Abstract
Object of study:
Fly, or cotton dust, is generated in each manufacturing process in spinning mills. It accumulates on the machines, on the floor and in other places, and lowers the quality of yarns. One method of removing fly is to blow it off and suck it away with air flow. This article deals with the theoretical aspect of the sucking of dust particles.
Results of study:
1. The following experimental formulas on the critical velocity V (m/s) of cotton tufts and sand grains have been obtained:
V=aln√G/s+b for cotton tufts
where:
where G=weight of a cotton tuft. (kg)
S=effective maximum area in which air flow works. (m2)
a=1.13, b=1.66 for rolling movement of linear cotton tufts
a=1.00, b=1.97 for rolling movement of spherical cotton tufts
a=1.84, b=2.26 for sliding movement of linear cotton tufts
a=1.51, b=2.65 for sliding movement of cylindrical cotton tufts
V=0.195 lnd+6.71 for sand
V=0.216 lnd+6.19 for molding sand
d: mean diameter of sand grains. (mm)
2. The following experimental formulas have been obtained for the terminal velocity Um (m/s) of cotton tufts and sand grains:
Um=8.35{G/S(1/γ-1/γ')}0.38 for cotton tufts
Um=3.80 d0.93 for sand
Um=6.49 d1.28 for molding sand
where γ=specific weight of air. (kg/m3)
γ'=specific weight of a cotton tuft. (kg/m3)
3. We have analyzed air flow between the floor and the nozzle as a two-dimensional potential flow and theoretically obtained its transform equation and the velocity distribution on the floor.
