Helical stirring system for a plastic conversion vessel

A process for stirring material in a plastic conversion vessel,

• comprising a vessel, said vessel comprising an ingress, an egress, a longitudinal axis, and multiple product gas exhaust vents located at a top of the vessel,
• said process comprising the steps of moving waste material comprising a liquid, or a semi-molten material, or a molten material, or a solid inert residue, or any combination thereof, longitudinally through said plastic conversion vessel, said vessel comprising one or more shafts, independently, having a rotatable conveying device, said rotatable conveying device comprising one or more rakes for moving said waste material, or any combination thereof, through said vessel towards said egress, said semi-molten, and/or said molten material comprising one or more polymers or hydrocarbonaceous compounds, or both;
• one or more scraper blades;
• said scraper blades operatively, and independently attached to the one or more brackets and able to slide a radial distance inward and outward in relation to the one or more brackets so that they can scrape the bottom of said vessel upon rotation of said conveying device;
• and
• wherein the one or more shafts are located below the longitudinal axis of the vessel such that a headspace for gases is present above the one or more rakes and the one or more scraper blades whereby the gases can exit the vessel through the exhaust gas vents.

A plastic conversion vessel, comprising:

• said vessel having an ingress, an egress, and an interior wall;
• at least two shafts, each having a rotatable conveying device for moving waste material or a solid inert residue, or both, longitudinally through said vessel towards said egress;
• at least one support housing in said vessel, said support housing located between said rotatable conveying devices, said support housing having arms that are fixed to said vessel interior wall;
• and
• said conveying device having one or more auxiliary scraper blades that are retractable so that they are capable of sweeping under said support housing and moving said waste material therethrough.