EP2886190B1 - Method and device for the removal of impurities - Google Patents

Description

The present invention relates to a method and a device for discharging contaminants from a gasifier for carbon-containing material, in particular a fluidized bed gasifier or fluidized bed reactor.

From the DE 10 2007 012 452 A1 a device for gasifying organic substances in a floating bed is known. The fluidized bed gasification describes a graded gasification process in which, after pyrolysis or carbonization of a carbonaceous material to a type of coke, the most complete gasification of the coke produced takes place together with a pyrolysis gas in a fluidized bed reactor in a so-called product gas. Such a fluidized bed reactor comprises a region which adjoins an inlet and widens in the shape of a truncated cone and merges into a cylinder section provided with an outlet at the end. This body contains a fixed bed suspended in the inflow of a gasification agent, which is formed from coke from the previous pyrolysis process. This coke is kept in suspension in an elevated position by appropriate introduction and metering of a gasification agent, such as air, and is continuously converted or gasified into a product gas.

In the US 4,023,280 describes a fluid bed reactor in which coke is fed into the reactor from above and oxygen is introduced into the reactor from below via a nozzle.

GB 673,648 describes a method and an apparatus in which coke and gasification gas are mixed orthogonally with one another and are introduced together into a reduction reactor.

In a long-term operation of such systems, which is fundamentally desirable, a problem has emerged that in the floating bed reactor, in the course of the floating bed gasification, impurities in the form of, for example, stones, grains of sand, slag, nails, other metal parts or the like. accumulate. These contaminants are usually supplied unnoticed via the carbon-containing input material, since they are partially enclosed or enclosed by organic material, for example in mechanically shredded or shredded tree parts. Accumulations of impurities of the types mentioned above can reduce the efficiency of the system and, in the long run, even cause operational disruptions due to clumping or agglomeration lead, in particular, to blockages or mechanical damage within the floating bed reactor.

It is an object of the present invention to provide a method and a device for reliable and safe long-term operation of a fluidized bed reactor, which have a significantly reduced susceptibility to contaminants contained in carbon-containing input material.

This object is achieved by the features of a method according to the features of claim 1 and a device according to the features of claim 5. Further embodiments according to the invention are defined in the dependent claims.
The invention is based on the essential finding that impurities in the long term or with progressive conversion or gasification of the coke portion always have a higher density than a coke to be converted in the fluidized bed reactor. Thus, a device can be used in an adapted manner, which is known as a gravity or air classifier, in particular from grain mills, even if the chaff is to be discharged there and, if possible, only one flour body of a grain is to be further processed. It was therefore recognized as crucial that a layer which is designed as a fixed bed within the gasification reactor is lifted from an inlet area, that is to say in the full sense of the word actually "floats" on the gas flow, as is the case with floating bed gasification according to the disclosure of DE 10 2007 012 452 A1 the case is. Accordingly, a method according to the invention is characterized in that charred biomass is held in suspension in the inflow of the gasification agent as a fixed bed in the fluidized bed reactor and underneath this floating bed, contaminants essentially sink into an area against an inflow of gasification agent or are otherwise moved, in particular by gas flows be used to collect the contaminants and is designed accordingly. According to the invention, contaminants can essentially be removed continuously without any negative effect on the amount of gas produced, its quality or the overall efficiency of a system.

In other known methods, such as in the DE 10 2009 047 445 A1 or the WO 2010046222 A2 discloses, prepared bio-material to be reacted from below or at a lowest point in a gasification reactor with a mechanical device at the point where contaminants could settle and accumulate. In such methods, selective removal of contaminants in the manner described here is in principle not possible.

Advantageous further developments are the subject of the respective dependent claims. According to the invention, the gasification agent is introduced through a nozzle base into an inlet area below the reduction unit and from there carries coke to the reduction unit. Advantageously, the removal of impurities from an inlet area is carried out continuously in the sense that there is no interruption of an ongoing operation of the overall device. Accordingly, the above-mentioned space is used for the accumulation and also for the removal of accumulated impurities. In a preferred embodiment of the invention, the nozzle base is moved between at least two positions using a lifting means in order to remove collected contaminants in a targeted manner, in particular using a ramp into pressure-tight and lockable containers.

Preferably, with the nozzle base lowered or shifted for targeted removal of contaminants, an inflow of the gasification agent into the inlet area is largely shut off and a fixed bed in the fluidized bed reactor is then kept in suspension by a gasification agent introduced into the reduction unit via a nozzle unit.

A device for solving the above-mentioned object is characterized in that charred biomass is arranged in the inflow of the gasification agent as a fixed bed within the floating bed reactor of the levitation and a space for collecting contaminants is provided below the fixed bed. According to the invention To remove impurities from an inlet area, a gas-tight container or a container is provided below the fluidized bed reactor.

In a preferred embodiment of the invention, the container is separated from the inlet area by a baffle plate which only allows an opening for the entry of contaminants from the inlet area and in particular from a nozzle bottom into the container. An opening slot is preferably arranged behind the baffle plate, which is designed to discharge accumulated contaminants via a ramp into a container which can in particular be shut off separately.

In a special development of the invention, adjacent to the inlet area, a nozzle floor through which gasification agent can flow is provided, which can be moved between two positions by a lifting device or other drive means and in particular can be lowered, swiveled and / or rotated or in some other way, in particular for the targeted removal of accumulated contaminants Is designed to be displaceable.

Advantageously, a nozzle base is connected to slides and a drive means in such a way that, in the course of a displacement of the nozzle base, a supply of biomass is completed and at least one discharge for impurities is opened. A one-piece structural unit is preferably formed from a nozzle base, a slide as a closure for a biomass supply, and a closure for removing solid matter to a ramp through a further slide, and an opening or a hole for switching a solid, which is arranged in the direction of displacement for switching -Exit to the ramp. This arrangement results in a reduced travel distance Δh of this unit compared to a nozzle bottom alone. In addition, only one drive is required. In addition, there is an overall shortened design of the arrangement in this area. In a further development of the invention, the nozzle base adjoining the inlet region is subsequently inclined on one side for the gasification agent. The nozzle base is based on this feature to discharge collected impurities in an embodiment of the invention, as it were, inclined to a slide, the slide in a second position of the nozzle bottom being essentially aligned with a ramp which is connected to a collecting container.

It is further preferred that at least one of the above-mentioned containers has a fill level meter or a window for optical inspection and accordingly a filling of at least one of the containers is monitored by sensors.

Figur 1:

eine Schnittdarstellung eines Ausschnitts einer Reduktionseinheit gemäß eines ersten Ausführungsbeispiels der Erfindung;

Figur 2:

eine perspektivische Darstellung eines Ausführungsbeispiels einer Prallplatte gemäß dem Ausführungsbeispiel von Figur 1;

Figur 3:

eine Schnittdarstellung einer Reduktionseinheit gemäß einem zweiten Ausführungsbeispiel der Erfindung analog der Darstellung von Figur 1;

Figur 4:

eine Schnittdarstellung einer Reduktionseinheit gemäß einer Kombination einer leicht abgewandelten ersten und der zweiten Ausführungsform der Erfindung analog der Darstellung von Figur 1;

Figur 5:

eine Schnittdarstellung einer Reduktionseinheit gemäß einer Kombination der ersten und der zweiten Ausführungsform der Erfindung analog der Darstellung von Figur 1;

Figur 6:

eine Schnittdarstellung einer Reduktionseinheit gemäß einer dritten Ausführungsform der Erfindung als Variante der zweiten Ausführungsform analog der Darstellung von Figur 1;

Figur 7:

eine Schnittdarstellung einer vierten Ausführungsform der Erfindung analog der Darstellung von Figur 1;

Figuren 8a

bis 8e: eine dreidimensionale Ansicht einer zum Abführen angesammelter Störstoffe drehbaren Düsenplatte und weitere Ansichten,

Figur 9:

eine Variante des Ausführungsbeispiels von Figur 3 in einer Schnittdarstellung sowie

Figur 10a

und 10b: eine Schnittdarstellung einer seitlichen Ansicht sowie eine um 90° gedrehte Ansicht der Einheit aus Düsenboden und Schiebern des Ausführungsbeispiels von Figur 10 und

Figur 11:

eine Schnittdarstellung einer aus dem Stand der Technik bekannten Vorrichtung zur Schwebebett-Vergasung von Biomasse.

Further features and advantages of exemplary embodiments according to the invention are explained in more detail below with reference to an exemplary embodiment in comparison to a known device with reference to the drawing. In a schematic representation:

Figure 1:

a sectional view of a section of a reduction unit according to a first embodiment of the invention;

Figure 2:

a perspective view of an embodiment of a baffle plate according to the embodiment of Figure 1 ;

Figure 3:

3 shows a sectional illustration of a reduction unit according to a second exemplary embodiment of the invention, analogous to the illustration of FIG Figure 1 ;

Figure 4:

FIG. 2 shows a sectional illustration of a reduction unit according to a combination of a slightly modified first and second embodiment of the invention analogous to the illustration of FIG Figure 1 ;

Figure 5:

FIG. 2 shows a sectional illustration of a reduction unit according to a combination of the first and the second embodiment of the invention analogous to the illustration of FIG Figure 1 ;

Figure 6:

6 shows a sectional illustration of a reduction unit according to a third embodiment of the invention as a variant of the second embodiment analogous to the illustration of FIG Figure 1 ;

Figure 7:

a sectional view of a fourth embodiment of the invention analogous to the representation of Figure 1 ;

Figures 8a

to 8e: a three-dimensional view of a rotatable nozzle plate for discharging accumulated contaminants and further views,

Figure 9:

a variant of the embodiment of Figure 3 in a sectional view as well

Figure 10a

and FIG. 10b: a sectional illustration of a side view and a view rotated by 90 ° of the unit comprising the nozzle base and slides of the exemplary embodiment from FIG Figure 10 and

Figure 11:

a sectional view of a device known from the prior art for floating bed gasification of biomass.

The same reference numbers are always used for the same elements across the different illustrations.

The sketch of Figure 11 shows one from the DE 10 2007 012 452 A1 , to which reference is hereby made in its entirety, known device 1 for floating bed gasification of a carbon-containing material or of biomass as a complete system in a sectional view. The entire process path is shown here in connection with the supply of a biomass B, which is usually prepared by comminution and separation of foreign substances, into a pyrolysis unit 2 with gas nozzles 3, from there via an oxidation unit or transport route 4 with nozzle unit 5 until a product gas P emerges from a reduction unit 6, which here is provided with a nozzle unit 7 for introducing and metering gasification agent V.

As in the dashed line in Figure 11 All that is indicated below is only the reduction unit 6 as a fluidized bed reactor, especially since fluidized bed gasification of biomass with the supply of appropriately prepared biomass can also be carried out in a one-step process. For example, a recycling of dried sewage sludge in particular, due to its composition of predominantly carbon-containing material, could also be carried out without a pyrolysis unit 2. The same applies in principle to the recycling of externally produced coal or coke in accordance with the invention. It is therefore not absolutely necessary for the operation of a fluidized bed reactor that a supplied biomass is already largely charred, although only coke K will be referred to below. The problems of an accumulation of contaminants described at the beginning would also occur here in any case.

The processes within the reduction unit 6 are described below without further differentiation into one-stage, two-stage or multi-stage processes: Here, the reduction unit 6, in addition to the nozzle unit 7 for supplying gasification agent V, comprises an approximately frustoconically widening first section 8, which into a cylinder section 9 opens out, which runs out into an outlet 11 for product gas P via a section 10 which now tapers in the shape of a truncated cone. A normal degree of filling of the reduction unit 6 with a bed of coke pieces in the form of a fixed bed floating layer 12 shown hatched here is shown in FIG Figure 11 indicated. This level is monitored by a distance sensor 13 for measuring the level of the floating layer 12 made of coke pieces.

Like all known gasification systems, in particular fixed bed gasification systems in countercurrent or cocurrent operation, a device according to Figure 11 basically a non-contaminant Input material, i.e. very carbon-containing and as much as possible charred biomass without the addition of impurities S. This means, however, that the biomass B fed to the device 1 must first be freed of metal and other objects by means of separators and should also be sieved if possible to separate other impurities, such as sand or stones, that cannot be removed by a separator from the biomass. Otherwise, such impurities, which cannot be converted into product gas, enter the reduction unit 6. There the interfering substances S continue to accumulate, at least in the course of long-term operation of such a system, and ultimately lead to an interruption in the operation of the entire device 1 due to a reduction in efficiency.

The floating layer 12 builds up very quickly after starting up the device 1 described above in the reactor 12, as a result of which the entire system 1 then operates in a basically stable production mode. In the pyrolysis unit 2, biomass B is carbonized to a coke material K. This coke material K is then fed, for example via a screw conveyor, and is introduced into the reduction unit 6 via the inlet region 14 under the action of gaseous gasifying agent V. An entry of coke material K into the reduction unit 6 and the conversion of coke material K into the floating layer 12 are in equilibrium.

Due to the special mode of operation at the Figure 11 In the illustrated floating bed process, the fixed bed 12 is lifted from the inlet area 14 by the supply of the coke pieces from the pyrolysis reactor 2 within the first section 8 of the reduction unit 6 which widens in the shape of a truncated cone. As a result, a zone is formed below the fixed bed 12, in which impurities or slag, which are not carried along by the upward flow, collect against the direction of flow at the lowest point of the reduction unit 6. In upstream process stages, such as the initial loading of the device 1 with biomaterial B or the pyrolysis in the pyrolysis unit 2, the contaminants have no process-relevant disadvantages have been shown or they have not yet been present, in particular in the form of slags. Now there is a progressive accumulation of contaminants S in the inlet area 14 and thus at the lowest or lowest point of the reduction unit 6. In the long run, this cannot be counteracted sufficiently effectively by preparing products which are to be converted into product gas Biomass B or coke K additional measures are taken to separate out foreign substances which become contaminants in the reduction unit 6.

Exemplary embodiments of the present invention will now be described with reference to further figures, which in particular use the advantageous properties of a floating bed method outlined above to continuously carry away the removal of contaminants from an inlet area in the sense that there is no need to interrupt an ongoing operation of the overall device . A disturbance within the reduction unit 6, caused for example by a blockage, is excluded as far as technically possible. At the same time, a preparation of a biomass B that meets the above with reference to the illustration of Figure 11 Overall system 1 described is supplied, no stricter requirements, so that there are no additional costs. In addition, all of the exemplary embodiments described below can be retrofitted in existing plants or floating layer reduction units 6 and corresponding regulating and control methods can be expanded.

The illustration of Figure 1 shows a sectional view of a section of a reduction unit 6 around an inlet area 14 according to a first embodiment of the invention. The inlet area 14 is here compared to the representation of FIG Figure 11 have been modified in such a way that gasification agent V instead of through an annular nozzle unit 7, the gasification agent V now flows in via a connection 15 at the inlet area 14 parallel to a central axis M of the reduction unit 6 and counter to gravity.

The transport unit 4, via which new coke material K is supplied, is arranged at the inlet region 14, essentially perpendicular to the connection 15 for the gasification agent V. For this purpose, in this exemplary embodiment, a spiral or screw conveyor for metering according to requirements is to be supplied in previous sections of an overall system Figure 11 biomass K charred. Coming from the transport unit 4, the coke K is introduced into the reduction unit 6 in the inlet region 14 in the inflow of the gasification agent V essentially vertically and counter to gravity. In the first section 8 of the reduction unit 6, which widens approximately in the shape of a truncated cone, the coke particles are held in suspension as a fixed bed 12 and are progressively converted into product gas P. Within the reactor 6, the coke particles K thus float on the flow of the gasification agent V and are thus lifted off the inlet area 14 as a floating layer 12. Underneath this floating bed 12, a largely free space is created in which biomass particles K and charred carbon can move freely in the buoyancy of the inflowing gasification agent V against the counteracting weight force. In the long term or with progressive conversion or gasification of the coke portion, impurities S always have a higher density than a coke K to be converted in the fluidized bed reactor 6. Thus, over time, all the contaminants S entered into the fluidized bed reactor 6 against the gas flow V decrease in a lowest point. The contaminants S thus leave in accordance with the arrangement of Figure 1 the reduction unit 6 again and reenter the inlet area 14, where they are prevented from sinking further by a nozzle base 16. The accumulating impurities S then migrate over time from the nozzle base 16 into a container 17 which runs essentially perpendicular to the direction of the gas stream V as a space for the accumulation of impurities S.

An effective removal of contaminants S from the inlet area 14 takes place adjacent into a space designed as a gas-tight container or a container 17, as a result of which the use of a lock, which always represents a potential weak point in a device, is dispensed with can. The size of the container 17 is selected such that it should generally be emptied only every 100 operating hours, in particular in the course of an inspection of the entire system, which of course depends on the amount of the contaminants S contained in a carbon-containing starting product S.

In order to prevent coke K from collecting in the container 17 as much as possible, the container 17 is separated from the inlet area 14 by a baffle plate 18, which has only one opening 19 for the entry of contaminants S from the inlet area 14 and in particular from it from the nozzle bottom 16 into the container 17.

The container 17 is in the embodiment of FIG Figure 1 expanded beyond a suggested flange connection and constructed in several parts. The baffle plate 18 separates the container 17 from the inlet area 14 except for an opening 19 which runs approximately radially with respect to a subsequent pipe contour, behind which contaminants S collect. Figure 2 shows the baffle plate 18 in a perspective view as a section of the cylinder jacket of the inlet area 14, indicating the opening 19 which results in the installed position and which may be crescent-shaped. Furthermore, an opening slit 20 of a height b of approximately 20 mm, which is arranged behind the baffle plate 18 and can be seen in an installed position, can be seen, which for collecting contaminants S is discharged via a ramp 21 inclined at an angle α of approximately 30 ° to approximately 45 ° serves a lockable container 22, see Figure 1 . This entire container arrangement is pressure-tight. It is also connected to the inlet area 14 in a pressure-tight manner. By opening a shut-off means 23 embodied here in the form of a ball valve, the container 22 can be filled with accumulated contaminants S. After closing the ball valve 23, the container can be removed or emptied by opening and reconnected in a pressure-tight manner. In this way, very large quantities of contaminants S can be absorbed and / or the system described can be operated in continuous operation over a very long period of time without interference occurring due to the accumulation of contaminants S.

Figure 3 represents a section of a reduction unit 6 according to a second embodiment of the invention in section analogous to the illustration of FIG Figure 1 The basic functional principle remains the same, only the type, location and removal of accumulated contaminants S have been changed here for the discontinuous removal of accumulated contaminants S. In this exemplary embodiment, the nozzle base 16 adjoining the inlet region 14 in the connection 15 for the gasification agent V is inclined on one side by an angle β of approximately 10 ° to approximately 45 °, but gasification agent V continues to flow through it vertically from below. In a direction opposite to the inlet area 14, the connection 15 branches and leads via a ramp 25 into a container 26. This arrangement is also again pressure-tight. As in Figure 3 indicated, the nozzle base 16 can be moved between the described position and at least one second position by a lifting means 27 by a height Δh of about 30 cm here. In the second position, the nozzle base 16 is aligned with the ramp 25 in such a way that impurities S which have accumulated on the nozzle base 16 slide into the container 26 via the ramp 25. Analog of the embodiment of Figure 1 a ball valve 28 is provided here so that the container 26 could also be opened or removed for emptying. Common to both exemplary embodiments, however, is that contaminants S are continuously removed from the inlet area in the sense that there is no need to interrupt an ongoing operation of the overall device. Accordingly, the above-mentioned space 17, 26 is used for the accumulation and also for the discharge of accumulated impurities S.

A major advantage of this second exemplary embodiment compared to the first exemplary embodiment lies in the fact that here an entire cross-sectional width of the reactor pointing upwards is opened downwards and thus also impurities in the form of larger pieces can be removed, and this even while the process is running, due to the pressure-tight design Operation of the entire system. For this purpose, the nozzle base 16 is designed such that it can be changed in the vertical position without the supply of gasifying agent V having to be interrupted. By an oblique Arrangement of the nozzle base 16 makes it possible to "drain" accumulated contaminants S into the gas-tight container 26 when the nozzle base 16 is shut down, purely under the influence of gravity.

Figure 4 shows a sectional view of an arrangement according to a combination of a slightly modified first and the second embodiment of the invention analogous to the representations of the Figures 1 and 3rd . Experiments using a combination of contaminant collectors according to the first and the second exemplary embodiment have shown that the variant of FIG Figure 3 When comparatively "large" impurities S are removed, impurities in the form of ash accumulate behind an inner contour or the baffle plate 18, as the person skilled in the art usually only knows from combustion processes. However, continuous removal of such ash components also reduces the possibility of the formation of larger interfering bodies by agglomeration within the device described.

Accordingly, an arrangement is according to Figure 5 as a substantially pure combination of the first and the second exemplary embodiment of the invention analogous to the representation of FIG Figure 1 particularly suitable for separating both ash-like contaminants S and comparatively "large" contaminants S in larger quantities and removing them from the device in an uninterrupted long-term operation without the need to interrupt the operation.

A check of corresponding inspection openings or windows on the containers 17, 22, 26 can be included in the routine inspection process. According to an embodiment not shown in detail here, a filling of the container 17 and / or 22 and / or 26 is monitored by sensors. When a certain filling limit is reached, a corresponding message is then automatically sent to a plant operator.

Finally shows Figure 6 a sectional view of the section around the reduction unit 12 according to the embodiment of FIG figure 4th as a variant with features that can be applied in an adapted manner to all of the above exemplary embodiments:
As a first measure, a gas-permeable closure is provided in the transport section 4 from the oxidation unit, here indicated as a lowerable bulkhead 29 for safe retention of coke material K slipping from the transport section 4 into the inlet area 14. By closing this bulkhead 29, beyond any further termination of a supply of new coke material K by stopping, withdrawing and / or reverse conveyance of a screw conveyor in the transport path 4, any further supply of new coke material K into the inlet area 14 of the reduction unit 6 can be reliably excluded. This also ensures that no heavy and / or large piece of coke can be located in the region of the nozzle base 16 if accumulated contaminants S are to be removed by moving the nozzle base 16.

In addition to the blowing in of gasification agent V via the connection 15 at the inlet area 14, a nozzle unit 7 for introducing and metering gasification agent V1 directly into the reduction unit 6 is also provided. In this way, in particular in the case of removal of accumulated contaminants S with the nozzle base 16 lowered or shifted, at least one operation of the floating bed reactor 6 itself and an associated production of product gas P can be maintained without interruption even if the gasification agent V is blown in via the connection 15 into the Floating bed reactor 6 is temporarily interrupted or largely shut down. A sufficient amount of gasifying agent for a largely constant quality and amount of product gas P is then introduced as gasifying agent V1.

The illustration of Figure 7 shows a sectional view of a fourth embodiment of the invention analogous to the illustration of Figure 1 . This fourth embodiment of the invention provides an alternative to the embodiment according to Figure 3 shows that here now a displacement of the nozzle base 16 is no longer essentially parallel to the central axis M, but essentially perpendicular this is done by a displacement width Δb of approximately 125 mm here. An accumulation of interfering substances S located on the nozzle base 16 is caused by the amount of gravity against the inflow of gasification agent V on the shut-off means 23 as a result of the displacement caused by the lifting means 27 or due to a pivoting of the nozzle base 16 that runs essentially in one plane conveyed past into the gas-tight container 26 as the absolutely lowest point of this plant part. That already with reference to the illustration of Figure 6 described gas-permeable bulkhead 29 reliably prevents any coke K from slipping out of the transport unit 4 into the inlet area 14 during this process. A scraper AB, which is only indicated in terms of its position, can effectively support the removal or stripping of accumulated contaminant S from the nozzle base 16 in the course of the displacement movement. To form a scraper AB, an appropriately designed edge of the outer housing can suffice, especially since an inclined position of the nozzle base 16 is not absolutely necessary. With a displacement of the nozzle base 16, impurity S is removed in a simple manner by the stripper AB.

Finally the figure of Figure 8a a further variant, which is an adaptation of the embodiment of Figure 7 essentially only required in the dash-dotted area A: Within the adaptation area A, the nozzle base 16 is now part of a cylindrical body 30 which is now rotatably mounted in the area A with the connection 15 for gasifying agent V into the inlet area 14. In one position, the gasification agent V flows through the nozzle base 16, as already known. A curvature of the nozzle base 16 does not make any significant difference with regard to the function and accumulation of contaminants S compared to the preceding exemplary embodiments. If the cylindrical body 30 is now rotated by approximately 90 °, contaminants S collected on the nozzle base 16 fall through a continuous recess 31 and one Pipe section 32 into the container 26 arranged below. Figure 8a shows this cylindrical body 30 with a cylindrically continuous and closed recess 31 with the continuous tube section 32 adjoining it in three dimensions for the sake of clarity View with all hidden edges. The sequence of figures from Figure 8b to 8e shows a rear view through the cylindrical recess 31 in the direction of the curved nozzle base 16, followed by a representation of the body 30 which is tilted by 90 ° in relation to the first illustration, in which the continuous recess 31 is now connected to the inlet region 14 with a view through the pipe section 32 , where d denotes a diameter of the continuous recess 31 within the cylindrical body 30, which corresponds to a free cylindrical width in the area of the connection 15 and the inlet area 14 with a side view in FIG Figure 8d .. In the system described, this width d is approximately 115 mm, but it must be adapted to a particular system size to the extent evident to the person skilled in the art. See the secondary side view of the cylindrical body 30. In a last sketch is according to Figure 8e a plan view corresponding to the rear view of the curved nozzle bottom 16 is shown.

The embodiment of Figure 9 builds on that of Figure 3 and takes into account the possibility of blocking the coke entry, as in Figure 6 indicated. In this case, the ramp 25 for removing contaminant S is moved up to approximately the height of the transport route for the introduction of coke K. At the same time, the nozzle base 16 is integrated into a one-piece structural unit, here, for example, welded in as a plane at an angle to a central axis. The structural unit is designed to be displaceable overall as a hollow cylindrical section 33 in the cylindrical inlet region 14. The cylindrical section 33 further comprises a slide 34 as a closure for the supply of biomass K and a further slide 35 as a closure for the solids removal to the ramp 26. In the direction of displacement above the nozzle base 16 and below the slide 35, an opening 36 is provided as a hole in the cylindrical section 33. Through this opening 36, in the course of a displacement of the section 33 by an amount .DELTA.h, access to the ramp 26 for the removal of contaminant S from the nozzle plate 16 is opened, wherein at the same time any supply of biomass K is interrupted by the slide 34 as a closure. In principle, no biomass K reach the ramp 26 via the inlet area 14, or mix with impurity S in any other conceivable manner.

The side sectional view of the cylindrical portion 33 of Figure 10a illustrates how switching is effected by appropriate design of the slides 34, 35 and arrangement of the opening 36 in the direction of displacement, see also here Figure 10b in a side view rotated by 90 °. Compared to the embodiments of Figures 3 -6 a travel distance .DELTA.h of the nozzle plate 16 has been reduced and thus the overall design has been shortened. In addition, only one drive is used to close a supply of biomass K together with a displacement of the nozzle plate 16.

The orientation of the connections around the inlet area 14 can be modified in a manner that is obvious to a person skilled in the art, in order in particular to be able to meet space requirements. For example, with a view to the exemplary embodiment Figure 5 can be considered that when the branch with the ramp 25 is shifted, the two containers are combined to form a container which can then also be operated using only one closure means.

Reference list

1

contraption

2nd

Pyrolysis unit

3rd

Gas nozzles

4th

Oxidation unit with transport route / transport unit

5

Nozzle unit

6

Reduction unit / fluidized bed reactor

7

Nozzle unit for introducing and metering gasification agent V into the reduction unit 6

8th

first section of the reduction unit 6 that widens approximately in the shape of a truncated cone

9

Cylinder section of the reduction unit 6

10th

conical section 10 of the reduction unit 6

11

Outlet of the reduction unit 6

12th

Fixed bed / bed of coke pieces in the form of a floating layer

13

Distance sensor / level measurement

14

Inlet area into the reduction unit 6

15

Connection for the gasification agent V at the inlet area 14

16

Nozzle bottom

17th

Container / container / space for the accumulation of contaminants S

18th

Baffle plate

19th

approximately radial opening of the baffle plate 18

20

Opening slot

21

ramp

22

lockable container

23

Shut-off device / ball valve

24th

-

25th

ramp

26

container

27

Lifting equipment

28

-

29

gas permeable bulkhead

30th

cylindrical body

31

continuous recess

32

Pipe piece, to the continuous recess 31 then

33

hollow cylindrical section

34

Slider as a closure for the supply of biomass K

35

Slider as a closure of the solids removal to the ramp 26

36

opening

A

Adaptation area at connection 15 for the gasification agent V

B

Biomass

M

Central axis

K

Coke particles

P

Product gas

S

Contaminant

T-

inner edge on a housing as a wiper for the nozzle bottom 16

V

Gasifying agent

V1

additional gasifying agent

b

Height of the opening slot 20

Δh

Lifting height of the lifting means 27

Δb

Displacement

FROM

Wipers

d

Diameter through recess 31 in the cylindrical. Body 30

α

Ramp angle 21, 25

β

Angle of inclination of the nozzle base 16

Claims (12)

1. Method for removing impurities (S) from a gasifier for substances containing carbon in form of a floating bed reactor (6) in which biomass and/or coke (K) in a feed stream of a gaseous gasification means (V) is converted into a product gas (P), wherein
   the biomass and/or coke (K) in the feed stream of the gasification means (V) is suspended floatingly as a fixed bed (12) in the floating bed reactor (6),
   characterized in that
   the gasification means (V) is introduced through a nozzle bottom (16) into an intake portion (14) below the floating bed reactor (6) and takes the biomass and/or coke (K) into the floating bed reactor (6) therefrom, and
   below the floating bed (12), impurities (S) which are contained in the biomass and/or coke and which have a higher density than the biomass and/or coke, sink or are moved substantially against the feed stream of the gasification means (V) into a space (17) used for collecting the impurities (S),
   wherein for removing the impurities (S) from an intake portion (14) a gastight vessel or a container (17, 22, 26) is provided adjacent thereto.
2. The method according to the preceding claim, characterized in that the nozzle bottom (16) is moved between at least two positions by using a lifting means (27) or another driving means, in order to removed collected impurities (S) intentionally, particularly by using a ramp (21, 25) into pressure-tight and closeable containers (22, 26).
3. The method according to the preceding claim, characterized in that, when the nozzle bottom (16) is lowered, rotated or displaced for intentionally removing collected impurities (S), a feed stream of the gasification means (V) is largely switched off and a fixed bed (12) in the floating bed reactor (6) is suspended floatingly by means of a gasification means (V1) introduced via a nozzle unit (7) into the floating bed ractor (6).
4. The method according to any one of the preceding claims characterized in that the filling of at least one of the containers (17, 22, 26) is monitored by a sensor.
5. Device for removing impurities from a gasifier for substances containing carbon configured for applying the method according to any one of the preceding claims, wherein
   the biomass and/or coke (K) is suspended floatingly as fixed bed (12) within the floating bed reactor (6) in the feed stream of the gasification means (V) and
   the gasification means (V) is introduced through a nozzle bottom (16) into an intake portion (14) below the floating bed reactor (6) and takes the biomass and/or coke (K) into the floating bed reactor (6) therefrom, and
   that, for removing the impurities (S) from an intake portion (14), a gastight vessel or container (17) is provided adjacent thereto for collecting the impurities (S) contained in the biomass and/or coke and having a higher density than the biomass and/or coke.
6. The device according to the preceding claim, characterized in that the container (17) is separated from the intake portion (14) by means of a baffle plate (18) having only one opening (19) for the impurities (S) to enter the space or container (17) from the intake portion (14) and particularly from the nozzle bottom (16).
7. The device according to the preceding claim, characterized in that an opening slot (20) is arranged behind the baffle plate (18), the opening slot being configured for deducing collected impurities (S) via a ramp (21) into a particularly separate closable container.
8. The device according to any one of claims 5-7, characterized in that the nozzle bottom (16) can be moved, displaced, lowered and/or rotated between two positions.
9. The device according to the preceding claim, characterized in that the nozzle bottom (16) is a part of a rotatable cylindrical body (30) comprising, particularly in a second position, a through-going recess (31).
10. The device according to any one of the preceding claims 5-9, characterized in that the nozzle bottom (16) adjoining the intake portion (14) is formed at least on one side in a tilted manner by an angle (β) at the connection (15) for the gasification means (V).
11. The device according to the preceding claim, characterized in that the nozzle bottom (16) is inclined like a slide for deducing collected impurities (S), wherein, in a second position of the nozzle bottom (16), the slide substantially flushes with a ramp (25) having an angle (a) and the ramp (25) is particularly connected to a collecting container (26).
12. The device according to any one of the preceding claims 5-11, characterized in that at least one of the containers (17, 22, 26) comprises a filling level sensor for monitoring the filling level particularly by a sensor or a window for optical inspection.

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