• Title/Summary/Keyword: pre-drying

Search Result 151, Processing Time 0.027 seconds

The simulation system for ceramic drying processes (세라믹 건조공정 시뮬레이션 시스템)

  • 금영탁;김준한;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.11 no.3
    • /
    • pp.120-126
    • /
    • 2001
  • The simulation system for analyzing the ceramic drying process is developed. This system consists of 3 parts: pre-processor, analyzer, and post-processor. The pre-processor creates 3-dimensional ceramics, makes finite-element models, and prepares analyzers input. The analyzer computes temperature, moisture, residual stress, displacement, etc. during the drying process using the information about finite-element model, material property, and boundary condition provided by the pre-processor. In post-processor, the analyzers results are visualized to help designers evaluation of the drying of the ceramic.

  • PDF

Study on the Change of Relative Humidity in Subsea Pipeline According to Drying Method (건조 공법에 따른 해저 파이프라인 내부 상대습도 변화 특성 연구)

  • Yang, Seung Ho
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.2
    • /
    • pp.406-413
    • /
    • 2022
  • The subsea pipeline pre-commissioning stage consists of the following processes: Flooding, Venting, Hydrotesting, Dewatering, Drying, and N2 Purging. Among these processes, drying and nitrogen purging processes are stipulated to reduce and maintain the relative humidity below dew point to prevent the generation of hydrate and the risk of gas explosion in the pipeline during operation. The purpose of this study is to develop an analysis method for the air drying and nitrogen purging process during pre-commissioning of the subsea pipeline, and to evaluate the applicability of the analysis method through comparison with on-site measurement results. An analysis method using Computational Fluid Dynamics (CFD) was introduced and applied as a method for evaluating the relative humidity inside a subsea pipeline, and it was confirmed that analysis results were in good agreement with the on-site measurement results for the air drying and nitrogen purging process of the offshore pipeline. If the developed air drying and nitrogen purging analysis method are used as pre-engineering tools for pre-commissioning of subsea pipelines in the future, it is expected to have a significant impact on the improvement of work productivity.

Effect of Pre-treatment Methods on the Quality of Ginger during Storage (전처리 방법이 생강의 저장 중 품질에 미치는 영향)

  • 정태연;정태연;남궁배;이세은
    • Food Science and Preservation
    • /
    • v.6 no.1
    • /
    • pp.1-6
    • /
    • 1999
  • Fresh gingers, harvested in Seosan, Choongcheongnam-do, were pre-treated by a washing-pasteurizing-drying process, a curing process, and non-treated, respectively. Then they were stored in a lab-scale storage room(12$^{\circ}C$, >92%RH) to investigate the effect of pre-treatment methods on the quality changes during long-term storage. Weight loss of ginger during storage showed ranges in 0.7∼4.3%, and the weight of gingers pre-treated by washing-drying process showed a tendency to change less than those treated by curing. After storage of 130 days, spoilage rates were about 20% in non-treated, 11% in curing treated, and 12% in washing-drying treated ginger,, showing the effect of pre-treatment. The final rate of sprouting was 13∼15% regardless of treatment methods. The firmness of gingers showed a tendency to decrease in stored ginger for the longer period; however, the values were ranged from 1,200 to 1,400 g/$\textrm{cm}^2$, that is hard enough to show a marketable quality. The contents of reducing sugar showed a tendency to increase with the lapse of storage time.

  • PDF

Effect of Reserve Air-Drying of Korean Pine Heavy Timbers on High-temperature and Low-humidity Drying Characteristics (예비천연건조가 잣나무 중목구조부재의 고온저습건조 특성에 미치는 영향)

  • Lee, Chang-Jin;Lee, Nam-Ho;Park, Moon-Jae;Park, Joo-Saeng;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
    • /
    • v.42 no.1
    • /
    • pp.49-57
    • /
    • 2014
  • The pre-air-drying of Korean pine before the high-temperature and low-humidity drying was shown to be effective in uniform moisture content distribution and prevention of surface check. Our results suggest that initial moisture content of the timber also plays important role in high-temperature and low-humidity drying method. The pre-air-drying also helps in the reduction of surface checks in Korean pine when compared to the Korean pine dried by only high-temperature and low-humidity. End-coating was not effective in the prevention of twist, shrinkage, case hardening and internal checks. The pre-air-drying reduces the internal tension stresses which occur during high-temperature and low-humidity drying thus decreasing case hardening and also preventing internal checks. The pre-air-drying decreases the moisture content and causes shrinkage which leads to increased twist in the Korean pine.

Analysis of Microorganisms and Water Transport Properties of the Cotton Fabrics through Dehydration and Drying Process during Washing (세탁의 탈수와 건조과정 중 면직물의 수분전달특성 및 미생물 분석)

  • 최해운;박명자;차옥선
    • The Research Journal of the Costume Culture
    • /
    • v.10 no.5
    • /
    • pp.578-589
    • /
    • 2002
  • The purpose of this research was to analyze the residual water retention and to determine the number and species of microorganisms from the wet cotton fabrics in dehydration and drying process during washing. The drying rates of terrycloth and interlock knit under the rainy seasons were measured according to the dehydration and hanging methods, layers of fabric and pre-treatment agents. Microorganisms were isolated from the dried terrycloth by pure culture, and were identified by Biolog system. The results are as follow: The initial water retention of fabrics after dehydration decreased in the order of dripping>centrifuge>squeezing method, which affected the drying rate. The drying rates were faster by increasing surface area of fabrics. There was no significant difference in drying rate among the fabrics pre-treated with detergent, or fabric softener, or cationic surfactants such as Cetyltrimethylammonium bromide(CTAB) and Benzalkonium chloride(BC). Puedomonas aureginosa was found in the fabrics treated with a powder-type detergent. On the other side, there was no growth of microorganism in the fabrics treated with a liquid-type detergent (containing antibacterial agent), CTAB and BC.

  • PDF

Effect of presurfacing on drying rate and drying defect of Quercus grosseserrata BI. (전평삭처리(前平削處理)가 물참나무의 건조속도(乾燥速度)와 건조결함(乾燥缺陷)에 미치는 영향(影響))

  • Han, Gyu-Seong;Jung, Hee-Suk
    • Journal of the Korean Wood Science and Technology
    • /
    • v.14 no.4
    • /
    • pp.29-39
    • /
    • 1986
  • To investigate the effect of presurfacing, both 25mm rough and pre surfaced oak boards (Quercus grosseserrata BI.) were dried in the same dry kiln condition. Drying curves, drying strains and drying defects of rough and presurfaced boards were compared. The results obatained are as follows. 1. Average drying rate of rough and presurfaced boards from green to 10% M.C. was 0.276%/hr. and 0.284%/hr., respectively. 2. At the early stage of drying, in case of rough boards, maximum tensile strain of outer slices was $-24.2{\times}10^{-4}$mm/mm and maximum compressive strain of innermost slices was $13.0{\times}10^{-4}$mm/mm, and in case of pre surfaced boards, maximum tensile strain of outer slices was $-14.5{\times}10^{-4}$mm/mm and maximum compressive strain of innermost slices was $28.1{\times}10^{-4}$mm/mm. And in both cases, stress reversal occurred at about 40% M.C.. 3. Maximum surface checking appeared at about 40% M.C.. Of the 10 rough boards. 6 hoards contained surface checks, but presurfaced boards did not contained surface checks after drying. And the results of end checking were similar to those of surface checking. But, honeycomb was not found in both cases. 4. Board shrinkage. warp and casehardening of presurfaced boards were similar to those of rough boards. But, collapse of prsurfaced boards was less than that of rough boards.

  • PDF

Effects of Freezing Pretreatment on Juice Expression and Drying Characteristics of Prunus mume Fruit (동결 전처리가 매실의 착즙과 건조 특성에 미치는 영향)

  • Chung, Hun-Sik;Kim, Han-Soo;Lee, Young-Guen;Seong, Jong-Hwan
    • Food Science and Preservation
    • /
    • v.17 no.4
    • /
    • pp.507-512
    • /
    • 2010
  • The effects of pretreatment by freezing on juice expression and drying characteristics of Prunus mume fruit were investigated. Fresh fruit slices were frozen at $-20^{\circ}C$, thawed, and then either pressed (to yield juice) or dried. Fresh fruit slices were used as controls. Both juice yield and drying rate were higher when pre-frozen fruit was tested, compared to fresh fruit. The L and b color values were lower in the juice and dried powder of pre-frozen compared to fresh fruit. The a color value was higher in juice and powder prepared from pre-frozen fruit compared to fresh fruit. There was no significant difference in free sugar or organic acid content between juices and powders from pre-frozen and fresh fruit. None of soluble solid content, titratable acidity, or juice pH was affected by freezing pretreatment. The results suggest that such pretreatment may be useful to increase juice yield and drying rate. However, browning of juice and powder may be elevated.

Effect of Pre-heating Conditions on Extraction Yield of Phelinus linteus Tea (가열 전처리 조건이 상황버섯 차의 추출수율에 미치는 영향)

  • Park, Min-Kyung;Kim, Cherl-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.37 no.5
    • /
    • pp.653-659
    • /
    • 2008
  • In this study, the optimum pre-heating condition was investigated to improve water extraction yield of Phelinus linteus tea. Pre-heating was carried out using drying oven or hot plate at different temperatures and times, and extraction yield was estimated by measuring optical density at 370 nm and soluble solid content. The highest optical density and soluble solid content of Phelinus linteus tea were observed when pre-heated at $70{\sim}80^{\circ}C$ for 30 minutes in drying oven. Pre-heating in drying oven resulted in also faster color changes of Phelinus linteus tea at lower temperature. According to the organoleptic evaluation, pre-heated Phelinus linteus tea in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was preferred compared to the non-treated. In conclusion, pre-heating in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was found to be the most efficient conditions to increase extraction yield of Phelinus linteus tea.

Water Absorption and Dimensional Stability of Heat-treated Fast-growing Hardwoods

  • PRIADI, Trisna;SHOLIHAH, Maratus;KARLINASARI, Lina
    • Journal of the Korean Wood Science and Technology
    • /
    • v.47 no.5
    • /
    • pp.567-578
    • /
    • 2019
  • A common problem with fast-growing hardwoods is dimensional instability that limits use of their wood. In this study, we investigated the effects of pre-drying methods, temperatures, and heating duration on the specific gravity, water absorption, and dimensional stability of three tropical fast-growing hardwoods, jabon (Neolamarckia cadamba Roxb.), sengon (Falcataria moluccana Miq.), and mangium (Acacia mangium Willd.). Wood samples were pre-dried by two methods (fan and oven at $40^{\circ}C$), and heat treatments were performed at three temperatures (120, 150, and $180^{\circ}C$) for two different time periods (2 and 6 hours). The specific gravity, water absorption, dimensional stability, and structural changes of the samples were evaluated. The results revealed that heat treatments slightly reduced the specific gravity of all three wood species. In addition, the heat treatments reduced water absorption and significantly improved dimensional stability of the samples. Oven pre-drying followed by heat treatment at $180^{\circ}C$ for 6 hours resulted in good physical improvement of jabon and sengon wood. Fan pre-drying followed by heat treatment at $180^{\circ}C$ for 2 hours improved the physical properties of mangium wood. The heat treatment shows a promising technique for improving the physical characteristic of fast growing hardwoods.

Method for Drying of Crude Extract Obtained by Biomass Extraction Using an Ionic Liquid (이온성 액체를 이용한 바이오매스 추출에 의해 얻어진 추출물의 건조 방법)

  • Kim, Seul Ki;Kim, Jin-Hyun
    • Korean Chemical Engineering Research
    • /
    • v.54 no.3
    • /
    • pp.374-379
    • /
    • 2016
  • When using an ionic liquid as co-solvent, the extraction efficiency of anticancer agent paclitaxel from biomass was dramatically improved. However, the residual ionic liquid had a significant negative effect on convenient and feasibility of following concentration and drying steps. In this study, a novel method was developed for the effective drying of the crude extract obtained from biomass extraction with ionic liquid. The residual ionic liquid was easily and conveniently removed by drying alone after pre-treatment and additional washing of a sample with water. The optimal crude extract/water ratio and mixing time for pre-treatment and crude extract/water ratio for additional washing were 1:70 (w/v), 4 min, and 1:100 (w/v), respectively. In the microwave-assisted drying process, the drying time was 9-fold shorter than in the vacuum oven drying process.