The invention relates to a compact burner for the pressurized gasification of pulverized fuel dust for producing synthesis gas.
In reactors for the entrained-flow gasification of pulverized fuel dust under elevated pressure to produce synthesis gas, pilot burners and main burners that are water-cooled several times on the reaction chamber side are used for supplying all the media. The water cooling processes are provided by pressure chambers, which present toward the reaction chamber an enlarged contact surface for the burner flame and the hot gases from the reactor. Mainly due to start-up and shutdown operations, the burner tip on the reaction chamber side has a limited service life. At the same time, particularly the burner cooling parts that are operated with cooling water and formed as closed pressure chambers require a high maintenance effort with regard to the recurring burner repairs. The various media to be supplied, such as for example fuel gas, pulverized fuel dust and oxidizing agent, have different temperatures and require structurally complex measures (e.g. corrugated expansion joints) for accommodating the different expansions of the burner channel walls.
A combined pulverized-coal burner with integrated pilot burner is known from DE 102007040890.
A gasification nozzle is known from CN2688677Y, wherein a sliding seal for compensating length changes is arranged at the joint between an inner spray tube and an outer spray tube.
The invention addresses the problem of providing a burner for the pressurized gasification of pulverized fuel dust for producing synthesis gas of which the burner tip achieves lifetimes comparable to conventional liquid-cooled burner tips without a cooling liquid being supplied.
The problem is solved by a burner having the features of the independent claim.
The cooling of the burner nozzles by means of complex, water-cooled, closed pressure parts is replaced by operating-media-cooled nozzles which are structurally designed accordingly.
The plant-related expenditure required for the existing water-cooling processes of the burner tip can be saved.
The burner nozzle parts are constructed in layers by means of generative processes and thereby largely produced in a finished state.
The process implemented for the layered construction uses a metallic powder, which is partially melted by means of a laser beam, at the end of which process the excess powder is removed and finally the desired component contour can be removed.
The generative manufacturing process is the SLM process (Selective Laser Melting).
Compared with the existing machining manufacturing process from forged parts, the production expenditure for the burner nozzles is lowered by more than 80%.
By using the laser melting process as the production process for the nozzle parts, it is possible to make contours of a satisfactory quality that cannot be created, or only with great difficulty, by conventional methods, such as for example narrow media channels or the temperature sensor channel, which is approx. 0.7 mm in size and follows the kinked nozzle contour.
By introducing temperature sensors at the burner nozzle parts in a position that is relatively protected in normal operation, conclusions can be drawn regarding the process conditions at the burner tip and the state of wear.
In addition to being cooled well by the operating media, the design of thin-walled nozzle parts results in optimization of the mixing of the reacting media and thus of the conversion of fuel and oxidizing agent.
For the purpose of adjusting to changing fuels, the adaptation of the swirl of the oxidizing agent is advantageous, this being achieved here by the introduction of a dividing wall into the oxidizing-agent channel. Here the medium can be fed to the burner tip in an axially non-swirled state in one channel and in a swirled state by means of guide plates or vanes in another channel. The quantity control of the two partial flows allows the desired resulting swirl to be set at the burner nozzle.
The use of sliding guides with sealing at the nozzles between the media alleviates the components of stresses caused by obstructed thermal expansion and eliminates the expenditure for additional measures such as expansion compensators in the media-channel walls.
Changing the nozzle during maintenance is simplified to a large extent by conventional welding without pressure tests.
There is no need for compliance with the technical regulations for pressure vessel construction, which consequently gives rise to a cost reduction for new construction and repair of the burner.
Advantageous developments of the invention are given in the subclaims.
The invention is explained in more detail below as an exemplary embodiment, to the extent necessary for comprehension, on the basis of figures, in which:
Identical elements are denoted by identical designations in the figures.
In
Using the SLM manufacturing process for the nozzles makes it possible to produce with sufficient accuracy and sufficient surface quality very narrow, in particular also kinked, channels, such as at the pilot burner nozzle (2), of a kind that cannot be produced conventionally, or only with very great effort. The arrangement of an integrated swirl plate (9) results, on the one hand, in an improvement of the function of the burner and, on the other, in a lengthening of the lifetime of the nozzle through good cooling by using the media.
Furthermore, in the nozzle there may be arranged close to the burner tip, a sensor (10) for temperature monitoring, which allows conclusions to be drawn, both regarding the thermal load and the state of wear of the burner and also regarding the current operating state of the gasification reactor (
As a further exemplary embodiment, the introduction of a dividing wall (12) into the oxidizing-agent channel of the main burner is shown in
Number | Date | Country | Kind |
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102014218219.0 | Sep 2014 | DE | national |
This application is the US National Stage of International Application No. PCT/EP2015/069412 filed Aug. 25, 2015, and claims the benefit thereof. The International Application claims the benefit of German Application No. DE 102014218219.0 filed Sep. 11, 2014. All of the applications are incorporated by reference herein in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/069412 | 8/25/2015 | WO | 00 |