| 摘要 |
This invention concerns an arrangement for separating plastics and other materials of different densities in a liquid bath by flotation. The batches of plastics fed to the flotation baths often also contain ferrous metals and non-ferrous metals and other materials which are heavier than plastics. Sin ce these materials in the batch which is to be separated are heavier than pl astics, they settle quickly on the perforated base (1) while the plastics pa rticles are still floating in the flotation bath. The still-floating plastic s particles are transferred to a second stage and separated there in accorda nce with their different densities. The heavier materials, which settle from the batch in the first stage, easily result in the through-openings for liq uid in the perforated base (1) closing. For this reason, it is the problem o f this invention to remove these materials, usually settling on the perforat ed base in pile form, again without causing the liquid settled in the settli ng tank (27) to move in an undesirable manner, and thus to prevent already s ettled materials from rising up and mixing again with still-floating plastic s particles. The invention proposes to mount the perforated base (1) in a mo vable manner, to leave a gap between the perforated-base boundary and the wa ll of the settling tank and to displace the perforated base (1) at intervals slowly in a direction which reduces the size of the gap and quickly and abr uptly in the opposite direction: as a result of the abrupt movement of the p erforated base (1), the kinetic energy stored in the piles of metal or the o ther heavy materials moves these materials in the direction of the gap perip hery (S) and conveys them through the gap (7) into the settling chamber loca ted beneath the perforated base. These materials can then easily be guided a way from there. |
