• Journal of Biosystems Engineering
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• 제38권3호
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• pp.215-221
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• 2013

Purpose: Opuntia Humifusa has been used in the food and beauty industry after removing spines and glochids clearly. This study compared the methods used in removing spines and analyzed the design factors for developing a spine removal device. Method: This study compared the spine removal ratios in accordance with the length of brush, water spray pressure, the number of water spray, and the size of Opuntia Humifusa in a rotating brush device and a water spray device. In addition, this study compared the reversal ratios according to the inclination angle of a conveyor, the drop height of Opuntia Humifusa, and the speed of the conveyor to analyze the reversal factors. Results: The spines were not removed clearly in the rotating brush method, and the glochids were nailed deeply. The spine removal ratio was 96.9% with the water spray pressure of 20 $kgf/cm^2$ and the conveyor speed of 10 cm/s in the water spray method. The number of water spray was correlated with the spine removal ratio, and the average spine removal ratio was 95.6% with three cycles of water spray. The reversal ratio was 97% with the inclination angle of the conveyor $20^{\circ}$, the drop height of 380 mm, and the conveyor speed of 10 cm/s. Conclusions: In order to develop a Opuntia humifusa spine removing device, this study compared the rotating brush and water spray methods. As a result, each spine removal performance of the rotating brush and water spray methods was 96.9% and 95.6%, respectively. Although the performance of the rotating brush method was slightly higher than that of the water spray method, the water spray method was suitable for removing spines from stem because the epidermis of stem was damaged and the glochids were nail deeply in the rotating brush method. Further studies on appropriate arrangement of spray nozzles, maintaining the optimal water spray pressure, the speed and angle control of the feeding conveyor, and devices for inducing the stem to the center will be needed in combining the water spray device and the reversal device.

• 월간산업보건
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• 통권8호
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• pp.4-30
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• 1988

Examination of working environments was conducted to get more detailed data about harmful working environments and to make a contribution to more effective management. Study was carried out on 722 factories located in Taegu city and eight counties in Kyungpook Province, Korea, for a period of one year, from February 1 to December 30, 1986. The total number and proportion of workers exposed to harmful material was 37,697, 45.2% among 83,368 workers. The results according to exposed material were as follows: 1. In the case of noise, proportion of exceeding the 8-hour TLV was 59%, Included were nail-cutting in assembly metal manufacturing industry and weaving process in textile. 2. Dust in mill process of coal manufacturing industries exceeded the TLV of second class of dust at all parts and exceeded the TLV at 6% as a whole.: 3. The fields of industry lower than 70 lux of illumination were storage equipment of food, auto-winder of textile, painting of wood wares and coal mixing, and 44% of all cases was lower than standard. 4. As a result of temperature index investigation(WBGT), about 12% of all sujects exceeded limit value. Included parts were rolling machine and reducing room. 5. In the case of organic solvents, TLV was exceeded at about 8%, The parts exceeded TLV according to materials belonged to this category were as follows. 1) Toluene: adhesive work in assembly metal manufacturing 2) Xylene: printing and paint mixing in chemical manufacturing 3) Methyl ethytl ketone: paint mixing in all parts examined and coating machine partially in chemical manufacturing 4) Methyl isobutyl ketone: printing in chemical manufacturing 5) Acetone: vapor polishing in assembly metal manufacturing 6. Among specified chemical materials, the concentration of HC1 in the air in metal assembly manufacturing factory exceeded TLV. in one of three assembly metal manufacturing examined. Others, such as benzene, acetic acid, formic acid, sodium hydroxide, formalin, ammonia, copper, chromate etc. were lower than TLV in its indoor atmospheric concentration. As a whole, the proportion of exceeding TLV was about 0.8% 7. The concentrations of inorganic lead were lower than TLV in all parts examined. The results of this investigation show the fact that current management of working environments is not satisfactory, and so more active management is needed.