• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2211-2216
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• 2007

Liquefied gas vaporizer means machine to vaporize the liquefied gas as liquid nitrogen($LN_2$), liquefied natural gas(LNG), liquid oxygen($LO_2$) etc. In the air type vaporizer, the frozen dew is also created by temperature drop (below 273 K) on vaporizer surface. This problem increases as the time progresses and humidity increases. In addition, the frozen dew gradually becomes frost deposit consequently, heat transfer through vaporizer decreases because frost deposit form adiabatic sheet. Because of this reason, recent vaporizer system is installed as parallel type, this vaporizer system needs more expensive installation costs and more space. This paper was investigated on the heat transfer characteristics of liquefied gas vaporizer with super low temperature and this paper was carried out the numerical about air heating vaporizer with super low temperature. The numerical analysis on the heat transfer was studied on the effect of geometric parameters of the vaporizer, which are length 1000 mm of 4fin75le type vaporizer. 4fin75le means number of fin is 4 and height of fin is 75 mm.

• 동아시아식생활학회지
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• 제2권1호
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• pp.57-68
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• 1992

In order to obtain the information on the status of using university cafeteria and students' preferences, the survey was conducted through questionaires to 434 students(male:195, female : 239) of 8 universities - 2 universities employed dietitian and 6 universities which didn't employ dietitian -through all the area of Incheon from 19th November 1990 to 14th December, 1990. The results obtained were as follows. 1) For keeping temperature of meals until service to students Refrigerator or warming cabinet or putting meals on low flames were used, and the amount for one person was almost decided by rough estimation by experience. All the foods remained were discarded. Also most of the cooking manager's age were from 50 to 59 and almost cooking managers graduated middle school. The fuel to cook was gas or kerosene. Method to disinfect tableware was boiling. 2) In case of the frequency of using university cafeteria, male students used cafeteria more often than female students, and regardless of sex students made use of cafeteria for lunch more than for breakfast and supper. Students also used university cafeteria not employing dietitian more than cafeteria employing dietitian. Disregarding of male, female, cafeteria employing cafeteria not employing dietitian, all students pointed out that main reason for using cafeteria were 'low price' and 'no other place to eat' And minor reasons were ' good taste' and 'meal quality'. On the contrary, the case of not using cafeteria were 'waiting in line' to male students, 'poor taste' to female students, 'waiting in line' and 'no varieties' on the cafeteria which employed dietitian, 'poor taste' and 'poor hygienes' on the cafeteria which didn't employ dietitian. 3) Considering of the preferences of menu, both male and female students liked "Bibim Bab" And male students prefered meals which contained broth both but female students prefered a light meals. 4) the difference of preferences showed that female student's preferences were high at all foods, and the preferences of fruits were high for both students. In detail, male students liked port, liver and small intestine of cattle, oyster and beans boiled in soysauce. But female students likde milk, yogurt and cucumber.