Industrial Ventilation System is a system that continually removes and supplies air to a particular area in a plant where a controlled environment is needed to eliminate physical hazards or maintain temperature and humidity conditions. Industrial ventilation systems usually include hoods that are mounted over work stations to capture hazardous fumes or dust; ducting, fans and an exhaust stack through which the contaminants are discharged; air cleaning devices; and a supply of heated or cooled fresh or outside air that replaces the exhausted contaminated air.
Ventilation is most effective when located at the source of contamination, known as local exhaust ventilation. This type of system typically features locally installed equipment, such as capture hoods, ducting, air cleaners and fans that can be operated at the emission source. Hoods should be mounted close to the work station, positioned so that workers are not between them and the emission source. The hoods should be capable of capturing the contaminants at the source with an air velocity high enough to prevent their recirculation into the worker’s breathing zone. The captured contaminants are then safely discharged through a high-velocity fan.
The design of the ducting is critical to the performance of any ventilation system. The ducting must be large enough to handle the maximum anticipated flow rate of the system without sacrificing efficiency. The ducting material should be durable and easy to maintain, such as smooth corrugated metal or lined fiberglass ductwork. Ducts should be designed to minimize the loss of airflow due to friction or bend losses. The duct design should also provide for a minimum of six diameters of straight duct at the inlet and three diameters of straight duct at the fan outlet. System effect losses are also important to consider.
Airflow is also impacted by changes in the size or location of any exhaust hood or fan or the addition of any branch ducts. Any modifications should be carefully planned to ensure that the ducts are “re balanced.” A rebalancing process can restore proper airflow and reduce energy costs by eliminating any dead spots in the system.
All ventilation systems deteriorate over time because of contaminant build-up within the system, especially in filters. Regular maintenance and testing are critical to ensuring long term system integrity.
There are two basic approaches to industrial ventilation: dilution and local exhaust. Dilution ventilation mixes the contaminated indoor air with clean or outdoor air to dilute the concentration of pollutants. Buildings with wall supply fans and rooftop exhaust fans are a common example of dilution ventilation. Local exhaust ventilation, on the other hand, consists of small, localised equipment (capture hoods, ducting, air cleansers and fans) that is placed directly over an emission source to capture and filter the contaminants right at the source and then discharges them outdoors.
Many textbooks, reference books and engineering books on industrial ventilation have not been updated in a couple of decades. This proposed new IVDGB will provide a single source for all recent research and best practice in the field of industrial ventilation for contaminant control. This will benefit researchers, engineers (design and plant), and scientists at all levels worldwide.