• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.101-106
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• 2017

The chemical mechanical planarization (CMP) process combines the chemical effect of slurry with the mechanical effect of abrasive (slurry)-wafer-pads The slurry delivery system has a notable effect on polishing results, because the slurry distribution is changed by the supply method. Thus, the investigation of slurry pumps and nozzles with regard to the slurry delivery system becomes important. This paper investigated the effect of a centrifugal slurry pump on a spray nozzle system in terms of uniform slurry supply under a rotating copper (Cu) wafer, based on experimental results and computational fluid dynamics (CFD). In conventional tools, the slurry is unevenly and discontinuously supplied to the pad, due to a pulsed flow caused by the peristaltic pump and distributed in a narrow area by the tube nozzle. Adopting the proposed slurry delivery system provides a higher uniformity and lowered shear stress than usual methods. Therefore, the newly developed slurry delivery system can improve the CMP performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.567-568
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• 2006

To investigate the recycle possibility of slurry for the oxide-chemical mechanical polishing (oxide-CMP) application, three kinds of retreated methods were introduced as follows: First, the effects on the addition of silica abrasives and the diluted silica slurry (DSS) on CMP performances were investigated. Second, the characteristics of mixed abrasive slurry (MAS) using non-annealed and annealed alumina ($Al_2O_3$) powder as an abrasive added within DSS were evaluated to achieve the improvement of removal rates (RRs) and within-wafer non-uniformity (WIWNU%). Third, the oxide-CMP wastewater was examined in order to evaluate the possible ways of reusing it. And then, we have discussed the CMP characteristics of silica slurry retreated by mixing of original slurry and used slurry (MOS).

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.784-791
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• 2000

To improve the uniformity of slurry spreading and to reduce the odor problem, a hose slurry spreader was developed, which spread the slurry near to the surface of the soil. First, the uniformity of slurry spreading was investigated. The best result of 8.1 ％ CV was obtained at the rotor speed of 250 rpm than any other speeds for the swine slurry, which contains 13.6% of dry matter. In case of dairy cattle slurry, which contains 8.2% of dry matter, the uniformity has the best result of CV 7.2% by high rotor speed of 330 rpm. A high speed of rotor has built a sufficient pressure in the distributor and discharged a uniform quantity of slurry through the hoses. Therefore, in practical use one should work with rotor speed over 300 rpm to maximize the uniformity of slurry spreading. Second, odor test was done with the swine slurry. While the conventional spreader shows ∑ value 440, the hose slurry spreader and its combination of disk harrow show ∑ value 258 and 184 respectively. With the air dilution sensual test and a 3-point odor bag, the conventional spreader shows 66.9 or 35.4 point and by the hose slurry spreader is 9.7 or 11.1 point. So, the developed spreader was found to have a greater effect on the reduction of odor problem. Finally, it is recommended to spread certain amount of the slurry for paddy field equivalent to the chemical fertilizer based on the N-content. It means 22 tons of swine slurry per ha. Since most of the livestock farms possess less arable land, a system of linking farms is necessary to utilize the slurry crossover the farms. The cost of slurry utilization including filling, transport spreading and brokerage is 3200-6800 Won/㎥ in accordance with the transport distance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.219-225
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• 2005

To investigate the effects of slurry temperature on the chemical mechanical polishing(CMP) performance of oxide film with silica and ceria slurries, we have studied slurry properties as a function of different slurry temperature. Also, the effects of each input parameter of slurry on the oxide CMP characteristics were investigated. The pH showed a slight tendency of decrease, the conductivity in slurries showed an increased tendency, the mean particle size in slurry decreased, and the zeta potential of slurry decreased with temperature. The removal rates significantly increased and maintained at the specific levels over 4$0^{\circ}C$. The better surface morphology of oxide films could be obtained at 40 $^{\circ}C$ of silica slurry and at 90 $^{\circ}C$ of ceria slurry. It is found that the CMP performance of oxide film could be significantly improved or controlled by change of slurry temperature.

• Journal of Applied Reliability
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• v.16 no.4
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• pp.263-271
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• 2016

Purpose: A slurry pump for flue gas desulfurization system performs a role that discharges the slurry of a plaster shape in a thermal power plant. Since a slurry pump transfers the slurry by the centrifugal force, it has the friction wear in the impeller and liner because of the slurry. Methods: In this study, failure analysis and test evaluation on the slurry pump have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement design has been presented. Results: Reliability improvement is established by analysis of the test results of before and after acceleration test. Conclusion: This study can be provided to improve the product reliability through failure analysis of a slurry pump.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.4
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• pp.478-486
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• 2007

Numerical analysis had been performed to understand flow characteristics of the flue gas and slurry in the absorber of a flue gas desulphurization (FGD) system using computational fluid dynamics (CFD) technique. Two-fluid(Euler-Lagrangian) model had been employed to simulate physical phenomenon, which slurry particles injected through slurry spray nozzles fall down and bump into the flue gas inflowing through inlet duct. It was not necessary to adopt pre-defined pressure drop inside the absorber because interaction between flue gas and slurry particles was considered. Hundreds of slurry spray nozzles were considered with the spray velocity at the nozzles, swirl velocity and spreading angle. The results note that the flow disturbance of flue gas is found at the bottom of the absorber, and the current rising with high speed stream is observed in the opposite region of the inflow duct. The high speed stream is reduced as the flue gas goes up, because the high speed stream of flue gas dumps falling slurry particles due to momentum exchange between flue gas and slurry particles. In spite of some disproportion in slurry distribution inside the absorber, escape of slurry particles from the absorber facility is not observed. The pressure drop inside the absorber is mainly occurred at the bottom section.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.380-381
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• 2006

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, we studied the mixed abrasive slurry (MAS). In order to save the costs of slurry, the original silica slurry was diluted by de-ionized water (DIW). And then, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry for the oxide CMP application.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.64-70
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• 2007

Preparation and characterization of carbon-slurry fuel with high dispersion have been carried out. Carbon-slurry fuel was obtained by mixing Jet A-1 liquid fuel with appropriate carbon powders and additives. Dispersion of carbon in Jet A-1 was affected by various factors such as mixing temperature, characteristics of carbon powders, and type and amount of additives. Among these factors, the stability of the slurry fuel was most dependent on the type of additive. A variety of additives such as anionic, cationic, and nonionic additives was tested for the dispersion of carbon in Jet A-1. It was found that anionic additives based on sodium salts showed the highest dispersion of carbon-slurry fuels. The degree of dispersion could be monitored by measuring the luminosity.

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.93-97
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• 2016

Purpose: Grain slurry diet are described as food obtained from ground grain paste. They serve as highly nutritious food for both adults and infants in Nigeria because of their immense nutritive and economical value. However, the production of these grain slurry diets is confronted with challenges that have hampered their commercialization. This study examines the trends and constraints of grain slurry food processing in Kaduna State. Methods: A survey was conducted using a structured questionnaire to elicit information from 192 selected processors, including both men and women. The survey was structured in line with the study objectives. The information was collated and synopsized into frequency distribution. Results: These findings revealed that 80% of the respondents processed between 1.0 tons and 13.0 tons of grain slurry per month. More than 90% of the processors processed grain slurry into koko, kunu, agidi, and pito. Accordingly, 80% of the interviewed processors indicated that sieving is one of the major constraints. Furthermore, inadequate modern machinery required to perform this operation makes it highly discouraging. One of the major challenges faced by the grain slurry producers in Nigeria is the lack of processing machinery for most operations (39.1%), followed by the tedious processing nature (27.1%), high labor cost (18.1%), and lack of market (9.4%). The traditional method of grain slurry processing was more popular than using modern equipment, except milling (96.5%), which is the only mechanized unit operation in grain slurry processing. Conclusion: Grain slurry processing and marketing were found to be profitable. However, these limitations could extremely reduce the level of grain slurry production, processing, and economic returns, thereby affecting the general wellbeing of the processors. The study also raised concerns about the safety and hygiene associated with traditionally processed grain slurry diets in the investigated areas.

• Journal of Biosystems Engineering
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• v.30 no.1 s.108
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• pp.32-37
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• 2005

This study was conducted the slurry pig manure treatment by condensation drying of liquid from the slurry manure with a heat-pump and electric heater combined with air flow channel system. The system was designed as liquid and solid matters separation of slurry manure, and it can doing continuous input of slurry manure from a pig house, and it can operated year round use for pig farms. The separation of liquid and solid matters from slurry manure needed the prevention of solid accumulation in the system. The system was designed as closed space from outside air space for maximized evaporation of liquid and the condensation of liquid from slurry manure. The system can be operated the pig slurry manure treatment regardless of seasons in a yew. The separated evaporation water from the pig slurry manure by the heat-pump was satisfactorily pure water that can be used as washing water in livestock farms. The system can applicate to about 100 heads of pig, and the proper area of evaporation plate system was considered around $10\;m^2$. The input electrical energy of about 15 kWh which the cost equal to 250,000 won per month.