EP1338847A1 - Cocurrent Shaft Reactor - Google Patents

Abstract

A direct flow shaft reactor comprises a vertical shaft body (10) having a drying zone (14) for drying and heating the waste material, a degasifying zone (16) connected to the drying zone for degasifying the waste material, and a gasifying zone (18) for gasifying the waste material; a receiving body (20) connected to the shaft body for receiving molten waste material; and a gas removal unit (26) connected to the shaft body and/or the receiving body for removing the gases produced. Several gas feeding units (46) are provided in the transport direction of the waste material in the gasifying zone for feeding a gas into the degasifying zone. Preferred Features: The gas feeding units are uniformly distributed, preferably in a horizontal plane. Additional gas feeding units are provided in the drying zone and/or in the gasifying zone. The shaft body is cylindrical.

Description

The present invention relates to a DC shaft reactor for Melting and gasification of feedstocks of different kinds and Consistency, such as pollutant-free and / or polluted woods, Hausund Bulky waste, substitute fuels, pelleted dusts or animal meal, Plastics, industrial and commercial waste.

In shaft reactors, a synthesis gas which is used to produce electrical energy and heat is suitable and / or as the basis for Synthesis processes is used to be generated. As a solid product creates a non-leachable slag and a material weiterverarbeitbare Metal phase or a non-volatile liquid phase, which for a further processing is available.

DE 43 17 145 C1 describes a method and a device for degassing of waste materials based on a coke-heated countercurrent shaft furnace. Here, the resulting dust-containing gas is completely removed and in the underlying melting and overheating zone with oxygen burned high temperatures. The countercurrent flow of the gas through the down moving bed and the suction between the Kreislaufgasausaugung and the recirculation gas supply result in a variety of practical problems. The consequences are short-circuit currents in the shaft and insufficient heat transfer to the upper shaft area, creating a contaminated gas with tar and dust components arises. hereby a complex gas treatment and purification is necessary. Further there is a risk that tar and dust deposits the continuous operation is disturbed. Another permanent danger for one stable operation is the guidance of pyrolysis and degassing gas with tar Dust fractions in pipes. Partial or complete transfer of the Cables with tar dust deposits have an uneven Circulation gas guidance and thus uneven process control in the Shaft furnace result.

In DE 196 40 497 C2, a coke-heated Kreislaufgaskupolofen the material and / or energy recovery of waste materials described. It consists of a vertical furnace shaft with below the Settlement lying large-volume Kreislaufgasabsaugöffnungen through Channels and nozzles are connected to the melting and overheating zone, above which a large volume of excess gas is discharged resulting gas from the process leads. Here is the Ofenschachtteil between recycle gas and excess gas exhaust querschnittsverjüngt. The heat transfer takes place as in DE 43 17 145 C1 by rising countercurrent to the feedstock upwards Process gases. The multiple countercurrent flow of the gas through the down-moving bedding is possible despite some modifications by cross - sectional constriction in the shaft and cross - sectional widening in the shaft Gas outlet does not require the processing of a wide range of feedstock.

In addition, DE 198 16 864 A1 describes a cycle gas polyolefin, in which a surplus gas extraction below the melting and Overheating zone is arranged. This results in a Countercurrent gasification and heat transfer in the upper furnace shaft area, where the gas is sucked by means of large-volume openings and through Channels / nozzles is passed into the melting and overheating zone. In the subsequent DC gasification turns the gas at high temperatures reduced and split longer hydrocarbons. Through this Arrangement, the negative influence of short-circuit currents is reduced.

The spatial proximity of the endothermic processes to the hearth area and the large-volume excess gas extraction removes the melt necessary Heat to the necessary liquid under all operating conditions To ensure discharge of melt.

DE 100 07 115 A1 discloses a reactor for gasifying and / or melting Feedstocks with a feed zone, a degassing and gasification zone and a melting and overheating zone described. The dismantling and Gasification zone has a cross-sectional widening as Gaszuführraum, in the at least one combustion chamber opens with at least one burner, by which hot combustion gases a forming bulk cone be supplied. Furthermore, high-energy media by means of upper and lower injection agents in the area of the melting and overheating zone as well as above the melt by means of oxygen lances and / or nozzles brought in. The disadvantage of this device is the enlarged Reactor surface in the region of the cross-sectional expansion of the pyrolysis, since Heat losses occur. The entering in direct current in the bed hot gases also form preferred flow channels, which is a Inhomogeneous reaction over the reactor cross-section has the consequence.

Generally it can be assumed that with input materials with high Ignition points with poor heat conduction and with substances with high humidity the supplied heat in the degassing and gasification zone not to a sufficient heating and pyrolysis or degassing of the substances leads. The Processes of degassing and gasification shift into the area of Melting and overheating zone, thus reducing the reaction time Destruction of all forming tars and oils in the form of longer-chained Hydrocarbons. To avoid this would have supplied so much heat be that this results in sometimes so hot zones in the bulk material, which can damage the reactor wall and thus the operating time of a Significantly reduce shaft reactor.

All of the above described shaft reactors are only for one small range of starting materials used. Furthermore, for gasifying the Input materials are fed a significant amount of energy. this happens in particular over together with the bulk material or feed in the Shaft body introduced fuel, such as coke or the like. Furthermore, in known shaft reactors, regardless of whether they are in DC or countercurrent principle work, the problem that the taken gas is heavily loaded with particles and thus before a Further processing must be filtered, for example.

The object of the invention is a direct current reactor with which also when using different starting materials Nutzgase, in particular combustible Nutzgase with a low Particle load, can be generated in their generation the danger Damage to the DC-shaft reactor is reduced.

The object is achieved by the features of the invention Claim 1.

The inventive DC shaft reactor for melting and Gasification of feed has a vertical shaft body. Within the shaft body, the feedstock is dried, heated and gassed. The vertically arranged shaft body thus has in Transport direction successively a drying zone for drying and Heating the feedstock, a subsequent thereto Degassing zone for degassing the feed and a gasification zone for gasifying the feedstock. The shaft body is closed Receiving body, which is for receiving molten feedstock serves. Within this body, the melting zone of the reactor is formed. The shaft body and / or the receiving body are equipped with a gas discharge device for discharging the generated within the reactor Combined useful gases. In particular, the discharge device is in the range arranged between the shaft body and the receiving body and as Pipe formed. Furthermore, the vertically oriented shaft body has a Feeder on, through which the feed to the shaft reactor is supplied. In the degassing zone are in the transport direction of the Feedstock, i. in a vertical shaft body in vertical Direction one after the other in the degassing zone several gas supply units connected to the shaft body. By the Gas Zuführhreinhelten, where it is usually nozzles or the like., Is in the degassing zone Supplied gas, supported by the degassing of the feedstock or is accelerated.

The lower cylindrical or tapered area of the Gasification area protrudes into the melting zone if necessary. On this part lies the Schüttsäule located above at least partially, at the same time There are high temperatures there. For securing the mechanical Strength and protection from excessive temperatures According to the invention, a cooling by means of indirect water cooling in the Reactor shaft wall. Because at very high temperatures and the size of the too Cooling area a double-walled design of the reactor shaft wall due to overheating and thereby caused destruction is disadvantageous, this is cylindrical or itself tapered region formed according to the invention as a pipe coil. A spiral pipe coil, which is traversed by a cooling medium is particularly suitable for the realization of cooling in this area. In particular, a targeted cooling is possible. The danger of steam formation inside the coil is very due to the circulation of the liquid low. The coil is preferably in several areas with separate inflows and outflows, so that too much warming Coolant can be discharged directly from the coil.

As a result, an evaporation of the cooling liquid with vapor formation and thus associated reduction in the cooling effect avoided. Between individual rings or spiral parts of the coil can additionally nozzles or burner may be provided, so that the process control in this Area can be controlled very precisely. Thus, in particular the Temperature can be controlled precisely in this area, the Control preferably separately and thus independent of the regulation of remaining nozzles and burner.

Due to the arrangement of several gas supply units in the transport direction one after the other, the degassing zone can be better utilized, so that too With different starting materials degassing of these substances is possible. As by feeding the gases in the degassing zone in particular energy and that heat is introduced into the degassing zone, in the Entgasungszone over the cross section a more uniform heating of the Feedstock be ensured. As in the invention several gas supply units In the transport direction are arranged one behind the other, can a preferably continuous heating of the feedstock in Transport direction can be ensured. This makes it possible that too be degassed difficult to degasified feedstocks in the degassing. Since the degassing thus predominantly in the degassing of the Duct reactor according to the invention is a degassing reduced by feedstock in the gasification or the melting zone or avoided. As a result, the efficiency of the shaft reactor considerably increase. Through the shaft reactor according to the invention can in the Degassing a high degree of degassing be realized, so that Flammable Nutzgase can be generated, which is only a very small Have particle load.

To a uniform as possible heating of the feed in the To enable degasification zone, the gas supply units are preferably arranged substantially uniformly distributed. The gas feed units thus have a substantially equal distance to each other. Preferably, in this case, the individual gas supply units or more each combined into a group or feed unit Feeding devices connected to a control device. With the help of Control device, it is possible, the individual gas supply units and / or to control or regulate the feed units separately. This can for example, by a regulation of the individual gas supply units discharged gas quantity, the oxygen content of the supplied gas and / or the temperature of the supplied gas. Further, too the gas mixture can be changed.

The invention will be described below with reference to a preferred embodiment explained with reference to the accompanying drawings.

The figure shows a schematic side view of a DC-shaft reactor.

The DC shaft reactor has a shaft body 10. Of the Shaft body 10 may in the illustrated embodiment in a Lock assembly 12, one to the lock assembly 12th subsequent drying zone 14, one to the drying zone 14th subsequent degassing zone 16 and a subsequent thereto Gasification zone 18 are divided. To the gasification zone 18 of the Shaft body 10 is followed by a receiving body 20, which is for receiving of molten feedstock 22 is used. In the upper area of the Receiving body 20, the melting zone 23 is formed. In the border area between the gasification zone 18 and the receiving body 20 is the Extended cross-section of the receiving body, leaving a ring-shaped trained gas collection chamber 24 is formed, which is the lower part of Gasification zone 18 surrounds. The gas collection chamber 24 is provided with an im illustrated embodiment designed as a pipe gas discharge device 26 connected.

The feedstock is fed into the well body 10 through a feed opening 28 introduced via the lock assembly 12. Feeding the Feedstock via the lock assembly to the introduction large amounts of ambient air through which the melting and Gasification process can be influenced uncontrollably, to prevent. For this purpose, the lock arrangement has two lock devices or Sluice gates 30,32 on, between which the lock chamber 34 is formed, the lock chamber 34 is already part of the Shaft body 10 is.

The feed then passes through the lock assembly 12 in the Drying zone 14. In the drying zone 14 and the subsequent zones 16, 18 the shaft body 10 is almost complete with during operation Feedstock filled. Also in the drying zone 14 no or forms if necessary, a small pour cone near the lock gate 32. Of the Well body 10 is thus at least in the region of the degassing 16 cylindrical or widening in the transport direction without jerking. The shaft inner wall of the shaft body 10 is thus at least in the Degassing zone 16 smooth and has no steps or the like. On.

In the illustrated embodiment is in the dry zone of the Shaft body 10, a gas supply unit 36 is provided. The gas supply unit 36 has a ring conduit 38 surrounding the shaft body 10 connected to a plurality of evenly circumferentially distributed nozzles 40 is. About the gas supply unit 36 is the feedstock in the field of Drying zone 14 preferably hot air, which optionally enriched with oxygen may be fed to dry the feedstock.

In which subsequent to the drying zone 14 degassing zone 16 are a plurality of gas feeders 46, which are in particular to Nozzles act, provided. In the degassing zone 16 are the gas feeders 46 evenly distributed. In particular, in Transport direction of the feedstock, i. in the figure from top to bottom, a plurality of gas supply means or nozzles 46 arranged one after the other. Preferably, it is at least three successively arranged Nozzles 46. In the illustrated embodiment, a plurality of nozzles 46 to a feed unit 42 connected. For this purpose, a ring line 44 is provided, for which the nozzles 46 can be supplied together with gas. The Ring line 44 is therefore preferably uniform with several on the circumference distributed nozzles 46 connected. In particular, each ring line 44 at least three nozzles on. The ring lines 44, each in a horizontal plane are arranged, together with the nozzles or Gas feeders 46 individual feed units 42. Within the Degassing zone 16 are several in the illustrated embodiment four Feeding units 42 arranged. It is particularly preferred according to the invention provide at least two feed units. The individual feeding units 42 are offset from each other or arranged rotated, so that in Transport direction of the feed material successively arranged nozzles 46th not over, or behind each other, but offset, or next to each other are arranged. Preferably, the individual delivery units face each other the above arranged feed unit by the same angle arranged twisted. The size of the angle of rotation is preferably from the number of each supply unit 42 provided nozzles 46 depending, so that a substantially uniform distribution of the nozzles 46 in the Degassing zone 16 takes place. About the gas supply means 46 can high-energy gases, oxygen, air or others to control the Schmelzund Gasification process suitable gases fed to the feedstock become.

Further nozzles 48 are provided in the gasification zone 18. About the nozzles 48 can in turn high-energy gas or other the melting and Gasification process controlling gases or substances are supplied. As well may be provided instead of the nozzle 48 and burner, which in the Gasification zone 18 immediately supply heat to the feedstock. Of the End region of the longitudinal axis 50 rotationally symmetrical shaft body 10th is tapered slightly tapered so that the feed material in the Part of the gasification zone 18 is retained somewhat.

In a side wall 52 of the receiving body 20 are also several on Circumferentially distributed nozzles 54 arranged. The nozzles 54 serve for introduction high-energy gases or corresponding substances. Through the nozzles 54 is ensures that the melt 22 remains liquid. Likewise, instead of the Nozzles 54 may also be provided burners.

Preferably, a side wall 56 of the lock assembly 12 double-walled design. This can cause a warming and thus a Drying of the feed in the lock chamber 34 can be achieved by passing a hot medium through the double-walled side wall 68 becomes. This is preferably air or another gas. In particular, it is also possible for the gas supply unit 36 instead of in the area the drying zone 14 in the area of the lock assembly 12 provide.

The lock assembly 12 has the task of continuous and homogeneous supply of material and the gas-tight seal against the Surroundings.

The ideal material input preferably sets a homogeneous mixture especially when adding additives such as coke and lime. Of the Entry takes place according to the invention centrally on the axis of the reactor. The Volume of the lock chamber 34 is fully utilized as possible and falls into the reactor shaft of the same diameter as possible. The reactor is keep as full as possible during operation. A level monitoring is Accordingly, preferably mounted directly below the lock gate 32. The Filling takes place in a high clock rate. These measures will at the same time reduces the false air intake and the pressure in the Overall system improved.

According to the invention, the areas are lock arrangement 12, drying zone 14 and degassing zone 16 into the gasification zone 18 preferably cylindrical or slightly conical widening downwards. Of the Transition between the zones takes place without step-shaped or erratic Cross-sectional enlargement, i. the transition is the same cross section and without formation of shake-free cavities, steps or edges.

The drying zone 14 can also, in particular for larger types be executed double-walled. This allows the indirect heating of the Gutsäule inside or to ensure a uniform temperature the wall and a reduction of condensation phenomena at the Inside. The heat transfer medium is preferably also hot air used.

When heating the starting material takes place in the drying zone 14 the Evaporation of the water instead. The temperature in the estate rises only slightly above 100 ° C. As the temperature increases, as the process progresses adsorbed gases such as nitrogen and carbon dioxide released, which are not caused by fission reactions. At the latest here can from the Degassing be spoken. Above 250 to 300 ° C then sets the Development of gases and vapors, which distilled off low molecular weight compounds and first cleavage products. Another one Increasing the temperature causes the flow of reactions leading to the formation of methane and hydrogen.

The degassing zone 16 can also continue in the drying zone 14 be designed double-walled.

In the lower third of the drying and degassing 14,16 results in a Range in which the internal reactor temperature is greater than the Hot air temperature is. Here, the double-walled version by a siliceous lining to be replaced. An execution of the whole Drying and degassing 14,16 with a ramming mass, even at a double-walled design, is advantageous. Less wear of the Steel construction shell are less heat transfer and lower Thermal shock resistance.

In the further warming of the pouring column from about 700 ° C takes place in addition to the Implementation of the fuel under the influence of heat the heterogeneous Reaction between the fuel and the unreacted oxygen the air.

The gasification zone 18 is the main reaction zone within the well reactor. Here, the material takes place at temperatures of 1,200 to 1,400 ° C. and energetic conversion of the solids. From the solid fuel Gases and solid products form from coke to ash. For the full and uniform reaction is crucial to having a homogeneous bed by the already formed degassing gas and the here to be introduced Gasification agent is flowed through evenly. The gasification zone 18 must for these reasons have a sufficient height. This will be so far achieved in that the gasification zone 18 as a straight cylindrical Area with transition into a conical reduction of the cross section or is immediately formed as an increasing rejuvenation. As by the material transformations and related destructive forces the material grain is reduced, the cavities increase within the Bulk column. By the reduction of the shaft cross-section in this Range can even out the rate of descent of the column of material flow channels are destroyed and the formation of larger ones Cavities in the bed is avoided.

In continuation of the overlying degassing zone 16 is the range of Gasification also lined with a silicate mass.

The gas flows in co-current with the feedstock the zone of High-temperature gasification 18. The from the expired degassing and Thermolysis reactions resulting longer-chain hydrocarbons are here thermally split and were at the same time at the expiring Gasification processes involved. The result is a flammable gas medium Calorific value with the main components carbon monoxide, carbon dioxide, Hydrogen and water vapor without constituents of condensable Hydrocarbons. Many of the chemical reactions that have taken place are endothermic. The temperature of the gas as well as the bed decreases thus.

In the lower cylindrical or tapered area of the Gasification region 18, which optionally projects into the melting zone 23, is the Pipe coil 60 according to the invention arranged. It is preferably with in the figure not shown separate feeds and drains provided. Further can between the individual rings or spiral parts of the coil 60th additional nozzles 48 or burners 54 are provided. Below the water-cooled region of the gasification region 18, the gas undergoes a Deflection by about 180 ° and enters the shake-free space 24th By endothermic processes described above, the gas has a Temperature of about 1,000 ° C. After a certain gas calming and - Evenly, the gas is sucked out of the reactor above.

The gas collection chamber 24 is already part of the melting zone 23, which above substantially further than the projecting gasification zone 18, and surrounds the gasification zone 18 at least partially. The cylindrical Melting zone 23 reduces conically downwards and closes with the Base plate above which collects the molten phase.

The melting zone 23 is in its entirety with a multi-layered Provided rammed or equipped with a lining. reason this is the necessary high temperatures. Only in the area of Gassammelraumes is under certain circumstances a lining not necessary.

The completely degassed and coked solid, is already in places sintered or melted and sinks from the gasification zone 18 further into the Melting zone 23.

Integrated into the melting zone 23 is a plane with a plurality of oxygen nozzles or injectors and / or oxidizing burners 54, which also are distributed symmetrically on the axis.

The supply of gas with a high oxygen content occurs strong exothermic reactions with the gas and the solid from the Gasification zone 18. There are temperatures which are well above the Melting point of the material, usually about 1400 ° C to 1600 ° C. in the Area of the oxygen nozzles even result in hot temperature zones of 1800 to 2000 ° C. Under these conditions and by the addition of Slag formers and / or materials which lower the melting point, All inorganic pollutants are safely melted.

The molten material collects as a melt at the bottom of the Reactor. The emptying of this liquid melt takes place as in the foundry usual about a tap hole and a gutter 72. A design with forehearth or Siphon is possible.

With sufficiently large design and appropriate residence time of the melt the melt will turn into a heavy metal-containing phase and one on top Separate floating slag. Here is the possibility over different high discharges a usable metallic phase and a To be able to win cinder In the product slag are not organic Contain substances and the inorganic constituents are in a silicate Matrix stably installed. The use as material for the port, landfill and Road construction are known, as is possible the production of special Molds and products as they are common in the glass industry.

Claims (13)

DC shaft reactor for melting and gasifying feedstock, with
a vertical shaft body (10) having a drying zone (14) for drying and heating the feedstock, a degassing zone (16) following the drying zone (14) for degassing the feedstock and a gasification zone (18) for gasifying the feedstock, the feedstock is transported from the drying zone (14) through the degassing zone (16) into the gasification zone (18),
a receiving body (20) adjoining the shaft body (10) for receiving molten feedstock (22), and
a gas discharge device (26) connected to the shaft body (10) and / or the receiving body (20) for discharging resulting gases,
wherein in the transport direction of the feedstock in the degassing zone (16) a plurality of gas feed units (42) connected to the shaft body (10) are successively provided for feeding gas into the degassing zone (16),
characterized in that in the region of the transition between the gasification zone (18) and the melting zone (23) for temperature control, a coil (60) is provided. A DC reactor according to claim 1, characterized in that the coil (60) is spiral. Direct-shaft reactor according to claim 1 or 2, characterized in that by the tube coil (60) is formed in the transport direction of the feed material tapering region, in particular conically tapered region. Direct-shaft reactor according to one of claims 1 - 3, characterized in that the coil (60) is connected in several areas with separate inflows and outflows. Direct-shaft reactor according to one of claims 1 - 4, characterized in that the gas supply means (46) are arranged distributed substantially uniformly. Direct-shaft reactor according to one of claims 1 - 5, characterized in that in the transport direction at least three gas supply means (46) are provided successively. A DC-shaft reactor according to any one of claims 1-6, characterized in that a plurality of gas supply means (46) are arranged in a horizontal plane. Direct-shaft reactor according to one of claims 1 - 7, characterized in that arranged in a plane gas supply means (46) are connected to a ring line (44) to a feed unit (42). Direct-shaft reactor according to claim 8, characterized in that the gas supply means (46) are arranged offset from one another in the transport direction successively arranged feed units (42). Direct-shaft reactor according to one of claims 1 - 4, characterized in that between the individual rings or spiral parts of the coil (60) additionally nozzles (48) or burners (54) are provided, which are in particular separately controllable. Direct-shaft reactor according to one of claims 1 - 10, characterized in that the gas supply means (46) and / or the feed units (42) are connected to a control device. Direct-shaft reactor according to one of claims 1 - 11, characterized in that in the drying zone (14) and / or gasification zone (18) additional gas supply means (46,48) are provided. Direct-shaft reactor according to one of claims 1 - 12, characterized in that the shaft body (10) is cylindrical at least in the region of the degassing zone (16) or widening without jerking in the transport direction.

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