| 摘要 |
<p>The biological filter consists of a filter housing to receive water and or nourishing fluid, containing one or more filter elements serving to receive plant root balls and culture heads containing air and root passages with plant filter ballast. It can be used with or without living plants. It has means to condense tobacco smoke an tar from air in the immediate vicinity of the filter. there are also devices for air heating and labyrinth medium cooling of the said condenser.</p> |
