Comparison Characteristics Of FADS With Cloth Duct In The Both Of The Bottom Of Seal And Penetration

Fabric air dispersion system (FADS), which is a new flexible terminal ventilation, has beendeveloping in recent years. Cloth duct made of flame retardant polyester is the criticalcomponent of FADS. It can be used in both air transmission and air diffusion. FADS has manyadvantages such as air diffusion without feeling, anti-condensation, easy cleaning and low costetc, which can replaced traditional ventilation system and are applied for swimming pool,conference hall and hypermarket etc. It is necessary for the ventilation field to design areasonable FADS’s cloth duct including length, radius, and shape, air supply type.First of all, based on conservation of mass, momentum and energy conservation law, theairflow equations in the permeable cloth duct with the radius of0.11m and the length of8m werederived. According to turbulent flow and standard-model equation, the pressuredistribution and velocity distribution in the cloth duct with the both of the bottom of seal andpenetration were calculated by finite volume method. The airflow velocity near the fiber layer inthe1m from the inlet of the cloth duct are large. Then it only can be kept constantat a distance of1to7.5m from the inlet of the cloth duct with the sealed bottom. While it alwayscan be kept constant at a distance of1to8m from the inlet of the cloth duct with the penetrationbottom.Secondly, the airflow velocities on the cloth duct surface were measured. Those of the clothduct with the sealed bottom are discrete evenly between the minimum of0.12m/sec and themaximum of0.94m/sec. Those of the cloth duct with the penetration bottom are from theminimum of0.2m/sec to the maximum of0.7m/sec and most of it is concentrated between0.548m/sec to0.658m/sec.Finally, the cloth duct with the penetration bottom had been proved to have even the airflowvelocity on its surface in the in both theory and experiment. Then it was applied to the FADSused in the1000m2farm. It was also found that the diameter of the cloth duct may be small in case air diffusion without feeling, enough air supply for farm and fan system capacity.