• Environmental Engineering Research
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• 제24권4호
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• pp.529-542
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• 2019

Nowadays, drying methods for municipal solid waste quality improvement have been adopted in the developed and developing countries to valorize wastes for a renewable energy source, reduce dependency on fossil fuel and keep safer disposal at landfills. Among them, biodrying, biostabilization, thermal drying and solar drying are the most common. Drying of municipal solid waste could offer several environmental and economic benefits. Therefore, this review highlighted the drying methods for municipal solid waste quality improvement around the world and compared them based on the reduction of moisture, weight and volume of municipal solid wastes against drying temperature and time by using statistical analysis. It was observed that the drying temperature of different drying methods accounted for 115 ± 40℃ for thermal drying, 59 ± 37℃ for solar drying, 55 ± 15℃ for biodrying and 58 ± 11℃ for biostabilization. Among the drying methods, thermal drying provided the shortest drying time. The moisture reduction, weight reduction, volume reduction and heating value increase of municipal solid waste could vary with drying temperature and time. Finally, the benefits and drawbacks of different drying methods were specified, and recommendations were made for the future efficient drying.

• 유기물자원화
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• 제13권2호
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• pp.74-84
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• 2005

본 연구의 목적은 열풍건조를 이용하여 슬러지를 감량화하는 과정에서 발생되는 열적거동을 조사하는데 있다. 실험에서 중요한 운전매개변수는 공급되는 건조온도가 $130{\sim}170^{\circ}C$와 증발속도 WD를 변화시켜 실행하였다. 슬러지내 수분을 증발하는 과정에서 열적거동의 변화에 미치는 영향인 주요매개 변수는 공급되는 온도변화에 따른 건조시간, 슬러지내 수분함량, 슬러지의 고형물량에 따른 결과를 조사하였다. WD=0.95m/s의 조건에서 $170^{\circ}C$의 건조온도에서 수분이 증발되는 포화점은 95분과 $130^{\circ}C$에서 120분에서 조사되었다. 열풍의 의한 증발속도가 1.0 m/s로 일정할 때 건조온도가 130와 $150^{\circ}C$일 때 보다 $170^{\circ}C$인 경우가 증발율이 더 높게 나타났고, 건조기 온도가 $130^{\circ}C$인 경우는 WD=1.0 m/s일 때 WD=0.5 m/s 보다 증발율이 높게 나타남을 볼 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.23-28
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• 2007

Wood fuel must be dried before combustion to minimize the energy loss. Sawdust of Japanese red pine was dried in a direct contact thermal screw dryer to investigate the drying characteristics of sawdust as a raw material for bio-fuel. Average drying rate and energy efficiency was 1.4%/min and 69.23% at $100^{\circ}C$, respectively, and those at $120^{\circ}C$ was 2.1%/min and 71.03%, respectively.

• 동력기계공학회지
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• 제5권1호
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• pp.44-49
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• 2001

Low temperature vacuum drying technique shows very excellent energy efficiency and prominent drying performances compared with the conventional hot air drying technique. This study was focused on the thermal characteristics of the low temperature vacuum drying technique. From the results of this study, it was confirmed that the time consumption for drying with the new drying technique could be shortened to about 1/3 of the time consumption with the conventional hot air drying technique under the same drying conditions for wet products. Also, the maximum drying rate with the new drying technique reached to about $0.35kg/m^2h$ at about 400% of moisture content.

• Journal of the Korean Wood Science and Technology
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• 제26권4호
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• pp.34-42
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• 1998

Three hardwood (ash, alder and black locust) and three softwood (Japanese red pine, radiata pine and Western hemlock) specimens were dried in microwave(MlW) oven and their drying rates were obtained. Their specific permeabilities were also measured by using a modified liquid permeability measuring device. The correlation between the M/W drying rates and permeabilities of six species were statistically analyzed. It was revealed that within a species there is a logarithmic relationship between the M/W drying rates and average moisture contents and that among species there is a linear relationship between the M/W maximum drying rates and the average specific permeabilities. A exception was Western hemlock, which was of low permeability and of high drying rate. A Me-time equation, which showed a good agreement with the actual data, was derived. Thus using this equation the moisture contents of wood and the drying end points of M/W drying could be predicted. Infrared images of the thermal distribution in wood were illustrated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.589-590
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• 2010

The drying method that is applied in industry is mainly used hot air drying method witch is circulated heated air by generating heat from thermal source. But these methods have problems such as decreasing drying efficiency and waste of energy by low thermal efficiency. Therefore, this paper proposes high efficiency hybrid drying system using near infrared ray(NIR) drying method using halogen lamp and hot air drying method. And this paper proves validity of proposed drying system through experiment about thermal and humidity of drying system inside.

• 태양에너지
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• 제9권2호
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• pp.14-21
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• 1989

The heat transfer analysis is performed on unloaded solar utilization dryer, and thermal performance for a prototype model while drying red-pepper is also investigated. Results of theoretically derived thermal equations are in good agreement with experimental data. This constructed feature of the prototype demonstrates the excellent technical drying performance. Finally, this paper recommends the further work to develop advanced and economic solar utilization multi-purpose dryer.

• 설비공학논문집
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• 제22권12호
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• pp.828-836
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• 2010

The drying is a process that involves coupled and simultaneous heat and mass transfer. When a wet solid is subjected to thermal drying, two processes occur simultaneously. Drying is classified according to heat transfer characteristics in terms of conduction, convection and radiation. In thermal drying, radiation is easier to control than conduction and convection drying and involves a relatively simple structure. In this study, we measured energy consumption, surface hardness of paint and surface gloss with variation of surface temperature of drying materials and drying time. Drying characteristics and energy consumption between heating panels and hot air heating have been presented. The present study shows that a dryer using heating panels is more effective than a hot air dryer from the viewpoint of energy conservation. The hot air dryer, however, was not optimized and more studies on various parameters related to drying will need to be investigated for definite comparison of drying characteristics of the dryers. The result, even if limited, would present the effective availability of paint drying.

• Journal of Welding and Joining
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• 제14권6호
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• pp.101-108
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• 1996

In this study, WC-l7wt% Co composite powder for thermal spray was fabricated by spray drying method. The agglomerated composite powder had spheroidal morphology and the particle size distribution was 20~60${\mu}{\textrm}{m}$. WC and Co were distributed homogeneously. However, the strength of the spray-dried agglomerate was low due to the pores within the agglomerate. Therefore, the spray-dried agglomerate was broken down during HVOF thermal spray and the microstructure was inhomogeneous with many pores within the coating layer. And the decomposition of WC to W and $W_{6}$ $C_{2.54}$ was accelerated. The strength and flowability of the agglomerate were greatly improved by sintering heat treatment(110$0^{\circ}C$, 1 hour, hi atmosphere), and then the coating layer showed dense and homogeneous microstructure with well-developed splats. The hardness of the coating layer was H $v_{300}$ = 1072.2.2.

• 태양에너지
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• 제11권3호
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• pp.9-20
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• 1991

무우절편의 태양열건조 및 천일건조 실험을 수행하여 건조 특성 및 품질 변화 특성을 비교하여 분석하였다. 무우절편의 태양열 건조 시스템은 공기 가열식 태양열 집열기와 터널 건조실로 구성된다. 태양열 집열기의 구성 요소에 에너지 평형식을 적용하여 일사량과 송풍량의 변화에 따른 집열기의 집열성능을 분석할 수 있는 시뮬레이션 모형을 개발하였다.