Which kind of central air-conditioning ventilation duct is better?
Thin steel plate is the main material for manufacturing ventilation ducts and components. Ordinary thin plates and galvanized steel plates are commonly used. The specifications are expressed as short side, long side and thick. The thickness of the commonly used thin plate is 0.5 × 4mm, and the specifications are 900mm × 1800mm and 1000mm × 2000mm.
The thin steel plates used to manufacture air ducts and pipe fittings require smooth and smooth surfaces, uniform thickness, no cracks and scars, and should be properly preserved to prevent rust.
(1) Ordinary sheet
Ordinary thin steel plate has two kinds of thin plate and coil. This kind of steel plate belongs to the category B steel plate, which is a cold rolled hot rolled steel plate of Q235B steel, which has good processing performance and high mechanical strength, and is inexpensive.
(2) Galvanized steel sheet
The thickness of galvanized steel sheet is generally 0.5 × 1MM. The length and width of the galvanized steel plate are the same as the ordinary thin steel plate, which is 5mm. The surface of the galvanized steel sheet has a protective layer to prevent corrosion, and generally does not require painting. The requirement for this kind of steel plate is that the surface is smooth and clean, and the thickness of the galvanized layer should not be less than 0.02 mm. It is mainly used for acid and moisture proof wind pipe systems, and the effect is better.
(I) Stainless steel plate
1 It has high plasticity, toughness, mechanical strength and corrosion resistance. It is a stainless steel commonly used in chemical corrosion-resistant duct systems.
2 The main element of stainless steel is chromium, which has high chemical stability. A passivation film is formed on the surface to protect the steel plate from oxidation and improve its corrosion resistance.
(3) Stainless steel is easy to bend during cold working, and it will cause internal stress and uneven deformation during hammering, thereby reducing the toughness of the stainless steel plate, increasing its strength, and making it brittle and hard.
(4) When stainless steel is heated to 450 ℃ ~ 850 ℃, the steel will deteriorate, harden and crack after slow cooling.
(2) Aluminum plate
1 Aluminum plates include pure aluminum plates and alloy aluminum plates, which are mainly used in chemical ventilation projects.
2 Aluminum plate has the advantages of beautiful color, low density, good plasticity and strong acid resistance, but it is easily corroded by hydrochloric acid and alkali and has good chemical corrosion performance.
(3) Aluminum alloy aluminum plates have high mechanical strength and poor corrosion resistance. Most of the aluminum plates used in ventilation engineering are pure aluminum plates and annealed aluminum alloy plates.
Because the aluminum plate is soft, there is no spark in the collision, so it is mainly used as a ventilation duct with explosion-proof requirements.
3. Plastic composite board
If you paste or spray a layer of plastic film on the ordinary steel plate, you will become a plastic composite steel plate. It is characterized by corrosion resistance, bending, biting, drilling and other processing performance.
Plastic composite steel plates are commonly used in air cleaning systems and ventilation and air conditioning systems with temperatures ranging from -10 ° C to 70 ° C.
The specifications of plastic composite steel plate are: 450mm × 1800 mm, 500 mm × 2000 mm, thickness 0.35≤, 0.7mm≤1000 mm × 2000 mm, thickness 0.8 ~ 2.0mm, etc.
