NO814387L - METHOD AND APPARATUS FOR CONTINUOUS PRODUCTION OF FUEL GAS FROM ORGANIC WASTE MATERIALS - Google Patents

Description

This invention relates to a method for the continuous production of fuel gas from organic waste materials, where the waste in a continuous flow of material is first dried under air shut-off at temperatures that rise approximately to 550°C

and degassed and then gasified at higher temperatures. The invention relates to two alternative methods for carrying out the process as well as devices for carrying out these alternative methods.

Methods and devices for gasification of waste materials from organic substances, i.e. particularly solid and possibly liquid waste materials, belong to the state of the art. It is e.g. known from German patent document 26 54 041 a method where waste materials are first dried and then degassed and finally gasified. In such a known method, however, the thus pretreated, gaseous and solid products are incinerated after the treatment.

Drying, degassing, gasification and combustion processes then take place continuously. The degassing products that enter the gasification chamber are then formed into a glowing bed to which a sufficient amount of air is supplied so that the bed will have a sufficient volume and possibly a sufficiently high temperature. However, gasification gases produced by this method do not have such a uniform composition that it pays to transport them to a consumer in another location.

From German offtl. document 27 34 973 is a method known where the heated waste materials after drying, i.e. during gasification, are supplied with fresh air in a sub-stoichiometric ratio, namely before introduction into the combustion chamber. Some of the combustible gases formed during the gasification of the waste are then diverted before entering the combustion chamber. In this case too, gas is not produced with the necessary uniformity that could be transported to a consumer.

Production of fuel gas from wood, coal or coke is previously known. The fuel gas is produced by incomplete combustion of the material in a shaft furnace-like generator which is supplied with air, oxygen and/or water vapor as a gasification medium.

As combustible gas components, the produced generator gas essentially contains carbon monoxide and hydrogen as well as smaller amounts of methane. The other gas components in the generator gas are nitrogen and carbon dioxide. The gas production process proceeds endothermically. Efforts are made to carry out the generator gas formation at the highest possible temperature to obtain large proportions of carbon monoxide and hydrogen.

In the case of continuous material withdrawal from the generator, it is known to introduce the gasifier from below into the shaft furnace. The generated generator gas is taken out at the top of the shaft furnace and must first be tarred before it can be used as fuel gas.

The task of the invention is therefore to provide a method or methods which allow, by gasification of organic waste, to produce fuel gas with a uniform composition which is suitable for external use and which can be produced continuously.' With a view to the different types of waste materials, which are available and which, during continuous operation, also often enter a heterogeneous material flow, the production of the fuel gas must be easily regulated and result in a good degree of efficiency. It is also a task for the invention to provide technically the simplest possible devices for carrying out the method.

A solution (patent claim 1) of the task consists in the degassed material for gasification of the same, which takes place at temperatures of up to approximately 1000°C, at the latest at the beginning of the gasification phase, certain amounts of gasification media such as air, steam, C02, 02 or a mixture of these media, where the amounts correspond to the changes in the composition of the material during the material movement. In so far as the invention represents a continuation of the known methods, as the gasification media are supplied to the materials to be gasified from the beginning during the gasification process in direct current. Thereby it is achieved that the gasification process is much easier to master or control than hitherto, because the addition of gasification agents depending on the composition of the gases formed during the gasification and of the solid, combustible materials can be controlled in a simple way.

One. alternative solution (patent claim 2) consists in drying, degassing and gasification of waste material being carried out in two procedurally separate steps, with the waste materials being dried and degassed in the first step and the material formed during the degassing being gasified in the second step, and where the materials are conveyed' so that the material flow between the first and the second process stage, which aims to mechanically process the material formed during degassing, is interruptible and that for gasification of. the degassed material, which occurs at temperatures up to approx. 1000°C, at the beginning of the gasification phase, corresponding amounts of gasification agents, such as air, steam, CC>2, 0~ or a mixture of these media, are added in accordance with changes in the composition of the material in the material stream.

It is very advantageous that gasification medium is supplied to the material to be gasified in the material's flow direction with gases formed during drying and degassing (patent claim 3). Thereby, the steam released during drying is led to the formation of water gas for gasification of coal and the distillation gases formed during degassing of the waste to crack the long-chain hydrocarbon molecules into low-molecular compounds at gasification temperature above the coke formed during degassing, and in this way the waste materials are reacted with a not inconsiderable part to high-quality compounds. In this connection, it is appropriate for air and/or oxygen to be added to the glow bed formed by gasification to crack the dry distillation gases (patent claim 4).

It is appropriate that the gasification medium is added depending on the temperature in the glow bed which is formed during the gasification (patent claim 5).

Preferably, the gasification medium is introduced into a zone in the material to be gasified, where the temperature is approximately 200°C (patent claim 6).

It is advantageous that. the fuel gas formed during the gasification is taken out through or over a gap-shaped passage, the material being held above the gap until gasification (patent claim 7). It is also advantageous that the fuel gas formed in recuperative heat exchange serves to preheat the material to be gasified (patent claim 8).

When gasifying fine-grained material, e.g. gasification of sawdust or rice husk, it has been shown to be advantageous for the formation of the glow bed to add at least 10% by weight of coarse material (patent claim 9). As a result of the different piece sizes of the material to be processed, a glow bed area consisting of coarser parts is formed in the removal slot, which acts like a sieve and only allows through sufficiently small material parts that are largely gassed to the ash outlet. The dimensions of the coarse material pieces are chosen so that the material transport in the shaft is not disturbed.

The fuel gas taken out of the glow bed is passed over another layer of ash at the bottom of the shaft furnace, where a post-reaction takes place with the remaining carbon (patent claim 10).

An appropriate continuation of the alternative method is that non-combustible components such as metal bodies which are bound to the waste by organic substances are removed after the degassing from the material stream of the materials to be processed further (patent claim 11). This also results in a better position of the process steps during gasification.

For carrying out the method in accordance with "the first solution, a shaft furnace is provided with a coating device or feeding device arranged on the top of the furnace with a device for releasing heat for drying and degassing the material located in the upper part of the shaft as well as a device for releasing of heat for gasification of material located in the lower part of the shaft, and where an outlet for the ash is arranged at the bottom of the shaft furnace. Such a device is known, for example, from German patent 26 54 041. According to the inventive solution, this device is equipped as follows ( patent claim 12) that in the lower part of the shaft there is arranged a supply for gasification medium which is to be added to the degassed material for gasification of the same, at such a distance above the passage located at the lower end of the shaft that the gasification media reaches the degassed material at the beginning of the gasification phase and that the gasification space is separated from the subsequent 'space by means of a g bypass with a narrowing cross-section for the passage of the non-combustible residues remaining after the gasification, and that immediately below this bypass there is an outlet for the fuel gas. The passage is then advantageously designed as an annular gap or longitudinal gap (patent claim 13).

In an advantageous way, the flow rate for gasification medium can be adjusted with a regulator arranged in the supply in accordance with the reaction temperature in the glow bed and controlled (patent claim 14). The glow bed is supported by one conically designed outlet device which is arranged on the ash outlet of the shaft furnace and centrally in the shaft. The outlet device is rotatably stored and is cooled to avoid overheating of the material. At the lower edge of the outlet device, there is arranged as a passage an outlet gap, the gap width of which is determined depending on the piece-like form of the material that forms in the glow bed and in accordance with the necessary mass transport during turnover. The gap width is determined so that the residence time of the material to be gasified in the annealing bed is sufficient for extensive gasification of the material before it is removed from the annealing bed. The conical shape of the outlet device supports the smooth transport of material to the outlet slot. By turning the withdrawal device, the amount of material withdrawal can be regulated.

A fuel gas line is connected to the shaft furnace's ash outlet to remove the fuel gas produced in the shaft furnace. The gas formed in the loose material layer is thus taken out immediately by the annealing bed formed in the shaft furnace. The fuel gas contains only small proportions of oil and tar. The gas flows through the fuel gas line, preferably in a recuperative heat exchanger, which serves to preheat the materials to be gasified in the shaft furnace (patent claim 15).

For cooling the outlet device, the gasification medium that flows into the bulk layer is preferably used (patent claim 16). Appropriately, the supply of the gasification medium takes place through the outlet device and exits centrally in the shaft (patent claim 17). A largely homogeneous reaction zone in the shaft furnace for the production of fuel gas is achieved in connection with the central supply of the gasification medium by the fact that the outlet gap is designed as an annular gap between the lower edge of the outlet device and the shaft furnace wall (patent claim 18). The gasification medium flows through the reaction zone in the shaft furnace from the inside out.

The extraction of the highly gasified material through . the conical outlet device is affected by the angle of inclination of the cone surface. The angle of inclination between the base surface of the outlet device and the cone surface must not exceed 30 degrees and preferably amounts to 20 degrees (patent claim 19). For the transport of material that is taken out, guide ribs are arranged on the cone surface facing the annealing bed (patent claim 20). When the outlet device is turned, the material in the glow bed is guided by the guide ribs towards the outlet slot.

One or more vanes are also attached to the outlet device which project to the bottom of the shaft furnace and which, when turning

the outlet device transports the ash that collects on the bottom of the shaft furnace to the ash outlet (patent claim 21). Fuel gas flowing out of the glow bed is drawn over the after-glow ash for post-reaction with the residual carbon.

According to a further appropriate embodiment of the shaft furnace, the bulk material layer above the mouth for supplying the gasification medium has such a height that the flow resistance from the loose material layer above the supply is greater than the flow resistance in the supply for the gasification medium (patent claim 22). This is particularly advantageous when the gasification medium is introduced into the loose material layer by creating a negative pressure at the mouth for the supply of air. The stronger flow resistance in the loose material layer above the mouth also prevents the penetration of side air over the loose material layer into the reaction zone, even in the event that the shaft furnace is open to the atmosphere for filling in material to be gasified. In order to regulate the amount of gasification medium to be introduced into the bulk layer, the supply for gasification medium has a flow regulator which is controlled in dependence on the temperature in the annealing bed (patent claim 23).

In order to be able to use the shaft furnace for materials of the most diverse structure and with different gasification characteristics, the outlet device in the shaft furnace is preferably arranged to be replaceable (patent claim 24). Depending on the material to be gasified, take-out devices that are specially adapted to the different material properties can be inserted into the furnace.

The alternative method is preferably carried out using a device with a shaft furnace which has a device for releasing heat for gasification of the material located in the shaft, and where an outlet for the ash is arranged in or at the bottom of the shaft furnace. In terms of invention, in the device with the shaft furnace, a first chamber is arranged for pre-treatment of the waste from organic substances by heat action during air shut-off at temperatures up to approximately 550°C, where the shaft is connected as another chamber serving by heat action on the materials at a higher temperature, where at the upper part of the shaft opens into a feed for gasifier which is to be supplied with material to be gasified into the gasification space, and where the shaft is separated from the subsequent space by a passage with a narrowing cross-section for passage of the following

■non-combustible residues remaining after the gasification, and where an exhaust for the fuel gas is arranged immediately below the passage located at the lower end of the shaft (patent claim 25). In the lower part of the shaft furnace, a shut-off flap is suitably arranged during the supply. The passage is advantageously designed as an annular slit or longitudinal slit (patent claim 26).

An appropriate embodiment of the invention for the shaft furnace consists in exhaust gas ducts being connected to the shaft which in its course surrounds the outer wall of the first chamber (patent claim 27).

In the inventive design of the device with the shaft furnace, material to be gasified is supplied to the specified gasification media in direct current just at the beginning of the gasification process. This enables a dosage corresponding to the composition of the gases formed during gasification and the solid, combustible substances that pass through the gasification chamber. This enables ongoing adaptation to the ever-changing conditions through appropriate management.

By separating the drying and degassing zone (first chamber) from the gasification zone (second, chamber or shaft), two temperature ranges have been obtained. In the drying and degassing zone, temperatures reach a maximum of 500°C and in the gasification zone the temperatures are at approx. 800°C (possibly up to 1000°C), i.e. that only the gasification zone must be made of temperature-resistant materials, while simpler materials available on the market are sufficient for making the first chamber.

By separating the drying and degassing process from the gasification process, it is further achieved that the processes are even easier to control with a view to achieving quality-wise uniform fuel gas in the gasification step for use outside the process plant. Moreover, an increase in the processing capacity of the device according to the invention is achieved in relation to what is achieved with comparable, previously known devices.

A preferred embodiment of the device with the shaft furnace according to the invention consists in that the first chamber, which is designed for pre-treatment of the waste by drying and degassing, is designed as a rotary drum lying at an angle in relation to the horizontal with a gas-tight sluice system at the coating end, and whose other end opens at the upper part of the shaft which forms the gasification chamber, so that material which is subjected to heat treatment after being discharged from the rotary drum enters the furnace shaft (patent claim 28).

If, in this embodiment of the device with the shaft furnace, a shaft furnace of the same size as before is used, this leads to an increase of the processing capacity in relation to the shaft furnace that was used in the execution of the method according to the first solution, by a factor of five. The situation is such that when using a device according to the invention consisting of only the shaft furnace, a certain furnace cross-section must not be exceeded, because then, as a result of the poor thermal conductivity of the waste, it is no longer possible to evenly supply the necessary energy required for drying, degassing and gasification. In the case of indirect heat supply and from the oven walls, but also in the case of direct heat supply, reaction channels and edge overflows can then form. Therefore, turnover cannot usually exceed 1 tonne per year. hour if only a shaft furnace is used and it is assumed that the process will run flawlessly.

When using the device with a shaft furnace to implement the alternative solution, the significant volume reduction takes place in the rotary drum. It is further advantageous that the shaft furnace is predominantly supplied with coke, whereby a loose mass quality is achieved which is much more gas permeable compared to ordinary rubbish, so that the gasification media which are supplied in direct current at the inlet to the shaft, causes a smooth, uniform and complete gasification.

From the journal "Mull und Abfall" pages 293-300 (see especially table 2 as well as the left-hand column page 296) it is previously known to use a steel rotary drum for pyrolysis of organic waste substances. This known rotary drum is heated indirectly with exhaust gas heat from a gas engine or with the exhaust gases from a gas and/or oil burner. On both sides of the rotatable ion drum, there are gas-tight sluice systems that allow a continuous coating and a continuous removal of residual materials. Pipe fittings serve for heat introduction and material turnover and material transport. With this known device, however, the separation between drying and degassing from before the gassing is not provided for. The production of a gas of equal and uniform nature and energy content, the transport of which can be carried out economically to a point of consumption, is only possible to a lesser extent.

In order to achieve the simplest possible transition between the rotary drum and the shaft furnace, it is appropriate to design the device with the shaft furnace according to the invention so that between the end of the rotary drum, which is intended for passing on material that has been subjected to drying and degassing, and the shaft, an intermediate chamber that can be shut off from above is arranged which projects over the upper part of the shaft and which can be closed from the external environment by means of one or more gas-tight locks (patent claim 29).

In order to achieve that the constituents associated with organic waste substances are removed from the material flow with substances to be processed further, i.e. that they are not enclosed in the gasification zone in an uncontrolled manner, is. it is advantageous to design the device with the shaft furnace according to the invention so that the upper part of the shaft is completely or partially covered with a vibrating screen and that a shaft for the discharge of non-combustible material which can be shut off with a gas-tight lock also has its lower surface at a height of the shaking screen or vibrating screen opens into the upper part of the shaft on the side opposite the opening of the rotary drum (patent claim 30).

The invention will be explained in more detail using three examples of the device for producing fuel gas from organic substances. Reference is made to the drawings, where: Fig. 1 schematically shows a device for gasification of waste materials of organic substances for carrying out the first method according to the invention. - The device is shown schematically in section. Fig. 2 also shows in section and strongly schematically produced a further device for gasification of waste from organic substances for carrying out the first method according to the invention, and

fig. 3 illustrates an example of the device for carrying out the second method according to the invention. Here, too, the plant is shown in section.

As can be seen from fig. 1, waste of organic substances is fed through a filling sluice 1 which is arranged on a pipe connection 2 which leads to a shaft furnace 4. In the upper part of the shaft, the waste is heated to approximately 550°C and thereby dried and degassed. To achieve this, the drying and degassing zone can be heated. The heating can either take place directly by arranging burners, only one of which is shown in the drawing, or can also take place by the fuel gas withdrawn through the exhaust line 11 being led along a channel section 3 which surrounds the drying and degassing zone.. Furthermore, a burner 8 for direct heating be arranged at the upper entrance to the shaft furnace 4. If necessary, both heating options can be used simultaneously. For the drying and degassing room, according to the design in fig. 1 without transition connected to a gasification chamber 6. The gasification chamber is separated from the furnace's lower chamber by means of one or more sluice elements 7. A supply line 5 for gasification medium opens into the upper part of the gasification chamber 6. As a gasification medium, part of the fuel gas can be used which is taken out from the exhaust line 11. The lock elements 7 have a closed upper side and are stored on a shaft. When the shaft is turned, the sluice openings, which are designed as longitudinal slits, are opened and solid and gaseous products from the gasification chamber 6 can then be sluiced out to the underlying chamber. The exhaust line 11 opens into the mentioned lower space below the locks 7 and serves to carry away the fuel gas which is formed during the gasification and which has entered the space below the gasification space 6. Non-combustible components that enter the space below the gasification space 6 are likely to start with a closing flap 10. The advantage of this closing flap is that it is thereby easier to achieve complete diversion of the ash that is formed during the gasification and which eventually falls into the ash extraction room 12.

Fig. 2 shows a shaft furnace 4 which can be fed with organic material to be gasified, especially organic waste. The material is fed into a hopper and transported with a screw conveyor 13 to the shaft furnace's material inlet 14. In the shaft furnace's interior, the introduced material forms a loose mass layer 15. As a result of gravity, the material moves downwards in the furnace. The material is heated in the upper area of the shaft furnace in a preheating zone A by means of a recuperative heat exchanger 16. According to the design example, the heat exchanger 16 is formed in the simplest possible way by a double-walled pipe that surrounds the upper part of the shaft furnace and thus forms a space through which the the fuel gas formed in the shaft furnace which flows through the space in countercurrent to the flow direction of the material in the shaft furnace. In the pre-heating zone A, the material to be heated is dried in heat exchange with the fuel gas and heated to approx. 200°C.

A rotatably mounted withdrawal device 17 is introduced from below into the shaft furnace 4 and supports the annealing bed 18 which is formed in the lower area of the loose mass layer 15. The withdrawal device 17 is arranged centrally in the shaft and tapers conically towards the loose mass layer 15. At the lower edge of the cone or cone there is a withdrawal gap 19 which is designed as an annular gap between the edge of the cone and the shaft furnace wall 20. The width of the gap is determined depending on the piece size of the material formed in the annealing bed 18 and in accordance with the desired material turnover. For gasification of fine material, e.g. rice husk etc., it has proven appropriate to have a gap width between the edge of the cone and the wall of the shaft furnace of approximately 3 to 5 mm. When gasifying fine-grained material, at least 10% by weight is added

coarse material. The piece size for the coarse material is chosen so that bridging in the shaft is avoided. As a result of different piece sizes of the material, the glow layer 18 forms a sieve-like structure, so that only sufficiently small parts of the material which have been largely degassed are removed through the outlet slot 19.

Centrally through the outlet device 17 is a supply device 21 for gasification medium which empties into the loose mass layer 15 above the glow layer 18. The gasification medium that flows through the outlet device 17 acts as a coolant and prevents overheating of the material. At the same time, the gasification medium is heated before entering the loose mass layer. A covering device 22 at the end of the supply device 21 prevents penetration of loose material into the supply line. The outlet device 17 and the supply device 21 form a unit. Through the supply device 21, the zone of the loose mass layer is supplied.

23 the gasification medium and the material to be gasified, in this zone, after the heat exchange with the fuel gas, has a temperature

at approximately 200°C. The gasification medium flows together with the water vapor formed during the drying of the material to be gasified as well as with the other gases formed in the bulk layer in the material's

direction of flow in a reaction zone B through the loose mass layer and during formation of fuel gas through the glow layer. A fuel gas line 24 for removing the fuel gas is connected to the furnace at the furnace's ash outlet 25. The fuel gas is removed, according to the example, by suction from the glow bed using a suction device not shown in the drawing. The fuel gas flows through the heat exchanger 16 and is cooled there while giving off heat to the loose mass layer.

The maximum temperature in the glow layer 18 is preferably set to a temperature in the range between 900 and 1000°C.

A temperature sensor 26, which is introduced into the loose mass layer, measures

a reference temperature in the shaft furnace above the annealing layer 18, which changes analogously with the reaction temperature in the annealing layer. The temperature sensor 26 is in functional connection with a through-flow regulator 27 which, according to the example, is inserted in the supply device 21 for the gasification medium. The flow of the gasification medium in the supply device 21 can, however, also be regulated in another way, e.g. by changing the suction underpressure in the fuel gas line 24 or by a combination using the recirculating flow regulator 27 and by setting the underpressure at the ash outlet 25. When the desired temperature in the glow layer is exceeded, the supply of gasification medium is throttled, while when the temperature drops, the inflow of air or oxygen is increased. The temperature of the glow layer can also be regulated using the composition of the gasification medium. With metered addition of air, oxygen, water vapor or carbon dioxide, safe and fast effective control of the gasification process is achieved as a result of the immediate supply of gasification medium to the loose mass layer above the glow layer.

The outlet device 17 has cone surfaces 28 which, according to the example, form an inclination angle of 20 degrees with the -base-surface of the cone, as shown at 29- in the drawing. When gasifying fine material, it has been shown that with such an inclination of the cone surfaces, even material transport and removal of material from the glow layer is achieved without unwanted densification of the material and, with the same uniformity along the outlet gap. On the cone floats 28 there are guide ribs 30 which, when the outlet cone is rotated, lead the material in the glow layer to the outlet slot 19; According to the example, the withdrawal device is moved in steps by means of a drive wind device 31.

The gasified material falls through the outlet slot 19 onto an ash layer 32 which forms on the bottom of the shaft furnace below the outlet device 17. The fuel gas that flows out of the glow layer is led for after-reaction of residual carbon over the ash layer 32 and flows to the ash outlet 25. On the outlet device 17 is attached vanes 33 which project down to the bottom of the shaft furnace and which, by turning the outlet device 17, transport the ash to the ash outlet 25.

In the case of a shaft furnace which is equipped with a screw conveyor for feeding in material as explained above, the shaft has been left upside down to simplify the material supply. However, in order to prevent side air from entering the open shaft and penetrating through the loose mass layer into the reaction zone, the height of the loose mass layer in the shaft furnace is dimensioned so that the flow resistance in the loose mass layer above the mouth for the supply of gasification medium is greater than the flow resistance in the supply device. The supply device is open to the atmosphere. Air is used as the gasification medium, which is sucked into the furnace's loose mass layer.

In a shaft oven of the type mentioned above with a diameter of 260 mm and a shaft height of 1 m, the rice husk was mixed with coarser wood particles. The size of the wood particles was a maximum of approximately 10 mm. 20% by weight of wood particles were added to the rice husks. As a minimum value, 10% by weight has been shown to be beneficial. The introduced material was preheated in the shaft furnace's preheating zone B in heat exchange with the generator gas to approximately 200°C. Air was supplied to the loose mass layer as a gasification agent. In reaction zone B, the loose mass layer was approximately 350 mm long (high?). The highest temperature in the glow layer was 900 to 1000°C. The withdrawal device was rotated step by step with a time period of approx. 2 minutes, so that it performed 2 to 3 revolutions per hour.

With a turnover of 12 to 15 kg of the material to be gasified per hour, 30 to 40 m<3> of fuel gas could be produced per hour.

Another shaft furnace with a diameter of 400 mm and a height of 1.5 m was used for gasification of sawdust which was also mixed with wood. particles before entering the furnace. The wood particles were of different sizes up to wood chips with a size of 150 mm in length. The reaction zone in this shaft furnace was 450 mm long (high), the maximum temperature in the annealing layer was 900 to 1000 C and the outlet device performed 1 to 2 full revolutions per minute. hour during stepwise movement. The step period or time period was approximately 4 minutes. With a turnover of 30 to 40 kg of material to be gasified per hour, approx. lOOm<3> fuel gas per hour.

In addition, the shaft furnace was operated with good results with the following waste materials: sawdust, planer shavings, cocoa husks, chopped tree bark, chopped straw, chopped household waste, pelletized household waste, algae.

On average, the fuel gas produced in the shaft furnace had the following composition: 2 vol.% CH^, 15 vol.% H2, 25 vol.% CO, 5 vol.% , 53 vol.? N2. The heating value of the fuel gas was in the range from 5000 to 6000 kJ/m<3>.

The gasification process can be set optimally by controlling the supply of gasification medium and regulation of material withdrawal. For different materials, different cone shapes and gap widths are adapted in the outlet device as well as the reaction zone. In one and the same shaft furnace, materials with the most different structures and different gasification properties can be processed and processed to produce fuel gas, preferably by simple replacement of the outlet device.

At the one in fig. 3 shows the embodiment of the device according to the invention, the waste material is first moved through the filling sluice 1 which is arranged at one end of a rotary drum 34 arranged at an angle in relation to the vertical, into the mentioned drum. Lock 1 is gas tight. switchable. In the drum 34, the waste is heated to approximately 550°C and thereby dried and degassed. The rotary drum 34 is therefore heatable and heating can take place either directly by arranging one or more burners 8, one of which is shown in the drawing, or by connecting an exhaust line 11 below the gasification chamber 6 to the shaft furnace 4 for it by gasification formed combustible gas which is led so that the gas is carried around the rotary drum 34, with the exhaust gas line 11 entering a mantle which, together with the drum, forms an annular space 3 through which the fuel gas flows. If appropriate, both firing methods can be used. The drain end of the drum 34 is connected through an intermediate comb 35 to the upper part of the shaft furnace 4, so that the material introduced into the rotary drum 34 after drying and degassing is sluiced into the shaft of the furnace 4. The material dried and degassed in the rotary drum 34 is thus first passed through the intermediate chamber 35 which can be closed off gas-tight by means of sluices 36 and 37 and which is in connection with and lies above the upper part of the shaft. The upper part of the shaft furnace 4 is covered with a shaking sieve or vibration layer 38. The advantage of this design is that only such products enter the gasification chamber 6 that can pass the meshes in the sieve 38. coked materials formed during degassing. The other non-combustible waste components, such as metal bodies, are passed over the vibrating screen 38 to a shaft 39 which is connected to the intermediate chamber 35 and can be sealed gas-tight by means of a sluice 37 and can be led away from there. Additives that may be necessary for the binding of harmful substances that may form during heat treatment of waste are added in this version of the device through the sluice 36 arranged at the intermediate chamber 35. The upper part of the shaft furnace 4 forms it by of a burner 9 heatable gasification space 6, at the upper end of which there is an inlet for a supply line 5 for gasification medium. The gasification chamber 6 is separated by an annular gap from the underlying chamber, as can be seen from fig. 3. A tubular part 40 projects from above into the furnace shaft and carries at its lower end a cone-shaped part 41. The annular gap is formed between the lower edge of the cone 41 and the adjacent wall of the furnace shaft. Of course, such a narrowing can also be produced in another way. The tubular part 40 can be rotatably arranged about its longitudinal axis, and in such a case it can be appropriate to arrange stirrer arms projecting laterally into the shaft (not shown in the drawing) which loosen the material to be gasified when the pipe part '40 is turned.

The devices shown in the drawings can also be used for the processing or treatment of other waste substances, e.g. used car tyres, plastic waste, carpet waste, organic waste from the wood industry and forestry as well as other special organic waste suitable for the production of fuel gas. The gasification then takes place particularly evenly and completely when it in fig. The device shown in 3 is used.

Claims (30)

1. Process for the continuous production of fuel gas from organic waste materials, where the waste, in a continuous material flow, is first dried and degassed at temperatures rising to 550°C and then gasified at higher temperatures, characterized in that at the latest at the beginning of the gasification phase, it is added degassed material for gasification of the same, which gasification takes place at temperatures of approximately 1000°C, amounts of gasification medium corresponding to the changes in the composition of the material during the material flow movement, which medium comprises air, steam, , C>2 or a mixture of these. 2. Procedure for the continuous production of fuel gas from organic waste materials, which in continuous material- current first'during air shutdown is dried and degassed at temperatures that rise to approx. 550°C and then gassed at higher temperatures, characterized in that drying, degassing and gassing of the waste material is carried out in two procedurally separate steps, the waste material being dried and degassed in the first step and the material formed by degassing gassed in the second step, where the material is fed so that the material flow can be interrupted between the first and second process steps to achieve mechanical treatment of the material formed by degassing, and that the degassed material is used for gasification of the same, which occurs at temperatures up to approximately 1000°C , are added at the beginning of the gasification phase gasification quantities that correspond to the changes in composition of the material during the material flow movement, where the gasification medium comprises e.g. air, steam, CC^ , 0 2 or a mixture of_these materials. 3. Method according to claim 1 or 2, characterized in that the gasification medium is supplied to the material to be gasified in the flow direction of the material together with the gas formed during drying and degassing. 4. Method according to claim 3, characterized in that air and/or oxygen is added to the glowing layer formed during the gasification for cracking the distillation gases. 5. Method according to one of claims 1 to 4, characterized in that the gasification medium is added depending on the temperature that occurs in the glow layer formed during gasification. 6. Method according to one of claims 1 to 5, characterized in that the gasification medium is introduced into a zone in the material to be gasified, where there is a temperature of approximately 200°C. 7. Method according to one of claims 1 to 6, characterized in that the fuel gas developed during the gasification is removed through a gap-shaped passage, where the material above the gap is held until it gasifies. 8. Method according to one of claims 1 to 7, characterized in that the fuel gas formed in recuperative heat exchange serves to preheat the material to be gasified. 9. Method according to one of the preceding claims, characterized in that at least 10% by weight of coarse material is added to fine-grained material for gasification thereof. 10. Method according to one of the preceding claims, characterized in that the fuel gas formed during the gasification and flowing away from the glow layer is led over an ash layer removed from the glow layer to the ash outlet. 11. Method according to claim 2, characterized in that non-combustible components, such as metal bodies, are removed after degassing from the material stream to be processed further. 12. Shaft furnace for carrying out the method according to claim 1 with a filling device arranged at the top of the shaft, with a device for emitting heat for drying and degassing the material located in the upper part of the shaft as well as a device for release of heat for gasification of the material located in the lower part of the shaft, where an outlet for ash is arranged at the bottom of the shaft furnace, characterized in that a supply device (5,21) for gasification medium to be added to the degassed material for gasification of the same , is arranged at such a distance above the passage (7,17) located at the lower end of the shaft that the gasification medium reaches the degassed material at the beginning of the gasification phase, and that the gasification space is separated from the subsequent space by a passage with a narrowing cross-section for passage of the non-combustible residues remaining after the gasification, and that an exhaust (11) for the fuel gas is arranged immediately below the passage. 13.. Shaft furnace according to claim 12, characterized in that the passage is designed as an annular gap or a longitudinal gap. 14. Shaft furnace according to claim 13, characterized in that the flow for the supply device is adjustable by means of a regulator (27) controlled depending on the temperature in the glow layer, and that the glow layer (18) is supported by a cone-shaped outlet device (17) which is arranged centrally in the shaft at the furnace's ash outlet and which is cooled and rotatably stored and at whose lower edge the passage is arranged. 15. Shaft furnace according to claim 12, 13 or 14, characterized in that the fuel gas line (11, 24) is connected to a recuperative heat exchanger (3, 16) for heating the loose material layer in the shaft. 16. Shaft furnace according to claim 14 or 15, characterized in that the supply device (21) is connected to cooling lines for the outlet device (17). 17. A shaft furnace according to claim 16, characterized in that the supply device (21) for gasification medium is led through the outlet device (17) and opens out centrally in the loose pulp layer (15) in the shaft furnace (4). 18. Shaft furnace according to one of claims 14 to 17, characterized in that an annular gap (19) is arranged between the edge of the cone at the lower edge of the cone-shaped outlet device (17). and the shaft furnace wall (20). 19. Shaft furnace according to one of claims 14 to 18, characterized in that the cone-shaped outlet device (17) has a cone surface (28) with a healing angle of 30 degrees, preferably a healing angle (29) of 20 degrees. 20. Shaft furnace according to one of claims 14 to 19, characterized in that guide ribs are placed on the rotatable outlet device (17) on the cone surface (28) facing the annealing layer (18). (30) for transporting material to be gasified in the glow layer to the outlet slot. 21. A shaft furnace according to one of claims 14 to 20, characterized in that on the rotatable outlet device (17) there are arranged vanes (33) which project down to the bottom of the shaft furnace (4) and serves to transport out the ash layer (32) which forms on the bottom of the shaft furnace (4). 22. Shaft furnace according to one of claims 14 to 21, characterized in that the loose mass layer (15) located in the shaft has such a height above the mouth of the supply device (21) for gasification medium that the flow resistance in the loose mass layer (15) above the mouth of the supply device (21) for the gasification medium is greater than the flow resistance into the supply device (21) for the gasification medium. 23. Shaft furnace according to one of claims 14 to 22, characterized in that a flow regulator (27) is inserted in the supply device (21) for the gasification medium which is controlled by the temperature in the glow layer. 24... Shaft furnace according to one of claims 14 to 23, characterized in that the outlet device (17) is arranged replaceable in the shaft furnace (4). 25. Device with a shaft furnace for carrying out the method according to claims 2 to 11 with a device for releasing heat for gasification of material located in the shaft, with an outlet device for the ash arranged at the bottom of the shaft furnace, characterized in that for the pretreatment of waste from organic materials by heat impact during air shut-off at temperatures up to approximately 550°C, a chamber (34) is arranged which is arranged in the shaft as a. another chamber (6) for heat action on the material at higher temperatures, where at the upper part of the shaft a supply device (5) opens into the gasification space (6) for adding gasification medium to the material to be gasified, and that the shaft is separated from the downstream room by a passage with a narrowing cross-section for the passage of the non-combustible residues remaining after the gasification, and that an exhaust (11) for the fuel gas is arranged immediately below the passage (7). 26. Device according to claim 25, characterized in that the passage is designed as an annular gap or a longitudinal gap. 27. Device according to one of claims 25 or 26, characterized by exhaust gas channels (3) connected to the shaft which in their course surround the outer wall of the first chamber. 28. Device according to one of the claims 25 to 27, characterized in that the first chamber intended for pre-treatment of the waste by drying and degassing is designed as a rotating drum (34) lying at an angle to the horizontal with a gas-tight sluice system (1) at the coating end, and whose other end opens into the upper part of the shaft which forms the gasification chamber (6), so that the material which is subjected to heat treatment after discharge from the rotary drum (34) enters the furnace shaft (4). 29. Device according to claim 28 for carrying out the method according to claim 11, characterized in that between the end of the rotary drum (34) and the shaft (6) there is arranged an externally shut-off intermediate chamber (35) which grips over the upper part of the shaft and which can be shut off by means of one or more gas-tight locks (36,37). 30., Device according to one of claims 28 and 29, characterized in that the upper part of the shaft (4) is completely or partially covered with a vibrating sieve (38) and that a shaft (39) for discharging non-combustible material and with a gas-tight sluice (37) is arranged in the upper part of the shaft (4) on the side facing the mouth of the rotary drum (34), with its lower shaft side level with the vibrating screen (38).