KC-2852 -- Sizing a Rectangular Supply Duct with Transversal Slots by Using Optimum Cost and Balanced Total Pressure Principle

Theoretical analysis of the pressure characteristics of the airflow in a rectangular supply duct with transversal slots has been described. The total and static pressures at various cross-sectional planes for such a rectangular duct in a textile mill were measured. Based on the results of the field survey, local loss coefficients for discharge airstream, Cc,b, and for straight-through main airstream/Cc,s, are plotted against volume flow ratio respectively. Their relationships are discussed. A proposed duct design procedure for rectangular duct with transversal slots using the balanced total pressure principle is introduced. The duct width and the total and static pressures of a sample supply duct with the volume flow rate and layout similar to the one that was surveyed are calculated and discussed.