摘要 |
<p>The wall has a first wall part (1) provided with an inlet (3) and arranged on a source. A second wall part (2) is connected to the first wall part. The first wall part communicates with the second wall part through a first pressure relief valve (5). The second wall part is provided with an external exhaust valve (6). A third wall part is connected to the second wall part by a second pressure relief valve (8) for transfer of air contained in the first wall part. The first, second and third wall parts are longitudinally divided into two compartments.</p> |