KR20030067706A - Device for injecting fine-grained solid particles into a gaseous stream - Google Patents

Abstract

An apparatus 14 for injecting finely divided solid particles into a gas flow is shown, wherein the finely divided solid particles are conveyed to the device 14 in the form of compressed air flow. The device 14 comprises an annular gap 40 through which compressed air flow enters into the gas flow. The annular gap 40 is disposed inside the gas flow 12 such that the velocity vector 46 of the solid particles is essentially perpendicular to the velocity vector 48 of the gas flow 12 upon discharge from the annular gap. An injection jet 50 which expands in an umbrella in the direction of gas flow 12 is produced by the sum of the vectors 46, 48.

Description

DEVICE FOR INJECTING FINE-GRAINED SOLID PARTICLES INTO A GASEOUS STREAM}

In general, it is known that the flow of gas can be treated by the injection of finely divided solid particles. For example, in an ironworks steel mill, finely powdered lignite coke is injected into the exhaust gas flow exiting the furnace. Porous lignite coke particles absorb contaminants contained in the exhaust gas flow. It can then be separated out of the filter device and treated in a relatively less problematic way. In this case, the injection of lignite coke takes place in a gas exhaust pipe having a diameter of the order of several meters. There is a laminar gas flow inside the pipe, and the internal gas velocity reaches up to 100 km. The injection amount of lignite coke generally needs to be relatively small so as not to overload the filter device (for example, about 0.1 to 1 kg of lignite coke per 1000 Nm3 of exhaust gas). Recently, however, it is required that the finely divided lignite coke particles be distributed as uniformly as possible over the entire cross section of the pipe.

To date, an injection lance is known which injects kaltan coke suspended in the conveying gas into the pipe at several points, where the injection can occur in the same flow as the gas flow direction or in a transverse flow. have. In this regard, a relatively expensive dispensing device is first required to divide the compressed air flow which is susceptible to friction between multiple windows. It will also be appreciated that it is not possible to prevent the formation of strands of kaltan coke sprayed in the laminar gas flow inside the pipe. This means, among other things, that some gas does not come into contact with the injected lignite coke at all.

The present invention relates to an apparatus for injecting finely divided solid particles into a gas flow.

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a longitudinal sectional view of a pipe for gas flow with a device according to the invention for the injection of finely divided solid particles into a gas flow;

It is therefore an object of the present invention to propose a simple device for injecting micropowdered solid particles into a gas stream which ensures an improved distribution of solid particles in the gas flow.

In the apparatus according to the invention for injecting the finely divided solid particles into the gas flow, the finely divided solid particles are conveyed in the form of pneumatic flow as in known injection lances. However, the device according to the invention comprises an annular gap, through which the compressed air flow is injected to intersect the gas flow. This annular gap is disposed inside the gas flow such that the solid particle velocity vector inside the compressed air flow is essentially perpendicular to the velocity vector of the gas flow upon discharge from the annular gap. Injected jets sprayed in an umbrella shape in the direction of gas flow are generated by the superimposition of the velocity vectors. By such jet jet umbrella spraying around the annular gap, such a simple device enables a more improved distribution of solid particles in the gas flow compared to having a known injection window.

In most cases, if the annular gap exhibits a rotationally symmetrical structure, there is an advantage that the distribution of solid particles is essentially similar to the rotationally symmetrical type. However, it cannot be overlooked that in special cases it may be beneficial to design the annular gap in such a way that the distribution of solid particles is not rotationally symmetric. For example, an annular gap may be reduced or blocked in each sector to reduce or block the discharge of compressed air flow inside the angular sector. For example, this is because the internal components inside the gas flow need to be protected within each sector.

Since the provided flow pipe defined by the gas flow does not have an excessively large cross-sectional area, in most cases it can be treated as one annular gap centered on the central flow line of the flow pipe defined by the gas flow. At a predetermined distance from the annular gap, an umbrella jetting jet covering the entire end face of the flow pipe is generated. In most cases, it is advantageous when the annular gap is rotationally symmetrical on the axis of symmetry coinciding with the central flow line.

A preferred embodiment is a central injection chamber radially releasing into an annular gap surrounding itself, an inlet means for axial lead-in of compressed air flow into the injection chamber, and into a radial annular gap. Deflecting means for bypassing the axial compressed air flow.

For example, the deflection means for bypassing the axial compressed air flow into the radial annular gap can be designed in the form of a baffle. Such bulkheads are, of course, exposed to significant wear and tear. In order to reduce such wear damage, the inlet means for axial lead-in of compressed air flow into the central injection chamber can be provided with two inlet ports for compressed air flow facing in the axial direction. Because of this, compressed air flow is split into two powerful sub-flows that are approximately equal. This subflow flows axially towards each other from two opposing intakes, axially collides with each other in the injection chamber and thereby deflects into an annular gap.

By means of a throttleable auxiliary gas feeder into compressed air flow or two divided compressed air flows, the distribution of solid particles in the gas flow can be varied in a simple manner. The scattering of particles can be improved by a device for pulsed throttling of the auxiliary gas supply.

In a preferred embodiment, the device comprises a first deflector having a first outer edge and a second deflector having a second outer edge, wherein the first and second deflectors are sprayed by the first and second deflectors. The chambers are axially opposed to each other such that the chambers are formed and the first and second outer edges form an annular gap. The two deflectors are preferably mounted such that the two deflectors are axially adjustable to adjust the width of the annular gap. Both deflectors are preferably designed to be shell type. However, the two deflectors may also have a hemispherical shape, for example.

In a preferred embodiment, the apparatus comprises a distributor block for dividing the compressed air flow into two subflows. The first pipe is connected to the distributor block and forms a transfer line for the first subflow of compressed air flow. It extends across the gas flow and extends in parallel with the gas flow and is extended by a first pipe connecting tube carrying the first deflector. The second pipe is likewise connected to the distributor block and forms a transfer line for the second subflow of compressed air flow. It also extends across the gas flow and extends in parallel with the gas flow and is extended by a second pipe connector supporting the second deflector. The two pipes are advantageously arranged parallel to each other and are connected to each other by adjustable spacers. The adjustable spacer allows the axial gap between the two deflectors to be adjusted, thereby changing the width of the annular gap. Angle structures may be attached to the first and / or second pipes for wear protection.

The pipeline 10 shown in FIG. 1 is a large diameter cylindrical pipe. For example, this is the gas exhaust pipe of a steel mill electric furnace which can have a diameter of several meters. Primarily, laminar gas flows exist inside the pipeline, with gas velocity reaching up to 100 km. The flow direction of the gas flow is indicated by the arrow 12. Reference numeral 12 is also generally used to indicate gas flow. Reference numeral 11 denotes a central line of the pipeline 10 and at the same time a central flow line of the gas flow 12. The gas flow 12 surrounded by the pipeline 10 is also referred to as a “flow pipe”.

Reference numeral 14 designates the entire apparatus according to the present invention for injecting finely divided solid particles into the gas flow 12. The device shown is particularly concerned with finely ground lignite coke (grain size 1 mm or less). As already mentioned in the introduction, the quantity injected is relatively small (for example, from about 0.1 to 1 kg of lignite coke per 1000 Nm3 of exhaust gas), thus achieving an excellent distribution of powdered lignite coke over the entire cross section of the pipe. Should be.

The device 14 according to the invention is mounted radially inside the pipeline 10 via the side socket 16 of the pipeline 10. The finely divided solid particles (in this case pulverized lignite coke) are conveyed in the form of compressed air via the main connection line 18. The main connection line 18 is discharged into the solid distributor block 20 of a frictional resistance design which divides the compressed air flow into two subflows. In the distributor block 20, the first subflow is introduced into the first pipe 22 extending radially to the centerline 11 of the pipeline 10. The second subflow enters the second pipe 24 extending in parallel to the first pipe 22 to the centerline 11 of the pipeline 10 in the distributor block 20. The first pipe 22 has a first pipe connecting member 26 extending in a flow direction coaxial with the center line 11. The second pipe 24 has a second pipe connecting member 28 extending in a flow direction coaxial with the center line 11. The first pipe connecting member 26 supports the first clamshell-type deflector 30, and the second pipe connecting member 28 supports the second clamshell-type deflector 32. The two deflectors 30, 32 are positioned such that their respective outer edges 36, 38 form an annular gap 40, and axially face each other such that an injection chamber 34 is formed between the two deflectors. do. The annular gap 40 exhibits a rotationally symmetrical structure about an axis of symmetry coinciding with the centerline 11 of the cylindrical pipeline 10. The two pipe connecting pipes 26 and 28 form two inlets in the injection chamber 34 which face each other axially on the center line 11 and have essentially the same hole width.

Two compressed air subflows axially face each other from the two inlets 42 and 44 of the injection chamber 34 And thereby deflect in the direction of the mutual annular clearance 40. The radial deflection of the two subflows due to the axial collision naturally protects the two deflectors 30, 32. This is because both deflectors are much less exposed to abrasion damage.

On ejection from the annular gap 40, the solid particle velocity vector 46 is essentially perpendicular to the velocity vector 48 of the gas flow 12. By the sum of these vectors 46 and 48, an injection jet which is sprayed out in an umbrella shape and surrounded by the annular gap 40 is generated in the gas flow 12 direction. In fact, after ejection from the annular gap 40, the radial component of the velocity vector of the solid particles is gradually reduced by friction and pressure resistance in the direction across the gas flow 12, thereby gradually decreasing the solid particles. Accelerated in the axial direction by the gas flow (12). In Fig. 1, various flow paths of solid particles after being discharged from the annular gap 40 are indicated by the dotted lines 52. On discharge from the annular gap 40, this flow path 52 is essentially perpendicular to the flow direction 12, gradually bent in the flow direction 12, and finally parallel to the flow direction 12. do. For example, the difference in the flow path 52 is due to the fact that when ejecting from the annular gap 40, solid particles exhibit various ejection speeds, for example as a result of different accelerations or speed drops in the injection chamber 43. do. In most cases, solid particles also exhibit various shapes and sizes, which also affect the shape of the flow path due to friction or pressure resistance. In addition, it should be appreciated that turbulence may occur when flowing around the deflector 30, 32, which also affects various flow paths 52. Finally, such various flow paths 52 are of course desirable because they contribute to the enhanced scattering of solid particles in the laminar flow gas 12.

The distribution of solid particles in the laminar gas flow 12 can also be influenced by the width of the annular gap 4. This width can be adjusted in a very simple way by the adjustable spacer 60 between the first pipe 22 and the second pipe 24. By means of the adjustable spacer 60 it is possible to similarly adjust the annular gap 40 in case the two outer edges 36 and 38 are damaged. If the two pipes 22 and 24 cannot bend enough to allow the width adjustment of the annular gap 40 through the adjustable spacer 60, then the two pipe connecting members 26 and 28 may, for example, For example, it can be designed to be stretchable.

The distribution of solid particles in laminar gas flow 12 can be further enhanced by diluting the compressed air flow with the gas. To this end, for example, the distributor block has two throttleable auxiliary gas supplies 70 and 72 which allow the dilution gas to be transported freely through the first and second pipes. do. If there is a negative pressure in the pipeline 10, in most cases a compressed gas supplier will not need to be provided. In this case, the two throttle type auxiliary gas supplies 70 and 72 may be designed as a throttle type atmospheric pressure discharge line. Passing through the throttle-type auxiliary gas supplier 70, 72 can also be pulsed, so that in a very simple manner, there is a pulsed discharge rate that further improves the dispersion of solid particles in the laminar flow 12 Can be obtained in annular gaps. The device for pulsed throttling of the auxiliary gas supply may comprise, for example, an electromagnetically or pneumatically operated throttle valve with a relatively short opening and closing time. . The two throttle type auxiliary gas supplies 70 and 72 can be throttled synchronously or asynchronously. Asynchronous throttling can, in various cases, result as a result of further improved dispersion of solid particles in the laminar gas flow 12.

With regard to the first pipe 22 and the second pipe 24, they can be advantageously protected against abrasion in the flow direction by angle-iron. The change from the first pipe 22 or the second pipe 24 to the first pipe connecting member 26 or the second pipe connecting member 28 is protected by pipe bags 84 and 86. . Pipe bags 84 and 86 are filled with a solid material, so that friction between the solid material and the solid material occurs in this change zone.

Claims (16)

In the apparatus for injecting the finely divided solid particles into the gas flow 12, the finely divided solid particles are transferred to the device in the form of compressed air flow, Compressed air flow through itself has an annular gap 40 into which it flows into the gas flow 12, where the velocity vector 46 of the solid particles is essentially gas flow 12 when discharged from the annular gap 40. Is formed at right angles to the velocity vector 48 and summed with the velocity vector of the solid particles and the velocity vector of the gas flow to produce the jet jet 50 sprayed in an umbrella in the direction of the gas flow 12. Apparatus for injecting finely divided solid particles into the gas flow, characterized in that 40 is disposed inside the gas flow (12) The method of claim 1, The annular gap 40 is a device for injecting the finely powdered solid particles to the gas flow, characterized in that the rotationally symmetric structure. The method according to claim 1 or 2, The gas flow 12 represents a central flow line 11, and the annular gap 40 is formed of finely divided solid particles, characterized in that the center is located on the central flow line 11 of the gas flow 12. Apparatus for injecting gas flow. The method of claim 3, wherein The annular gap 40 is a device for injecting the finely powdered solid particles in the gas flow, characterized in that the rotationally symmetrical structure on the axis of symmetry coinciding with the central flow line (11) of the gas flow (12). The method according to any one of claims 1 to 4, A central injection chamber 34 radiating radially into the surrounding annular gap 40; Inlet means (26) (42) (28) (44) for introducing axial compressed air flow into the central injection chamber (34); And And deflecting means for bypassing the axial compressed air flow into the annular gap (40). The method according to any one of claims 1 to 5, Apparatus for injecting finely powdered solid particles into the gas flow, characterized in that it comprises a throttle type auxiliary gas supply (70) (72) to the compressed air flow. The method according to any one of claims 1 to 6, Apparatus for injecting finely divided solid particles into the gas flow, characterized in that it comprises a device for pulsed throttling of the auxiliary gas supply. The method of claim 5, The inlet means for the axial inlet of compressed air flow into the central injection chamber 34 comprises two axially facing inlets for compressed air flow; Here, the compressed air flow is divided into two sub-flows flowing toward each other from two opposing intakes (42) (44), axially colliding with each other in the injection chamber (34), whereby mutual annular gaps ( 40) A device for injecting finely divided solid particles into the gas flow, characterized in that radially deflected into. The method of claim 8, Apparatus for injecting finely divided solid particles into the gas flow, characterized in that it comprises a throttle type auxiliary gas supply (70) (72) into each of the two sub-flows. The method of claim 9, Apparatus for injecting finely divided solid particles into the gas flow, characterized in that it comprises a device for pulsed throttling of two auxiliary gas supplies (70) (72). The method according to any one of claims 1 to 10, A first deflector 30 having a first outer edge 36; And a second deflecting body 32 having a second outer edge 38. Here, in the first and second deflectors 30, the first and second deflectors form the injection chamber 34, and the first and second outer edges 36 and 38 define the annular gap 40. A device for injecting finely divided solid particles into a gas flow, characterized in that they are formed so as to face each other in an axial direction. The method of claim 11, The first and second deflectors 30 and 32 are mounted to allow the axial spacing to be adjusted so that the width of the annular gap 40 can be adjusted. Device. The method of claim 11 or 12, A distributor block 20 for dividing the compressed air flow into two subflows; A first pipe connection pipe connected to the distributor block 20 and forming a transfer line for the first sub-flow of compressed air flow, extending in parallel to the gas flow 12 and supporting the first deflector 30 ( A first pipe 22 extending across the gas flow 12, having a 26; A second pipe connecting tube connected to the distributor block 20 and forming a transfer line for the second sub-flow of the compressed air flow, extending in parallel to the gas flow 12 and supporting the second deflecting body 32 ( And (2) a second pipe (24) extending across the gas flow (12), wherein the finely divided solid particles are injected into the gas flow. The method of claim 13, The first and second pipes 22 and 24 are arranged in parallel with each other, and further comprising an adjustable spacer 60 connecting two parallel pipes 22 and 24 to each other. To inject the solid particles into the gas stream. The method according to claim 13 or 14, An apparatus for injecting finely divided solid particles into a gas flow, characterized in that it comprises a wear protection angle structure (80) (82) mounted to the first pipe (22) and / or the second pipe (24). The method according to any one of claims 1 to 15, Two deflectors (30) (32) is a device for injecting the finely powdered solid particles to the gas flow, characterized in that the shell-like structure.