| 摘要 |
<p>Filter has perforated to form a bed for use with aspirators (or dust masks). The plates are mounted in a housing with an inlet and an outlet branch of the face mask. It has square or rectangular cross section and a vertical partition down the centre which divides it into two chambers. Each plate is formed from a pair of perforated plates between which is a mat of cotton, viscose or similar. This is held in position by a spring loaded retaining clip. The plates are held against seal in the vessel wall and in the central partition. For use by persons working in dusty environment to prevent damage to health, esp. from very fine dusts. It provides a filter, the medium in which can be easily removed as opposed to conventional filteres where the whole unit is thrown away and replaced.</p> |
