Process Air Handling

Heating/Drying Performance - CFD Analysis Leads to more Effective Nozzle Pattern

Equipment was being developed to heat and dry a product stream through impingement from a series of nozzles. The original design used a finely spaced rectangular array of small nozzles. As the simulation results show, however, the air jets are deflected by laterally flowing exit gas, even for relatively small distances between the nozzles and the product. For larger distances, there is no visible "signature" of the jets on the product.

The revised design replaces the larger number of small nozzles with fewer large nozzles. Note that since both designs use a square array, the simulation domain is larger in the product flow direction for the revised design than for the original design.

Although the total gas flow volume is the same for both designs, the revised design is much more effective at getting the gas to the product surface. The gas jets are unaffected by the lateral flow and there is little variation across the width of the equipment.

Note that different color scales were used for the two heat transfer rate plots. The heat transfer rates for the revised design are actually much greater than for the original design.