Process for melting plastic for subsequent feeding to a processor via a melt pump
AssigneeExxonMobil Chemical Patents Inc.
InventorJay L. Reimers
Life of this patent
Estimating the term…
Abstract
Process for feeding plastic material, e.g. a plastic waste, to a processor such as a thermochemical reactor, e.g. a pyrolysis reactor. The process comprises an optional shredder or disintegrator (1), a conveying system (2), a feed hopper (3) with a lock hopper or rotary valve, a melting tank (6) with an agitator (5) followed by a melt pump (7) for the delivery of molten plastic to the processor. The advantage of the current process includes the ability to supply a consistent, metered flow to the processor, independent of the recycled plastic's melt properties, or the form or particle size and distribution of the plastic material.
Claims24
A process comprising:
- conveying a quantity of plastic material into a feed hopper via a screw conveyor or an air conveyor;
- supplying a controlled amount of the plastic material directly into a melting tank from the feed hopper using a rotary valve control mechanism, wherein the rotary valve control mechanism forms a gas seal between the feed hopper and the melting tank, wherein the rotary valve provides a seal against a backflow of a gas from the melting tank, and wherein the rotary valve controls the quantity of the plastic material supplied into the melting tank;
- melting the plastic material in the melting tank at a temperature from 200° C. to 300° C. while agitating the plastic material using a melting tank agitator to form a molten plastic material and a gas mixture;
- supplying the gas mixture to a condenser, wherein the gas mixture is contacted by a recirculated liquid in the condenser that strips out acid gases and other water-soluble gases, and wherein other gases not stripped out are compressed and at least partially sent back to the melting tank;
- withdrawing the molten plastic material using a melt pump fluidically connected to the melt tank;
- and
- supplying the molten plastic material into a processor in a controlled metered flow using the melt pump.
A process comprising:
- conveying a quantity of plastic material into a feed hopper via a screw conveyor or an air conveyor;
- supplying in a continuous manner a controlled amount of the plastic material into a melting tank from the feed hopper using a rotary valve control mechanism, wherein the rotary valve control mechanism forms a gas seal between the feed hopper and the melting tank, wherein the rotary valve provides a seal against a backflow of a gas from the melting tank, and wherein the rotary valve controls the quantity of the plastic material supplied into the melting tank;
- melting the plastic material in the melting tank at a temperature from about 200° C. to about 300° C. while agitating the plastic material using a melting tank agitator to form a molten plastic material and a gas mixture,
- supplying the gas mixture to a condenser, wherein the gas mixture is contacted by a recirculated liquid in the condenser that strips out acid gases and other water-soluble gases, and wherein other gases not stripped out are compressed and at least partially sent back to the melting tank;
- withdrawing the molten plastic material using a melt pump fluidically connected to the melt tank, wherein the molten plastic material has a melt viscosity in between 1000 cP and 20 MM cP;
- and
- supplying the molten plastic material into a processor in a controlled metered flow using the melt pump.
Dependencies are inferred from the claim text.