CN211946882U - PET waste recovery device - Google Patents

Abstract

The utility model discloses a PET waste recovery device, a serial communication port, include the prepolymerization reation kettle with ethylene glycol, terephthalic acid prepolymerization and the final reaction cauldron that gathers of end, extrude into the screw extruder of melt state waste material PET, will the waste material PET of melt state adds and gathers the filterable melt filter before the reaction cauldron in end, will waste material PET carries out dry drying tower before screw extruder extrudes, will waste material PET is used for the heat preservation feed bin in storage storehouse before extruding behind the drying tower drying. The utility model discloses directly drop into the PET waste material and gather in the reaction kettle eventually, need not carry out degradation treatment to waste material PET in advance, can also avoid the side reaction that the in-process of earlier stage waste material PET degradation produced, improved the utilization ratio of raw materials, further reach the energy saving, increase enterprise economic benefits's purpose.

Description

PET waste recovery device

Technical Field

The utility model relates to a waste recovery device, concretely relates to PET waste recovery device.

Background

Polyester (PET) belongs to a high molecular polymer, and is a polymer produced by condensation Polymerization of Terephthalic Acid (PTA) and Ethylene Glycol (EG) as raw materials. PET plastics have the characteristics of high transparency, impact resistance, difficult fragmentation and the like, are widely applied to the fields of food packaging, electronic and electric appliances, medical health, buildings, automobiles and the like, along with the wide utilization of PET materials, various PET packaging materials are discarded in large quantity, more and more waste PET materials are used, and the ecological environment is seriously polluted because the PET materials are difficult to naturally degrade, so that the recycling technology of PET is widely concerned under the condition.

The PET recovery technology comprises physical recovery and chemical recovery. The physical recycling method is also called mechanical recycling, and mainly recycles the cleaned PET waste materials to prepare end products. The physical recovery method is characterized by simple process flow, easy equipment operation and low investment cost. However, the process has strict requirements on raw materials, separation and purification operations, which otherwise affect the quality of the final product. The chemical recovery method is that PET macromolecules are firstly subjected to degradation reaction under the action of high temperature and high pressure or chemical reagents to form monomers and low molecular weight products. And the generated low molecular weight product is used as a monomer for producing polyester or a raw material for synthesizing other chemical products to prepare a PET polymer, so that the aim of recycling resources is fulfilled.

In the traditional method, a widely-applied PET chemical recovery system is to use a special device to alcoholyze the waste PET raw material into a polyethylene terephthalate (BHET) monomer and then to polymerize again to obtain a product with the quality equivalent to that of the primary polyester, but the method has relatively complex operation. For example, after waste PET raw materials and micromolecular ethylene glycol are added into a double-screw extruder together for alcoholysis, degradation products are collected and then are used to be thrown into a PET polymerization kettle again for participating in the polymerization process, some side reactions are inevitably generated in the process, and the quality of the finally produced polyester product is influenced if the control is not good.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a need not carry out degradation treatment and retrieve the simple PET waste recovery device of flow to the PET waste material in advance is provided.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a PET waste recovery device is characterized by comprising a prepolymerization reaction kettle and a final polymerization reaction kettle, wherein the prepolymerization reaction kettle is used for prepolymerization of ethylene glycol and terephthalic acid, the final polymerization reaction kettle is used for final polymerization, a screw extruder is used for extruding waste PET into a melt state, a melt filter is used for filtering the melt state waste PET before the melt state waste PET is added into the final polymerization reaction kettle, a drying tower is used for drying the waste PET before the waste PET is extruded by the screw extruder, a heat-preservation bin is used for storing the waste PET after the waste PET is dried by the drying tower and before the waste PET is extruded, a predryer is used for predrying the waste PET before the waste PET is dried by the drying tower, the waste PET is added into a discharging bin of the predryer, and the waste PET is cleaned, crushed and screened before being added; and waste PET is extruded from the screw extruder and then added into the final polymerization reaction kettle containing ethylene glycol and terephthalic acid to be jointly finally polymerized to generate new PET.

In order to facilitate the removal of impurities and moisture in the waste PET, the hot drying air can be recycled, and preferably, the pre-dryer is connected with a cyclone separator for removing dust in the hot drying air.

Compared with the prior art, the utility model has the advantages of: the PET waste is formed into a melt state through a screw extruder, and then is directly added into a final polymerization reaction kettle to be finally polymerized together with ethylene glycol and terephthalic acid in the final polymerization reaction kettle to generate new PET, and the whole waste recovery process is simple and easy to operate; directly drop into final polymerization reation kettle with the PET waste material, need not carry out degradation treatment to waste material PET in advance, can also avoid the side reaction that the in-process of preceding stage waste material PET degradation produced, improved the utilization ratio of raw materials, further reach the energy saving, increase enterprise economic benefits's purpose.

Drawings

Fig. 1 is a schematic diagram of an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

The PET waste recovery device in the embodiment comprises a prepolymerization reaction kettle 1 for prepolymerization of ethylene glycol and terephthalic acid, a final polymerization reaction kettle 2 for final polymerization, and a screw extruder 3 for extruding the waste PET into a melt state; the device comprises a melt filter 4 for filtering waste PET in a melt state before being added into a final polymerization reaction kettle 2, a drying tower 5 for drying the waste PET before being extruded by a screw extruder 3, a heat-insulating bin 6 for storing the waste PET before being extruded after being dried by the drying tower 5, a pre-dryer 7 for pre-drying the waste PET before being dried by the drying tower 5, a cyclone separator 10 for removing dust in dry hot air connected with the pre-dryer 7, a blanking bin 8 for blanking the waste PET before being extruded by the screw extruder 3, and a granulator 9 for granulating the final polymerization into new PET.

The working principle is as follows: the waste PET is cleaned, crushed and screened before being added into the blanking bin 8; then the mixture is added into a pre-dryer 7 through a discharging bin 8 for pre-drying; impurities and moisture in the waste PET are removed in the pre-dryer 7 by utilizing dry hot air, dust in the dry hot air is removed by a cyclone separator connected with the pre-dryer 7, and the dry hot air is recycled; after pre-drying, further drying and dewatering in a drying tower 5; after drying, storing the dried mixture in a heat insulation bin 6 for standby; adding the waste PET in the heat-insulation bin 6 into the screw extruder 3 and extruding the waste PET into a melt state; filtering the waste PET in a melt state in a melt filter 4, adding the filtered waste PET into a final polymerization reaction kettle 2 containing ethylene glycol and terephthalic acid, and performing final polymerization to generate new PET; the new PET is then cut into pellets by a pelletizer 9 for subsequent processing.

Claims (2)

1. The PET waste recovery device is characterized by comprising a prepolymerization reaction kettle (1) and a final polymerization reaction kettle (2) for prepolymerization of ethylene glycol and terephthalic acid, a screw extruder (3) for extruding waste PET into a melt state, a melt filter (4) for filtering the melt state waste PET before the melt state waste PET is added into the final polymerization reaction kettle (2), a drying tower (5) for drying the waste PET before the extrusion of the screw extruder (3), a heat-insulating bin (6) for storing the waste PET before the extrusion of the waste PET after the drying tower (5) is dried, a predryer (7) for predrying the waste PET before the drying tower (5) is dried, a lower bin (8) for adding the waste PET into the predryer (7), and cleaning, crushing and screening the waste PET before the waste PET is added into the lower bin (8); waste PET is extruded from the screw extruder (3) and then added into the final polymerization reaction kettle (2) containing ethylene glycol and terephthalic acid to be jointly finally polymerized to generate new PET.

2. The PET waste recycling device according to claim 1, characterized in that a cyclone (10) for removing dust from the drying hot air is connected to the pre-dryer (7).

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