• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1009-1015
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• 2006

The elcetrodewatering filter press(EDFP) which had anode and cathod plates to be set between filter plates was built for reducing the waterworks sludge and improving performance of dewatering equipment. Several tests to compare the dewaterability with conventional mechanical filter press dewatering(MDEP) and EDFP was conducted through this equipment. As test results, filtration amount discharged from EDFP measured 43.2 kg which increased against MDFP, and cake weight measured 4 kg which was two times against MDFP. The water content of dewatered cake from EDFP was 55wt% and dewatering velocity was 2.3 $kg/m^2{\cdot}cycle$. This water content decrease 20% and dewatering velocity increased 30% with compare to the MDFP. That is to say, EDFP constructed from electrodewatering mechanism increase filtrate discharging amount, which make dewatering velocity increase and produce the low water content dewatered cake against MDFP. Energy consumption of EDFP is analysed to 400 kwh/DS ton. The results to analysis the economical aspect considering the power consumption and the handling cost decline as sludge volume reduction due to producing the low water content cake showed that expenses to handle sludge of 1 ton by dry solid base cut down on 20,000 won. If considering several test aspects, it was analysed that EDFP was excellent in the side of performance as well as economical suitability.

• Resources Recycling
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• v.15 no.4 s.72
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• pp.36-43
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• 2006

There was some difficulty dewatering properties due to small porosity diameter of cake, when pigment sludge contained fine particle was formed by cake under the dewatering. It was difficult to dewater the sludge with fine particles with the conventional mechanical dewatering method. This study was to improve the dewatering rate as discharging the water from porosity of cake easily, supplying the low heat to the cake layer. Thermal dewatering equipment of piston type to keep up constant temperature on the cake was set up and relative experiment was conducted for sludge of 200 g with fine pigment particle. As test results. filtration of 176.8 g, cake weight of 19.4 g, cake thickness of 4.2 mm was measured, and it was analyzed that the water content of cake was 47 wt% and dewatering velocity, which moaned the residual d교 sloid amount per dewatering area, was $2.1DS\;m^{2}{\cdot}cycle$. This results showed that filtration increased, cake weight and thickness decreased and dewatering velocity increased against mechanical dewatering method. And water content of cake decreased about 30%, so the result which dewatering rate improved was drew generally. The reason is that the inner vapor pressure working at the cake porosity increased as applying the low heat to the cake layer, which lead to discharge the water from porosity easily. Therefore, this study was estimated by the useful technology for sludge reduction.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1016-1023
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• 2006

The water content of dewatered cake produced from belt press dewatering equipment was about 75 wt% which was some high to handle it, so the equipment contained a limit at the economical and environmental aspect. The thermal dewatering equipment built as an alternative to overcome several problems was set up at the sludge treatment field and estimated some feasibility as comparison with the dewatering performance of belt press. First, dewatering properties of waterworks sludge was analyzed by monthly. The sludge of a water shortage season contained a high organic content which led to be difficult to dewater the cake, the other side the sludge of rainwater season was ease to dewater because of low organic content. According to the results to analysis the water content of dewatered cake produced from two equipments on the base of the seasonal dewatering properties, the water content of dewatered cake produced from thermal dewatering for sludge of water shortage season was $41.6{\sim}48.3$ wt% and $71{\sim}84$ wt% from belt press. In the case of rainwater season, the water content of dewatered cake produced from thermal dewatering was $34{\sim}37.7$ wt% and $57{\sim}70$ wt% from belt press. It was understood that thereduction of water content of cake by thermal dewatering was larger than belt press. The economical aspect for two equipments was evaluated on considering the reduction of cake treatment amount as the decrease of water content of cake. When putting the cost index of thermal dewatering into 100, belt press was 121. This meant that thermal dewater was more economical than belt press by about 20% in the side of construction and operation. In conclusion, thermal dewatering equipment was estimated by producing the low water content dewatered cake as well as being operated with low coat.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.108-112
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• 1996

• The KSFM Journal of Fluid Machinery
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• v.7 no.4 s.25
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• pp.53-63
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• 2004

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.324-329
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• 1996

In order to develop a novel dewatering process for soybean milk residue, hydraulic press with ohmic heating was built and its expression conditions were examined. The electric conductivity of raw soybean milk residue was 0.128 S/m and increased linearly with increasing temperature. Water content of the residue could be reduced to 74% with the conventional hydraulic press, but to less than 70% by applying ohmic heating to the hydraulic press. The most effective dewatering was achieved by applying alternative current with 5 kHz frequency at 60 V during expression. The solid content of the expressed liauid was markedly reduced from 10% to 3.3% by ohmic heating during expression. Temperature of the cake rose to above $95^{\circ}C$ during the dewatering due to ohmic heating.

• The KSFM Journal of Fluid Machinery
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• v.7 no.2 s.23
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• pp.35-40
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• 2004

A generation rate of sludge in Korea had increased dramatically about $200\%$ for a decade. A requirement for high efficiency dewatering system being possible to produce the low water content cake have suggested due to the appearance of commercial and social problems about handling of dewatered cake. The conventional dewatering system with mechanical compression device was not suitable to produce the low water content cake and didn't cope with lots of requirements. Therefore, this paper was to develop the high efficient filter press with the compressive and heating forces through the heating plate to be built between membrane fillet plates. It is possible to produce the low water content cake and improve the dewatering rate, so this equipment positively coped with several types of problems related to the sludge dewatering. The plate heated by heat transfer materials such as steam, hot water and thermo-oil made the sludge make the residual moisture within the cake to discharge easily and to improve the dewatering efficiency of equipment. The pilot scale experiment with 500kg of cake production showed that the dewatering efficiency determined by the final water content and dewatering velocity was improved $30\%$ more than the conventional dewatering equipment.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.278-283
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• 2003

A generation rate of sludge in Korea had increased dramatically about 200 % for a decade. A requirement for high efficiency dewatering system being possible to produce the low water content cake have suggested due to the appearanceof commercial and social problems about handling of dewatered cake. The conventional dewatering system with mechanical compression device was not suitable to produce the low water content cake and didn'tcope with lots of requirements. Therefore, this paper was to develop the high efficient filter press with the compressive and heating forces through the heating plate to be built between membrane filter plates. It is possible to produce the low water content cake and improve the dewatering rate, so this equipment positively coped with several types of problems related to the sludge dewatering. The plate heated by heat transfer materials such as steam, hot water and thermo-oil made the sludge make the residual moisture within the cake to discharge easilyand to improve the dewatering efficiency of equipment. The pilot scale experiment with 500kg of cake production showed that the dewatering efficiency determined by the final water content and dewatering velocity was improved 30% more than the conventional dewatering equipment.

• The KSFM Journal of Fluid Machinery
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• v.11 no.6
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• pp.82-84
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• 2008

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.6
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• pp.381-387
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• 2017

Dehydrogenation from the hydrolysis of a sodium borohydride ($NaBH_4$) solution has been of interest owing to its high theoretical hydrogen storage capacity (10.8 wt.％) and potentially safe operation. An experimental study has been performed on the catalytic reaction rate and pressure drop of a $NaBH_4$ solution over both a single microchannel with a hydraulic diameter of $300{\mu}m$ and a staggered array of micro pin fins in the microchannel with hydraulic diameter of $50{\mu}m$. The catalytic reaction rates and pressure drops were obtained under Reynolds numbers from 1 to 60 and solution concentrations from 5 to 20 wt.％. Moreover, reacting flows were visualized using a high-speed camera with a macro zoom lens. As a result, both the amount of hydrogenation and pressure drop are 2.45 times and 1.5 times larger in a pin fin microchannel array than in a single microchannel, respectively.