본 연구는 지카바이러스, 메르스, coronavirus disease-19 (COVID-19) 등의 감염병 방역 및 의료현장에서 사용할 수 있는 의료용 공기정화호흡기(powered air purifying respirators, PAPR)의 항균성 보호복의 후드와 필터를 개발하였다. PAPR은 전동팬 본체 및 필터, 배터리팩, 후드로 구성되며 보호복의 후드 소재는 뛰어난 흡습성, 풍압, 외부충격을 견딜 수 있는 폴리프로필렌 슐폰레이스(spunlace) 부직포 직물(SFS)을 사용하였다. 사용자의 감염위험을 낮추기 위해 후드의 외피에는 피톤치드계 물질을 사용하여 99.9%의 안티-박테리얼(antibacterial) 효과를 얻었으며 내피에는 친수가공을 하여 흡수성을 25% 향상시켰다. 의료용 보호복 후드에 필요한 인공혈액 침투저항성, 건조미생물 침투저항성, 습식세균 침투저항성, 그리고 박테 리오파아지 침투저항성을 평가한 결과 2~6 단계의 합격평가를 받았다. 한편, 항균 처리된 슐폰레이스(spunlace filter, SF) 헤 파 필터(high efficiency particulate air, HEPA)의 성능을 평가한 결과 우수한 항균성, 분진제거율, 차압 효과를 확인하였다.

There is a need for the purification of indoor air owing to a high rate of pollution in today’s world. For this, cabin air filters (CAFs) are widely used, which requires the addition of certain adsorbents to increase the volatile organic compound (VOC) removal efficiency. However, this addition causes high-pressure resistance, which may hamper commercial applications by requiring more energy and negatively affecting fresh air delivery rate. Hence, in this study, a high-performance combined CAF (CCAF) with excellent dust and chemical filtration performance and low differential pressure was prepared using granular activated carbon (GAC)/activated carbon fiber (ACF) mixed medium. The GAC/ACF mixed medium had higher air permeability than the ACF medium of the same weight, and it exhibited similar ultrafine dust filtration performance to the ACF medium without an increase in differential pressure. In addition, the GAC/ACF mixed medium showed excellent gas removal performance without increasing differential pressure by combining the VOC removal characteristics of the GAC and ACF filter media. The improved VOC removal performance of the GAC/ACF mixed medium was due to the hybrid effect of the hierarchical pore structures of the GAC and the nearly uniform pore structures of the ACF, which resulted in a slow and increased gas adsorption by the GAC and rapid gas adsorption of the ACF.

The background of the development is to contribute to the reduction of radioactive waste, recycling of resources and effectively purifying the air in the workplace. Ultimately, it affects the reduction of internal exposure of workers. According to the standard procedure of KHNP,「Use and Management of Respiratory Protection Equipment」, the expiration date of mask filter is indicated by the manufacturer before opening. It is 1 year from the date of first combination after opening. We have developed an air purifying equipment that can recycle and reuse expired mask filter waste in nuclear power plant. In order to confirm the performance, we observed air pollution level by operation time. The location was measured at 3 locations including the decontamination product warehouse in NPP, and the size of the measurement locations were 53 m3, 150 m3, 180 m3, and 900 m3. As a result of measurement, significant air purification effect was found in 53 m3 and 150 m3. Decontamination effect of 80% was shown after 1 hour of operation, and 20% of decontamination effect was shown gently for 3 hours thereafter. On the other hand, there was no significant decontamination effect in the 180 m3 and 900 m3 spaces. Significant results were derived by statistical methods. Statistical procedure involves the collection of data leading to test of the relationship between two statistical data sets, or a data set and synthetic data drawn from an idealized model. The basic composition and product characteristics was as follows: Blower, filter fixing unit, Air purifier outlet round shape, Differential pressure gauge, inverter (200 V, 3π, 200 W). The developed product weigh is 25 kg. This is lighter than the existing product weighing 100 kg. It is judged that it is suitable for convenient use. Because the area where the major air pollution level occurs is isolated by a room in NPP. This developed product has a greater significance in that it recycles radioactive waste within the radiation management area rather than air purification efficiency.

Recently, the importance of air filters used in air purifiers and ventilation systems is emphasized in Korea. As a result, air filter test reports are required by users to ensure the removal efficiency of particulate matter. However, the tests are conducted for the filter material alone, which lead to a possible discrepancy between the test report and actual efficiency when applied to actual devices. Therefore, in this study, the removal efficiency data of the filter test reports were compared with actual filter efficiency data after application to the ventilation systems for some ventilation systems in the market. For ventilation system A, the field test results using filter leakage test method were slightly lower than those in the test report but nearly the same. For ventilation system B, the field test result was much higher than reported in the test report. This was due to the broad range of particle sizes measured using the filter leakage test method. The field tests using the particle counter method showed that the removal efficiency of ventilation system A for 0.3 μm was under 50% which translates to less than half of those of the filter test reports. For ventilation system B, the removal efficiency was 15%~21%. much lower than reported in the filter test reports. The lower removal efficiencys are mainly assumed to be caused by leakage of the filter installation among other factors. Therefore, the field test methods for the particulate matter removal efficiency of ventilation systems should be established to verify actual efficiency and improve the efficiency in the future.

This study was carried out considering that activated carbon physically adsorbs radon. Among the air cleaners equipped with activated carbon filter, eight air cleaners sold in Korea were selected and the radon reduction rate experiment was conducted. The instrument used an ionization chamber type instrument with a sensitivity of 3 CPM. The experiment was carried out by excluding the natural rate of reduction of radon in order to accurately grasp the radon reduction rate of activated carbon filter. Of the eight air purifiers, only three showed a reduction rate of more than 30%, while the remaining five air purifiers showed a reduction rate of less than 20%. This does not seem to be much different from the natural reduction rate. In addition, since it is not adsorbed by radon alone due to the nature of activated carbon, it is expected that the reduction rate will be lower in a real life environment.

A study on air bag filter for passenger car which is manufacturing preocess and method of very important one of the components. The manufacturing equipment consists of various component which nitting cam, nitting knife, rollers. The development target is weight reduction of metal filter, reduction of process.

A high efficiency roll-type electret polypropylene (PP) filter with an external electric field was developed and its particle collection efficiency and air cleaning capacity was investigated in a room when applied to an air cleaner having a fan. To enhance air cleaning performance of the cleaner, a wire-plate type ionizer was installed in front of the filter to enhance electric field to filter and one side of the filter was embossed by press of a pattern with a lot of circular projection. Performance test results showed that the newly developed electret PP filter with an ionizer becomes an appropriate filter to be applied to indoor air cleaner due to its low pressure drop and high air cleaning performance.

In recent European telecommunication base transceiver stations(BTS), a membrane laminated air filter is reported to replace a heat exchanger in order to cool internal digital units of BTS. The concept of using the air filter is for the direct ambient cooling (DAC) of BTS without heat loss generally found in the heat exchanger type BTS. In the present study, a performance evaluation experiment was conducted to investigate the pressure drop characteristics with dust loading and the particle collection efficiency of the air filter for the DAC of BTS. Finally, the long term operation lifetime of the air filter for BTS was suggested with a given fan rotation speed.

Activated carbon fiber (ACF) filters are widely used to remove volatile organic compounds (VOCs) in air cleaning devices. The performance of ACF filters could be enhanced combining adsorption process with photodegradation process. In this study, to investigate this enhancement effect, a duct-type reactor was made and TiO2 was i㎜obilized on a co㎜ercialized ACF filter. Benzene, toluene, and m-xylene (BTX) were chosen as target compounds. Removal experiments for BTX were done under different air velocity and upstream concentration conditions. The range of inlet concentration was 200～1,400 ppb and the air velocities were 0.4, 0.7 and 1.0 m/s. Adsorption by an ACF filter alone showed high removal efficiency of BTX, depending on the BTX species, the upstream concentration, and the air velocity. The combination of TiO2 and ACF filter significantly increased removal of benzene which was less removed than other pollutants by an ACF filter alone. It was found that the combination effect was small in removal test of toluene and m-xylene. Removal efficiency in the tested experimental conditions was decreased in order of toluene > m-xylene > benzene.

The purpose of this work is to develop a new type of particle collection filter using electrical discharge technology. The new filter must be high efficiency and applicable to air conditioner to use for household, so we suggested the new type filter. The new type filter has a distinctive feature except characteristic of ESP, a thickness of collecting electrodes is thicker than that of existing type ESP. When particles come into the filter, the particles will collide with side surfaces of the collecting electrodes. At the same time of particle collision with side surface, the particles are charged by the collision and collected by electrical force. Therefore, we called this type "Ion Impactor". We optimized condition of thickness of collecting electrodes and applied voltage using six sigma method because thickness of collecting electrodes and applied voltage are very important to improve the collection efficiency. We analyzed distribution of electric field line, the electric field lines were uniformly distributed on the side surface of the collecting electrodes. From this analysis, we can see the improvement of the particle collection efficiency. We made the ion impactor type filter on a large scale to equip to the air conditioner, and measured the particle collection efficiency. For the 0.1∼0.2㎛ range particle, the collection efficiency was higher than that of existing type ESP by 30%. The collection efficiency of the 0.3∼0.4㎛ range particle was higher by 12%.

In this study, using coke dust from ironwork, the pulse pressure on a pulse air jet bag filter was investigated considering the influence of the pressure loss due to filtration velocity and pressure intervals. The research on the optimal pulse pressure prediction of a pulse air jet type bag filter using coke dust showed the following results. Pressure loss volatility produced by the pulse pressure under low dust concentration(0.5, 1 g/m3) and low face velocity(1.25 m/min) was less than 10 mmH2O. This suggests that the pulse pressure has a low impact on the pressure loss. In contrast, pressure loss volatility under high dust concentration(3 g/m3) and high face velocity(1.75 m/min) was 25 mmH2O. Therefore, pulse pressure with high dust concentration and high face velocity has a strong influence on the pressure loss volatility, compared to the condition of low dust concentration and low face velocity. The optimal pulse pressure of inlet dust concentration(0.5 g/m3) was 6 kg/cm2 under the same face velocity(1.75 m/min). As concentration increased from 1 to 2 g/m3, the pulse pressure gradually reached 5 kg/cm2 thus indicating that the pulse pressure(5 kg/cm2) is pertinent at a high concentration(3 g/m3). The pulse intervals: 20, 25 and 30 sec, which are relatively longer than 10 and 15 sec, corresponded to high pressure loss volatility produced by the pulse pressure. Furthermore, low pressure loss volatility was noted at 5 kg/cm2 of the overall pulse pressure.

This study was carried out to investigate the formaldehyde (FA) filtration pattern of additional media for indoor biofilter system. Dry pellet type activated carbon (PAC), activated clay (ACL), zeolite, diatomite, pumice and loess ceramic ball were tested. In the case of dry filter media, formaldehyde purification efficiency was the most excellent with activated clay and then was good with the activated carbon, diatomite, zeolite, and pumice order. PAC and ACL decreased the FA concentration with exponential pattern resulted from dynamic balance between emission and purification. Zeolite, diatomite, pumice, and loess ceramic ball showed high filtration rate at initial time and then increased FA concentration result from breakthrough. PAC, zeolite and diatomite could be recommended as additional filter media for biofilter system considering FA filtration and breakthrough characteristics. FA filtration and breakthrough characteristics were improved with wet media except PAC and ACL. In particular, purification performance improvement and breakthrough mitigation were higher in pumice and loess ceramic balls. PAC+ZEO mixing showed the most high purification performance and breakthrough mitigation in all mixing methods. Thus mixture of PAC with zeolite and vertical mixing could be recommended as additional filter media to improve the FA purification ability and pressure drop with indoor air biofilter system.

The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (N dust = ω0υf / P pulse t) and the dust mass number term (Δp initial), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance (K d), one of the empirical static model parameters got the minimum value at , d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at , d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

The pressure drop through pulse air jet-type bag filter is one of the most important factors on the operating cost of bagfilter houses. In this study, the pilot-scale pulse air jet-type bag filter with about 6 ㎡ filtration area was designed and tested for investigating the effects of the four operating conditions on the total pressure drop, using the coke dust collected from a steel mill factory. When the face velocity is higher than 2 m/min, it is not applicable to on-spot due to the increase of power expenses resulting from a high-pressure drop, and thus, 1.5 m/min is considered to be reasonable. The regression analysis results show that the degree of effects of independent parameters is a order of face velocity > concentration > time > pressure. The results of SPSS answer tree analysis also reveal that the operation time affects the pressure drop greatly in case of 1 m/min of face velocity, while the inlet concentration affects the pressure drop in case of face velocity more than 1.5 m/min.

Research results for the pressure drop variance depending on operation conditions such as change of inlet concentration, pulse interval, and face velocity, etc., in a pulse air jet-type bag filter show that while at 3kg/cm2 whose pulse pressure is low, it is good to make an pulse interval longer in order to form the first layer, it may not be applicable to industry because of a rapid increase in pressure. In addition, the change of inlet concentration contributes more to the increase of pressure drop than the pulse interval does. In order to reduce operation costs by minimizing filter drag of a filter bag at pulse pressure 5kg/cm2, the dust concentration should be minimized, and when the inlet dust loading is a lower concentration, the pulse interval in the operation should be less than 70 sec, but when inlet dust loading is a higher concentration, the pulse interval should be below 30 sec. In particular, in the case that inlet dust loading is a higher concentration, a high-pressure distribution is observed regardless of pulse pressure. This is because dust is accumulated continuously in the filter bag and makes it thicker as filtration time increases, and thus the pulse interval should be set to below 30 sec. If the equipment is operated at 1m/min of face velocity, while pressure drop is low, the bag filter becomes larger and thus, its economics are very low due to a large initial investment. Therefore, a face velocity of around 1.5 m/min is considered to be the optimal operation condition. At 1.5 m/min considered to be the most economical face velocity, if the pulse interval increases, since the amount of variation in filter drag is large, depending on the amount of inlet dust loading, the operation may be possible at a lower concentration when the pulse interval is 70 sec. However, for a higher concentration, either face velocity or pulse interval should be reduced.

The change of pressure drop according to the change in the inlet concentration, pulse interval, and injection distance of pulse air jet type bag filters, and the effect of venturi installation are as follows. The pressure drop with the range of 30 to 50mmH2O varies according to the injection distance with 30, 50, 70, 90sec and the inlet concentration of venture built-in fabric filters. For the lower concentration of 0.5g/m3 and 1g/m3, the pressure drop(ΔP) was stable 60 to 90minutes after operation. For the higher concentration of 3g/m3, as ΔP continues to go up, pulse interval should be set shorter than 30 seconds. The pressure drop with the injection distance of 110mm, when inlet dust concentration is 0.5g/m3 or 1g/m3, is 1.3 to 2 lower than with the injection distance of 50, 160, and 220mm, which means that the inflow amount of the secondary air by the instant acceleration is large. The injection distance of 2g/m3 and 3g/m3 has the similar pressure distribution. The higher inlet concentration is, the more important pulse interval is than injection distance. The pressure drop has proved to be larger when inlet concentration is lower and injection distance closer, on condition that the venturi is installed. The change in the pressure drop was smallest when injection distance was 50mm, followed by 220mm, 160mm, and 110mm.