| 摘要 |
The device essentially comprises a first tubular cylindrical body (1) and a second tubular cylindrical body (2), partially tightly encompassing the first body and coaxially extending therewith, said first body being provided with two upper (7) and lower (7 min ) threaded portions, with the lower threaded portion (7 min ) there being engaged an end portion of the second tubular body (8) in such a way as to define an annular chamber (9) between the two bodies (1, 8), the second body (8) being provided through the wall thereof with two pluralities of radially extending holes (10), with the upper threaded portion (7) there being screw engaged a sleeve (23) provided with a radially extending fitting (26) to be coupled to a small diameter vapor evacuating hose (27), the lower end of the second body being engaged with a further sleeve member (12) to be screw coupled to the threaded mouth of the drum therefrom the acid is to be drawn through the first body. |
