JP4237563B2 - Rotating cup type oil burner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary cup type oil burner, and in particular, in a burner that atomizes and burns oil in a rotary cup, reduces contamination due to oil droplets or soot accumulation on the swirling blade part, and cleans the swirling blade. The present invention relates to a rotary cup type oil burner that minimizes the labor required.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, a rotary cup type oil burner used for boilers, incinerator auxiliary combustion, etc. uses a rotating blade on the outer periphery of the primary air for flame holding. Many are used. The flame holding by the swirling blade has an advantage that a strong flame holding force can be obtained because a strong reverse flow region is generated.
In the flame holder using the swirling blade, the pressure as shown in FIG. 3 (A), FIG. 3 (B), FIG. 3 (C), or FIG. A distribution is formed in the vicinity of the swirl vanes.
In FIG. 4, the same parts as those of the present invention shown in FIGS.
[0003]
[Problems to be solved by the invention]
In the conventional rotary cup type oil burner, as shown in FIG. 3 (A), if the negative pressure in the vicinity of the turning blade increases, the flame holding power increases, the flame is stabilized, and the combustion is continued. However, because of the strong negative pressure formed in the vicinity of the swirling blades, that is, when the backflow is too strong, the atomized oil droplets get on the backflow of the air and mainly on the swirling blade surface. There is a tendency to adhere to the furnace inner surface of the blades and carbonize (accumulate) as soot, especially in the rotating cup type oil burner that mainly burns heavy oil. If soot accumulates, the opening area of the swirl vane changes (decreases), and the combustion becomes unstable, leading to a shortage of combustion air.
In addition, soot deposits tend to accumulate in a series when the amount of soot deposit exceeds a certain level.
Therefore, in order to maintain the predetermined performance, there has been a problem that it is necessary to periodically clean the turning blade portion (stabilizer) in a relatively short time.
[0004]
In view of the above-described problems of the conventional rotary cup type oil burner, the present invention reduces the dirt caused by the accumulation of oil droplets or soot on the swirling blade part of the rotating cup type oil burner, and the effort required for cleaning the swirling blade. An object of the present invention is to provide a rotary cup type oil burner that can minimize the above.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the rotary cup type oil burner of the present invention is configured such that the primary air from the periphery of the rotary cup for oil atomization arranged at the shaft center, the secondary air from the outer periphery, and the swirl vanes from the outer periphery. In the rotary cup type oil burner configured so that the tertiary air is supplied to the outermost peripheral portion through the secondary air, the secondary air and tertiary air ejection speeds are slower than the quaternary air ejection speed. Thus, it is configured to be adjustable.
[0006]
The rotary cup type oil burner of the present invention is configured so that the ejection speed of the secondary air and the tertiary air can be adjusted to be slower than the ejection speed of the quaternary air. A stable flame holding function by the swirling blade is ensured in the range, and contamination of the surface of the swirling blade by oil droplets and soot can be prevented.
[0007]
In this case, the secondary air ejection speed can be adjusted to be slower than the tertiary air ejection speed by the secondary air throttle plate.
[0008]
As a result, the secondary air ejection speed can be easily adjusted with the secondary air throttle plate so that the ejection speed of the secondary air is slower than the ejection speed of the tertiary air. It can be maintained without losing the negative pressure region, and the flame holding power can be secured.
[0009]
In this case, the primary air and the tertiary air can be configured to have the same turning direction.
[0010]
Thereby, by making the swirl directions of the primary air and the tertiary air become the same direction, the flame holding power is enhanced, and good mixing of atomized mist droplets and combustion air is obtained, and the flame The length is short and low air ratio operation is possible.
[0011]
In this case, the quaternary air can be ejected in a direction intersecting on the axis.
[0012]
As a result, the quaternary air is ejected so as to intersect on the axis near the burner, so that the oil droplets just generated at the tip of the burner can collide and mix with the quaternary air relatively close to each other, Complete combustion is possible at a low air ratio.
[0013]
In this case, a plurality of swirling air distribution plates can be attached to the inside of the inner cylinder to which secondary and tertiary air is supplied in a direction perpendicular to the circumference.
[0014]
Thereby, the amount of air ejection from each part of the swirling air distribution plate can be made uniform and optimized, soot accumulation can be completely prevented, and a stable flame holding force can be secured.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a rotary cup type oil burner according to the present invention will be described below with reference to the drawings.
In general, in an oil burner, air is supplied in the flow direction from the center, and a turning force is applied by a turning blade (stabilizer), so that the pressure distribution in the burner stabilizer is as shown in FIG. 3 (conceptual diagram). become.
By the way, when the turning force by the turning blade (stabilizer) is strong, as shown in FIG. 3A, a strong negative pressure region is formed in the vicinity of the turning blade center portion. If this negative pressure region is too strong, the flame holding power is strong and the flame is stabilized, but on the other hand, the flow of oil droplets returns to the back side of the swirl vane, causing the swirl vane to become dirty with oil and adhere to soot It will be a thing.
On the other hand, when the turning force is weak, as shown in FIG. 3B, the backflow region is small and the flame holding force is weak, so that the flame is not stable and a misfire phenomenon is caused.
Further, when the amount of air from the center is large, as shown in FIG. 3 (D), the air at the center eliminates the negative pressure region near the center of the turning blade and the flame holding power decreases, so that ignition does not occur. Even then, it will quickly misfire.
On the other hand, according to the present invention, as shown in FIG. 3 (C), an appropriate swirl force is formed by the swirling blades so as to ensure flame holding and prevent the swirl blades from becoming dirty. It is a thing.
[0016]
1 and 2, reference numeral 1 denotes an oil atomizing rotary cup 1 disposed on an axial center. The rotary cup 1 is a hollow cup disposed through a burner housing 12 so as to rotate. At the center of the end of the hollow conical primary air nozzle 9 attached to the tip of the mounting shaft 11 and attached to the tip of the burner housing 12, the tip of the rotary cup 1 and the primary air nozzle 9 are arranged. Are arranged so that their tips are substantially the same position (coincidence position).
The fuel is supplied to the rotary cup 1 at the tip through a fuel oil passage 8 formed in the hollow mounting shaft 11. Further, the primary air I is introduced from a primary air intake port 19 opened at the rear end portion of the burner housing 12, and from the gap between the inner peripheral surface of the primary air nozzle 9 and the outer peripheral portion of the rotary cup 1, It is supplied to the vicinity of the front end of the rotating cup 1.
[0017]
The inner cylinder 3 is disposed at the front end portion of the burner casing 12 so as to surround the outer peripheral portion of the primary air nozzle 9. A gap is formed between the rear end of the inner cylinder 3 and the front end surface of the burner casing 12, and this gap serves as an inlet 10 for secondary and tertiary air. The air amount adjusting plate 4 is movably disposed. Although this is not particularly limited, for example, the amount of secondary and tertiary air introduced into the inner cylinder 3 by moving the air amount adjusting plate 4 by an operation such as a slide, that is, secondary, The total amount of tertiary air can be adjusted so that the total amount of secondary and tertiary air introduced into the inner cylinder 3 becomes appropriate.
[0018]
Further, the front end surface of the inner cylinder 3 is opened so that the front end side is slightly narrowed, and a tertiary air swirl vane 6 is disposed inside the inner cylinder 3, whereby the inner cylinder 3 is arranged from the front end surface of the inner cylinder 3. A desired swirling flow is given to the tertiary air III discharged into the cylindrical burner tile 15 attached to the tip of the cylinder.
A plurality of swirling air distribution plates 16 mounted in the inner cylinder 3 and in a direction perpendicular to the circumference thereof so that the tertiary air III is uniformly discharged from the front end opening of the inner cylinder 3, and the inner cylinder 3 is provided with a tertiary air swirling blade 6.
Part of the air introduced into the inner cylinder 3 in this way is from the secondary air supply port in the gap formed between the outer peripheral surface of the primary air nozzle 9 and the tertiary air swirling blade 6. The secondary air II is discharged into the burner tile 15 through the tip of the rotating cup 1. In this case, the discharge amount of the secondary air II is adjusted by the secondary air throttle plate 20 disposed in the primary air nozzle 9.
[0019]
Further, in the burner housing 12, a primary air fan 14 is attached to the outer peripheral portion of the rotating mounting shaft 11, and the rotating shaft 1 is rotated through the primary air nozzle 9 by rotating the mounting shaft 11. In this case, the primary air swirling blades 2 are disposed inside the tip of the primary air nozzle 9 so that the primary air I is swirled and supplied.
[0020]
A wind box 5 is disposed at the front end of the burner casing 12 so as to surround the outer peripheral portion of the inner cylinder 3 so as to be integrated with the burner casing 12 and is combusted so as to be tangential to the wind box 5. An air introduction pipe 7 is connected so that a swirl flow is given to the air introduced into the wind box 5, and secondary and tertiary air inlets 10 and quaternary air IV inlets from the wind box 5. 18 to be introduced separately.
The inlet 18 of the quaternary air IV is formed in a ring shape on the outer peripheral portion of the inner cylinder 3, and a rectifying plate 17 is disposed so that air can be supplied to the ring-shaped inlet 18 so as to have a uniform flow. To do. As a result, the quaternary air IV is ejected in a direction intersecting on the axis in the burner tile 15.
Further, a pilot burner 13 is disposed at the outer peripheral portion position of the inner cylinder 3 so as to be in the burner tile 15.
[0021]
Next, the operation of the rotary cup type oil burner of the present invention will be described.
Fuel is supplied from the fuel oil introduction pipe 8 to the oil atomizing rotary cup 1 arranged at the center of the burner, and the primary air I for combustion is attached coaxially to the rotary cup 1 and rotates together. The primary air fan 14 is supplied from the outer periphery of the rotary cup 1. In this case, the primary air I is slightly swirled by the primary air swirling blade 2 attached inside the tip of the primary air nozzle.
The swirling direction of the primary air is the same as that of the tertiary air and the rotating cup 1, thereby increasing the flame holding power and obtaining good mixing of atomized mist droplets and combustion air. In addition, the flame length is short and low air ratio operation is possible.
[0022]
The swirl angle of the primary air is set to a range of 10 to 30 degrees with respect to the axis, and the amount of the primary air I is set to about 10% to 20% of the whole air. However, if the amount is too large, the mixing of the oil droplets and the combustion air is lowered, the flame length is extended, and good combustion cannot be obtained.
[0023]
Further, it is important that the fuel atomized (atomized) and discharged from the tip of the rotating cup 1 is uniformly supplied to the inner surface of the rotating cup 1 in the circumferential direction. For this reason, the fuel oil supplied to the rotating cup 1 is formed into a thin film shape by the rotational force of the rotating cup 1 (for example, 5,000 rpm to 7,000 rpm), and the wind pressure of the primary air I to be supplied. It is blown off and promotes atomization. In this case, the ejection speed of the primary air I is set to be the fastest in order to promote atomization of the oil droplets in the primary air I to the quaternary air IV. The negative pressure portion near the center of the air swirling blade 6 is suppressed to a value that can be maintained. Therefore, in this invention, the primary air fan 14 is provided in the burner axial center part separately from the fan for combustion (not shown).
[0024]
Further, the secondary, tertiary and quaternary combustion air II, III and IV are tangent into the wind box 5 from a separate combustion blower fan (not shown) via the combustion air introduction pipe 7. It is introduced so as to turn by being guided in the direction.
The air introduced into the wind box 5 is swirled in the air, and a part of the air is rectified into a straight flow by the rectifying plate 17 in a direction intersecting on the axis near the burner from the inlet 18 of the fourth air IV. The remaining air is introduced into the inner cylinder 3 through the secondary and tertiary air inlets 10.
In this case, since the secondary and tertiary air is throttled by the air amount adjustment plate 4, the ejection speed of the secondary and tertiary air is set slower than the ejection speed of the quaternary air. Next, the air introduced into the inner cylinder is ejected as the tertiary air III while swirling through the swirling blades, and the remaining air is restricted in the passage amount by the secondary air throttle plate 20 and ejected as the secondary air II. Is done.
[0025]
If too much secondary air II is supplied from the outer periphery of the primary air I, as shown in FIG. 3 (D), the negative pressure of the negative pressure portion in the center portion decreases, resulting in a decrease in flame holding power. Then, it becomes unstable, and the flame jumps up and then misfires.
Therefore, the air velocity of the secondary air II ejected from this portion is set to be slower than the ejection velocity of the tertiary air III, and the oil droplets flow back into the gap between the primary air I and the secondary air II in terms of quantity. Do not supply an amount that does not. For this reason, the secondary air throttle plate 20 is set to 5% to 15% of the total combustion air. As a result, contamination of the gap can be prevented, and at the same time, the negative pressure region near the center can be maintained and flame holding power can be secured.
[0026]
Further, the tertiary air III is supplied from the outer peripheral portion of the secondary air II through the tertiary air swirling blade 6, and the jetting speed is adjusted by the air amount adjusting plate 4.
In this way, the ejection speed of the tertiary air III is set to be faster than the ejection speed of the secondary air II. In this case, the ejection amount of the secondary air II with the slowest ejection speed is such that the minimum amount of air that can prevent oil droplets from flowing back to the outer surface of the primary air nozzle 9 is supplied. If there is too much air, the negative pressure in the negative pressure portion will decrease, and the flame holding power will be lowered and become unstable.
Thus, by effectively setting the air ejection speed of each part, it is possible to secure the flame holding force and prevent the surface of the swirling blades and the primary air nozzle 9 from being contaminated by the soot.
[0027]
In addition, the quaternary air IV installed at the outermost peripheral part is ejected so as to intersect on the burner vicinity axis, so that the oil droplets just generated at the burner tip are relatively close to the quaternary air IV. They can collide and mix, and complete combustion is possible at a low air ratio.
[0028]
In this case, since the pilot burner 13 is inserted into the inner cylinder 3, an air velocity distribution is formed in the circumferential direction, that is, a uniform velocity distribution is not ensured.
Thus, when the velocity distribution is formed, a large negative pressure is generated in the portion where the air ejection speed is high (the portion where the turning force is strong), and the surface of the inside of the furnace of the turning blade (the wake portion of the burner) is generated. Dirt is generated.
For this reason, by attaching about 1 to 3 swirling air distribution plates 16 in the direction orthogonal to the swirl direction, that is, the axial direction (radial direction), to the inside of the inner cylinder 3, air jets from the respective portions of the swirling blades The amount is made uniform and optimized to eliminate the velocity distribution in the circumferential portion of the inner cylinder 3, an appropriate uniform negative pressure region is formed, and soot accumulates on the surfaces of the swirling blades and the primary air nozzle 18. It prevents contamination and ensures a stable flame holding power.
[0029]
The rotary cup type oil burner according to the present invention has been described based on the embodiments thereof. However, the present invention is not limited to the configurations described in the above embodiments, and the configurations thereof are appropriately made without departing from the spirit of the present invention. Can be changed.
[0030]
【The invention's effect】
According to the rotary cup type oil burner of the present invention, since the secondary air and tertiary air ejection speed is adjustable so as to be slower than the quaternary air ejection speed, the load is reduced from a high load to a low load. A stable flame holding function by the swirling blade is ensured in a high range, and contamination of the swirling blade surface by oil droplets and soot can be prevented.
[0031]
In addition, the secondary air ejection plate can be easily adjusted with the secondary air throttle plate so that the secondary air ejection speed is slower than the tertiary air ejection speed. It can be maintained without losing the pressure range, and the flame holding power can be secured.
[0032]
In addition, by making the swirl directions of the primary air and the tertiary air the same direction, the flame holding power is enhanced, and good mixing of atomized mist droplets and combustion air is obtained, and the flame length And can be operated at a low air ratio.
[0033]
Also, by ejecting quaternary air so as to intersect on the burner vicinity axis, oil droplets just generated at the tip of the burner can collide and mix with the quaternary air relatively close to the low air Complete combustion can be made possible by the ratio.
[0034]
In addition, since a plurality of swirling air distribution plates are attached to the inside of the inner cylinder to which secondary and tertiary air are supplied in a direction orthogonal to the circumference, the amount of air jetted from each part of the swirling air distribution plate is made uniform and It can be optimized, soot accumulation can be completely prevented, and a stable flame holding power can be secured.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing an embodiment of a rotating cup type oil burner of the present invention.
2 is a longitudinal sectional front view taken along line AA in FIG.
FIGS. 3A and 3B are pressure distribution diagrams of a burner stabilizer, where FIG. 3A is a case where the turning force is strong, FIG. 3B is a case where the turning force is weak, and FIG. Indicates the respective pressure distributions when the amount of air from the center is large.
FIG. 4 is a cross-sectional view showing a conventional burner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating cup 2 Primary air swirling blade 3 Inner cylinder 4 Air amount adjusting plate 5 Wind box 6 Tertiary air swirling blade 7 Combustion air introduction pipe 8 Fuel oil passage 9 Primary air nozzle 10 Secondary air Inlet 11 Mounting shaft 12 Burner housing 13 Pilot burner 14 Primary air fan 15 Burner tile 16 Swirling air distribution plate 17 Rectifying plate 18 Secondary air inlet 19 Primary air inlet 20 Secondary air throttle plate I Primary air
II Secondary air
III Tertiary air
IV Fourth air

Claims (5)

Primary air is supplied from the periphery of the oil atomizing rotary cup disposed at the shaft center, secondary air is supplied from the outer periphery thereof, tertiary air is supplied from the outer periphery through the swirling blades, and quaternary air is supplied to the outermost peripheral portion. In the rotary cup type oil burner configured as described above, the rotary cup type oil is configured such that the ejection speed of the secondary air and the tertiary air can be adjusted to be slower than the ejection speed of the quaternary air. Burner. 2. The rotary cup type oil burner according to claim 1, wherein the secondary air ejection speed can be adjusted to be slower than the tertiary air ejection speed by the secondary air throttle plate. The rotary cup type oil burner according to claim 1 or 2, wherein the swirl directions of the primary air and the tertiary air are the same. The rotary cup type oil burner according to claim 1, 2 or 3, wherein the quaternary air is jetted in a direction intersecting on the axis. 4. A rotating cup type oil burner according to claim 1, wherein a plurality of swirling air distribution plates are attached to the inside of the inner cylinder to which secondary and tertiary air is supplied in a direction orthogonal to the circumference. .

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