| 摘要 |
A fractionating apparatus for separating fine fibers from coarse fibers in water containing a certain amount of air. A spray nozzle is arranged in a vessel and directed towards a screening cloth incorporated as a part of the vessel walls and which, on its discharge side, is arranged for free runoff of the fine particles and the part of the liquid passing through the seal means to its discharge side, while coarse particles and the other part of the liquid is bounced off the inner side of the screening cloth and collected in the vessel to a predetermined liquid level maintained by allowing the liquid to depart through an outlet. A desired pressure difference is maintained across the sieve means. The vessel is closed with the exception of the places where the sieve means are situated and where the outlet is arranged. The outlet side of the sieve means is exposed to atmospheric pressure while its inlet side is acted on by the excess pressure prevailing, during operation, in the air space between the liquid surface in the vessel and the sieve means. The excess pressure is provided by the air released from the liquid when it is sprayed from the nozzle. The outlet from the vessel is situated at the lower portion of the vessel and is in communication via a passage with an overflow situated outside the vessel, said overflow being raisable and lowerable for regulating the excess pressure in the vessel. |
