To know more about air ducts

--- What is an air duct and what types of common air ducts are there?

The air duct mainly refers to the ventilation duct of the central air conditioning system. It is often overlooked, but it is an important part of the air conditioning system. The air duct is made of thin steel plate, aluminum plate, hard polyvinyl chloride plate, glass fiber reinforced plastic and other composite materials. It is a general term for various pipes used to transport air and air mixture.

1. According to the material, it can be divided into: metal duct, non-metal duct.

Among them: (1) Metal air ducts can be divided into: steel plate air ducts, aluminum plate air ducts, stainless steel air ducts, etc.; (2) Non-metallic air ducts can be divided into: rigid PVC air ducts, plexiglass air ducts, inorganic air ducts, etc. Glass ducts, FRP ducts and other composite ducts, etc.;

2. According to the shape of the air duct, it can be divided into: circular air duct and rectangular air duct;

3. According to the working pressure of the ventilation and air-conditioning system, it can be divided into three categories: high-pressure air duct, medium-pressure air duct and low-pressure air duct.

--- What are the main equipment

1. Mechanical equipment:

Shearing machine, vibration shearing machine, electric shear, manual folding machine, three-roll rounding machine, combined punching and shearing machine, flange rounding machine, box-type combined single-flat bite machine, hand scissors, round elbow bite Mouth machine, rib and gap dual-purpose machine, insert forming machine, electric riveting gun, electric welding machine, electric angle grinder, bench drill, grinding wheel cutting machine, hand electric drill, punching machine, air compressor and paint spray gun etc.

The double-sided aluminum foil insulation board air duct also needs the following tools: male and female knives, round-hole chisel knives, moon knives, electric irons, manual slotting tools, binding grabs, etc.

2. Measurement and inspection tools:

Vernier caliper, steel ruler, steel tape measure, vernier universal angle ruler, inner caliper, air leakage test device, etc.

Note: With the development of science and technology, there are more and more types and models of construction equipment, and the equipment of construction equipment should be reasonably configured according to the project nature, construction conditions and design drawings.

3. Equipment entering the construction site must be inspected and accepted, and regularly maintained.

--- What are the requirements for the working conditions of air duct production?

1. There should be an independent work site for the prefabrication of the air duct, the site should be flat and clean, and the processing platform should be leveled. The site of the double-sided aluminum foil insulation board air duct and other composite material air ducts should be dry, and there should be enough storage space for finished products;

2. The work site should have construction equipment and material stacking sites, and facilities and power sources should have reliable safety protection devices. The road at the work site should be clear. There must be all kinds of equipment and facilities that can meet the fire protection requirements;

3. When the processing equipment is arranged in the building, the bearing capacity of the floor and beams of the building should be considered, and corresponding measures should be taken if necessary;

4. The large-scale drawings and system drawings have been reviewed to meet the requirements, and technical and safety disclosures have been made;

5. For the air duct production of the clean system, there should be a clean and closed warehouse to store finished products or semi-finished products;

6. The processing site should reserve the transportation channel for on-site materials, finished products and semi-finished products, and the selection of the processing site should not hinder the fire channel.

--- What are the regulations for the reinforcement of metal air ducts?

1. Reinforcement measures should be taken if the diameter of circular air ducts (excluding spiral air ducts) is greater than or equal to 8 mm, and the length of the pipe section is greater than 1250 mm or the total surface area is greater than 4 m²;

2. The side length of the rectangular air duct is greater than 630 mm, the side length of the insulating air ductis greater than 800 mm, the length of the pipe section is greater than 1250 mm, or the unilateral area of the low-pressure air duct is greater than 1.2 m², and the medium-pressure and high-pressure air ducts are greater than 1.0 m², all should be reinforced. measure;

3. The reinforcement of irregular elliptical air ducts should be carried out with reference to rectangular air ducts;

4. The reinforcement of the air duct can be in the form of corrugated bar, vertical bar, angle steel (internal and external reinforcement), flat steel, reinforcing bar and inner pipe support;

5. For the reinforcement of corrugated bars or corrugated lines, the arrangement should be regular, the interval should be uniform, and the board surface should not have obvious deformation;

6. The reinforcement of angle steel and reinforcing bars should be arranged neatly, evenly and symmetrically, and its height should be less than or equal to the flange width of the air duct. The riveting of angle steel, reinforcing bars and air ducts should be firm and evenly spaced. It should not be larger than 220 mm, and the intersection should be connected as a whole;

7. The inner support of the pipe and the air pipe should be fixed firmly, and the spacing between the support points or the edge of the air pipe or the flange should be uniform, and should not be greater than 950 mm;

8. When the length of the air duct section of the medium and high pressure system is greater than 1250 mm, a reinforcement frame shall be provided for reinforcement. The single bite seam of the metal air duct of the high-pressure system should also have reinforcement or reinforcement measures to prevent the bite seam from bursting.

--- What are the regulations for metal air duct connections, and how to choose flanges and bolts

1. Requirements for the connection of metal air ducts:

(1) The bite seam of the splicing of the air duct plates should be staggered, and there should be no cross-shaped splicing seam;

(2) When the air duct is flanged, if the flange material specifications and bolt specifications are higher than the specifications, it will cause material waste to a certain extent; if it is lower than the specifications, the tightness and strength of the connection will be difficult. Guaranteed. The specifications of the materials used shall comply with the relevant regulations.

2. Selection of flanges and bolts:

(1) The distance between the bolts and rivet holes of the air duct flanges of the medium and low pressure systems shall not be greater than 150 mm; the air ducts of the high pressure system shall not be greater than 100 mm.

(2) The four corners of the rectangular air duct flange should be provided with screw holes.

(3) When the strength of the flange part of the air duct is improved by the reinforcement method, the corresponding use conditions of the flange material specification can be appropriately relaxed.

(4) The flange height of sheet steel for air ducts that cannot be flanged should be implemented in accordance with the regulations for metal flanged air ducts.