I. Core Process Types of Air Duct Processing
Air duct processing is a core link in building and industrial ventilation systems, and its process quality directly affects the operating efficiency and safety of the system. The following are the technical points of two key processing technologies:
1. Ordinary Angle Steel Welded Flange Process
This process requires precise cutting - to - size of angle steel. The flange processing adopts positive deviation control to ensure matching with the air duct. During the welding process, defects such as slag inclusions, air holes, and undercutting must be strictly avoided. The side length, diagonal length, and flatness of the flange must meet the design requirements. In addition, the bolt holes of the flange need to ensure universal compatibility to achieve efficient assembly of multi - section air ducts.
2. Insert Flange Process
While the insert flange meets the basic standards of angle steel flanges, special attention should be paid to the silicone sealing treatment of the insert parts. The silicone should evenly fill the gaps to ensure that the airtightness meets the standard and prevent air leakage or pollutant infiltration during operation.
II. Technical Specifications for Air Duct Reinforcement and Anti - Corrosion
After processing, the air ducts need to be reinforced and anti - corrosion treated to improve the structural strength and durability.
1. Reinforcement Standards and Implementation Methods
- Reinforcement Conditions: When the large side length of the rectangular air duct is ≥630mm (non - insulated) or ≥800mm (insulated air duct), and the length of a single section exceeds 1250mm, additional reinforcement measures must be added.
- Material Selection: The reinforcement material should be consistent with the flange material. Commonly, angle steel or flat steel is used for horizontal or vertical support. The reinforcement spacing should be adjusted according to the air duct pressure level. For example, when the unilateral reinforcement area of the low - pressure system air duct exceeds 1.2㎡, additional reinforcement is required.
2. Full - Process Anti - Corrosion Treatment
- Pretreatment Stage: Before assembly, the steel plate air ducts need to be painted with anti - rust paint inside and outside. Metal components such as supports and hangers should ensure the integrity of the anti - corrosion layer. Before construction, the metal surface needs to be degreased and sand - blasted for rust removal to reach the Sa2.5 - level cleaning standard.
- Environmental Control: The anti - corrosion operation should be carried out in an environment with a temperature of ≥5℃ and a humidity of ≤80% to avoid poor coating curing. The rust - proof primer should be pre - sprayed before flange pressing, and the top - coat paint should be applied after installation to form a double - layer protection.
