DD145181A3 - REACTOR FOR GAS GENERATION BY PARTIAL OXIDATION UNDER INCREASED PRESSURE - Google Patents

Description

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!Vain

Reactor for gas production by partial oxidation

Field of application of the invention

The invention relates to a reactor for producing CO and jHp-containing gases by partial oxidation dust ·

shaped or liquid, in particular ash-containing fuels with a free-oxygen-containing gasification agent at high temperatures and elevated.

Print*

Characteristic of the known technical solutions In the case of gas generation from dusty or liquid fuels by partial oxidation, the fuel reacts with an oxygen-containing gasification agent in a flame reaction. Depending on the fuel and the area of application of the gas, final reactions of the reaction occur between 12oo and 16oo ⁰ C, while in the plamme itself temperatures above 2OOo ⁰ G are reached. If ash-containing fuels are used, the mineral residues of the partial oxidation process will be in a molten state *

The flame reaction takes place in, a refractory, usually rotationally symmetric reaction space, wherein the known methods differ by the arrangement of the burner and the discharge of the hot, raw gas generated and the slag.

Gas generating processes of the type mentioned are frequently operated under elevated pressure, for example at 3 MPa. Reactors for such a printing process, for example, consist of an outer pressure vessel in the interior of which the actual reaction space is located _? whose profile is formed by walls of water-cooled pipes j. The pipe walls are provided on the side facing the planks with a layer of refractory ramming mass, for example on the basis of silicon carbide. The adhesion of the ramming mass to the tubes is achieved by pins of, for example, 10 mm in diameter and 1 mm in height, which are welded to the tube surface and protrude into the ramming mass layer. The layer thickness of the ramming mass is dimensioned so that the surface temperature is lower than the solidification temperature of the obtained during Partialoxydationsprozess slag. During operation of the reactor, a further layer of solidified slag, which are in a pasty zone and finally a running liquid slag film is _E, the cooling of the pipe wall can with pressurized water with a temperature below the boiling point or boiling water forms .Therefore on the surface of the packing material ,

The tube wall must protect the outer pressure jacket against overheating by radiation and Eonvektionsströmungen safely. Therefore, a thermal insulating layer of refractory material is often provided between the pipe wall and the outer pressure jacket. By

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the masonry and expansion joints, by inevitable cracks and by the porosity of the refractory material, this insulating layer inevitably has a considerable and spatially indefinable gas permeability. If the reactor, as usual, ignited under approximately atmospheric pressure and brought to full operating pressure in the hot state, so with rapid pressure increase such large stray gas streams may occur that the pressure jacket is locally overheated. The same dangers are to be expected if high pressure differences or partial slagging lead to larger pressure differences within the reaction space or in the raw gas outlet channel.

As a rule, although the cooled pipe wall can be operated at temperatures above the Wasserdampftaupunktes, but the temperature of the pressure jacket remains below this dew point. The gas permeability of the insulating layer allows the condensation of steam on the pressure jacket and favors corrosion.

Bs has been proposed, the., Masonry: / or, defi-

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flushed pores in the masonry with irrigated gas. The at least in the long term not locally definable gas permeability of the masonry limits even with large Spülgasmeiigen the effect of such a measure to a minimum "There are embodiments of reactors with cooled pipe wall constructions known _? -.bei which the individual, juxtaposed tubes are connected by welded, running over the entire pipe length webs. The RoA ^ and is thus gas-tight. The connection between the reaction space and the space between the pipe wall and the pressure jacket, which is required for pressure equalization, is limited to one or a few controllable openings which can be effectively controlled by inert gas purging. "

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Such a solution leads to a very rigid tube wall construction, the further advantage of which lies in simpler mounting constructions and easier assembly. However, the rigidity of the tube wall can be traced. suffers significant disadvantage:

During start-up and shut-down and load changes is unavoidable that ramming mass and solidified slag stretch or shrink. The rigid, welded tube wall construction can this Längenände-. ments do not follow, so that it often comes to flaking the ramming mass from the pipe wall. The much higher thermal load of the uncovered parts of the pipe wall can lead to a risk of local overheating.

Object of the invention

The object of the invention is a reactor for gas production by partial oxidation of dusty or liquid, ash-containing fuels under pressure, the pressure jacket is reliably shielded against overheating and exposure to raw gas and allows long travel times. ·

Explanation of the essence of the invention

- The invention has for its object to propose a reactor for gas production by partial oxidation of powdery or liquid fuels under elevated pressure, the reaction chamber is formed by a water-cooled and reaction chamber side provided with ramming tube wall construction whose outer pressure jacket reliably and in all phases of operation against overheating and exposure the raw gas atmosphere is protected, the internals, in particular the Rohrwandkonstruktiori easy to mon-

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animals and dismantling and the particular in terms of the durability of the rammed earth lining in the reaction chamber long travel guaranteed

The solution according to the invention is characterized by the following features:

The forming the reaction space and on the side facing the reaction chamber and furnished with refractory ramming tube wall is surrounded at a distance usually from 1 to 5 cm from a gas-tight housing, wherein the space between the individual tubes of the pipe wall and the housing also with refractory ramming mass is filled.

On the inside of the housing webs are fixed, which divide this inner ir several sections and which protrude into the ramming mass. With these webs the purpose is pursued, despite the inevitable in the course of operation crack formation between ramming mass and the inside of the housing large-scale, to avoid stray currents of hot gas on the housing wall. According to the invention, these webs can also serve to fix the length of the pipe wall, without a rigid connection between these webs and the tubes of the pipe wall is brought about. The housing is housed within an outer pressure vessel. The "space between the jacket of the external pressure vessel and the housing is connected by one or more openings to the reaction space" within the housing, and one or more inlet ports shall be provided on the external pressure vessel for gas inert gas, with which the space between the external pressure vessel Pressure vessel and housing can be rinsed «.

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In a preferred embodiment of the invention for reactors with a standing, cylindrical Reaktionsramn, whose end faces are provided with axial openings for receiving the burner or * of Rohgas- and slag outlet, the cylindrical part of the tube wall consists of one or more parallel tubes, the one to a - or mehrgängigen helix are wound, and their Bin- and outlet ends for · the cooling medium through the housing and easily detachable, pressure-tight bushings of known construction by the outer pressure vessel are guided «The tubes are on the spiral axis facing side donated. According to the invention is on the inside of the. the tubular coil enveloping housing in at least one horizon helically and in the same pitch as the helix of the tube wall one or more webs attached, which protrude into the space between two adjacent pipe turns.

According to the invention, the length of a web corresponds to a full turn. The ends of the web are connected by a further, paraxial web whose outer edge is adapted to the outer profile of the coiled tubing, that is provided depending on the number of courses of the helix with one or more semicircular recesses whose radius and distance from the pipe diameter or the distance of the turns of the helix are adapted.

The space between the coiled tubing and the inside of the housing and., As known, the contoured the reaction chamber forming, donated side of the tube wall is provided with a refractory ramming mass, according to the invention forms the rammed mass pipe wall with the housing, preferably by welded joints between Housing and inlet and outlet ends of the tubes and by positive connection,

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a structural unit and can be introduced as a whole in the outer pressure vessel and mounted or removed after lots of pressure-tight feedthroughs for the pipe ends through the outer pressure vessel from this.

With the solution according to the invention, it is easily possible, with suitable dimensioning of the connection openings between the reaction space in the interior of the housing and the space between the outer pressure vessel and the housing to adjust the amount of inert purge gas so that at least Spülgasbedarf the entry of raw gas ± n prevents this gap becomes. Only r ä & phase, the pressure gradient in the reaction chamber during the start is vender depending on size of the free volume in the reaction chamber as far as to readjust the amount of inert gas that the transfer flow rate of the inert gas from the space in the interior of the Geliäuses constantly greater than zero remains.

In the solution according to the invention remains due to the distortion on a rigid connection between the individual pipes or pipe turns sufficient elastic Beschoxmbarkeit the pipe wall _y so that the individual tubes can yield thermal expansion and shrinkage of the coated in operation with a layer of solidified rope coatings layer of ramming mass and the risk of chipping off the ramming mass is substantially reduced. The inventive solution also allows a defined flushing the Imienwand the outer pressure vessel, sq ^ that thermal and. corrosive effects on the jacket of the pressure vessel by the raw gas can be avoided.

  embodiment

The invention will be explained with reference to an exemplary embodiment and with reference to FIG. 1 to FIG.

This shows Pig. 1 is a schematic representation of a reactor for the partial oxidation of dust-like fuels under elevated pressure, Pig. 2 a detail of the four-turn coiled tubing and Pigur 3 a detail section through the housing, coiled tubing and ramming mass coating and slag layers in the in Pig. 1 marked cutting direction AB »

Which for a pressure vcn 3 _? o MPa designed and for the gasification of lignite dust with about 1o # ash content by partial oxidation by means of technical oxygen particular reactor, Pig. 1, has a cylindrical reaction chamber whose end faces are provided with axial openings for receiving the burner or the Rohgasabzuges, and a two-part outer pressure vessel 1, consisting of the pressure vessel body 3 "and the connected by splashing cover 2, in its interior is the Actual reaction space 4, in which, at a final temperature of about 1400C and the above-mentioned pressure, technical oxygen and lignite dust in a plamme react with each other to form a gas containing CO and H.sub.2.

The supply of reactants via the burner insert 5, which also carries devices for ignition and temperature measurement in .Reaktionsraum. The crude gas produced occurs at a temperature of about 14oo ⁰ C together with the liquid slag in the triggering and cooling device 6, through which it leaves the reactor and is fed after separation of the slag for further processing.

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The reaction space is enclosed by a four-pass coiled tube formed of four tubes. For the sake of clarity, Pig. 1 only one gear of this helix is shown while Pig. 2 shows a perspective view of a section of this spiral formed by the four tubes. The tubes of the coil are on the side facing the reaction space with welded pins 23, as well as Pig. 3 shows in detail, provided.

The coiled tubing 7 is wrapped with a gas-tight housing 8, which is made in comparison to the jacket of the outer pressure vessel made of relatively thin sheet metal, The distance between the outside of the helix forming tubes and the housing is about 2cm _f The housing with the coiled tubing resting on trusses 9, which divert the load to the bottom of the pressure vessel 1.

For ease of installation, the housing is provided at the top with a lifting lug 1o for attaching hoists. The intermediate space 11 between the housing 8 and the jacket of the outer pressure vessel 1 is connected to the reaction space 4 via the annular gap 12 between the burner insert 5 and an upper opening of the housing. Another connection consists of the during operation, however, largely offset with slag lower annular gap 13 between a lower opening of the housing 8 and the triggering and cooling device 6 for the raw gas. With the nozzle 22 is given the opportunity to flush the gap 11 with nitrogen, which passes through the ringpaltfürmigen openings 12 and 13 in the reaction space. The upper and lower ends 15 of the tube spiral 7 forming tubes are easily detachable Einsehweiß-passages 14 through the bottom of the pressure vessel body 3.bzw. Cover 2 led to the outside and - in Pig. 1 not shown - with

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Cooling water supply and drainage connected. The water pressure in the cooling tubes is 4, ο MPa and is greater than the pressure in the reaction space. The temperature of the incoming water is 16o ⁰ C and is higher than the dew point of the raw gas, which is approximately at 15o ⁰ C.

The inside of the housing 8 is distributed over the height provided with a plurality of helical and with the same pitch as the coiled tubing 7 webs 16 which protrude approximately up to the level of the tube axis in the space between two adjacent pipe turns of Wendejl. The length of a web 16 corresponds to a full Schraubenwindung. The vertically superimposed ends of each web 16 are, as Fig. 3 illustrates, connected to a further, vertically arranged'Steg 17 whose outer edge is provided with four semicircular cutouts 18 whose radius and distance from the pipe diameter and the winding spacing of four Pipes existing coiled tubing 7 correspond. The vertical web 17 thus engages comb-like in the coiled tubing 7.

The coiled tubing 7 is embedded in a refractory ramming mass 19 based on silicon carbide, which both fills the intermediate space 24 between coiled tubing 7 and the wall of the housing 8 and also covers the tubular surface facing the reaction space 4. The thickness of the tube covering the inside of the layer is selected with about 2o mm so that the temperature at the surface of the ramming mass 19 is smaller than the lying at about 11oo ⁰ C solidification temperature of the liquid slag. Upon impact of liquid slag on the wall, a solidified slag layer forms above the refractory ramming mass 19, which finally flows into a liquid

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Slag 21 passes, as Pig, 3 shows. With regard to the strength of the solid and liquid slag layer, an equilibrium state arises in operation, which is dependent on temperature, heat transfer conditions and performance of the flame reaction in the reaction chamber 4 on the one hand and cooling intensity and heat conduction in the ramming mass 19 and the cooling tubes on the other. »

Ramming mass 19 and solidified slag layer 2o form a relatively rigid and rigid bandage and are subject to thermal expansion and shrinkage especially during startup and shutdown processes as well as changes in the operating condition. With the chosen solution, however, sufficiently high flexibility of the coiled tubing 7 is given so that it can meet the thermal movements of ramming mass and slag. In this way, the risk of chipping ramming mass is largely reduced. In contrast, it is inevitable that cracks between ramming mass 19 and wall of the housing 8 occur in the course of operation. The protruding into the ramming mass 19 webs 16 and vertical webs 17 but prevent a large-scale flow behind the ramming mass 19 by hot gases, so that overheating of the housing 8 can not be done. The housing 8 is set to a temperature which corresponds approximately to the mean coolant temperature in the coiled tubing 7 (about 18o ⁰ C). This avoids the condensation of water vapor. The Zv / ischenraum 11 between the outer pressure vessel 1 and the housing 8 via the nozzle 22 supplied amount of nitrogen is in Kormalbetrieb. so dimensioned that the speed in the annular gap 12 and lower annular gap 13 is about. o, 2 m / s, only in operating phases in which the

Pressure in the reaction chamber 4 is increased, the reduced to normal pressure nitrogen flow rate is increased to a value which is slightly greater than the value ρ ₁

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where V is the volume of the gap 11, the pressure increase in the unit time and P is the normal pressure.

The jacket of the outer pressure vessel 1 therefore prevails inside a nitrogen atmosphere and the condensation of water vapor from the raw gas is avoided. To limit the temperature of the outer pressure vessel 1 to values that exclude annoyances of the operator, the inside of the outer pressure vessel 1 is still with a in Pig. 1 thin insulation not shown provided.

Claims (5)

Erfindungsansprueh , Reactor for partial oxidation of dusty and / or
or liquid fuels containing ash
increased pressure, the reaction space of a
coated with refractory ramming mass, flow-cooled pipe wall, wherein the individual tubes of the tube wall against each other are elastically movable, characterized in that the tube wall is surrounded at a short distance from a gas-tight housing (8), which in turn is housed within an outer pressure vessel (1) , wherein the resulting from the distance between the housing (8) and the tubes of the pipe wall gap (24) with a refractory ramming mass
(19) is filled, on the inside of the housing (8) webs (16) are fixed, which divide this inside into several sections and which protrude into the intermediate space (24) filling ramming mass (19), the reaction space (4) within of the housing (8) with the intermediate space (11) between the outer pressure vessel (1) and housing (8) by a
or more openings is connected and said gap (11) between the outer pressure vessel (1) and housing (8) in a known manner with at least one nozzle (22) for supplying inert
Purge gas is provided. · • \ r \ ι / ί Ι λ , 2. Reactor nach.Punkt 1, characterized in that the cylindrical part of the pipe wall has the Porm a catchy or multi-start helix. 3. Reactor according to item 1 and 2, characterized in that on the inside of the housing (8) in one or more horizons helically and with the same pitch as the coiled tubing (7) of the tube wall one or more webs (16) are attached which protrude into the intermediate space (24) between two adjacent pipe turns » 4. Reactor according to item 3, characterized in that the length of a web (16) corresponds to a full turn and that its ends by a further, on the housing (.8) fixed, paraxial 'Web (17) are connected, whose outer edge has one or more halberer isiform cutouts, wherein the radius and the distance of the cutouts of the tube wall are adapted. 5. Reactor according to item 1 to 4, characterized in that the ramming mass (19) provided with the tube wall and the housing (8) are mounted as a structural unit in the outer pressure vessel (1) mountable « Pages drawings