion

"Calculation model of ventilation rate of production workshop ventilation system" is an important tool to ensure the air quality of chemical workshop. By accurately calculating the number of air changes, companies can effectively control pollutants, protect employee health and product quality, and optimize energy consumption. In practical applications, it is recommended to select an appropriate calculation model based on the characteristics of the production process and the characteristics of pollutants, and to maintain and optimize the ventilation system regularly.

Reasonable design and operation of the ventilation system can not only improve production efficiency, but also reduce the operating costs of enterprises and achieve sustainable development.