Polypropylene PP ductwork
PP ductwork introduction：
PP ductwork, also known as polypropylene plastic air duct, plastic ventilation duct. PP air ducts are usually used for the exhaust of corrosive exhaust gas in the environment of industrial plants, the exhaust of fume hoods in the laboratory, and the exhaust of VOC organic exhaust gas. The advantages of PP air ducts are light weight, acid and alkali corrosion resistance, hot melt welding with PP electrodes, and easy processing and installation of fittings such as elbows, flanges, tees, and reducing diameters. It is currently the most widely used in waste gas treatment in the environmental protection industry. a ventilation duct.
How PP ductwork works
PP ductwork is used in industrial exhaust air such as acid, alkali and organic waste gas. By installing an induced draft fan at the end, the polluted waste gas in the environment is drawn to the outdoor through the PP anti-corrosion fan. PP air ducts are usually divided into positive pressure air supply or negative pressure air extraction, and the inner wall is smooth and the resistance is small.
PP ductwork performance characteristics
- No rust: PP air duct can withstand the corrosion of PH value in a wide temperature range and high concentration of acid and alkali ranging from 1 to 14.
- Wear resistance and no scaling: The inner wall of PP air ducts and fittings is uniform and smooth, with low flow resistance and no scaling.
- Reduce vibration and noise: PP air duct has excellent sound insulation performance, which can significantly reduce vibration and noise caused by liquid flow.
- Anti-freeze cracking: The material used in PP air duct has excellent elasticity, so that the section of the pipe and pipe fittings can expand together with the frost heaving liquid without bursting.
- Anti-condensation and less heat loss: The material used in the PP air duct is a poor thermal conductor, which can reduce condensation and reduce heat loss.
- Simple installation: PP air duct is light in weight, easy to install and operate, and has weldability.
- Long service life: PP air duct has a service life of 50 years under the specified temperature, pressure, medium and other operating conditions.
- Excellent corrosion resistance: resistant to corrosion by most chemicals, and can withstand high concentrations of acids and alkalis with a pH range of 1-14 in a wide range.
- Good hygienic performance: There are only carbon and hydrogen elements in the molecular structure of PP air duct material, which is non-toxic and tasteless, and has reliable hygienic performance.
- Heat-resisting heat preservation and energy saving: The maximum operating temperature of PP air duct is about 70 degrees, and the thermal conductivity of this product is only 1200 of that of steel pipe, so it has better heat preservation performance.
PP ductwork system structure
In order to form a complete PP anti-corrosion pipeline system, in addition to PP air ducts, it is not enough to have PP air duct accessories, which can be combined with the installation to form a complete anti-corrosion acid and alkali-resistant exhaust air pipeline system.
PP ductwork accessories:
- PP elbow
- PP tee
- PP reducer
- PP flange
- PP casing
- PP damper
We collectively refer to the above products as PP air duct exhaust system
PP ductwork specification
There are two types of PP ductwork in terms of shape, one is a square PP duct, and the other is a round PP duct. In terms of application, the amount of circular shape is relatively large, and the circular PP air duct is easy to manufacture. The PP sheet can be rolled into a round pipe through a plate rolling machine. The labor and mechanical costs are relatively low, while the square PP air duct is made of PP sheet. Hot melt bending machine, folded four times at a 90-degree angle and then welded by a butt welding machine. There are many processes. Compared with the square tube with the same circumference or cross-section, the price of the square tube is higher, of course, it depends on the PP The wall thickness of the air duct and whether to strengthen the outer flange, etc.
PP air duct installation method
- PP air duct socket connection, that is, a PP sleeve is welded at the end of each air duct to facilitate the insertion of the next air duct;
- PP air duct and air duct flange connection, that is, a PP flange is welded at both ends of each air duct, and the screw-to-lock connection is used during installation.
The strengthening method of PP air duct, in industrial exhaust, in most cases, the end centrifugal fan is used to exhaust air, and the negative pressure is formed in the PP air duct, and the industry design specification stipulates the required wall thickness of the PP air duct at a certain wind speed. And the strengthening method, usually the PP air duct is reinforced by the outer flange, such as a 3-meter-long air duct, which is reinforced with 2 flanges, which is beautiful and durable. The large square air duct is reinforced by the outer flange, and the internal PP circular pipe is used for structural support.