Drying Characteristics and Energy Analysis of Food Waste Dryer using Steam from Incineration Plant

Dae-Bin Song,Ki-Hyeon Lim,Dae-Hong Jung,Jong-Hyun Yoon 경상대학교 농업생명과학연구원 2020 농업생명과학연구 Vol.54 No.3

This study was conducted to develop a high-moisture food waste dryer that uses steam as a direct heat source to improve the drying speed. Another objective was to verify its performance through experiments. A dryer with a drying capacity of 10,000 kg/hr, which uses steam from an incineration plant as a drying heat source, was fabricated. The performance and applicability of the dryer were verified through drying experiments, in which the food waste collected from large restaurants near the incineration plant was used as the experimental material. The drying experiment results showed that the input steam temperature increased by 21℃ from approximately 145℃ to 166℃ compared to the case in which drying was performed by converting steam into heated air. The drying speed increased by 1.5 times from approximately 0.63 to 0.94 %/hr, and drying up to approximately 20%(wb) moisture content was possible. The drying energy rate, which represents the ratio of the energy consumed for drying to the input energy, increased by approximately ten times from 7.17% to 70.87%. The total drying time still remained approximately 100 hr due to the re-condensation of moisture. When steam was directly used as a drying heat source to improve the drying speed of food waste containing high moisture, the drying speed, water content after drying, and drying energy rate were clearly improved compared to the case in which steam was converted into heated air for use. Therefore, it was deemed necessary to develop a dryer that directly uses steam from an incineration plant for drying. To shorten the total drying time, it is necessary to develop a device that solves the problem of moisture condensation in the dryer.

Drying Characteristics and Models of Red Ginseng Slice Using Far-Infrared Rays

Ning Xiao Feng,Xu Ji Tong,장문기 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.4

Purpose The aim of this study was to improve the drying quality and find the suitable drying model for the far-infrared drying of red ginseng slice. Methods The far-infrared drying tests on ginseng slice were conducted at two slice thickness of 2 and 4 mm and three drying temperatures of 50, 60, and 70 °C. The results were compared with the hot air drying method. The drying characteristics were analyzed based on factors such as drying rate, color changes, and elastic modulus. The Page, modified Wang and Singh, and logarithmic models were used to select the best model for far-infrared drying of red ginseng slices. Results The results revealed that increasing drying temperature and decreasing ginseng thickness caused a decrease in drying time. The color differences (ΔE) at 70 °C values were higher than 50 and 60 °C values. The highest elastic modulus (32.42 MPa) was observed at drying temperatures of 60 °C ginseng slice of 4mm. The drying quality of far-infrared dryingwas better than that of hot air drying under the same drying condition. The Page model showed the highest R2 values and lowest RMSE values than the other models. Conclusion The quality of red ginseng slice can be improved by far-infrared drying. The Page model was the best model to fit adequately most of the drying conditions for the far-infrared drying of red ginseng slice.

논문 : 생물생산시설 및 환경공학 ; 원적외선과 열풍 건조조건에 따른 오징어의 건조특성

강태환 ( T. H. Kang ),홍현기 ( H. K. Hong ),전홍영 ( H. Y. Jeon ),한충수 ( C. S. Han ) 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.2

Drying characteristics of squids under two dry conditions were investigated using far infrared and heated air. Dry temperatures of 40, 50 and 60℃ with air speed of 0.6, 0.8 and 1.2 m/s were used for evaluating far infrared squid drying. Heated air squid drying at 40 and 50℃ with air speed of 0.8 m/s was used as a control treatment. The two drying were evaluated in terms of drying rate, color, TBA value, aerobic bacteria, cutting shear, penetration strength, and energy consumption. The drying rate of far infrared drying was relatively faster than that of heated air drying. The drying time of far infrared drying was reduced as the drying temperature increased. The color difference of far infrared dried squids was from 18.81 to 22.85, and heated air dried squid had the color different from 23.94 to 24.09. Far infrared dried squid had relatively smaller TBA values that indicate a level of rancidity. The aerobic bacteria of heated air dried squid increased from 970×10(3) to 40,000×10(3) CFU/g before and after drying, respectively. Far infrared dried squid had relatively smaller increase (from 970×10(3) to 40,000×10(3) CFU/g). The cutting shear and penetration strength for far infrared dried squids was relatively lower. In addition, far infrared squid drying consumed relatively less energy compared to heated air drying.

Determination of Drying Characteristics of Radish under Microwave Drying

( Dong Young Lee ),( Hyung Gyu Park ),( Choi Woo Bin ),( Seung Hyun Lee ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.2

Dried agricultural product have received a great attention from consumers because of easy use for cooking. Several drying technologies such as hot air, vacuum, infrared, and freezing have been widely applied in commercial sites for producing dried products but have inherent limitation for retaining nutritional values and color. Combination drying technology has been developed for overcoming limitation and producing high quality dried agricultural product; however, there was a lack of research regarding microwave drying mechanism for specific agricultural products. Therefore, this study was intended to investigate microwave drying characteristics of radish. The domestic microwave oven was modified for microwave drying. The outlet fan was installed on the left upper side of the microwave oven for removing water vapor during the drying process. The applied microwave power levels for drying experiments were from 90 W to 900 W with interval of 90 W. Samples were cut into two fixed size shred shape (6 and 9 mm in thickness). Six well-known drying models were examined to select the suitable model for describing microwave drying curve of radish. A non-linear regression analysis was used to calculate model parameters and indices. The models were compared based on the coefficient of correlation and root mean square error. The results showed that drying time was decreased with an increase in microwave power. However, the dried product dried by 900 W was significantly shrink and indicated the worst value in terms of color. The Page model was in a good agreement with experimental drying data. The effective moisture diffusivity changes obtained from Fick’s diffusion method was between 8.98X10^-10m²/s and 2.010X10^-8m²/s. The moisture diffusivity was increased with an increase in microwave power.

Drying methods for municipal solid waste quality improvement in the developed and developing countries: A review

Maw Maw Tun,Dagmar Juchelkova 대한환경공학회 2019 Environmental Engineering Research Vol.24 No.4

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.

Drying characteristics and quality of red ginseng using far-infrared rays

Ning, Xiaofeng,Lee, Junsoo,Han, Chungsu The Korean Society of Ginseng 2015 Journal of Ginseng Research Vol.39 No.4

Background: The current typical drying methods for red ginseng are sun drying and hot-air drying. The purpose of this study was to investigate drying characteristics of red ginseng by using far-infrared drying. Methods: The far-infrared drying tests on red ginseng were conducted at two drying stages: (1) high temperature for 24 h drying and (2) low temperature drying until the final moisture content was $13{\pm}0.5%$ (wet basis). The high temperature drying stage included three drying chamber temperature conditions of $60^{\circ}C$, $65^{\circ}C$, and $70^{\circ}C$. The low temperature drying stage was conducted at temperatures of $45^{\circ}C$ and $50^{\circ}C$. Drying characteristics were analyzed based on factors such as drying rate, color changes, energy consumption, and saponin content. The results were compared with those of the hot-air and sun drying methods. Results: The results revealed that increases in drying temperature caused a decrease in drying time and energy consumption for far-infrared drying. The saponin content decreased under all drying conditions after drying, the highest value (11.34 mg/g) was observed at drying conditions of $60{\sim}50^{\circ}C$. The sun drying condition showed the lowest color difference value when compared with far-infrared and hot-air drying. Conclusion: The far-infrared drying showed a faster drying rate, higher saponin content, lower color difference value, and a decrease in energy consumption than seen in hot-air drying.

Drying Experiments Using a Lab-scale Vacuum Drying Apparatus

Kyoung-Sik Bang,Seung-Hwan Yu,Kyung-Wook Shin,Nam-Hee Lee,Gyung-Sun Chae 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

There is a need to develop a quantitative residual water measurement method to reduce the measurement uncertainty of the amount of residual water inside the canister after the end of vacuum drying. Therefore, a lab-scale vacuum drying apparatus was fabricated and its characteristics were evaluated by performing vacuum drying experiments based on the amount of residual water, vacuum drying experiments based on the surface area of residual water, and vacuum drying experiments based on the energy of residual water using the lab-scale vacuum drying apparatus. As a result of the vacuum drying experiments, if the surface area of water is the same, the greater the amount of water, the greater the energy of the water, so more energy is transferred to the surface of the water. Therefore, more water evaporated, and the average temperature of the remaining water was higher. The larger the surface area of the water, the more energy it takes to vaporize it, so the faster it dries and the faster the drying time. Before ice formed, energy was actively transferred by conduction heat transfer from the top, center, and bottom of the water to provide the energy needed for the water to evaporate from the surface. However, no energy was transferred from the water just before it turned into ice. When vacuum drying water, you can dry more water if you dry it slowly over a longer period of time. Therefore, by using a vacuum pump with a low flow rate, the pressure can be lowered slowly to prevent ice from freezing, thereby improving the drying quantity. It was evaluated that there was a good agreement between the energy used when water evaporated and the energy absorbed from the surroundings to within about 4%. Therefore, if the energy absorbed from the surroundings is known, it is possible to evaluate the amount of water evaporated in vacuum drying.

건조방법에 따른 건고추의 품질특성과 생산효율 비교

조명희(Myeoung Hee Jo),신종화(Jong Hwa Shin) (사)한국생물환경조절학회 2018 생물환경조절학회지 Vol.27 No.4

고추는 조미채소의 한 종류로 우리나라 채소시장에서 큰 비중을 차지하는 품목이다. 대부분 고추의 이용은 건고추의 분말형태인 고춧가루로 가공하여 이용되고 있으므로, 고추건조에 대한 품질과 생산성 향상이 중요한 부분이다. 따라서 본 연구에서는 고추의 건조방법에 따라 고춧가루의 품질을 좌우할 수 있는 성분의 변화에 대하여 비교하고, 생산비를 고려하여 적정 건조방법을 제시하고자 실험을 수행하였다. 건조방법으로는 관행으로 많이 이용되는 양건과 화건을 이용하였으며, 제습기를 이용한 제습건조방식을 추가 적용하여 건고추 생산성과 품질을 비교하였다. 고추의 건조방식에 따른 건조율은 화건이 85.1%로 제일 높았고, 이에 따라 고춧가루의 수분함량도 13.5%로 가장 낮게 나타났다. 고추의 색택을 좌우하는 ASTA(American Spice Trade Association) 색도는 양건처리에 비해 화건과 제습건조처리가 높은 결과를 보였다. 고춧가루의 신미성분인 capsaicinoid 함량은 양건처리에 비하여 화건과 제습건조처리에서 모두 낮게 나타나 이에 대한 추가적인 적정 건조조건에 대한 연구가 추가되어야 된다. 당함량은 건조시간이 비교적 짧았던 화건과 제습건조처리에서 양건에 비해 높게 나타났으나 두 처리간에는 유의한 차이를 보이지 않았다. 건고추 생산비용은 제습건조처리가 화건처리에 비해 9.9% 효율이 높은 것으로 나타났다. 본 연구를 통해 화건과 제습건조가 당함량의 증진과 건고추의 색 발현 측면에서는 효과적이었음을 알 수 있었다. 고추의 신미성분인 capsaicinoid 함량 증진을 위해서는 화건과 제습건조처리에서 적정한 건조온도와 건조시간에 대한 연구가 추가되어야 될 것으로 판단되었다. Hot pepper is a kind of seasoning vegetables, which is a major item in the Korean vegetable market. Since the use of hot pepper is processed into pepper powder, which is a powder form of dried hot pepper, improvement of quality and productivity of dried hot pepper is important. Therefore, this experiment was conducted to suggest proper drying method by comparing the changes of hot pepper powder ingredients considering production cost according to the drying method. As a drying method, we used sun drying and heat drying which are widely used in practice. We also compared the productivity and quality of dried hot pepper by applying a dehumidifying drying method using a dehumidifier. Drying rate of hot pepper was highest of 85.1% at heat drying. Accordingly moisture content of hot pepper powder was lowest of 13.5% at heat drying. The American Spice Trade Association (ASTA) color value, which influenced the coloring of red pepper, showed higher in heat drying and dehumidified drying treatment than the sun drying treatment. The content of capsaicinoids was higher at sun drying treatment than that of at both heat drying and dehumidified drying treatments. The content of sugar was higher at heat drying and dehumidified drying treatment where drying time was relatively short than that of sun drying treatment. Also, there was no significant difference in sugar content between the two treatments. The production cost of dried hot pepper with dehumidified drying was 9.9% more efficient than heat drying. Through this study, it was found that heat and dehumidified drying method were effective in increasing sugar content and coloring of hot pepper powder. In order to improve the capsaicinoid content of red pepper, it is considered that appropriate drying temperature and drying time should be added in the process of heat drying and dehumidified drying.

건조 방법에 따른 건조 문어의 품질특성

배태진 전남대학교 수산과학연구소 2015 수산과학연구소논문집 Vol.23 No.-

This study was performed to investigate the method improving the quality of dried octopus, this study compared artificial drying methods i.e. hot air drying and cold air drying with natural drying method. The drying rates of octopus were in the order of hot air, cold air and natural drying. However, cold-air drying was slower than natural drying at 7℃. As the drying temperature increases the drying rate is accelerated. At cold air drying at 7℃, the force of dehumidification was lower than other drying conditions, which resulted in a lower drying rate. There were little color differences between the drying methods and temperature. Octopus dried by cold air-drying had better mechanical texture and sensory qualities than with other drying methods.

Drying characteristics and quality of red ginseng using far-infrared rays

Xiaofeng Ning,Junsoo Lee,한충수 고려인삼학회 2015 Journal of Ginseng Research Vol.39 No.4

Background: The current typical drying methods for red ginseng are sun drying and hot-air drying. The purpose of this study was to investigate drying characteristics of red ginseng by using far-infrared drying. Methods: The far-infrared drying tests on red ginseng were conducted at two drying stages: (1) high temperature for 24 h drying and (2) low temperature drying until the final moisture content was 13 0.5% (wet basis). The high temperature drying stage included three drying chamber temperature conditions of 60C, 65C, and 70C. The low temperature drying stage was conducted at temperatures of 45C and 50C. Drying characteristics were analyzed based on factors such as drying rate, color changes, energy consumption, and saponin content. The results were compared with those of the hot-air and sun drying methods. Results: The results revealed that increases in drying temperature caused a decrease in drying time and energy consumption for far-infrared drying. The saponin content decreased under all drying conditions after drying, the highest value (11.34 mg/g) was observed at drying conditions of 60w50C. The sun drying condition showed the lowest color difference value when compared with far-infrared and hot-air drying. Conclusion: The far-infrared drying showed a faster drying rate, higher saponin content, lower color difference value, and a decrease in energy consumption than seen in hot-air drying. Copy