GB2274908A

GB2274908A - Pyrolysing waste

Info

Publication number: GB2274908A
Application number: GB9225168A
Authority: GB
Inventors: Roger Frank Jailler
Original assignee: PYROTECH
Current assignee: PYROTECH
Priority date: 1992-12-02
Filing date: 1992-12-02
Publication date: 1994-08-10
Anticipated expiration: 2012-12-02
Also published as: GB9225168D0; GB2274908B

Abstract

A reaction vessel (12) in which waste vehicle tyres can be subjected to a pyrolytic action includes a convoluted heating element (14), a heat source (16) to supply heat to the heating element and a supply of nitrogen through inlet (20) and outlet (22) to ensure substantial absence of oxygen from the vessel and to carry over volatile gasses from the vessel for further treatment. <IMAGE>

Description

Disposal of Waste Material The present invention relates to the disposal of waste material. In particular the invention relates to the disposal of used or unserviceable vehicle tyres.

It is well known that many millions of vehicles tyres are scrapped each year, either due to wear or unserviceability.

Such tyres contain valuable materials such as oils, carbon black and steel wire which if they can be recovered economically can be recycled for further uses.

Many proposals have been made for apparatus and methods of obtaining the above valuable materials from waste vehicle tyres. Such methods generally involve the reduction or pyrolysis of the tyres and distillation in order to obtain the oil content of the tyres. Not all of the methods proposed are economical in order to obtain these valuable materials.

The present invention seeks to provide an apparatus and method for the disposal of waste vehicle tyres in which the recyclable materials can be obtained economically and rapidly.

The present invention seeks to provide an apparatus, and method of using the apparatus in which the waste tyres are subjected to a pyrolytic action involving intimate contact between the waste materials and the heat source.

The present invention further seeks to provide an apparatus in which the heavier oils can be drained directly from a vessel in which the pyrolysis takes place.

Accordingly the present invention provides a vessel in which waste vehicle tyres can be subjected to a pyrolytic action, a heating element located within the vessel in intimate contact with a substantial proportion of the tyres within the vessel, a heat source to supply heat to the heating element, means for ensuring the substantial absence of oxygen from the vessel and means for carrying over volatile gases from the vessel for further treatment.

The present invention will now be more particularly described with reference to the accompanying drawing which illustrates one form of apparatus according to the present invention.

Referring to the drawing there is shown a pyrolytic apparatus (10) including a vessel (12) having a heating element (14).

In the present instance the heating element comprises a duct of convoluted form receiving a flow of hot air produced from a burner (16), the hot air being exhausted to atmosphere through an outlet (18) of the duct, or the heat can be used in a further portion of the apparatus.

The vessel (12) has an inlet duct (20) through which a supply of nitrogen gas flows in use. The vessel (12) has an outlet (22) through which the nitrogen flows together with volatile gases produced as a result of the pyrolytic process in the vessel (12).

The vessel (12) has a drain (24) and a collector (26) for the heavier oils produced as a result of the pyrolytic action taking place within the vessel (12).

The apparatus (10) also includes vessels (28) and (30) each of which contain water, the duct (22) discharging into the vessel (28) below the level of the water in that vessel. The vessel (28) has an duct (32) which discharges into the water within the vessel (30), and the vessel (30) has an outlet duct (34).

The vessel (28) also has a drain (36) for the water and an outlet (38) for liquids collecting on the top of the water within the vessel (28).

The duct (22) also has an outlet (40) and a collector (42) for liquid. The duct (22) also has a cooler in order to condense volatiles flowing through the duct (22).

In operation the vessel (12) is packed with waste vehicle tyres. The heating element (14) which can be of a convoluted or any appropriate form is in intimate contact with a substantial proportion of tyres within the vessel. Hot air at a temperature of approximately 13000C is supplied from the heater (16) and flows through the heating element and exhausts through outlet (18). Simultaneously nitrogen gas at slightly higher than atmospheric pressure is introduced into the vessel (12) through the ducts (20) in order to eliminate or reduce as far as possible any reaction of the waste material with any oxygen within the vessel. It will be appreciated that the waste materials are subjected to a pyrolytic action.

As a result of the pyrolytic action the heavier oils from within the vehicle tyres drains to the bottom of the vessel and can be removed through the outlet (24). The lighter volatiles are exhausted through the duct (22) which can be condensed by the cooler (44) if required. Any liquid oil carried over through the duct (22) can drain through the duct (40) into the collector (42). The lighter oils in gaseous form first flow into the water in the vessel (28) where the heavier of them tend to collect in liquid form on the surface of the water in that vessel. The oils now in liquid form can be removed through the outlet (38). The lighter oils in gaseous form are carried over into the water in the vessel (30) where they may condense as liquids on the surface of the water in that vessel.Alternatively the lighter gases and non-condensables together with the nitrogen can exhaust through outlet (34) where further treatment can take place.

It will be appreciated that the form of the heating element (14) can be of any appropriate shape so long as the heating element is in contact with as much of the surface area of the waste material within the vessel (12) as possible.

Also any form of condenser appropriate can be used in respect of the oils carried over in gaseous form from the vessel (12) through the duct (22). For example it may only be necessary to use one vessel containing water or it may be necessary to provide more than two vessels. Alternatively gas scrubbing or condensing apparatus can be used.

After the pyrolytic action is complete and the flow of the heavier liquid oils through the duct (24) has ceased and no further condensation of gaseous oils is taking place the remains of the waste tyres within the vessel (12) can be extracted. Such waste typically comprises the steel wiring used as bracing materials and the solid residue is in a friable form from which the oil has been extracted. Typically the residue is in a crumb like form which can subsequently be processed to obtain carbon black.

The purpose of the invention is to obtain useful materials from waste tyres economically and at a higher rate without the need for complex machinery.

The provision of a heating element which is in contact with a substantial proportion on the vehicle tyres within the vessel enables the heat to be applied rapidly to a large volume of waste material so that the pyrolytic action is relatively rapid.

Also it has been found that with an apparatus of this type the heavier oils tend to drain directly from the vessel without the need for any further processing. The lighter oils which are carried in a gaseous form are easily condensed and recovered.

Claims

1. A reaction vessel in which waste vehicle tyres can be subjected to a pyrolytic action, a heating element located within the vessel in intimate contact with a substantial proportion of the tyres within the vessel, a heat source to supply heat to the heating element, means for ensuring the substantial absence of oxygen from the vessel, and means for carrying over volatile gasses from the vessel for further treatment.

2. A reaction vessel as claimed in claim 1 in which the heating element comprises a duct of convoluted form receiving a flow of heated medium.

3. A reaction vessel as claimed in claim 2 in which the heated medium comprises a flow of hot air produced from a burner, the hot air being exhausted either to atmosphere or to a further portion of the vessel.

4. A reaction vessel as claimed in any one of the preceding claims having an inlet duct through which a supply of an inert gas flows and having an outlet through which the inert gas flows together with volatile gasses produced as a result of the pyrolytic process in the vessel.

5. A reaction vessel as claimed in claim 4 in which the inert gas comprises nitrogen.

6. A vessel as claimed in claim 4 including one or more receiving vessels containing liquid, the outlet from the reaction vessel containing the inert gasses and volatile gasses from the vessel discharging into the receiver vessels below the level of the liquid in the or each receiving vessel.

7. A reaction vessel as claimed in claim 6 in which the or each vessel has a drain for the liquid and an outlet for liquids collecting on top of the liquid in the receiver vessels.

8. A reaction vessel as claimed in claim 4 in which the liquid in the receiver vessels comprises water.

9. A reaction vessel as claimed in claim 4 in which the outlet duct includes a receiver vessel for liquids contained within the flow of inert gas and volatile gasses.

10. A reaction vessel as claimed in claim 4 in which the outlet duct includes condensing means.

11. A reaction vessel as claimed in any one of the preceding claims including a drain and collector for heavier oils produced as a result of pyrolytic action taking place within the reaction vessel.

12. A reaction vessel constructed and arranged for use and operation substantially as herein described and with reference to the accompanying drawings.