JPS62123213A - Side angle two fluid atomizer - Google Patents

Abstract

PURPOSE:To spray pulverized CWM with a wide angle with respect to the center axis of an atomizer and improve ignitability by a method wherein an abrasion resistant collision plate is provided at the outlet port of the injection port of a two fluid atomizer and CWM, injected out of the injection port, is collided against the collision plate to pulverize the CWM of rough grain again. CONSTITUTION:The relative position between a peripheral rim section 16 and an injection port 4 is optimum in case the extension line of the injecting direction of the injection port 4 arrived at the surface of a conical surface and the peripheral rim section 16 of the collision plate 11 is located at the outside of the extension line of the injection port 4 in the injecting direction thereof. An intersecting angle theta should be at least 10 deg. or more and the length (l) in the direction of the matrix 14 of the annular peripheral rim section 16 of the cone of the collision plate 11 is enough to be 0.2-1.5 times of the diameter D of the injection port 4 while the annular peripheral rim section 16 should be slanted outwardly from the conical surface of the collision plate 11 or the angle of taper of the annular peripheral rim section 16 should be larger than the taper angle of the cone of the collision plate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a wide-angle two-fluid atomizer suitable for stabilizing the spraying and combustion of slurry fuel that is a mixture of coal and water.

[Background of the invention]

Since the oil crisis, the fuel for thermal power generation has changed from heavy oil to coal.
It is converting to LNG. More recently, to facilitate the transport and handling of solid fuels, slurries of coal mixed with water, oil, or methanol, or solid inferior residues such as pitch or oil coke mixed with water have been developed. Development of practical fuel technology is underway. The following is a representative example of slurry fuel CWM that is a mixture of coal and water.
(COAL WATERMIXTURE) will be described.

CWM is a fuel that is liquefied by mixing pulverized coal, water, and a small amount of surfactant, and can be atomized and combusted using an atomizer in the same way as liquid fuels such as heavy oil, but pulverized coal Compared to combustion, ignitability is poor and there is a large amount of unburned material. The reason for the poor ignitability is that heat is consumed in the evaporation of water, and the ignition distance in CWM combustion may be four times longer than the ignition distance in pulverized coal combustion. especially,
For I blue from the atomizer; bunch degree chi 4 bunch leech Ao IJ?
Sex is a sin (it turns out. Also, it is the spray CWM that has a large amount of unburned material.
This is because the pulverized coal particles are aggregated within the particles, so the individual pulverized coal particles are not burned completely as they are in pulverized coal combustion, and the combustion temperature is lowered by moisture.

Therefore, in order to improve the combustion efficiency of CWM' to almost the same level as the combustion efficiency of pulverized coal, it is of course necessary to produce highly concentrated CWM with less moisture, but it is also necessary to atomize the CWM atomized particles into smaller particles. It is necessary to prevent coal particles from agglomerating and to keep the jetting speed low.

Currently, almost all heavy oil-fired boilers use two-fluid atomizers that atomize the heavy oil by ejecting an atomizing medium such as air or steam. FIG. 10 shows a cross section of a Y-jet atomizer, which is the most common two-fluid atomizer. In FIG. 10, the Y-jet atomizer has an atomizer chip 3 attached to an atomizer body 18 and a cap nut 5.
This is how it is installed. In the atomizer main body 18, the fuel passages 2 are arranged in a circular pattern with the atomization medium passage 1 at the center. It is connected to aisle 2.

Y-jet atomizers are often used because the amount of ejection from each ejection hole 4 is approximately equal, and by increasing the number of ejection holes 4 (by increasing the total amount of ejection), the ejection speed is Because the flame is so fast, it may be difficult to maintain the flame stably, and the ejected particles have a relatively large diameter.

FIG. 11 shows the flow state of fuel and atomization medium in the ejection hole 4 of the Y-jet atomizer shown in FIG. 10,
4 schematically shows the state of fuel ejection at the outlet of the ejection hole 4. In FIG. 11, the inside of the fuel passage 2 is indicated by arrow 2'.
Fuel such as heavy oil flowing in the direction shown by collides with the inner surface of the jet hole 4 and forms an oil film 6 on the inner surface. Further, the atomizing medium such as air flowing in the direction shown by arrow 1' in the atomizing medium passage 1 flows in the direction shown by arrow 4' in the ejection hole 4. Therefore, the surface of the oil film 6 is blown away by the air flowing in the direction shown by the arrow 4', and becomes fine oil scum 7, which is ejected from the ejection hole 4 at a high speed. On the other hand, the oil film 6 near the inner surface of the nozzle 4 is torn off at the edge 17 of the outlet of the nozzle 4.
It erupts as 8 large oil droplets.

Even if heavy oil is in such a state of gushing, it will combust sufficiently in a heavy oil combustion boiler, but if the fuel is CWM,
Even if the ejected particles are fine, if the ejected speed is high, the ignitability will be poor, and if the ejected particles are large, the combustion state will be like dancing sparks (or fireflies), and the unburned amount will increase. Yes, this has been a problem for a long time.

[Purpose of the invention]

This invention was made to eliminate the above drawbacks.
When burning CWM using a two-fluid atomizer,
The object of the present invention is to provide a wide-angle two-fluid atomizer that has good ignitability and can eliminate the amount of ash and rice that is burned.

[Summary of the invention]

This invention provides a wear-resistant collision plate at the outlet of the nozzle of a two-fluid (Y-jet) atomizer, and makes the CWM ejected from the nozzle collide with this collision plate.
While re-atomizing coarse grain CWM of M, fine grain CWM
It is characterized by spraying WM at a wide angle with respect to the central axis of the atomizer.

[Embodiments of the invention] Embodiments of the invention will be described based on the drawings.

Figure 1 is a cross-sectional view of the wide-angle two-fluid atomizer of the present invention, and Figures 2 (a), (b), (C), and (dl are all enlarged views of section A in Figure 1, which has already been explained). The same numbers are used for the same parts as in FIGS. 10 and 11.

Figures 1 and 2 (a), (b), (cl.
, (d) +C, the conical collision plate 11 is attached to the atomizer chip 3 by the metal plate 12 and the set screw 3.
It is attached to. The conical surface of the collision plate 11 faces the ejection hole 4, and the axis of the cone of the collision plate 11 and the central axis of the atomizer chip 3 coincide. The collision plate 11 is made of ceramic and is designed not to wear out even if the CWM coal particles ejected from the nozzle holes 4 collide with it. Further, the conical peripheral edge 16 of the collision plate 11 is inclined outward from the conical surface, and the peripheral edge 16 has an annular shape.

Regarding such a collision plate 11, the diameter of the cone of the collision plate 11, that is, the relative position between the peripheral edge 16 of the collision plate 11 and the nozzle hole 4, and the axis of the cone of the collision plate 11 and the nozzle hole. 4, the intersection angle θ between the generating line 14 of the cone of the collision plate 11 and the central axis 15 of the nozzle 4 is determined, and furthermore, the annular shape of the cone of the collision plate 11' is determined. Various considerations were made regarding the length e in the direction of the generatrix 14 of the peripheral edge 16 of the collision plate 11, and how many times the conical peripheral edge 16 of the collision plate 11 should be inclined outward from the conical surface. I did it.

Figure 2 (a) shows the comparison test conducted for these studies.
, (b), (C), and (d). That is, the intersection angle θ is determined by ta+ and (C) and (b) and (d) in Figure 2, and (a) and fb) and (
C) and (d), the relative position between the peripheral edge 16 and the ejection hole 4, the particle size of the ejected CWM, and the atomizer chip 3
A comprehensive study was conducted by comparing the adhesion state of CWM to the surface of the metal plate 12, the rate of increase in ejection pressure, etc.

As a result, as for the relative position of the peripheral edge part 16 and the jet hole 4, as shown in FIG. The optimal case was that the peripheral edge 16 of the nozzle 11 was located outside the extension line of the nozzle 4 in the jetting direction. Also, the intersection angle θ is at least 10
° or more, and the conical peripheral edge 16 of the collision plate 11
The length l in the direction of the generating line 14 is 0.2 of the diameter of the nozzle hole 4.
It was found that it is sufficient if it is ~1.5 times. Further, if the annular peripheral edge 16 is inclined outward from the conical surface of the collision plate 11, that is, the taper angle of the circular peripheral edge 16 is larger than the conical taper angle of the collision plate 11. It turned out to be a good thing.

Since such a collision plate 11 is provided at the outlet of the jet hole 4, the coarse CWM of the CWM spouted from the jet hole 4 collides with the conical surface of the collision plate 11 and is crushed into a film.

The film-shaped CWM travels on the conical surface of the collision plate 11 and reaches the annular peripheral edge 16, and is torn off from the annular peripheral edge 16 by an atomizing medium such as air ejected from the jet hole 4. It is removed and becomes fine CWM. Note that the fine CWM particles ejected from the ejection holes 4 flow out along with the flow of the atomization medium such as air, and therefore do not coalesce on the conical surface of the collision plate 11.

Furthermore, as a result of examining the pressure-flow characteristics with the collision plate 11 attached, it was found that the rate of increase in the ejection pressure of the CWM and atomizing medium due to the attachment of the collision plate 11 was less than 10 inches; When the eruption of
It was confirmed that the collision plate 11 provided almost no resistance.

Further, since the annular peripheral edge 16 is inclined outward from the conical surface of the collision plate 11, the direction of CWM ejected from the ejection hole 4 is reversed, and the CWM wraps around the outer surface of the metal plate 12. adhesion is prevented. Therefore, the attached CWM becomes a carbon deposit due to the combustion heat in the combustion chamber, and the metal plate is heated by S, Na, etc. in the coal.
2 is prevented from being corroded.

FIG. 3 is a diagram showing the relationship between the gas-liquid ratio and the average atomized particle diameter of the wide-angle two-fluid atomizer of the present invention and the conventional Y-jet atomizer by curves 21 and 22, respectively. In addition, in FIG. 3 and FIGS. 4 to 8 described later, the fuel is CWM, and the atomization medium is air. Third
In the figure, as shown by curves 21 and 22, at the same gas-liquid ratio, the average spray droplet diameter when using the wide-angle two-fluid atomizer of the present invention is the same as the average spray droplet diameter when using the conventional Y-jet atomizer. It is approximately 1/2 of the diameter. In particular, the gas-liquid ratio, which is close to actual combustion conditions, is 0.15.
In this case, the average atomized particle size is significantly smaller. In this case, the average spray particle size is the average value of the maximum diameter of each spray particle in the same direction.

FIG. 4 is a diagram showing a pattern of a spray stream when combustion air is blown onto a CWM spray stream ejected from the wide-angle two-fluid atomizer of the present invention.

FIGS. 5A and 5B are diagrams showing the distribution of the amount of spray dispersion in the direction perpendicular to the central axis of the atomizer at positions A and B in FIG. 4, respectively.

4, 5(A) and 5(B), the CWM ejected from the wide-angle two-fluid atomizer of the present invention in which the collision plate 11 is attached to the atomizer chip 3 is approximately perpendicular to the central axis C of the atomizer chip 3. It spreads out in a flat disk shape in a wide angle direction. C spread out in the shape of a flat disk at this wide angle
When combustion air is blown onto the WM spray stream in the direction shown by arrow 9, the CWM spray stream spreads out into a flat disk shape.
The direction changes in the direction of the central axis C of the atomizer chip 3 and gathers, forming a bundle-shaped spray stream.

In this case, a backflow region 10 of the CWM spray is generated behind the collision plate 11, and the CWM spray spread in the shape of a flat disk slowly moves from the surroundings toward the central axis C of the atomizer chip 3. Alternatively, since the flame is returned to the direction of the atomizer chip 3, flame stabilization is extremely easy, and since there is a reductive combustion with insufficient O2, the generation of NOx is reduced. That is, the amount of dispersion of the spray CWM in the direction perpendicular to the central axis C of the atomizer chip 3 at the center CA of the backflow area 1o is dense in the outer peripheral part of the backflow area 10, as shown in FIG. 5(A). The shape of the spray CWM is a hollow cone. Further, the amount of dispersion of the spray CWM in the direction perpendicular to the central axis C of the atomizer chip 3 at the downstream position B of the backflow region 10 is as shown in FIG. 5(B).
It becomes dense near the central axis C of the atomizer chip 3,
The shape of the spray CWM is bundle-like.

FIG. 6 is a diagram showing the relationship between the gas-liquid ratio and the ignition distance of the wide-angle two-fluid atomizer of the present invention and the conventional Y-jet atomizer by curves 23 and 24, respectively.

As shown in Fig. 6, the ignition distance of the wide-angle two-fluid atomizer of the present invention is 1/2 to 1/3 short (1/2 to 1/3) of the ignition distance of the conventional Y-jet atomizer, and has good flame stability. .

FIG. 7 is a diagram showing the relationship between the gas-liquid ratio and the unburned fraction in the ash of the wide-angle two-fluid atomizer of the present invention and the conventional Y-jet atomizer by curves 25 and 26, respectively. As shown in FIG. 7, the unburned fraction in the ash when the wide-angle two-fluid atomizer of the present invention is used for combustion is 1. The unburnt content in the ash is significantly lower than that in the case of combustion using a conventional Y-jet atomizer, and the combustion is good.

FIG. 8 shows how the wide-angle two-fluid atomizer of this invention is used.
Combustion temperature and emission N when performing 0% two-stage combustion and when performing 30% two-stage combustion using a conventional Y-jet atomizer
FIG. 3 is a diagram showing the relationship with the Ox concentration using a fish school 27 and a fish school 28, respectively. Although the flammability when using the wide-angle two-fluid atomizer of this invention is better than the flammability when using the conventional Y-jet atomizer,
As already explained in FIG. 4, a reducing combustion zone lacking 02 is created behind the impingement plate 11, so that the exhaust NOx concentration is about 30 PFIl lower.

FIG. 9 is a diagram showing the relationship between the gas-liquid ratio and the generated soot concentration when the wide-angle two-fluid atomizer of the present invention and the conventional Y-jet atomizer are used in a boiler, using a Huo curve 29 and a curve 30. In this case, the fuel is kerosene and the atomization medium is steam. Steam atomization tends to increase the concentration of soot because the atomized fuel and combustion air do not mix well.However, when using the wide-angle two-fluid atomizer of this invention, the soot concentration increases. The soot concentration is reduced by more than 40% compared to the soot concentration generated when using a conventional Y-jet atomizer.Especially, the soot concentration generated at a gas-liquid ratio <0.15, which is close to the condition of a real can, is reduced by more than 40%. This indicates that the wide-angle two-fluid atomizer of the present invention can be put to practical use in boilers as an ignition torch that generates little black smoke.

As described above, the wide-angle two-fluid atomizer of the present invention has many advantages compared to the conventional Y-jet atomizer, but as shown in FIG. As a result, a spray interference portion 32 is formed. This is because the mixed jet flow of CWM and atomization air jetted from the jet holes 4 collides with the collision plate 11, and the spray flow 31 spreads in a fan shape, and the velocity of the spray flow 31 in the fan-shaped arc direction increases. This is due to the fact that it is slow. It has been confirmed through experimental observation that in the spray interference section 32, the spray particles tend to coalesce and the diameter of the spray particles increases.

Therefore, if the mixed jet flow of CWM and atomization air is jetted from the annular slit instead of from the jet hole 4, re-atomization is promoted without forming the spray interference part 32. However, it is difficult to align the center of the annular slit with the center of the atomizer, resulting in uneven combustion flame. In addition, in the annular slit, the cross-sectional area of the passage through which the mixed ejected flow of CWM and atomization air passes through becomes large, so the ejecting speed, that is, the speed at which it collides with the collision plate 11, becomes slow, and the ejected CWM is re-atomized. is not carried out effectively. Therefore, by changing the shape of the collision plate 11, the spray interference part 32 is not formed, and the spray C
It is designed to promote re-atomization of WM.

FIGS. 13A and 13B are diagrams showing examples of changes in the shape of the collision plate, and the same numbers are used for the same parts as those in FIG. 1 already explained.

In FIG. 13(A), a circular cup 33 is provided on the conical surface of the collision plate 11, which is an extension of the central axis 15 of the jet hole 4, and has a diameter of hl and a depth in the direction of the central axis 15. be. In addition, in FIG. 13(B), the collision plate 11 is placed on the conical surface of the collision plate 11 which is an extension of the central rib 15 of the jet hole 4.
A circular cup 34 is provided which has a depth h2 in a direction perpendicular to the conical surface and a diameter D2. Note that the circular cups 33 and 34 are made of ceramics, and the collision plate 1 is made of metal.
It is embedded in 1.

With this configuration, the coarse CWM of the ejected CWM ejected from the ejection hole 4 is re-atomized in the circular cups 33 and 34. The edges of the circular cups 33 and 34 promote re-atomization and narrow the fan-shaped spread of the spray flow 31 as shown in FIG. It has become.

In this case, the cross-sectional area of the jet stream jetted out from the jet hole 4 is wide at the conical surface of the collision plate 11, so the diameter D2 of the circular cup 33 and the diameter D2 of the circular cup 34 are larger.
It is desirable that the diameter of the jet hole 4 be approximately 1.2 times the diameter of the jet hole 4.

Further, the relationship between the depth dl and the diameter of the circular cup 33 and the relationship between the depth d2 and the diameter D2 of the circular cup 34 are o, i<cL/D+, dz/Dlz<0.5. desirable. The above d1/D1. When the value of d2/D2 is larger than 0.5, the re-atomization of coarse CWM among the ejected CWM ejected from the ejection hole 4 is promoted by the resonance effect, so-called resonance ultrasonic atomization effect.
Since the ejected CWM ejected from the ejection hole 4 collides with the circular cups 33 and 34 and jumps high, the sprayed CWM does not spread in a flat disk shape at a wide angle, as shown in FIG. 4, which has already been described.

Therefore, even if combustion air is blown onto the fuel, the spray CWM does not take the shape of a hollow cone, and the pattern of the spray flow of the spray CWM is disrupted.

FIGS. 14(a) and 14(b) are diagrams showing other embodiments of changes in the shape of the collision plate. Figure 14 (a) is a plan view,
FIG. 4(B) is a perspective view, and the same numbers are used for the same parts as those in FIG. 1 already explained.

In FIGS. 14A and 14B, the same number of fan-shaped concave surfaces 20 as the number of ejection holes 4 are provided on the conical surface of the collision plate 11 in correspondence with the ejection holes 4. The fan shape of the concave surface 20 corresponds to the fan shape of the spray flow 31 in FIG. is located in a plane containing

As a result, the ejection CWM ejected from the ejection hole 4 is caused by the concave surface 2
Since the spray spreads along a sector of 0, it does not interfere with adjacent spray streams. In this case as well, a ceramic collision plate 11 is attached to the atomizer chip 3 using a metal plate 12 and a set screw 13.

FIG. 15 is a diagram showing still another example of changing the shape of the collision plate, and the same numbers are used for the same parts as those in FIG. 1 already explained.

In FIG. 15, a plurality of steps having the same height are arranged concentrically around the axis of the cone of the collision plate 11.
It is arranged in a step-like manner on the conical surface. Then, the diameter D of the step S and the diameter D1+ of the step Sl+1 adjacent to the step S1,
And the relationship with the step is 0.5 < (Di++ Di) / 2 h <
2, and the relationship between the CWM maximum coal particle diameter Dfl], the diameter D and Di+1 of the adjacent step, the step, and the diameter of the nozzle hole 4 is Dm < (Di++ −Dl) (DDm<hiD If so, it has been found that re-atomization of the coarse CWM of the ejected CWM ejected from the ejection hole 4 is promoted.

If these conditions are violated, the spray flow pattern of the CWM spray will collapse, or the CWM coal particles will stick to the step-like steps, rendering the re-atomization effect ineffective. , a collision plate 11 made of ceramics is replaced with a metal plate 1
2 and a set screw (not shown) to attach the atomizer chip 3.
It is attached to.

FIG. 16 is a diagram showing a state in which an atomizer chip is provided with injection holes for injecting only an atomization medium such as air. 16th
In the figure (a), an atomizing medium injection hole 19 is provided between the injection holes 4. In addition, Fig. 16 (O
1, one atomizing medium injection hole 19 is provided on each side of each injection hole 4. Figure 16 (A) and (O)
In this case, since the diameter of the atomizing medium injection hole 9 is smaller than the diameter of the ejection hole 4, the pressure loss of the atomization medium is large and the flow rate is small (and the ejection speed is high. By injecting the atomizing medium from 19 and causing it to collide with the collision plate 11, the spray interference portion 32 shown in FIG. 12, which has already been explained, is prevented from being formed.
The atomizer chip 3 shown in Figure 6 (a) and (b),
When combined with the collision plate 11 having the step-like steps shown in FIG. 15, which has already been explained, the effect of re-atomization is remarkable, as will be explained below.

FIG. 17 shows the relationship between the gas-liquid ratio and the average atomized droplet diameter by curve 35 for the conventional Y-jet atomizer, by curve 36 for the wide-angle two-fluid atomizer of the present invention shown in FIG. ) and (b) according to the curve 37, and the atomizer of the present invention shown in FIG. 15 according to the curve 38, FIG.
The atomizer of the present invention shown in b) is represented by curve 39,
16A and 16B are diagrams showing a combination of the collision plate of the invention shown in FIG. 15 and the atomizer chip of the invention shown in FIGS. 16(a) and 16(b), respectively, by a curve 40. In addition, in FIG. 17 and later-described FIGS. 18 and 19,
The fuel is CWM and the atomization medium is air.

In FIG. 17, curve 35 and curve 36 overlap with curve 22 and curve 21 shown in FIG. 3, which have already been explained. As shown by curves 35 and 36, the average atomized droplet size when using the wide-angle two-fluid atomizer of the present invention shown in FIG. 1 is significantly larger than the average atomized droplet size when using the conventional Y-jet atomizer. However, when the gas-liquid ratio is >0.2, it becomes almost constant. This is because the spray particles coalesce together in the spray interference section 32 shown in FIG. 12, which has already been explained.

However, Fig. 13 (a) and (b), Fig. 15,
If the collision plate and atomizer chip shown in FIGS.
Re-atomization of WM is promoted, and the average atomized particle size decreases in the order of curves 37, 38, and 39. In particular, when the stepped collision plate 11 shown in FIG. 15 is combined with the atomizer chip 3 shown in FIGS. In other words, the gas-liquid ratio -〇. 1, about 1/4 of the average spray particle diameter when using a conventional Y-jet atomizer, and about 1/2 of the average spray particle diameter when using the wide-angle two-fluid atomizer of the present invention shown in FIG. .4, and the effect of re-atomization is remarkable.

FIG. 18 shows the relationship between the gas-liquid ratio and the ignition distance for a conventional Y-jet atomizer using a curve 41 as shown in FIG. 1 and as shown in FIG. 16A and 16B are diagrams showing an atomizer in which the stepped collision plate 11 of the present invention is combined with the atomizer chip 3 of the present invention shown in FIGS. 16(a) and 16(b), respectively, by a curve 43.

In FIG. 18, curves 41 and 42 overlap the curves 24 and 23 shown in FIG. 6, which have already been described. As shown by curves 41 and 42, the ignition distance of the wide-angle two-fluid atomizer of the present invention shown in FIG.
However, the ignition distance of an atomizer that combines the stepped collision plate 11 of the present invention shown in FIG. 15 and the atomizer chip 3 of the present invention shown in FIGS. 16 (A) and (-1) is As shown by curve 43, the ignition distance is even shorter than the ignition distance of the wide-angle two-fluid atomizer of the present invention shown in FIG. 1, which is effective in improving combustion near the burner.

FIG. 19 shows the relationship between the gas-liquid ratio and the unburned content in ash, with the conventional Y-jet atomizer shown in curve 44, the wide-angle two-fluid atomizer of the present invention shown in FIG. 1 shown in curve 45, and FIG. The stepped collision plate 11 and the first collision plate of the present invention shown in FIG.
An atomizer combined with the atomizer chip 3 of the present invention shown in FIGS. 6 (a) and (o) is shown by a curve 46
FIG.

In FIG. 19, curve 44 and song #! 45 overlaps with curve 26 and curve 25 shown in FIG. 7, which have already been explained. As shown by curve 44 and curve 45,
The unburned fraction in the ash when burned using the wide-angle two-fluid atomizer of the present invention shown in Figure 1 is significantly lower than the unburned fraction in the ash when burned using the conventional Y-jet atomizer. , the combustion is good, but the stepped collision plate 11 of the present invention shown in FIG. 15 and FIGS. 16(A) and 16(B)
As shown by curve 46, the unburned fraction in the ash when the atomizer is combined with the atomizer chip 3 of the present invention shown in FIG. It is even lower than the unburned fraction in the ash when burned, and the gas-liquid ratio is <0. Even under the condition of 1, the unburned fraction in the ash is less than 2 cm, which is sufficient for use as a raw material.

FIG. 20 shows the relationship between the gas-liquid ratio and the generated soot concentration by a straight line 47 for the conventional Y-jet atomizer, by a straight line 48 for the wide-angle two-fluid atomizer of the present invention shown in FIG. The stepped collision plate 11 of the invention and the first
The atomizer combined with the atomizer chip 3 of the present invention shown in FIGS. 6 (a) and (b) is connected by a straight line 49.
FIG. In this case, one fuel is light oil and the atomization medium is steam.

Steam atomization has tended to result in poor mixing of the atomized fuel and combustion air and to increase the concentration of soot produced. However, the soot concentration generated when using the wide-angle two-fluid atomizer of the present invention shown in FIG.
096 or more low. Further, when using an atomizer that combines the stepped collision plate 11 of the present invention shown in FIG. 15 and the atomizer chip 3 of the present invention shown in FIGS. 16 (a) and (b), the generated soot concentration is as follows: Compared to the soot concentration generated when using the wide-angle two-fluid atomizer of the present invention shown in FIG. 1, the soot concentration is further lower by 20 degrees or more. In particular, when the gas-liquid ratio (0.15) is close to the actual conditions, the soot concentration decreases markedly. From this, the stepped collision plate 11 of the present invention shown in FIG. It can be seen that an atomizer combined with the atomizer chip 3 of the present invention shown in (b) and (b) can be put to practical use in a boiler as an ignition torch that generates little black smoke.

〔Effect of the invention〕

According to this invention, the coarse CWM is re-atomized to reduce the particle size and is sprayed at a wide angle, which has the effect of improving ignition near the burner and reducing unburned content in the ash. There is. Also, there is a 0 behind the collision plate.
Since a reductive combustion region lacking 2 occurs, there is an effect of reducing the generation of NOx.

In addition, the ceramic collision plate has little wear and tear, and even if cracks occur due to thermal shock, etc., the metal plate holds them down, so the fragments do not fall off and the fuel spray pattern does not change suddenly.

Furthermore, since it generates less soot, when used as an ignition torch, it has the effect of reducing the amount of soot generated when starting a boiler.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the wide-angle two-fluid atomizer of the present invention, Fig. 2 (a), (b), (C), (dl are all enlarged views of section A in Fig. 1, Fig. 3 is the invention) FIG. 4 is a diagram showing the spray flow pattern of the wide-angle two-fluid atomizer of the present invention, and FIG. (A) and (B) are diagrams showing the distribution of the spray dispersion amount in the direction perpendicular to the central axis of the atomizer at the fourth @ position A and position iB, respectively, and Figure 6 shows the wide-angle two-fluid atomizer of the present invention and the conventional Figure 7 is a diagram showing the relationship between the gas-liquid ratio and the ignition distance of the Y-jet atomizer, Figure 7 is a diagram showing the relationship between the gas-liquid ratio and the unburned fraction in the ash, and Figure 8 is the same diagram showing the relationship between the combustion temperature and the exhaust NOx. Figure 9 is a diagram showing the relationship between the repelled gas-liquid ratio and the soot concentration, Figure 10 is a cross-sectional view of a conventional Y-jet atomizer, and Figure 11 is a diagram of a conventional Y-jet atomizer. Figure 12 is a diagram showing the spray interference part of the wide-angle two-fluid atomizer of the present invention, and Figures 13 (a) and (b) are the wide-angle two-fluid atomizer of the present invention. Figures 14 (a) and (b) showing examples of changes in the shape of the collision plate of the atomizer;
15 is a diagram showing another embodiment of the change in the shape of the collision plate of the wide-angle two-fluid atomizer of the present invention, FIG. 15 is a diagram showing still another embodiment of the change in the shape of the collision plate of the wide-angle two-fluid atomizer of the present invention, 16(A) and 16(B) are views showing the state in which the atomizer chip is provided with injection holes for only atomizing medium, FIG. 17 is a view showing the conventional Y-jet atomizer, and the wide-angle second one of the present invention shown in FIG. Fluid atomizer, the atomizer of this invention shown in FIGS. 13(a) and (b), the atomizer of this invention shown in FIG. 15, the atomizer of this invention shown in FIGS. 16(a) and (b), FIG. 16A and 16B are diagrams showing the relationship between the gas-liquid ratio and the average atomized particle diameter of an atomizer that combines the stepped collision plate of the present invention shown in FIG. 16 and the atomizer chip of the present invention shown in FIGS. Figure 18 is
A conventional Y-jet atomizer, a wide-angle two-fluid atomizer of the present invention shown in Fig. 1, a stepped collision plate of the invention shown in Fig. 15, and an atomizer chip of the invention shown in Figs. 16 (a) and (b). Figure 19 is a diagram showing the relationship between the gas-liquid ratio and the ignition distance of an atomizer that combines the two, Figure 19 is a diagram showing the relationship between the gas-liquid ratio and the unburned fraction in the ash, and Figure 20 is the same as the gas-liquid ratio and the ignition distance. FIG. 3 is a diagram showing the relationship with the concentration of generated soot. l... Atomization medium passage 2... Fuel passage 3...
Atomizer chip 4...Blowout hole 5...Cap nut 6...Oil film 7...Fine oil scum 8.
... Coarse oil scum 9 ... Arrow 10 ... Backflow area 11 ... Collision plate 12 ... Metal plate 13 ... Set screw 14 ... Bus bar 15 ...
- Central axis 16... Peripheral portion 17... Edge 18... Atomizer body 19... Atomization medium injection hole 20... Concave surfaces 21 to 26, 29
, 30 , 35-46...Curves 27, 28...Fish school 31...Fan-shaped spray flow 32...Spray interference part 33, 34...Circular cup 47-49...
・Straight line

Claims (1)

[Scope of Claims] (1) A plurality of ejection holes are arranged on the same circumference, and fuel is atomized by an atomizing medium inside each of the plurality of ejection holes, and the atomized fuel is transferred to each of the plurality of ejection holes. In the two-fluid atomizer that ejects water from each of the ejection holes, a conical collision plate has an axis that passes through the center of a circle having the same circumference in which the plurality of ejection holes are arranged and coincides with a direction perpendicular to the circle, A wide-angle two-fluid atomizer, characterized in that the conical surface thereof is provided so as to face the plurality of ejection holes. (2) In a plurality of planes including the axis of the cone of the collision plate and the central axes of the plurality of jet holes, the intersection angle between the generatrix of the cone of the collision plate and the central axis of the plurality of jet holes is 10°.
The wide-angle two-fluid atomizer according to claim 1, characterized in that: (3) The peripheral edge of the cone of the collision plate is inclined outward from its conical surface, and the length of the peripheral edge in the generatrix direction of the cone of the collision plate is 0.2 to 1 of the diameter of the jet hole. The wide-angle two-fluid atomizer according to claims 1 and 2, characterized in that the angle is .5 times larger. (4) The wide-angle two-fluid atomizer according to claims 1, 2, and 3, wherein the collision plate is made of ceramics. (5) Claims 1 and 2, characterized in that the bottom surface of the cone of the collision plate is covered with a metal plate.
The wide-angle two-fluid atomizer according to items 3 and 4. (6) The same number of fan-shaped concave surfaces as the plurality of ejection holes are provided on the conical surface of the collision plate, corresponding to the plurality of ejection holes, respectively, and the center axes of the plurality of fan-shaped concave surfaces are arranged so as to correspond to the plurality of ejection holes, respectively. Claims 1, 2, and 3 are located within a plurality of planes including the central axes of the plurality of jet holes and the axis of the cone of the collision plate. The wide-angle two-fluid atomizer according to items 4 and 5. (7) A plurality of steps having the same level difference are successively provided on the conical surface of the collision plate concentrically about the axis of the cone of the collision plate.
The wide-angle two-fluid atomizer described in Items 1, 2, 3, 4, and 5. (8) Equal step h of the plurality of steps and diameters D_i and D_i of adjacent concentric steps forming the step h
_+_1 is 0.5<(D_i_+_1-D_i)/2h<2, and the step h, the maximum particle diameter D_m of the fuel, the diameters D_i and D_i_+_1, and the diameter D of the plurality of ejection holes The wide-angle two-fluid atomizer according to claim 7, wherein the relationship between D_m<(D_i_+_1-D_i)<D D_m<h<D. (9) The collision plate is made of metal, and a ceramic cylinder having a bottom wall is placed on the bottom wall at a position of a conical surface of the metal collision plate extending from the central axis of each of the plurality of ejection holes. The wide-angle two-fluid atomizer according to claims 1, 2, and 3, wherein the wide-angle two-fluid atomizer is buried with its inner surface facing the ejection hole. (10) The inner diameter D' of the ceramic cylinder is longer than the diameter D of the jet hole, and the relationship between the depth d of the ceramic cylinder and the inner diameter D' is 0.1<d/
The wide-angle two-fluid atomizer according to claim 9, characterized in that D'<0.5. (11) The plurality of injection holes that inject only the atomized medium are arranged in the same direction as the ejection direction of the plurality of injection holes, and on the same circumference around which the plurality of injection holes are arranged. Claims 1, 2, 3, and 4
The wide-angle two-fluid atomizer described in Items 1, 5, 7, 8, 9, and 10. (12) The wide-angle two-fluid atomizer according to claim 11, wherein the diameter of the plurality of injection holes is smaller than the diameter of the plurality of injection holes.