• Title/Summary/Keyword: hot-air drying method

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Numerical Analysis of the Inner Flow of a 3-pass Rotary Dryer (3단 회전식 건조기의 내부 유동에 관한 수치해석)

  • Kim, T.S.;Kim, Y.K.;Choi, Y.H.;Choi, K.;Lee, Y.W.
    • Journal of Power System Engineering
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    • v.9 no.4
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    • pp.51-57
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    • 2005
  • In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Generally, the drying method is various as to the property of material and use. Rotary dryer is a good apparatus to treat them. The rotary dryer is the way that is to make substance transmission and heating using hot air between sludge particles and heated gas. In this paper, we performed a numerical analysis of the inner air flow of the 3-pass rotary dryer through the changing rotational speed from 3rpm to 10rpm. In this result, we found that 3rpm is effective to dry material in terms of heat transfer because large scale velocity fluctuation is occurred inside the first and second drum. Also we confirmed that 5rpm and 8rpm showed up uniform flow at the center area of the first drum.

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Making Techniques of Hight Quality Powder in Sweetpotato (고구마 고품질 분말 제조기술)

  • Lee, Joon-Seol;Ahn, Young-Sup;Kim, Hag-Sin;Chung, Mi-Nam;Jeong, Byeong-Choon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.198-203
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    • 2006
  • This study was conducted to select the temperature for hot air drying method, cutting method, and solution that inhibits enzymatic browning in making high quality powder from sweetpotato roots. It was observed that $70^{\circ}C$ was the best temperature for air drying method wherein the dry matter rating, dry matter time, flour yield and chemical component were considered. The proper cutting thickness should be 2.0 mm considering the vitamin C content and sensory evaluation of sweetpotato flour. Also, 1% vitamin C solution inhibited enzymatic browning of sweetpotato.

Sensory Characteristics of Dehydrated Ginger Rhizomes Prepared using Recycled Dehydrating Liquid as an Alternative Dehydrating Agent (재사용 탈수액을 탈수제로 이용한 생강의 탈수 및 품질특성)

  • Lee, Hyun-Seok;Kwon, Ki-Hyun;Kim, Byeong-Sam;Cha, Hwan-Soo
    • Food Science and Preservation
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    • v.17 no.3
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    • pp.358-364
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    • 2010
  • Ginger was dried using maltodextrin or recycled dehydration liquid as dehydrating agents, and the quality of dried ginger was compared with that of freeze-dried and hot-air-dried samples in terms of color, moisture content, water activity, dehydration rate, rehydration rate, and sensory properties. Ginger prepared using molecular press dehydration (MPD) retained its original color. The dehydration rate increased when ginger was dried using a dehydrating agent. The rehydration rate was increased in ginger dried using such an agent. Both dehydration and rehydration rates were elevated with increasing concentrations of soluble solids in the dehydration liquid. The sensory qualities of ginger prepared using the MPD method were better than those of freeze-dried and hot air-dried samples. These results indicate that drying of ginger rhizomes using recycled dehydrating liquid is very efficient.

The Formation of Cholesterol Oxidation Products during Its Drying and Cooking in Squid (오징어 건조 및 조리 중 콜레스테롤 산화물 생성)

  • Yang, Seung-Mi;Shin, Jung-Hye;Kang, Min-Jung;Kim, Tae-Hoon;Sung, Nak-Ju
    • The Korean Journal of Food And Nutrition
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    • v.14 no.6
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    • pp.573-578
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    • 2001
  • Cholesterol oxidation products(COPs) such as 7-ketocholesterol, 7 ${\alpha}$, 7 ${\beta}$-hydroxycholesterol and 25-hydroxycholesterol were analyzed for ensuring the safety of squid during its drying and cooking. In addition. changes of malonaldehyde in squid during its drying and cooking were also investigated. Cholesterol was detected 636.4m9/1009 in fresh sample, which was decreased during its drying and cholesterol contents in dried sample were 468.9mg/100g, 486.8mg/100g, respectively, while COPs contents of sun and hot air dried samples increased about 6.2 times more than those contents of fresh sample. Regardless of cooking methods, the contents of COPs in dried products increased after cooking. Especially, those contents were determined 127.3 mg/g in sun dried samples were cooked by microwave oven. The malonaldehyde contents of dried products increased after cooking, its contents in cooked samples by an microwave oven after sun dried were about 4.3 times more than in control products. In general, a small quantity of COPs were formed in dried samples which were cooked by a steam.

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Effect of Maltodextrin and Recycled Dehydration Liquid on the Quality Characteristics of Green Pepper (Maltodextrin과 재사용 탈수액이 고추의 품질에 미치는 영향)

  • Lee, Hyun-Seok;Kwon, Ki-Hyun;Kim, Jong-Hoon;Kim, Byeong-Sam;Cha, Hwan-Soo
    • Food Science and Preservation
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    • v.16 no.6
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    • pp.843-848
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    • 2009
  • Green peppers were dried using maltodextrin and recycled dehydration liquid as dehydrating agents, and the quality of dried green pepper powders was compared with that of freeze-dried and hot air-dried samples in terms of moisture content, color, antioxidant activity, capsaicinoid level, and sensory acceptability. The moisture content of maltodextrin-treatedgreen pepper powder was higher than that of samples prepared using recycled dehydration liquid. The lightness (L) value rose with increasing concentrations of maltodextrin powder or liquid. The antioxidant activities of pepper powders prepared using the molecular press dehydration method were similar to that of alpha-tocopherol, and better than that offreeze-dried or hot air-dried samples. Capsaicinoid levels fell with increasing concentrations of maltodextrin powder and liquid. The sensory evaluation data on green pepper powders prepared using the molecular press dehydration method were better than those obtained when freeze-dried and hot air-dried samples were evaluated. These results indicate that drying of green pepper powders using maltodextrin and recycled dehydration liquid as dehydrating agents is very efficient.

Development of Samgyetang Broth from Air-dried and Oven-roasted Chicken Feet (열풍건조 및 오븐구이 닭발로부터 추출한 삼계탕 육수 제조)

  • Kim, Juntae;Utama, Dicky Tri;Jeong, Hae Seong;Heidar, Barido Farouq;Jang, Aera;Pak, Jae In;Kim, Yeong Jong;Lee, Sung Ki
    • Korean Journal of Poultry Science
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    • v.46 no.3
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    • pp.137-154
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    • 2019
  • This study was conducted to develop and compare Samgyetang broth from extract of pre-treated chicken feet. Chicken feet were subjected to non-heating (control), heating at $70^{\circ}C$ for 12 h in a hot air dryer, and heating at $180^{\circ}C$ for 1 h in an oven. The heat-treated chicken feet were extracted at $121^{\circ}C$ for 1 h and 2 h, respectively. The extract was placed in a pouch with whole chicken carcass ($470{\pm}10g$). The sealed Samgyetang retort was made according to the industrial method. The pH of the extract from preheated chicken feet was lower than that extracted from fresh chicken feet. The Thiobarbituric Acid Reactive Substances (TBARS) value of the preheated chicken feet extract was significantly lower (P<0.05) than that of fresh chicken feet extract, but there were no significant differences among the broths. As the extraction time increased, the pH and TBARS value decreased in the extract (P<0.05) but increased in the broth (P<0.05). According to the sensory evaluation test, the extract from 1 h hot air heating and drying was significantly better in appearance, aroma, and overall preference than the other treatments (P<0.05). The GC-MS results showed that benzaldehyde and benzothiazole, which are widely known to give meat and nuts flavor, were detected in those treatments (P<0.05). The Samgyetang broths prepared from 1 h hot air heating and drying extract were significantly higher in the overall acceptability according to the sensory test (P<0.05). In summary, the quality of retort Samgyetang broth can be improved by adding chicken feet extract which is subjected to heating and drying for 1 h.

A Study on Real-Time Monitoring for Moisture Measurement of Organic Samples inside a Drying Oven using Arduino Based on Open-Source (오픈 소스 기반의 아두이노를 이용한 건조기 내 유기 시료의 실시간 수분측정 모니터링에 관한 연구)

  • Kim, Jeong-hun
    • Journal of Venture Innovation
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    • v.5 no.2
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    • pp.85-99
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    • 2022
  • Dryers becoming commercially available for experimental and industrial use are classified to general drying oven, hot-air dryer, vacuum dryer, freezing dryer, etc. and kinds of them are various from the function, size and volume, etc. But the moisture measurement is not applied although it is important factor for the quality control and the performance improvement of products, and then now is very passive because the weight is weighed arbitrarily after dry-end. Generally the method for measuring moisture is divided by a direct measurement method and a indirect measurement method, and the former such as the change of weight or volume on the front and rear of separation of moisture, etc. is mainly used. Relatively a indirect measurement is very limited to apply due to utilize measurement apparatuses using temperature conductivity and micro-wave etc. In this research, we easily designed the moisture measurement system using the open-source based Arduino, and monitored moisture fluctuations and weight profiles in the real-time without the effect of external environment. Concretely the temperature-humidity and load cell sensors were packaged into a drying oven and the various change values were measured, and their sensors capable to operate 60℃ and 80℃ were selected to suitable for the moisture sensitive materials and the food dry. And also the performance safety using the organic samples of banana, pear, sawdust could be secured because the changes of evaporation rate as the dry time and temperature, and the measurement values of load cell appeared stable response characteristics through repeated experiments. Hereafter we judge that the reliability can be improved increasingly through the expansion of temperature-humidity range and the comparative analysis with CFD(Computational Fluid Dynamics) program.

Aroma Characteristics of Pholiota adiposa (Geumbongi) with Different Drying Methods (건조방법에 따른 검은비늘버섯의 향기특성)

  • Yoon, Hyang-Sik;Oh, Eun-Hee;Joo, Seon-Jong;Kim, Ki-Sik;Jeong, Eun-Kyeong;Chang, Who-Bong;Kim, Sook-Jong
    • Korean Journal of Food Science and Technology
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    • v.36 no.4
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    • pp.553-557
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    • 2004
  • Aroma compounds in Pholiota adiposa were extracted by simultaneous distillation and extraction (SDE), and 41 compounds were identified by GC-MS, including eleven alcohols, eight aldehydes, four esters, four ketones, nine alkans, and five miscellaneous compounds. Major aroma compounds included hexanal (8.55%), n-heptaldehyde (13.02%), 2-pentyl furan (4.82%), benzeneacetaldehyde (3.34%), (E,Z)-2,4-decadienal (3.06%), and hexacosane(5.04%). Drying method was applied to aroma compounds of Pholiota adiposa extracted by solid phase microextraction and identified by GC-MS. As hot air-drying temperature increased, peak areas (%) of 2-phenylethanol and benzeneacetaldehyde decreased, whereas those of 2(5H)-furanone (0.16%), 2H-1-benzopyran-2-one (7.63%), 2-acetylpyrrole (5.49%), and 4-phenyl-pyridine (5.61%) increased significantly at $70^{\circ}C$.

A study on the color controlled of painter's work (페인트 도장공사의 색관리에 관한 연구)

  • Shim, Myung-Sup;Lee, Hyun-Jeong
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.1
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    • pp.107-114
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    • 2003
  • This study aims to find methods that prevents aging of buildings paint coating and that limits defects in construction. Defects in painting can occur in four stages: pure paint, during painting, after the paint coating has dried, and after some period of time has passed after coating. Paint may become bad due to precipitation of pigments, formation of membranes, and seeding during manufacturing. Therefore, it is important that the paint is well mixed and kept airtight at a cool, dark place. Indents, paint brush strokes, orange peel, separation of colors, and paint running and spreading during the paint work process can be prevented by using high quality materials and applying a high-level of construction method. After the paint coating has dried, boiling, yellowing, poor drying, poor bonding, and/or glen deficiency may occur. These are influenced by the levels of cleanness of the dried product, drying temperature and hydration. Then, when the coating has been left dried for some period of time, cracking, peeling, scaling, swelling, discoloring, and/or rusting may develop due to the ultraviolet and contaminants in the air. Since these defects occur due to inappropriate construction schedule and/or hot and humid condition, one must use weatherproof materials. Furthermore, poor paint color may be caused by contamination in the sample plate, discoloration, and/or discrepancies in colors which are due to material differences, level of glossiness, degree of dispersion, dual color property of metallic colors, precipitation of pigments, etc. One should achieve reduction in construction cost and effectiveness in paint work by limiting contaminations in the construction site and strictly observing to construction regulations.

Study on Optimum Installation of Fan in Standard Hanwoo Loose Barn (한우사 내 송풍팬의 최적 설치에 관한 연구)

  • Lee, Seung-Joo;Chang, Dong-Il;Choi, Yoon-Hyuck;Yang, Jae-Woong;Min, Byeong-Joo;Gutierrez, Winson M.;Chang, Hong-Hee
    • Journal of Biosystems Engineering
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    • v.35 no.5
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    • pp.350-356
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    • 2010
  • The fans installed in standard Hanwoo loose barns (room size : 10 m (width) $\times$ 5 m (length)) are frequently used to reduce Hanwoo's heat stress during hot weather and to dry the wet floor. However, the most effective method of installing fans has not been suggested yet. Therefore, this study was carried out to evaluate two methods of installing fans under the ceiling of Hanwoo loose barn by using CFD (Computational Fluid Dynamics) code, FLUENT and to recommend the optimum fan installing method. The fan installation options were fan tilting angles of $45^{\circ}$ and $0^{\circ}$ (horizontal). The fans of 1 m diameter were installed at 3 m above floor. A velocity scale on 10 cm and 110 cm above floor and air flow pattern were used as the parameters to evaluate the fan installing methods. The fans tilted at $45^{\circ}$ angle produced higher wind at 10 cm and 110 cm above floor and more uniform air flow pattern, compared with the fans installed horizontally. Based on these results, fans tilted at $45^{\circ}$ angle may help to reduce Hanwoo's heat stress and will dry the floor better than fans installed horizontally. Therefore, it is suggested that the fans of 1 m diameter in a standard Hanwoo loose barn should be installed at a $45^{\circ}$ tilt angle and 3 m above floor with spacing of 5 m at the center of a room column.