JPH0960816A - Vaporizing combustor for liquid fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practical vaporizing combustion equipment which enables using thereof favorably for an industrial combustion chamber of a boiler or the like. SOLUTION: The combustion cylinder 3 comprises a primary combustion cylinder 11, a secondary combustion cylinder 12 and a tertiary combustion cylinder 13. A spray nozzle 4 or the like of a liquid fuel is arranged internally at an end part of the primary combustion cylinder 11. The tertiary combustion cylinder 13 is connected to a combustion chamber 2 communicating therewith. Primary combustion air 8a is supplied into the primary combustion cylinder 11 in a spiral flow at a primary combustion air supply port 17. Secondary combustion air 8b and tertiary combustion air 8c are supplied into the secondary combustion cylinder 12 and the tertiary combustion cylinder 13 respectively at a secondary combustion air supply port 18 and a tertiary combustion air supply port 19. An sprayed fuel from a spray nozzle 4 is burned by stages while being vaporized by a flame formed in the combustion cylinder 3 as heat source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device used in a combustion chamber of a boiler or the like, which is a vaporization type combustion device for vaporizing and burning a liquid fuel such as kerosene or heavy fuel oil A.

[0002]

2. Description of the Related Art A kerosene heater in which kerosene is vaporized and combusted by a vaporizer with a built-in heater is well known as a vaporization type combustion apparatus of this type. Nothing that can be used for industrial combustion chambers such as boilers has been put to practical use.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a practical liquid fuel vaporization type combustion apparatus that can be suitably used in an industrial combustion chamber such as a boiler. It is intended to provide.

[0004]

In order to achieve the above object, a liquid fuel vaporization type combustion apparatus of the present invention includes a primary combustion cylinder in which a liquid fuel spray nozzle, an ignition electrode, and a flame holding plate are arranged. A secondary combustion cylinder having a diameter larger than that of the primary combustion cylinder, which is connected to the primary combustion cylinder through the frustoconical first connecting cylinder so that its axis coincides with that of the primary combustion cylinder, and the secondary combustion cylinder and the axis thereof are connected to each other. Formed in a primary combustion cylinder and a tertiary combustion cylinder, which has a diameter larger than that of the secondary combustion cylinder, which are communicatively connected to each other through a second conical frustoconical connecting cylinder and are communicatively connected to the combustion chamber. A plurality of secondary combustion air that is formed in at least the first connection cylinder and a primary combustion air supply port that supplies the primary combustion air in a swirl flow into the primary combustion cylinder and that supplies the secondary combustion air into the secondary combustion cylinder. It is formed in the combustion air supply port and the second connecting cylinder or the secondary combustion cylinder, and the tertiary combustion is generated in the tertiary combustion cylinder. It comprises a, and tertiary combustion air supply opening for supplying air, which is constituted so as to stepwise combustion while the flames formed a fuel spray from the spray nozzle into the combustion cylinder is vaporized as a heat source.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to FIGS.

FIG. 1 shows an example in which a vaporization type combustion apparatus 1 according to the present invention is installed in a combustion chamber 2 of a boiler having an output of about 200,000 kcal / h and a relatively small capacity. In the following description, left and right means left and right in FIG. 1 for convenience.

That is, this vaporization type combustion apparatus 1 is shown in FIG.
As shown in FIG. 3, a combustion cylinder 3 in which a liquid fuel spray nozzle 4, an ignition electrode 5 and a flame holding plate 6 are installed is installed in a burner throat 2a of a combustion chamber 2 and a combustion air supply mechanism 10 is used to combust the combustion cylinder. 3, each combustion air supply port 17, 1 formed in this
It is configured to supply combustion air 8a, 8b, 8c from 8 and 19. The peripheral wall of the combustion chamber 2 including the side wall portion that opens the burner throat 2a has a hollow structure, and the inside thereof forms a can water region 2b.

As shown in FIGS. 1 to 3, the combustion cylinder 3 has a primary
Communicates with the combustion cylinder 11 and its right end through the first connecting cylinder 14.
The connected secondary combustion cylinder 12 and the second connecting cylinder 1 at its right end
It is composed of a tertiary combustion cylinder 13 which is communicatively connected to the third combustion cylinder 13.
Each combustion cylinder 11, 12, 13 has a concentric circular cross section.
And the inner diameter D of the secondary combustion cylinder 12₂Is the primary combustion cylinder 11
Inner diameter D₁Larger, inner diameter D of the tertiary combustion cylinder 13_ThreeIs two
Inner diameter D of the next combustion cylinder 12 ₂Larger setting (D
₁<D₂<D_Three). Primary combustion cylinder 11 and secondary combustion cylinder 12
Via the frusto-conical first connecting tube 14 that expands to the right
Are connected together. On the other hand, the tertiary combustion cylinder 13 is
Special independent members such as combustion cylinder 11 and secondary combustion cylinder 12
Use the burner throat 2a instead of the (metal cylinder)
It is configured. That is, as shown in FIG. 1, the secondary combustion
A second frustoconical second connection extending rightward at the right end of the cylinder 12.
The cylinder 15 is integrally formed, and the right end portion of the second connection cylinder 15 is
Fits on the left end of the burner throat 2a so that it can be inserted and removed in the axial direction.
By doing so, the burner slot on the right side of this fitting point
Part 2a of the valve to the secondary combustion cylinder 12 through the second connecting cylinder 15.
Then, the tertiary combustion cylinder 13 is communicatively connected. What
The combustion cylinders 11 and 12 and the connecting cylinders 14 and 15 are made of heat-resistant steel or the like.
It is made of heat resistant metal.

A burner plate 16 is attached to the left end of the primary combustion cylinder 11, and the spray nozzle 4, the ignition electrode 5, the flame holding plate 6 and the burner plate 16 are attached to the burner plate 16 as shown in FIGS. A flame detector 9 is attached. As shown in FIG. 3, the flame holding plate 6 is an annular plate having a circular hole 6 a at the center and an appropriate number of slits (about 8) formed in the outer peripheral portion thereof. They are arranged concentrically with an annular gap 6b formed between them and the inner peripheral surface. In the following description, the primary combustion cylinder 11
The portion on the left side of the flame holding plate 6 in the “first combustion cylinder portion 1
"1 ₁ " and the right part is "2nd combustion cylinder part 11 ₂ "
Say. The inner and outer diameters d ₁ and d ₂ of the flame holding plate 6 are generally
Area S ₁ of the center hole _{6a (= π (d 1)} 2/4) the area of the annular gap 6b between the inner peripheral surface of the primary combustion liner 11 S ₂
(= Π ((D ₁ ) ² − (d ₂ ) ² ) / 4) and S ₁ /
It is preferable to set (S ₁ + S ₂ ) <0.4 and set the flow velocity of the air passing through the center hole 6a and the annular gap 6b to 12 m / s or more (see FIG. 3). By doing so, the inner diameter D ₁ of the primary combustion cylinder 11 can be made relatively small, the amount of heat radiation from the primary combustion cylinder 11 can be made small, and the flame in the primary combustion section 11a can be further stabilized. Because you can. That is, when the inner diameter D ₁ of the primary combustion cylinder 11 becomes unnecessarily large, the amount of heat radiation increases, so that it is difficult to form a high-temperature flame on the downstream side (right side) of the flame holding plate 6, and the spray fuel from the spray nozzle 4 is generated. The heat source function of gasifying cannot be exerted. If the air velocity is less than 12 m / s, the flame may return to the spray nozzle 4 side. The spray nozzle 4 is of a hydraulic spray type that sprays liquid fuel such as kerosene, which is pressurized and supplied by a hydraulic pump, in the form of fine particles, and is arranged close to the flame holding plate 6 and concentrically with the central hole 6a. Has been done. As the spray nozzle 4, a return type hydraulic spray nozzle may be used instead of the hydraulic spray type. Generally, the axial distance h between the spray nozzle 4 and the flame holding plate 6 is preferably set to 2 to 10 mm. The ignition electrode 5 is arranged such that its discharge part is located in the vicinity of the spray port of the spray nozzle 4, and ignites the spray fuel by discharge.

By the way, in each of the combustion tubes 11, 12, 13
The diameter and the like are appropriately set according to the combustion conditions. For example,
Second combustion cylinder portion 11₂Axial length L₁Will be described later
So that the secondary combustion air 8b is supplied from the spray nozzle 4
This distance determines the axial distance to
Is important in forming a blue flame,
If this distance is too short, blue flame will not be formed, and conversely it will be too long.
And the flame becomes unstable. Therefore, the second combustion cylinder portion 1
1₂Length L₁Must be set in consideration of such points.
The second combustion cylinder portion 11 is generally required.₂Axis direction
Length L₁The inner diameter D of the primary combustion cylinder 11₁In relation to
0.9D₁≤L₁≦ 1.3D₁So that
Is preferred. In addition, the inner diameter of the secondary combustion cylinder 12 etc.
It is necessary to set according to such combustion conditions,
Generally, the inner diameter D of the secondary combustion cylinder 12₂And axial length
L₂Is the inner diameter D of the primary combustion cylinder 11.₁In relation to
1.3D₁≤D₂≦ 1.7D₁And inner diameter D
₂0.6D in relation to ₂≤L₂≤1D₂Will be
The inner diameter D of the tertiary combustion cylinder 13_Three(Or second series
The outer diameter of the right end portion, which is the maximum diameter portion of the connecting tube 15, is set to the secondary combustion tube 1
2 inner diameter D₂1.3D in relation to₂≤D_Three≤3.
0D₂It is preferable to set so that

As shown in FIGS. 1 and 2, a primary combustion air supply port 17 containing radial swirl vanes 17a is provided at the left end of the primary combustion cylinder 11 to swirl the primary combustion air 8a. After that, it is supplied into the primary combustion cylinder 11. That is, the primary combustion air 8a supplied from the primary combustion air supply port 17 forms a swirling flow along the inner peripheral surface of the primary combustion cylinder 11 and passes through the flame holding plate 6 from the first combustion cylinder portion 11 _1. It is adapted to be supplied to the second combustion cylinder portion 11 ₂ . The primary combustion air supply port 17
Are opened over the entire circumference of the primary combustion cylinder 11. Further, the primary combustion air supply port 17 including the swirl vanes 17a ...
In order to more effectively perform the mixing of the fine spray fuel from the spray nozzle 4 with the swirling flow of the primary combustion air and the formation of the circulating flow in the primary combustion part 11a, the structure of 1 It is preferable that a swirling air flow of about 2 can be supplied to the spray nozzle 4 and the flame holding plate 6 at 12 m / s or more.

As described above, when the primary combustion air 8a, which is smaller than the theoretical combustion air amount, is supplied to the first combustion cylinder portion 11 ₁ in a swirling flow, this is mixed with the spray fuel from the spray nozzle 4. Together with the formation of the negative pressure portion by the flame holding plate 6, a circulating flow is formed. The atomized fuel having a small diameter will be entrained in this circulating flow. Therefore, when the sprayed fuel from the spray nozzle 4 is ignited by the discharge of the ignition electrode 5, a high temperature flame is formed on the flame holding plate 6 to vaporize the sprayed fuel, and the sprayed fuel is vaporized in the second combustion cylinder 11 ₂ . The primary combustion section 11a is formed. That is, the primary combustion section 11
The flame formed in a is used as the vaporization heat source of the atomized fuel. At this time, when the supply amount of the primary combustion air 8a is excessive, the combustion mode in the primary combustion section 11a approaches the combustion mode of the normal liquid fuel burner, and the NOx generation amount increases. On the contrary, if the supply amount is too small, it is difficult to properly form the flame in the primary combustion portion 11a. Therefore, generally, the supply amount of the primary combustion air 8a is 30 to 50% of the theoretical combustion air amount.
(When the air ratio of the total combustion air supply amount is λ = 1.3)
It is preferable that The amount of NOx generated is such that there is no annular gap 6b between the outer peripheral end of the flame holding plate 6 and the inner peripheral surface of the primary combustion cylinder 11, and the primary combustion air 8a is primarily discharged from the center hole 6a of the flame holding plate 6. The presence of the annular gap 6 is important in reducing NOx, because the number of the annular gap 6 increases when it is supplied to the combustion section 11a.

As shown in FIGS. 1 to 3, the first connecting cylinder 14 is provided with a proper number of secondary combustion air supply ports 18, which are circular holes at equal intervals in the circumferential direction. Next combustion air 8
b is supplied into the secondary combustion cylinder 12. The diameter and the number of the secondary combustion air supply ports 18 ... Are set so that the supply amount of the secondary combustion air 8b is smaller than the theoretical combustion air amount. Generally, a plurality of secondary combustion air supply ports 18 having a diameter of 5 to 10 mm are formed at equal intervals in the circumferential direction, and the entire secondary combustion air supply port 1
The secondary combustion air supply amount from 8 is 30 which is the theoretical combustion air amount.
It is preferable to be set to ˜50% (when the air ratio of the total combustion air supply amount is λ = 1.3).

As described above, when the secondary combustion air 8b smaller than the theoretical combustion air amount is supplied to the secondary combustion cylinder 12, the secondary combustion section 12a is formed in the secondary combustion cylinder 12. In the secondary combustion section 12a, the combustion in the primary combustion section 11a is continued, the sprayed fuel vaporized in the primary combustion section 11a is burned, and a more effective vaporization action is performed. At this time, the secondary combustion cylinder 12 has a larger diameter than the primary combustion cylinder 11, and both cylinders 11 and 12 are connected by the first conical cylinder 14 having a truncated cone shape. Since the area expansion to 12a is gradual, the secondary combustion air 8b is uniformly supplied from the secondary combustion air supply ports 18 ... Evenly arranged in the circumferential direction in this expanded portion. Combined with this, the formation of a circulating flow is suppressed, soot adhesion is well prevented, and the secondary combustion air 8
The rapid combustion due to a is suppressed, and the generation of NOx is prevented as much as possible. Moreover, on the downstream side (right side) of the secondary combustion section 12b, the temperature of the combustion cylinder 3 itself rises due to the activation of combustion, and the vaporization of the spray fuel is promoted. That is,
The vaporization of the large-diameter atomized fuel that has passed through the primary combustion portion 11a without being vaporized and the further vaporization of the unburned gas are promoted.

By the way, from the secondary combustion air supply port 18 ...
Supply angle of secondary combustion air 8b into the secondary combustion cylinder 12 (fuel combustion
This is the supply angle with respect to the axis of the cylinder, the same applies below) α₁And the
1 Spreading angle of the connecting cylinder 14 (inclination angle with respect to the combustion cylinder axis)
Degree, same below) β₁A constant relationship (α₁
= 90 ° -β₁), But the angle α₁, Β₁Is above
In order to effectively carry out the actions described, the secondary combustion cylinder 12
Inner diameter D₂, Length L₂It is necessary to set in consideration of
is there. For example, the divergence angle β of the first connecting cylinder 14 ₁And axis
If the directional length becomes unnecessarily large, the combustion tubes 11, 12
Soot tends to adhere between the two. Therefore, in general
Is α₁= 30 ° ± 10 °, β₁= 60 ° ± 10 °
It is preferable to keep.

As shown in FIGS. 1 to 3, the second connecting cylinder 15 is provided with a plurality of tertiary combustion air supply ports 19 ... Circular holes at equal intervals in the circumferential direction. 8c
Is supplied into the tertiary combustion cylinder 13. The diameter and number of the tertiary combustion air supply port 18 and the second
The spread angle β ₂ of the connecting cylinder 15 and the supply angle α ₂ of the tertiary combustion air 8c are preferably set appropriately within the same range as in the case of the secondary combustion air port 18 and the first connecting cylinder 15 described above. . That is, the tertiary combustion air supply port 18
It is preferable that the diameter is 5 to 10 mm, the supply angle α ₂ is 20 to 40 °, and the spread angle β ₂ is 50 to 70 °. Further, the supply amount of the tertiary combustion air 8c is set to be smaller than the theoretical combustion air amount, but generally 30 to 50% of the theoretical combustion air amount (the air ratio of the total combustion air supply amount is λ
= 1.3) is preferable.

By supplying the tertiary combustion air 8c smaller than the theoretical combustion air amount to the tertiary combustion cylinder 13, the tertiary combustion section 13a is formed in the tertiary combustion cylinder 13.
In the tertiary combustion section 13a, the combustion in the secondary combustion section 12a is continued and the combustion in the secondary combustion section 12a is continued, including the vaporization of the sprayed fuel which is not sufficiently vaporized in the secondary combustion section 12a.
At, complete combustion of atomized fuel and unburned gas takes place. Moreover, due to the fact that the combustion cylinder 3 is red-heated, the blue flame is better formed. Further, the presence of the frusto-conical second connecting cylinder 15 makes the expansion of the region from the primary combustion part 11a to the secondary combustion part 12a gradual, so in this expanded part, in the circumferential direction thereof. Combined with the fact that the tertiary combustion air 8c is evenly supplied from the tertiary combustion air supply ports 19 that are evenly arranged, soot is well prevented from adhering, and rapid combustion by the tertiary combustion air 8c is suppressed. Thus, combined with the endothermic effect of the combustion furnace 2, NOx generation is suppressed extremely well. Such NOx reduction effect is mainly due to combustion air 8a, 8b, 8c extending from the primary combustion section 11a to the tertiary combustion section 13a.
Is gradually supplied to suppress local rapid combustion.

The combustion air supply mechanism 10 is, as shown in FIGS. 1 to 3, a wind box 20 attached to a can plate 2c forming the peripheral wall of the combustion chamber 2 and a combustion air supply pipe for supplying combustion air 8 to the wind box 20. And 21. The wind box 20 has a cylindrical outer peripheral wall 20a having a combustion air supply pipe 21 connected to its left end, and annular plate-shaped left and right side walls 20b, 20 fixed to its left and right ends.
c, a cylindrical first rectifier 20d that is concentric with the outer peripheral wall 20b and fixed to the right side wall 20c, and concentrically arranged between the outer peripheral wall 20a and the inner rectifying wall 20d and fixed to the left side wall 20b. The right side wall 20c is attached to the can plate 2c via an annular heat-resistant sealing material 22 in a state of surrounding the combustion cylinder 3 concentrically.
Therefore, in the wind box 20, the first passage 7a formed between the outer peripheral wall 20a and the second flow regulating wall 20e and the second flow regulating wall 20e and the first flow regulating wall 20d are formed. ,
The first rectifying wall 20e and the right side wall 20c are separated by the first gap.
The second passage 7b communicated with the passage 7a and the first straightening wall 20
d is formed between the combustion chamber 3 and the first commutation wall 20.
A series of combustion air rectifying passages 7 meandering in the left-right direction are formed by a third passage 7c that communicates with the second passage 7b through a gap between d and the left side wall 20b.

Thus, the combustion air supply pipe 21 is guided from the combustion air supply source, and the combustion air 8 having a predetermined flow rate is supplied to the wind box 2.
0, and the combustion air supply pipe 2
1 to the combustion air 8 supplied to the left end of the first passage 7a
Goes from the first passage 7a to the second passage 7b to the third passage 7c.
And each combustion air port 17, 1 communicating with the third passage 7c
It is supplied into the combustion cylinder 3 from 8 ..., 19 ...
Therefore, the combustion air 8 is rectified while flowing in the passage 7 in a meandering manner, and is uniformly supplied from the combustion air supply ports 17, 18 and 19 into the combustion cylinder 3. By thus rectifying the combustion air 8 and then supplying it to the combustion cylinder 3, a good flame is formed even in the case of low oxygen combustion. That is, when the combustion air 8 is supplied to the inside of the combustion tube 3 through the respective combustion air supply ports 17, 18, and 19 without being rectified, there is a possibility that the flame may be biased when low oxygen combustion occurs. .

By the way, the combustion air flowing in the third passage 7c is supplied into the combustion cylinder 3 through the respective combustion air supply ports 17, 18 and 19. That is, the third passage 7c
The combustion air introduced into the second combustion cylinder portion 11 ₂ from the primary combustion air supply port 17 through the first combustion cylinder portion 11 ₁ and the flame holding plate 6, that is, the primary combustion portion 11a is supplied as the primary combustion air. From the secondary combustion air supply port 18 to the secondary combustion unit 1
2a is supplied as secondary combustion air, and further supplied from the tertiary combustion air supply port 19 ... To the tertiary combustion section 13a as tertiary combustion air. Therefore, the combustion air 8a, 8b, 8c
Is supplied from the common combustion air rectifying passage 7 communicating with all the combustion air supply ports 17, 18 ..., 19 ..., the opening areas of these combustion air supply ports 17, 18 ..., 19 ... By appropriately setting, the amount of combustion air supplied from each combustion air supply port 17, 18, ..., 19 can be set in accordance with the combustion mode in each combustion section 11a, 12a, 13a as described above. it can.

The burner plate 16 is detachably attached to the left side wall 20b of the wind box 20 with its center hole closed. Therefore, by removing the burner plate 16 from the wind box 20, the combustion cylinder 3 except the tertiary combustion cylinder 13, the spray nozzle 4, the ignition electrode 5, and the flame holding plate 6 can be easily attached and removed together. Also,
The outer diameter of the right end portion of the second connecting cylinder 15 is such that the form of fitting to the burner throat 2a, that is, the form of connection between the secondary combustion cylinder 12 and the tertiary combustion cylinder 13 composed of the burner throat 2a, hinders predetermined combustion. The combustion cylinders 3 other than the tertiary combustion cylinder 13 are set so that they can be easily attached to and detached from the burner throat 2a in the axial direction on the condition that they are not present. Generally, it is preferable that the gap between the right end portion of the second connecting cylinder 15 and the burner throat 2a with which the second connecting cylinder 15 is fitted is 1 mm or less as a whole.

The present invention is not limited to the above-mentioned embodiment, and can be appropriately modified and improved within a range not departing from the basic principle of the present invention.

For example, the secondary combustion air supply ports 18 ... As shown in FIG. 4, the secondary combustion air supply ports 18 and the first connection cylinders 14 are circumferentially arranged at appropriate places (for example, the portions near the first connection cylinders 14). Alternatively, they may be formed at even intervals. In this case, it is preferable that each of the secondary combustion air supply ports 18 is a circular hole having a diameter of 5 to 10 mm.
The supply amount of the secondary combustion air 8b from 8 ... Is 30 to 50% of the theoretical combustion air amount, and the supply amount of the secondary combustion air 8b from each secondary combustion air supply port 18 is 15% of the theoretical combustion air amount.
It is preferable to keep the above.

Further, the tertiary combustion cylinder 13 may be constructed by utilizing the first straightening wall 20d of the wind box 20 as shown in FIG. That is, the second connecting cylinder 15 is fitted in the first straightening wall 20 d so as to be insertable and removable in the axial direction, and the first straightening wall portion on the combustion chamber 2 side from the fitting portion is configured as the tertiary combustion cylinder 13. Of course, the tertiary combustion cylinder 13 is not constructed by utilizing a part of the combustion chamber 2 or the wind box 20 as shown in FIG. 1 or FIG.
You may make it integrally connect with 2 through the 2nd connection cylinder 15. As shown in FIG. In addition, in the one shown in FIG. 5, the tertiary combustion air supply port 19 ... Which is a circular hole having a diameter of 5 to 10 mm is connected to the second connecting cylinder 1.
5, the secondary combustion cylinder 12 is formed in a suitable position (for example, a portion near the second connecting cylinder 15) in the circumferential direction and in the axial direction so as to be evenly arranged in parallel. When a large number of tertiary combustion air supply ports 19 ... Are formed in the secondary combustion cylinder 12 as described above, the NOx value is somewhat higher than when the tertiary combustion air supply ports 19 are formed in the second connection cylinder 15. However, high-load combustion becomes possible. Where confirmed by experiments,
Good combustion was obtained even at a furnace load of 6,000,000 kcal / m ³ h.

Further, the vaporization type combustion apparatus 1 according to the present invention is
Not only the combustion chamber 2 of the boiler, but also other industrial combustion chambers can be similarly used, and liquid fuel such as A heavy oil other than kerosene can also be used.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIGS. 1 to 3, combustion air supply holes 18 and 19 which are circular holes having a diameter of 10 mm are formed in the first and second connecting cylinders 14 and 15 at equal intervals in the circumferential direction. Installed, D ₁ = 68 mm, D ₂ = 96 mm, D ₃
= 140 mm, β ₁ = β ₂ = 60 °, d ₁ = 26 mm,
d ₂ = 60 mm and h = 6 mm. The vaporization type combustion apparatus 1 configured as described above is installed in the combustion chamber 2 as shown in FIG. 1, and when the air ratio is 1.3, 50% of the theoretical air amount of the primary combustion air 8a is supplied from the primary combustion air supply port 17. 12m /
The secondary combustion air 8b and the tertiary combustion air 8c of 40% of the theoretical air amount are supplied to the primary combustion cylinder 11 in the form of a swirl flow of s or more, and the secondary combustion air supply port 18 ... And the tertiary combustion air supply port 19 ... From α ₁ = α ₂ = 30 °, the secondary combustion cylinder 1
8 kg / cm ² supplied to the secondary and tertiary combustion cylinders 13
The kerosene pressurized to was supplied to the spray nozzle 4, and 18 kg / h of kerosene was sprayed from the spray nozzle, ignited by the discharge of the ignition electrode 5, and vaporized and burned.

When the combustion state was observed, although a slight yellow flame was observed at the center of the combustion cylinder 3, the combustion cylinder 3
Good blue flame formation was confirmed inside and at the outlet.

Further, at three points A, B and C in the axial direction of the combustion cylinder 3, the temperature (° C.) and NOx at the five positions a, b, c, d and e in the radial direction of the combustion cylinder 3 respectively.
The generated amount (ppm (O ₂ = 0% conversion)) was measured (at the position e, only the temperature at the position C was measured). The result is as shown in FIG. 6, which shows that the vaporizing combustion action described above is performed, and in particular, local rapid combustion is suppressed and N
It was confirmed that the amount of Ox generated was extremely small. In FIG. 6, the numbers in parentheses for each NOx are O ₂
%. Further, the position a is a position on the center line of the combustion cylinder 3, and the positions b to e are positions that divide the radius of the secondary combustion cylinder 12 into five equal parts. In addition, the scales (vertical axis) of the temperature and NOx generation amount at each location A, B, C are based on the axial position at that location (0 ° C., 0 ppm (O ₂ = 0% conversion))
It is assumed that.

Furthermore, the exhaust gas at the outlet of the combustion chamber 2, NOx generation amount with respect to O _2% (ppm (O ₂
= 0% conversion)), CO generation amount (ppm), and small scale number (which is a main index of the dust generation rate, and hereinafter referred to as "SS No.") were measured. The results are shown in FIG. 7, and it was confirmed that there was no problem in terms of exhaust gas characteristics. 7, the solid line indicates the NOx generation amount, the chain line indicates the CO generation amount, and the broken line indicates SSNo. Are shown respectively. By the way, the NOx value tends to decrease as the O ₂ % increases, but such NOx characteristics are found in the premixing (former mixing) of the gas fuel, and also from this fact, good vaporized combustion is performed. It is understood that

[0030]

As is apparent from the above description, since the liquid fuel vaporization type combustion apparatus of the present invention vaporizes and burns liquid fuel such as kerosene or heavy fuel oil A, it enables high load combustion. , Industrial combustion chambers, especially output 1,000,00
It can be suitably used for a combustion chamber such as a boiler having a relatively small capacity of about 0 kcal / h or less. In addition, since it uses the heat of self-combustion as a vaporization heat source for liquid fuel,
It requires no special carburetor, and can be handled in the same manner as a general industrial combustion device (burner) that uses liquid fuel for load fluctuations. Moreover, since the primary combustion air, the secondary combustion air, and the tertiary combustion air are supplied in stages to burn, the local rapid reaction of the combustion itself is suppressed,
The amount of generated NOx can be reduced. Furthermore, in combination with the fact that a vaporizer is not required separately, the structure can be simplified and the size can be reduced, and the practical value thereof is extremely large.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing a liquid fuel vaporization combustion apparatus according to the present invention.

FIG. 2 is a detailed view showing an enlarged main part (combustion cylinder excluding a secondary combustion cylinder) of FIG.

3 is a cross-sectional plan view taken along the line III-III in FIG.

FIG. 4 is a vertical sectional side view corresponding to FIG. 2 showing a modified example.

FIG. 5 is a vertical sectional side view corresponding to FIG. 1 showing another modification.

FIG. 6 is an explanatory diagram showing the relationship between the measurement result of the temperature and the NOx generation amount in the combustion cylinder and the measurement position thereof.

FIG. 7 is a graph showing exhaust gas characteristics at the outlet of the combustion chamber.

[Explanation of symbols]

1 ... Evaporative combustion device for liquid fuel, 2 ... Boiler combustion chamber,
3 ... Combustion cylinder, 4 ... Liquid fuel spray nozzle, 5 ... Ignition electrode, 6 ... Flame holding plate, 7 ... Combustion air rectifying passage, 8 ... Combustion air, 8a ... Primary combustion air, 8b ... Secondary combustion air, 8c …
Tertiary combustion air, 10 ... Combustion air supply mechanism, 11 ... Primary combustion cylinder, 11 ₁ ... First combustion cylinder part, 11 ₂ ... Second combustion cylinder part, 11a ... Primary combustion part, 12 ... Secondary combustion cylinder, 12a ...
Secondary combustion part, 13 ... tertiary combustion cylinder, 13a ... tertiary combustion part,
14 ... 1st connection cylinder, 15 ... 2nd connection cylinder, 17 ... Primary combustion air supply port, 18 ... Secondary combustion air supply port, 19 ... Tertiary combustion air supply port, 20 ... Wind box.

Claims (1)

[Claims] 1. A primary combustion cylinder in which a liquid fuel spray nozzle, an ignition electrode and a flame holding plate are internally disposed, and a primary combustion cylinder communicates with the primary combustion cylinder through a frusto-conical first connecting cylinder. The secondary combustion cylinder connected to the secondary combustion cylinder has a diameter larger than that of the primary combustion cylinder, and the secondary combustion cylinder is communicatively connected to the secondary combustion cylinder through a second connecting cylinder having a truncated cone shape with its axis aligned. A primary combustion air supply port, which is connected to each other and is formed in a primary combustion cylinder and a tertiary combustion cylinder having a diameter larger than that of the secondary combustion cylinder, and which supplies primary combustion air in a swirl flow into the primary combustion cylinder, and at least First
A plurality of secondary combustion air supply ports formed in the connecting cylinder to supply the secondary combustion air into the secondary combustion cylinder and a second connecting cylinder or the secondary combustion cylinder to form a tertiary combustion inside the tertiary combustion cylinder. A tertiary combustion air supply port for supplying combustion air is provided, and the spray fuel from the spray nozzle is configured to be burned stepwise while being vaporized by using a flame formed in the combustion cylinder as a heat source. Liquid fuel vaporization type combustion device.