KR20010042978A - Installation for Thermolysis Processing of waste with Fumes That Have a Low Free Oxygen Content - Google Patents

Abstract

The apparatus of the present invention is connected to a pyrolysis chamber 12 for combustion of pyrolysis gas, a combustion chamber 19 for providing a supply of combustion gas, and a combustion chamber for combustion of gas generated in the pyrolysis chamber 12. Vortex burner 18 mounted on 19, a portion of the combustion gas produced in the combustion chamber is connected to combustion chamber 19 to perform post-combustion, whereby other portions of the gas to pyrolysis chamber 12 Supplied to burner 18 of combustion chamber 19 to produce combustion gas free of free oxygen at the post combustion chamber 23, preheated combustible oxygen supply line 22 to burner 18, and outlet of the combustion chamber. Means for controlling the amount of oxygen that is released.

Description

Installation for Thermolysis Processing of waste with Fumes That Have a Low Free Oxygen Content}

The present invention relates to the pyrolysis treatment of waste, for example industrial and / or municipal waste.

According to document EP-A-0 524 847, devices for industrial and / or municipal waste disposal are already known, in particular comprising a pyrolysis reactor operating in a vertical mobile bed.

More precisely, the waste is fed to the top of the pyrolysis reactor and moved to the higher or lower vertical reactor by gravity. Hot gases are introduced at the base of the reactor, seeping into the ascending flow through the waste material layer and gradually transferring their energy to the solids. These hot gases, according to one embodiment of the apparatus (the apparatus of FIG. 2 of the above document), comprise essentially the effluent resulting from the combustion of the pyrolysis effluent in the fluidized bed, the oxygen content of which is monitored. This monitoring of oxygen content is carried out by a control loop.

The hot solids, which essentially contain coke and minerals, exit the reactor via a line located at the bottom of the reactor.

According to the document, some waste materials have very heterogeneous properties, which cause significant fluctuations in the heating power of pyrolysis gas. Therefore, the combustion of these products with burners brings about the problem of flame stability.

The fluidized bed is chosen because the inherent thermal inertia of the fluidized bed ensures stable combustion of the pyrolysis gas even when the exothermic power of the combusted gas drops significantly.

As already mentioned above, part of the fumes produced by the reactor operating in fluidized bed is sent to the waste pyrolysis reactor and the remaining part is used to preheat the combustion air. Thus, the amount of combustion air introduced into the reactor operating in fluidized bed is controlled to permanently maintain a low oxygen content for the pyrolysis gas, as already mentioned.

According to the document, the oxygen content of the hot gas used for pyrolysis is less than 10% by volume, preferably less than 4% by volume.

The present invention seeks to improve the device of this type.

For this purpose, the present invention

-Pyrolysis chamber of garbage by direct contact with hot gaseous fluids,

A line for introducing hot gaseous fluid into the pyrolysis chamber,

A line for extracting gas present in the pyrolysis chamber and

A combustion chamber fluidly connected to the input line for supplying the pyrolysis chamber with combustion gases resulting from the combustion of the gas from the extraction line and the pyrolysis chamber to combust the gases exiting the pyrolysis chamber

Including,

A vortex burner connected to the extraction line and mounted in the combustion chamber to combust the gas exiting the pyrolysis chamber,

A post-combustion chamber fluidly connected to the combustion chamber, suitable for post-combustion of a portion of the combustion gases produced in the combustion chamber, the remainder of these combustion gases being fed to the input line,

A line for supplying the burner with combustible oxygen preheated to a predetermined temperature, and

Means for regulating the amount of oxygen supplied to the burners of the combustion chamber to produce combustion gases that are actually free of oxygen at the outlet from the combustion chamber;

Including, the present invention provides a device for pyrolysis treatment of garbage.

Due to this arrangement, the oxygen content of the combustion gas sent to the pyrolysis chamber can be optimally adjusted. In particular, the vortex burner allows for optimum mixing, thereby enabling optimal combustion of combustible oxygen with flammable pyrolysis gas diluted in very large volumes of inert combustion fumes from previous processing cycles.

Thus, the control means can be used to optimize the amount of combustible oxygen supplied to this burner so that the combustion gas to be re-injected into the pyrolysis chamber is virtually free of oxygen.

In addition, the post-combustion completes the oxygen depleted combustion that occurs in the combustion chamber for a portion of the combustion gas or mist that was not reinjected into the pyrolysis chamber.

Thus, at the outlet of the post-combustion chamber, it is possible to obtain combustion gases or mists with thermal energy which can be used directly without further treatment.

According to a preferred arrangement, the following points are optionally combined:

A heat exchanger is placed on the input line to preheat the combustible air to a temperature of up to 600 to 800 ° C .;

The burner is also fed propane or natural gas;

The combustion gas entering the pyrolysis chamber is maintained at a temperature around 450 to 750 ° C., preferably about 650 ° C .;

The pyrolysis chamber is maintained at a constant pressure between 100 mbar and 1.2 bar;

The post-combustion chamber supplies the combustion gas to the steam generator;

The solid residue from the pyrolysis chamber is sorted and the carbonized solid residue fraction is then sent to another combustion chamber for combustion, which also supplies another steam generator;

The steam fraction from each steam generator is globalized for use as an energy generating form for electricity generation.

These last part installations enable the on-site combustion of all combustible products from the waste to generate steam and thus electricity.

The pyrolysis chamber is carried by a carriage in which products move through the pyrolysis chamber by mechanical assembly. In this case, fluid connection means are provided which make a temporary fluid connection between the input line and the connection zone provided on the carriage and which are in communication with the reception zone of the solid product of the carriage.

According to another aspect, which is essentially the first, the pyrolysis chamber

-Openings for loading garbage, which may be sealed,

An opening for discharging the solid phase pyrolysis residue of the oven, which may be closed;

Means for receiving a fixed batch of rubbish in the oven,

Means for directly injecting the recycled pyrolysis gas constituting the hot gas into an oven and a fixed batch, so as to effect pyrolysis by direct contact of the hot gas with the waste, and

Outlet means for pyrolysis gas formed in the oven by pyrolysis treatment of the waste;

It consists of a batch oven comprising a.

The oven is of particular interest in that it enables the disposal of bulky waste, such as tires. More specifically, such an oven can be used in the case of an oven with a vertical fluidized bed, such as the subject of document EP-A1-0 524 847, where the input of the product is present when the product is heterogeneous, i. Resolve problems that interfere with the system for extraction.

Preferably,

The receiving means is movably mounted between a position for receiving the waste during the pyrolysis treatment and a position for discharging the solid phase pyrolysis residue through the discharge opening;

The receiving means is provided with means for discharging the hot gas into a fixed arrangement of rubbish, and the dispensing means is provided with means for injecting hot gas under the receiving means;

Cooling means are provided under the oven to cool the solid phase pyrolysis residue.

Other objects, features and advantages of the present invention may be seen in the following description provided with reference to the accompanying drawings as a non-limiting example.

1 is a schematic diagram of an apparatus according to a preferred embodiment of the invention, and

2 is a schematic front view of a longitudinal section of a batch filled pyrolysis oven according to the invention.

1 illustrates a preferred embodiment of the device according to the invention.

In this apparatus, the waste to be processed is sent to the grinder 9 and then filled into the carriage 11 by the conveyor system 10.

The carriage 11 used in the apparatus of FIG. 1 may be in the form described, for example, in international patent application WO-98 / 16594, in a form capable of injecting hot gas directly into the batch of waste to be treated.

Garbage-filled carriages 11 are then sent one by one into the pyrolysis chamber or oven 12 in which a closed inlet door 13 is fitted at the end.

In order to prevent oxygen from entering the pyrolysis oven 12 when transporting it from the carriage into the pyrolysis oven 12, the carriage 11 is operated by the loader (not shown) with the carriage 11 placed under an inert atmosphere. Can be sent to. Upon delivery of the carriage 11 into the oven 12, means for making a tight connection between the oven 12 and the loader, for example Bellows, are arranged to deliver the carriage 11 to the oven 12 under an inert atmosphere. do.

The apparatus includes a line 14 for introducing hot gaseous fluid into the pyrolysis oven 12. As described in more detail below, this hot gaseous fluid consisting of the combustion gas resulting from the combustion of the pyrolysis gas was previously extracted in the pyrolysis oven 12.

The input line has several branching lines 14a-14i, each of which has a fluid connection (for example FIG. 1) to make a temporary fluid connection between the input line 14 and the connection zone provided on each carriage 11. Termination by means of telescope bellows, which is not indicated in the figure, and connected with a band for accommodating the rubbish of these carriages 11. As already mentioned, this allows the injection of hot gaseous fluid directly into the batch of waste to effect pyrolysis.

Hot gaseous fluids (combustion gases, also referred to below as "fog") are pyrolysis maintained at a constant pressure between 100 mbar and 1.2 bar at a temperature between 450 ° C and 750 ° C, preferably at a temperature of 650 ° C. Is injected into the oven 12.

Thus, the waste is first dewatered, and then each carriage 11 is raised to its pyrolysis temperature as it advances into the pyrolysis oven 12 and is connected to a continuous branch line 14a-14i of the input line 14.

After the treatment, each carriage 11 filled with solid residue is recovered in an inert atmosphere, for example by a loader mentioned above, at the closed exit door 15 position of the oven 12.

In addition, the treatment of these solid residues will be described in more detail below.

The pyrolysis gas formed in the oven 12 is extracted in the oven by the extraction line 16 having several branch lines 16a-16i. This extraction is performed by pumping means located on the extraction line 16. These means are not shown in FIG. 1, but may consist of a suppressor, for example.

The input line 14 and the extraction line 16 are preferably first insulated so as to bring the hot pyrolysis gas into the combustion chamber and secondly to maintain the hot gaseous fluid at high temperature to be introduced into the pyrolysis oven 12 do.

The pyrolysis gas from the pyrolysis oven 12 is sent to the dust separator 17 by the extraction line 16. After dust removal in the gas, the pyrolysis gas is sent to the burner 18 of the combustion chamber 19 by line 20.

Burner 18 is a vortex burner of the type sold by BLOOM.

Burner 18 also specifically has an inlet 21 of propane or natural gas, which enables the supply of back-up, the provision of a support or pilot flame and the start of the pyrolysis process.

A line 22 for supplying combustible oxygen is also connected to the burner 18. Combustible oxygen may be pure oxygen or may come from air or certainly oxygen rich air.

Prior to injection into burner 18, this combustible oxygen is preheated to a temperature between 600 and 800 ° C. For this reason, the supply line 22 passes through the two heat exchangers 23 and 24 and passes through the next burner 18 to the afterburner chamber 25.

More precisely, the line 22 for supplying combustible oxygen is first connected to the backup burner 26 of the afterburner chamber 25, to the furnace 27 of the afterburner chamber 25, and to the furnace of the combustion chamber 19. Is connected to the outlet 28.

In this regard, it can be seen that in another embodiment, the mist delivery line can separate the furnace 27 and thus the post-combustion chamber 25 from the outlet 28 of the combustion chamber 19.

Burner 26 is also provided with an inlet 29 of propane or natural gas, which may be connected to the same source as inlet 21 of burner 18.

The oxygen amount adjusting means supplied to the burner 18 of the combustion chamber 19 is also provided at the outlet of this combustion chamber 19 to produce a combustion gas which is actually free of oxygen (preferably less than 0.5% oxygen content). These adjusting means are also used to adjust the amount of oxygen supplied to the afterburning chamber 25 in the case of the preferred embodiment of the present invention.

For example, there may be an oxygen meter 30 located on the input line 14 at the outlet of the combustion chamber 19 and connected to a servo control cock system schematically represented by 31 and located on the combustible oxygen supply line 22. Can be. The link between the oxygen meter 30 and the servo control cock 31 system is not shown on FIG. 1 for clarity.

Thus, a portion of the combustion gas or mist of the combustion chamber 19 exits the combustion chamber via line 14, which is provided with a pumping group 32 at its end. The remainder of the fumes not used for recycling into the pyrolysis oven 12 is sent into the afterburn chamber 25 to complete their combustion before being used as described below.

The fumes from combustion chamber 19 and afterburn chamber 25 pass through exchangers 23 and 24, respectively, to preheat combustible air to a temperature of up to 600 to 800 degrees. To this end, a combustible oxygen supply line 22, one end of which is connected to an oxygen source 33, followed by a pumping group 34, is used for the burners 18 and 26 through heat exchangers 23 and 24.

As an alternative, these two heat exchangers 23 and 24 can of course be replaced by one double circuit exchanger or certainly only one single circuit exchanger can be used.

Since the purpose of the apparatus of FIG. 1 is the in-situ treatment of all pyrolysis products, the fumes exiting the aftercombustion chamber 25 are fed via a line 35 passing through an exchanger 24, for example water 37 It is sent to the steam generator 36 of the double circulation boiler type.

In the case of the present invention, the generated steam is supplied to the turbo generator device 38 for generation of electricity. The condensate produced by this device is discharged by line 39. Alternatively, hot water may of course be produced with the fumes from the afterburning chamber 25 instead of generating electricity.

The cooled mist is extracted from the generator 36 through a line 40 in which a pumping group 41 is installed, which is sent to the bag filter 42 to separate the solid particles and discharge into the atmosphere through the stack 43. .

The pumping group 41, for example comprising an extraction fan, also regulates the separation between the mist for the oven 12 and the mist for the post-combustion chamber 25, wherein the flow rate is controlled by the pressure in the oven 12. .

In particular, the safety device to which the pumping groups or fans 32 and 41 are concerned also prevents the flow of oxygen from the afterburner chamber 25 to the combustion chamber 19.

Each carriage 11 filled with solid phase pyrolysis residue is sent by the loader to a cooling device 44 installed to prevent free oxygen from entering the loader.

In the device 44, this carriage 11 is emptied on the conveyor to cool the residue as it passes into the pool 45.

These residues are then washed at 46 and sieved at 47. Here, the sieve has a hole diameter of 8 mm. The particles which have passed through the sieve are then subjected to an abrasion step at 48 and then sieved again by a sieve 49 having a hole diameter of 0.8 mm. The carbonized fraction is separated from the inorganic fraction by this sieve.

The carbonized fraction is then subjected to a drainage step at 50 and then sent to silo 51 for storage. The inorganic fraction is subjected to the sorting step at (52). After this classification, the minerals 53, the magnetic body 54 and the nonmagnetic material 55 are recovered. In sorting, the metal also undergoes a pressing step.

Particles held in 47 by the sieve are sent to floating tank 56.

The most dense material (such as metal) is recovered at the bottom of the head and sent to 52 for separation. The least dense material (carbonated fraction) is recovered at the top of the head 56 and sent to the mill 57 to reduce to a size of less than 0.8 mm.

These carbonized particles are then drained at 50 and then sent to silo 51.

The silo 51 supplies a dense fluidized bed oven 58 for burning charcoal fractions or charcoal stored in the silo 51.

The mist produced in this oven 58 passes through a steam generator 59 supplied with water 60. The vapor fraction exiting this generator 59 is sent to the turbogenerator device 38 as it exits the generator 36.

In addition, the mist generated in the oven 58 passes through an economizer 61 that preheats combustible oxygen for the oven 58. This combustible oxygen is connected to the source 58 of pure oxygen, pure air or oxygen enriched air and sent to the oven 58 via a line 62 in which a pumping group 64 is installed.

Haze exiting the coke 61 is sent to the bag filter 42 via a line 65 with a pumping group 66.

The ash recovered at the bottom of the oven 58 is collected and discharged at 67, while the ash recovered at the top of the oven 58 is recycled into the oven via line 68.

One end of this line 68 is also connected to the bottom of the bag filter 42.

Exhaust exhaust residue exiting the bottom of the bag filter 42 is discharged at 69.

According to the alternative of FIG. 2, the pyrolysis chamber consists of a batch-filled pyrolysis oven 112.

This oven 112 is closed at its upper and lower ends during pyrolysis treatment by panels 170 and 171 that are movable vertically and translationally in the horizontal plane.

The panel 170 allows for somewhat transverse sealing about the longitudinal axis of this same oven 112 of the dripping opening of the oven 112, while the panel 171 allows the outlet opening of this oven 112 to be opened. For the purpose of closing the valve, which also extends somewhat transverse to the axis.

The discharge opening is opened into the landfill pool 172 for recovery of the solid phase pyrolysis residue.

A fixed tank 173 is mounted between the panels 170 and 171 in the oven 112 to discontinuously receive the stationary bed arrangement of waste to be treated.

The tank 173 is provided with a bottom consisting of a two-part grille 174. The two respective portions of the grate door 174 can pivot between a horizontal position where they extend from each other to accommodate a waste batch and a position away from each other for discharge through the discharge opening after removal of the plate 171.

The side inlet 175 for the recycled pyrolysis gas is opened into the oven 112 under the grate door 174. This inlet is connected to the input line 14 of the apparatus of FIG. 1 when the oven 112 replaces the horizontal oven 12 of FIG. 1. Thus, the recycled pyrolysis gas enters the batch of rubbish after passing through the grate door 174 to effect pyrolysis by direct contact of the hot gas with a fixed batch of rubbish to be treated.

The pyrolysis gas formed in the oven 112 is extracted in the oven 112 through the side outlet 176 connected to the extraction line 16 when the oven 112 is used as part of the apparatus of FIG. 1.

The oven 112 is supplied with waste by gravity by a loader 177 moving horizontally above the oven 112.

For this reason, a tank 178 similar to the tank 173 is installed in the loader 177. In this regard, it will be appreciated that the lower end of the loader 177 is not sealed.

According to an alternative of the method, the loader can be replaced by a loader which is fed to the oven through the side opening by a rolling belt.

The loader may also be mounted to move in a translational motion to provide an array of pyrolysis ovens.

Lateral injection of hot gas into the batch can also be envisioned.

It is also possible to provide lateral discharge of residue by means of a seat for receiving garbage mounted so as to be movable.

The foregoing description is provided by way of non-limiting example only, and of course, numerous variations may be proposed by those skilled in the art without departing from the scope of the present invention.

Claims (13)

-Pyrolysis chamber of rubbish by direct contact with hot gaseous fluids (12), A line 14 for introducing a hot gaseous fluid into the pyrolysis chamber, A line 16 for extracting gas present in the pyrolysis chamber, Supplying the combustion gas to the pyrolysis chamber which is fluidly connected to the extraction line 16 and which is produced by the combustion of the gas exiting the pyrolysis chamber 12 so as to combust the gas coming from the pyrolysis chamber 12 Combustion chamber fluidly connected to feed line 14 for Including, A vortex burner 18 connected to the extraction line 16 and mounted in the combustion chamber 19 for burning the gas exiting the pyrolysis chamber 12, A post-combustion chamber 25 fluidly connected to the combustion chamber 19 and suitable for post-combustion of a portion of the combustion gases produced in the combustion chamber 19, the remainder of these combustion gases being fed to the input line 14, A line 22 for supplying burner 18 with preheated combustion oxygen to a predetermined temperature and Means for regulating the amount of oxygen supplied to the burner 18 of the combustion chamber 19 to produce a combustion gas substantially free of free oxygen at the outlet of the combustion chamber 19. Apparatus for pyrolysis treatment of garbage, comprising a. The method of claim 1, wherein the pyrolysis chamber -Openings for inputting garbage, which may be sealed, Openings for discharging solid phase pyrolysis residues, which may be enclosed; Means (174) for receiving a fixed batch of rubbish in the oven, Means (175) for directly introducing the recycled pyrolysis gas constituting the hot gas into an oven, into a fixed batch, in order to effect pyrolysis by direct contact of the hot gas with the waste and Outlet means 176 of pyrolysis gas formed in the oven by pyrolysis treatment of the waste; Apparatus comprising a batch furnace comprising a. Apparatus according to claim 1 or 2, characterized in that a heat exchanger (23, 24) is arranged on the input line (14) to preheat the combustion air to a temperature of up to 600 ° C to 800 ° C. Apparatus according to any one of the preceding claims, characterized in that it also supplies propane or natural gas to the burners (18). 5. The device according to claim 1, wherein the combustion gas introduced into the pyrolysis chamber is maintained at a temperature of 450 to 750 ° C., preferably about 650 ° C. 6. 6. The device according to claim 1, wherein the pyrolysis chamber is maintained at a constant pressure between 100 mbar and 1.2 bar. 7. Apparatus according to any of the preceding claims, characterized in that the afterburning chamber (25) supplies the combustion gas to the steam generator (36). 8. The solid phase residue coming out of the pyrolysis chamber is sorted and sent to another combustion chamber 58 for burning the carbonated solid residue fractions produced therefrom and the other combustion chamber 58. ) Also supplies combustion gas to another steam generator (59). 9. Apparatus according to claim 7 or 8, characterized in that the steam fractions from each steam generator (36, 59) are globalized for use in the form of energy generation for generating electricity. An apparatus according to claim 1, characterized in that the pyrolysis chamber (12) is of the horizontal type and the waste is carried by a carriage (11) moving across the pyrolysis chamber by mechanical assembly. An apparatus according to claim 2, wherein the receiving means (174) is mounted so as to be movable between a position for receiving the waste during the pyrolysis treatment and a position for discharging the solid phase pyrolysis residue through the discharge opening. 12. The apparatus according to claim 2 or 11, wherein means for passing hot gas through the fixed arrangement of waste is provided to the receiving means, and the feeding means injects the hot gas under the receiving means. 13. Apparatus according to any one of claims 2, 11 and 12, wherein cooling means are provided below the oven to cool the solid phase pyrolysis residue.