JPS6349613A - Intermixing type atomizer - Google Patents

Abstract

PURPOSE:To accomplish a high efficient and low NOx combustion and enable a scale-up operation to be performed by a method wherein partition plats dividing in the circumferential direction an interior of a mixing chamber communicating with injection holes according to positions of injection holes and the number of injection holes are arranged within the mixing chamber. CONSTITUTION:Divisional partition plates 11 arranged within a mixing chamber 7 are inserted according to positions and the number of injection holes 8. An axial length of each of the divisional partition plates 11 for a burner is set to have about 3/4 of a length of the mixing chamber from a side end of a furnace in order to decrease a pressure loss. Since a severe contact occurs within the mixing chamber 7 (in particular, at surfaces of the divisional partition plates), it is preferable to mold the divisional partition plates 11 with ceramics. Fuel primarily divided into fine particles at gas-liquid striking holes 6 is injected into the mixing chamber 7 and since there are divisional partition plates 11, the fuel and the fine particle medium are uniformly distributed to each of the injection holes 8. That is, approximately the same amount of fuel is injected from each of the injection holes 8 in a substantial equal fine particled condition (injection means particle diameter or distribution of viscosity is approximately the same).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an internal mixing type atomizer, and particularly an internal mixing type atomizer suitable for achieving high efficiency and low pollution combustion of slurry fuel containing fine powder solids. Regarding.

[Conventional technology]

CWM (Highly Concentrated Coal/Water Slurry) is a fluidized fuel that can be sprayed and burned using an atomizer in the same way as conventional oil. It is known that the amount of unburned substances increases. The reason for the poor ignitability is that heat is consumed in evaporating water, and the ignition distance is considerably longer than that of pulverized coal. In addition, although there are many unknown reasons for the increase in unburned coal, it is likely that the tiny coal particles are agglomerated within the droplets and are not burnt out as individual particles like pulverized coal. This is because moisture lowers the combustion temperature. Furthermore, as a characteristic of coal combustion, it is difficult to suppress NOx due to its poor flame stability and the formation of a stable reduction zone when the flame lifts (it does not reach high temperatures). This also applies to Therefore, in order to increase the combustion efficiency of CWM to the level of pulverized coal, it is necessary to develop an atomizer that has excellent spray performance and is suitable for CWM combustion.

FIG. 10 is a sectional view showing the structure of a typical conventional two-fluid atomizer.

Figure 10 shows an example of an internal mixing type, in which the CWM is connected to the nozzle 8.
At the bottom of the atomizer chip main body 1, there are a fuel nozzle 4 for introducing the fuel 2, an atomization medium supply hole 5 for introducing the atomization medium 3, and a gas-liquid collision hole for mixing the fuel 2 and the atomization medium 3. 6 and supplies the mixture to the mixing chamber 7 of the main body 1, and the main body 1 is integrally connected to this plate IO by a camping napht 9.

In the atomizer shown in FIG. 10, the fuel 2 and the atomization medium 3 are mixed together in the gas-liquid collision hole 6 opened at the center of the intermezzoate plate 10 to perform primary atomization, and then in the mixing chamber 7. After being retained, it is atomized and injected from the nozzle 8.

Regarding this type of device, see Proceedings of the 13th Lecture on Liquid Atomization (August 1980), p. 41, Mitsubishi Heavy Industries Branch Vo 1.22. No.

5 (1985-9) 664 pages, Ishikawajima Harima Heavy Industries Branch Axis V
o1.25. No. 5 (1985-9) 308.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not give consideration to achieving equal distribution of fuel from each nozzle hole in the atomizer and homogeneous atomization, and also to increasing the capacity (scale amplifier), resulting in unbalanced combustion. This made zone control difficult, making it impossible to reduce not only unburned content in the ash but also NOx. Furthermore, there was a problem in that the above-mentioned drawbacks became more noticeable as the scale was increased.

The purpose of the present invention is to solve the problems of the prior art described above,
The object of the present invention is to provide an internal mixing atomizer that achieves high efficiency and low NOx combustion and can be scaled up.

[Means for solving problems]

In order to achieve the above object, the present invention is an internal mixing type atomizer that mixes fuel and atomized medium within the atomizer, but communicates with the nozzle and the position of the nozzle in the circumferential direction within the mixing chamber. A partition member is provided in the mixing chamber to divide the mixing chamber according to the number of the mixing chambers.

[Effect]

A partition member provided in the mixing chamber distributes the gas and liquid supplied to each ejection hole so that the flow rate becomes equal. The fuel injected from each nozzle is atomized so that combustion is not uneven.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on the drawings.

1, 2, and 3 are a cross-sectional view, a cross-sectional view taken along the line A-A, and a plan view showing one embodiment of the present invention. In FIG. 1, the same parts as in FIG. 10 are indicated by the same reference numerals, so a duplicate explanation will be omitted, but the mixing chamber 7 is constructed by providing a dividing partition plate 11. This divided partition plate 11 is
They are inserted in accordance with the position and number of the ejection holes 8. The length of the partition plate 11 in the burner axial direction can be made to match that of the mixing chamber 7, but here it is set to about 3/4 of the length of the mixing chamber from the furnace side end in order to keep the pressure loss low. The inside of the mixing chamber 7 (especially the surface of the dividing partition plate) is a place where the contact between gas and liquid is quite intense, so the dividing partition vi
11 is desirably formed of a wear-resistant and heat-resistant member such as ceramics.

FIG. 4, FIG. 5, and FIG. 6 are a cross-sectional view, a cross-sectional view taken along the line B-B, and a plan view showing other embodiments of the present invention.

In this embodiment, a multi-hole nozzle 12 is provided in the mixing chamber 7 in place of the dividing partition plate 11 in the previous embodiment. It is preferable that the multi-hole nozzle 12 be formed of ceramic for the same reason as in the above embodiment.
The diameter of the 0-divided nozzle hole 13 is larger than that of the jet hole 8 in order to reduce pressure loss and achieve stable injection. A recess 14 is formed to face the gas-liquid ejection hole 6 for the purpose of increasing the contact area of the gas-liquid spray flow and creating an appropriate circulating flow.

Next, the effects of the configuration of each of the above embodiments will be explained.

The fuel that has been atomized primarily in the gas-liquid collision hole 6 is injected into the mixing chamber 7, but in the embodiment shown in FIG. 1, the divided partition plate 11 is used, and in the case of FIG. Therefore, fuel and atomization medium are evenly distributed to each ejection hole 8.

That is, approximately the same amount of fuel is sprayed from each nozzle hole 8 in approximately the same atomized form B (spray average particle size and viscosity distribution are approximately the same). The results of confirming this effect are shown in the seventh section.
Each nozzle 1 in FIG. 7(A) shown in FIGS. (A) and (B)
The numbers ˜6 correspond to the numbers shown on the horizontal axis of FIG. 7(B). From Fig. 7 (B), when no partition device is provided (conventional example), fuel tends to be biased toward the lower nozzle holes (especially the N014 nozzle hole) due to the action of gravity inside the mixing chamber 7. . Therefore, in the ejection hole 8 where fuel is in excess, the gas-liquid ratio decreases relatively, and the flame becomes longer due to deterioration of atomization.

FIG. 7(B) shows that due to the action of the atomizer of the present invention,
This indicates that the above drawbacks are largely resolved.

Furthermore, the number of gas-liquid contact areas, ie, high shear areas, on the solid surface increases by the inner wall surface of the dividing partition plate 11 or the dividing nozzle 12, which improves atomization.

From the above, the effects of using the atomizer of the present invention can be summarized into the following two points.

■ Since the particles are evenly atomized from each nozzle, mixing with combustion air is improved without uneven distribution.

■ Flame stability is improved by promoting atomization.

These two effects make it possible to simultaneously reduce nozzles and unburned matter in coal slurry fuel. Demonstration examples are shown in Figures 8 and 9. By using the atomizer of the present invention, it is possible to reduce NOx by approximately 1100 pp and unburned matter by approximately 2% compared to conventional atomizers. Become.

In the combustion of coal, most of the generated NOx is fuel NOx resulting from conversion of the nitrogen content. In this case, strengthening flame holding is most effective for simultaneously reducing unburned content and NOx. In particular, the atomizer of the present invention can be applied to a wide range of coal types with various properties, since the low-quality coal has a high fuel ratio (mass ratio of residual solid combustible content/volatile combustible content). .

The atomizer according to the present invention is not limited to the above-mentioned CWM,
It is applicable to almost all other liquid or fluidized fuels. Here is an example.

(1) Light oil, A, B, C heavy oil (2) COM (coal/oil slurry) (3) Methanol (coal, methanol slurry) (4) P
WN (Petroleum coke, water slurry) (5) Pinch, water slurry (6) Poor quality residue (e.g. straight asphalt) Among these, (2) to (5) are slurry fuels, and CWM
Similarly, since it can be said to be relatively flame retardant, the atomizer of the present invention can be expected to have an effect of improving flammability.

Further, according to the present invention, since ignition can be stabilized,
Not only flying ash (EP ash) but also A/H
Combustion efficiency is improved because the unburned content of cinder ash and ash from the furnace can be reduced. Furthermore, since the amount of atomization medium ('Fi gas) can be reduced, boiler efficiency can be increased and auxiliary equipment power costs can be reduced. In addition, low-excess air combustion becomes possible, making it possible to prevent low-temperature corrosion even when using coal with a high sulfur content.In addition, by improving ignitability, high-fuel ratio coal (fuel It is also advantageous for slurry fuels using the ratio = fixed carbon/volatile content).

〔Effect of the invention〕

As described above, according to the present invention, since the flame flow pattern can be made axially symmetrical, it is possible to increase the capacity (scale up).

[Brief explanation of the drawing]

1, 2 and 3 are a sectional view, a sectional view and a plan view taken along the line A-A, and FIGS. 4 and 5, showing a first embodiment of the invention.
5 and 5 are cross-sectional views showing a second embodiment of the present invention, B
-B arrow sectional view and plan view, Figures 7 (A) and (B) are explanatory diagrams of the spray dispersion pattern in the present invention, Figures 8 and 9 are NOx and unburned fraction characteristic diagrams in the present invention , 1st
FIG. 0 is a sectional view showing a conventional internal mixing type atomizer. 1... Atomizer chip body, 7...
Mixing chamber, 8...Blowout hole, 10...Intermezoate plate, 11...Dividing partition plate, 12...Multi-hole nozzle, 13... ...Divided nozzle hole, 14 ... recess. Agent Patent Attorney Masaru Nishimoto - Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 (B) Note 1 Figure 8 ex, o2 (%) Figure 9 ex, o2 (%) Figure 10 Procedural master's official document (method) % formula % 2. Name of the invention Internal mixing atomizer 3. Relationship with the person making the amendment Patent applicant's address Ote, Chiyoda-ku, Tokyo Town 2-6-2 Name
(544) Babcock Hitachi Co., Ltd. 4, Agent
■160 Address: 1986, 7-3-10 Nishi-Shinjuku, Shinjuku-ku, Tokyo
October 8, 2015 6, column for a brief description of the drawings in the specification subject to amendment. 7. Contents of the amendment (1) In the 5th line of page 11 of the specification, ``Figures 5 and 5 are changed to ``Figures 5 and 6''.

Claims (3)

[Claims] (1) A fuel supply path and an atomization medium supply path for atomizing the fuel, a mixing chamber for mixing the fuel supplied from the fuel supply path and the atomization medium supplied from the atomization medium path, and a mixing chamber for mixing the fuel supplied from the fuel supply path and the atomization medium supplied from the atomization medium path. In the atomizer, a partition member is provided in the mixing chamber that divides the mixing chamber communicating with the ejection hole in a circumferential direction according to the position and number of the ejection holes. An internal mixing atomizer characterized by being provided with. (2) The internal mixing type atomizer according to claim 1, wherein the partition member is comprised of a plurality of plate-shaped bodies extending in a radial direction from the axial center of the mixing chamber. (3) Claim (1) characterized in that the partition member is a multi-hole nozzle in which nozzle holes having a diameter larger than the diameter of the jet holes are provided opposite to each of the jet holes. Internal mixing atomizer as described in section.