1. Dongguan spiral air duct has good air flow, large effective flow area, small system pressure drop, and low power consumption for daily operation. At the same time, because the spiral duct uses a spiral bite, its strength is higher than that of an iron duct with the same specifications. When the air is transmitted through the pipe, the spiral-shaped seam is provided on the circumference to increase the strength of the duct and it is not easy to generate vibration. Therefore, it has a good sound insulation effect in reducing the transmission of low-frequency noise and can effectively reduce the pipe. The walls pass sounds to improve the quality of the building. Studies have shown that the counterslotted pipe and spiral pipe made of D200 with a thickness of 26 # steel plate, because the rigidity of the spiral pipe is higher than that of the counterslotted pipe, its low frequency band is 3-10dB lower than the latter, and the mid-high frequency band is 12 ~ 20 dB. Under the premise of similar duct section and duct material thickness, the sound insulation of elliptical spiral duct in low frequency band is better than that of rectangular duct by about 10dB.
2 Dongguan spiral air duct is highly mechanized. Spiral elliptical air duct. The spiral air duct uses strip steel coils. It is blown out by the duct forming machine at one time, and is rolled into a circular tube along the spiral involute trajectory. At the same time, the bite seam is compacted, and finally the circular duct is shaped into a flat ellipse by using special equipment. Users can cut according to the required length. The manufacturing of spiral duct is highly automated, and the production speed is very fast. At the same time, factory production and standardized production are adopted, which makes the production efficiency of oval spiral duct greatly improved and the integrity is strong.