CN106701201B

CN106701201B - Gas-bed reactor for producing synthesis gas

Info

Publication number: CN106701201B
Application number: CN201610076176.4A
Authority: CN
Inventors: 法比安·艾佐尔德
Original assignee: Choren Industrietechnik GmbH
Current assignee: Choren Industrietechnik GmbH
Priority date: 2015-11-13
Filing date: 2016-02-03
Publication date: 2021-01-08
Anticipated expiration: 2036-02-03
Also published as: DE102015119696B4; CN205740914U; DE102015119696A1; CN106701201A

Abstract

The present invention relates to a entrained flow reactor for the production of synthesis gas. The object on which the invention is based is to provide a structural improvement in the slag tapping region which overcomes the mentioned disadvantages in the prior art and ensures an effective, permanent protection of all reactor components in the slag tapping region. This object is achieved by a horizontal intermediate floor which closes the quenching space upwards, wherein the intermediate floor extends at the level of the slag discharge from the reactor wall to the slag discharge and is connected in a gas-tight manner to the reactor wall and to the slag discharge; this is achieved by gas-tight connections between the cooling screen and the slag discharger and by cooling water supply and discharge channels in the reactor, which are assigned to the cooling screen and the slag discharger and are introduced into the reactor above the intermediate floor and are connected to the coils of the cooling screen and the slag discharger above the intermediate floor.

Description

Gas-bed reactor for producing synthesis gas

Technical Field

The invention relates to a entrained-flow reactor for producing synthesis gas from carbonaceous fuels.

Background

A fluidized bed reactor of this type generally comprises an outer, pressure-bearing reactor wall which encloses a reaction chamber for the formation of crude gas and residues and a cylindrical cooling screen which delimits the reaction chamber from the reactor wall. The cooling screen is formed by a coil through which cooling water can flow and has a conical lower section. An annular space is present between the cooling screen and the reactor wall, which annular space can be purged with an inert gas. The entrained-flow reactor also has a quenching space which is connected to the reaction chamber and is used for cooling the raw gas in such a way that the raw gas is brought into contact with water. The conical lower section of the cooling screen is continued by a funnel-shaped body which surrounds a concentric opening between the reactor wall and the quenching space. The funnel-shaped body serves to overflow crude gas and residues from the reaction chamber into the quenching space and is referred to as slag discharge. The slag tap body has a funnel-shaped coil through which cooling water flows and which has a protective coating.

The entrained-flow reactor is a reactor which essentially consists of a reaction chamber in which reaction partners (reactionpartner) in the flue gas (Flugwolke) or in the gas stream react with one another and a cooling space (quench) connected to the reaction chamber. The entrained-flow reactor can be used, for example, for producing hydrogen-rich and carbon monoxide-rich gases which are used for energy purposes as synthesis gas, reducing gas, town gas or coal gas. In a process known as "gasification", an organic fuel is reacted with a gasifying agent containing oxygen at elevated pressure and temperature. In this case, the carbon reacts in the exothermic partial oxidation to carbon monoxide, wherein, in addition to the desired raw gases, a mineral residue in the form of a residue in the molten liquid state is also produced.

In the production of synthesis gas, ash-like coal is gasified in a flame reaction in the presence of oxygen and steam or carbon dioxide in a flue gas at temperatures of 1200 ℃ to 1800 ℃ and pressures of up to 80 bar, in principle in a similar manner for the gasification of liquid fuels (tar, residual oil), suspensions from liquid or solid fuels or for torrefied biomass.

The location of the one or more gasification burners is located in the upper part of the reaction chambers of the entrained-flow reactor, through which the reaction medium is supplied to the fuel or oxygen. Synthesis gas and liquid residues are discharged into the quench space through a slag discharge opening below the intermediate floor.

In entrained-flow gasifiers, it is known to confine the reaction chamber by means of a multi-wire cylindrical heat exchanger (also referred to as a cooling screen) which is wound in a spiral from a tube and thus to protect the pressure-bearing reactor walls from the exothermic, partially oxidized, hot reaction products. The cooling screen narrows generally conically at the upper portion in the direction towards the burner/burners and conically at the lower portion in the direction towards the gas discharge opening and the slag discharge opening. An annular space capable of being purged with an inert gas is located between the pressure shield and the cooling shield. The cooling water flowing through the cooling screen is fed or discharged through the reactor wall by means of connecting branches.

In order to avoid local overheating of the cooling screen, the number of lines connected in parallel is increased in the case of increasing gasifier capacity. The number of connecting branches and branch penetrations per positive and return flow may be reduced due to the greater number of lines that may result in more branches passing through the pressure vessel, for example by the arrangement of internal annular distributor and collector lines in the lower region.

The gasification reactor is configured in such a way that slag particles in the molten liquid state, which are produced during the oxidation of the coal particles in the flame region of the gasification burner and precipitate at the reaction chamber wall, can be discharged from the reaction chamber without interference into a cooling space or quenching space arranged below the reaction chamber. For this purpose, the floor of the reaction chamber, which is surrounded by the cooling screen, is formed in a funnel-like manner in the direction of the central slag discharge opening.

The slag particles in the molten liquid state which are also retained in the gas stream are usually cooled to below the melting point in the quenching space of the entrained-flow reactor by means of water injection or by conducting the crude gas charged with slag through a water bath and are discharged from the reactor as particles suspended in water.

The reactor elements (e.g. quench nozzles, gas guide elements or pipelines) in the intermediate bottom region surrounding the slag tap body are subject to severe wear and essentially jointly determine the service life of the gasification reactor. The reactor elements are corroded by the molten liquid slag flow, while hot, corrosive raw gases are conducted out of the reaction chamber through slag discharge openings into the connected quenching spaces, and additionally the intermediate floor region between the reaction chamber and the quenching spaces is subjected to the action of heat and the action of an atmosphere from the moisture-laden quenching spaces. The intermediate floor region around the slag discharge opening with the cooling water lines arranged in this region is therefore one of the most corrosion-demanding reactor regions.

The operational lifetime that can be used for gasification has a significant impact on the economics of the coal gasification reactor. Each process interruption (due to unstable gasification parameters or due to maintenance of worn-out plant components) leads to high costs and downtime due to the associated high-cost start-up and shut-down processes and installation and removal work at the pressure-resistant gasification reactor. The corrosion resistance of the intermediate floor region between the reaction chamber and the quench space and the configuration which at the same time facilitates maintenance make a very important contribution to reducing maintenance costs.

DE 4025916 a1 discloses a fluidized-bed reactor whose funnel-shaped slag discharge body consists of a cooling coil with a slag protective coating and is inserted into a conical section of a cooling screen. The slag discharge body is supported together with the cooling screen on a support ring at the reactor wall. The gap between the slag tap and the cooling screen is filled with a refractory material. A disadvantage of this arrangement is that the cooling water feed channel and the cooling water discharge channel are open-circuited through the upper region of the quench space and thus corrosive gases can enter unimpeded.

DE 4025955 a1 or EP 0459023 a1 are further examples of unprotected cooling water conduit arrangements which are located in the upper region of the quench space between the slag tapping body and the reactor wall.

A measure for protecting the cooling water connections of cooling screens is already known from DE 202013105709U. The cooling water connection for the cooling screen is arranged in an inerted region in the lower conical section of the annular space outside the cooling screen, wherein, to obtain construction space, the cooling water feed channel and the cooling water discharge channel in series are led to upright collecting vessels or distributors which are connected by means of only one further line to a cooling system outside the reactor. No measures for protecting the cooling water lines of the slag discharger are known from this document.

It is also known that: corrosion-resistant tube materials are used to protect the lines in the quenching space, or the dead space around the slag tap-off body, which is caused by the structure, is purged with inert gas with high effort to avoid hidden corrosion at the supporting elements of the intermediate floor, or to provide ventilation out of the annular space.

The disadvantage of these solutions is that they are costly and only form individual measures for suppressing corrosion damage, which do not achieve complete protection.

Disclosure of Invention

The invention is therefore based on the object of providing a structural improvement in the slag tapping region which overcomes the disadvantages mentioned in the prior art and ensures an effective, permanent protection of all reactor components in the region of the slag tapping body and in the region of the intermediate floor.

The solution proposed for this purpose provides that the annular space is separated from the quenching space in a gas-tight manner by means of an intermediate floor. For this purpose, the intermediate floor extends at the level of the slag discharge body from the reactor wall to the slag discharge body and is connected in a gas-tight manner to the reactor wall and to the slag discharge body. There is a further gas-tight connection between the cooling screen and the slag tap body. Furthermore, in the reactor, all cooling water feed channels and cooling water discharge channels assigned to the cooling screen and the slag discharger are introduced above the intermediate floor (which closes the quench space horizontally upwards) into the inert gas-purged annular space (also referred to as inerted region) of the reactor and there are connected to the coils of the cooling screen and the slag discharger. Advantageous embodiments are the subject of the dependent claims. In the case of known configurations in which the reaction chamber is also separated from the annular space in a gas-tight manner, the ingress of corrosive gases from the reaction chamber into the annular space can also be reliably avoided.

The penetration of corrosive gases from the quench space and from the reaction chamber into the annular space region is reliably prevented by the open construction of the slag discharger relative to the inert gas-purged annular space (in order to likewise purge the outside of the slag discharger with inert gas) and the closing of the gas seal of the quench space upwards at the level of the slag discharger and the gas-tight connection between the cooling screen and the slag discharger. This eliminates the need to purge the dead space in the slag tap body.

All feed channels out of and towards the cooling water lines and the cooling water lines themselves can be manufactured cost-effectively in C-steel.

The number of construction spaces in the annular space and branch lines for the reactor wall through-openings can be reduced by using collectors for the cooling screens and for the cooling elements of the slag tapping body.

The contact surfaces of the cooling tube and the support and sealing means, which are inevitably exposed to the quenching space atmosphere, are reduced and configured to have a fully protective corrosion-resistant surface.

The proposed solution also advantageously simplifies the structural design in the intermediate floor region to such an extent that only small amounts of residual dirt and adhering erosion points remain. The portion of the slag tap body protruding into the quenching space is shorter than in the known embodiments, whereby the risk of sticking and clogging in the slag tap body is reduced.

Due to the improved accessibility of the support elements for the cooling screens, it can be proposed to advantageously use height adjustment devices which, in addition to adjusting the cooling screens during installation, also enable a temporary lowering of the cooling screens in the reactor, so that the installation joints in the upper reactor region can be accessed, implemented and checked more easily.

Since no connecting lines for the slag tapping body are present below the intermediate floor, simple connection of further components can also be achieved in the upper quenching region. Furthermore, there are also less risky surfaces that may cause adhesion.

The features of the invention described above and in the appended claims can be combined with one another without difficulty by the person skilled in the art in other embodiments than those described, if this is considered obvious and meaningful.

Drawings

The present invention should be exemplarily explained as follows. The attached drawings show here:

FIG. 1: a schematic cross-sectional illustration of an annular space surrounding the slag tap body

Detailed Description

The entrained-flow reactor for producing synthesis gas from carbon-containing fuels according to the Downstream principle (Downstream-Prinzip) is composed firstly of an outer, pressure-bearing jacket (reactor wall 1). In the upper part of the reactor a reaction chamber is arranged, in which crude gas and residues are formed at high temperature and at high pressure. In order to protect the pressurized reactor wall 1, the reaction chamber is bounded by a cylindrical cooling screen 2 which has a conical lower section and consists of coils through which cooling water flows, which coils are connected to one another in a gas-tight manner.

Between the reactor wall 1 and the cooling screen 2 there is an annular space 16 which can be purged with an externally feedable inert gas in order to protect the reactor wall 1 and the cooling screen 2 from corrosion caused by stray reaction gases.

A quenching space 17 connects the reaction chamber in the flow direction of the raw gas, in which the raw gas is cooled by direct or indirect contact with water.

A horizontal intermediate floor closes the quenching space 17 upwards and contains a central opening in which a funnel-shaped body, called slag discharge body 6, is supported. The funnel-shaped body continues a conical lower section of the cooling screen 2 and encloses a concentric opening between the reaction chamber and the quenching space 17, through which the coarse gases and residues overflow from the reaction chamber into the quenching space 17. The slag tap body 6 has on the inner side facing the opening at least one coil through which cooling water flows, having a protective coating which is resistant to fire and to residues.

The slag tap body 6 is distinguished in that it consists of two mutually internal, cylindrical layers of coils (which are hydraulically connected to one another) in the lower section which projects into the quenching chamber, i.e. consists of a continuous cooling line. The outer layer 13 of the coil consists of a corrosion resistant steel and the inner layer 14 of the coil of the slag discharging body 6 consists of C steel.

The C steel and the corrosion-resistant material are separated at a limiting plate 15, which consists of a heat-resistant material. The delimiting plate 15 is formed in an annular shape and is welded to the slag tap body 6 at the lower end of the slag tap body 6 between the inner and

outer layers

13, 14 of the coil. The limiting plate simultaneously serves as a stop for a refractory lining.

The slag tap body 6 likewise has an outer coil at the upper end, which surrounds the funnel-shaped part of the inner coil 14 from the outside in the manner of a collar and at the same time extends its coil system. The coiled collar 19 is located at the level of the conically narrowing lower section of the cooling screen 2, wherein an elongated gap remains between the coiled collar 19 of the slag discharge body 6 and the cooling screen 2. The annular gap is closed in a gas-tight manner downwards by means of a vertically flexibly formed, trough-like or U-shaped annular plate 8.

For this purpose, the annular plate 8 is welded along the respective lower coil to the coil collar 19 of the slag discharge body 6 and to the cooling screen 2. The flexibility of the annular plate 8 serves to compensate for the different thermal expansions of the cooling screen and of the cooling water coil of the slag tapping body and can be achieved, for example, by a semicircular, elastic bending piece in the vertical direction (as shown in fig. 1).

The embodiment of the annular plate 8 shown in the figures is only an example and other configurations do not depart from the scope of protection.

For inspection purposes, the annular plate 8 is sufficiently accessible to enable it to be separated and welded again when required.

The intermediate floor extends from the reactor wall 1 to the slag tap body 6 at the level of the slag tap body 6, preferably at the level of the cylindrical lower section of the slag tap body 6. The intermediate floor is connected in a gas-tight manner to the reactor wall 1 and the slag tapping body 6, wherein the intermediate floor is preferably welded to the reactor wall 1.

All cooling water feed channels and cooling water discharge channels in the reactor, which are assigned to the cooling screen 2 and the slag discharging body 6, are introduced into the reactor above the intermediate floor and are connected with the coils of the cooling screen 2 and the slag discharging body 6 above the intermediate floor in the annular space 16.

A disk-shaped or arched support plate 12, which is welded horizontally in a gas-tight manner into the reactor wall 1 at the level of the slag discharge body 6, serves as an intermediate floor. The support plate 12 can have a corrosion-resistant coating on its underside facing the quenching space, which can be embodied, for example, as a corrosion-resistant weld deposit.

The support plate 12 has a central opening which is larger than the outer diameter of the slag tap body 6, wherein the central opening is limited by an annular reinforcement. In this exemplary embodiment, the annular reinforcement is formed as a support ring, which is connected to the support plate 12. Alternatively, the annular stiffener may be formed in one piece in the support plate 12 itself or in another suitable manner.

A vertical ring 11, which is in the form of a cylindrical outer support ring, is welded gas-tightly to the outer circumference of the slag discharge body 6, a horizontal annular plate 18 is in turn welded gas-tightly to the ring, the outer diameter of the annular plate 18 being greater than the inner diameter of the support ring.

The annular plate 18 is releasably connected, preferably screwed, to the bearing ring via a seal 10, in particular a soft seal being used here. The annular plate 18 is corrosion-resistant coated or consists of a corrosion-resistant stainless steel at least at the underside, the ring 11 preferably being made of a corrosion-resistant alloy. Alternative embodiments are also possible for the gas-tight connection and configuration of the corrosion-resistant annular plate 18 at least with respect to the quenching space 17.

Four vertically arranged collectors 7 are arranged above the support plate 12 in the annular space 16 for the cooling water feed and cooling water discharge channels of the cooling screen 2 and the slag tap body 6 and are connected to the coils of the cooling screen 2 and the slag tap body 6 by connecting pipes in the annular space 16, wherein the collectors 7 themselves are each connected to a cooling system outside the reactor by a pipe feedthrough in the reactor wall 1. "accumulator" (Sammler) is understood to mean an extended pipe into which all feed and discharge channels from the cooling line of the cooling screen 2 or the slag tap 6 open. The connecting lines 9 leading radially between the coil and the collector 7 are accessible, simply connectable and have a detectable tightness by means of a manhole (not shown) arranged at the height of the slag discharge body 6 in the reactor wall 1.

The cooling screen 2 is supported on at least three supports at the inner wall of the reactor above the support plate 12, wherein the supports are dimensioned in such a way that they can jointly receive the total load and the additional load of the cooling screen 2.

Each of the supports consists of a first fastening plate 3 below the conical coiled section of the cooling screen 2, a second fastening plate 5 welded at the reactor wall 1 and a height adjustment device 4 between the first and

second fastening plates

3, 5. The supports are arranged at regular intervals along the circumference of the cooling screen and are dimensioned in such a way that manufacturing tolerances, in particular length and position deviations of the cooling screen 2, can be compensated for by means of the height adjustment devices 4.

For installation purposes, for example for the production of installation joints at the reactor wall 1, the cooling screen 2 can also be lowered deeper than the actual end position by means of the height adjustment device 4, in order to create an additional installation free space above the cooling screen 2.

The height adjustment means 4 are accessible through a manhole, since the proposed construction provides a larger free space in the annular space 16 behind the conical section of the cooling screen 2. These height adjusting means 4 can be formed, for example, as a length-adjustable threaded rod, an adjustable wedge, a scissor drive or an eccentric drive.

The proposed solution also offers the possibility that all other feed channels or connections, for example signal lines or media lines, for the cooling screen 2 and for the slag tapping body 6 are likewise arranged in the inerted region above the support plate 12.

In one embodiment, the cooling water for the slag tap body 6 is fed from an external cooling system via the collector 7 and the radial connecting line 9 into the lower outer layer 13 of the coil of the slag tap body 6, flows downwards through the outer layer 13 of the coil in the direction of the delimiting plate 15, then flows upwards through the entire inner layer 14 of the coil of the slag tap body 6 and then flows downwards through the upper, coiled collar 19 up to the annular plate 8. The cooling water is discharged in the last coil on the annular plate 8 outwards into a further (not shown) collector in the annular space and from there outwards through the reactor wall 1 to an external cooling system.

By means of the special arrangement of the coils in the slag tapping body and the gas-tight separation of the quenching space 17, it is possible to feed cooling water into and discharge cooling water from the inerted construction space above the support plate 12. In connection with the corrosion-protecting surfaces of the outer layer 13 of the coil, the ring 11 and the annular plate 18, corrosion attack on the cooling water system of the entrained flow reactor is effectively avoided.

The person skilled in the art can combine the features previously achieved in different configurations of the invention in other embodiments conveniently.

List of reference numerals

1 reactor wall

2 Cooling Screen

3 first fastening plate

4 height adjusting device

5 second fastening plate

6 slag discharger

7 collector

8 annular plate

9 connecting conduit of collector

10 seal

11 Ring

12 bearing plate with bearing ring

Outer layer of 13 coil

Inner layer of 14 coil pipe

15 limiting plate

16 annular space

17 quenching space

18 annular plate

19 coiled lantern ring

Claims

1. Fluidized bed reactor for producing synthesis gas from a carbonaceous fuel, having an outer, pressure-bearing reactor wall (1) which surrounds the reactor wall

-a reaction chamber for forming a crude gas and a residue,

-a cylindrical cooling screen (2) which delimits the reaction chamber from the reactor wall (1), which cooling screen is formed by a coil through which cooling water can flow and has a conical lower section,

-an annular space (16) between the cooling screen (2) and the reactor wall (1), which annular space can be purged with an inert gas,

-a quenching space (17) connecting the reaction chamber, in which quenching space the raw gas is cooled in contact with water, and

-a funnel-shaped body, called slag tap (6), for overflowing coarse gases and residues from the reaction chamber into the quenching space (17), which continues the conical lower section of the cooling screen (2) and surrounds a concentric opening between reaction chamber and quenching space (17), wherein the slag tap (6) has a coil with protective coating through which funnel-shaped and cooling water flows,

it is characterized in that the preparation method is characterized in that,

-a horizontal intermediate floor closes the quenching space (17) upwards, wherein the intermediate floor extends from the reactor wall (1) to the slag tap body (6) at the level of the slag tap body (6) and is connected gas-tightly with the reactor wall (1) and the slag tap body (6),

-the slag tap body (6) has a coiled collar (19), which coiled collar (19) surrounds the funnel-shaped part of the coil (14) of the slag tap body (6) from the outside in the form of a collar, wherein a gas-tight annular plate is present between the cooling screen (2) and the slag tap body (6), wherein the annular plate (8) is connected gas-tightly to the cooling screen (2) and to the coiled collar (19) of the slag tap body (6), and

-all cooling water feed channels and cooling water discharge channels in the reactor, which are assigned to the cooling screen (2) and the slag discharging body (6), are introduced into the reactor above the intermediate floor and are connected with the coils of the cooling screen (2) and the slag discharging body (6) above the intermediate floor.

2. The entrained flow reactor of claim 1,

the intermediate floor is formed by a plate-like or an arched support plate (12),

the support plate is welded to the reactor wall (1) in a gas-tight manner horizontally at the level of the slag tap body (6) and has a central opening which is larger than the outer diameter of the slag tap body (6),

-wherein the central opening is limited by an annular reinforcement of the support plate (12),

-a ring (11) is welded on the outer circumference of the slag tap body (6), at which ring a horizontal annular plate (18) is in turn welded gas-tight, wherein the outer diameter of the annular plate (18) is greater than the inner diameter of the annular reinforcement of the bearing plate (12),

the annular plate (18) is connected to the annular reinforcement of the support plate (12) by means of a seal (10), and

-an annular plate (8) flexibly formed in the vertical direction closes an annular gap between the slag discharge body (6) and the cooling screen (2).

3. The entrained-flow reactor according to claim 2, characterized in that the annular reinforcement of the support plate (12) is formed by a support ring.

4. The entrained-flow reactor according to claim 2, characterized in that the collectors (7) for the cooling water feed and discharge channels of the cooling screen (2) and the slag tap body (6) are arranged in the annular space (16) above the support plate (12) and are connected to the coils of the cooling screen (2) and the slag tap body (6) by connecting pipes in the annular space (16), wherein the collectors (7) are each connected to a cooling system outside the reactor by a pipe feedthrough in the reactor wall (1).

5. The entrained-flow reactor according to claim 2, characterized in that the cooling screen (2) is supported at the reactor inner wall above the support plate (12) by means of at least three adjustable supports, wherein the supports comprise height adjustment means (4) for compensating length deviations and position deviations of the cooling screen (2) and for adjusting the height of the cooling screen (2) for installation purposes.

6. The entrained-flow reactor according to claim 2, characterized in that all other feed channels or connections for the cooling screen (2) and for the slag tap body (6) are likewise arranged in the annular space (16) in the inerted region above the support plate (12).