摘要 |
<p>A device for pre-processing a synthetic thermoplastic material, such as polyester waste, comprises at least two containers (1, 13) connected in series, in each of which a comminuting and mixing tool (5) rotates at the base of the containers (1, 13) about a vertical axis. At least the downstream container has an evacuation duct (18) which can also be used to introduce an inert gas if required. The containers (1, 13) are connected by a sleeve (12) in which there is a stop valve (20) to facilitate trouble free maintenance of the vacuum in the downstream container (13) until the valve (20) is opened, thus allowing the vacuum in the container (13) to draw in the material in the upstream container (1). In the upstream container (1) (as seen in the flow-direction of the material), the material is pre-comminuted, pre-heated, pre-dried and pre-compacted and that process is enhanced by the turbulence in the material as it is sucked into the downstream container (13). Completely homogenous material is thus transported for further processing by a worm (16) which is connected to the last container (13).</p> |