KR960012387B1 - Combustion device - Google Patents

Abstract

None.

Description

[Name of invention]

Combustion device

[Brief Description of Drawings]

1 is a cross-sectional view of a combustion apparatus in one embodiment of the present invention.

2 is an enlarged cross-sectional view of a flame hole of the combustion device.

3 is a cross-sectional view showing the overall configuration of the combustion device.

4 is a sectional view showing the main parts of a burner head according to another embodiment of the present invention.

Fig. 5 is a main sectional view showing the burner head portion similarly in still another embodiment.

6 is a cross-sectional view of a conventional combustion device.

Detailed description of the invention

[Technical Field]

The present invention relates to a premixed combustion apparatus for use in petroleum fan heaters and the like.

[Background]

Conventionally, this type of combustion apparatus is fitted with a cylindrical burner head 23 which is ceiling-mounted on the upper opening of the gas cylinder 22 in which a seed hester 21 is embedded, as shown in FIG. And a gas mixture of vaporized fuel and combustion air supplied and vaporized in the vaporization cylinder 22 is led into the burner head 23, and is formed from a plurality of flame holes 24 formed over the entire circumferential wall thereof. It blows out and forms the flame 26 through the metal mesh 25. FIG. In the drawing, reference numeral 27 denotes a nozzle for supplying fuel into the vaporization cylinder 22, 28 a blower tube for supplying combustion air into the synchronization cylinder 22, and 29 a blower tube 28 and a vaporization cylinder 22. The throat (30) connected to the throat (throat) is a gas cylinder cover having a mixed gas inlet (30a), (31) a resistance plate having a plurality of holes, (32) a barrel having an opening (32a), ( 33 is an ignition electrode, and 34 is a frame rod as a flame detection sensor.

[Problems that the invention tries to solve]

In the conventional combustion apparatus, each flame hole 24 formed in the burner head 23 is formed in a long elongated shape of 3 mm x 10 mm, and its single opening area is large. This is because the conventional combustion apparatus was not too aware of the combustion variation and was simply determined according to the maximum combustion amount of the combustion apparatus. Therefore, in such a conventional combustion apparatus, the amount of nitrogen oxides (NOx) is emitted and the burn down ratio is also narrow to 3200 to 1100 kcal / h.

That is, when the volume of the flame 26 formed in the flame hole 24 is a certain level or more, the flame temperature also becomes high in proportion to the flame volume, resulting in a higher flame temperature. Therefore, NOx which is highly dependent on the flame atmosphere temperature was high.

In addition, when the minimum combustion amount is lowered in order to enlarge the variable width of the minimum combustion amount and the minimum combustion amount, the flame 26 is in close contact with the flame hole 24 and the temperature of the upper metal mesh 25 is increased to increase the heat resistance of the metal mesh itself. There was a problem and there was also the possibility of backfire, so it was not possible to expand the combustion variability.

For this reason, it was conceived to respond by increasing the flame hole load by reducing the single flame hole area. However, the countermeasure is easy to lift due to a slight variation in the air-fuel ratio during minimum combustion, and the flame holding force of the flame 26 is weakened. At the same time, there has been a problem that the temperature of the gasification cylinder 22 greatly affected by the flame 26 is lowered, which adversely affects the vaporization performance of the fuel.

[Initiation of invention]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to increase the combustion variable width and to obtain good vaporization and combustion performance while suppressing the emission of NOx.

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, in the first invention, a plurality of flame holes of the burner head are formed in a plurality of stages of three or more stages in the vertical wall in the entire area of the circumferential wall, and at the same time, The flame hole, which is located in the lower part of the circumferential wall, is a through hole slightly larger than the micro-permeable hole, and the porous plate body of the metal net is in close contact with the outer circumference of the burner head. In the second invention, a plurality of flame holes of the burner head are formed in the entire area of the circumferential wall over the multi-stage of at least three stages so that the opening outside the burner head is larger than the inner opening, and is located above the circumferential wall. The inner opening of the flame hole is a micro-perforation hole, and the inner opening of the flame hole located in the lower part of the wall is slightly smaller than the micro-hole. It is made by making a large perforation hole, and making porous plate bodies, such as a metal mesh, to adhere to the outer periphery of the burner head of the said burner head.

In the first aspect of the present invention, since the single opening area of the flame hole is small in the first aspect of the present invention, the flame volume is small and the flame temperature is also lowered, and the emission of NOx is suppressed. Further, by constructing the flame hole in the upper part of the burner head at which the metal mesh temperature becomes high by the small flame hole, the blowing flow rate of the mixed gas increases, and the flame volume gradually decreases, thereby lowering the metal mesh temperature.

In addition, the lower flame hole of the burner head, which tends to be weaker in flame holding force, is used as the flame hole slightly larger than the upper flame hole, thereby lowering the blowing flow rate with the mixed gas, and also increasing the flame holding force as a small but relatively large flame volume. Therefore, the heat recovery to the vaporization cylinder is improved, so that the temperature decrease of the vaporization cylinder can be prevented, so that good vaporization and combustion performance can be obtained.

In the second invention, the flame opening formed in the burner head is regulated by the micro-perforated hole formed in the inner side of the burner head, so that the flame volume formed therein is also reduced, and the emission of NOx is further reduced. Will be. In addition, since each of the flame holes has a slightly larger through hole on the outer periphery of the micro through hole, the flow rate decreases at a portion of the slightly larger through hole formed in the micro through hole. It is attached to the flame state. Therefore, a very strong flame holding flame is formed, and the flame velocity is increased at the central portion of the flame hole other than the hole edge so that the flame velocity is larger than that of the hole edge. Even disappear.

In addition, since each of the flame holes of the burner head is a flame hole whose lower flame hole is slightly larger than the upper flame hole, the flame formed in the lower flame hole located near the gas cylinder can be discharged due to the above-described lowering of the flow velocity. The flame retention is increased, thereby facilitating heat recovery from the burner head to the gasification cylinder, thereby suppressing a decrease in the gasification cylinder temperature caused by the expansion of the combustion variable width (lowest amount of the minimum amount), thereby obtaining good vaporization and combustion performance.

Best Mode for Carrying Out the Invention

An embodiment of the present invention will be described below by taking the case where the burner head has a double configuration.

In Figs. 1 to 3, (1) is a bottomed cylindrical vaporization cylinder with an open top, in which a seed heater is embedded. (3) is a ceiling-shaped burner head which is screwed by mounting the flange portion of the lower peripheral edge on the opening edge portion 1a of the vaporization cylinder 1, the outer second burner head 3a. And the inner first burner head 3b pressed into the upper side thereof. The outer second burner head 3a has slightly larger through holes 4a, 4b, 4c in the order of 3 mm, 3.5 mm, and 4 mm in diameter from the top to the bottom of the circumferential wall. The inner first burner head 3b is also formed with micro-permeable holes 5a, 5b, and 5c in the order of 1.5 mm, 1.8 mm, and 2.6 mm in diameter from the top to the bottom of the entire circumferential wall. These transmission holes are formed coaxially and set to face each other to form flame holes 6a, 6b, and 6c. (7) is a metal net provided in the outer periphery of the said outer 2nd burner head 3a, and spot-welded between the lower permeation holes 4c of the whole perimeter wall.

(8) is a vaporization cover which covers the opening part of the said vaporization cylinder 1 provided in the burner head 3, The center core opening is made small diameter, and it is set as the mixed gas inlet 8a. (9) is a pressure plate fixed to the burner head (3) as a resistance plate in which a number of small holes are drilled at a position opposite to the mixed gas inlet (8a) of the vaporization container cover (8). Denoted at 10 is an ignition electrode for igniting the mixed gas ejected from the flame holes 6a, 6b and 6c, 11 is a flame, and 12 is a frame rod as a flame detection sensor. 13 is a blower tube for sending combustion air to the inside of the vaporization cylinder 1, the air hole 14 of the front end portion 13a is formed on the wall surface of the vaporization cylinder 1, the other side of the blower 15 ) Is communicating. Numeral 16 denotes a nozzle in communication with the oil supply pipe 18 from the fuel pump 17, and is directed to the inside of the vaporization cylinder 1 through the air blower tube 13.

In the above configuration, when the sheet heater 2 is energized and the vaporization cylinder 1 is heated to a predetermined temperature, the blower 15 is started so that combustion air passes through the blower tube 13 from the air outlet 14. It is sent to the inside of the vaporization cylinder 1, the fuel pump 17 is also started, and fuel passes through the oil supply pipe 18, and is ejected from the nozzle 16 into the vaporization cylinder 1 inside. The liquid fuel ejected into the vaporization cylinder 1 is vaporized at the side wall surface of the heated vaporization cylinder 1, mixed with the combustion air, and then sent to the burner head 3, where the flame holes 6a and 6b are provided. And ejected from (6c). The mixed gas is then ignited by the spark discharge from the ignition electrode 10 to form the flame 11. At this time, the mixed gas rises along the circumferential wall of the vaporization cylinder 1 and flows from the mixed gas inlet 8a at the center of the vaporization cylinder cover 8 to the burner head 3, so that even if there are relatively large unvaporized particles, It does not enter the burner head 3 as it is, and can suppress the yellow flame which arises from the occurrence of relatively large micro-particles. In addition, the mixed gas from the mixed gas inlet 8a is dispersed by the resistance plate 9 so as to be almost uniformly dispersed in the burner head 3, thereby suppressing the blurring of the flame.

Here, the flames formed in the flame holes 6a, 6b, and 6c of the burner head 3 are substantially the minute of the inner first burner head 3b whose flow rate and flow rate are inward. Since it is regulated by the through holes 5a, 5b, and 5c, the flame volume is very small.

Therefore, since the flame temperature is also lower than the conventional flame and the flame length is shortened, the ambient temperature around the burner can be reduced as much as possible. Therefore, a combustion state with a low flame atmosphere temperature can be obtained, and generation of NOx whose emission is highly dependent on the flame temperature can be suppressed.

Each of the flame holes is a slightly larger through hole 4a, 4b, 4c of the second burner head 3a on the outside of the minute through holes 5a, 5b, and 5c. As a result, the flames formed in the micro-permeable holes 5a, 5b, and 5c cause a decrease in flow velocity in the slightly larger through-holes 4a, 4b, and 4c. The flame state attached to the hole edges of the holes 4a, 4b, and 4c is obtained. As a result, a very strong flame holding flame is formed, and at the center of the flame hole other than the hole edge, there is no flow rate drop due to wall sticking phenomenon such as the hole edge, so that the flame flow rate is increased, so that the temperature of the metal mesh 7 rises much. In addition, there is no backfire as well as flame instability due to the expansion of the combustion variable width.

In addition, each of the flame holes 6a, 6b, and 6c inside and outside the burner head is a flame hole 6a6b6c whose lower flame hole is slightly larger than the upper flame hole. Since the mixed gas collides with the ceiling wall of the burner head 3 and spreads throughout the entire circumference, the blowing pressure of the mixed gas tends to increase as the flame hole in the upper portion thereof. Therefore, the ejection flow velocity of the mixed gas from each flame hole is lower in the upper part and lower in the lower part. Therefore, since the flame formed in the lower flame hole located near the vaporization cylinder 1 has a slow flow rate and a relatively large flame volume, its flame holding property is increased. The heat recovery of 1) can be promoted, and the decrease in the gas cylinder temperature caused by the expansion of the combustion variable width (the minimum combustion amount decrease) can be suppressed, so that good vaporization and combustion performance can be obtained, and the tar resistance Improvement can be aimed at.

In addition, the upper flame hole of the burner head 3, where the temperature of the metal chamber 7 tends to become high, has a high flow velocity of the mixed gas, and the volume of the flame in this portion is small, so that the temperature of the metal mesh 7 also decreases. It is possible to provide a burner having high heat resistance.

4 shows the case where the burner head 3 is heavy, and the flame holes 6a, 6b, and 6c of the burner head 3 are located at the outer side of the second burner head. The circumferential opening is formed in multiple numbers in the entire circumferential wall area of the circumferential wall so as to be larger than the circumference of the inner first burner head, and at least the inner circumferential opening of the flame hole located above the circumferential wall is At least, the at least inner circumferential opening of the flame hole located above the circumferential wall is a flame hole 6a6b6c which is slightly larger than the micro through hole. The effect is the same as in the above-described embodiment.

5 shows the case where the burner head 3 is single, but in the case of the burner head 3, each flame hole has a single diameter hole, and each of the flame holes 6a, 6b, 6c is a flame hole 6a6b6c in the upper part and a slightly larger flame hole in the lower part. Also in this case, the flame hole in the upper part of the burner head 3 which tends to increase the metal mesh temperature can increase the blowing flow rate of the mixed gas and decrease the flame volume, thereby lowering the metal mesh temperature. In addition, the lower flame hole of the burner head 3, which tends to be weak in flame holding force, also has a lower flow velocity of the mixed gas and a relatively large flame volume, thereby making it possible to strengthen the flame holding force. In this way, the heat recovery is improved, so that the temperature decrease of the vaporization cylinder 1 can be prevented, thereby obtaining good vaporization and combustion performance. Other functions and effects are the same as those of the first embodiment except for stabilization of the flame.

In addition, each of the above embodiments is shown as an example to effectively commercialize the present invention, the configuration of the details are not limited to the shape of the embodiment, for example, the burner head is to close the bottomless cylindrical parts and the ceiling It may be comprised by the two-part component with a ceiling wall part, and may be comprised in what form, if the objective and effect of this invention are achieved.

Industrial availability

As described above, the combustion apparatus of the present invention can expand the combustion variability by increasing the flame holding power of the flame while suppressing the generation of nitrogen oxides, and also increases the flashback, the increase in the metal mesh temperature, It is possible to provide a high-performance burner that can prevent the lowering of the vaporization barrel temperature, and which has high safety and good vaporization performance.

Claims (6)

A vaporization cylinder 1 that vaporizes liquid fuel and mixes this vaporization gas with combustion air to produce a mixed gas, and a burner head that ejects and combusts the mixed gas generated in the vaporization cylinder 1 from a plurality of flame holes. (3), the flame hole of the burner head (3) is multiplied in multiple stages of three or more stages up and down in the entire circumferential wall area, and the flame hole located above the circumferential wall is a micro-perforated hole, The flame | dye hole located in the lower part of a wall is a penetration hole slightly larger than the said micro-permeable hole, and the combustion apparatus provided by bringing a porous plate body (7), such as a metal mesh, in close contact with the outer periphery of the circumferential wall of the burner head. A vaporization cylinder 1 for vaporizing liquid fuel and mixing the vaporization gas with combustion air to generate a mixed gas, and a burner head for ejecting and combusting the mixed gas generated in the vaporization cylinder 1 into a plurality of flame holes for combustion. (3), the flame hole of the burner head (3) is a multistage of at least three steps in the vertical wall in the entire area of the circumferential wall so that the opening inside the burner head (3) is larger than the opening outside the burner head (3). At the same time, the inner opening of the flame hole located in the upper part of the circumferential wall is a micro-perforated hole, and the inner opening of the flame hole located in the lower part of the circumferential wall is a slightly larger-sized through hole. A combustion apparatus in which a porous plate body (7), such as a metal net, is placed in close contact with the outer circumference of the burner head (3). Vaporization cylinder (1) which vaporizes liquid fuel and mixes this vaporization gas with combustion air, and produces | generates a mixed gas, and many mixed gas which formed in this vaporization cylinder (1) in three or more stages up and down The burner head 3 which blows out and combusts from a flame hole is provided, The burner head 3 is a double structure inside and outside, A micro permeation hole is formed in the upper part of the circumferential wall of the inner 1st burner head 3b. In the lower part, a permeation hole is formed which is slightly larger than the micro permeation hole, and in the outer second burner head 3a, the permeation is slightly larger than the respective micro permeation holes of the inner first burner head 3b. The holes are disposed so as to face the micro-permeable holes of the first burner head 3b, respectively, to form flame holes, and a metal mesh 7 or the like on the outer circumference of the second burner head 3a. Combustion apparatus which is installed in close contact with the porous plate body. 2. The combustion apparatus according to claim 1, wherein the flame holes of the burner head (3) are gradually enlarged from the flame hole at the top toward the flame hole at the bottom so that the flame hole diameter at the bottom is largest. The gas cylinder cover 8 is disposed between the vaporization cylinder 1 and the burner head 3, and a mixed gas inlet 8a drawn in a small diameter is formed in the center of the vaporization cylinder lid. One combustor. The vaporization cylinder cover (8) according to claim 1, wherein a vaporization cylinder cover (8) having a mixed gas inlet (8a) drawn in a small diameter at its center is disposed between the vaporization cylinder (1) and the burner head (3). A combustion apparatus in which a resistance plate (9) having a plurality of small holes is provided in a portion facing the mixed gas of the cover.