STUDIES ON THE EFFICIENCY ASSESSMENT OF E QUIPMENTS FOR THE FORMATIONAND DECOMPOSITION OF OZONE IN THE CLOSED ROOM - TESTS USING 3 TYPES OF EQUIPMENTS

The efficiency of commercially available equipments for ozonization by ultraviolet rays in the rooms was measured and assessed. The volume o f the room was enlarged to 4.5 m(3) and to 54 m(3), and then, the test s were held using three types of ozonization equipments. By considerin g the data including the results of the tests in the small room, the f ormulas and the line graphs on the relationships between the room volu me and the ozone concentration of the steady state, and those between the ozone concentration of the steady state and the input current of a lamp were obtained. As the result of this experiment, a new phenomeno n was found out, that is, the apparent velocity of ozone photo-decompo sition by an ultraviolet ray lamp having a constant initial current wa s slower than that of the spontaneous decompositions, when the room vo lume was enlarged beyond a certain degree. This phenomenon was named a n inversion volume. The overall assessments of these three kinds of eq uipments were as follows: 1) In the case of the ozone formation those equipments are useful, because they are efficient enough to obtain the ozone concentration of the steady state within an hour, though the ti me consumed to achieve it varies according to its room volume. 2) In t he case of the ozone decomposition in the ordinary laboratory, as far as the decomposition velocity is concerned, setting up one ultraviolet ray lamp and one ozone lamp can be less effective than those of the s pontaneous decomposition. Therefore, to increase the decomposition vel ocity, it is necessary to increase the input current of one ultraviole t ray lamp, or to set up the lamps in parallel. 3) In the extremely cl ean room, such as a bioclean room, the ozone decomposition by ultravio let ray (using 140W big type of double wall) is thought to be useful. Lastly, the efficiency assessments and the comparisons of all the equi pments (including the following system) measured in the past was condu cted, and therefore, the one in which the greatest improvement could b e made was found.