Drying Of Moist Cookie Doughs With Innovative Slot Jet Reattachment Nozzle

The drying of moist porous media, such as pulp, paper and food products, is one of the most energy intensive processes in industry. Many convective drying processes utilize impinging jet nozzles. There have been many efforts to improve the transport characteristics of impinging jet nozzles. Utilizing the innovative slot jet reattachment (SJR) nozzle is an approach to make the convective drying process more efficient. This is mainly because SJR nozzles overcome the high flow rate constraint associated with the traditional slot jet (SJ) nozzle. In this paper, the drying characteristics of the SJR nozzle with exit angles of +20 & x2da; and +45 & x2da; are experimentally investigated for a snack cookie. The results are compared with those of SJ nozzle based on three criteria: identical air mass flow rate, fluid flow power, and peak exerted surface pressure. An IR camera is used to capture the sample surface temperature distribution during the drying process. The results indicate that up to 57% reduction in drying time to reach 2% dry basis moisture content level is achieved with SJR + 20 degrees nozzle compared to that of SJ nozzle based on the equal surface peak pressure criterion.