Kevin D. Baker

Performance of a Pressure Pneumatic Grain Conveying System

POWER, pressure, and grain velocity of a pressure pneumatic grain conveying system were evaluated using dry shelled corn. Two system configurations (10 cm or 4 in diameter conveying pipe) were tested at grain flow rates of 3 to 20 t/h (100 to 800 bu/h) and at conveying air velocities of 15 to 30 m/s (3000 to 6000 fpm). Energy usage per tonne decreased as grain flow increased and increased as air velocity increased. All system pressure components increased proportionally as grain flow increased. Total system pressure was minimized with an air velocity of 20 m/s (4000 fpm). Pressure drop to initially accelerate corn was the same for both piping configurations and increased as air velocity increased. Pressure drop in the vertical pipe section decreased as air velocity increased. Median grain velocity decreased as grain flow increased. Reported values for terminal grain velocity approximated the difference between air velocity and grain velocity at locations where grain speeds were highest. At air velocities of 20 m/s (4000 fpm) or less, kernel velocity and corresponding potential for kernel impact damage were low.

Corn Quality During Barge Shipment

ABSTRACT FIFTEEN barges of shelled corn were sampled either at a midwest terminal elevator where they were loaded or at Gulf Coast export elevators where they were unloaded. Samples were analyzed for moisture, fine material, breakage susceptibility, kernel infection, fungal propagules, and seed germination. Temperatures within the barge were recorded for three barges shipped during different seasons. Substantial variations in these quality factors were found among and within barges. In most cases quality remained high during shipment. However, because of incomplete blending, and/or the mechanics of loading, levels of fine material exceeded 12% and moisture exceeded 17% in some portions of barges that graded No. 2. Storage mold infection was also significant in some samples. Temperature changes during shipment were greater than 3 °F in the upper 0.3 m of the grain mass (near the surface), the lower 0.3 m (at the bottom of the barge), and portions close to the vertical walls.

OVER-SIZED CYCLONES FOR LOW PRESSURE COTTON GIN EXHAUSTS

Three cyclone separators were tested in a laboratory setting at four trash loading rates. Cyclone collection efficiency for over-sized cyclones was slightly less than the efficiency of a standard-sized cyclone, averaging 98.42% and 98.64%, respectively. Cyclone collection efficiency increased as trash loading rate increased, with average values ranging from 97.94% at a trash-loading rate of 2 g/m3(0.88 grain/ft3) to an average of 98.96% at a trash-loading rate of 16 g/m3(7.0 grain/ft3). Cyclone static pressure drops for over-sized cyclones were much less than those for standard-sized cyclones, with the static pressure drop in an over-sized cyclone averaging 28% of the value for a standard-sized cyclone. The authors concluded that, with their lower pressure drop, over-sized cyclones are more compatible than standard-sized cyclones for replacing lint baskets on low pressure airflow systems that use axial-flow fans.

Emissions from Gas-Fired Agricultural Burners

Abstract. Because of the Federal Clean Air Act Amendments of 1990, the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) began defining Best Available Control Technology (BACT) for NOx emissions from cotton gin drying system gas-fired burners in its jurisdiction. The NOx emission levels of conventionally used, direct-fired burners were unknown, as was how direct-fired burners would compare against newer lo-NOx burners or against the proposed SJVUAPCD NOx emission standard of 60 ppm or less. Replicated laboratory studies were designed to determine the emissions and fuel efficiency of both direct-fired and lo-NOx burner designs. NOx emission levels during the test averaged from 3 ppm for one of the lo-NOx designs to 36 ppm for a direct-fired burner when tested over four firing rates. An economic analysis of the specific cost of NOx reduction achieved by substituting a lo-NOx burner for a direct-fired burner showed an annual capitalized cost of

Use of a Rotor Spray System for Moisture Addition to Cotton Lint

13,945/tonne (

A study of bale moisture addition

12,648/T) of NOx reduction. The SJVUAPCD has an upper limit of

Grain Damage and Dust Generation in a Pressure Pneumatic Conveying System

10,670/tonne (

Fiber Batt Reclaiming Method and Apparatus

9700/T) of NOx reduction to qualify for definition as BACT. Using this economic criterion, lo-NOx burners do not meet the definition of BACT for cotton gins for the SJVUAPCD, and, based upon conferring with industry and environmental specialists, would not for the rest of the United States.

Spindle Diameter Effects for Cotton Pickers

Tests were conducted using a rotor spray system to apply moisture in the form of fine water droplets to cotton lint at the lint slide just before bale packaging. Two studies were conducted, one in which bales were stored for 6 months and another in which bales were stored for 15 months. For the first study, initial cotton lint moisture content averaged 5.1% and ranged from 4.4% to 5.7%, wet basis, and for the second study the initial moisture content averaged 5.5% and ranged from 5.1% to 5.9%. For the 6-month storage test, five levels of moisture addition were studied, including average moisture levels of 6.3%, 6.5%, 7.0%, 7.7%, and 7.9% moisture (just after rewetting), in addition to bales with no additional moisture added. For the 15-month storage test, three levels of moisture addition were studied, including 8.0%, 8.4%, and 10.0% moisture (just after rewetting). In both studies, cotton quality degradation was determined after each of the respective storage periods. No significant changes were found in HVI micronaire, strength, length, or uniformity or any properties measured with the Advanced Fiber Information System. At moistures of 7.5% and greater, the color +b value decreased slightly and the decrease was statistically significant. When considering the moisture range used in this study, results are consistent with earlier studies using atomizing spray nozzles, therefore recommendations for using a rotor spray system for adding moisture to cotton fiber at the lint slide should be the same as those for using an atomizing spray nozzle system. Thus, in order to minimize color degradation during storage, cotton lint moisture should be less than 7.5% wet basis (8.0% dry basis) when the bale is formed.

EnginEEring and g inning dust Cyclone Technology - a Literatur e r eview

The study of the addition of water to cotton at ginning dates back to the early 1950s. Since that time, technologies have changed, allowing for more control and higher volumes of water to be added to cotton at the lint slide than ever before. The objective of this study was to determine an acceptable bale moisture range within which fiber quality, yarn quality, and dyed fabric quality degradation can safely be avoided after six months of bale storage. Approximately 22.7 kg (50 lbs) of cotton were sampled from each of the three bales for each of the four moisture treatments after six months in storage. In addition to the HVI fiber properties, additional testing of the fibers was performed on the Advanced Fiber Information System (AFIS), as well as a microbial assay to determine any microbial damage to the cotton during storage. The resulting 20/1 open-end spun yarns were subjected to typical yarn quality measurements (C.V., defects, strength, and elongation) and then circular-knit into panels so that yarn from each treatment was butt-knit to more easily observe color or shade change. HVI data indicated that the moisture treatment levels and storage period had an adverse impact on color Rd and +b with increasing amounts of water added at the lint slide. Although microbial data were collected, the data did not indicate any significant activity during the six months of storage. As for yarn quality, it appears that 9.1 kg (20 lbs) or more of water added to bales of cotton at the lint slide resulted in significant as well as practical reductions in yarn quality. With respect to the six-month storage period and the treatments used in this study, although there were color changes to the cotton fiber, there appeared to be no impact on the bleached and dyed fabric. Additionally, it appears that the point of diminishing return for adding moisture to cotton at the lint slide lies between 6% and 8.5%.