Please use this identifier to cite or link to this item:
Title: Study of residence time distribution in a pilot-Scale screw conveyor dryer
Authors: Waje, S.S.
Patel, A.K.
Thorat, B.N.
Mujumdar, A.S. 
Keywords: Axial dispersion
Fraction of plug flow
Mean residence time
Pilot scale
Relative stagnancy
Screw effectiveness
Issue Date: Jan-2007
Citation: Waje, S.S., Patel, A.K., Thorat, B.N., Mujumdar, A.S. (2007-01). Study of residence time distribution in a pilot-Scale screw conveyor dryer. Drying Technology 25 (1) : 249-259. ScholarBank@NUS Repository.
Abstract: The screw conveyor dryer (SCD) finds varied applications in the process industries either as a pre-dryer or for post-drying operation. In certain cases, it can be used as the main dryer. The full potential of SCD has not been exploited for the lack of its understanding. The conveying of paste or particles through a screw conveyor may follow a near plug flow behavior; however, it is essential to ascertain a desired level of inter-particle mixing during the course of drying/conveying so as to obtain the desired drying conditions. The effects of feed rate (15-176 kg/h) and screw speed (10.8-28 rpm) on the RTD were studied for the conveying of sand in a pilot-scale SCD using pulse input of a tracer (dye-coated sand). Two new parameters defining the relative stagnancy and screw effectiveness were introduced to study the flow performance of SCD. The flow in the SCD approaches plug flow with an increase in feed rate or by decrease in the screw speed. A low value of the holdback, a parameter of relative stagnancy, indicates the flow in SCD to be near plug flow. Mean residence time was found to be 3 to 4 times longer than the linear residence time due to lower values of screw effectiveness (0.24-0.32).
Source Title: Drying Technology
ISSN: 07373937
DOI: 10.1080/07373930601161120
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Feb 13, 2019


checked on Feb 13, 2019

Page view(s)

checked on Jan 26, 2019

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.