TWI712761B - Solid fuel burner - Google Patents

Abstract

[Problem] The present invention provides a solid fuel burner that can ensure the ignitability and flame maintenance of the fuel nozzle. Furthermore, the present invention provides a solid fuel burner, for example, simplifying the structure of the fuel nozzle, achieving cost reduction, and ensuring the ignitability or flame maintenance of the fuel nozzle. In addition, a burner is provided, which can stably burn solid fuel or oil combustion for the purpose of suppressing the occurrence of coal dust or smoke during oil start. [Solution] The solid fuel burner of the present invention has: a straight pipe portion of the fuel nozzle for the mixed gas of the solid fuel and its conveying gas to circulate; and the constriction portion of the fuel nozzle that divides the mixed gas flowing through the straight pipe portion of the fuel nozzle. The flow path is constricted; the fuel nozzle expansion part expands the flow path of the mixed gas flowing through the fuel nozzle constriction part to the horizontal direction; the fuel nozzle outlet part is connected with the fuel nozzle expansion part, and the outlet has a flat shape; The outer peripheral flame holder is arranged in the outer peripheral direction of the fuel nozzle outlet part, and the internal flame holder is arranged at the fuel nozzle outlet part, and divides the mixed gas flowing through the fuel nozzle enlarged part in the horizontal direction.

Description

Solid fuel burner

The present invention relates to a solid fuel burner.

As a prior art in this technical field, there is Japanese Patent Laid-Open No. 10-220707 (Patent Document 1). The publication states that an external flame-maintaining ring is installed on the outer circumference of the burner, and an internal flame-maintainer is installed inside the pulverized coal supply pipe. The internal flame-maintainer is installed to direct high-temperature gas from the outer circumference of the burner The flame maintenance plate towed by the center of the burner. In addition, a distributor is installed on the front flow side of the burner of the internal flame retainer to increase the flow of pulverized coal in the center of the burner and reduce the pulverized coal to the outer periphery of the burner. flow.

In addition, as a prior art in this technical field, there is JP 2014-055759 A (Patent Document 2). The publication describes a combustion device that includes a venturi and a concentrator with a constriction in the fuel flow path. The cross section is circular until the constriction near the constriction, and then the cross section gradually becomes flat in the left and right directions. The shape of the pulverized coal burner is arranged on at least one surface of the furnace wall with multiple sections and multiple rows. The pulverized coal burner has the largest pulverized coal nozzle at the opening of the furnace wall. The width direction of the flat nozzle is appropriately arranged in the up and down, left and right directions. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-220707 [Patent Document 2] JP 2014-055759 A

[The problem to be solved by the invention]

In the aforementioned Patent Document 1, there is described a solid fuel burner having an internal flame holder and an external flame maintaining ring, and in the aforementioned Patent Document 2, a pulverized coal burner is described, which has a pulverized coal nozzle with a flat outlet . However, with the solid fuel burner described in Patent Document 1 or the pulverized coal burner described in Patent Document 2, when the burner increases in size, the ignition area for fuel injection will be relatively small, resulting in ignition, Possibility of flame maintenance instability.

Therefore, the present invention provides a solid fuel burner, even if the burner is increased in capacity or the non-flammable fuel with less volatile components, such as anthracite or oil coke, with high fuel ratio than solid fuel, or supply The average particle size of the solid fuel to the burner is relatively large, and compared with pulverized coal, the fuel that is difficult to burn in the boiler, such as biomass fuel, can also ensure the fuel nozzle when burning in a coal-fired boiler. Ignitability or flame maintenance. Moreover, the present invention provides a solid fuel burner, which simplifies the structure of the fuel nozzle, realizes cost reduction, and can reduce the environmental burden represented by low NOx and low CO, the unburned components in the ash, and the exhaust gas Efficient combustion such as CO reduction becomes possible. In addition, we provide solid fuel burners equipped with oil starting burners. The solid fuel burners and starting oil burners are coaxially constructed, which can reduce coal dust, oil smoke, and CO during use of the oil starting burners . [Means to solve the problem]

In order to solve the above-mentioned problems, the solid fuel burner of the present invention is characterized by having: a fuel nozzle straight pipe portion for circulating a mixed gas of solid fuel and its conveying gas; and a fuel nozzle constriction portion that passes the flow through the fuel nozzle straight pipe The flow path of the mixed gas in the fuel nozzle section is restricted; the expansion section of the fuel nozzle expands the flow path of the mixed gas flowing through the constriction section of the fuel nozzle to the horizontal direction; the outlet section of the fuel nozzle is connected with the expansion section of the fuel nozzle, and its outlet It has a flat shape; an annular outer flame holder is arranged in the outer circumferential direction of the fuel nozzle outlet part; and an internal flame holder is arranged at the fuel nozzle outlet part and divides the mixed gas flowing through the fuel nozzle enlarged part in the horizontal direction. [Effects of the invention]

According to the present invention, a solid fuel burner can be provided, and the ignitability or flame maintenance of the fuel nozzle can be ensured even in the future. Furthermore, according to the present invention, a solid fuel burner can be provided, the structure of the fuel nozzle can be simplified, the cost can be reduced, and the ignitability or flame maintenance of the fuel nozzle can be ensured.

The problems, structures, and effects other than the above are clarified from the description of the following embodiments.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same structure is given the same symbol, and the description of the overlapping part may be omitted. [Example 1]

In coal-fired boilers and other combustion devices that use solid fuels, in order to reduce harmful emissions such as nitrogen oxides (NOx) or improve combustion efficiency, the solid fuel burners used in combustion devices must be stable Ignition and flame maintenance. In order to achieve stable ignition and flame maintenance, a flame maintainer is installed in the fuel nozzle of the solid fuel burner. Here, it is important to supply a sufficiently high-concentration fuel stream (solid fuel particles). In particular, when the solid fuel burner becomes larger and a larger ignition area is required, or when the load of the solid fuel burner fluctuates and the low-load operation is performed, it is also necessary to have stable ignition and flame maintain.

FIG. 1A is an explanatory diagram showing a vertical center section of the solid fuel burner described in Example 1. FIG. 1B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the first embodiment.

The solid fuel burner described in this embodiment has: a fuel nozzle straight pipe part (hereinafter only referred to as "straight pipe part" for explanation) 4 for circulating a mixed gas 100 of solid fuel and its conveying gas; the fuel nozzle is constricted Section (hereinafter only referred to as the "restriction section" for explanation) 5, which restricts the flow path of the mixed gas 100 flowing through the straight pipe section 4 to accelerate the mixed gas 100; fuel nozzle expansion section (hereinafter only described as "Expansion part" for explanation) 6. Supply the mixed gas 100 accelerated by the constriction part 5 to circulate and decelerate, and expand the flow path of the mixed gas 100 in the horizontal direction; and the fuel nozzle outlet part (only described below To describe the "outlet portion") 16, it is connected to the expansion portion 6, and the mixed gas 100 flowing through the expansion portion 6 is ejected into the furnace.

The outlet portion of the outlet portion 16 has a flat shape whose width expands in the horizontal direction. In addition, the constriction-restricting portion 5 is of a venturi type that shrinks from the entire circumference.

Furthermore, the straight pipe portion 4, the constriction portion 5, the enlarged portion 6, and the outlet portion 16 constitute a fuel nozzle and form a flow path of the mixed gas 100.

In the outer circumferential direction of the fuel nozzle (the straight pipe portion 4, the constriction portion 5, and the enlarged portion 6), a wind box 10 that conducts combustion air is provided.

In addition, in the outer circumferential direction of the outlet portion 16, a guide sleeve 7 for blowing combustion air to the furnace is provided. On the outer side of the guide sleeve 7 in the up-down direction, an up-and-down guide sleeve 8 for spraying combustion air in the up-down direction of the furnace is provided. In addition, a furnace wall 9 is provided in the outer circumferential direction of each of the guide sleeve 7 in the left-right direction and the upper and lower guide sleeves 8 in the vertical direction.

In the outer circumferential direction of the outlet portion 16, an annular outer circumferential flame holder 2 is provided. In addition, the guide sleeve 7 is installed in the outer peripheral direction of the outer peripheral flame holder 2.

In addition, the outlet portion 16 is provided with an internal flame holder 1 having a wedge shape whose cross-sectional shape is an equilateral triangle. The internal flame holder 1 is provided at the center of the horizontal direction, and divides the mixed gas 100 flowing through the enlarged portion 6 in the horizontal direction.

A center rod 3 is provided in the center portion of the fuel nozzle (the straight pipe portion 4, the constriction portion 5, and the enlarged portion 6). In this embodiment, the center rod 3 is not provided with a particle concentrator that blows solid fuel particles (hereinafter only referred to as "particles") in the outer circumferential direction to concentrate.

The mixed gas 100 ejected from the outlet portion 16 to the furnace forms a fuel jet 104. In addition, the combustion air sprayed toward the furnace and diffused in the outer circumferential direction from the guide sleeve 7 and the upper and lower guide sleeves 8 forms a combustion air jet 101.

A circulating flow 102 is formed between the fuel jet 104 and the combustion air jet 101. The circulating flow 102 is formed behind the outer peripheral flame holder 2. In the circulating flow 102, the high-temperature combustion gas burned inside the furnace is retained, and the high-temperature combustion gas is brought into contact with the fuel jet 104, thereby immediately igniting particles behind the outer peripheral flame holder 2 to form flame.

In the solid fuel burner described in this embodiment, the outlet portion 16 has a flat shape that is short in the vertical direction (up and down direction) and long in the horizontal direction (left and right direction). Although the enlarged portion 6 is enlarged in the horizontal direction, it is not enlarged in the vertical direction. In other words, the connecting portion between the enlarged portion 6 and the outlet portion 16 also has a flat shape.

Generally speaking, the shape of the opening of the fuel nozzle of the solid fuel burner (the nozzle of the fuel jet to the furnace) is circular, and the outlet of the solid fuel burner is relatively vertical (up and down). In the case of a flat shape that is short and long in the horizontal direction (left-right direction), the area of the flow path of the combustion air ejected from the outer circumference of the outlet portion is wide in the vertical direction and narrow in the horizontal direction. Therefore, the flow rate of combustion air is higher in the vertical direction and lower in the horizontal direction.

In the solid fuel burner described in this embodiment, in order to guide the combustion air in the vertical direction with a large flow rate in the outer circumferential direction, only the upper and lower guide sleeves 8 are provided in the vertical direction. When the flow rate of the combustion air is large, the combustion air has a large amount of movement and is ejected from the inside of the furnace, so a large circulating flow 102 is formed behind the outer peripheral flame holder 2 in the vertical direction.

The larger the size of the circulating flow 102 is, the more high-temperature combustion gas can be retained. The mixing of the fuel jet 104 or the supply of radiant heat enables stable ignition and flame maintenance of the fixed fuel. Therefore, the fuel nozzle having a flat shape that is long in the horizontal direction at the outlet portion 16 can form a large circulating flow 102 up and down in the vertical direction, and stable ignition and flame maintenance can be achieved.

In the solid fuel burner described in this embodiment, the internal flame holder 1 is installed so that the flow path of the outlet portion 16 is divided in the horizontal direction. That is, the internal flame holder 1 divides the mixed gas 100 flowing through the enlarged portion 6 in the horizontal direction. The internal flame holder 1 provided to divide the flow path of the outlet portion 16 in the horizontal direction functions as a bridge connecting the upper and lower outer peripheral flame holders 2. On the upper and lower outer peripheral flame holders 2, due to the effect of a horizontally long flat fuel nozzle, a large circulating flow 102 is formed, so that high-temperature combustion gas is stably supplied to the external flame holder 2 Near.

By installing the internal flame holder 1 described in this embodiment, the high-temperature combustion gas of the larger circulating flow 102 can be drawn to the center behind the outlet portion 16, that is, it can form: The gas is drawn to the high-temperature gas flow 103 in the center behind the outlet portion 16. As described above, the high-temperature combustion gas is drawn to the center of the back of the outlet portion 16, whereby even a small circulating flow (not shown) behind the internal flame holder 1 flows from the inner side of the divided fuel injection 104 to Until ignition, stable ignition and flame maintenance of the entire fuel injection can be realized.

With the venturi-shaped constriction 5, the particles are concentrated toward the center of the fuel nozzle.

The internal flame holder 1 described in this embodiment is installed in the center of the horizontal direction, whereby the concentrated particles can be circulated to the vicinity of the internal flame holder 1. Furthermore, a fuel stream (particles) with a high concentration can be circulated to the vicinity of the internal flame holder 1, so that stable ignition and flame maintenance can be realized.

In addition, the internal flame holder 1 described in this embodiment has a wedge shape with a cross-sectional shape of an equilateral triangle, so that the fuel jet 104 is dispersed to spread in the horizontal direction, which can spread flames inside the furnace and suppress the inside of the furnace The localization of flames. This will cause the homogenization of the fuel inside the furnace, so it is effective in reducing NOx or unburned components.

In addition, in this embodiment, although one internal flame holder 1 is provided in the center in the horizontal direction, it is also possible to provide multiple internal flame holders 1 in the horizontal direction. In addition, the cross-sectional shape of the internal flame holder 1 is not limited to an equilateral triangle, and a pentagonal cross-section or a shape in which a depression is added to the furnace portion on the downstream side of the internal flame holder may be adopted.

Examples of these specific shapes are shown in FIGS. 7B to 7F. Basically, although it has the function of dividing the solid fuel in two directions, depending on the type of fuel or the particle size of the fuel, it is difficult to pull it to the circulatory area of the wake of the internal flame holder, making ignition difficult. In this case, if the above-mentioned recessed structure is provided, a wider circulation area can be formed, so stable ignition can be achieved. In addition, from the standpoint of production cost, compared with solid triangular posts, 7C-1 or 7C-2 with a V-shaped structure made of plates can achieve lower cost, so when sufficient ignition performance can be obtained , V-shaped internal flame holder is also an option.

(Function 1) Conventional solid fuel burners equipped with a peripheral flame holder have a particle concentrator installed on the center rod of the fuel nozzle. The particle concentrator is to blow the particles to the outer circumference to concentrate, so as to increase the fuel (particle) concentration around the flame holder at the periphery of the outlet of the fuel nozzle.

In other words, a fuel nozzle with a particle concentrator installed on the center rod constricts the fuel nozzle by the constriction of the fuel nozzle, blowing particles toward the center, colliding with the particle concentrator, and pushing the particles out. Blow and concentrate in the circumferential direction to increase the fuel (particle) concentration around the outer flame holder.

In order to increase the fuel (particle) concentration around the outer flame holder as described above, it is necessary to install a particle concentrator, which results in the increase of the supporting member of the particle concentrator at the front end of the solid fuel burner or the solid fuel burner The expansion of the shaft length has become the reason for the increase in cost.

Moreover, in the particle concentrator, because the high-concentration fuel stream (particles) collides at a speed of tens of meters per second, the amount of wear increases. Therefore, the material of the particle concentrator has to use high-grade materials with high hardness, which increases the cost. s reason.

In addition, in the particle concentrator, it is necessary to collide the particles with a larger collision angle, so the amount of wear will increase. Moreover, the particles blown in the outer circumferential direction by the particle concentrator will collide with the inner wall of the fuel nozzle and be concentrated, which increases the amount of wear on the inner wall of the fuel nozzle. Moreover, if the particle concentrator is installed on the center rod, the flow The cross-sectional area of the path will be reduced, so that the velocity of the particles of the fuel nozzle will increase, so the velocity of the particles that collide with the inner wall of the fuel nozzle will also increase, which will increase the amount of wear on the inner wall of the fuel nozzle. Therefore, it is necessary to use high-grade materials with high hardness for the material of the fuel nozzle, which is the reason for the increase in cost.

In particular, when a fuel nozzle is used and the outlet portion of the fuel nozzle has a flat shape in the horizontal direction, the particles blown out in the outer circumferential direction by the particle concentrator provided in the center rod of the fuel nozzle are discharged from the particle concentrator The moving distance to the outlet of the fuel nozzle is longer in the horizontal direction than in the vertical direction. Therefore, the particles cannot reach the horizontal direction sufficiently, and there is a possibility that the fuel (particle) concentration in the horizontal direction of the outer flame holder may decrease, and it is likely to cause a horizontal ignition failure. In order to avoid this problem, the use of a flat fuel nozzle requires an increase in the diameter of the particle concentrator or an increase in the shaft length of the solid fuel burner, which causes the increase in cost.

As mentioned above, in order to suppress the increase in cost, it is effective to delete the particle concentrator.

However, in the case of deleting the particle concentrator, the high-concentration fuel flow (particles) concentrated in the center of the constriction section 5 will be directly sprayed into the furnace, and will not form a circulating flow that is trapped by the high-temperature combustion gas. Since the external flame holder 2 of 102 circulates, the combustion performance (ignitability) is significantly reduced.

Here, the solid fuel burner described in this embodiment replaces the particle concentrator, and an internal flame holder 1 is provided at the outlet portion 16, so that the high-concentration fuel flow concentrated in the center direction in the constriction portion 5 (Particles) are ignited in the internal flame holder 1, so that the increase in cost can be suppressed without reducing the combustion performance (ignitability).

The solid fuel burner described in this embodiment uses an internal flame holder 1 installed at the outlet portion 16 to make a high-concentration fuel flow (particles) concentrated in the center of the constriction portion 5 to form The circulating flow 102 in which the high-temperature combustion gas stays circulates near the external flame holder 2 to improve the combustion performance (ignitability).

In other words, the solid fuel burner described in this embodiment does not provide the particle concentrator on the center rod 3, but effectively uses the high-concentration fuel stream (particles) concentrated in the constriction section 5 toward the center. ), which can improve combustion performance (ignitability).

In addition, the solid fuel burner described in this embodiment can also reduce the amount of wear on the inner wall of the fuel nozzle compared with the conventional solid fuel burner with a particle concentrator. The particle concentrator was deleted in order not to actively blow particles away from the outer periphery.

(Function 2) In addition, in combustion equipment, there is a strong demand for cost reduction of combustion equipment. One of the measures for cost reduction is to increase the capacity of solid fuel burners. By increasing the capacity, the number of solid fuel burners can be reduced, the number of pipes that circulate the mixed gas of solid fuel and conveying gas can be reduced, and the number of pulverizers for pulverizing solid fuel can be reduced. Cut costs.

However, with the increase in the capacity of solid fuel burners, the diameter of fuel nozzles used in solid fuel burners will expand, and the unfired area near the center of the fuel nozzle will expand, which may cause nitrogen oxides (NOx). ), etc., increase in harmful emissions or decrease in combustion efficiency.

In addition, with the reduction of the number of solid fuel burners, the distance between the solid fuel burner and the solid fuel burner of the combustion device will expand, so the flame will be localized and it is difficult to effectively use the entire furnace.

However, the solid fuel burner described in this embodiment uses the internal flame holder 1 whose cross-sectional shape is a wedge shape with a two equilateral triangle, so that the circulating flow 102 and fuel retained by the high-temperature combustion gas can be used. The contact of the jet 104 makes stable ignition and flame maintenance possible, and can reduce harmful emissions such as nitrogen oxides (NOx) or improve the combustion efficiency. The fuel jet 104 can be dispersed in a horizontal direction, which can be used in the furnace. The internal spread of flame can inhibit the localization of flame,

(Function 3) Generally speaking, in the case of a relatively ring-shaped inner flame holder and an outer flame holder, the circulating flow formed behind each is larger on the outer flame holder. On the other hand, if these flame holders are installed at the same time, the surrounding temperature will rise due to the influence of the flame formed behind the inner flame holder, and the circulation area behind the outer flame holder will be affected by the gas expansion. Therefore, the burner with the outer flame holder and the inner flame holder will have worse ignition flame maintenance results than the burner with only the outer flame holder.

However, the solid fuel burner described in this embodiment uses the internal flame holder 1 whose cross-sectional shape is a wedge shape with a two equilateral triangle, and can form a larger circulating flow 102 to make high-temperature combustion gas It is stably supplied to the vicinity of the external flame holder 2 to stably ignite and maintain the flame. [Example 2]

2A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the second embodiment. 2B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the second embodiment.

The solid fuel burner described in this embodiment is different from the solid fuel burner described in the first embodiment in that the shape of the constriction 5 is different.

In other words, in the solid fuel burner described in the first embodiment, the constriction 5 has a venturi-shaped structure that shrinks from the entire circumference, but the solid fuel burner described in this embodiment has a constriction The section 5 has a structure that shrinks in the vertical (up and down) direction and does not shrink in the horizontal (left and right) direction. The constriction 5 has a structure to narrow the flow path of the mixed gas 100 only in the vertical (up and down) direction.

The constriction part 5 described in this embodiment does not condense the particles toward the center in the horizontal direction. Therefore, it is easy to allow particles to circulate in the vicinity of the outer flame holder 2 in the horizontal direction. The direction of ignition is also easy.

In addition, the flow path of the mixed gas 100 is not reduced in the horizontal direction, so the axial length of the solid fuel burner can be shortened, and cost increase can be suppressed.

In addition, the reduction of the cross-sectional area of the flow path of the constriction 5 (compared to the venturi-type structure) is small, so the acceleration of the mixed gas 100 of the constriction 5 is suppressed, and the increase in particle velocity is also affected. inhibition. Therefore, the amount of wear on the inner wall of the fuel nozzle can also be reduced.

In addition, in the solid fuel burner described in this embodiment, the constriction angle (constriction angle) of the constriction portion 5 is appropriately designed in consideration of the balance between the internal flame maintenance and the peripheral flame maintenance. In addition, in the solid fuel burner described in this embodiment, the contraction angle (constriction angle) of the constriction portion 5 is smaller than that of the solid fuel burner described in the first embodiment.

In the constriction section 5, the particles are concentrated, and a high-concentration fuel flow (particles) is formed toward the center of the fuel nozzle. However, if the constriction angle (constriction angle) of the constriction section 5 is too large, the fuel ( The concentration of particles is not strong enough, and it may be difficult to ignite the outer flame holder 2. On the other hand, if the constriction angle (constriction angle) of the constriction part 5 is too small, the distance required to deform the outlet part 16 into a predetermined flat shape becomes longer, making the shaft length of the solid fuel burner It becomes longer, so the manufacturing cost of the burner increases.

The constriction angle (constriction angle) of the constriction part 5 is appropriately designed in consideration of the balance between the internal flame maintenance and the peripheral flame maintenance, so that the outlet part 16, even in the vicinity of the upper and lower outer flame holders 2 The high-concentration fuel flow (particles) can be circulated, and the ignition of the peripheral flame holder 2 can be ensured, and stable internal flame maintenance and external flame maintenance can be combined. [Example 3]

3A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the third embodiment. 3B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the third embodiment.

In the solid fuel burner described in this embodiment, in addition to the solid fuel burner described in the second embodiment, a horizontal blade 11 for blowing particles out of the horizontal direction is provided in the enlarged portion 6. In other words, the solid fuel burner described in this embodiment has horizontal blades 11 in the enlarged portion 6 that disperse the mixed gas 100 to the outer side in the horizontal direction.

The solid fuel burner described in this embodiment deletes the particle concentrator, so the fuel (particle) concentration near the outer flame holder 2 will decrease. In the outer peripheral flame holder 2 in the vertical direction, a large circulating flow 102 is formed. Therefore, even if the fuel (particle) concentration decreases, the particles can be trapped in the circulating flow 102 to perform ignition and maintain the flame. However, in the outer peripheral flame holder 2 in the horizontal direction, the circulating flow 102 is relatively small, so it may be difficult to ignite and maintain the flame.

Therefore, in the solid fuel burner described in this embodiment, horizontal blades 11 for condensing particles are provided on the outer side of the horizontal direction, so that the particles are concentrated in the vicinity of the outer periphery of the horizontal direction near the flame holder 2, and the outer periphery of the horizontal direction Flame maintenance becomes easy.

In the solid fuel burner described in this embodiment, the installation angle of the horizontal blade 11 is changed to adjust the fuel (particle) concentration near the inner flame holder 1 and the fuel near the outer peripheral flame holder 2 in the horizontal direction ( The concentration of particles) can be adjusted to the combustion state. By making the horizontal blade 11 a movable structure, the combustion state can be appropriately controlled in accordance with the operating state. [Example 4]

4A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the fourth embodiment. 4B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the fourth embodiment.

In the solid fuel burner described in this embodiment, in addition to the solid fuel burner described in the second embodiment, a rotating blade 12 for stirring particles is provided on the upstream side of the constriction portion 5. That is, the straight pipe portion 4 has a rotating blade 12 for stirring the mixed gas 100.

The mixed gas 100 flows through a long pipe (not shown) and is supplied to the straight pipe portion 4. At this time, it will pass through a large number of bends, but at this bend, only the particles will shift outward due to the centrifugal force, and the fuel (particle) concentration inside the pipe will vary. Because of the deviation of the fuel (particle) concentration, particles will gather in unexpected places on the upstream side of the constriction part 5 (straight pipe part 4), and it is difficult to ignite in the inner flame holder 1 or the outer flame holder 2 , Flame maintenance.

Therefore, in the solid fuel burner described in this embodiment, a swirling blade 12 for agitating particles is installed on the upstream side of the constriction section 5 (straight pipe section 4) to suppress the fuel (particles) flowing through the constriction section 5. ) Concentration deviation, and the internal flame holder 1 or the outer flame holder 2 can easily perform ignition and flame maintenance.

In addition, in this embodiment, although the rotating blade 12 is used as the structure for agitating the particles, it may also be a baffle plate (that diffuses the mixed gas 100 in the outer circumferential direction. For example, a conical structure), etc. shape. [Example 5]

5A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the fifth embodiment. 5B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the fifth embodiment.

In the solid fuel burner described in this embodiment, in addition to the solid fuel burner described in the second embodiment, a pipe is provided on the upstream side of the straight pipe portion 4, and the pipe has a curved portion connected to the straight pipe portion 4 13 (In this embodiment, it is a flat member that can be opened and closed for maintenance). The curved portion 13 of the pipe is provided with a guide (guide) that divides the flow path into the inner and outer sides of the curved portion 13 Lead board) 14. That is, there is a pipe on the upstream side of the straight pipe portion 4, the pipe having a bent portion 13 connected to the straight pipe portion 4, and the bent portion 13 of the pipe has a guide for dividing the mixed gas 100 in the centrifugal direction ( Guide board) 14.

When the mixed gas 100 circulates through the curved portion 13, only the particles are displaced outward due to centrifugal force. The provision of the guide (guide plate) 14 prevents the particles from deviating only to the outside of the curved portion 13, and the particles can be uniformly supplied in the vertical direction.

Thereby, the extreme fuel (particle) concentration deviation in the outlet portion 16 is suppressed, and the internal flame holder 1 or the outer peripheral flame holder 2 facilitates ignition and flame maintenance.

In addition, if a structure like a guide (guide plate) 14 is provided on the curved portion 13 of the pipe, there is no need to provide a structure like a rotating blade 12 on the straight pipe portion 4, and the solid fuel burner can be shortened. The shaft is long, so the manufacturing cost of the burner can be reduced. [Example 6]

6A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the sixth embodiment. 6B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the sixth embodiment.

In the solid fuel burner described in this embodiment, in addition to the solid fuel burner described in the third embodiment, a piping is provided on the upstream side of the straight pipe portion 4, and the pipe has a bent portion connected to the straight pipe portion 4 13 (In this embodiment, a flat member is a member that can be opened and closed for maintenance).

In addition, a particle dispersion plate 15 for dispersing particles is provided at the exit of the curved portion 13. That is, the straight pipe portion 4 has a particle dispersion plate 15 for dispersing the mixed gas 100.

The particle dispersion plate 15 is provided only on the outer side of the centrifugal direction of the curved portion 13. The particles are shifted to the outer side of the centrifugal direction of the curved portion 13, so the particles shifted to the outer side of the centrifugal direction are effectively dispersed by the particle dispersing plate 15. The particle dispersion plate 15 is provided only on the outer side of the centrifugal direction, thereby suppressing the reduction in the cross-sectional area of the flow path of the straight pipe portion 4 and also reducing the increase in the particle velocity of the straight pipe portion 4. Therefore, the amount of wear on the inner wall of the fuel nozzle can also be reduced.

The particle dispersion plate 15 allows particles to circulate through the fuel nozzle in a state of less deviation, and the horizontal blades 11 arranged downstream of the particle dispersion plate 15 can efficiently implement particle distribution, and the combustion state can be adjusted. [Example 7]

7A to 7F are detailed structural diagrams of the internal flame holder 1 described in FIGS. 1A to 6B of the present invention.

Fig. 7A is the basic structure of the internal flame holder described in the burner embodiment shown in Figs. 1A to 6B, which is a triangular column wedge-shaped structure. 7B to 7F are modification examples of the internal flame holder structure of FIG. 7A.

The structure of FIG. 7B is the basic structure of the internal flame holder shown in FIG. 7A, and the recess 105 is provided on the downstream side of the fuel jet 104 on the back surface. There is a recess 105 on the back of the internal flame holder to promote the mixing of the high-temperature air flow 103 and the fuel jet 104, and it is easier to ignite compared with the basic structure.

The structure of Fig. 7C-1 does not provide the back surface of the internal flame holder shown in Fig. 7A, but arranges the plate in a V-shaped structure so that the internal flame holder has a V-shaped structure, which is similar to Fig. 7B The same effect of the recessed portion 105 is to promote the mixing of the high-temperature airflow 103 and the fuel jet 104, and reduce the number of components used in the internal flame holder to achieve cost reduction.

In the structure of FIG. 7C-2, the barrier plate 106 is arranged at the front end of the V-shaped structure of FIG. 7C-1. A barrier 106 is provided at the front end of the plate-shaped member of the V-shaped structure to expand the cross-sectional area of the front end of the plate of the V-shaped structure, thereby promoting the mixing of the fuel jet 104 and the high-temperature airflow 103 more than in FIG. ignition.

Fig. 7D is a pentagonal corner post structure with a horizontal cross section of the internal flame holder. The internal flame holder of Fig. 7D has a larger volume in the horizontal cross-section compared with a triangular column of an equilateral triangle, and is excellent in abrasion resistance. Therefore, it is not necessary to use expensive ceramic materials and can be manufactured inexpensively. In addition, since it is excellent in wear resistance, it can be applied to, for example, the combustion of low-grade coal with a high ash content.

FIG. 7E is a structure without upper and lower notches in the recess 105 of FIG. 7B. In other words, the structure in which the top and bottom of the recessed portion of FIG. 7E is cut away is FIG. 7B. When this structure is compared with FIG. 7B, a strong negative pressure is formed by the recess 105, so the mixing of the high-temperature air flow 103 and the fuel jet 104 is further promoted, and the ignitability is excellent. It is the same as coal, which is an effective structure for the stable ignition of the fuel-starting burner that must have a strong negative pressure.

In the structure of FIG. 7F, the internal flame holder 1 and the recessed portion 105 and the air suction hole 107 for supplying air to the recessed portion 105 are provided. The air suction hole 107 is provided in the outer peripheral portion of the recessed portion. In FIG. 7F, in order to illustrate the function of the recess 105 and the ignition promotion of the oil-starting burner, the oil-starting burner nozzle 109 and the oil-starting burner gun 110 are also shown.

The oil fuel 111 is sprayed from the oil starter burner nozzle 109 toward the stove to form flame. Although solid fuel is not supplied at the time of oil start, solid fuel and/or air flow 108 is supplied, part of which flows from the air suction hole 107 to the periphery of the oil start burner nozzle 109 to generate an air flow 112 toward the recess.

In addition, a strong negative pressure is formed due to the recessed portion 105, so the high-temperature air flow 103 and the fuel jet 104 will flow into the recessed portion 105. Then, the air flow 112 toward the recess 105 promotes the ignition of the oil fuel, reduces dust, and suppresses the clogging (carbonization) of the oil starter burner nozzle 109.

In addition, the air suction hole 107 is a structure that sucks a small amount of air, so it is not limited to the hole structure, and may be another structure such as a slit. In addition, in FIG. 7F, the air suction holes 107 are provided in plural throughout the entire circumference of the depressed portion 105, but it may be on any side of the depressed portion, and the number of holes may be one or more. In addition, when it is not a hole but a slit, it may be provided over the entire circumference, and the number or length of the slit can be set arbitrarily.

Also, in this embodiment, although only the oil start burner nozzle 109 and the oil start burner gun 110 are shown in FIG. 7F, the same is true for the internal flame holders of FIGS. 7A to 7E, the oil start burner The nozzle has a structure that penetrates the internal flame holder as necessary, enabling stable combustion during solid fuel combustion and oil combustion.

In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modifications. For example, the above-mentioned embodiments are explained in detail for the purpose of explanation to facilitate understanding of the present invention, and are not necessarily limited to having all the structures described. In addition, a part of the structure of a certain embodiment may be replaced with a structure of another embodiment, and the structure of a certain embodiment may be added to the structure of another embodiment.

1: Internal flame holder 2: Peripheral flame holder 3: Center rod 4: Fuel nozzle straight pipe 5: Restriction of fuel nozzle 6: Fuel nozzle expansion 7: Guide sleeve 8: Upper and lower guide casing 9: Stove Wall 10: Bellows 11: Horizontal blade 12: Rotating blade 13: Bend 14: guide 15: Particle Dispersion Board 16: Fuel nozzle outlet 100: mixed gas 101: Air jet for combustion 102: Circulating flow 103: high temperature airflow 104: Fuel Jet 105: Depressed part 106: barrier 107: Air suction hole 108: solid fuel and/or air flow 109: Oil starter burner nozzle 110: Oil start burner gun 111: oil fuel 112: Air flow to the depression

FIG. 1A is an explanatory diagram showing a vertical center section of the solid fuel burner described in Example 1. FIG. FIG. 1B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in Embodiment 1. FIG. 2A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the second embodiment. 2B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the second embodiment. 3A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the third embodiment. 3B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the third embodiment. 4A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the fourth embodiment. 4B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the fourth embodiment. 5A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the fifth embodiment. 5B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the fifth embodiment. 6A is an explanatory diagram showing a vertical center section of the solid fuel burner described in the sixth embodiment. 6B is an explanatory diagram showing a horizontal center section of the solid fuel burner described in the sixth embodiment. FIG. 7A is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in Embodiment 1 to Embodiment 6. FIG. Fig. 7B is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in the first to the sixth embodiments. Fig. 7C-1 is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in the first to the sixth embodiment. FIG. 7C-2 is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in Embodiment 1 to Embodiment 6. FIG. Fig. 7D is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in the first to the sixth embodiments. FIG. 7E is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in Embodiment 1 to Embodiment 6. FIG. Fig. 7F is an explanatory diagram showing an embodiment of an internal flame holder that can be installed in any of the solid fuel burners described in the first to the sixth embodiments. It is an explanatory diagram showing the details of the internal flame holder in FIG. 7D, the flow of solid fuel, and the injection direction of starting oil fuel.

1: Internal flame holder

2: Peripheral flame holder

3: Center rod

4: Fuel nozzle straight pipe

5: Restriction of fuel nozzle

6: Fuel nozzle expansion

7: Guide sleeve

9: Stove Wall

10: Bellows

16: Fuel nozzle outlet

100: mixed gas

101: Air jet for combustion

102: Circulating flow

104: Fuel Jet

Claims (14)

A solid fuel burner, characterized in that it has: a straight pipe portion of a fuel nozzle for the mixed gas of solid fuel and its conveying gas to circulate; and a constriction portion of the fuel nozzle that will flow the mixed gas flowing through the straight pipe portion of the fuel nozzle The path is restricted; the fuel nozzle expansion part expands the flow path of the mixed gas flowing through the aforementioned fuel nozzle constriction part to a horizontal direction; the fuel nozzle outlet part is connected with the aforementioned fuel nozzle expansion part, and the outlet has a flat shape; A ring-shaped outer peripheral flame holder is provided in the outer circumferential direction of the outlet of the fuel nozzle; and an internal flame holder is provided at the outlet of the fuel nozzle and divides the mixed gas flowing through the enlarged portion of the fuel nozzle in the horizontal direction. The fuel nozzle constriction is a structure that shrinks only in the vertical direction. The solid fuel burner according to claim 1, which has a guide sleeve provided in the outer circumferential direction of the outer circumferential flame holder. The solid fuel burner according to claim 2, wherein the upper and lower guide sleeves are provided in the vertical direction of the outer circumference of the guide sleeve. The solid fuel burner according to claim 1, wherein the fuel nozzle enlarged portion has horizontal blades that disperse the mixed gas to the outer side in the horizontal direction. The solid fuel burner according to claim 1, wherein the straight pipe portion of the fuel nozzle is provided with a rotating blade for stirring the mixed gas. The solid fuel burner according to claim 1, wherein a pipe is provided on the upstream side of the straight pipe portion of the fuel nozzle, and the pipe has a curved portion connected to the straight pipe portion of the fuel nozzle, and the curved portion of the pipe has A guide that divides the aforementioned mixed gas in the centrifugal direction. The solid fuel burner according to claim 4, wherein a pipe is provided on the upstream side of the straight pipe portion of the fuel nozzle, and the pipe has a bent portion connected to the straight pipe portion of the fuel nozzle. It has a particle dispersion plate for dispersing the aforementioned mixed gas. The solid fuel burner according to claim 1, wherein the shape of the internal flame holder is a triangular column whose horizontal cross-section is an equilateral triangle. The solid fuel burner according to claim 1, wherein the internal flame holder is provided with a recessed portion on the back surface of the downstream side in the flow direction of fuel and/or air. The solid fuel burner according to claim 1, wherein the internal flame holder is formed by arranging a plate-shaped member having a V-shaped structure. The solid fuel burner according to claim 10, wherein the front end of the plate-shaped member of the V-shaped structure is provided with a baffle plate for expanding the cross-sectional area. The solid fuel burner according to claim 1, wherein the shape of the internal flame holder is a corner pillar structure with a pentagonal cross section in the horizontal direction. The solid fuel burner according to claim 9, wherein the internal flame maintainer is provided with cutouts above and below the recessed portion on the downstream side in the flow direction of fuel and/or air. The solid fuel burner according to claim 9, wherein the internal flame holder is provided with an air suction hole for supplying air to the recess.

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