• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.1-13
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• 1995

In order to investigate the effect of liquid balancer in washing machine, we identify the vibration characteristics of suspension system of washing machine and formulate the 4 D. O. F. system dynamic equations. As the washing machine rotates higher speed, it is emphasized to reduce the ecentric force due to unbalanced mass. Nowadays, the most effective cancelling method of eccentric force is known as the usage of liquid balancer. To determine the liquid distribution in liquid balancer, the fluid statics is considered. The system dynamic equations are solved by Runge-Kutta method and represent the good characteristics of real washing machine in X-Y plane. The accuracy of the numerical solution was examined by experiments. The simulation results show that the unbalanced mass has so much influence on vibration magnitude and the rotating shape of spin-basket. But the effect of mass reduction due to the dehydration of the spin-basket has little influence on transient vibration.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.117-122
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• 2014

A novel method to reduce the vibration of drum type washing machine is proposed. Recently, as the capacity of the drum-type washing machine gets expanded and its washing performance is improved, its market share is increasing in the whole world. But, the capacity of washing machine is limited because of door size and built-in washing machine size. The vibration of washing machine is caused by unbalanced cloths in high spining drum, and the displacement of tub is maximized at transient range about 3 Hz(180 rpm). Previous researches were concerned about steady-state vibration in spinning. In this study, concerned about transient vibration and the displacement of tub is decreased by using gyroscope system. Mutibody dynamic model of washing machine include gyroscope is designed and the vibration of tub have been reduced by 44.7 % over original.

• Journal of Biosystems Engineering
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• v.32 no.6
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• pp.408-415
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• 2007

Leaf vegetables are composed of about 80% of moisture and 20 to 30% are damaged during the transportation due to decomposition and browning. This study was conducted to develop a washing, sterilization dehydrating system that could remove these polluters, and major findings were summarized as followings. The system was constructed so that leaf vegetables were moved through the washing, sterilization, and dehydration stages contained in a box, the shifting was conducted using PLC-controlled pneumatic pressure. Basic tests for determination of design parameters led to the results that optimum washing times by air bubbles were 5 minutes for lettuce and perilla and 10 minutes for Chinese cabbage, and percentages of bacteria removed using the optimum washing times were 94, 98, and 76%, respectively. Optimum speed and time of a centrifugal dehydrator for removal surface waterdrop on the leaves were 400 rpm and 30 s, respectively, dehydration rates were in a range $70{\sim}82%$ and damage rates were within 15% for the three vegetables tested. Operating efficiencies of the developed system for lettuce, perilla, and Chinese cabbage were 100, 120, and 80 kg/h, respectively, which were 25, 24, and 27 times of operating efficiencies of the conventional manual method.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.2
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• pp.127-137
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• 2012

This study focuses on the optimal washing conditions for dry cleaning recommended fabrics to minimize dimensional changes using wet cleaning. We suggest water-based alternatives to a perchloroethylene based cleaning process. Wool and rayon fabrics were laundered under various washing conditions and then air-dried for 24hrs. All specimens were extended after spinning and shrunk after drying. This is probably because the fibers were swollen and extended by wetting. The wool fabrics were shown to be acutely influenced by washing temperature and mechanical force. The optimal washing conditions for wool fabric to minimize the dimensional change implied a normal washing temperature and minimized mechanical force. For rayon specimens, dimensional change by a hand wash showed a remarkable decrease compared with a machine wash. Rayon fabric seemed to be influenced by the quantity of water contained in the fabric after spinning and washing time. Therefore, the desirable washing conditions for rayon fabric are to reduce the time required for washing and to increase the spin speed.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.61-67
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• 2009

A non-discharged system of sequentially physico-chemical water treatment was used to treat the contaminated water produced from washing system of soils according to full-scale soil washing. After washing the TPH contaminated soils, the remaining concentrations of COD$_{Mn}$, SS, and n-hexane were analyzed for each compartment to estimate the treatment efficiencies of non-discharged system. Three times of sampling events were conducted for 4 different compartments (sediment tank, flocculation tank, oil/water separator, and process-water tank). In addition, soil washing efficiencies and concentrations of each parameter (COD$_{Mn}$, SS, and n-hexane) for process-water tank were analyzed for about 8 months. As results, the average efficiency of soil washing was high to have 95.9%, regardless of the condition of TPH contamination level for soils, as well as the concentrations of COD$_{Mn}$, SS, and n-hexane in the process-water tank were below the regulation limits of the Water Environmental Conserveation Act. Accordingly, the full-scale washing treatment system in this study could make the washing water 100% recycled which lead the system to be environmentally-friendly and economical.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.234-242
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• 2009

This study was attempted to develop surface washing-system of ginseng. The effect of sterilization, washing and keeping freshness of ginseng through analyzing unit process were examined to establish optimal condition for washing system. Surface washing method of fresh ginseng used two way and full cone spray type. Sterilization was used at $2^{\circ}C$ water with electrolysis water of 50 and 80 ppm. Ginseng was sterilized with electrolysis water during 30 and 60 s, dehydrated during 1 min and dried during 1min at 30 and $50^{\circ}C$. Hardness of surface-washed ginseng showed good result on 1 min spraying time with 80 ppm electrolysis water at $10^{\circ}C$ storage. Ginseng with 80 ppm electrolysis water was sterilized better with $1.05{\times}103$. There are no changes with 0% on appearance quality at 80 ppm electrolysis.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.63-69
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• 2013

Most washing machines are now produced as a drum-type, where a washing drum mounted on a suspension system with springs and dampers, to minimize the transmittance of the vibration from the drum to the frame. A low-cost MR damper, using magneto-rheological fluids, can produce variable damping forces by changing the current values in the magnetic coil. Experimental results show the comparison of the vibration attenuation performances between two different dampers. One test set-up uses a passive damper and another one uses a MR fluid damper. The test results showed that the vibration amplitude of the washing machine with the MR damper is much smaller than the case with the passive damper.

• Journal of Korean Society on Water Environment
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• v.23 no.3
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• pp.391-396
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• 2007

Dry washing by air and sand to clean dishes was investigated for establishing a dry washing process in a kitchen. Thirty seasonings and foods as dirt markers and fourteen kinds of dishes were used for the experiment, and washing efficiency was evaluated by COD-MN (mg/L). It was found that air dry washing effectively reduced COD-MN of some dirt markers but not effective at all to some dirt markers. It could be also said that dirt markers would not be completely removed by air dry washing. The shape of dishes also affected COD-MN reduction by air dry washing. Sand dry washing showed excellent efficiency on COD-MN reduction. Combination of air and sand dry washing may be necessary to make a dish dry washing system which is completely independent from water.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.3-9
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• 2009

When washing machine is rotated in the laundry, it tends to lean toward one side. This tendency causes a serious vibration. The balance of washing machine plays an important role in order to reduce the vibration by injecting the sand or the salt water into the balance of washing machine. The hot plate welder is used to prevent from outflow of contents. The hot plate welder brings about many problems which is concerned with accidents. The direction recognition and location information of the balance are required in this system. In this paper, the recognition direction of balance in washing machine using machine vision system is studied. The template matching algorithm compares sub-image with original image acquired in real-time to obtain a center point of balance image. The mid points and the edges of balance are estimated by the edge detection and gauging algorithms. The data acquired by these results is used for recognition direction of balance. The automation software for image processing is developed by using LabVIEW.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.154-162
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• 2006

By laying its drum horizontally, front-loaded washing machine mostly used in Europe that uses the head of the water to launder was appropriate for washing only small amount of laundry. However, the demands of customers are requiring front-loaded washing machine to handle big capacity laundry as well, and have faster rotation speed to increase drying ability. To meet such demands, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Shaft is connected from the flange to insert production, transferring power from the motor to drum, and mainly acting as stiffness against the horizontal weight of the shafting system. In this paper, strength analysis and experiment were executed on both the shaft and flange of front-loaded washing machine to suggest the design improvement of shafting system for big capacity, high-rotation drying. Also, verification of this evaluation was executed on fracture strength and fatigue life for studied shaft system.