試験用実大展示ケースを用いたケース内のガス清浄化と濃度予測

摘要

One problem in the museum environment is air pollutants in airtight display cases' some of which cause adverse effects on artifacts inside. Their gases, especially acetic acid gas, are mainly emitted from interior materials used in display cases. There are two systems for reducing the level of pollutants inside the enclosure. One is an active adsorption filter fan system and the other is a ventilation fan system that takes the clean air from the exhibition room. The present paper reports on the test using these systems to control acetic acid gas pollutants in a display case. Several measurements were conducted to see air distribution, air exchange rate and acetic acid gas concentration in a display case. The display case used in the experiments was made for environment test. Performance of active adsorption air filter within enclosures and ventilation effect by the fan were also measured. As a result it was found that acetic acid gas concentration in the display case decreased to 30% by using an adsorption filter fan system and it became of equal level to that in an exhibition room by using a ventilation system. Effects of control of pollutants by each system were evaluated by using ventilation volume with clean air (i.e. equivalent ventilation volume). Changes of gas concentration in the display case were estimated through prediction formula using factors of equivalent ventilation amount and operating period of the fan. From the results it was estimated that good air environment in the display case was maintained by operating an adsorption filter fan system for about two hours a day.%美術館•博物館においては，展示品の多くは，気密性の高い展示ケース内で展示される。そのため，ケース内の空気質は内装材からの放散ガスで高濃度な環境にさらされる危険性が高い。この対策として，新しく展示ケースを製作する際には内装材はガス放散の少ないものを用い，さらに展示するまでの間にガスの放散を促進する枯らしをおこない，放散量の低減をはかる。また，展示が始まってからの対策では，遮蔽材や吸着剤を設置し，あるいはケースを開放し空気を入れ替えるなどして清浄化をおこなうが，その効果は必ずしも十分とはいえない。筆者らは，試験用実大展示ケースを製作し展示ケースの清浄化方法の研究について取り組んでおり，既報では，展示ケース内のガス濃度推移について解析した。本報では，ファンを用いて吸着フィルタと換気による清浄化実験をおこない，その効果を評価し，展示ケース内の長期間にわたるガス濃度推移を予測した。