EP2536811B1 - Gasification device and gasification method - Google Patents

Description

• eine Vergasungszone, in die über eine Einfüllöffnung der Feststoff einfüllbar ist,
• eine Oxidationszone zur Oxidation des erzeugten Gases ausgebildet ist, die mit der Vergasungszone zur Leitung des in der Vergasungszone erzeugten Gases in die Oxidationszone verbunden ist.

The invention relates to a gasification device for producing a flammable gas from a solid, comprising:

• a gasification zone into which the solid can be introduced via a filling opening,
• an oxidation zone is formed for oxidizing the generated gas which is connected to the gasification zone for conducting the gas generated in the gasification zone into the oxidation zone.

Another aspect of the invention is a gasification process for producing a flammable gas from a solid.

Gasification facilities or carburetor or gas generators of the aforementioned type and gasification processes are used to gas solid substances such as organic or inorganic carbonaceous materials, in particular wood, plants or plant residues, especially in pelletized form as completely as possible in a controlled process, to thereby to produce an ignitable, in particular combustible gas. Typically, this gas thus produced is burned in a process downstream of the gasification to thereby perform work and, for example, operate a power generator.

Out EP 1 865 046 A1 are known a gasifier and a gasification process, which in a shaft gasifier in a three-stage process by gasification of the solid, partial oxidation and thermal decomposition of the gas and reduction generates an ignitable gas. The disclosure of this patent application is incorporated by reference in its entirety EP 1 865 046 A1 included. A disadvantage of the prior art disclosed in this patent application is that gasification often succeeds only incompletely and that the amount of energy lying in the solid is thereby not completely exhausted. Another disadvantage of such prior art method or carburetor is that the carburetor tends to contamination during normal operation and thus relatively short maintenance intervals for its regular cleaning are required.

Out DE 1 037 051 . DE 198 46 805 and DE 102 58 640 Further gasification processes and carburetors are known which serve to gasify solids in an ignitable gas. These previously known methods also have the disadvantage that they do not completely exhaust the amount of energy resting in the solid in the form of a combustible gas, since the gasification process does not proceed in an optimum manner therein and that regular maintenance in short time intervals is required in order to function properly to ensure the carburetor or the effectiveness of the gasification process.

Out US 2009/0282738 For example, there is known an apparatus and method for producing biofuel having generally concentric chambers including a combustion chamber and at least one pyrolysis chamber. US 2007/0006528 shows a method and apparatus for producing a fuel gas from biomass. The apparatus includes a plurality of levels, each level including a plurality of radially extending air supply tubes. The air supply pipes are distributed over the circumference. Each level is supplied with variable air volumes.

It is an object of the present invention to provide a gasifier or a gasification process, which achieves a more efficient gasification of a solid. It is an object of the invention to extend the time intervals, which are between two necessary maintenance intervals at normal consumption of the gasification compared to the prior art with constant efficiency, or at least maintain it with increased efficiency, preferably to extend.

This object is achieved by a gasification device according to claim 1.

With the gasification device according to the invention, a gasification zone is provided, which is functionally divided with respect to the temperature control and air supply in at least two, preferably more than two gasification sectors. A functional division can be achieved, for example, in that the gasification sectors are not separated from one another by structural elements, but instead a separate air supply is provided for each gasification sector and the gasification sector essentially or at least in a temperature-relevant proportion from the air supply provided to it is supplied with air. Thus, although a total of contiguous and non-constructively divided gasification zone can be provided, which is virtually divided functionally due to the separate air supply in defined gasification sectors.

In addition, the gasification zone may also be divided by partitions such as partitions or the like such that transfer of solid and gas from one gasification sector to another gasification sector is not immediately possible, especially not directly, so that the gasification process in each gasification sector is largely isolated Process takes place.

According to the invention, the prevailing temperature is detected in each gasification sector. For this purpose, a corresponding temperature measuring device is provided which measures, for example, by means of a single temperature measuring instrument in successive measuring cycles, the temperature of the individual gasification sectors or which comprises a plurality of temperature measuring devices and a respective temperature measuring device is associated with a gasification sector.

The temperature measuring device is signal-wise coupled to a control unit which serves to set the temperature in each gasification sector in an optimal range for the gasification. It is to be understood that the control device can in particular regulate a closed control process in a control loop. The control device is in turn signal-technically coupled to an air supply unit which is designed to supply air to each gasification sector. In this case, each gasification sector can be supplied with an ideal air volume for the conditions prevailing in this gasification sector or, in certain situations, no air can be supplied. In principle, in the event that in a gasification sector too low a temperature, ie a temperature below the ideal process temperature in the reverse case, that is, too high a temperature above the ideal process temperature in a gasification sector, to reduce the supply of air to this gasification sector.

Instead of a temperature measuring unit according to the invention, another detection device can also be used, which allows a direct or indirect conclusion on the efficiency of the gasification process in the respective sector, for example an analysis device for determining the composition of the pyrolysis gas or parts thereof.

With the inventively developed Vergasurigseinrichtung gasification of a solid in a large gasification zone is achieved without the disadvantage that local effects, such as an accumulation of very large and dense amounts of solid in a region of the gasification zone or an unfavorable air supply in a Area of the gasification zone, the gasification is unfavorable. This is inventively achieved by the gasification zone in at least two, preferably several sectors, for example, four each over a peripheral portion of 90 ° extending gasification sectors is divided and the gasification based on the prevailing temperature and their regulation or control by air supply in each gasification sector separately is controlled or regulated. In principle, the gasification sectors may be evenly or non-uniformly distributed around the circumference and be provided with two, three, four, five or more sectors.

The oxidation zone is, based on its cross-section, at least partially, preferably completely surrounded by the gasification zone. Accordingly, the oxidation zone is arranged centrally within the gasification device by being surrounded by the gasification zone in relation to a cross section through the gasification device at least in a region, but preferably completely. As a result, in particular, an annular gasification zone is formed around the oxidation zone and consequently enables effective heat transfer from the gasification zone into the oxidation zone and vice versa. It should be understood that on the one hand by the supply of pyrolysis gas from the gasification zone in the oxidation zone, a convective heat transfer takes place, but through the environment of the oxidation zone with the gasification zone but also by direct heat conduction heat transfer can take place. In particular, this embodiment can be realized such that the gasification device is designed as a shaft carburetor and the oxidation zone is designed as centrally disposed within the Schachtvergasers oxidation chamber, which is surrounded by an annular gasification zone.

It is preferable to reform the gasifier by means of an air supply tube connected at its first end to the oxidation zone, in particular protruding into the oxidation zone, and connected at its other end to a source of oxygen-containing air. This training is executable or independently and without such a divided gasification zone, temperature measuring unit, control unit and / or air supply both in connection with the above-described, divided into several adjacent gasification sectors gasification zone and related temperature measuring unit, control unit and air supply. Through the air supply pipe, the oxidation zone can be supplied with air in an effective manner in order to carry out or force the oxidation of the pyrolysis gas there. The air supply tube preferably extends from an upper end of the gasification device in the longitudinal direction, in particular along the central axis of the gasification device, downwards in the direction of the oxidation zone.

It is further preferred that the air supply tube is at least partially disposed in a cover tube and an annular space between the air supply tube and the cover tube is formed, which is connected at its first end to the gasification zone and connected at its other end to a source of oxygen-containing air is.

By means of such a sheath tube, it is possible, in addition to the air supplied through the air supply tube of the oxidation zone, to further supply air with oxygen contained therein to another region, in particular into the gasification zone. This development is based on the finding that it is advantageous, especially when solids are to be subjected to efficient gasification, when the air supply takes place in a balanced and uniform manner, ie high local flow velocities are avoided, but at the same time a sufficiently high volume flow is provided to achieve as complete and efficient gasification as possible. Here, the introduction of the air over several supply sources and lines has proven to be particularly advantageous. In principle, the gasification zone, as described in the prior art, can be supplied with the air required for the gasification from the outside, for example via a plurality of air inlet pipes or nozzles projecting from the outside into the gasification zone. In particular, if but the gasification zone extends over such a cross-section that this cross-sectional components should also achieve an efficient gasification, which are spaced from the outside of this air supply, it is advantageous to provide a further, in the vicinity of these cross-sectional areas opening air supply. This can be done effectively by the sheath tube. The sheath tube may in principle be arranged so that it runs in the interior of the gasification device, in particular, if the gasification device is designed as a shaft carburetor, along and parallel, preferably coaxially to the longitudinal axis of the shaft gasifier. In this way, an introduction of air into a central region of the gasification zone, in particular in that region of the gasification zone which directly adjoins the oxidation zone, is made possible.

It should be understood that when the gasification zone is divided into a plurality of gasification sectors, the casing pipe may also be configured to have separate air ducts, in particular the same number as the number of gasification sectors, around the duct between the duct and the air duct To be able to adapt air individually to the needs of the respective gasification sector. This can be achieved for example by radially extending partitions, through which the annulus is divided into several annulus sectors and these annulus sectors are subjected to an individual air mass flow.

Basically, it should be further understood that the term "air" in particular ambient air can be understood, but this gas or gas mixtures are to be understood, which differ from the composition of the ambient air, especially for example gas mixtures containing an increased proportion of oxygen or Gas mixtures to which are admixed components which act as a catalyst or which contain particular gasification or oxidation-promoting components or components which prevent deposits within the gasification apparatus. In particular, these proportions may be gaseous fractions. In addition, however, the proportions can also be added in liquid form, for example in the form of an aerosol or in solid form, for example in the form of a powder. In particular, the supplied air can be enriched in certain process situations with water or steam in order to favorably influence the pyrolysis or gasification or oxidation or, as explained below, reduction.

According to a further preferred embodiment it is provided that the oxidation zone is arranged in an oxidation chamber bounded by one or more walls, in particular limited to the gasification zone, and that at least segments of these walls, preferably all walls, are movable with respect to the gasification zone are guided, in particular are guided rotatably. It should be understood that this training may be practiced in combination with the previously discussed partitioning of the gasification zone in gasification sectors and the temperature measuring unit and the control unit and / or the air supply means or without this division and units or devices, i. insofar represents an independent training a gasification of the initially described construction.

By the possibility of this training, the walls at least partially, but in particular to move a total, a relative movement between the stored in the gasification solids and the moving walls is achieved, whereby the structure of adhering to these walls solid layer, for example by precipitation from the pyrolysis gases , can be effectively prevented. On the one hand, this build-up of precipitates or deposits can reduce the efficiency of the gasification, on the other hand impair or disturb the above-mentioned functioning of the gasification device. In particular, the movement can be carried out as a rotational movement, for example about the longitudinal axis of the gasification device, in particular if the gasification device is designed as a shaft gasifier. However, other forms of movement are conceivable, for example translational movements. On the one hand, the mode of movement may be a continuous movement in one direction, but in certain applications, reciprocal, that is to say reciprocal, are also involved. reciprocating motion forms with a regular direction of motion reversal advantageous.

In this case, if an air supply pipe is provided, be provided in particular that the walls or wall segments are mechanically coupled to the air supply pipe for transmitting a movement, in particular a rotational movement and preferably an actuator is provided, which is coupled to the air supply pipe for introducing the movement, or the rotational movement. Through this mechanical coupling, an effective and structurally reliable transmission of the movement to the wall or walls is achieved, which define or limit the oxidation zone. In particular, both a translational movement direction, for example in the longitudinal direction of a gasification device designed as a shaft carburetor or a rotational movement, can be provided via the air supply tube, be realized, for example, about the longitudinal axis of a gasification device designed as a shaft carburetor or a motion form composed thereof.

In this case, it is even more preferable if one or more blade elements are arranged on one or more walls of the oxidation chamber, which extend from the walls into the gasification zone and are designed to move by movement of the wall or of the wall segment to which it is attached are to cause a conveying, crushing or mixing movement in the solid in the gasification zone. Such blade elements, which may be embodied, for example, in the form of paddles, rods, blades with or without twisting, cause mixing and optionally comminution and / or promotion in the solids region into which they extend when they extend relative to this move. For this purpose, the blade elements may be arranged on a plane or staggered with respect to one another, for example along a helical line on the outer surface of the walls delimiting the oxidation zone, and in particular arranged circumferentially about a longitudinal axis of a gasification device designed as a shaft carburetor. Such blade elements can contribute to a more homogeneous composition of the solids in the region of the gasification zone both in a translatory, but in particular in a rotating movement of the wall element or the wall / walls to which they are attached and thereby achieve a more efficient gasification.

Still further, it is preferable to reform the gasification device according to the invention by a reduction zone which is connected to the oxidation zone for supplying the raw gas formed in the oxidation zone and is designed to reduce the raw gas supplied to it. In the reduction zone, in particular by means of coke, which is conveyed from the gasification zone into the reduction zone and composed of degassed solid residues, a fuel gas can be generated from the pyrolysis gas processed in the oxidation zone. In this case, filtering of solid constituents by the coke in the reduction zone can furthermore be achieved. Alternatively or additionally, however, other methods for filtering, for example by means of filter candles or the like may be provided.

Still further, it is preferable to upgrade the gasification apparatus of the invention by comprising: an arrangement of the gasification zone and the oxidation zone in a shaft carburetor having a top opening for filling with the solid to be gasified, in which the gasification zone is arranged below the filling opening and the gasification zone is at least partially annular and surrounds the oxidation zone, wherein the oxidation zone is preferably arranged centrally with respect to the cross section of the shaft gasifier and one or the air supply pipe extending from the oxidation zone along the longitudinal axis of the shaft gasifier and is rotatably mounted for transmitting a rotary motion to a limiting the oxidation zone wall or more oxidation zone bounding walls.

With the gasification apparatus thus formed, a pit gasifier is provided in which a gasification zone and an oxidation zone are arranged adjacent to each other in such a manner that the oxidation zone is formed as a central oxidation chamber and surrounded by the gasification zone and thus spaced from a serving as a housing outer wall of the pit gasifier , The shaft carburetor may in particular be cylindrical, i. be round in cross-section, whereby an annular gasification zone bounded by round side walls can be formed therein. In other embodiments, however, other geometrical configurations of the shaft gasifier, for example with a rectangular or square cross-section, are advantageous, in which case the annular gasification zone is defined by correspondingly formed contiguous gap sections between the outer wall of the shaft gasifier forming the housing and the walls delimiting the oxidation zone. Basically, this is to be understood that in the shaft gasifier gravity-induced, especially exclusively by gravity generated transport of solids from an upper filling opening for fresh, un-gassed material and a lower export opening for degassed material (coke) is effected, one by blade elements, such as previously described, local mixing or conveying of the solid in or against the direction of gravity is hereby included in the invention and is also understood as a general gravity-induced transport of the solid.

The embodiment as a shaft carburettor according to this further development can in particular with the above-described features, such as the air supply pipe, the arranged thereon Umhüllungsrohr for supplying air into the inner region of the gasification zone and / or the division of the gasification zone into several gasification sectors with a corresponding temperature measuring unit, control unit and air supply means are trained. It should be understood that the formation of a shaft gasifier is particularly suitable to with the in the characterizing part of claims 1 and / or 3 and / or 5 defined in insulated manner or combined manner can be developed and this case also appropriate training can be provided according to the further subclaims.

It is particularly preferred in the embodiment described above as a shaft carburetor to provide a reduction zone which is arranged below the gasification zone and the direct transfer of solids from the gasification zone into the reduction zone allows and preferably a portion of the oxidation zone is arranged so that it the gasification zone separates in the flow direction of the generated gas from the reduction zone. In this reduction zone, as explained above, from the pyrolyzed and oxidized or cracked raw gas from the oxidation zone, a fuel gas can be produced to produce an additional filtering effect.

It is further preferred that the reduction zone for receiving pyrolyzed solid from the gasification zone is formed and arranged so that the pyrolyzed solid passes by gravity from the gasification zone in the reduction zone and at the lower end of the reduction zone, a movable grate is arranged for screening the ash falling down in the reduction zone. With this training, a particularly effective reduction in the reduction zone is achieved. Furthermore, it is to be understood that the grate, on the one hand, is translationally reciprocal or continuously rotatable in order to promote a fall of small coke and ash fractions into an underlying chamber, on the other hand, the grate may also be vertically movable, thereby altering the height of the reduction zone and to adapt to the process flow or the supplied solids.

The gasification device according to the invention can be further developed by a pressure measuring device which is designed to measure a pressure difference over at least part of the flow path of the gas generated inside the gasification device and is signal-coupled to a control device which is signal-technically coupled to an actuator for moving a grate upon movement, discharges fines from the packed bed of solids within the reduction zone into a plenum, wherein the controller is configured to actuate the actuator when a predetermined pressure differential is exceeded and is preferably configured to terminate the actuator actuation when a lower, predetermined pressure differential is undershot , With this training, a pressure-dependent removal of fines within the solids bed is effected, thus achieving an efficient operation. The pressure difference can in particular over the entire flow path starting from the ambient air, which enters the gasifier as fresh air, up to the outlet for the finished fuel gas from the gasifier.

With this development, an operation method is enabled in which a pressure difference is measured over at least part of the flow path of the generated gas and a grate is moved by means of an actuator to remove fines from the reduction zone when the measured pressure difference exceeds a predetermined value, and preferably Movement of the grate is stopped when the pressure difference falls below a smaller, predetermined value.

It is to be understood that this embodiment as a device or method can also be carried out independently of the division of the degassing zone into a plurality of sectors and the corresponding separate air supply devices and temperature measuring devices and the process control corresponding thereto.

A further aspect of the invention is a gasification process according to claim 11. The gasification process according to the invention can be carried out in particular with the above-described gasification device and is characterized by a particularly effective process control in the gasification zone by dividing these into individual process chambers in the form of the gasification sectors and in these gasification sectors, a separate temperature monitoring and control or regulation takes place, a particularly efficient gasification is achieved.

The gasification process may alternatively or in addition to this division of the gasification zone into gasification sectors be formed by the oxidation zone is arranged in a chamber which is bounded by one or more walls which are moved, in particular rotated. By this movement, in particular rotation, the formation of deposits on the walls or the wall of the oxidation chamber is prevented or at least reduced.

In this case, it is further provided that on the or the moving walls blade elements are arranged, which extend into the gasification zone and comminuted by the blade elements of the solid mechanically mixed and / or stirred. By means of such blade elements, an effective mixing of the solids in the region of the gasification zone is achieved, thereby making the gasification more efficient. Finally, in the gasification process according to the invention, as an alternative to dividing the gasification zone into several gasification sectors or in combination with it and alternatively or in combination with the configuration of the oxidation zone with moving boundary walls, it is further preferred that air is supplied to the oxidation zone via an air supply pipe and the gasification zone via a gasification zone Air is supplied to the air supply tube surrounding the cover tube and that the wall or walls of the oxidation zone are preferably rotated by means of the air supply tube. With this further development form, a particularly efficient air supply into the gasification zone is achieved by not only providing the air supply from the outside via the outer walls of the gasification device, as in the prior art, but additionally also an air supply from the inside and into the inner region of the gasification zone takes place. Here, in particular when the gasification zone is divided into several gasification sectors, it is to be understood that the casing tube and the annulus formed thereby between the casing tube and the air supply tube can also be divided into a plurality of peripheral sectors, thereby individually controlling the air in the individual gasification sectors independently of one another be able to supply and connects the individual peripheral portions of the annular space for this purpose to a corresponding individually regulating air supply device. In this context, in particular a correspondingly individual detection of the temperatures in the individual gasification sectors and a control of the air supply to the individual gasification sectors taking place as a function of these measured variables can take place, whereby it is to be understood that this individual air supply is controlled on the one hand by the air supplied from outside the individual gasification sectors, on the other hand can be done by the air supplied from the inside into the gasification sectors or by both feeding measures.

The invention will be further explained in more detail by way of exemplary non-limiting preferred embodiments.

Fig. 1

eine längsgeschnittene Seitenansicht einer bevorzugten Ausführungsform der erfindungsgemäßen Vergasungseinrichtung.

Fig.2

eine schematische, teilweise längsgeschnittene schematische Seitenansicht eines Details einer zweiten Ausführungsform der erfindungsgemäßen Vergasungseinrichtung und

Fig. 3

eine entlang der Linie A-A in Fig. 2 quergeschnittene schematische Draufsicht eines Details der zweiten Ausführungsform der erfindungsgemäßen Vergasungseinrichtung.

Show it:

Fig. 1

a longitudinal sectional side view of a preferred embodiment of the gasification device according to the invention.

Fig.2

a schematic, partially longitudinally sectioned schematic side view of a detail of a second embodiment of the gasification device according to the invention and

Fig. 3

one along the line AA in Fig. 2 cross-sectional schematic plan view of a detail of the second embodiment of the gasification device according to the invention.

Referring first to Fig. 1 a shaft gasifier is shown, which is bounded by a substantially cylindrical housing 10 with a circumferential housing wall to the environment. At the upper end, a cover 11 is arranged and closes the top of the housing with the exception of a central passage opening 12. Through the passage opening 12, an air supply pipe 20 and a surrounding this air supply pipe surrounding pipe 30 is guided. The air supply tube 20 and the sheath tube 30 extend centrally longitudinally along the central longitudinal axis 13 of the carburetor.

A filling opening 40, which is closable by means of a cover 41 and adjoins a sloping from top to bottom, with respect to the central longitudinal axis 13 obliquely extending channel 42 is disposed in the upper region of the carburetor and serves to supply solid. The channel 42 opens into a gasification zone 50, in which solid is placed and subjected to pyrolysis.

The gasification zone 50 is disposed between the outer wall 10 of the gasifier and a central oxidation chamber 60 and is separated from the oxidation zone 60 by a cylindrical wall 61. As a result, the gasification zone 50 is of annular design and surrounds the oxidation zone 60 on all sides in a horizontal cross section.

Into the gasification zone 50 is injected via air inlet nozzles 71a, c 72a, c, which extend in the radial direction to the central longitudinal axis 13 and are introduced in a circumferential row in the housing wall 10, air with an oxygen content. The air supply pipes 71a, c 72a, c are arranged in a total of two planes and distributed uniformly over the circumference of the carburetor.

The air inlet nozzles 71a, c are surrounded by an externally attached to the housing 10 annular channel 75a, c, through which the air is circumferentially distributed to all air inlet nozzles. Air is introduced from outside into the annular channel 75a, c via openings 76a, c. In the same way, the air inlet nozzles 72a, c are surrounded by an annular channel 77a, c arranged externally on the housing 10, can enter the air via openings 78a, c and via which the air is distributed circumferentially to all the air inlet nozzles 71a, c 72a, c.

Between the air supply pipe 20 and the sheath pipe 30, an annular space 31 is formed through which also air is passed, which is supplied via an air inlet pipe 32 to the annular space 31 from an air source. For this annular space 31, the air enters a total of four circumferentially distributed and offset by 90 ° to each other air pipes 33, 34, which extend radially from the annular space 31, starting outwards. From the air pipes 33, 34, the air exits at the outer end and is deflected obliquely downward into the annular gasification zone 50. As a result of this, the gasification zone 50 is supplied with air from outside via the air inlet nozzles 71a, c, 72a, c, and air is supplied from the inside via the air pipes 33, 34, resulting in a uniform penetration of the solids in the gasification zone 50 with air.

Above the air tubes 33, 34, the oxidation zone 60 is covered by a conical housing section 62 sloping downwardly from above, thereby facilitating the supply of solids from the feed channel 42 into the gasification zone 50 solely by gravity.

By means of temperature sensors, which are inserted in openings 51a, c and 52a, c, the temperature in the gasification zone is measured.

The pyrolysis gas obtained in the gasification zone 50 by pyrolysis passes through openings 63 a-d, which are distributed on a horizontal plane circumferentially on a cylindrical housing 61 in the oxidation zone. In the oxidation zone, the raw gas is substoichiometrically converted by partial oxidation and thermal cracking into short carbon chains at a temperature of about 1000 ° C or more. For this purpose, air is supplied via the air supply tube 20 of the oxidation zone via an air inlet channel 21 as an oxidizing agent, which exits from a plurality of circumferentially distributed at the lower end of the air supply pipe 20 openings 22. At the lower end of the air inlet tube, an end-side axial opening 23 is arranged, which serves to receive an upper temperature sensor.

The solids pyrolyzed in the gasification zone 50 continue to slide downwards due to gravity and are conveyed through obliquely outwardly downwardly arranged conical baffles into an inner, cylindrically delimited reduction zone 80. This promotion is also solely due to the influence of gravity. The partially oxidized in the oxidation zone and thermally cracked raw gas is withdrawn via a discharge channel 90, which is inserted into the housing wall 10 at the lower end of the carburetor. The entire gas flow guide within the carburettor is effected solely by a vacuum applied to the exhaust duct 90, with which the fuel gas is withdrawn from the carburetor.

The temperature in the gasification zone is measured by means of temperature sensors inserted in openings 51a, c. In total, four openings 51a-d offset by 90 ° are provided (the openings 51b, d are outside the cutting plane and are not visible or hidden by the oxidation zone). By means of the temperature sensors in the openings 51a-d, the temperature in the degassing sectors can be measured separately, as follows Fig. 3 described in more detail.

By means of a temperature probe tube 65, which extends from the outside into the lower region of the oxidation zone 60 which is remote from the air supply via the air supply tube 20, the temperature in the oxidation zone can be measured by means of a temperature probe. The temperature thus measured represents a reliable value for the process temperature in the oxidation zone and is used to control the supply of the oxidizing agent, in this case the air, by means of a control device in the oxidation zone as an input variable.

On the way from the oxidation zone 60 to the exhaust pipe 90, the partially oxidized and thermally cracked raw gas flows through the coke located above a grate 100, which is produced from the solid gasified in the gasification zone 50 and falls downwards. As a result, the raw gas is passed through the stored on the grid 100, fully degassed coke and thereby filtered and chemically reduced. The raw gas then ultimately withdrawn through the opening 90 is therefore of high quality and extremely low in tar.

The grate 100 is guided by means of rollers 101 for a translational reciprocal movement and can be coupled by means of a rod 102 to a corresponding actuator. The movement of the grate causes fine ashes and particles to fall through into a collecting space 103. The rust movement is controlled as a function of a pressure difference. The pressure difference is calculated from the negative pressure at the outlet duct 90 and the ambient pressure. When a predetermined pressure difference is exceeded, a rust movement is performed until the pressure difference has dropped below a lower, predetermined value.

Fig. 2 shows a section of a second embodiment. Evident is an oxidation zone 160, which is delimited by a cylindrical wall 161. As in the first embodiment, the oxidation zone 160 is bounded at its upper end by a conical housing wall 162, in which an air supply pipe 120 and a sheath tube 130 enclosing it is inserted. Also in this case, the air supply pipe and the sheath tube is rotatably supported and can rotate about the longitudinal axis 113 of the carburetor. This will both the housing wall 162 as well as the housing wall 161 set in rotation about the central longitudinal axis 113, which prevents deposition of pyrolysis gas constituents and the formation of constituent layers on these walls.

In addition, a plurality of blades 164 a-f are attached to the cylindrical housing wall 161. Each blade 164 a-f extends from the housing wall 161! radially outward and thus penetrates the gasification zone. The blades 164 a-f are vertically staggered to each other along a helical line on the housing wall 161. As the housing 161 rotates, the blades 164a-f effect mixing and loosening by means of upward transport of the particulate matter disposed in their zone in the gasification zone thereby producing a homogeneous and efficient gasification of this solid.

The air inlet nozzles 171a, c, 172a, c are arranged above the plane in which the uppermost blades 164 a-f are located, where they introduce air into the gasification zone from the outside. In addition, as already described above, air is supplied from the inside via the annular space between the sheath tube 130 and the air supply tube 120.

In Fig. 3 For example, a horizontal cross section through the carburetor is shown at the level of the openings in the oxidation chamber wall 61 and 161 and the air inlet nozzles 171a, c, respectively. How out Fig. 3 can be seen, enters from an annular channel 175 ad through a plurality of radially formed in the housing 110 openings 171a-d air in the gasification zone 150a-d.

The annular channel is subdivided into four annular channel sectors 175a-d by means of radially extending partition walls 179a-d, which are spaced apart by 90 ° in the circumferential direction. Air may enter each annular channel sector 175a-d via one air inlet port 176a-d, respectively, and this air supply may be individually controlled in amount for each annular channel sector 175a-d.

From the ring channel sectors 175a-d, the air enters the gasification zone via respective air inlet nozzles 171a-d respectively associated with each ring channel sector. This effects a functional separation of the gasification zone into four gasification sectors 150a-d with regard to the air supply and consequently the temperature control. In each gasification sector, the temperature is measured individually and the air supply is controlled or regulated accordingly. Depending on the temperature thus measured, the air supply to each gasification sector is controlled individually via a corresponding throttle by means of a control device 155. At too low a temperature for optimum pyrolysis, the air supply is increased, at too high a temperature for optimum pyrolysis, the air supply is throttled. It is to be understood that for each gasification sector to be controlled separately, a separate temperature measuring probe and an air supply device to be controlled separately are provided. The control / reboiling can be done via a single or a common electronic control unit.

From the gasification sectors 150a-d, the pyrolysis gas enters the central oxidation zone 160 via openings 163 where it is converted by partial oxidation and thermal cracking. From there, the raw gas enters down into the reduction zone and is withdrawn via the exhaust pipe from the carburetor.

Claims (15)

1. Gasification device for generating a combustible gas from a solid, comprising:

   - a gasification zone (50) which can be filled with the solid via a filling orifice (40),

   - an oxidation zone (60) for oxidising the generated gas which is connected to the gasification zone in order to direct the gas generated in the gasification zone into the oxidation zone,
   which gasification zone is divided into several mutually adjacent gasification sectors (150 a-d), a temperature measuring unit (51a, c) being provided which is configured to measure the temperature prevailing in each gasification sector respectively, and the temperature measuring unit is coupled in a signal transmitting arrangement with a control unit (155) which is coupled in a signal transmitting arrangement with an air supply system (171a-d, 175a-d, 176a-d) configured to supply each gasification sector individually with air, and the quantity of air supplied per time unit respectively to each gasification sector is dependent on the temperature measured therein,
   characterised by a reduction zone, which is provided as a means of conveying the pyrolysed solid out of the gasification zone into the reduction zone by gravitational force and which is connected to the oxidation zone for supplying the crude gas generated in the oxidation zone in order to reduce the crude gas supplied to it, and
   characterised in that the oxidation zone (60, 160) is at least partially, preferably completely, surrounded by the gasification zone (50, 150) by reference to its cross-section.
2. Gasification device as claimed in claim 1,
   characterised by an air supply pipe (20; 120) which is connected to the oxidation zone at its first end, in particular extends into the oxidation zone, and to a source of air containing oxygen at its other end.
3. Gasification device as claimed in claim 2,
   characterised in that the air supply pipe is disposed in a casing pipe (30, 130) at least in certain sections, and an annular chamber is formed between the air supply pipe and the casing pipe which is connected at its first end to the gasification zone and by its other end to a source for air containing oxygen.
4. Gasification device as claimed in one of the preceding claims,
   characterised in that the oxidation zone is disposed in an oxidation chamber which is bounded by one or more walls (61, 62; 161, 162), in particular sectioned off from the gasification zone, and at least segments of these walls, preferably all of the walls, are designed so that they can be moved relative to the gasification zone, in particular are designed so that they can be rotated.
5. Gasification device as claimed in claim 2 or 3 and 4,
   characterised in that the walls (61, 62) respectively wall segments are mechanically coupled with the air supply pipe (20) in order to transmit a movement, in particular a rotating movement, and an actuator is preferably provided which is coupled with the air supply pipe in order to impart the movement respectively rotating movement.
6. Gasification device as claimed in claim 4 or 5,
   characterised in that one or more paddle elements (164 a-d) are disposed on one or more walls of the oxidation chamber extending out from the walls into the gasification zone and configured to impart a conveying or mixing movement to the solid in the gasification zone due to the movement of the wall or wall segment to which they are attached.
7. Gasification device as claimed in one of the preceding claims,
   characterised by an arrangement of the gasification zone and the oxidation zone in a shaft gasifier having a filling orifice at the top end to enable filling with the solid to be gasified, the gasification zone being disposed underneath the filling orifice, and the gasification zone is of an annular design in at least certain sections and surrounds the oxidation zone, and the oxidation zone is preferably centrally disposed with reference to the cross-section of the shaft gasifier and a respectively the air supply pipe extends out from the oxidation zone along the longitudinal axis of the shaft gasifier and is mounted so as to be rotatable in order to transmit a rotating movement to a wall bounding the oxidation zone or several walls bounding the oxidation zone.
8. Gasification device as claimed in claim 7,
   characterised in that a reduction zone is disposed underneath the gasification zone and is connected to it to enable a direct transfer of solid from the gasification zone to the reduction zone, and a section of the oxidation zone is preferably disposed so that it separates the gasification zone from the reduction zone in the direction in which the generated gas flows.
9. Gasification device as claimed in claim 8,
   characterised in that the reduction zone is configured to receive pyrolysed solid from the gasification zone and is disposed so that the pyrolysed solid passes from the gasification zone into the reduction zone by the effect of gravitational force, and a movable grate is provided at the bottom end of the reduction zone for screening the ash dropping down into the reduction zone.
10. Gasification device as claimed in one of the preceding claims,
    characterised by a pressure measuring device which is configured to measure a pressure difference across at least a part of the flow path of the generated gas inside the gasification device and which is coupled by a signal transmitting arrangement with a control unit which is coupled by a signal transmitting arrangement with an actuator in order to move a grate which discharges fine components of the solid bulk inside the reduction zone to a collection chamber when moved, and the control unit is configured to operate the actuator if a predefined pressure difference is exceeded and is preferably configured to terminate operation of the actuator if there is a drop below a lower, predefined pressure difference.
11. Gasification method for gasifying a combustible gas from a solid,
    comprising the steps:

    - feeding solid into a gasification zone,

    - gasifying the solid in the gasification zone by means of pyrolysis respectively gasification,

    - feeding the pyrolysis gas generated in the gasification zone into an oxidation zone which is at least partially, preferably completely, surrounded by the gasification zone by reference to its cross-section,

    - feeding air into the oxidation zone and converting the pyrolysis gas into a crude gas in a sub-stoichiometric process by means of partial oxidation and cleavage in the oxidation zone,

    - feeding the oxidised pyrolysis gas out of the oxidation zone into a reduction zone,

    - feeding partially or completely pyrolysed solid into the reduction zone,

    - reducing the oxidised pyrolysis gas to a fuel gas in the reduction zone by means of the pyrolysed solid,

    characterised in that the gasification takes place in several gasification sectors of the gasification zone, the temperature of every gasification sector is measured and air is fed to every gasification sector in a quantity dependent on the temperature respectively measured therein.
12. Gasification method as claimed in claim 11, characterised in that the oxidation zone is disposed in a chamber which is bounded by one or more walls which are moved, in particular rotated.
13. Gasification method as claimed in claim 12,
    characterised in that paddle elements are provided on the moved wall or walls which extend into the gasification zone and the solid is mechanically mixed or stirred by means of the paddle elements.
14. Gasification method as claimed in one of preceding claims 11 - 13,
    characterised in that the oxidation zone is supplied with air via an air supply pipe and the gasification zone is supplied with air via a casing pipe surrounding the air supply pipe, and the wall or walls of the oxidation zone are moved in rotation preferably by means of the air supply pipe.
15. Gasification method as claimed in one of preceding claims 11 - 14,
    characterised in that a pressure difference is measured across at least a part of the flow path of the generated gas and a grate is moved by means of an actuator in order to discharge fine components from the reduction zone if the measured pressure difference exceeds a predefined value and the movement of the grate is preferably terminated if the pressure difference drops below a lower, predefined value.

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