JPH09287714A - Atomizer for slurry fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the atomization of a slurry fuel by a method wherein an atomization medium feeding annular passage is tapered in at the leading end side to accelerate an atomization medium, and the atomization medium is joined to a slurry fuel being fed from a slurry fuel feeding passage. SOLUTION: A fuel (CWM) 9 for which coal is atomized and mixed with water to be fluidized, is fed through a gun internal cylinder 8 which constitutes a double pipe, and an atomized medium (steam) 11 is fed from an annular passage between a gun external cylinder 10 which becomes the external shell of the double pipe, and the gun internal cylinder 8. The CWM 9 is slightly contracted in a CWM feeding nozzle 12, and flows into a primary mixing chamber 15 being formed of ceramic. The atomized medium (steam) 11 is accelerated through a conical annular type nozzle 14 which is annularly opened so as to be throttled by the conical shape, on the outside of the CWM feeding nozzle 12, and flows into the primary mixing chamber 15. At the primary mixing chamber 15, the CWM 9 and the atomized medium (steam) 11 are collided and joined, and a primary atomization is performed, and CWM 9 comparatively favorably splits, and jets into an internal mixing chamber 16.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CW for a boiler device.
The present invention relates to a structure of a slurry fuel atomizer that favorably atomizes (sprays) a slurry fuel such as M (high-concentration coal / water slurry).

[0002]

2. Description of the Related Art CWM is a fuel obtained by finely pulverizing coal and mixing it with water to make it fluid, and is mainly used in a boiler device as an alternative fuel from heavy oil to coal.

Although CWM is combusted after being atomized, atomization of the atomizer is a problem because it contains a large amount of water (30 to 40%) and has a high apparent viscosity. It is indispensable to generate a spray composed of fine droplets in an atomizer. In addition, nitrogen oxides (NOx) and carbon monoxide (CO) in exhaust gas
Also, good spraying is required to reduce unburned content in ash.

The problems involved in atomizing CWM are summarized as follows. (1) Atomization is poor. (2) In the two-fluid atomizer, many atomizing media such as steam and compressed air have to be consumed. (3) Wear is severe due to coal particles. If the ceramic piece comes off during operation, the combustion state may deteriorate. (4) Under a low load injection condition in which the CWM flow rate is small, the CWM is biased inside the atomizer due to the influence of gravity, and combustion becomes unstable. (5) Due to the atomizer having a complicated structure, even if the atomization is improved to some extent, a problem such as an increase in pressure loss, that is, a purging failure occurs.

In CWM combustion, even if the conventional atomizer for heavy oil is directly used, it is difficult to achieve the purpose. Many atomizer structures have been studied and proposed so far, but the internal mixing type two-fluid atomizer was the most comprehensively effective.

FIG. 15 [Sato et al. 4; The Japan Society of Mechanical Engineers, Volume 53, Volume 53, 494, (Sho 62-10), 29
95], FIG. 16 [see JP-A-6-170283], and FIG. 17 [see JP-A-4-90408],
1 shows the structure of an atomizer proposed for atomizing slurry fuel.

The atomizer shown in FIG. 15 has a primary mixing chamber 1
In 105, the fuel (CWM) 1103 and the atomization medium (vapor) 1104 collide at a right angle.
1101 is a mixing plate, 1102 is a noble plate,
Reference numeral 1106 is an internal mixing chamber, and 1107 is an ejection hole. In this case, the pressure loss is large and the injection pressure-flow rate relationship changes in a complicated manner.

In the atomizer shown in FIG. 16, the mixing chamber 12
06 is lengthened. 1201 is an atomizer, 1202 is a nozzle head, 1203 is a nozzle hole, 1204 is a fluid passage, and 1205 is an air passage.

The atomizer shown in FIG. 17 performs confluent mixing of the fuel and the atomizing medium (this part is called a first mixing chamber 1306).
It is performed in a plurality of Y-shaped parts such as a conventional Y-jet atomizer, and more than one first mixing chamber 1
306 is directed toward the center of the second mixing chamber 1308. 1
301 is a burner plug, 1302 is a fuel supply hole, 130
3 is a spray medium hole, 1305 is a fuel distribution chamber, 1307 is a burner tip, and 1309 is an injection hole.

[0010]

SUMMARY OF THE INVENTION As described above, the CW
In the combustion device for M, (1) Poor flame holding state due to unstable ignition (2) Increase of nitrogen oxide concentration in exhaust gas (3) To solve the problem of increase of unburned carbon in ash An atomizer with excellent atomization performance is essential.

On the other hand, in the atomizer for CWM, a portion that is deeply involved in atomization is subjected to a strong shearing force, so that it is heavily worn. Therefore, wear-resistant parts (pieces) made of ceramics are used, but if they are not mounted properly, the ceramic parts are damaged by thermal stress and the atomizer performance is deteriorated due to detachment. Therefore, it is necessary to devise a method for mounting ceramic parts in an atomizer having excellent durability and reliability.

An object of the present invention is to provide an atomizer for slurry fuel which can solve various problems in order to solve the above problems.

[0013]

In order to achieve the above object, the present invention provides a method in which a slurry fuel and an atomizing medium such as steam are combined in a primary atomizing section and then mixed in an internal mixing chamber to perform internal mixing. In a slurry fuel atomizer for spraying slurry fuel from an ejection hole communicating with a chamber, a slurry fuel supply passage for supplying the slurry fuel, and an atomization medium supply annular passage provided around the slurry fuel supply passage And merging means for accelerating the atomization medium by converging the atomization medium supply annular flow path on the tip side and merging with the slurry fuel supplied from the slurry fuel supply flow path. It is a thing.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION As will be described in detail later, the present invention improves (1) a confluence / mixing method of CWM and steam which is an atomizing medium, and primary (initial) atomization, and By optimizing the structure of the internal mixing chamber, primary atomization was promoted and the internal mixing chamber was not biased.

(2) A ceramic target is provided on the flow-opposing surface in the internal mixing chamber, and the method of fixing the ceramic pipe to the target and the ejection hole is improved.

CWM is supplied from the central axis of the atomizer, the atomizing medium is ejected from the annular flow path around the atomizer, and both fluids collide in the confluence chamber.

This merging point is the intersection of the atomizer central axis and the central axis of the annular flow path, and is inside the merging chamber. CW
There is a preferable range for the confluence angle between M and the atomizing medium, which are 25 ° or more and less than 75 °, and more preferably 4 or more.
It is in the range of 0 ° to 50 °. In this way, first CW
M and vapor as the atomizing medium mix well.

The size of the internal mixing chamber is preferably in the range of 1.5 or more and 4.0 or less with respect to the inner diameter (diameter) for atomization, but this size ratio is 2.5. By doing so, the best spray can be formed.

A target made of ceramics is used for the opposing wall in the internal mixing chamber, and the diameter of the target with respect to the confluence chamber is at least 1.1 times or more and less than 4 times.
This target is fixed to the atomizer, but is fixed to the inner wall of the internal mixing chamber by mechanical means at a plurality of points displaced from the central axis of the atomizer.

The ceramic pipe for preventing the wear of the ejection holes is
In the state of being inserted in the ejection hole, the upstream end is fixed by being pressed by the outer peripheral end of the ceramic target.

(3) In order to prevent the wear of the injection holes, there is a case where a ceramics tube coated with diamond having a thickness of 5 to 20 μm is used on the inner surface of the ceramics tube. In the present invention, in the intermediate plate portion, the CWM is supplied from the CWM supply nozzle on the central axis, and the steam, which is the atomization medium, collides with the CWM from the obliquely upward direction from the periphery thereof, so that the atomization is performed with the CWM. The media mix well in the primary mixing chamber.

Here, primary atomization of the CWM is performed.
The clumped CWM collides with a ceramic target on the opposing wall of the internal mixing chamber at high speed, resulting in a coarse CW.
The mass of M divides finely.

Since the size of the internal mixing chamber, that is, the ratio of the inner diameter to the axial length is appropriate, the mixture of CWM and vapor as the atomizing medium circulates and mixes well, and finally the furnace of the nozzle plate. Atomization is performed from the ejection hole that opens at the side tip. In this way, a good spray condition suitable for CWM combustion is produced.

Since the ceramic target is mechanically fixed to the opposing wall of the internal mixing chamber of the nozzle plate by a plurality of screws which are not coaxial with the center axis of the atomizer, it cannot be separated from the nozzle plate. Absent.

On the other hand, the ceramic pipe inserted in the ejection hole of the nozzle plate is also fixed by the ceramic target (this target plays a role of a stopper), and is not damaged or detached. Absent.

Further, when a ceramic tube coated with diamond on the inner surface is used, the hardness of diamond is the highest among the substances, so that the wear resistance can be dramatically improved. From the above, the atomizer according to the present invention ensures high atomization performance, high reliability, and durability.

FIG. 1 is a sectional view of a two-fluid atomizer according to the present invention. This atomizer is an internal mixing type, and in order from the downstream side to the upstream side, an internal mixing section in which the ejection holes 2 open to the furnace side, a primary mixing chamber 1 in which the CWM and the atomizing medium are mixed.
5 and an opening portion and a double-tube gun portion serving as a flow path for supplying the CWM and the atomization medium.

The CWM 9 is supplied through the gun inner cylinder 8 forming a double pipe. On the other hand, the atomization medium (steam) 11 is
It is supplied from the annular flow path between the gun outer cylinder 10 and the gun inner cylinder 8 which are the outer shells of the double pipe. The CWM 9 is slightly throttled by the CWM supply nozzle 12 and flows into the primary mixing chamber 15 formed of ceramics.

The atomizing medium (steam) 11 is accelerated through a conical ring-shaped nozzle 14 which is annularly opened so as to be conically narrowed outside the CWM supply nozzle 12, and the primary mixing chamber 1
5 flows into.

In the primary mixing chamber 15, the CWM 9 and the atomizing medium (vapor) 11 collide and merge with each other to perform primary atomization. Since the atomization medium (steam) 11 is accelerated, C
The WM 9 splits relatively well and spouts into the internal mixing chamber 16.

The internal mixing chamber 16 is constructed by locking the intermediate cover 7 and the nozzle plate 1 with screws. A plurality of ejection holes 2 are opened on the furnace side. A short tube-shaped ceramic pipe 3 is inserted into the ejection hole 2 for wear resistance.

A counterbore 4 is opened at the end of the ejection hole 2 on the furnace side so as to widen toward the end. This internal mixing chamber 16
In, the ceramic target 5 is provided on the opposite surface of the primary mixing chamber 15.

The ceramic target 5 is fixed to the nozzle plate 1 by two target stoppers 6. The ceramic pipe 3 is also fixed at the outer end of the ceramic target 5.
13 is an intermediate plate, 17 is a stopper, 1
Reference numeral 8 is a central axis, and 20 is a locking portion.

FIG. 2 shows a view of this atomizer as seen from the furnace side (a view from the direction AA in FIG. 1). Eight ejection holes 2 are opened in the nozzle plate 1 forming the internal mixing chamber. The ejection holes 2 are not even in the circumferential direction of the nozzle plate 1, and four ejection holes 2 are arranged close to each other to form two ejection holes 2
It is open to become a group of.

When the ejection holes 2 are opened in this manner, the ignition / flame holding properties are improved and the concentration of nitrogen oxides in the exhaust gas is also reduced as compared with the case where the eight ejection holes 2 are evenly opened in the circumferential direction. There is an advantage of doing.

FIG. 3 shows CWM 9 and atomization medium (steam) 1.
1 illustrates the geometrical relationship inside the primary mixing chamber 15 where the first merges. In this atomizer, CW
The central axis 18 of the M channel, that is, the central axis 18 of the atomizer
The central axis 14a of the conical annular nozzle 14 is connected to the intersection 15a inside the primary mixing chamber 15.

The angle between the central axis 18 and the central axis 14a of the conical annular nozzle 14, that is, the confluence angle θ _m, is 25 ° from the viewpoint of promoting atomization and preventing an increase in pressure loss.
It is preferably in the range of 75 ° or more and less than 75 °, more preferably 4
Set in the range of 0 ° to 50 °. In the embodiment shown in FIGS. 1 and 3, the merging angle is set to θ _m = 45 °.

FIG. 4 shows how the atomizing medium (vapor) 11 is accelerated in the conical ring type nozzle 14. The atomizing medium (steam) 11 is used in the primary mixing chamber 15
In the inside, it converges and accelerates so as to be focused, and collides and joins with CWM9 in a state where energy is concentrated,
Divide 9

FIG. 5 shows the structure of the internal mixing chamber 16. The ratio of the inner diameter D _m2 to the length L in the internal mixing chamber 16 is set to 1.5 ≦ D _m2 / L <4 (1).

If D _{m2 /} L <1.5, internal mixing chamber 1
Since 6 becomes flat, CWM 9 and atomization medium (steam) 1
Mixing of No. 1 is insufficient, and pressure loss tends to increase. On the other hand, if the internal mixing chamber 16 is elongated such that D _m2 / L> 4, the pressure loss is kept low, but the atomizer becomes large, and the CWM 9 is gravitationally moved to the internal mixing chamber 16 in the low load region. The problem arises that it is biased downward. From such a viewpoint, the size of the internal mixing chamber 16 is selected from the range of the above formula (1).

The outer diameter D _t of the ceramic target 5 provided at the facing portion of the inner mixing chamber 16 is 1.1 ≦ D _t / D _m1 <4.0 ... with respect to the inner diameter D _m1 of the primary mixing chamber 15.・ Set within the range of (2).

The role of the ceramic target 5 is to collide the CWM 9 split in the primary mixing chamber 15 to re-atomize it, and at the same time to create a uniform circulation / mixing flow in the internal mixing chamber 16. Therefore, the outer diameter D _t of the ceramic target 5 must be larger than the spread of the jet flow created in the primary mixing chamber 15.
The lower limit of the outer diameter D _{t in} the equation (2) is determined by such consideration. On the other hand, if Dt is too large, it is ineffective for forming the circulation / mixed flow in the internal mixing chamber 16. For the above reasons, the optimum dimensional ratio of the outer diameter D _t is given by the equation (2). In the embodiment shown in FIG. 1, D _t / D _m1 ≤
It was set to 2.6.

FIG. 6 shows a fixed state of the ceramic target 5. The ceramic target 5 is fixed by a target stopper 6 such as two screws so as to remove the central shaft 18. If the central axis 18
This is because if the target stopper 6 is fixed with one target stopper, the target stopper 6 is easily loosened due to the swirling action of the flow in the internal mixing chamber 16. Reference numeral 5a is a peripheral edge of the target.

7 and 8 show a fixing structure of the ceramic pipe 3 in the ejection hole 2. The ceramic pipe 3 is fixed at the outer peripheral end 5a of the ceramic target 5. Therefore, the eight ceramic pipes 3 are not directly fixed to the nozzle plate 1, which is the atomizer body. The assembling method is in the order of (1) to (3) below.

(1) First, eight ceramic pipes 3 are inserted into the eight ejection holes 2. (2) Place the ceramic target 5 so as to cover it from above, and press down all eight ceramic pipes 3. (3) The ceramic target 5 is fixed to the nozzle plate 1 by the two target stoppers 6. The above is the configuration of the internal mixing type two-fluid atomizer for slurry fuel embodying the present invention.

Next, the characteristics of the two-fluid atomizer embodying the present invention will be described based on the test results of atomization and combustion characteristics.

FIG. 9 summarizes data on the relationship of the spray average diameter to the gas-liquid flow rate ratio, and compares the characteristics of the atomizer according to the present invention and the conventional atomizer (FIG. 15).
The gas-liquid flow rate ratio Ws / Wc on the horizontal axis is a mass flow rate ratio obtained by dividing the flow rate Ws of the atomization medium (steam) by the CWM flow rate Wc, and is the standard gas-liquid flow rate ratio (Ws / Wc when a conventional atomizer is used. ) (*) Divided by and expressed as a relative value. The average spray diameter d _{32 on the} vertical axis is gas-liquid ratio = (Ws / Wc)
It is made dimensionless by dividing by the average spray diameter d ₃₂ (*) of the conventional atomizer obtained under the condition (*).

Generally, as the gas-liquid flow rate ratio increases, atomization becomes better and d ₃₂ decreases, but when compared with the same gas-liquid chamber flow rate ratio, d _{32 according to} the present invention is the same as that of the conventional atomizer. It is smaller than d ₃₂ . That is, it can be seen that the atomizer according to the present invention is superior in atomization characteristics under the same injection conditions. This is because, as described above, the atomization was improved by promoting CWM atomization in the primary mixing zone and optimizing the position of the target and the shape and size of the internal mixing chamber.

FIG. 10 is a comparison of the combustion characteristics of the atomizer according to the present invention and the conventional atomizer in relation to the NOx concentration in the exhaust gas and the unburned ash content.

The NOx concentration [NOx] on the horizontal axis is the average NOx concentration [NOx] when the conventional atomizer is used.
It is divided by (*) and expressed as a relative value. On the other hand, the unburned ash content U is the relative unburned ash content U / U (*) based on the average unburned ash content U (*) when using the conventional atomizer.
It is represented as

Although the data varies, the same NOx
Comparison based on the concentration shows that the unburned content in ash is lower when the atomizer according to the present invention is used.
Further, comparing the same unburned ash content, it was found that the NOx concentration was lower when the atomizer according to the present invention was used.

The above combustion characteristic improving effect is considered to be due to the following reasons. First, by improving atomization performance of the atomizer, ignition / flame holding conditions are improved and burnout is accelerated. Furthermore, a low O ₂ region in the flame center,
That is, since the reduction zone is formed, the NOx concentration also decreases.

FIG. 11 shows the structure of a two-fluid internal mixing type two-fluid atomizer according to another embodiment of the present invention. In this example, the diameter D of the collision part of the ceramic target 5 is
_t is set to be considerably smaller than that in the example of FIG.
The diameter D _m is about 1.4 times.

In the ceramic target 5,
The periphery of the collision portion is formed in a brim shape, and the ceramic pipe 3 in the ejection hole 2 is fixed at this portion. This fixing method is basically the same as the structure of the embodiment shown in FIG.

The structure according to the embodiment shown in FIG. 11 is suitable for the use of a fuel in which the apparent viscosity of CWM 9 at a low speed is high and the initial atomization state inside the atomizer is difficult to improve. That is, the collision atomization on the target 5 is promoted. By the way, the target 5 shown in FIG. 1 is not limited to collision atomization, but is also circulated and mixed in the internal mixing chamber 16 (mixing is mixing of the CWM 9 and atomizing medium).
It is suitable for atomizing CWM9, which has poor fluidity.

FIG. 12 shows another embodiment that embodies the concept of "supplying atomization medium from an annular flow path, converging the annular flow path, and colliding with CWM under the condition of maximum acceleration" which is the basis of the present invention. It is an example of the structure of.

This example is based on the conical ring type nozzle 1 shown in FIG.
4 is replaced with a cylindrical type. The atomizing medium (steam) 11 is passed through the cylindrical ring-shaped nozzle 19 and the primary mixing chamber 1
Guided to 5. The cylindrical ring-shaped nozzle 19 is the primary mixing chamber 1
Right before 5 and turn inward.

At this time, the flow path of the atomizing medium (vapor) 11 is narrowed (cross-sectional area reduction) and accelerated (broken line in the figure), and is accelerated to the maximum in the primary mixing chamber 15, the CWM supply nozzle 12 It is mixed and mixed with CWM9 introduced through. The degree of atomization in this region is the same as in the example of FIG. 1, but the pressure loss (particularly on the atomization medium side) is slightly large.

FIG. 13 shows the ceramic pipe 3 of FIG.
Instead of the above, an embodiment using a diamond-coated ceramic chip 30 in which a diamond layer 21 having a thickness of 5 to 20 μm is provided on the inner surface of a hollow cylindrical ceramic chip 23 is shown.

Silicon carbide (SiC) or silicon nitride (Si ₃ N ₄ ) was used as the ceramics, and the CVD method (chemical vapor deposition method) was used for the diamond coating. Diamond is the hardest of the materials and exhibits excellent wear resistance. However, diamond is originally an equiaxed crystal of carbon, and if oxygen is present, it oxidizes even at low temperatures, and when the temperature rises, the crystals deteriorate and wear resistance is lost.
It burns in the above air.

In this embodiment, the radiant heat is prevented from reaching the tip 23 by the locking portion 20 on the furnace side. Further, a chip 30 is provided on the internal mixing chamber side to prevent the radiant heat from the furnace side from reaching, and the chip 30 is cooled by stirring and mixing the CWM 9 and the atomizing medium in the internal mixing chamber 16 to reduce the temperature of the diamond layer 21. It prevents rising.

FIG. 14 shows a case where a diamond-coated ceramic chip 23 having a diamond layer 21 on the inner surface is provided as in FIG. 13. The difference from FIG. 13 is that it has a collar portion 22 on the inner mixing chamber side and a nozzle. The point is that the locking portion 24 of the plate 1 and the flange portion 22 are fixed.

When the flange portion 22 is used, the area on the side of the internal mixing chamber 16 is increased, and the cooling effect of the tip 30 by stirring and mixing the CWM 9 and the spray medium is increased. Although the locking portion 20 is not shown on the furnace side shown in FIG. 13 in FIG.
It is also possible to provide the corresponding locking portion 20 of the above.

[0064]

The effects produced by implementing the atomizer according to the present invention for the atomization of CWM are summarized as follows. (1) Atomization is promoted and a fine spray is obtained. (2) It is possible to reduce the amount of the atomizing medium, that is, the amount of steam or compressed air used, which makes it possible to maintain high operational economical efficiency in the boiler device. (3) Due to the effect of (1) above, the ignition / flame holding properties are improved and the flame becomes stable. (4) Due to the effect of (1) above, nitrogen oxides (NOx) in the flue gas are reduced.

(5) By the effect of the above (1), the unburned content remaining in the ash is reduced, and it becomes possible to treat the ash and effectively use the ash.

(6) CW made of coal which is relatively incombustible
It becomes possible to burn M well.

(7) The pieces (parts) constituting the atomizer have high wear resistance and long service life.

(8) The above piece (part) does not loosen or fall off during operation and is highly reliable.

(9) Since the flow paths for the CWM and the atomizing medium are constructed relatively smoothly, purging after the use is stopped is easy.

(10) It is easy to disassemble and assemble the atomizer.

(11) The pressure loss of the atomizer is small for the same reason as (9) above. This allows CWM
The power of the feed pump can be suppressed low.

(12) The wear resistance can be further improved by using a ceramic chip having a diamond layer on the inner surface.

(13) By providing the tip on the side of the internal mixing chamber, the tip can be cooled by stirring and mixing the CWM and the spray medium, and the radiant heat can be prevented from reaching and the alteration of the diamond can be prevented.

[Brief description of drawings]

FIG. 1 is a structural diagram of an atomizer according to a first embodiment of the present invention.

FIG. 2 is a view taken along the line AA of FIG.

FIG. 3 is a detailed cross-sectional view of a gas-liquid merging portion of the atomizer.

FIG. 4 is a BB direction view of FIG. 1.

FIG. 5 is a structural diagram showing a dimensional relationship of an internal mixing chamber.

FIG. 6 is a view as seen from the direction CC in FIG.

FIG. 7 is a view from the direction of D-D in FIG. 1.

FIG. 8 is a view showing a fixing structure of a ceramic piece inside an atomizer.

FIG. 9 is a characteristic diagram showing a relationship between a gas-liquid flow rate ratio and a spray average diameter.

FIG. 10 is a characteristic diagram showing the relationship between relative NOx and relative unburned ash content.

FIG. 11 is a structural diagram of an atomizer according to a second embodiment of the present invention.

FIG. 12 is a structural diagram of an atomizer according to a third embodiment of the present invention.

FIG. 13 is a structural diagram of an atomizer according to a fourth embodiment of the present invention.

FIG. 14 is a structural diagram of an atomizer according to a fifth embodiment of the present invention.

FIG. 15 is a structural diagram showing a first example of a conventional atomizer.

FIG. 16 is a structural diagram showing a second example of a conventional atomizer.

FIG. 17 is a structural diagram showing a third example of a conventional atomizer.

[Explanation of symbols]

 1 Nozzle Plate 2 Spout Hole 3 Ceramic Pipe 4 Counterbore 5 Ceramic Target 6 Target Stopper 7 Intermediate Cover 8 Gun Inner Cylinder 9 CWM 10 Gun Outer Cylinder 11 Atomization Medium 12 CWM Supply Nozzle 13 Intermediate Plate 14 Conical ring type nozzle 15 Primary mixing chamber 16 Internal mixing chamber 17 Stopper 18 Central shaft 20 Locking part

Front page continuation (72) Inventor Kokichi Kameda 6-9 Takaracho, Kure City, Hiroshima Prefecture Bab Kotsk Hitachi Ltd., Kure Factory (72) Hideo Okimoto 6-9 Takaracho, Kure City, Hiroshima Prefecture Bab Hitachi Industrial Co., Ltd. (72) Inventor Hisayuki Orita 7-1-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory

Claims (12)

[Claims] 1. A slurry fuel atomizer in which slurry fuel and atomizing medium are merged in a primary atomizing section and then mixed in an internal mixing chamber, and the slurry fuel is sprayed from ejection holes communicating with the internal mixing chamber, Slurry fuel supply flow path for supplying slurry fuel, atomization medium supply annular flow path provided around the slurry fuel supply flow path, and atomization medium supply annular flow path converged at the tip side to atomize A slurry fuel atomizer, comprising: a merging unit that accelerates the medium and merges with the slurry fuel supplied from the slurry fuel supply passage. 2. The structure according to claim 1, wherein an intersection of the axial direction of the flow path of the slurry fuel and the axial direction of the flow path of the atomizing medium is located in the internal mixing chamber. Slurry fuel atomizer. 3. The merging angle between the axial direction of the flow path of the slurry fuel and the axial direction of the flow path of the atomizing medium is 25 ° or more and less than 75 °. Slurry fuel atomizer. 4. The merging angle between the axial direction of the flow path of the slurry fuel and the axial direction of the flow path of the atomizing medium is 40 ° or more and less than 50 ° according to claim 1 or 2. Slurry fuel atomizer. 5. The atomizer for slurry fuel according to any one of claims 1 to 4, wherein the primary atomization section is provided with an internal mixing chamber having an ejection hole on the furnace side. 6. The ratio D _m2 / L between the inner diameter D _m2 of the internal mixing chamber and the length L of the internal mixing chamber according to claim 5,
An atomizer for a slurry fuel, which is 1.5 or more and less than 4.0. 7. A slurry fuel atomizer in which slurry fuel and atomizing medium are merged in a primary atomizing section and then mixed in an internal mixing chamber, and the slurry fuel is sprayed from ejection holes communicating with the internal mixing chamber, An atomizer for a slurry fuel, characterized in that a hard target is provided on the side of the internal mixing chamber facing the primary atomization section. 8. The atomizer for slurry fuel according to claim 7, wherein the target is fixed to a nozzle plate forming an internal mixing chamber at a position not coaxial with the atomizer central axis. 9. The atomizer for slurry fuel according to claim 7, wherein a wear resistant pipe to be inserted into the ejection hole is fixed by using the target. 10. The atomizer for slurry fuel according to claim 8 or 9, wherein the target or pipe is fixed to the nozzle plate by combining mechanical means and an adhesive. 11. The atomizer for slurry fuel according to claim 7, wherein the diameter of the target is 1.1 times or more and less than 4.0 times the diameter of the merging / mixing chamber. 12. The atomizer for slurry fuel according to claim 7, wherein a ceramic chip having an inner surface provided with a diamond layer is provided in the ejection hole.