• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.44-48
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• 2021

Semiconductor inspection equipment makes components using materials with insulating properties for functional inspection including current and voltage of semiconductor parts. A representative insulating material is plastic, and plastic is made of a component through an injection process using plastic pellet. When plastic pellets contain excessive moisture, problems such as performance degradation and product surface defects occur. To prevent this, pre-drying is essential, and the heat convective type is the most applied. However, the heat convective type has a problem of low consumption efficiency and a long drying time. Recently, many studies have been conducted on a drying method using microwaves due to high energy efficiency. In this paper, drying was performed using a microwave for drying PC pellets. Energy consumption and drying efficiency analyzed by set up an experimental apparatus of heat convective, microwave, and hybrid(heat convective + microwave) types. It was confirmed that energy consumption and drying efficiency were high when drying using microwaves, and it was confirmed that the hybrid method improved drying performance compared to the heat convective method. It is expected that the research results of this paper can be used as basic data for drying plastic pellets using microwave.

• Food Science and Preservation
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• v.2 no.1
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• pp.155-161
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• 1995

We examined the drying characteristics and the drying rate model equation of garlic(allium sativum L.) using computer aided convective drying. The drying chanacteristic curve of garlic divided into constant rate drying period and 2 stage of falling rate drying period. The drying rate was fairly affected by hot air temperatures during the total drying period, but air flow rates has nearly no effect on the drying rate except initial drying period. Of the several model equation, r2 values of page model equation was the highest, and the estimated drying profiles were comparatively coincided with the observed drying profiles. Page model equation was suitable to predict the drying rate and moisture content during drying of sliced garlic.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.145-150
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• 2009

In this study, characteristics of microwave and convective drying are studied by using a multiphase porous media model. Temperature and moisture profiles for hot-air convective heating and microwave heating of 1-D porous media with varying time and space are numerically investigated. This result shows the microwave drying method is more effective than the convective drying method. Comparing to convective drying, microwave drying can increase temperature and evaporation rate significantly since microwave generates internal heat and increases internal pressure, which results in moisture movement toward the surface on which moisture is vaporized.

• Journal of Biosystems Engineering
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• v.14 no.4
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• pp.262-271
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• 1989

Red pepper is one of the most important agricultural products in Korea. Generally, raw red pepper is dried after harvest and the dried red pepper is powdered. Washing process is necessary to produce clean powder before powdering process. This study, therefore, was performed to analyze the drying characteristics of the rewetted red pepper and the energy utility during hot-air-convective and infrared-radiant drying. Drying effectiveness, De, was defined for the analysis of energy utility in this study, and its value was determined according to the energy source. Infrared-radiant drying was more favorable than convective drying according to drying effectiveness. But the temperature variation was appeared between the radiant surface and opposite surface of red pepper in infrared-radiant drying.

• Food Science and Preservation
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• v.1 no.2
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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.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.45-51
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• 2004

Combined microwave-convective drying of 2.4mm-thick radiata pine veneer grown in New Zealand was conducted to investigate drying characteristics. The veneers could be dried from 160% to 0% moisture content in 7.5 min by microwave drying combined with hot-air of 100℃. This drying rate is about three times higher than that of conventional convective drying with only hot air of 100℃. However there remained charred spots when too high microwave power was applied. Therefore investigations of the microwave-drying characteristics of veneer of various sizes and species are needed to determine the optimal drying conditions.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.557-566
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• 2019

Radial and tangential water diffusion in Eucalyptus globulus wood was investigated using three mature trees from a forest in Khemis Sahel (North Morocco). Absorption and desorption kinetics experiments were conducted at ambient temperature ($25^{\circ}C$) and $30^{\circ}C$, respectively, and a relative humidity of 60%. The diffusion coefficients in the two directions were determined under imposed hygrothermal conditions; they were greater in the radial direction for the absorption as well as desorption processes. Convective drying under load, preceded by reconditioning and followed up by balancing, revealed the drying conditions that corresponded to the appropriate drying schedules for E. globulus wood. This was verified by measuring the cracks and bowsbefore and after drying of boards.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.519-532
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• 2020

Because lotus root has a short shelf life, the quality easily deteriorates. Thus, the harvested lotus roots are processed into a variety of products. Drying is one of the simplest food preservation methods, which can increase food stability. However, the convective drying method takes a long time and requires high energy consumption. Combination drying methods have emerged to overcome the limitations of the convective drying method. This study investigated the drying characteristics of lotus root and determined the optimal drying model of lotus root depending on the microwave and hot-air combination drying conditions. The lotus root slices (5 mm in thickness and 40 mm in diameter) were dried by different drying conditions that were combined with three microwave power levels (50, 100, and 150 W) and two hot air temperatures (50 and 60℃) at a velocity of 5 m·s^-1. Eight drying models were tested to evaluate the fit to the experimental drying data, and the effective moisture diffusion (D_eff) values of the lotus root slices dried by combination drying were estimated. The combination drying time of the lotus root was significantly reduced with the high air temperature and microwave power. The effective moisture diffusion (D_eff) of lotus root was more affected by the air temperature than microwave power intensity. Logarithmic model was most suitable to describe the drying curve of lotus root in the microwave-hot air combination drying method.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.138-143
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• 2015

This paper was aimed to study the drying kinetics of coffee and to investigate the thin-layer drying kinetics of coffee by using a convective air dryer. The coffee was dried for the temperatures of 40, 50 and $60^{\circ}C$ with relative humidity in the range of 14-25% the airflow rate fixed at 1 m/s. According to the experiment result, the drying rate curve showed that drying process took place only in the falling rate period. Seven thin layer drying models (Newton, Page, Henderson and Pabis, Logarithmic, Wang and Singh, Two terms, Modified Henderson and Pabis) were fitted to the experimental moisture content data. The Two-trem model was found to be a better model for describing the characteristics of coffee for the temperatures of 40, 50 and $60^{\circ}C$. The effective moisture diffusivity of coffee increased when the drying temperature increased. The value was in the range of $4.5028{\times}10^{-11}$ to $6.4803{\times}10^{-11}m^2/s$.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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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.