JPH03241229A - Ignition torch - Google Patents

Abstract

PURPOSE:To prevent a reduction of an igniting characteristic and a flame holding characteristic by a method wherein an atomizer and a flame detector are mounted within an inner sleeve and cone-like flow regulating plates of which diameters are gradually increased in an injection direction of combustion air are arranged at an inner extreme end of a furnace between an inner sleeve and an outer sleeve. CONSTITUTION:An atomizer 10, an igniter 11, a flame detector 12 and an impeller 15 are arranged inside an inner sleeve 17. Cone-like flow regulator plates 21 and 22 of which diameters are gradually increased toward an injecting direction of combustion air 24 are arranged at an extreme end inside a furnace between the inner sleeve 17 and an outer sleeve 18. Accordingly, it is possible to restrict a flowing-in of the combustion air into a central part of a torch sleeve 16 under an action of sealing air introduced into the inner sleeve 17 through a feeding-in hole 20. With such an arrangement, it is possible to form a recirculation region required for an ignition and a flame holding at a central part of the torch sleeve 16.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an ignition torch, and particularly relates to an ignition torch that is suitable for preventing deterioration in ignitability and flame stability even when the operating conditions of the main burner change. Regarding the ignition torch.

[Conventional technology]

A pulverized coal burner, which is a combustion device equipped with this type of ignition torch, is shown in Figure 4, and conventional ignition torches are shown in Figures 5 and 6.
As shown in the figure.

The pulverized coal burner has a pulverized coal nozzle 1 as shown in Fig. 4.
, secondary air throat 2, tertiary air throat 3, 2
It is comprised of a secondary air register 4, a secondary vane 5, a tertiary air register 6, and an ignition torch 7, which are installed in a wind box 23.

Pulverized coal, which is fuel, is conveyed by primary air and is ejected from a pulverized coal nozzle 1 into the furnace.

Combustion air to the pulverized coal nozzle 1 includes primary air for conveying the pulverized coal, secondary air supplied from the secondary air throat 2, and tertiary air supplied from the tertiary air throat 3. The secondary air and tertiary air are introduced from the wind box 23.

The secondary air is supplied to a secondary air register 4 and a secondary vane 5.
A swirling force is applied to the air, and the air is ejected from the secondary air throat 2 into the furnace.

The tertiary air is given a swirling force by the tertiary air register 6 and is blown out from the tertiary air throw 13 into the furnace.

In addition, the fuel/combustion consists of pulverized coal ejected from the pulverized coal nozzle 1 (along with secondary air), secondary air ejected from the secondary air throat 2, and tertiary air ejected from the tertiary air throat 3. The γ-Kon Aiki of the air for use is ignited by an ignition torch 7. Also, when extinguishing a fire, the ignition torch 7 is ignited in order to burn the remaining coal.

By the way, a conventional ignition torch that uses light oil as fuel includes a torch sleeve 8, an atomizer 10, an igniter 11, a flame detector 12, and the torch sleeve 8, as shown in FIGS. The atomizer 10 and the igniter 11 are mounted on a plate 13, this mounting includes a fluid pressure cylinder 14 connected to the plate 13, and an impeller 15.

The torch sleeve 8 has a ventilation hole 9 for combustion air 24.
is provided.

The atomizer 10, igniter 11, and flame detector 12 are installed within the torch sleeve 8, and are attached to a plate 13.

The fluid pressure cylinder 14 is attached via a plate 13 so that the atomizer 10, igniter 11, and flame detector 12 are pushed out into the furnace when used for ignition, and pulled out to the outside of the furnace when not used.

The impeller 15 is installed inside the torch sleeve 8 at the end inside the furnace.

When igniting the ignition torch 7, the fluid pressure cylinder 14 is driven toward the approach side, and the atomizer 10, igniter 11, and flame detector 12 are pushed out into the furnace through the plate 13, and are placed at a predetermined position in the furnace. inserted.

Light oil, which is the fuel for the ignition torch 7, is ejected into the furnace from the atomizer 10.

The combustion air 24 of the ignition torch 7 is fed to the pulverized coal nozzle 1 through a common wind box 23 with secondary air and tertiary air.
A ventilation hole 9 introduced from the torch sleeve 8 and provided in the torch sleeve 8
It enters the torch sleeve 8 and is supplied around the atomizer 10 through the impeller 15.

The mixture of the light oil, which is the fuel, and the combustion air 24 is ignited by the igniter 11, the ignition is detected by the flame detector 12, and a flame 26 shown in FIG. 5 is formed. The flame 26 is ignited and stabilized by a recirculation region formed around the front end of the impeller 15.

After the flame 26 of the ignition torch 7 ignites the mixture of fuel and combustion air in the pulverized coal burner, the fluid pressure cylinder 14 is driven to the return side, and the atomizer 10 and igniter 11 are attached via the plate 13. and flame detector 12 are pulled out to the outside of the furnace. Thereby, caulking and the like of the atomizer 10 can be prevented.

[Problems to be Solved by the Invention] The flame 26 of the ignition torch 7 is ignited and flame-stabilized by the recirculation area generated by the impeller 15, but the combustion air 24 to the ignition torch 7 is supplied from the wind box 23. Therefore, the draft inside the wind box 23 changes depending on the operating conditions of the main burner, and the air velocity and flow rate of the combustion air 24 to the impeller 15 change.

In addition, due to manufacturing problems, it is inevitable that the space between the impeller 15 and the torch sleeve 16, the impeller 15 and the atomizer IO,
A clearance is required between the igniter 11 and the frame detector 12. Therefore, when the draft inside the wind box 23 becomes high, the air flow velocity at the center of the torch sleeve 16 increases, and a sufficient recirculation area is not formed on the front end surface side of the impeller 15, leading to ignition failure of the ignition torch 7 and maintenance. There was a problem that blow-out occurred due to a decrease in flammability.

An object of the present invention is to provide an ignition torch whose ignitability and flame stability do not deteriorate even when the operating conditions of the main burner change.

[Means to solve the problem]

The purpose is to configure the torch sleeve with an inner and outer double sleeve, form a combustion air passage between the inner sleeve and the outer sleeve, and provide a seal air introduction hole to restrict the inflow of combustion air into the inner sleeve. At least an atomizer, an igniter, and a flame detector are installed inside the inner sleeve, and a trumpet-shaped rectifier whose diameter gradually increases in the direction in which the combustion air is ejected is installed at the tips of the inner sleeve and the outer sleeve inside the furnace. This is achieved by providing a plate.

[Function] In the present invention, the torch sleeve is composed of an inner and outer double sleeve, and an atomizer, an igniter, and a flame detector are installed inside the inner sleeve, and the inner sleeve is provided with combustion air to the center of the torch. A seal air introduction hole is provided to regulate the inflow. Therefore, the amount of combustion air introduced into the inner sleeve in which the atomizer, igniter, and flame detector are installed is reduced, so that the influence of drafts in the wind box can be reduced.

Furthermore, a passage for combustion air is formed between the inner sleeve and the outer sleeve, and a trumpet-shaped rectifying plate whose diameter gradually increases in the direction in which the combustion air is ejected is provided at the tips of the inner and outer sleeves inside the furnace. Therefore, the combustion air comes from the wind box,
This combustion air creates a recirculation area in the center of the torch sleeve as it passes through a passage formed between the outer sleeves and is blown out at an outward angle to the central axis of the torch sleeve by a trumpet-shaped baffle. It is formed.

In addition, because the amount of combustion air flowing into the inner sleeve is small due to the effect of sealing air, the difference between the outer circumferential air flow velocity of the inner sleeve and the internal air flow velocity increases, creating a negative pressure area in the center of the torch sleeve. This facilitates the formation of a more stable recirculation region.

Furthermore, since the inner and outer sleeves are provided with a rectifying plate in the form of a hollow, even if the draft inside the wind box becomes high and the air flow rate ejected from the tip of the torch sleeve increases, Since the combustion air is ejected at an outward angle to the central axis of the torch sleeve, the recirculation area is not reduced; on the contrary, the faster the combustion air flow rate, the more the outer peripheral air flow rate of the inner sleeve and the inner air The difference with the flow velocity becomes larger, the recirculation area expands, and ignitability and flame stability improve.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an axial sectional view showing one embodiment of the present invention, and FIG.
The figure is a view taken along the ■-■ arrow in FIG.

In the embodiments of the present invention shown in FIGS. 1 and 2, the same members as in the conventional ignition torch shown in FIGS. do.

In the embodiment shown in FIGS. 1 and 2 of the present invention, the torch sleeve 16 is constructed of an inner and outer double sleeve including an inner sleeve 17 and an outer sleeve 18.

A passage 19 for combustion air 24 is formed between the inner sleeve 17 and the outer sleeve 18.

The inner sleeve 17 is provided with an introduction hole 20 for sealing air. This introduction hole 20 introduces only seal air 25 into the inner sleeve 17 and restricts excess combustion air 24 from flowing in. Furthermore, an atomizer 10, an igniter 11, a flame detector 12, and an impeller 15 are installed inside the inner sleeve I7.

At the tips of the inner sleeve 17 and the outer sleeve 18 inside the furnace, trumpet-shaped rectifying plates 21 and 22 are provided, the diameter of which gradually increases in the direction in which the combustion air 24 is ejected.

In the ignition torch of the embodiment described above, sealing air 25 is introduced into the inner sleeve 17 through the introduction hole 20 provided in the inner sleeve 17 . Therefore, combustion air 2
4 does not flow very much.

On the other hand, the combustion air 24 comes from the wind box 23,
through a passageway 19 formed between the outer sleeves 17, 18;
The gas is ejected at an outward angle with respect to the central axis of the torch sleeve 16 through a trumpet-shaped baffle plate 21.22 provided at the tips of the inner and outer sleeves 17.18 on the inside of the furnace.

In this way, the seal air 25 is inside the inner sleeve 17.
Since the combustion air 24 does not flow in much due to the action of , the air flow velocity inside the inner sleeve 17 is as slow as 2 to 5 m/s, and the air flow rate is also small, so that it is hardly affected by the draft inside the wind box 23.

Furthermore, since the combustion air 24 is blown out at an outward angle with respect to the central axis of the torch sleeve 16 by the trumpet-shaped rectifying plate 21.22 provided on the inner and outer sleeves 17.18, this combustion air 24 This reliably forms a recirculation region 27 in the center of the torch sleeve 16, that is, around the front end of the impeller 15, where the air flow necessary for igniting the ignition torch and holding the flame occurs at a low velocity and high temperature.

Even if the draft inside the wind box 23 increases and the flow velocity of the combustion air 24 increases, the inner sleeve 1
Since the amount of combustion air 24 flowing into the interior of the torch sleeve 16 is small, the difference between the outer peripheral air flow velocity and the internal air flow velocity of the inner sleeve 17 becomes large, and a negative pressure area is likely to occur in the center of the torch sleeve 16. , thus a more stable recirculation area 27 is formed.

Furthermore, even if the draft inside the wind box 23 becomes high and the air flow in the axial direction of the torch sleeve 16 becomes faster, the trumpet-shaped rectifier plates 21 provided at the tips of the inner and outer sleeves 17 and 18. 22, the combustion air 24 is ejected at an outward angle with respect to the central axis of the torch sleeve 16, resulting in a negative pressure in the center of the torch sleeve 16, and furthermore, the outer peripheral air flow rate of the inner sleeve 17 and the inner As the difference between the first part and the air flow rate increases, the area of negative pressure in the center of the torch sleeve 16 becomes larger and larger due to the difference in flow rate, so that a stable and wide recirculation area 27 is formed.

The other functions of this embodiment are similar to those of the conventional ignition torch.

Next, FIG. 3 is an axial sectional view showing another embodiment of the present invention.

In the embodiment shown in FIG. 3, the insertion/extraction operation rod 2
An outer sleeve 18 is attached to the outer sleeve 8, and the outer sleeve 18 is configured to be movable in the central axis direction.

In this embodiment, by moving the outer sleeve 18 in the axial direction via the insertion/extraction operation shaft 28, combustion air is formed between the rectifying plate 2 of the inner sleeve 17 and the rectifying plate 22 of the outer sleeve 18. The area of the opening through which 24 is ejected can be adjusted appropriately.

Other configurations and functions of the embodiment shown in FIG.
This embodiment is similar to the embodiment shown in FIG.

[Effects of the Invention] According to the present invention, the torch sleeve is composed of an inner and outer double sleeve, a passage for combustion air is formed between the inner and outer sleeves, and the inflow of combustion air into the inner sleeve is restricted. Since a sealing air introduction hole is provided, the sealing air introduced into the inner sleeve through this introduction hole can restrict the inflow of combustion air into the center of the torch sleeve. This has the effect of forming a recirculation area necessary for ignition and flame stabilization in the center of the torch sleeve, without being affected by drafts in the wind box caused by changes in the operating conditions of the main burner. A trumpet-shaped rectifier plate is installed at the inner tip, and the combustion air passes through the passage formed between the inner and outer sleeves and is ejected at an outward angle to the center axis of the torch sleeve via the rectifier plate. This ensures that this combustion air creates a recirculation area in the center of the torch sleeve, while also increasing the draft in the wind box and increasing the air flow rate from the tip of the torch sleeve. In this case, the difference between the outer circumferential air velocity and the internal air velocity of the inner sleeve increases, and a negative pressure area is likely to occur in the center of the torch sleeve, which makes it possible to form a more stable recirculation area. be.

[Brief explanation of drawings]

FIG. 1 is an axial sectional view showing one embodiment of the present invention, and FIG.
3 is an axial sectional view showing another embodiment of the present invention, and FIG. 4 is a pulverized coal burner, which is a combustion device equipped with an ignition torch. axial cross-section of
FIG. 5 is an axial cross-sectional view of a conventional ignition torch, and FIG. 6 is a view taken along the line VI-Vl in FIG. 10...Atomizer, 11...Igniter, 12.
...Frame detector, 13... Mounted on board, 14...
・Fluid pressure cylinder, 15... Impeller, 16... Torch sleeve, 17... Inner sleeve, 18... Outer sleeve, 19... Combustion air passage, 20... Introduction of seal air hole, 21.22... rectifier plate provided on inner and outer sleeve, 23... wind box, 24...
... Combustion air, 25... Seal air, 26... Flame, 27... Recirculation area.

Claims (1)

[Claims] (1) The torch sleeve consists of an inner and outer double sleeve,
A passage for combustion air is formed between the inner sleeve and the outer sleeve, a seal air introduction hole is provided in the inner sleeve for regulating the inflow of combustion air, and at least an atomizer, an igniter, and a flame detector are installed inside the inner sleeve. At the tips of the inner sleeve and outer sleeve inside the furnace,
An ignition torch characterized by being provided with a trumpet-shaped baffle plate whose diameter gradually increases in the direction in which combustion air is ejected.