JP3382320B2 - Two-fluid nozzle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-fluid nozzle,
More specifically, the present invention relates to a two-fluid nozzle capable of spraying fine particles, for cooling by spraying a gas-water mixed mist on a high-temperature gas generated from an incinerator, for example. 2. Description of the Related Art Conventionally, a two-fluid nozzle R of this type has a liquid inlet 1 and a gas inlet 2 as shown in FIG.
The nozzle body 3, the liquid nozzle 4, the gas nozzle 5, the retainer ring 6 attached to the nozzle body 3 in a state where the liquid nozzle 4 and the gas nozzle 5 are assembled, and the nozzle body 3 and the liquid And an O-ring 7 made of rubber that is interposed between the O-ring 7 and the nozzle 4. In the above-mentioned nozzle R, liquid is supplied from the nozzle body 3 to the axial center of the nozzle R through the liquid nozzle 4, while gas passes through the flow path 8 on the outer periphery of the liquid nozzle 4,
The gas is introduced into the gas nozzle 5 through the orifice 9 formed in the liquid nozzle 4, and the gas is mixed with the outer periphery of the liquid in the gas-liquid mixing chamber 10 of the gas nozzle 5. An air-water mixture mist is sprayed from a discharge port 12 slit to 11. [0004] In the nozzle R, a liquid is supplied to the shaft center portion and a gas is mixed with the outer periphery of the liquid. Therefore, the particle size of the sprayed water-water mixture mist is as shown in FIG.
As shown in the figure, the central part is large, the outer peripheral part is small,
There are disadvantages that the particle diameters are not uniform, and there are many other problems such as clogging easily at the orifice 9 and foreign matter easily accumulating at the corner 5a of the gas nozzle 5. Accordingly, the present applicant has previously disclosed in Japanese Patent Laid-Open No.
No. 3565 has provided a two-fluid nozzle capable of achieving uniform spraying over a wide range, in particular, in which the particle size, liquid amount and air amount can be made uniform over a wide range. The two-fluid nozzle S
As shown in FIG. 21, at the base end side of the nozzle body 20, the liquid inlet 2 is formed on the outer periphery of the gas supplied from the gas inlet 25 through the orifice 30 along the first axis O.
6 and a first mixing chamber A for supplying and mixing the liquid through the liquid inflow passage 31 and communicating with the first mixing chamber A to flow the mixed fluid to the tip side along the first axis O. A second rectifying chamber B having a large diameter is provided at the distal end side of the rectifying chamber B.
A mixing chamber C is provided, and a rectifying chamber B is provided at the end of the second mixing chamber C.
The outer peripheral surface of the mixed fluid ejected into the second mixing chamber C forms a wall surface 40 against which the fluid collides, and is sprayed from the discharge port 42 through the ejection chamber E communicating with the front end side of the second mixing chamber C. I have. The nozzle S adopts a method in which gas is supplied along the first axis O and liquid is supplied to the outer periphery thereof. The gas-liquid mixed fluid mixed in the first mixing chamber A is
After flowing through the rectification chamber B, it is diffused in the second mixing chamber C, and the outer peripheral portion of the gas-liquid mixed fluid is forced to collide with the wall surface 40. Due to the collision with the wall surface 40, as shown in FIG. 22, water droplets having a large particle diameter in the outer peripheral portion are reduced in diameter, and the particle diameter can be made uniform. Accordingly, in combination with the special shape of the discharge port 42, it is possible to obtain a spray having a substantially uniform particle size, air amount, and liquid amount over a wide range. However, as described above, in a two-fluid nozzle for cooling by spraying a gas-water mixture mist on a high-temperature gas generated from an incinerator, for example, a gas-water mixture mist is used. By spraying fine particles, the running cost of maintenance such as reduction of air consumption, wetting of incineration ash, wetting and replacement of dust collectors can be reduced, and finer particles can be sprayed. By using fine particles, there is a demand that the evaporation time is shortened, and as a result, the height of the cooling tower can be designed to be low, and the initial cost should be reduced. SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demand, and has as its object to provide a two-fluid nozzle capable of spraying fine particles by making the particle size of the air-water mixed mist finer. Things. In order to achieve the above object, the present invention provides a method for supplying a liquid to an outer periphery of a gas supplied along an axis at a base end side of a nozzle body. In a two-fluid nozzle that mixes within and sprays a gas-water mixed mist from a discharge port, a passage until the mixed fluid mixed in the nozzle body is sprayed from a discharge port, the outer peripheral portion of the mixed fluid An object of the present invention is to provide a two-fluid nozzle characterized in that wall surfaces against which fluid collides are formed in multiple stages.
The discharge port may have a circular single hole at the center of the axis. Alternatively, a plurality of circular holes may be formed around the center of the axis at a fixed angular interval.
Alternatively, a hole may be provided at the center, and a plurality of holes may be formed at intervals on the outer periphery. More specifically, the present invention provides a first mixing chamber for supplying and mixing a liquid to the outer periphery of a gas supplied along an axis at a base end side of a nozzle body, A rectifying chamber which communicates with the chamber and circulates the mixed fluid to the distal end along the axial line, a second mixing chamber having a large diameter is provided at the distal end of the rectifying chamber, and a distal end of the second mixing chamber is provided; A small-diameter injection chamber is provided on the side, and a wall between the outer peripheral portion of the mixed fluid and the fluid that collides with the passage between the front end side of the second mixing chamber and the front end side of the injection chamber is formed in multiple stages Through the injection chamber, a circular single hole opened at the center of the axis, a plurality of circular holes spaced at a fixed angular interval around the center of the axis, or the single hole A two-fluid nozzle characterized by being sprayed from a discharge port consisting of a combination of It is intended to. In the case of the above-mentioned porous structure, a circular hole is basically formed in the tip end surface of a nozzle body having a multi-stage collision wall surface, but a nozzle tip having a multi-stage wall surface is formed. To each of the many holes formed in the nozzle head,
Walls with which the liquid at the outer peripheral portion of the mixed fluid collides may be provided in multiple stages for each hole. According to the present invention, before the mixed fluid mixed in the nozzle body is sprayed from the discharge port, the passage is formed with multi-walled walls against which the fluid at the outer peripheral portion of the mixed fluid collides. By doing so, a water droplet having a large particle diameter in the outer peripheral portion collides with the multi-stage wall surface many times to make the diameter smaller, so that the particle diameter can be made finer and uniform. Moreover, in the past, the discharge port was cut into the outer peripheral portion, so that there was a risk that non-miniaturized mist would be discharged. However, in the present invention, since the discharge port is circular, fine mist generated in the center portion Only can be sprayed. Further, when the discharge port is made porous, the spray range uniformly distributed can be widened. In the case of making the discharge port porous, conventionally, a nozzle tip is provided in each hole, and each nozzle tip and the ejection chamber are communicated with a dedicated passage. Are simple holes, and each hole is directly connected to the injection chamber, so that the number of parts is small, the structure is simple, and the spray (spray) balance is good. Thus, with the two-fluid nozzle of the present invention, it is possible to obtain a substantially uniform spray with a finer particle size, a smaller amount of air and a smaller flow rate over a wide range. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. 1 to 3, reference numeral 20 denotes a nozzle body;
Is a core, 22 is a chip, and 23 is a cap.
Assembled from two parts. The nozzle body 20 includes:
A large-diameter gas inlet 2 having a substantially cylindrical shape and connected to a gas supply pipe and a liquid supply pipe (not shown) at both left and right ends thereof.
5 and a liquid inlet 26, and at the center in the axial direction, a concave portion 27 having an open upper surface in the figure is provided, and a female screw portion 27a for screwing the cap 23 into the inner peripheral surface of the concave portion 27 is formed.
Is formed. Gas inlet 25 connected to the gas supply pipe
At a position below the second axis P of the nozzle body 20,
In addition, a small-diameter gas inflow passage 28 formed in parallel with the second axis P is communicated. The gas inflow passage 28 is bent toward the recess 27 at the center of the nozzle
An orifice 30 is formed by opening a central portion of the bottom surface of the partition 7 and projecting a partition wall portion 29 into the concave portion 27 along the outer periphery of the opening. The liquid inlet 26 connected to the liquid supply pipe has a small-diameter liquid opening on a part of the outer peripheral surface of the recess 27 along the second axis P, that is, above the gas inflow passage 28. An inflow passage 31 is provided. The core 21 is fitted into the recess 27, the tip 22 is fitted to the tip of the core 21, and the cap 23 is fitted to the core 21 and the tip 22. The nozzle is assembled by screwing the nozzle 20. The core 21 fitted in the concave portion 27 of the nozzle body 20 has a tapered hole 3 expanding downward and conically below the small diameter hole 32 formed along the first axis O from the upper end.
3, and the tapered hole 33 is formed in the partition wall portion 29.
It is arranged so as to leave a gap. In the gap, the space between the outer wall at the upper end of the partition wall portion 29 and the inner wall of the tapered hole 33 is reduced, and the narrow gap acts as the orifice 43. With this configuration, the orifice 30
More gas is ejected to the center of the tapered hole 33,
The liquid is ejected from the orifice 43 to the outer peripheral portion of the gas, so that the liquid is supplied to and mixed with the outer peripheral portion of the gas in the first mixing chamber A formed inside the tapered hole 33. The small-diameter hole 32 communicating with the tapered hole 33 is set relatively long to form a long rectifying chamber B so that the rectifying action of the mixed fluid mixed in the first mixing chamber A is sufficiently performed. ing. The tip 2 connected to the tip of the core 21
2, on the base end side communicating with the rectification chamber B,
The second mixing chamber C is provided by forming a large-diameter hole 36 larger than the diameter of the rectification chamber B. A medium diameter hole 39 is formed at the tip end of the tip 22, the medium diameter hole 39 communicates with the tip end of the large diameter hole 36, and an injection chamber E is provided.
A flat first wall surface (step portion) 40 a is formed on the outer peripheral portion of the middle diameter hole 39 in a communicating portion between the inner diameter hole 6 and the middle diameter hole 39.
In addition, the first axis O
Is formed at the center of the hole, and a discharge port 4a is formed at the communicating portion between the medium diameter hole 39 and the discharge port 42a.
A flat second wall surface (step portion) 40b is formed on the outer peripheral portion of 2a. As described above, the first wall surface 40a is formed on the outer peripheral portion of the distal end surface of the second mixing chamber C, and the second wall surface 40b is formed on the outer peripheral portion of the distal end surface of the injection chamber E. The outer peripheral fluid of the mixed fluid injected from B into the second mixing chamber C collides with the first wall surface 40a and the outer peripheral fluid of the mixed fluid injected from the second mixing chamber C into the injection chamber E Is caused to collide with the second wall surface 40b. Therefore, the diameter of the rectification chamber B is D1, the diameter of the second mixing chamber C is D2, the diameter of the injection chamber E is D3, and the discharge port 4 is
Assuming that the diameter of 2a is D4, D1 ≦ D2 ≧ D3 ≧ D4. Further, the length L1 of the second mixing chamber C and the length L2 of the injection chamber E are set such that the fluid at the outer peripheral portion of the mixed fluid injected from the rectification chamber B into the second mixing chamber C is forced to collide with the first wall surface 40a. At the same time, the length is set such that the fluid at the outer peripheral portion of the mixed fluid injected from the second mixing chamber C into the injection chamber E is forced to collide with the second wall surface 40b. Next, the operation of the two-fluid nozzle having the above structure will be described. The gas (air in the present embodiment) flowing from the gas inlet 25 of the nozzle body 20 is jetted from the orifice 30 into the first mixing chamber A at the center axis of the nozzle, and the liquid is applied to the outer periphery of the air. The liquid (water in this embodiment) flowing from the inflow port 26 is ejected from the orifice 43, and the water is mixed from the outer peripheral portion of the air. By the mixing in the first mixing chamber A, the air and the water are almost completely mixed, but the outer peripheral portion has a large water droplet and the central portion has a small water droplet. Flows into the rectification chamber B. Therefore, in the rectification chamber B, the air-water mixture having large water drops flows along the inner wall, and the air-water mixture having small water drops flows at the center. The gas-water mixture ejected into the second mixing chamber C having a larger diameter than the end of the rectification chamber B diffuses as shown in FIG.
The liquid mixture mainly in the outer peripheral portion collides with the first wall surface 40a on the front surface. Therefore, a water droplet having a large particle size at the outer peripheral portion becomes a water droplet having a small particle size, and has a particle size substantially equal to the water droplet at the central portion. When the gas-water mixture having a substantially uniform particle diameter flows into the injection chamber E having a small diameter, the mixture at the outer peripheral portion mainly collides with the second wall surface 40b on the front surface. Therefore, the water droplet having a large particle diameter at the outer peripheral portion becomes a water droplet having a smaller particle diameter, has a fine particle diameter substantially equal to the water droplet at the central portion, and is ejected from the discharge port 42a. The jetted water-water mixture mist has a wide-angle circular spray pattern as shown in FIG. 10, and the fine particle diameter is uniform over the entire spray pattern, as shown in FIG. It becomes almost equal. In the air / water mixing nozzle of the type in which air is supplied to the center of the nozzle and water is supplied to and mixed with the outer periphery of the nozzle as in the present invention, the particle diameter of water droplets at the outer periphery of the mixture is reduced. It is inevitable that it grows. Therefore, the large water droplets on the outer peripheral portion are forcibly applied to the wall surface 40 as in the present invention.
In the case where a means for reducing the diameter by colliding with the nozzles a and 40b is not used, as shown in FIG. 20B, the particle diameter at the periphery of the spray pattern becomes large. In contrast, FIG.
(A) As shown in FIG. 20 (B), if the diameter is reduced by colliding with the one-stage wall surface 40 as in the conventional nozzle (corresponding to the nozzle in FIG. 20), the particle indicated by the dashed line in FIG. Those having a particle diameter larger than the diameter are eliminated, and the particle diameter can be equalized. In the present invention, the wall for collision is shown in FIG.
5 (A) and 5 (B), instead of a single stage like the conventional nozzle shown in FIGS. 5 (A) and 5 (B).
Since they are a and 40b, the fineness and uniformity of the particle size are further promoted. FIGS. 6A and 6B
As shown in (3), if the wall surfaces 40a, 40b, and 40c are formed in three stages, the fineness and uniformity of the particle size are further promoted. FIG. 15 is a data graph showing the relationship between the number of steps on the wall surface and the particle diameter, where b is the particle diameter by the nozzle of the one-step wall 40 in FIG. 4, and a is the two-step wall in FIG. 40a,
40b is the particle size due to the nozzle. As is clear from the figure, at the air-water ratio of 100, b has a maximum particle size of 400 μm, whereas a has a maximum particle size of 290 μm, and a
It can be seen that is finer. The discharge port 42a of the nozzle of the above embodiment is a single hole formed at the center of the first axis O, but FIG.
As shown in (B), a plurality of discharge ports 42b formed of a plurality of holes spaced at a fixed angular interval around the center of the first axis O and at a position close to the first axis O. It may be. As shown in FIGS. 8A and 8B, the single-hole discharge port 42a and the multi-hole discharge port 42b may be combined. For reference, FIGS. 9 (A) and 9 (B) show a fixed angular interval at a position which is concentric with the center of the first axis O but far from the first axis O. A plurality of perforated discharge ports 42b 'are illustrated. Although the number of the porous discharge ports 42b in FIGS. 7 and 8 is eight, FIG.
As shown in (E) to (E), an appropriate selection may be made in a range of about 2 to 12 pieces. If the shape of the porous discharge port 42b is as shown in FIG. 7, as shown in FIG.
Compared to the shape of 2a, although the center part is blank, the spray pattern becomes wider, and the particle size around the spray pattern is slightly larger, but the particle size is uniform,
In addition, the air amount and the liquid amount are substantially equal. Accordingly, the single-hole discharge port 42a shown in FIG.
The shape of the discharge ports 42a and 42b in FIG. 8 in which the porous discharge ports 42b in FIG. 11 are combined with each other as shown in FIG.
FIG. 10 and FIG. 11 are combined to form a spray pattern having a wider angle and a substantially circular shape with no blank at the center. In addition,
If the shape of the porous discharge port 42b 'is as shown in FIG. 9, as shown in FIG. 13, the spray pattern becomes wider than the spray pattern shown in FIG. Absent. FIG. 16 is a data graph showing the relationship between the position of a single hole or a hole and the particle diameter, where a is the particle diameter of the nozzle of the single hole discharge port 42a in FIG. In the porous discharge port 42b, the diameter is a particle diameter of the nozzle located near the first axis O, and d is the porous discharge port 42 in FIG.
b ′ is the particle diameter of the nozzle located far from the first axis O. As is clear from FIG.
a has a maximum particle size of 290μ, whereas c has a maximum particle size of 350μ and d has a maximum particle size of 500μ, and a is smaller than c and c than d. You can see that. FIG. 17 is a data graph showing the relationship between the discharge port and the particle diameter according to the present invention and the conventional one, where a is the particle diameter by the nozzle of the single-hole discharge port 42a in FIG.
1 is the particle diameter due to the nozzle of the porous discharge port 42b, e
Is the particle diameter of the conventional single-hole discharge port nozzle without the collision wall surfaces 40a to 40c, and f is the collision wall surfaces 40a to 4c.
It is the particle diameter by the nozzle of the conventional porous discharge port without 0c. As is clear from the figure, at the air / water ratio of 100, a has a maximum particle size of 290 μm, b has a maximum particle size of 350 μm, e has a maximum particle size of 500 μm, and f has a maximum particle size of 500 μm. It can be seen that the diameter is 580 μm, and e is smaller than f, c is smaller than e, and a is smaller than c. FIG. 18 shows an application example, in which a head 45 is attached to the nozzle body 20, and a plurality of nozzle tips 46 formed by unitizing the core 21 and the chip 22 are attached to the head 45 to form a porous discharge port. It was done. As is clear from the above description, in the two-fluid nozzle of the present invention, the fluid at the outer peripheral portion of the mixed fluid collides with the passage before the mixed fluid is sprayed from the discharge port. Since the wall surfaces are formed in multiple stages, water droplets having a large particle diameter in the outer peripheral portion collide with the multiple stage wall surfaces many times, so that the diameter can be made smaller and the particle size can be made finer and uniform. Therefore, for example, the particle size of the air-water mixture mist becomes finer to the high-temperature gas generated from the incinerator, and by spraying these fine particles, the amount of air used is reduced, the incineration ash is wet, and the dust collector is wet. Since the running cost such as maintenance for replacement or replacement is reduced and the evaporation time is shortened, the height of the cooling tower can be reduced as a result, and the initial cost is reduced. Further, by making the discharge port porous, the spray range uniformly distributed can be expanded, and a substantially uniform spray can be obtained with a finer particle size, a smaller amount of air and a smaller flow rate over a wide range. Will be able to do it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a two-fluid nozzle of the present invention. FIG. 2 is a front view of the nozzle of FIG. FIG. 3 is an exploded perspective view of the nozzle of FIG. FIG. 4A is a front view of a conventional nozzle having a single-hole discharge port and a one-step wall surface, and FIG. 4B is a side sectional view of FIG. FIG. 5A is a front view of a nozzle of the present invention having a single-hole discharge port and two-step wall surfaces, and FIG. 5B is a side sectional view of FIG. FIG. 6A is a front view of a nozzle of the present invention having a single-hole discharge port and three-step wall surfaces, and FIG. 6B is a side sectional view of FIG. 7A is a front view of a nozzle of the present invention having a porous discharge port and two-step wall surfaces, and FIG. 7B is a side sectional view of FIG. 8A is a front view of a nozzle of the present invention having a single hole, a porous discharge port, and two-step wall surfaces, and FIG. 8B is a side sectional view of FIG. 9A is a front view of a reference nozzle having a porous discharge port and a one-step wall surface, and FIG. 9B is a side sectional view of FIG. 9A. FIG. 10 is an explanatory diagram of a spray pattern of a nozzle of the present invention having a single-hole discharge port and two-step wall surfaces. FIG. 11 is an explanatory view of a spray pattern of a nozzle of the present invention having a porous discharge port and two-step wall surfaces. FIG. 12 is an explanatory view of a spray pattern of a nozzle of the present invention having a single hole, a porous discharge port, and two-step wall surfaces. FIG. 13 is an explanatory diagram of a spray pattern of a reference nozzle having a porous discharge port and a one-step wall surface. 14A to 14E are front views of nozzles each having a different number of holes. FIG. 15 is a data graph showing the relationship between the number of steps on the wall surface and the particle size. FIG. 16 is a data graph showing the relationship between the position of a single hole or a hole and the particle size. FIG. 17 is a data graph showing a relationship between a discharge port and a particle diameter according to the present invention and a conventional one. FIG. 18 is a cross-sectional view of a two-fluid nozzle of an application example. FIG. 19 is a sectional view of a conventional two-fluid nozzle. FIG. 20 (A) is an explanatory view showing the particle size of a spray pattern of a nozzle for supplying a gas to an outer peripheral portion, centering on a liquid;
(B) is an explanatory diagram showing the particle size of a spray pattern of a nozzle that supplies a liquid to an outer peripheral portion, mainly of a gas. FIG. 21 is a sectional view of a conventional two-fluid nozzle. FIG. 22 is an enlarged view of a main part of FIG. 21. DESCRIPTION OF SYMBOLS 20 Nozzle body 25 Gas inlet 26 Liquid inlet 40a First wall 40b Second wall 40c Third wall 42a Single-hole discharge port 42b Porous discharge port A First mixing chamber B Rectifying chamber C Second Mixing chamber E Injection chamber O First axis

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-273565 (JP, A) JP-A-59-24560 (JP, A) JP-A-59-29055 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B05B ⁷ /00-7/32 B05B 1/00-1/36

Claims (1)

(57) [Claims 1] Along the axial center line at the base end side of the nozzle body.
To supply and mix the liquid around the periphery of the gas to be supplied
A mixing chamber is provided, and the mixing chamber communicates with the first mixing chamber.
A rectification chamber that allows the combined fluid to flow to the tip side along the axis
A second mixing chamber having a large diameter is provided on the tip side of the rectification chamber,
An injection chamber having a small diameter is provided at the distal end side of the second mixing chamber.
A passage between the distal end of the second mixing chamber and the distal end of the injection chamber;
In addition, the wall of the outer periphery of the mixed
On the other hand, through the injection chamber,
A circular single hole opened in the heart, constant around the above axis
A plurality of circular holes spaced at angular intervals, or
Spraying from the discharge port consisting of the combination of the above single hole and porous
A two-fluid nozzle characterized in that it is configured to perform the following.