• Advances in Computational Design
• /
• v.5 no.3
• /
• pp.261-276
• /
• 2020

The reasonable layout of vacuum cleaner can effectively improve the collection efficiency of iron filings generated in the process of steel production. Therefore, in this study, the CFD-DEM coupling model and two-fluid model are used to calculate the iron filings collection efficiency of vacuum cleaner with different inclination/cross-sectional area, pressure drop and inlet angle. The results are as follows: The CFD-DEM coupling method can truly reflect the motion mode of iron filings in pneumatic conveying. Considering the instability and the decline of the growth rate of iron filings collection efficiency caused by high pressure drop, the layout of 75° inclination is suggested, and the optimal pressure drop is 100Pa. The optimal simulation results based on two-fluid model show that when the inlet angle and pressure drop are in the range of 45°~65° and 70Pa~100Pa, larger mass flow rate of iron filings can be obtained. It is hoped that the simulation results can offer some suggestion to the layout of vacuum cleaner in the rolling mill.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2001.04a
• /
• pp.17-29
• /
• 2001

• Journal of Biosystems Engineering
• /
• v.33 no.4
• /
• pp.230-238
• /
• 2008

Mechanization such as machine harvesting, precleaning, drying and cleaning for rapeseed harvested with high moisture content should be accomplished for biodiesel production. In addition, machine drying and cleaning is inevitable in the mechanization of work, just because rice should be transplanted right after harvesting rapeseed in Korea. Particularly, early harvested rapeseed with the combine have high moisture content and undesirable materials such as stalks and stones which make drying-process difficult and lower the efficiency of drying. Therefore, this study was conducted to develop precleaner and cleaner which could remove foreign substances from harvested rapeseeds. The precleaner consists of throw-in hopper, conveyor, feeding hopper, two precleaning sieves and discharging sections. Precleaning capacity was 1,505 kg/hr in shaking frequency of 370 cpm (cycles per minute) and tilt angles of between $5^{\circ}$ and $7^{\circ}$. The efficiency of precleaning was between 90.9% and 91.5%. The cleaner consists of feeding, shaking, blowing, cleaning and discharging sections. Cleaning performance was 435.4kg/hr in the number of rocking motions of 475 cpm and tilt angle of $10^{\circ}$. The ratios of cleaning, foreign substances and loss were 96.5%, 3.5% and 0.2%, respectively.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.6 no.3
• /
• pp.3-15
• /
• 2003

The concept of 'Cleaner Production(CP)' and various activities aiming at promoting CP are investigated along with the applicabilities of CP to marine environment. Although the conventional approaches dealing with the marine pollutions can be absorbed in CP, the whole activities of Production and conservation in the ocean must be projected into a new Paradigm, 'Sustainable Development.' Renewable energy is the first key to a complete CP and the ocean can provide us with the clew. In order to introduce CP system more effectively to marine environment opinion collection, environment monitoring, problem identification, resolution proposition, state-of-the-art evaluation, policy development, communication, education and public information are to be Planned and followed up systematically KOSMEE is believed to be a good structure to stand at the center of the upcoming CP activities in the ocean.

• Clean Technology
• /
• v.9 no.2
• /
• pp.63-69
• /
• 2003

The metal finishing industry generates a variety of pollutants such as acidic or alkaline wastewater, chromic compounds, cyanide, heavy metals, and toxic materials. Especially, zinc plating process is one of the processes which cause serious environmental problems. In this study, we applied the proven optimum technology to important unit processes in terms of implement effects through the process diagnosis and analysis. This study aimed to improve the working environment and the environmental pollutions in zinc plating process.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2000.04a
• /
• pp.82-83
• /
• 2000

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.939-942
• /
• 2007

Vacuum cleaner is a close life product that can remove various dusts from our surroundings. However well vacuum cleaner clean our environments, many people are looking away from it, due to its loud noise. Its noise causes a big trouble in the usual life, for example, catch calls, TV watching and discussing etc. To reduce these inconveniences, noise reduction methods and systematic design of low noise vacuum cleaner are studied in this paper. At first, sound quality investigation is performed to get the noise level and quality that make people TV watching and catch calls available. Based on the European and domestic customer SQ survey result, sound power, peak noise level and target sound spectrum guideline are studied and introduced. As a second, precise product sound spectrums are designed into each part based on the sound quality result. Fan-motor, brush, mainbody, cyclone spectrums are decided to get the final target sound based on the contribution level. Fan-motor is the major noise source of vacuum cleaner. Specially, its peak sound, RPM peak and BPF Peak, cause the people nervous. To reduce these peak sounds, high rotating impeller and diffuser are focused due to its interaction. A lot of experimental and numerical tests, operation points are investigated and optimization of flow path area between diffusers is performed. As a bagless device, cyclones are one of the major noise sources of vacuum cleaner. To reduce its noise, previous research is used and adopted well. Brush is the most difficult part to reduce noise. Its noise sources are all comes from aero-acoustic phenomena. Numerical analysis helps the understanding of flow structure and pattern, and a lot of experimental test are performed to reduce the noise. Gaps between the carpet and brush are optimized and flow paths are re-designed to lower the noise. Reduction is performed with keeping the cleaning efficiency and handling power together and much reduction of noise is acquired. With all above parts, main-body design is studied. To do a systematic design, configuration design developments technique is introduced from airplane design and evolved with each component design. As a first configuration, fan-motor installation position is investigated and 10 configuration ideas are developed and tested. As a second step, reduced size and compressed configuration candidates are tested and evaluated by a lot of major factor. Noise, power, mass production availability, size, flow path are evaluated together. If noise reduction configuration results in other performance degrade, the noise reduction configuration is ineffective. As a third configuration, cyclones are introduced and the size is reduced one more time and fourth, fifth, sixth, seventh configuration are evolved with size and design image with noise and other performance indexes. Finally we can get a overall much noise level reduction configuration. All above investigations are adopted into vacuum cleaner design and final customer satisfaction tests in Europe are performed. 1st grade sound quality and lowest noise level of bagless vacuum cleaner are achieved.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.3
• /
• pp.163-172
• /
• 2009

• Clean Technology
• /
• v.17 no.2
• /
• pp.181-188
• /
• 2011

In this study, the complementary or crowding-out effects of public R&D subsidy on private R&D investment in the cleaner production were analysed between the effects and the major determinants (company size, R&D investment intensity, ratio of government investment, R&D manpower intensity). Among 207 firms' projects, the number of the complementary effect was 95 (45.9%) while that of crowding-out effect was 38 (18.4%). Resulting from logistic regression, the higher the R&D investment of sponsored companies is, the more complementary effect they show, responding to public R&D subsidy, and increase own R&D investment. The other determinants, however, showed no significant effects on firms' R&D investment. To heighten the effect of public cleaner production R&D, it is need to increase the priority of R&D investment intensity among the determinants. And to increase the performance of governmental R&D investment, further studies for the individual public R&D programs are necessary.

• Clean Technology
• /
• v.9 no.1
• /
• pp.1-8
• /
• 2003

In order to implement clean technology to Petro-chemical process, simulation package of given process should exist. In this paper, reaction and recycling parts of a process are explained using EA process and MEK process respectively so as to explain how to make simulation package. Based on simulation package, several options are generated and feasibility tests are performed.