• 설비공학논문집
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• 제27권12호
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• pp.626-632
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• 2015

The purpose of this paper is to analyze the indoor temperature and humidity changes with the operation of a condense drying humidifier. This paper illustrates the principles and composition of a condense drying dehumidifier, which is broadly used in Korean households. Experiments were conducted repeatedly on rainy days in a test chamber. The results showed that the indoor RH was lowered to 40% within 2 hours while the indoor temperature was increased by approximately $4.3^{\circ}C$ with the operation of the humidifier.

• Journal of Biosystems Engineering
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• 제13권4호
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• pp.46-55
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• 1988

The objective of this study was to develop a computer measurement and control system which enable it possible to manage the natural air rough rice drying and storage properly and safely. The following contents of work were taken in this study in order to fulfill the above goal: 1) Design and construction of measurement system which can measure the rough rice drying conditions automatically and transfer them to computer system for data processing. 2) Development of a management software which can determine the need of fan operation by the analysis of drying and/or storage conditions. 3) Design and construction of a control system which deliver the computer decision of fan operation and make it on and off. 4) Technical and economical analysis of the computer measurement and control system development by the comparison experiments of the computer management and of the manual.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2003년도 추계학술발표논문집
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• pp.272-290
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• 2003

In this study a model for the drying process in paper production plants was developed based on the mass and heat balances around drying cycles. Relationships for the heat transfer coefficients between the web and the air as well as between the drying cylinder and the web were extracted from the closed-loop plant operation data. It was found that the heat transfer coefficients could be represented effectively in terms of moisture content, basis weight and reel velocity. The effectiveness of the proposed model was illustrated through numerical simulations. From the comparison with the operation data, the proposed model represents the paper plant being considered with sufficient accuracy.

• Journal of Biosystems Engineering
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• 제19권2호
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• pp.112-123
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• 1994

At present, no appropriate drying conditions can be found for the heated-air drying of mushroom in Korea. Usually, mushroom is being dried at the temperature range of 40 to $50^{\circ}C$ until the moisture content reaches 10~13% (wb). However, drying characteristics of the mushroom should be investigated for quality improvement and efficient drying operation of the mushroom. The results of this study may be summarized as follows ; 1. The effect of air temperature on the rate of drying was greater than that of relative humidity for drying of mushroom, and the rate of drying was increased with increase in the air temperature. 2. Drying rate for Shiitake mushroom showed falling-rate period of drying without constant-rate period of drying. Drying rate for Oyster mushroom showed a short constant-rate period at the initial stage of drying process, and followed by falling-rate period of drying. 3. Exponential and App.-Diffusion models were found to describe well the drying process of Shiitake mushroom. Exponential and Thompson models for Oyster mushroom in which Thompson model was the most suitable for Oyster mushroom. 4. The equilibrium moisture content of the mushroom decreased with decrease in the air temperature and increase in the relative humidity. In room condition($20^{\circ}C$, 54% RH), the calculated values of the equilibrium moisture content showed 11.17% for Shiitake mushroom and 13.19% for Oyster mushroom, respectively.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.19-29
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• 2006

Drying is the least developed of all unit operations of paper and board manufacture. While groundbreaking developments were Introduced during the several past decades in forming, pressing and calendering, no radical changes occurred in drying. The cylinder-drying technology is now more than 200 years old and, while it was subject to many incremental improvements, many of its inherent problems persist. We believe that conventional drying is now approaching the end of its life and the industry is ready for a major breakthrough in drying. Indeed several innovative technologies already exist at various stages of development or commercialization. In general, the novel drying technologies are striving to increase the drying rate, improve the product quality and boost the energy efficiency of drying. A novel, drying method, $Papridry^{TM}$, which combines conductive and convective heat transfer to obtain very high drying rates, is at an advanced stage of development at Paprican. The results obtained when drying printing paper ana board on a self-standing pilot $Papridry^{TM}$ machine and on the pilot paper machine equipped with a tandem of two $Papridry^{TM}$ units demonstrate both, the high drying rate and improved product quality achieved by using this drying method. A mathematical model of this operation has been developed and the software compiled with this model was used to calculate the effect of installing a $Papridry^{TM}$ unit into an existing dryer section. The model also allows to calculate the z-direction distribution of moisture and temperature at various points of the dryer section.

• 플랜트 저널
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• 제5권4호
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• pp.73-79
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• 2009

Increase of consumption in limited coal reserves leads prices surging. As a result, iron works which produce products with coal are in difficulties. Accordingly, it is required a lot of research of using non-caking coal that is relatively low cost and has abundant reserves. Direct drying and indirect drying are two major methods of drying the coal. Recently, to minimize the needed calories and to save energy, using fluidbed or fluidizing method is a recent main trend of minimizing the size of the facility and maximizing energy efficiency. However there is also disadvantage such as increasing facility investment because of installing additional facilities in the latter part. In this study, we will have theoretical researches on the indirect drying method with heat exchange system which have been traditionally used. As a result it is expected to increase the efficiency of the facility operation.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.912-921
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• 1993

A small scale solar greenhouse tray dryer suitable for one or few farmer households is designed in place of sunny ground to dry various agricultural products. The tests on the drying of paddy, groundnut and radish slices by this drying unit have been made. The results indicated that this drying unit had a good heat collecting property, a low heat consumption (4518.7-5676.1 KJ per kg water removal) , a high heat utilizing efficiency (43.75%-54,25%) , a low operation cost (0.057 kwh-0.078 kwh per kg water removal) and good drying quality.

• 한국세라믹학회지
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• 제41권5호
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• pp.353-358
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• 2004

Spray drying is a unique drying process for powder production. Spray dried product must be free-flowing in order to fill the pressing dies rapidly, especially in the ceramic production. The important powder characteristics are; the particle size distribu-tion and moisture content of the finished product that can be estimated and adjusted by the spray dryer operation, within limits, through regulation of atomizer and drying conditions. In order to estimate the moisture content of the resultant dried product, we modeled the control system of the drying process using two different Artificial Neural Network (ANN) approaches, namely the Back-Propagation Multiplayer Perceptron (BPMLP) algorithm and the Radial Basis Function (RBF) network. It was found out that the performance of both of the artificial neural network models were quite significant and the total testing error for the 100 data was 0.8 and 0.7 for the BPMLP algorithm and the RBF network respectively.

• 한국식품저장유통학회지
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• 제1권2호
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• pp.99-105
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• 1994

To convert the analog signal from the drying process into the digital signal, the interface circuit was designed and built. To measure the weight and temperature during drying process, strain gauge type load cell and temperature transducer composed of pt 100 $\Omega$ thermometers and wheatstone bridge circuits were built and used. The temperature control device was composed of photocoupler and triac. Microcomputer aided experimental convective drying system was built with above cricuits and devices. Drying characteristics of onions can be estimated using this system.

• 펄프종이기술
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• 제38권4호
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• pp.17-23
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• 2006

Paper has fibers and fines network structure and it is strongly affected by interface bond-ing between fibers. Paper structural properties can be determined depending on the inter-fiber bonding. Fines play an important role in Campbell and consolidation effect through wet pressing and drying operations. The fines are essential for the formation of bonds between fibers and for the improvement of strength properties of papers. Since the fines are components of the pulp, there are always two factors to be considered: the quality and quantity of the fines. The quality of fines might be a potential variable to give a more accurate picture of the papermaking potential of the pulp. The object of this study is to investigate the effect of different types of pulp fines on the properties of paper and to access the potential of fines for controlling the bulk of paper. Refined Sw-BKP, Hw-BKP and BCTMP fines were used to investigate the fines effect. Wet-web strength, breaking length, scattering coefficient, and hydrodynamic specific volume, and drying shrinkage were measured. According to the results, chemical and morphological compositions of fines do not strongly affect to wet-web forming by their similar Campbell effect, but strongly affect to drying operation which forms hydrogen bonding among fiber-fines-fiber matrixes. Paper bulk should be controlled by the extent of hydrogen bonding between fibers during drying operation.