| 摘要 |
An assembly has a housing with a collection chamber (50) with an inlet annula into the forward end and a discharge cannula from the rearward end, the latter having a valve to control discharge into evacuated containers. A fluid bleed passage (51) is formed between housing forward and rearward ends and has a vent to ambient. - Material (125) in the bleed passage is responsive to aqueous material passing through to swell and close the passage, so that as the chamber is filled through the inlet cannula any gas is forced through the bleed passage and vent until the liquid enters the passage. The material is pref. of hydrolysed starch-polyacrylonitrile graft copolymer with side chains contg. carboxamide and carboxylate gps. |
