KR102050617B1

KR102050617B1 - A burner for the gasification of a solid fuel

Info

Publication number: KR102050617B1
Application number: KR1020147030524A
Authority: KR
Inventors: 요하네스 헤르마누스 마리아 디셀호르스트
Original assignee: 에어 프로덕츠 앤드 케미칼스, 인코오포레이티드
Priority date: 2012-04-02
Filing date: 2013-04-02
Publication date: 2019-11-29
Also published as: WO2013150008A1; CN202835334U; KR20150001791A; CN104204155A; CN104204155B; EP2834327B1; EP2834327A1

Abstract

The present invention relates to a burner (1) for gasification of solid fuel, which burner front part (2) having an annular opening (13) for discharging solid fuel and a central opening for discharging oxygen containing gas ( 11),
The fuel discharge opening 13 is in fluid communication with the central passage portion 5 and the opening 11 for discharging the oxygen containing gas is an annular passage portion 6 for oxygen passage coaxially located with the central passage portion 5. In fluid communication. The central passage part 5 has a downstream part 6 and the diameter of the central passage part 5 increases over the first length 7 and then to the second length 8, which terminates at the burner front part 2. Decreases over time. Inside the downstream part 6, the hollow member 9 is positioned to be closed at one end 10 and to have an opening 11 at or near the burner front part 2. The hollow member 9 has an increasing diameter and decreasing diameter aligned with the increasing diameter and decreasing diameter of the central passage portion 5 to form the annular passage 12. The hollow member 9 is in fluid communication with the annular passage 6 for the oxygen containing gas by one or more connecting conduits 14.

Description

BURNER FOR THE GASIFICATION OF A SOLID FUEL}

The present invention relates to a burner for gasification of a solid fuel. The burner is a finely divided solid fuel, such as nitrogen gas and / or carried by a gas carrier, for example to produce an pressurized synthesis gas, fuel gas or reducing gas using an oxygen-comprising gas. Or particularly suitable for use in the gasification of carbonaceous fuels such as pulverized coal carried by a gas carrier such as carbon dioxide.

Gasification of a solid carbonaceous fuel is obtained by reaction of oxygen and fuel. The fuel mainly contains carbon and hydrogen as combustible components. The gas-carried finely divided carbonaceous fuel and the oxygen containing gas pass into the reactor through separate channels in the burner at relatively high speeds. The flame in the reactor is maintained such that the fuel reacts with oxygen in the oxygen-comprising gas at temperatures above 1300 ° C. to form primarily carbon monoxide and hydrogen.

Various burner configurations have been proposed in the prior art. EP-A-328794 has finely divided coal supplied to the burner front via a central channel disposed along the longitudinal axis of the burner, and oxygen-containing gas is passed through at least one annular channel surrounding the central channel. The burners supplied are described. Oxygen is directed in the flow of coal at the burner front.

EP-A-130630 describes a burner in which the oxygen-containing gas is discharged from the central channel at high speed and the oxygen-containing gas is discharged from the annular outlet at low speed in the burner front part. Solid fuel exits from a plurality of outlet openings located between the central and annular oxygen outlet openings. According to this publication, the external low speed oxygen stream serves to protect the burner against overheating due to the inhalation of hot gases. The publication discloses that if the burner is used for large throughputs, the outlet openings for the solid fuel preferably do not have an annular shape. It is said that such a configuration does not cause proper contact of oxygen with all solid fuel particles.

Burner types according to EP-A-328794 have been very successfully used commercially. However, at high throughput the heat-flow rate to the burner front increases to such values that burner life can be very short.

EP-A-130630 addresses the problem of heat flux to the burner front by applying a low-speed oxygen shield around the flame. A disadvantage of the burner according to EP-A-130630 is that for high throughputs solid fuel passes through the individual channels of the burner front, which can lead to corrosion problems. Another problem is the complexity of the construction due to the fact that one metal piece having a plurality of channels for the solid fuel and the oxygen containing gas needs to be manufactured. In addition, the heat flux to the burner front can still be very high due to the synthesis gas / oxygen flame.

The following burners aim to provide burners that can be used for high throughputs and do not have the disadvantages of burners of the prior art:

The burner for gasifying the solid fuel includes a burner front portion having an opening for discharging the solid fuel and one or more openings for discharging the oxygenous gas, wherein the opening for discharging the solid fuel is in fluid communication with the central passageway. The opening for discharging the oxygen containing gas is in fluid communication with the annular passage for passage of oxygen,

The central passage portion has a downstream portion and the diameter of the central passage portion increases over the first length and then decreases over the second length ending in the burner front and inside the downstream portion of the central passage, the hollow member is closed at one end and the burner The hollow member is positioned to have an opening in the front portion, and the hollow member, in an inwardly directed annular opening for discharging the solid fuel, increases and decreases the diameter of the central passageway to form an annular passageway for the solid fuel that terminates in the burner front portion. Having increasing diameter and decreasing diameter aligned with the diameter;

The hollow member is in fluid communication with the annular passageway for the oxygen containing gas by one or more connecting conduits and the opening of the hollow member forms at least part of the opening for discharging the oxygen containing gas.

The invention also relates to a process for producing a mixture comprising hydrogen and carbon monoxide by gasification of a solid fuel using such a burner, wherein the oxygen containing gas passes through a passage for the oxygen containing gas, Carrier gas passes through the central passage and gasification occurs at the burner front.

Applicants have found that in contrast to the implications of EP-A-130630, a burner having an annular opening for a solid fuel can be provided for high throughput operation. Sufficient contact with the solid fuel is achieved by directing all oxygen through one or more openings for the oxygen containing gas. Detailed computer simulations predict that the flame will be lifted somewhat from the burner front. This significantly reduces the heat flux to the burner front and thereby prolongs the life of the rim separating the burner front and annular passages for solid fuel and one or more openings for evacuating oxygen containing gas.

The burner according to the invention does not have an external annular outlet for discharging the oxygen containing gas at a lower rate as in the burner according to EP-A-130630. Due to the alignment in the dimensions of the hollow member and the central passageway, the flow path of the solid fuel results in limiting corrosion.

The term 'oxygen-comprising gas' as used herein refers to a gas comprising free oxygen, O ₂ , and air, oxygen-charged air (ie, at least 21 mol% oxygen) and also substantially pure oxygen (ie , At least about 95 mole% oxygen) and the remainder include gases generally present in air, such as nitrogen, and / or rare gases.

As used herein, the term 'solid carbonaceous fuel' refers to a variety of, gas transported, combustible materials and coal, coke from coal, coal liquefaction residues, petroleum coke, soot, biomass, and oil shale, tar sands And their mixtures from the group of particulate solids derived from pitch. Coal can be of any type, including lignite, sub-bituminous, bituminous and anthracite. Solid carbonaceous fuels are preferably polished to a particle size at least about 90% by weight of the material is less than 90 microns and the moisture content is less than about 5% by weight. The solid fuel is mixed with a carrier gas, preferably nitrogen or carbon dioxide, and fed to the burner.

The term high capacity burner as used herein is intended to include a process in which solids are ejected from the annular opening at least 3 kg / sec. The width of the annular opening of such a high capacity burner is preferably at least 4 mm. The preferred velocity of the solids when exiting from the annular opening is 5 to 15 m / s.

The opening for the oxygen containing gas may be a single central opening at the burner front or may be configured differently, for example arranged at a distance upstream of the burner front. For non-vertical burners, especially for horizontal burners, such a retracted opening reduces the risk of blockage by slag flowing down from the burner front.

In further specific embodiments, the opening may comprise a plurality of openings, which may be coaxial, for example. Such an arrangement may include, for example, a central opening at the end of the low speed conduit, and an annular opening at the end of the high speed conduit, which is surrounded by an inwardly directed annular opening for discharging the solid fuel. In such an arrangement, the mixing of oxygen and fuel is completed at a substantially shorter distance from the burner front. Optionally, the longitudinal axis of the central conduit may be offset from the longitudinal axis of the annular conduit, for example, the central conduit may be offset downward relative to the center of the annular channel. For horizontal burners, this compensates for the influence of gravity to make the solid fuel outflow uniform. In such a burner arrangement the central opening can withdraw the oxygen containing gas at a speed of, for example, 10 to 30 m / s, while the annular opening around the central opening can draw oxygen containing gas at a speed of 30 to 100 m / s. And the fuel discharged from the annular opening is discharged at a speed of 5 to 15 m / s.

In a further specific embodiment, the opening for the oxygen containing gas may include one or more openings having a longitudinal axis at a distance from the longitudinal axis of the fuel outlet opening. More specifically, the opening may be at a distance below the central point of the fuel outlet opening. For horizontal burners, this compensates for the effects of gravity to make the fuel outflow uniform.

The burners are particularly suitable for carrying out a process for producing a mixture of hydrogen and carbon monoxide by gasification of solid fuels, with oxygen containing gas passing through the passage, solid fuel and carrier gas passing through the central passage and gasification in front of the burner Occurs in wealth.

1 shows a longitudinal section of the frontal portion of a first exemplary embodiment of a burner;
FIG. 2 shows a cross-section section AA ′ of the burner of FIG. 1;
3 shows a longitudinal section of the front part of the second exemplary embodiment of the burner;
4 shows a longitudinal section of the frontal portion of a third exemplary embodiment of a burner.

1 shows a longitudinal section of the front part of the burner 1. The burner 1 has a burner front part 2 having an opening 13 for discharging solid fuel and a single central opening 11 for discharging an oxygen containing gas. The opening 13 for discharging the solid fuel is in fluid communication with the central passage part 5. The passage 6 is located coaxially with the central passage portion 5.

The central passage part 5 has a downstream portion and the diameter of the central passage part 5 increases over the first length 7 and then decreases over the second length 8 terminating at the burner front part 2. . Inside the downstream part 6 of the central passage part, the hollow member 9 is positioned with the opening 11 closed at one end 10 and spaced upstream from the burner front part 2. The hollow member 9 has a central passage part 5 to form an annular passage 12 for the solid fuel which terminates near the burner front part 2 in the inwardly directed annular opening 13 for discharging the solid fuel. ) Increasing diameter and decreasing diameter aligned with increasing diameter and decreasing diameter. Alignment in diameter can be selected to change the flow direction only gradually to limit corrosion.

The hollow member 9 preferably has an increasing diameter 15 inside and a decreasing diameter 16 inside aligned with the increasing and decreasing diameter of the hollow member 9. This defines a hollow space in the hollow member having a conical shaped portion and a cut conical shaped portion. The hollow member 9 is in fluid communication with the annular passage 6 for the oxygen containing gas by one or more connecting conduits 14. The connecting conduits 14 are also spacers that keep the hollow member 9 positioned in the central passage 5. The configuration of the conduits 14 may be present such that when used the vortex is imparted to the flow of solids or to the oxygen containing gas or both. In the exemplary embodiment shown, the connecting conduits 14 have a discharge opening 17 located in the diverging part of the hollow member 9 having a diameter 15 and otherwise in the conical part. The outlet openings 17 are of an ellipsoid shape, with the longer dimension aligned with the axis of the burner. In the embodiment shown, the number of openings 14 is three. Less or more openings 14 may also be used if desired.

Fig. 1 also shows the opening 11 of the hollow member at its cut cone-shaped end, which is an opening for discharging an oxygen containing gas. The opening 11 for discharging the oxygen containing gas is thus in fluid communication with the annular passage part 6 for the passage of the oxygen containing gas via the hollow member 9 and the connecting conduits 14.

The downstream end of the hollow member 9 forms a rim 25. The rim 25 and the opening 11 are present at a distance upstream of the burner front part 2. This reduces fragments of syngas and dilute coal before mixing with oxygen and risks of blockage by liquid slag flowing down from the burner front 2, especially when the burners are not vertical, for example horizontal. To reduce the heat flux towards the rim 25 after the burner shuts down, for example.

The dimensions and shape of the hollow member 9 can be selected such that the oxygen containing gas is discharged from its opening 11 in a flow that is evenly dispersed. Preferably the velocity of the oxygen containing gas when exiting from this opening is 30 to 90 m / s. The shape of the hollow member comprises a sharp conical end and a cut conical end towards the burner front part 2, both parts being connected directly or selectively through the tubular part. The angle made by the slopes of the top of the conical end 10 is preferably 5 to 35 °. This angle is preferably not too large to limit corrosion at the point where the flow of solids debouched from the central passage 5 to the annular passage 12. The shape of the truncated conical portion is preferably selected such that the angle between the final outflow direction of the inwardly directed annular opening 13 for discharging the solid fuel and the axis of the burner 1 is between 5 and 35 °.

Preferably the width of the rim 25 of the hollow member 9 separating the opening 13 for discharging the solid fuel from the opening 11 for discharging the oxygen-containing gas is 0.5 to 3 mm. The angle as formed by the outflow direction of the inwardly directed annular opening 13 for discharging the solid fuel and the axis of the burner 1 is preferably 5 to 35 °. It has been found that within this range an optimum contact between the oxygen containing gas and the fuel is achieved while also sufficient lifting of the flame and thus a reduction in the heat flux.

The burner of FIG. 1 also has a preferred annular passage section 19 for cooling water located around the annular passage section 6. Around the passage 19 there is an annular passage 20 for return cooling water. Suitably the passages 6, 19 and 20 have a central opening for the central passage 5, a plurality of openings for the passage of fresh coolant from the passage 19 to the cooling jacket 23. A plurality of openings 22 for passage of cooling water used from the cooling jacket 23 to the passage portion 20 from the cooling jacket 23 are terminated in the provided connection block 21. The presence of the connecting block 21 is advantageous because it makes it possible to simply replace the damaged hollow member 9 with another. The cut conical part of the hollow member can be removed by cutting the cut conical wall part 26 and the cooling jacket 23 of the central passage part 5 from the connecting block 21. The connecting block 21 is suitably positioned at the point where the diameter of the central passage 5 is reversed from increasing diameter to decreasing diameter to allow simple removal as described herein.

The cooling jacket 23 is preferably a cooling jacket as described in the aforementioned EP-A-328794 or as described in CN-A-101363624. Such a cooling jacket 23 has double walls 28, 29 which define the outside of the burner section starting at the connecting block 21 and terminating at the burner front part 2. Double walls 28, 29 are spaced apart by one or more baffles 30 that define a portion of burner front part 2 and a flow path for the coolant surrounding the burner section. The coolant enters the burner front part 2 through the opening 32 from the coolant compartment 31 defined by the wall 26 and the wall 29 of the central passage part 5. The coolant compartment 31 is in fluid communication with the passageway 19 through the openings 24.

The end of the burner 1 with supply connections for oxygen containing gas, solid fuel, fresh and used cooling water is omitted in FIG. 1. The configuration as described in CN-A-101363622 can be suitably used for this purpose.

The reference numerals used in FIG. 2 have the same meaning as described above. 2 also shows the outer wall 27 of the annular passageway 20. 2 shows an embodiment with three openings 17. In FIG. 1 only one connecting conduit 14 and one opening 17 of the three openings are shown for clarity.

FIG. 3 shows a horizontally arranged burner 40 which is about the same size as the burner 1 of FIG. 1. Reference numerals used in FIG. 3 have the same meanings as described above. The main difference from the burner 1 in FIG. 1 is that the hollow member 9 has a longitudinal axis A at a distance X below the longitudinal axis B of the central passage part 5. As a result of the radial width of the annular passage 12 being larger at the upper side than at the lower side, the volumetric outflow will therefore be larger at the upper side of the annular fuel outlet opening 13. This compensates for the fact that the coal density at the upper part of the fuel outlet 13 is lower than the coal density at the lower part of the fuel outlet 13.

In the embodiment of FIG. 3, the rim 25 and the opening 11 are in the burner front part 2. In an alternative embodiment, the rim 25 and the opening 11 can be present at a distance upstream of the burner front part 2 similarly to the embodiment of FIG. 1.

FIG. 4 shows a horizontal burner 50 of the same size as burner 1 of FIG. 1 and burner 40 of FIG. 3. The reference numerals used in FIG. 4 have the same meaning as described above. In the embodiment of FIG. 4, the opening 11 comprises a plurality of coaxial openings comprising a central opening 11 for discharging an oxygen containing gas, which central opening 11 is downstream of the low speed conduit 51. And an annular opening 52 directed inwardly at the downstream end of the high speed conduit 53 and the opening 60 at the end. The annular opening 52 is surrounded by an inwardly directed annular opening 13 for discharging the solid fuel. The second vertical connecting block 54 divides the interior of the hollow member 9 into the upstream side 55 and the downstream side 56. The substantially cut conical wall 57 extends from the second connecting block into the opening 11. The cut conical wall 57 runs substantially parallel to the wall of the hollow member 9.

The second connecting block 54 is provided with a central opening 58 which provides an open connection between the central passage 5 and the interior of the cut conical wall 57. The interior of the conical wall 57 cut in this way defines a first oxygen supply conduit 51.

The second connecting block 54 also has openings 59 of circular alignment which provide an open connection between the central annular space 5 and the downstream annular space between the cut conical wall 57 and the hollow member 9. This is provided. This annular space defines the second oxygen supply conduit 52. The dimensions of the hollow member 9, the cut conical wall 57 and the openings 58, 59 in the second connecting block 54 are high-speed oxygen flow in the annular conduit 53 and low-speed oxygen in the central conduit 51. Dimensioned to obtain flow. This reduces the distance between the burner front part 2 and the downstream point where the mixing between oxygen and fuel is completed.

In the embodiment of FIG. 4 the longitudinal axis of the cut conical wall substantially coincides with the longitudinal axis of the hollow member 9 and the burner 50. In an alternative embodiment, the longitudinal axis of the cut conical wall 57 may be offset from the longitudinal axis of the hollow member 9 and / or offset from the longitudinal axis of the burner 50. Especially for non-vertical, eg horizontal burners, the downwardly offset arrangement of the truncated conical wall 57 can contribute to compensating for nonuniformity of density dispersion in the annular passageway 52.

Claims

As a burner for gasification of solid fuel,
A burner front having an opening for discharging solid fuel, and
One or more openings for evacuating an oxygen containing gas,
The opening for discharging the solid fuel is in fluid communication with a central passage portion,
Said at least one opening for discharging said oxygen containing gas is in fluid communication with an annular passageway for passage of oxygen,
The central passageway has a downstream portion and the diameter of the central passageway increases over a first length and then decreases over a second length terminating at the burner front,
Inside the downstream portion of the central passage portion a hollow member is positioned to close at one end and have an opening at the burner front portion, the hollow member in the inwardly directed annular opening for discharging the solid fuel, the burner front side Having an increasing diameter and decreasing diameter aligned with the increasing and decreasing diameter of the central passage portion to form an annular passageway for the solid fuel terminated in the portion,
The hollow member is in fluid communication with the annular passageway for the oxygen containing gas by one or more connecting conduits,
The opening of the hollow member forms the opening for discharging the oxygen containing gas,
The opening for discharging the oxygen containing gas comprises a plurality of openings, the plurality of openings being coaxial, comprising a central opening at the end of the low speed conduit and an annular opening at the end of the high speed conduit, the annular opening being A burner for gasification of solid fuel, surrounded by the inwardly directed annular opening for discharging the solid fuel.

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