JP2869188B2 - Equipment for thermal decomposition treatment of solid substances harmful to the environment - Google Patents

Abstract

A system for the treatment of solid products whose disposal is detrimental to the environment, comprising a reactor successively incorporating a dehydration zone (1) and a thermolysis zone (2), characterised in that downstream of the thermolysis zone (2) this reactor comprises a cooling zone (3) and in that the dehydration zone is provided with a leakproof entry gate, the cooling zone is provided with a leakproof exit gate, and air locks isolate the thermolysis zone (2), on the one hand from the dehydration zone (1), on the other hand from the cooling zone (3) so as to limit the entries of air into the thermolysis zone during the introduction of the products and during the extraction of the residues, this thermolysis zone (2) being provided with a gas extraction line by virtue of which it is at reduced pressure. <IMAGE>

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for thermally decomposing solid substances which cause harm to the environment.

Such solids are generally stored or incinerated.
In the former case, the potential danger remains and is exacerbated by the potential for groundwater contamination. In the latter case,
The incineration temperature is high enough to result in premature equipment wear and high operating costs. In addition, the products of incineration are released uncontrolled into the atmosphere and do not provide sufficient assurance that they will not pollute the environment.

French patent 2106844 raises the temperature (800 to 1300
Disclosed is a garbage disposal apparatus comprising a continuous part (comparable to ° C.), through which the garbage is packaged with a porous packaging material. The garbage is gradually dehydrated and burns. However, this solution still requires high temperatures leading to premature wear and high operating costs.

It is an object of the present invention to overcome the above-mentioned disadvantages by allowing continuous pyrolysis at a suitable temperature, for example at about 600 ° C., by continuous management of solids decomposition.

The present invention relates to an apparatus for treating a solid substance which harms the environment, comprising a furnace apparatus for continuously integrating a dehydration section and a pyrolysis section, wherein the furnace apparatus has a cooling section downstream of the pyrolysis section. The dewatering section is provided with an air-tight opening and closing mechanism, the cooling section is provided with an air-tight opening and closing mechanism, and the air shut-off mechanism enters the pyrolysis section during insertion of solids and discharge of residues. In order to restrict the air, the pyrolysis section is separated from the dewatering section on the one hand and from the cooling section on the other hand, and said pyrolysis section is provided with a gas discharge pipe which keeps it at a positive pressure. And a processing device characterized by the following.

Each of the aforementioned parts is consequently separated into isolated chambers.

 Due to the preferred and combinable features of the present invention, there is no free oxygen in the pyrolysis portion.

The pyrolysis section is at a temperature between 400 ° C. and 750 ° C. and a pressure of 800 mbar or less.

According to another preferred feature of the invention, the solids to be treated are inserted into the furnace unit in a wagon, which is decomposed from the dehydration chamber to the pyrolysis chamber, for example by a rack and pinion mechanism or an electromagnetic drive. It passes continuously from the chamber to the cooling chamber. The wagon is a solid residue,
For example, glass, metal, and stone are made to remain within the cooling chamber as they are easily removed after cooling upon cooling.

The dehydration and pyrolysis chambers are fitted with a thermal reactor known as a catalyst distribution panel to which pure oxygen or air and pyrolysis gases resulting from pyrolysis decomposition are supplied, and to the inside or outside walls of the chamber. And the electric heating element.

Carbon dioxide and water vapor generated by the oxidation of the pyrolysis gas in the catalyst distribution panel contribute to the heat conduction and radiation of the solid matter.

The pyrolysis gas formed in the pyrolysis and the oxidizing gas formed in the catalyst distribution panel are cooled and purified in the gas cleaning device when discharged from the furnace device, and the water is condensed in the gas cleaning device. Non-condensable gases and condensed hydrocarbons of high atomic weight are separated.

Sulfur halide compounds are removed in the gas scrubber by dissolution in the scrubbing water.

Upon discharge from the furnace apparatus, the gas stream is directed to a gas scrubber where the carbon formed during pyrolysis decomposition is loaded and cooled.

Hydrocarbons and carbons with large atomic weights are recovered after being settled out of the wash water in a settling tank upon discharge from the gas scrubber.

The gas flow at the time of discharge from the gas cleaning device is sucked by a vacuum pump.

The gas from the vacuum pump is sent to a gas scrubber having, for example, an aqueous solution of potassium carbonate to remove carbon dioxide.

The purified pyrolysis gases of the sulfur halide compounds and carbon dioxide are used to heat the furnace equipment and the excess is stored for subsequent use.

The rate of thermal reaction in the pyrolysis chamber is controlled by adjusting electrical heating, catalyst heating by common temperature measurements, gas flow rates, and current controllers.

Objects, features and advantages of the present invention will become apparent from the following description, given by way of non-limiting example with reference to the following accompanying drawings.

 FIG. 1 is a plan view of an apparatus according to the present invention.

 FIG. 2 is a front view of an inlet portion of a furnace of the apparatus.

 FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is an enlarged view showing attachment of the panel 4 to the support member.

FIG. 1 shows a main plan of the present apparatus, and FIGS.
Indicates a predetermined detailed structure.

The device according to the invention has a solid object to be treated inserted therein,
The chamber 1 in which these solids are dewatered and the partially or completely dewatered solids are heated to a pyrolysis temperature, for example a temperature of about 600 ° C (typically between 400 ° C and 750 ° C) A pyrolysis chamber 2 and a cooling chamber 3 in which the solid residue of the heat treatment is cooled to room temperature.
And a furnace device for combining the above into one device. The heat exchange in this furnace arrangement is advantageously carried out at an average temperature of 600 ° C. and absolutely without the presence of free oxygen.

Decomposition products such as non-condensable gases, hydrocarbons with higher atomic weights, carbon, etc. are continuously monitored as they leave the unit and are recycled if necessary for further processing.

Operation at this temperature does not cause any significant wear of the device, thereby extending its life and reducing operating costs.

Each chamber is substantially sealed and separated from each other by a guillotine door 23 operated by a push-up device.
2 and the door between chambers 2 and 3 move vertically in a sealed housing and the lifting device is sealed by packing. Furthermore, closed doors are provided at the entrance to the chamber 1 and at the exit from the chamber 3, whereby the dewatering section 1 and the cooling section are deliberately separated from the external and / or pyrolysis section 2. These doors may move vertically or horizontally, but may alternatively be pivoted depending on the size of the furnace equipment, the space used and the intention of the designer.

It is understood that the seal provided by the inlet and outlet doors exists between the outside and the warmer parts 1 and 3 which are considerably lower than in the chamber 2.

In order to prevent air from entering the chamber 2, solids are inserted through the air shut-off device and the residue is discharged, and the air shut-off device is connected to the pyrolysis chamber when the fixed object is inserted into the dewatering chamber. From the cooling chamber as the residue is discharged from the third chamber.

Chamber units 1 and 2 are insulated to reduce heat loss (item 27).

Chambers 1 and 2 are provided with any suitable known type of heating means, two examples 4 and 5 being shown.
The temperature in the chamber 2 is maintained, for example, at about 600 ° C.
The inside is kept at a low temperature of 100 ° C. or more, for example, about 120 ° C.

The catalyst distribution panel 4, which incorporates a heating element 25 for heating the catalyst distribution panel 4 to a temperature at which catalytic oxidation of the feed gas is feasible, is shown at the ceiling of the chambers 1 and 2, but likewise suitably at the side walls It may be attached to. These panels reside in a housing that is sealed from the outside. FIG.
Shows how the panel 4 is fixed to the inner wall of the furnace apparatus and the arrangement of the seal member 26. This seal member is used to oxidize the mixed gas mixture (preferably, oxygen and pyrolysis gas). It works to force it to flow through. Room 3
The apparatus may include a device (not shown) for cooling the solid residue and for recovering heat for heating the gas supplied to the catalyst distribution panel.

The electric heating element 5 is connected to a transducer 6, which in this embodiment is mounted on the wall inside the furnace apparatus (alternatively outside) by means of an electrical connection via sealed through leads. Shown.

The pressure in chamber 2 should be less than 800 mbar, exactly 5
It is kept at 00 mbar. This pressure is preferably
Same for chambers 1, 2, and 3.

The gas mixture exiting the chamber 2 discharges it into the settling device 13 and flows into the gas washing device 9 to which cooled water is supplied from the water tank 14, where the water from the settling tank 13 Processed in a general manner. The condensed hydrocarbons and carbon separated from the aqueous solution in the tank 13 are:
It is sent to a storage tank 17, from which it is removed when needed.

Gas that is not condensed when discharged from the tank 9 is sucked by the pump device 10 so as to be discharged to the purification tank 11, in which carbon dioxide is removed from the tank.
The water from 14 is removed, for example, by adding potassium carbonate. Upon exiting the tank 11, the purified gas is compressed by the compressor 12 and stored in the tank 16.

In this embodiment, the compressed gas is further supplied to the catalyst distribution panel 4 via a mixer 15 which receives compressed air from any supply means 18 or, depending on the application, pure oxygen from an external storage device. Is done. The gas mixture flows through a heat recovery device 7, in which the gas mixture is heated to improve the thermal equilibrium of the oxidation reaction of the catalyst. FIG. 1 shows the exhaust of the catalytic reaction gas from the chamber 1. These gases comprise carbon dioxide and water vapor essentially as a result of dehydration and catalytic oxidation and are cooled through the heat recovery unit 7. These are sucked by the pump device 8 and discharged to the chimney 19.

FIG. 2 shows a wagon 20 in which the solids to be treated are installed, which wagon is moved from one chamber to the next by a rack and pinion device 21.

 Each wagon is moved simultaneously by a drive shaft 22.

Gas is exhausted from chambers 1 and 2 by floor grooves 24 at the end of the chamber to entrain carbon in the gas stream.

 Gas cleaning devices are common.

 The device described above has the following advantages.

This device can be applied to any quantity of solids by changing the cross-sectional area of the furnace device or the length of the furnace device, or by using multiple furnace devices in parallel when needed. it can.

The device according to the invention is capable of treating solids that are removed under the protection of good environmental conditions.

The product of the pyrolysis is cleansed of all contaminants and can be controlled before any subsequent use. Water in the form of an aqueous solution is generally treated after hydrocarbons and carbon have been precipitated and removed. Various inerts, such as glass, metal, etc., can be recycled under optimal hygiene. Heavy metals that do not evaporate in the pyrolysis furnace are collected by a wagon after cooling. The evaporated heavy metal is recovered by settling in a gas scrubber or settling tank.

Lastly, the device according to the invention is capable of storing energy recovered in the form of carbon and carbon dioxide, or being transported to consume them somewhere else, someday, thereby providing extraordinary energy recovery. Can be.

It goes without saying that the above description has been given by way of non-limiting example and that numerous modifications can be proposed by a person skilled in the art without departing from the scope of the present invention.

Claims (10)

(57) [Claims] 1. An apparatus for treating a solid which is harmful to the environment, comprising a furnace device for continuously integrating a dewatering section (1) and a pyrolysis section (2), wherein the furnace apparatus comprises a pyrolysis section (1). A cooling part (3) is provided downstream of 2), an airtight inlet opening / closing mechanism is provided in the dewatering part, an airtight outlet opening / closing mechanism is provided in the cooling part, and an air shutoff mechanism is provided for inserting solid objects. In order to limit the air entering the pyrolysis section during the discharge of the medium and residues, the pyrolysis section (2) is separated from the dehydration section (1) on the one hand and from the cooling section (3) on the other hand, A processing apparatus characterized in that the decomposition part (2) is provided with a gas discharge pipe for maintaining the decomposition part at a positive pressure. 2. The apparatus according to claim 1, wherein the pyrolysis section is maintained free of oxygen. 3. The device according to claim 1, wherein the pyrolysis section is at a temperature between 400 ° C. and 750 ° C. and a pressure of 800 mbar or less. 4. A device according to claim 1, wherein the solids are conveyed by a wagon (20) which is moved through the furnace device by a mechanism (21) such as a rack and pinion device. apparatus. 5. The apparatus according to claim 1, wherein the dehydration chamber and the pyrolysis section are heated by heating means having a catalyst distribution panel. . 6. The catalyst dispersing panel according to claim 5, wherein at least a part of the gas is supplied from a pyrolysis portion.
An apparatus according to claim 1. 7. Apparatus according to claim 5, wherein the steam generated by the catalytic oxidation contributes to the conduction and radiation heating of the solids to be treated. 8. A pyrolysis gas formed by a decomposition process by thermal decomposition and a gas formed by a catalytic oxidation process are cooled and purified in a gas cleaning device to remove sulfur halide compounds and carbon dioxide. Apparatus according to any of the preceding claims, characterized in that: 9. The apparatus according to claim 8, wherein the gas when the gas cleaning apparatus is discharged is sucked by a vacuum pump device. 10. The method of claim 1, wherein the thermal reaction rate is controlled by controlling electrical heating, catalyst heating using general temperature measurement, gas flow, and current control. An apparatus according to any one of claims 9