Saw Thickness Impact on Cotton Gin Energy Consumption

Abstract

HighlightsCotton gin saws 0.91 and 1.14 mm thick were compared.Thicker saws had approximately 10% lower processing rate at full motor load.Thicker saws used about 35% more energy to gin the same amount of lint.Abstract. Most cotton fiber (lint) is separated from the seed by gin saw teeth that pull the lint between metal bars (ribs). These ribs are spaced close enough to each other that the seeds cannot pass with the lint. Cotton gin saws are available in three thicknesses, 0.9144, 0.9398, and 1.143 mm (0.036, 0.037, and 0.045 in.). No data from controlled experiments has been published which compares the effect of saw thickness on the economically important performance measures gin processing rate and energy consumption. Two shafts were prepared by installing, at the proper spacing, 406 mm (16 in.) diameter saws of 0.9144 and 1.143 mm thickness for testing on a reduced-width (46-saw) Continental Double Eagle gin stand with constant rib spacing at the USDA-ARS Southwestern Cotton Ginning Research Laboratory in Las Cruces, New Mexico. Energy consumption was recorded for target processing rates 4.88 and 6.08 g saw-1 s-1 using pre-cleaned seed cotton grown in New Mexico, Texas, and Mississippi in a randomized complete block experiment with five replicates. On this equipment we found that the thicker saws averaged 90% (4.69 g saw-1 s-1) the processing rate of the thinner saws (5.21 g saw-1 s-1). Net ginning energy of the 1.143 mm gin saws was 26.5 W-h kg-1 compared to 19.7 W-h kg-1 for the 0.914 mm saws, or about 35% more energy. Results were consistent for cottons from all three regions. Thicker saws are less likely to break under harsh conditions at the ends of the gin stand and are still recommend for use there, but there appears to be no advantage with regard to processing rate or energy use to installing thicker saws across the full width of the gin stand if rib spacing remains unchanged. Keywords: Cotton gin, Energy use, Gin saw thickness, Processing rate.