Fixed bed gasifier with rollers
Patent Information
- Application Number
- EP2023712334
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-16
- Filing Date
- 2023-03-02
- Publication Date
- 2025-01-22
Smart Images
Figure 1.1
Abstract
Description
[0001] Fixed bed gasifier with rollers
[0002] Description
[0003] Technical area
[0004] The present disclosure relates to a fixed-bed gasifier for generating a product or synthesis gas from solid fuel, in particular from slag-forming fuel, comprising a gasifier vessel, in particular a cylindrical one. The gasifier vessel has a fuel supply for supplying a solid fuel, a gasification agent supply for supplying a gasification agent used to gasify the solid fuel contained in the vessel, and an outlet for removing slag and ash, product gas, and synthesis gas produced during the gasification of the solid fuel.
[0005] In a fixed-bed gasifier, (loose) fuel, especially biomass, in a solid state (solid fuel), typically wood or coal, sewage sludge, but also biomass-like and other secondary fuels, as well as domestic waste / plastic fractions, is thermo-chemically converted into a combustible product or synthesis gas (fuel gas) with the aid of a gasification or oxidizing agent, especially air, oxygen, carbon dioxide, or steam. Through gasification in a fixed-bed gasifier, the solid fuel can be converted into a gaseous secondary fuel or product gas, which can be used, for example, in electricity generation or as a fuel (fuel gas), or as synthesis gas for chemical synthesis.
[0006] The fixed bed gasifier or gasifier vessel is divided vertically or axially into different, adjacent temperature zones. The temperature zone closest to the opening is a drying zone, in which the water contained in the solid fuel is evaporated at a drying temperature. Vertically below the drying zone there is a pyrolysis zone. In the pyrolysis zone the solid fuel is decomposed at a pyrolysis temperature. Vertically below the pyrolysis zone there is an oxidation zone. In the oxidation zone the carbon (C) and hydrogen (H) contained in the decomposed solid fuel are oxidized at an oxidation temperature to form carbon dioxide (CO2) and water (H2O) respectively. Vertically below the oxidation zone there is a reduction zone. In the reduction zone the carbon dioxide (CO2) and hydrogen (H) obtained from the oxidation zone are oxidizedThe water (H2O) is reduced at a reduction temperature to the combustible product or synthesis gas produced by fixed-bed gasification. In the fixed-bed gasifier, the drying temperature is lower than the pyrolysis temperature, which in turn is lower than the oxidation temperature, which in turn is higher than the reduction temperature. Carbonaceous ash remains as a permanent component of the gasified solid fuel.
[0007] Furthermore, fixed-bed gasifiers can be used to gasify slag-forming fuels or biomass, especially biological residues, preferably waste, and more preferably sewage sludge, as fuel. The gasification of such slag-forming fuels, especially sewage sludge, serves the environmentally friendly disposal of these materials.
[0008] In fixed-bed gasification, especially in cases where slag-forming fuels, such as waste, are used as the biomass to be gasified, the slag and carbonaceous ash produced during gasification as gasification residue are particularly difficult to remove from the fixed-bed gasifier. In conventional fixed-bed gasifiers, a horizontally arranged grate is provided as a support device below the outlet of the gasification vessel within the fixed-bed gasifier. This is known, for example, from DE 10 2019 218 310 A1. The slag and ash emerging from the gasification vessel are fed via the grate-shaped support device to an ash and gas outlet, through which the gasification residues and the gas generated during gasification can leave the fixed-bed gasifier.However, the slag sometimes forms clumps, and the grate-shaped support device may therefore be unable to transport the slag and ash evenly out of the gasification vessel. This can lead to slag and possibly ash accumulating on the grate, thereby impairing gasification in the fixed-bed gasifier or even causing it to stop completely.
[0009] Against this background, two counter-rotating rollers were proposed as a support device in DE 10 2019 218 310 A1. However, the problem with this is that the rollers acting as a support device may push the gasification residues, especially slag, back into the gasification vessel. This severely impairs gasification in the gasification vessel.
[0010] Accordingly, it is an object of the present disclosure to provide a fixed-bed gasifier that solves the problem described above. In particular, a fixed-bed gasifier is to be provided in which reliable gasification is ensured. Preferably, a fixed-bed gasifier is to be provided in which gasification residues, in particular slag and carbonaceous ash, are uniformly conveyed from the fixed-bed gasifier, and a backflow of the gasification residues into the gasifier vessel is prevented.
[0011] The problem underlying the disclosure is solved by a fixed bed gasifier according to claim 1.
[0012] Accordingly, the present disclosure relates to a fixed-bed gasifier for generating a product or synthesis gas from solid fuels, in particular from slag-forming fuels, comprising a gasifier vessel, in particular a cylindrical one. The gasifier vessel has a fuel supply for supplying a solid fuel, one or more gasification agent supplies, in particular exactly two gasification agent supplies, for supplying one or more gasification agents which serve to gasify the solid fuel contained in the vessel, and an outlet for removing slag, carbon-containing ash, and product and synthesis gas which are produced during the gasification of the solid fuel. Below or downstream of the gasifier vessel orAt least two rollers are arranged at the outlet of the gasifier vessel for conveying residues remaining during the gasification of the fuel, in particular carbonaceous ash and slag, from the fixed-bed gasifier, which rollers rotate, preferably intermittently, in opposite directions about their longitudinal roller axes, wherein the axial distance between the two longitudinal roller axes is at least as large as the width or the diameter of the outlet of the gasifier vessel.
[0013] With the help of the counter-rotating rollers, the gasification residues can be removed from the gasification vessel or the fixed-bed gasifier particularly effectively and residue-free. Because the rollers rotate in opposite directions, a particularly large amount of material can be extracted from the fixed-bed gasifier. If the center distance between the two rollers' longitudinal axes is at least as large as the diameter, preferably the inner diameter, of the gasification vessel (outlet), it can be ensured that the material column (of ash and slag) is removed from the gasification vessel (downward) by the rollers and not pushed back (upward) into the gasification vessel.
[0014] Advantageous aspects of the present disclosure are the subject of the dependent claims and are explained in more detail below.
[0015] More preferably, the rollers rotate inwards, i.e. towards each other, and away from the outlet of the carburetor container, as viewed from the side of the outlet of the carburetor container.
[0016] With this direction of rotation of the rollers, it is particularly effective to prevent gasification residues from being pushed back into the carburetor container by the rollers.
[0017] In particular, the rollers are arranged axially symmetrically to a central longitudinal axis of the gasification vessel. This allows the gasification residues to be conveyed particularly evenly and effectively. Furthermore, it is particularly advantageous if the rollers' longitudinal axes are arranged horizontally and also perpendicular to the longitudinal axis of the gasification vessel. This allows the rollers to convey slag particularly effectively.
[0018] This allows for a uniform material discharge from the gasification vessel outlet. This ensures homogeneous material distribution throughout the bed up to the gasification residue discharge point. Thus, the discharged material only shifts toward the center of the gasification vessel, where it is then discharged from the fixed-bed gasifier via the outlet, and does not accumulate in one spot. This also prevents the discharged material from shifting toward the gasification vessel (upward). Fine and large particles of the gasification residue are conveyed or discharged in proportion to the roller speed. This supports trouble-free continuous operation of the fixed-bed gasifier and good product gas quality.
[0019] Advantageously, the rollers are mounted on hollow shafts in which a coolant, in particular water or oil, is guided to cool the rollers.
[0020] This hollow shaft cooling system allows the rollers to be sufficiently cooled. Cooling the rollers is necessary to prevent the rollers or elements mounted on them from bending due to the heat transferred to them by the slag and ash. The coal produced as a residue during gasification, which forms a layer around the rollers, acts as a poor heat conductor and acts as an insulator against the slag, which can reach temperatures of up to 1000°C and hits the rollers. Therefore, cooling the rollers via the hollow shafts is sufficient despite the high temperatures of the gasification residues.
[0021] The rollers can be cooled via evaporative cooling or via conductive water or oil cooling. With evaporative cooling, as with water or oil cooling, a liquid is guided in the hollow shafts of the rollers. With water or oil cooling, as well as evaporative cooling, the coolant heats up as it flows through the hollow shafts. The heated water is then carried away, along with the heat generated at the rollers. With evaporative cooling, hot steam, which is created due to the high temperature of the heated liquid coolant, in particular water, is also carried away from the coolant, in particular pumped out. The steam (without soot particles) is guided upwards (towards the carburetor container) and cools down in the process. The cooling system, in which the coolant is carried and circulates, is a closed system that is not fluidly connected to the carburetor.A coolant reservoir containing coolant is located above the rollers, ensuring natural circulation.
[0022] In this way, the rollers can be cooled effectively and without much effort.
[0023] It is also advantageous if the rollers, and in particular teeth arranged on the rollers, and / or discs of the rollers having the teeth, are made of hardened steel, in particular Hardox.
[0024] This material does not deform despite the heat to which the rollers are exposed and can also conduct sufficient heat from the outer circumference of the rollers, which is mainly in contact with the hot gasification residues, to the centrally arranged hollow shafts.
[0025] It is also conceivable that the rollers each have a plurality of circular disc-shaped roller disks that are connected to one another in a rotationally fixed manner, and that some of the roller disks are provided with teeth on their outer circumference that mesh with the teeth of the counter-rotating roller.
[0026] The number of roller discs can be easily varied, allowing rollers of different lengths to be easily provided thanks to the modular roller design. The teeth of the counter-rotating rollers mesh with each other, allowing the material to be removed from the gasification vessel and thus from the fixed-bed gasifier to be conveyed particularly effectively. The roller teeth advantageously crush slag lumps, allowing them to be easily conveyed. The aforementioned hollow shaft cooling prevents the teeth from bending due to high temperatures.
[0027] In particular, it can be provided that teeth of a first tooth size are distributed over the outer circumference of the roller discs alternately with teeth of a second tooth size, which is different from the first tooth size.
[0028] Due to the different tooth sizes of the rollers, slag lumps can be captured and crushed particularly effectively and thus transported by the rollers out of the gasification vessel or fixed bed gasification.
[0029] Furthermore, it is conceivable that the teeth of the first tooth size of one roller mesh with the teeth of the first tooth size of the roller rotating in the opposite direction to one roller and that the teeth of the second tooth size of one roller mesh with the teeth of the second tooth size of the roller rotating in the opposite direction to one roller.
[0030] Between the teeth of the first tooth size, which are larger than the teeth of the second tooth size, smaller slag lumps can be captured and crushed than between the (smaller) teeth of the second tooth size. This ensures that slag lumps of different sizes can be effectively captured and crushed by the roller teeth.
[0031] It is also useful if the roller discs are divided into roller discs with teeth and smooth roller discs without teeth and the roller discs with teeth are arranged one behind the other in the longitudinal direction of the roller, alternating with smooth roller discs.
[0032] Rollers in which only every second roller disc is provided with teeth are cheaper to manufacture and easier to clean than rollers in which all roller discs are provided with teeth.
[0033] Advantageously, the toothed roller discs are larger in size or overall diameter than the smooth roller discs by the number of teeth. A preferred aspect relates to the smooth roller discs of a roller each contacting the roller discs with teeth of the counter-rotating roller, and the teeth of the counter-rotating rollers mesh with each other in the longitudinal direction of the roller.
[0034] In this way, the teeth of one roller can remove gasification residues from the smooth roller discs of the other, counter-rotating roller. In this way, the two counter-rotating rollers clean each other (automatically).
[0035] It is also advantageous if the teeth on the rollers are arranged in a spiral or helical manner relative to the longitudinal axis of the rollers. This ensures that only one pair of teeth meshes with each other at a time. This advantageously minimizes the drive power for the rollers and the load on the roller bearings, and thus on the hollow shafts.
[0036] The problem is also solved by a fixed-bed gasifier with the features of the independent claim. In the fixed-bed gasifier of the same generic type, the rollers each have a plurality of circular disk-shaped roller discs that are connected to one another in a rotationally fixed manner. The roller discs are divided into roller discs with teeth and smooth roller discs without teeth, and the roller discs with teeth are arranged one behind the other in the longitudinal direction of the rollers, alternating with smooth roller discs. The smooth roller discs of one roller are each opposite the roller discs with teeth of another (adjacent) counter-rotating roller, and vice versa. In this way, the teeth of one roller can remove gasification residues from the smooth roller discs of the other, counter-rotating roller.In this way, the two counter-rotating rollers clean each other (automatically), and gasification residues, especially slag and ash, are evenly discharged from the fixed-bed gasifier. It is also conceivable for two counter-rotating rollers to form a roller pair, and for the fixed-bed gasifier to have more than one roller pair, especially two roller pairs.
[0037] If the fixed-bed gasifier has more than one pair of rollers, a particularly large volume of gasification residues can be extracted from the gasifier vessel or from the fixed-bed gasifier. Accordingly, more feedstock (fuel) can be gasified in the gasifier vessel.
[0038] Short description of the characters
[0039] Fig. 1 is a schematic longitudinal sectional view of a fixed bed gasifier;
[0040] Fig. 2 is a schematic longitudinal sectional view of a carburetor insert;
[0041] Fig. 3 is a schematic plan view of two rollers;
[0042] Fig. 4 is a schematic longitudinal sectional view of two rollers arranged side by side; and
[0043] Fig. 5 is a simplified schematic longitudinal sectional view of a fixed bed gasifier with more than two rollers.
[0044] Description of aspects of the present disclosure
[0045] Aspects of the present disclosure are described below based on the accompanying figures. The aspects presented are merely exemplary and may be combined with one another where technically feasible.
[0046] Fig. 1 is a schematic longitudinal sectional view of a fixed-bed gasifier F. The fixed-bed gasifier F described below is particularly suitable for the gasification of slag-forming solid fuels, in particular waste, e.g. sewage sludge. The fixed-bed gasifier F has a gasifier vessel VB. The gasifier vessel VB has, in its uppermost section viewed in the axial direction or height direction H, a fuel feed 1 as well as a main gasification agent feed 2a and a secondary gasification agent feed 2b. The (solid) fuel to be gasified, in particular slag-forming fuel, is fed to the gasifier vessel VB via the fuel feed 1. A gasification agent, such as air, oxygen, water vapor or carbon dioxide, is fed to the gasifier vessel VB of the fixed-bed gasifier F via the gasification agent feeds 2a, 2b.The gasification vessel VB has a chute 3, to the uppermost section of which, in a vertical direction H, the fuel supply 1 and the gasification agent supply lines 2a, 2b are connected. The chute 3 opens with its lowermost section into a, in particular, pressure-tight, gasification casing 4. The chute 3 is hollow-cylindrical.
[0047] The main gasification agent feed 2a is used in every operating mode of the fixed-bed gasifier F. The secondary gasification agent feed 2b is used when the system is operated with oxygen and water vapor / carbon dioxide. The pressure-tight gasifier shell 4 is essentially hollow-cylindrical. On its upper side (topmost side of the gasifier shell 4 in the vertical direction H), the gasifier shell 4 has an opening 5 through which the downcomer 3 is connected to the gasifier shell 4. The upper part of the fixed-bed gasifier F, i.e., the downcomer 3 with fuel feed 1 and main gasification agent feed 2a as well as secondary gasification agent feed 2b, forms a flange 5 and is flange-mounted to the gasifier shell 4.The flange connection between the upper part of the fixed bed gasifier F and the gasifier jacket 4 is sealed gas-tight to the environment so that no gas can escape from the fixed bed gasifier F between the upper part of the fixed bed gasifier F and the gasifier jacket 4.
[0048] In the gasification vessel VB, which extends into the gasification shell 4, successive, different temperature zones 6 to 9 are present within the gasification shell 4 in the height direction H. The uppermost temperature zone viewed in the height direction H of the fixed bed gasifier F is the drying zone 6. At a drying temperature of approximately 100°C, the water contained in the fuel is evaporated here. Below this is the pyrolysis zone 7, in which the fuel is decomposed at a pyrolysis temperature of up to 250°C. Below the pyrolysis zone 7 is the oxidation zone 8, in which the carbon and hydrogen present in the fuel are oxidized to carbon dioxide and water at an oxidation temperature of up to 1700°C (see above).Below oxidation zone 8 is reduction zone 9, the lowest section of the gasification vessel VB. In this zone, the carbon dioxide and water obtained in oxidation zone 6 are reduced at a reduction temperature between 600°C and 800°C. After reduction, the finished product, namely a product or synthesis gas, is obtained.
[0049] Carbonaceous ash and slag remain as solid residues from the gasification in temperature zones 6 to 9 in the fixed-bed gasifier F. These are discharged into the gasifier shell 4 via an outlet on the gasifier vessel VB (lowest section of the gasifier vessel VB in the vertical direction H), which is arranged within the gasifier shell 4. In order to remove these solid residues from the gasifier shell 4 and to guarantee homogeneous bed conditions in the gasifier shell 4, the solid residues are conveyed into an ash and gas outlet 11 by means of at least two counter-rotating rollers 10 (described in more detail with reference to Fig. 3 to Fig. 5), which are arranged in a lower section of the gasifier shell 4 (viewed in the vertical direction H). The gasifier shell 4 tapers conically towards the ash and gas outlet 11. The solid residues and the product gas obtained from the fixed bed gasifier F are removed via the ash and gas outlet 11.
[0050] The section of the carburetor vessel VB in which temperature zones 6 to 9 are present is designed here as a carburetor insert 12 formed separately from the downcomer 3. The carburetor insert 12 is arranged within the carburetor casing 4 and extends in the vertical direction H. The carburetor insert 12, like the downcomer 3, has a hollow cylindrical shape. The diameter, in particular the inner diameter, of the carburetor insert 12 advantageously corresponds to the diameter, preferably the inner diameter, of the downcomer 3. The carburetor insert 12 limits the diameter of temperature zones 6 to 9 to its own inner diameter. The side of the carburetor insert 12 facing a central longitudinal axis M of the carburetor vessel VB, which forms at least a section of the vessel wall of the carburetor vessel VB, is referred to as the inner casing 13. The inner casing 13 is advantageously made of stainless steel.Together with an outer shell 14, which is spaced parallel from the inner shell 13, the inner shell 13 encloses a temperature homogenization layer 15. The outer shell 14 is advantageously also made of (stable) stainless steel. In particular, copper is used as the temperature homogenization layer 15. The copper ensures that the temperature is optimally distributed homogeneously in the vertical direction H and in the circumferential direction of the carburetor vessel VB.
[0051] The carburetor insert 12, in particular its uppermost section in the vertical direction H, is connected to the downcomer 3, in particular to its lowermost section in the vertical direction H, by means of a holder 16. The holder 16 is a type of flange that is flange-mounted to the carburetor insert. An insulating plate can be attached as a seal for the two flanges. This insulating plate thermally insulates the carburetor insert 12 from the downcomer 3. Furthermore, a temperature-insulating layer 17 is provided between the outer casing 14 and the inner wall of the carburetor casing 4. The temperature-insulating layer 17 reinforces the temperature-homogenizing or even temperature-distributing effect inherent in the carburetor insert 12, thus reducing or even preventing temperature gradients within the carburetor container VB or the carburetor insert 12.The temperature insulation layer 17 is hollow cylindrical and surrounds the carburetor insert 12 from the outside.
[0052] Fig. 2 is a schematic longitudinal sectional view of the gasifier insert 12. It is clearly visible how the temperature homogenization layer 15 is enclosed or encompassed by the inner shell 13 and the outer shell 14. The temperature homogenization layer 15 can, under certain circumstances, melt or liquefy at very high temperatures (from approximately 1085°C for copper). Since temperatures of up to 1700°C occur in the fixed-bed gasifier F, the copper can melt. Enclosing the temperature homogenization layer 15 by the inner shell 13 and outer shell 14 prevents the temperature homogenization layer 15 from "flowing away."
[0053] Fig. 3 is a schematic plan view of two intermeshing rollers 10 arranged in the gasifier shell 4, in particular directly below the outlet of the gasifier vessel VB. With the help of the rollers 10, fine and coarse ash or slag particles are conveyed axially symmetrically and proportionally to a roller speed. The rollers 10 thus support trouble-free continuous operation of the fixed-bed gasifier F and good gas quality (gas with little or no contaminants). The center distance AA between the two longitudinal axes W of the rollers 10 corresponds at least to the diameter DM of the gasifier insert 12.
[0054] The rollers 10 consist of a plurality of annular roller discs 18,
[0055] 19. The annular roller discs 18, 19 are arranged one behind the other along the roller's longitudinal axis W and are connected to each other in a rotationally fixed or integral manner. Roller discs 18 with a smooth outer circumference alternate with roller discs 19 with teeth distributed over their outer circumference.
[0056] 20. The roller discs 19 with teeth 20 are larger in diameter by the number of teeth 20 than the smooth roller discs 18. The smooth or toothless roller discs 18 of a roller 10 each contact the roller discs 19 with teeth 20 of the other roller 10 arranged next to it. In this way, the two adjacent rollers 10 clean each other. At least one tooth 20 meshes with the corresponding tooth 20 of the adjacent roller 10 in the longitudinal direction of the roller.
[0057] Fig. 4, like Fig. 1, shows a longitudinal sectional view of two intermeshing and counter-rotating rollers 10, which rotate relative to each other at the top (carburettor insert side) and thus form a roller pair. The arrow D in the respective roller 10 indicates their direction of rotation. It can be seen that the rollers 10 rotate relative to each other. In doing so, the rollers 10 rotate away from the outlet of the gasification vessel VB (see Fig. 1). The teeth 20 of the interacting rollers 10 of a roller pair engage and mesh with one another. As a result, the teeth 20 grasp and crush lumpy slag. The teeth 20 of a roller disk 19 differ in size and are divided into teeth 20 and smaller teeth 20, which are smaller than the teeth 20. The teeth 20 and the smaller teeth 20 alternate over the outer circumference of the respective roller disc 19.The rollers 10 are arranged and aligned with one another in such a way that a tooth 20 of one roller 10 meshes or interacts with a tooth 20 of the other roller 10 of the roller pair arranged next to it, and a smaller tooth 20 of one roller 10 meshes or interacts with a smaller tooth 20 of the other roller 10 of the roller pair arranged next to it. In particular, the longitudinal shaft axes W of the two adjacent rollers 10, 10 are parallel to one another. In addition, the teeth 20 on the roller disks 19 are arranged spirally or helically with respect to the respective roller longitudinal axis W. This ensures that only one pair of teeth 20 of the roller pair is in engagement at any one time. Advantageously, this minimizes the drive power for the rollers 10 and the load on a roller bearing.
[0058] Furthermore, the rollers 10 can reach very high temperatures, as the ash and slag they convey have temperatures of up to 1000°C. Cooling of the rollers 10 is therefore necessary. Accordingly, the rollers 10 are arranged on hollow shafts 21 for cooling. A coolant, in particular water or oil, flows through the hollow shafts 21 to cool the rollers 10. Thanks to this type of cooling, inexpensive or simple seals and bearings, in particular radial shaft seals, can be used in the fixed-bed gasifier F. Advantageously, the coolant flowing past the hot rollers 10 and thus heated can be used to dry the solid fuel. It is particularly useful to dry the solid fuel outside the fixed-bed gasifier F using the heat from the heated coolant.
[0059] The fixed bed gasifier F can be scaled taking into account the ratio of the roller center distance to the inner diameter of the gasifier insert 12. Fig. 5 is a simplified schematic longitudinal sectional view of the fixed bed gasifier F with four rollers 10 arranged next to one another. For simplicity, only the gasifier insert 12 is shown here, as well as the temperature zones 6 to 9 occurring within the gasifier insert 12. Four rollers 10 are arranged below the gasifier insert 12 at a height in the vertical direction H. The center distance of the two outermost rollers 10 corresponds at least to the inner diameter of the gasifier insert 12. Each roller 10 rotates in the opposite direction to the roller(s) 10 arranged next to it. The outer rollers 10 and the inner rollers 10 arranged directly next to it each form a roller pair.In the event that more than one pair of rollers is provided in the fixed-bed gasifier F, the rollers 10 are smaller and have a greater distance from the oxidation zone 8 or the reduction zone 9 than in a fixed-bed gasifier F that only has one pair of rollers. In this way, even a fixed-bed gasifier F with more than one pair of rollers can convey the (carbon-containing) ash and slag produced during gasification from the gasifier vessel VB, or convey this material downwards towards the outlet. The rollers 10 of one pair of rollers rotate towards each other. The inner rollers 10 of the respective different pairs of rollers rotate away from each other. The rollers 10 are constructed as shown in Figures 3 and 4 and arranged such that the roller discs 18 without teeth of one roller are opposite the roller discs 19 with teeth of another (adjacent) counter-rotating roller, and vice versa.
[0060] List of reference symbols
[0061] I Fuel supply
[0062] 2a Main gasification agent supply
[0063] 2b Secondary gasification agent supply
[0064] 3 Drop shaft
[0065] 4 carburetor casing
[0066] 5 Opening
[0067] 6 drying zone
[0068] 7 Pyrolysis zone
[0069] 8 Oxidation zone
[0070] 9 Reduction zone
[0071] 10 rollers
[0072] II Ash and gas extraction
[0073] 12 Carburettor insert
[0074] 13 Inner jacket
[0075] 14 Outer jacket
[0076] 15 Temperature homogenization layer
[0077] 16 Bracket
[0078] 17 Temperature insulation layer
[0079] 18 smooth roller disc
[0080] 19 Roller disc with teeth
[0081] 20 teeth
[0082] 21 Hollow shaft
[0083] AA Center distance of the rollers
[0084] D Direction of rotation of roller
[0085] DM Diameter of the carburetor tank outlet
[0086] F fixed-bed gasifier
[0087] H Altitude direction
[0088] M center axis carburetor tank
[0089] R Radial direction
[0090] VB carburetor tank
[0091] W longitudinal axis of the roll
Claims
Claims 1. Fixed-bed gasifier (F) for producing product or synthesis gas from solid fuel, in particular from slag-forming fuel, comprising a gasifier vessel (VB), in particular a cylindrical one, which has: a fuel feed (1) for supplying a solid fuel, at least one gasification agent feed (2a, 2b) for supplying at least one gasification agent which serves to gasify the solid fuel located in the vessel (VB), and an outlet for discharging slag and product and synthesis gas which are produced during the gasification of the solid fuel, and at least two rollers (10) arranged below or downstream of the gasifier vessel (VB) and rotating in opposite directions about their longitudinal axis (W) for conveying residues remaining during the gasification of the fuel, in particular carbonaceous ash and slag, from the fixed-bed gasifier (F), wherein the rollers (10) themselves directly convey the residues.characterized in that the rollers (10) interlock and the axial distance between the two roller longitudinal axes (W) is at least as large as the width or diameter of the outlet of the carburetor container (VB).
2. Fixed bed carburetor (F) according to claim 1 , characterized in that the rollers (10) are mounted over hollow shafts (21) in which a coolant, in particular water or oil, is guided for cooling the rollers (10).
3. Fixed bed carburetor (F) according to claim 1 or 2, characterized in that the rollers (10) are made of hardened steel, in particular of Hardox.
4. Fixed bed carburetor (F) according to one of claims 1 to 3, characterized in that the rollers (10) each have a plurality of circular disk-shaped roller discs (18, 19) connected to each other in a rotationally fixed manner and some of the roller discs (18, 19) are provided on their outer circumference with teeth (20) which mesh with the teeth (20) of the counter-rotating roller (10).
5. Fixed bed carburetor (F) according to claim 4, characterized in that teeth (20) of a first tooth size are distributed alternately with teeth (20) of a second tooth size, which is different from the first tooth size, over the outer circumference of the roller disks (18, 19).
6. Fixed bed carburetor (F) according to claim 5, characterized in that the teeth (20) of the first tooth size of a roller (10) mesh with the teeth (20) of the first tooth size of the roller (10) rotating in the opposite direction to the first roller (10) and the teeth (20) of the second tooth size of a roller (10) mesh with the teeth (20) of the second tooth size of the roller (10) rotating in the opposite direction to the first roller (10).
7. Fixed bed carburetor (F) according to one of claims 4 to 6, characterized in that the roller discs (18, 19) are divided into roller discs (19) with teeth (20) and smooth roller discs (18) without teeth (20) and the roller discs (18) with teeth (20) are arranged alternately with smooth roller discs (18) in the longitudinal direction of the rollers.
8. Fixed bed carburetor (F) according to claim 7, characterized in that the smooth roller discs (18) of a roller (10) are opposite the roller discs (19) with teeth (20) of the counter-rotating roller (10) and vice versa.
9. Fixed bed carburetor (F) according to one of claims 4 to 8, characterized in that the teeth (20) of the rollers (10) are arranged in a spiral shape with respect to the longitudinal axis (W) of the rollers.
10. Fixed-bed gasifier (F) for producing a product or synthesis gas from solid fuel, in particular from slag-forming fuel, with a gasifier container (VB), in particular cylindrical, which has: a fuel feed (1 ) for supplying a solid fuel, at least one gasification agent feed (2a, 2b) for supplying at least one gasification agent which serves to gasify the solid fuel located in the container (VB), and an outlet for removing slag and product and synthesis gas which are produced during the gasification of the solid fuel, and at least two rollers (10) arranged below or downstream of the gasifier container (VB) and rotating in opposite directions about their longitudinal axis (W) for conveying residues remaining during the gasification of the fuel, in particular ash and slag, from the fixed bed gasifier (F), characterized in that the rollers (10) each have a plurality of circular disk-shaped roller discs (18, 19) which are connected to each other in a rotationally fixed manner;the roller discs (18, 19) are divided into roller discs (19) with teeth (20) and smooth roller discs (18) without teeth (20), and the roller discs (18) with teeth (20) are arranged alternately with smooth roller discs (18) in the longitudinal direction of the rollers; and the smooth roller discs (18) of one roller (10) are each opposite the roller discs (19) with teeth (20) of another counter-rotating roller (10) and vice versa.