When the air duct is installed vertically, the spacing shall not be greater than 4m, but the fixed parts of each riser shall not be less than 2..
The flange of rectangular air duct shall be riveted with galvanized rivets.
The appearance quality of the air duct shall meet the requirements of straight corner, uniform arc, parallel surfaces at both ends, no warping angle, and the surface concave convex shall not be greater than 5mm; The air duct shall be firmly connected with the flange, the flanging shall be flat, the width shall not be less than 6mm, and close to the flange.
If a support diaphragm is added to the air duct, the material thickness shall be the same as that of the air duct.
If the distance is more than 150mm, a intubation tee shall be made, and the connection shall be tight.
(2) The following methods are adopted for fixing the supports and hangers: ① expansion bolt method.
The junction between the branch pipe and the main pipe of the air duct is a tee branch.
2.
The turning radius of air duct is generally r = D.
The spacing of supports and hangers shall be carried out according to the design requirements.
When the distance between the branch pipe and the bottom surface (or top surface) of the main pipe is less than 150mm, an arc tee shall be made.
11.
Before riveting, the flange shall be derusted and then painted with two layers of Zhangdan.
This method is applicable to use embedded parts to weld and fix the supports and hangers when the specification of air duct is large and the strength cannot be met by using expansion bolts.
② Welding method.
In order to improve transportation efficiency, reduce consumption and the integrity of finished products, the method of workshop prefabrication and on-site assembly is adopted, that is, the workshop is mechanically processed into semi-finished products and transported to the site for assembly.
One support and hanger shall be set every 3M.
4.
The undercut width and allowance are determined according to the thickness of the plate.
This method is applicable to the fixation of air duct supports and hangers with small specifications.
For the parts where the air duct pipeline is long and the air duct is arranged neatly, when installing the supports and hangers, first install the supports and hangers at both ends, and then take the supports and hangers at both ends as the benchmark to find out the elevation of the middle support by the pull wire method for installation.
Installation of supports and hangers (1) the positions of embedded parts and expansion bolts of air duct components, supports and hangers shall be correct, and the supports and hangers fixed with expansion bolts shall comply with the provisions of technical conditions.
5.
The rectangular short radius elbow shall be equipped with guide vanes.
7.
system category plate connection mode 1 air conditioning air supply duct, fresh air duct and exhaust duct (diameter of circular air duct or large side length of rectangular air duct) ≤ 200 > 200 ~ 500 > 500 ~ 1120 δ= 0.5 galvanized sheet δ= 0.75 galvanized sheet δ= 1.2 galvanized sheet flange connection > 1120 δ= 2.0 ordinary steel plate welding 2 firewall air duct (diameter of circular air duct or large side length of rectangular air duct) ≥ 200 ~ 500 > 500 ~ 2000 δ= 1.0 galvanized sheet δ= 1.2 galvanized sheet flange connection 3 ventilation pipe welding steel pipe welding in embedded concrete 4 fire smoke exhaust air pipe δ= 1.6 ~ 2.0, ordinary steel plate welding or flange connection 3.
The bite form of air duct is selected as follows: the four corner combination of rectangular air duct or accessories adopts combined corner bite.
fabrication of ventilation, smoke control and air conditioning air duct 1.
The support shall be embedded in the upper and later stage of the brick wall.
Before construction, a detailed scheme shall be formulated according to the site conditions, and the air duct processing, air duct and equipment installation and commissioning shall be completed in turn according to the construction flow chart.
The distance from the upper surface of the support to the ground shall be calculated according to the air duct elevation.
The bite joint of air duct shall be closely combined, and the bite joint width shall be uniform.
No.
Construction flow chart: I.
The specific dimensions are shown in the following table: plate thickness, flat undercut width b, corner undercut width B0 7 below 6 ~ 86 ~ 70.7 ~ 0.828 ~ 107 ~ 80.9 ~ 1.210 ~ 129 ~ 10 air duct bite width table (mm) 10.
Connection mode of angle steel flange: material specification table of metal rectangular air duct flange length of air duct (mm) material specification of flange (angle steel) ≤ 63025 × 3630~150030 × 31500~250040 × 42500~400050 × 58.
At the same time, anti sway support shall be set at appropriate position.
The radian of the deflector shall be consistent with the angle of the elbow.
See the following table for the material and connection of air duct.
9.
The hanger shall not be directly hung on the air duct flange.
After finding the correct position and drilling the hole, the support shall be embedded in the hole, embedded in the groove with 1:2 cement sand hanger, and filled with cement mortar.
Rectangular elbow deflector (1) the long side size of air conditioning duct is greater than 500mm, and the right angle elbow shall be added with deflector.
The thickness of the guide vanes shall be twice that of the air duct, not less than 60mm, and the number of pieces shall not be less than two.
When the metal rectangular air duct is connected with the angle steel flange, when the pipe wall thickness is ≤ 1.5mm, flanging riveting can be adopted, and the riveting shall be firm; When the pipe wall thickness is more than 1.5mm, full welding or flanging intermittent welding can be adopted.
The bite of rectangular air duct shall be tight, flat and free of burrs.
The fixing form of the support is shown in the figure below.
During operation, the force shall be uniform, not too heavy, and there shall be no half bite or expansion crack.
(2) The windward side edge of the deflector shall be smooth, its two ends shall be firmly fixed with the pipe wall, and the arc length of the deflector in the same bend shall be the same.
The air duct elbow shall be made according to the standard drawing 91sb6.
6.
When the side length of metal rectangular air duct is more than 630mm and the side length of thermal insulation air duct is more than 800mm, and the length of pipe section is more than 1250mm, or the single side flat area of low-pressure air duct is more than 1.2m2, and the medium and high-pressure air duct is more than 1.0m2, reinforcement measures shall be taken.
(4) Supports and hangers shall not be installed at air outlets, valves, inspection holes, etc., so as not to affect the operation.
(3) Before the installation of supports and hangers, find out the laying position of suspenders according to the center line of air duct, and the single suspender is on the center line of air duct; The double suspenders shall be installed symmetrically according to the screw hole spacing of the bracket or the center line of the air duct.
The connection mode of ventilation duct is angle steel flange connection, which is suitable for high-pressure ventilation system (smoke control system and super static pressure system).
II.
Most supports and hangers in the project are fixed by this method, and the supports and hangers are fixed by punching expansion bolts on the floor slab and beam column.
The flexible joint of air duct of air conditioning and ventilation system can be made of canvas, and the smoke exhaust system can be made of incombustible soft materials.
Installation process flow of air duct components, supports and hangers: 1.
