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. 

Dust levels in card rooms have been shown to be reduced by use of successive lint-cleaning stages ( ). Most gins (65 percent) have two lint cleaners in series and some (19 percent) had three stages in 1978 (34). Up to three stages of lint cleaning caused continued dust reduction (35, 36) and use of dryers in conjunction with cleaners enhanced their effect (33). 

Finish Wax Reduction Ethyl Alcohol Card Room ... 

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. 

Additional tests are underway to more accurately determine relationships between data from the cotton-dust analyzer and data on card-room dust levels as measured with a vertical elutrlator. At present, the Information available as a basis for comparing the two dust-measurement techniques Is limited. The comparisons shown In Figure 4 were based on several analyses of samples from six cotton lots. Although limited In scope, the data Indicate the likelihood that the correlation between the two measurement techniques will be reasonably good. 

Figure 4. Card room dust levels vs. dust content measurements by a cotton dust analyzer (17-iim sizing screen).

Figure 2. Sample plant layout of card room subdivided into five sections representing two work...

The first experimental demonstration of the magnitude of x, was performed with the CAM System at the N.C. State University model card room in November 1979 (1,1). Subsequently, several in-plant demonstrations have been made with the CAM System, with... 

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. 

Figure 8. Cumulative distribution curves of distributions shown in Figure 7. Key , cotton control O, 0.60% Milube N-32 A, distribution of dust removed from card room atmosphere when Milube N-32 is added to cotton.

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).

Figure 10. Cumulative distribution curves of dust in card room atmosphere while processing cotton with an electrostatic precipitator (ESP) in filtration line. Key curve for ESP energized O, curve for ESP not energized and A, size distribution removed by ESP.

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

Analyses of Card Room and Other Textile Mill Dusts... 

A number of investigators have reported proximate analyses and elemental composition of textile mill dusts and trash. Only two of these involve studies of dusts collected with an elutri-ator sampler (20,31). Samples from both of these studies were collected in a model card room at North Carolina State University (42). In one of these, glass fiber filters were used and the dusts were analyzed for average ash contents (see Table IV). The total ash content was about 20%. The average ash content of area samples also collected on glass filters was found to be slightly lower. 

Recent reports suggest that a significant portion of the dust measured by a vertical elutriator in a card room may be due to solids in humidifier water (23,25,43). Undoubtedly, much of the inorganic matter found in the model card room dusts arises from this source. 

Brown and Bern (26) cinalyzed the elemental composition of four card room dusts using X-ray fluorescence spectroscopy. Two of these were from filter cake material collected in two textile mills from which fine dusts (<20 ym) were separated by mechanical agitation (sonic sifting). The third sample was from filter cake material collected in a textile mill from which dust was removed by hexane washing followed by sonification of the bath, filtration and further sonification. The fourth sample came from dust collected on an electrostatic precipitator in a model card room. Results are shown in Table VI. 

Mittal, et al. reported the proximate chemical composition of a number of different samples collected in the model card room at North Carolina State University (31). Samples in this study included a coarse trash which was comprised of relatively large, mostly lint-free particulate matter that fell to the floor of the condenser filter chamber in a Pneumafil filter system (Model FCV8-3MTRK) (31). The second sample set was separated by the sonic sifting procedure from the condenser trash. Another set of samples was collected from an electrostatic precipitator located in the air conditioning return of the model card room. Results of ash analyses are shown in Table VII. 

Analysis of materials from the Model Card Room at North Carolina State University (31)... 

Batra, Fornes eind Hersh (23) recently demonstrated that a significant amount of the material captured by vertical elutria-tors in the model card room at North Carolina State University arises from solids generated by the evaporation of humidifier water. Table IX shows variation in dust concentrations in the card room with and without the contribution of humidifier particulates (23). 

TABLE VIII Minerals Identified in Electrostatic Precipitator Dusts Collected in a Model Card Room (16) ... 

Humidifier Effects on Dust Concentrations Measured in a Model Card Room Without Feeding Cotton to the Opening-Carding System (23)... 

Fisher md coworkers (24) have investigated the solids in the card room water supply. Solids content data is given in Table XI. Water samples were taken from the card room at random intervals and 1000 ml S2unples were evaporated to dryness in a crucible on a hot plate. The weight of the dried solids was obtained. The S2unple was ignited at 550 C for 5 hr and ash... 

Solids Content of Model Card Room Humidifier Water Samples (24)... 

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