| 摘要 |
<p>The safety hole is placed between equipments for forming a gaseous product preventive siphon. The safety hole comprises a vat, a cover closing the vat and being centrally provided with a vertical partition wall having a bottom portion placed at a determined height from bottom of the vat. The vat is filled with a neutral liquid at a level substantially higher than the bottom portion of the vertical partition wall thus forming an aqueous compartment and a downstream compartment.</p> |
