JP2015025634A - Oil burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil burner capable of making even fuel with high viscosity into fine grains without requiring collision of atomization of two atomizers in order to obtain atomization of fine grains.SOLUTION: A wall surface is provided ahead of an atomizer, and atomization from the atomizer is made collide with the wall surface to form secondary atomization of fine grains. A revolved combustion air is supplied to the secondary atomization, to generate flame ahead of the wall surface. Stable flame is obtained by covering a combustion chamber containing the flame with a fire-proof wall. In a case of fuel with high viscosity, the fuel and the wall surface are heated to reduce the diameter of an atomization grain. Flame as well as electric heat is used for heating the wall surface.

Description

  The present invention relates to an oil burner that improves the drawbacks of impinging atomizers.

  First, an oil burner using a conventional collision sprayer will be described. FIG. 3 shows a cross-sectional view of an oil burner using a conventional impinging sprayer, and FIG. 4 shows a cross-sectional view seen from the front thereof. In these drawings, sprays 12 and 13 jetted obliquely from two sprayers 10 and 11 collide with each other on a horizontal plane including the axis of the burner. As a result, the spray 14 is further reduced in particle size and flows to the left side of the figure (hereinafter referred to as the front). The surrounding combustion air swirl creates a negative pressure at the burner axis, and the spray 14 is sucked and collected in the center. When the mixture of the spray 14 and the combustion air is ignited, a small flame 16 is generated.

  At this time, in order to obtain a good spray with the two sprayers 10 and 11, the centers of the two sprays 12 and 13 must be exactly coincident. However, in a burner in which the sprayers 10 and 11 are exposed to a high temperature during operation, it is difficult because the sprayers 10 and 11 are deformed by heat and the sprays 12 and 13 are warped. A structure that does not impair the spray performance even when the sprayers 10 and 11 are deformed is required.

  It is difficult to burn high-viscosity oil with an oil burner using a conventional impingement sprayer because the sprays 12 and 13 are combined.

Atomization characteristics of collision type atomizer Kiyoshi Ohara The Japan Institute of Energy 1999 p.75-79

In order to obtain the sprays 12 and 13 having a small particle size by the two sprayers 10 and 11, both the sprays 12 and 13 must be symmetrical with respect to the collision surface, and the orientation, the spray shape, and the like must be completely matched. This is very difficult especially when the nebulizers 10 and 11 are subjected to deformation due to heat.

  An object of the present invention is to provide an oil burner using a wall collision sprayer in which the angles and distributions of both sprays 12 and 13 may be slightly different due to thermal deformation.

  Also, when handling high-viscosity liquids in collision spray, an oil burner using a collision sprayer that does not have such a phenomenon that the particle size becomes large due to adhesion and coalescence when sprays collide with each other. With the goal.

The present invention is an oil burner that includes a sprayer that sprays fuel, a wall surface that a spray disposed in front of the tip of the sprayer collides, and a fire wall that houses the sprayer and the wall surface.

  According to the present invention, since the secondary spray that scatters radially by colliding the spray with the wall surface is formed, the performance of the secondary spray is not affected even if the center of the spray is slightly deviated.

Sectional drawing of one Example of the oil burner which concerns on this invention. The front view of the said one Example. Sectional drawing of the oil burner using the conventional collision sprayer. The front view of the said oil burner.

  FIG. 1 shows a cross-sectional view of an oil burner using the wall sprayer of the present invention, and FIG. 2 shows a cross-sectional view seen from the front thereof. Here, one sprayer 1 for spraying fuel is disposed on the axis of the burner, and a wall surface 3 is provided in a predetermined position in front of the tip of the sprayer 1. Then, even if the center of the spray 2 is slightly out of order, the spray performance does not change so much because the wall surface 3 is a wall surface having a large area.

  If the spray particle size becomes large when high-viscosity sprays collide with each other or collide with the wall surface 3, it can be prevented by lowering the viscosity of the spray 2. For this purpose, a high-viscosity spray may be heated and heated.

  Further, when the wall surface 3 is heated to a high temperature, when the spray 2 collides with the wall surface 3, the temperature of the spray 2 rises and the viscosity decreases, so that the spray particle size does not increase due to coalescence. If the wall surface 3 is very hot, the spray 2 is heated to evaporate and atomize.

  The shape of the wall surface 3 may be various, such as a circular or polygonal plane, a cone, or a curved surface. The size of the secondary spray 4 can be changed, and the wall 3 can be made polygonal, or if the notch is provided, the secondary spray 4 scattered from the wall 3 can be made non-uniform (light and shade). Can do.

  In order to use the sprayer 1 for a boiler oil burner, it is necessary to collect the secondary spray 4 scattered from the wall surface 3 at the center of the burner to form a flame 6 having an appropriate shape. For this reason, as shown in FIGS. 1 and 2, air is sent from the two blower pipes 5 in the tangential direction from around the axis of the burner, and the secondary spray 4 scattered from the wall surface 3 is indicated by arrows from the periphery of the wall surface 3. As shown, the combustion air is supplied while swirling.

  Due to the swirling of the air, a negative pressure is generated on the axial center of the burner ahead of the wall surface 3, the secondary spray 4 is sucked into this, and the combustion air and the secondary spray 4 from the two blower pipes 5 are mixed, When this is ignited, a flame 6 having a collective shape is generated.

  A cover 8 is provided at the tip of the sprayer 1 so that the spray 2 emitted from the sprayer 1 is not disturbed by the swirling combustion air.

  If the combustion air is supplied in the tangential direction from around the sprayer 1 as shown in FIG. 2, the flame 6 can be formed in front of the wall surface 3, so that the sprayer 1 is not directly heated by the flame 6 and no deformation occurs. .

  If the wall surface 3 has a polygonal shape or a star shape and is provided with cuts or the like, the combustion air is supplied non-uniformly to the uniformly distributed secondary spray 4, so that an oxygen concentration / divided flame is formed. , Low NOx combustion.

  If the flame 6 is covered with a cylindrical fire wall 7 as shown in FIG. 1, the secondary spray 4 and the combustion air cannot escape outward, so that the air ratio is low because it approaches the center flame 6. Even combustion will be better.

  When the viscosity of the fuel is high, since the adhesive force is large, the particle size of the spray increases due to the coalescence of both the collision spray and the wall collision spray. Since the viscosity of the oil decreases as the temperature is increased, if the oil is heated, the particle size does not increase and the particle size becomes smaller.

  In order to heat the wall surface 3, there are a method using electric heat and a method using flame. The former is easy to control the temperature of the wall surface 3. In the latter case, the flame 6 is in contact with or close to the wall surface 3, so that the wall surface 3 is heated.

  According to the present invention, since the secondary spray 4 is formed in which the spray 2 collides with the wall surface 3 and scatters radially, even if the center of the spray 2 is slightly deviated, the performance of the secondary spray 4 is not affected.

  In the case of the conventional collision spray, since the spread of the spray is large, it is difficult to properly supply the combustion air, and the spray is disturbed if the swirl of the combustion air is increased to reduce the flame. On the other hand, in the case of the wall surface collision spray according to the present invention, when the wall surface is, for example, a disk and the combustion air is swirled and supplied from therearound, a negative pressure is generated on the axis of the burner, resulting in a secondary spray. And a flame is drawn to form a short flame.

  Depending on the shape and notch around the wall surface, the manner in which the combustion air swirls changes, and low NOx combustion can be performed.

  The spray particle size becomes small when sprayed from a small-diameter nozzle, and therefore a plurality of nozzles are used when the amount of oil is large.

  The secondary spray sprayed around is collected on the axis of the burner, and the flame is covered with a cylindrical fireproof wall in order to supply combustion air so as not to diffuse around. Then, since the secondary spray and the combustion air cannot escape outward, a low air ratio combustion is obtained by approaching the center flame.

High-viscosity oils adhere and coalesce at low temperatures when the spray collides, so the spray particle size increases. However, if the oil is heated to a high temperature, this phenomenon disappears and the particle size decreases. An oil heater is installed to make the oil hot. Heating the wall surface is also effective. To heat the wall surface, heat it with electric heat or flame.
1 and 2 show the structure of an embodiment of the present invention. FIG. 1 is a transverse sectional view thereof, and FIG. 2 is a sectional view seen from the front thereof. Oil or the like is sprayed from the sprayer 1 using hydraulic pressure, air, steam, or the like, becomes spray 2 and collides with the wall surface 3, thereby further becomes fine particles and becomes secondary spray 4 along the surface of the wall surface 3. Scattered. As shown in FIGS. 1 and 2, the combustion air is supplied from the blower pipe 5 to the base of the sprayer 1 in a tangential direction and swirls, and the hollow air is formed by the fire wall 7 beyond the outer periphery of the wall surface 3. Enters the combustion chamber, swirls in front of the wall surface 3 to create a negative pressure, and sucks the secondary spray 4. When this mixture of spraying and combustion air is ignited, a compact flame 6 can be formed. Since the diameter of the combustion chamber is small at the left end of the figure, the combustion air cannot spread outward when flowing forward, so that it closely adheres to the flame 6 and the combustion is strengthened.
Since the spray 2 may be disturbed by the swirling of combustion air, a frustoconical cover 8 is provided at the tip of the sprayer 1 to prevent this.

  When the load (oil amount) is reduced, the amount of combustion air is also reduced, so that the turning force is also weakened and the flame 6 is also poorly packed. In order to prevent this, the sprayer 1, the wall surface 3, and the cover 8 are integrally moved on the axis of the burner as indicated by an arrow 9. As a result, the gap between the wall surface 3 and the refractory wall 7 is reduced, and the turning force of the combustion air is maintained. The wall surface 3 is supported from the cover 8 by a round bar (post) not shown.

  In the oil burner provided with the sprayer 1 of FIG. 1, the combustion air supplied in the tangential direction from the two blower pipes 5 arranged eccentrically upstream of the sprayer 1 swirls strongly, and this collides with the wall surface 3. When the secondary spray 4 hits the secondary spray 4 that is sprayed and scatters radially from the wall surface, the combustion air swirling as shown by the arrow is drawn by the negative pressure created in the axis of the burner and gathers in the center. Burn. The axial flame 6 is lumped and burned violently by the swirling of combustion air. A cylindrical fireproof wall 7 is provided around the flame 6 to prevent the secondary spray 4 and combustion air from escaping outward.

  There are strong demands for short flame, complete combustion, low air ratio, and low NOx in oil burners. In order to solve this problem, atomization of the spray particle size is extremely effective. Since atomization makes rapid combustion possible, short flame and complete / low air ratio combustion are achieved, and it is easy to take measures to reduce NOx. The conventional impinging spray is an effective means of atomization, but the centers of the two sprays need to coincide. On the other hand, in the wall surface collision spray according to the present invention, the center of the spray 2 may be shifted.

  When the load is low, the amount of combustion air is reduced, and the turning force is reduced, whereby the centripetal force of the flame 6 is reduced. In order to prevent this, the swirl force of the combustion air is supplemented by a mechanism for reducing the gap between the wall surface 3 and the fire wall 7 or by installing swirl vanes.

  If the wall surface 3 is made polygonal or star-shaped or cut, the flow of combustion air becomes non-uniform, resulting in low-NOx combustion resulting in light and dark combustion or a split flame. When a plurality of small-capacity burners are arranged, the spray becomes finer, and by changing the amount of combustion and the amount of air for each burner, light and dark combustion and two-stage combustion can be obtained, and low NOx can be achieved.

In the embodiment of FIG. 1, the wall surface 3 is a plane, but it can also be conical or curved. In this case, it arrange | positions so that a convex surface may face the spray 2. FIG. Thereby, the spray 2 collides with the convex surface of the conical surface or the curved surface, the reflection angle of the spray particles on the concentric circle of the spray 2 slightly changes, and the secondary spray 4 has a special spatial distribution. . This changes the shape of the flame and has a beneficial effect on fuel combustion characteristics and low NOx.
A high-viscosity fuel has a smaller particle size because either one or both of the fuel and the wall surface 3 are heated, and the viscosity of the spray is reduced to prevent sticking and coalescence. Electric heat or the like is used for heating the fuel, and flame 6 is used for heating the wall surface 3 in addition to electric heat or the like.

  Since the swirl force is weakened when the flow rate of combustion air decreases due to a low load (low oil amount), the sprayer 1, the cover 8, and the wall surface 3 of FIG. When moved, the gap between the wall surface 3 and the refractory wall 7 is reduced, so that the flow velocity of the combustion air is increased and the turning force is maintained. If the turning force is not sufficient only by this, a turning blade (not shown) is provided at an appropriate position such as the gap to keep the turning force.

  One in which a plurality of burners of FIG. 1 are arranged side by side is considered as another embodiment. In this case, although not shown, the burner of FIG. 1 is arranged in parallel with a suitable space on the front wall of the boiler.

DESCRIPTION OF SYMBOLS 1 Sprayer 2 Spray 3 Wall surface 4 Secondary spray 5 Blow pipe 6 Flame 7 Fireproof wall 8 Cover 9 Sliding mechanism 10 Sprayer 11 Sprayer 12 Spray 13 Spray 14 Spray 15 Blower pipe 16 Flame

Claims (5)

  An oil burner comprising: a sprayer that sprays fuel; a wall faced by the spray disposed in front of a tip portion of the sprayer; and a fire wall that houses the sprayer and the wall surface.   The oil burner according to claim 1, wherein when the spray collides with the wall surface, the spray is further atomized to form a secondary spray.   The oil burner according to claim 1 or 2, wherein a flame is swirled by supplying air while swirling the secondary spray atomized by the wall surface, thereby sucking the flame to a negative pressure generated at the axis of the burner.   The oil burner according to any one of claims 1 to 3, wherein the wall surface is a polygonal shape or a star shape, or is a flat surface, a conical body, or a curved surface body provided with a notch.   The oil burner as described in any one of Claims 1-4 which attaches the apparatus which heats both high-viscosity oil and the said wall surface, or one side.

Images