Classification of Ventilation and Exhaust Pipeline Uses:
1. Air duct for purifying air conditioning system: galvanized sheet and stainless steel; (Fiberglass reinforced plastics and composite materials which may be polluted by dust sources are forbidden in use)
2. Air duct for central air conditioning system: galvanized sheet and coloured steel insulation sheet; (ventilation duct can be made of fiberglass reinforced plastics and composite materials)
3. Air duct for environmental control system: galvanized sheet and stainless steel; (plastics, fiberglass reinforced plastics, composite materials can be used)
4. Air duct for industrial ventilation system: steel plate, galvanized sheet; (Libo air duct. Plastic, FRP, composite materials can be used)
Note: FRP ducts can be divided into organic and inorganic materials. According to the design specifications, prohibited organic materials are required for fire protection.
5. Air ducts for special occasions: mine coated air ducts, mine plastic air ducts; (Require flame retardant and antistatic mine safety characteristics)
Three cleaning methods of ventilation and smoke exhaust equipment:
Chemical cleaning: Chemical cleaning pipeline is a temporary transformation of the pipeline using chemicals, and chemical cleaning is carried out from both ends of the pipeline by temporary pipeline and circulating pump station. The technology has the characteristics of flexibility, no requirement for pipe shape, fast speed and thorough cleaning.
High-pressure water cleaning: High-pressure water jet above 50 Mpa is used to peel off the dirt on the inner surface of the pipeline. This technology is mainly used for short distance pipeline, and the diameter of pipeline must be more than 50 cm. The technology has the characteristics of high speed and low cost.
PIG Pigging: PIG industrial pigging technology relies on the driving force generated by the pump to drive the PIG (Pigging Device) forward in the pipe, and discharges the dirt accumulated in the pipeline outside the pipe, so as to achieve the purpose of cleaning. This technology is widely used in various cleaning projects such as process pipelines and oil and gas pipelines in oil fields. Especially for long-distance pipeline cleaning, it has advantages that other technologies can not replace.