• 한국유체기계학회 논문집
• /
• 제7권2호
• /
• pp.35-40
• /
• 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
• /
• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
• /
• pp.278-283
• /
• 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.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.526-531
• /
• 2000

Application of electrodewatering (EDW) to mechanical dewatering system was studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the sewage sludge. EDW enhancing the conventional filtration by an electric field is an emerging technology with the potential to improve dewatering. In this study, a piston filter press was constructed, the digested sludges were dewatered by EDW under conditions of DC electric field and constant pressure in the piston filter press. Constant electric field from $0{\sim}120\;V/cm$ and constant pressure $98.1{\sim}392.4\;kPa$ were used. The results showed that as electric field was increased the dewatering rates increased and as pressure was increased the dewatering rates decreased. Also as polymer was added the dewatering rates increased. This experiments produced final sludge cake with water content of 60 wt% using EDW, compared with 80 wt% using pressure filtration alone.

• 한국지반신소재학회논문집
• /
• 제7권1호
• /
• pp.23-29
• /
• 2008

지오텍스타일을 활용한 탈수처리공법은 지오텍스타일의 최신 적용분야로, 여과, 배수기능을 이용하여 기 직조한 지오텍스타일 포대 내에 산업슬러지, 하수정수장 슬러지, 특히 유수지의 준설오니슬러지 등을 주입 후 자중압밀과정을 통하여 고형물단계까지 탈수처리 하는 공법이다. 본 연구에서는 폴리프로필렌과 폴리에스터 두 종류의 지오튜브(지오텍스타일)의 물리적 특성을 살펴보고, 채움재 토사의 물리적 특성에 따른 탈수 효율과, 여과 및 배수기능을 원활이 수행할 수 있는 국산 고분자 토목섬유 적용성을 분석하였다. 실내시험은 지오텍스타일과 채움 토사간의 복합적 투수 특성을 규명하기 위한 실험을 수행하였다. 현장시험은 세립질(ML-OL) 토사의 채움 시 시간에 따른 유효높이 변화를 측정하여 적절한 슬러리 비율을 도출하였다. 각종 실내 및 현장시험결과, 세립질(ML-OL) 토사의 경우 물과 토사의 혼합비율은 최소한 6:4 이상이 되어야 하며, 폴리프로필렌 재질의 지오텍스타일이 필터 및 배수기능이 우수하며, 탈수처리 공법에 더 효과적인 것으로 나타났다.

• Journal of Biosystems Engineering
• /
• 제19권1호
• /
• pp.3-8
• /
• 1994

An experiment on the expression and dewatering of chinese cabbage was conducted in order to investigate its dewatering behavior. Chopped cabbage was packed into cylinder and pressed by piston upto the predetermined pressure on Instron-1000. The rates of dewatering were affected domintantly by the applied pressure, but not significantly by the packed amount of cabbage in the cylinder. The pressure effect was increased very abruptly at first, but the increase rate was very low at high pressure greater than 20 MPa, showing great deviation from linear dependence of flow rate on pressure in Darcy's Law. Therefore, water expression from cabbage was not Newtonian flow of water through cell wall. In fact, the squeezed water contained a lot of solid particles, about 3% of solid cabbage particles, showing destruction of cell wall. It appeared that compression and dewatering of vegetable wastes in the low pressure. under 20 MPa, is more desirable for later treatment of the dewater. More researches are needed in order to develop a treatment method for the solid particles in the expressed water before an expeller treatment system can be applied to vegetable wastes.

• 자원환경지질
• /
• 제57권2호
• /
• pp.263-270
• /
• 2024

광산배수 슬러지를 대상으로 응집제와 탈수튜브를 이용한 슬러지 탈수시스템(이하 KOMIR-Tube 시스템)의 탈수율 향상을 위한 영향인자를 평가하였다. 실험은 KOMIR-Tube 시스템으로 탈수 시 함수율 90 % 이상인 semi-active 시설 슬러지를 대상으로 하였다. 실내실험을 통해 응집제 및 투입량을 결정하였고, 현장실험을 통해 탈수율을 확인하였다. 실내실험 결과, 슬러지 탈수처리 시 응집제 선정은 침강성(sedimentation) 이외 여과성(filterability)을 같이 평가해야 하고, 이때 형성된 플럭의 적정 크기는 최소 0.7 mm 이상의 크기를 유지해야 탈수율을 향상할 수 있었다. KOMIR-Tube 시스템을 이용한 현장실험 결과, 슬러지 함수율은 강우 및 습도 등 환경적 기후 조건에 영향을 받는 것으로 분석되었다. 이에 슬러지 탈수처리는 강우량과 습도가 낮은 4월~5월에 수행하는 것이 적합한 것으로 판단된다. 또한, 슬러지의 주요 구성광물 결정도에 따라 탈수율 차이를 보였다. 특히 철수산화물 중 페리하이드라이트보다 침철석 구성비가 높은 경우, 탈수율이 높은 것으로 나타났다. 이는 페리하이드라이트의 결정도가 침철석 보다 낮고 결정형태가 뚜렷하지 않기 때문으로 판단된다. 침철석은 결정도가 높고 침상을 이루고 있어 응집 및 탈수율에 영향을 미치는 것으로 보인다. KOMIR-Tube 시스템을 이용한 광산배수 슬러지 탈수 시 탈수율에 영향을 미치는 인자는 응집제, 기후조건, 결정성 광물의 존재 유무 그리고 철화합물의 결정도 및 입자 형태로 나타났다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
• /
• pp.443-447
• /
• 2001

A laboratory-scale electrodewatering system for enhancing conventional filter pressure dewatering by an electric field has been developed to decrease the water content of sludge generated in the wastewater treatment. It consists of a piston-typed filter press, a power supply and data acquisition system. The offset of electrodewatering is investigated as a function of applied pressure, applied voltage, sludge type and filtration time. Also the optimal conditions for maximizing the dewatering efficiency in the eletrodewatering system are investigated. Electric field strength and mechanical pressure are in the range of from 0 to 120 V/cm and from 98.1 to 392.4 kPa. The dewatering rates increased with increasing electric strength. These experiments produced a final sludge cake with water content of 60 wt% using electrodewatering technology, compared with a 80 wt% using pressure filtration alone. The conventional filtration system using the electrodewatering shows the potential to be effective method for improving dewatering Sludge.

• Environmental Engineering Research
• /
• 제11권4호
• /
• pp.208-216
• /
• 2006

In order to create a single flocculant/dual flocculation system, polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride (TAEAC) polymers with varying molecular weights and structures were prepared for use of flocculants. The higher the cationic density of the polymer is higher, the higher was the conversion rate and the ratio of monomer. An acrylamide as nonionic monomer was less reactive than a TAEAC as cationic monomer. The branched polymer which was polymerized with a cross-linking agent, N, N-methylene bis-acrylamide had a higher stability and higher viscosity than a linear polymer but its dewatering efficiency was poor in a single flocculation system. In the case of single flocculant/dual flocculation, the branched polymer has better flocculation efficiency and the water content of the dewatered cakes was lower than the others, as the result of a re-flocculation effect. The optimum conditions for dual flocculation are a sequence in which the $1^{st}$ and $2^{nd}$ dosage are 75% and 25%/total dosage of a single flocculation system. The dewatering efficiency of a dual flocculation system is improved considerably from 10 to 25% under the experimental conditions used herein.

• Journal of Microbiology and Biotechnology
• /
• 제8권2호
• /
• pp.165-170
• /
• 1998

Lipase-catalyzed esterification of n-butyl oleate was carried out in n-hexane as a model reaction. The optimal activity of Candida rugosa lipase was shown in a water activity ($a_w$) range of 0.52 to 0.65 at $30^{\circ}C$. The water produced from the esterification was removed by a tubular type pervaporation system. The rate of ester formed from the enzymatic esterification was allowed to be the same as the rate of water removal by maintaining an optimal $a_w$ of the reaction system using an on-off dewatering control device. The reaction rate and yield with a$a_w$ control were increased two folds higher than the respective values for the uncontrolled reaction.

• 펄프종이기술
• /
• 제31권1호
• /
• pp.52-60
• /
• 1999

Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.