Particle card room

Morey, Sasser, Bethea, and Kopetzky ( ) examined and classified the plant parts in Shirley analyzer waste from six raw cottons that had been processed through the model card room at North Carolina State University. Bract, leaf, weeds, veins and endocarp were the major plant parts present. Bract and leaf constituted up to 52 percent of the foreign matter in the cottons they examined. There was evidence that using gin lint cleaners reduced the total trash content but Increased the proportion of bract relative to other foreign-matter particles remaining in the fiber. 

The prototype cotton-dust analyzer used in the initial study was designed to measure dust smaller than 100 pm, whereas a vertical elutriator in a card room measures only the dust that is smaller than about 15 pm. Differences in particle size distributions of dust from various types of cotton would likely affect the relationship between the two dust measurements. Therefore, we deemed it necessary to investigate the use of sizing screens with smaller openings i.e., openings whose size approximated the maximum size of particles collected by a vertical elutriator. The purpose of this report is to describe additional modifications to the cotton-dust analyzer and to present data on the performance of the machine when 17-, 50-, and 100-pm sizing screens were used. 

The basic instrumentation in the present work is a Royco Model 225/518 High Concentration Particle Counter. The location of the air inlet and light sensing unit of the instrument in the card room has been described previously (2). The inlet was fitted with a vertical elutriator preseparator designed to prevent particles >15 vin aerodynamic diameter from entering the light sensor. Thus the collection efficiency of this instrumentation as a function of particle size should be similar to that of the Vertical Elutriator Cotton Dust Sampler. 

The parameters of the PSD of the particles removed from the card room atmosphere by applying 0.6% of Milube N-32 (Figure 8) were... 

Figure 9. Reduction in number of dust particles in card room as a function of diameter. Fraction removed compared with control when processing cotton with 0.60% Milube N-32 applied fn), 0.48% Texspray applied fAl, and electrostatic precipitator in filter system (O).

Particle Size Distribution and Source of Dust Components Found in Model Card Room and Library... 

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