This study experimentally evaluated the filter lifespan extension achieved by a retractable, built-in air purification system equipped with a self-cleaning rotating filter. Conventional fixed-type air purifiers commonly experience a rapid increase in pressure drop and non-uniform airflow distribution as dust accumulates on the filter surface, leading to degradation in long-term purification performance. To overcome these limitations, the proposed system incorporates a retractable filter module and a rotational dust-removal mechanism designed to maintain stable airflow and reduce particulate loading during extended operation. Experiments were carried out in a controlled 30 m3 residential-scale test chamber to compare filtration performance, pressure-drop characteristics, and particle removal efficiency between the self-cleaning retractable system and a conventional fixed-depth configuration. The results indicate that the rotating self-cleaning mode reduced pressure drop by up to 18.5% and improved PM2.5 removal efficiency by approximately 12.7% relative to fixed operation. Increasing the filter protrusion depth further enhanced airflow uniformity and expanded the clean-air coverage area, thereby delaying the onset of filter saturation. Overall, the findings demonstrate that the proposed retractable, built-in air purification system effectively suppresses pressure-drop rise, maintains purification efficiency, and extends usable filter life. These results confirm the system’s practical applicability for residential indoor-air-quality management and lay the foundation for future optimization and commercialization.

The textile tentering process generates exhaust gases characterized by elevated temperature and humidity, accompanied by complex odors, fine particulate matter, and visible white smoke, all of which frequently contribute to public grievances and environmental concerns. This study evaluated a field-installed, multi-stage emissioncontrol system consisting of a scrubber, a wet electrostatic precipitator (WEFC), and a heat exchanger, with emphasis on the effect of routine plate cleaning over a ht ree-month operation. Real-time monitoring at 5-minute intervals measured temperature, humidity, total volatile organic compounds (TVOCs), particulate matter (PM2.5, PM10, TSP), and odor intensity. Odor activity values (OAVs) and odor contributions (OC) were determined from samples collected according to the Korean Odor Measurement Standard. The emission-control system reduced exhaust temperature from 150oC to below 50oC while maintaining stack outlet temperature differences within 5oC, thereby suppressing visible white smoke. The multistage system achieved mean removal efficiencies of 88.6±5.0% for TVOCs and 96.2±6.5% for PM10, with a gravimetric PM10 removal of 99.4%. Weekly cleaning of the electrostatic plates constrained day-to-day variability in odor and PM levels within ±10%, significantly lowering the frequency of white-smoke episodes. Isovaleraldehyde and acetaldehyde accounted for >90% of total OAVs, indicating the need for supplementary treatment targeting aldehydes. These results provide quantitative evidence to guide maintenance scheduling and emission-control policy for the textile processing industry.

2020년 1월 1일부터 전세계 배출통제구역을 제외한 전 해역에서 선박에 사용하는 연료유의 황함유량 기준이 현행 3.5% m/m에서 0.5% m/m이하로 강화됨에 따라 최근 대체기술로 주목을 끌고 있는 것이 배기가스세정장치이다. 배기가스세정장치는 선박의 연소기관을 통과한 배기가스를 주로 수처리를 통해 탈황 처리함으로써 황함유량 0.5% m/m 또는 0.1% m/m 등의 기준치 이하의 배기가스를 대기로 배출하는 기술을 지칭하는데 상대적으로 저렴한 전통적 인 연료유를 지속적으로 사용할 수 있다는 장점 측면에서 적용사례가 증가하고 있다. 그러나 개방형 배기가스세정장치의 경우 배기가스를 처리한 세정수가 곧바로 해양으로 배출되기 때문에 배기가스세정장치 승인에 관한 지침서에 언급된 기준 외 추가적인 중금속 등으로 인한 해양생태계에 대한 영향이 정확하게 파악되지 않았다는 점에서 중국, 싱가폴 등 일부 국가에서는 세정수의 배출금지 를 추진하고 있다. 이는 사전배려의 원칙을 실현하는 조치의 일환으로 충분히 인정할만한 조치라고 판단된다. 국제해사기구가 개발한 지침서에 따라 각국이 승인한 개방형 배기가스세정 장치에 대해 만약 향후 세정수의 유해성이 과학적으로 파악되고 모든 해역에서의 배출금지조치를 고려할 때는 선의의 목적으로 선박에 설치된 개방형 배기가스세정장치에 대해 설치당시 승인기준으로 작용한 지침서에 따라 정상적으로 작동한다는 조건하에 사용할 수 있도록 Grandfathering 조항을 명문화하여야 한다. 그리고 세정수의 유해성을 평가하기 위한 환경영향평가를 조속히 시행하여 필요하다면 배기가스세정장치의 지침서를 개정하여 새롭게 설치되는 배기 가스세정장치에 대해서는 보다 엄격한 기준을 적용하는 것이 타당할 것이다.

In this study, various physical cleaning methods such as physical washing and osmotic backwash, were conducted to understand membrane fouling properties by employing real secondary wastewater effluent (SWWE). In addition, microfiltration (MF) and ultrafiltration (UF) pretreatments were compared to maximize removal of organic matter and to control membrane fouling efficiently. Organic foulants deposited on the active layer of FO membrane were observed by fouling behavior test. The relationship between concentrations of natural organic matter and membrane fouling was also investigated from the bench-scale FO tests.

The efficiencies of thermal power system using fossil fuel depend on heat exchangers which extract energy from the exhaust gas before it is expelled to the atmosphere. To increase heat transfer efficiency it is very important to maintain the surface of heat exchanger as clean condition. The accepted skill of cleaning of fouled surface of heat exchanger is soot blowing. A high pressure jet of air is forced through the flat surface of plate to remove the deposit of fouling. There is, however, little knowledge of the fundamental principles of how the jet behave on the surface and how the jet actually removes the deposit. Therefore, the study focuses on the measuring of cleaning area and cleaning dwell time after accumulating the simulated deposit on the flat surface. The deposit test rig was built for the study and simulated deposit material is used after measuring the physical property of the each material by shearing stress test. Much data was obtained for the analysis by the parameters change such as the different jet speed, different inner pressure and variable distance of the jet from the test rig surface. The experimental data was compared with the theoretical equation and most of the data matches well except some extreme cases.

The purpose of this study is to develop a scrubber wastewater cleaning system to improve the efficiency of odor reduction. We evaluated the changes in scrubber wastewater quality and odor reduction efficiencies before and after applying the pilot system. We determined that it was possible to extend the replacement cycle by two times or more considering the turbidity change and organic removal efficiency. Butyraldehyde, a major odor-causing substances in the exhaust gas of the target facility, is soluble in water. As a result, the odor reduction efficiency was improved by removing the butyraldehyde in the scrubber wastewater. Economically, it is possible to save about 12 million won per year. Thus, it is necessary to keep scrubber wastewater clean in order to improve the deodorization efficiency and reduce the cost of disposal.

지하수를 식수원으로 활용하고 있는 대부분의 소규모 마을상수도 시설에서 방사성물질 발현에 대한 문제가 지속적으로 재기됨에 따라, 2015년 수질감시기준에 우라늄 항목이 추가되었다. 효과적인 우라늄 처리를 위하여, 마을상수도 시설에 NF 및 RO를 이용한 처리공정의 적용이 증가하고 있으나, 적용된 분리막의 효율적인 관리방법이 미흡한 현실이다. 전문적인 운영관리인원이 부족한 현실에서 안정적인 RO공정의 운영을 위한 방안으로 분리막의 세척방안 마련이 필요하다. 이를 위하여 본 연구에서는 RO공정을 마을상수도에 도입시키고 운영하며, 발생되는 RO 분리막 오염의 효과적인 제어방법을 도출코자 하였다. 효율적인 세척방법으로 산/염기의 순차적 세척방법이 도출되었으며, 약 93%의 분리막 세척효과를 확인하였다.

The development of a high pressure cleaning system is needed to properly clean cargo hold and improve the working environment of a ship. For this, the study on the parameters related to the suitable capacity of a pressure pump should be preceded.

The flushing is important to maintain good water quality in water main. It is a technique of using water velocity to remove sediments in water distribution system. The variety of water quality problems can occur in a distribution system, so too can a variety of benefits be gained by system flushing. In order to effectively perform the flushing, the contaminants to be removed to set up and it can be solved, it is necessary to ensure the proper flow rate. In this study, the removal of contaminants present in the inner water pipe attached loose deposits such as fine particles of granular activated carbon, sand and iron corrosion product sought to derive flow rates. Thus, the constant observation of using pilot plant scale water distribution plant for the movement of floating characteristics of particles were assessed.

As the fabrication technology used in FPDs(flat-panel displays) advances, the size of these panels is increasing and the pattern size is decreasing to the um range. Accordingly, a cleaning process during the FPD fabrication process is becoming more important to prevent yield reductions. The purpose of this study is to develop a FPD cleaning system and a cleaning process using a two-phase flow. The FPD cleaning system consists of two parts, one being a cleaning part which includes a two-phase flow nozzle, and the other being a drying part which includes an air-knife and a halogen lamp. To evaluate the particle removal efficiency by means of two-phase flow cleaning, silica particles 1.5μm in size were contaminated onto a six-inch silicon wafer and a four-inch glass wafer. We conducted cleaning processes under various conditions, i.e., DI water and nitrogen gas at different pressures, using a two-phase-flow nozzle with a gap distance between the nozzle and the substrate. The drying efficiency was also tested using the air-knife with a change in the gap distance between the air-knife and the substrate to remove the DI water which remained on the substrate after the two-phase-flow cleaning process. We obtained high efficiency in terms of particle removal as well as good drying efficiency through the optimized conditions of the two-phase-flow cleaning and air-knife processes.

본 연구는 정밀여과용 관형 분리막 모듈 내에 자체 설계한 기체분사형 노즐을 장착하여 막오염 감소 효과에 따른 투과유속을 측정하였다. 원료 용액으로는 0.1 wt% yeast 입자를 사용하였으며 공기 주입에 따른 막오염 감소 효과를 확인하기 위하여 공기를 주입하지 않은 경우와 주입한 경우의 투과유속을 비교⋅분석하였다. 공기를 주입하지 않았을 경우 투과유속은 지속적으로 감소하였지만 공기를 주입할 경우 투과유속은 공기를 주입하지 않은 경우와 비교하여 30% 이상 향상됨을 확인 하였다.