JPH0512578Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to improvements in burners for boilers, chemical industrial furnaces, etc. that use pulverized solid fuel.

[Conventional technology]

A conventional pulverized solid fuel-fired burner will be explained with reference to FIG. Figure 2 is a cross-sectional view of a conventional pulverized solid fuel-fired burner, where 01 is a separator and 02 is a separator.
is the lean mixture discharge pipe, 03 is the secondary air duct, 04
is a rich mixture nozzle, 05 is a lean mixture nozzle, 06
is the secondary air nozzle, 07 is the lean mixture discharge amount regulator, 08 is the mixture, 09 is the rich mixture, 10 is the lean mixture, 11 is the secondary air, 12 is the rich fuel flame, 13
14 indicates a light fuel flame, 14 indicates the inside of the furnace, 15 indicates a rich air mixture air box, 16 indicates a lean air mixture air box, and 17 indicates a secondary air air box.

The pulverized solid fuel is sent to the separator 01 as a mixture 08 with air from the pulverized solid fuel supply equipment (not shown).
sent to. The mixture 08 flow is given a swirling force in the separator 01, and is divided into a downward flow going below the separator 01 and an upward flow going upward.
The centrifugal force generated by the swirling force exerts a force on the fine particles inside to separate them from the mixture 08 and cause them to fall downward, resulting in a so-called rich mixture 09 in which the concentration of fine particles is higher on the downward flow side. On the other hand, the upward flow is a mixture of air and a group of fine powder particles having a small particle size on which the action of centrifugal force is weak, forming a lean mixture 10 with a low concentration of fine powder.

The rich mixture 09 is injected into the furnace 14 from a rich mixture nozzle 04 provided at the lower end of the separator 01, and is ignited by an ignition source (not shown) to form a rich fuel flame 12. The lean mixture 10 passes through the lean mixture discharge pipe 02 and is injected into the furnace 14 from the lean mixture nozzle 05 provided at the tip of the lean mixture discharge pipe 02, where it is ignited by the rich fuel flame 12 and combusted. served.

[Problem that the invention attempts to solve]

Although the flow rate ratio of the rich mixture 09 and the lean mixture 10 is adjusted by the lean mixture discharge amount regulator 07, it is not possible to adjust the fine powder concentration.

As with other fuels, the ignitability of pulverized solid fuel is promoted by keeping its ejection velocity below the flame propagation velocity, increasing the temperature of the mixture 08, and increasing the fines concentration of the mixture 08. It is known that

Generally, the amount of air/the amount of pulverized coal in the mixture 08 sent from a pulverized solid fuel supply facility (not shown),
That is, the A/C is 2 to 3, and since it is impossible to adjust the fine powder concentration with a conventional burner, the mixture cannot be heated any further.
The concentration cannot be increased, the temperature of the mixture 08 is the same as it is sent from the pulverized solid fuel supply equipment (approximately 100℃), and it is sent at a roughly determined A/C. Therefore, it may not be possible to adjust the ejection velocity of the mixture 08, especially the rich mixture 09, to below the flame propagation speed. In the case of pulverized solid fuel, stable combustion is difficult, and in order to achieve stable combustion, it is necessary to burn an easily combustible fuel as an auxiliary fuel.

As described above, in conventional pulverized solid fuel burners, it is difficult to form a stable flame because it is impossible to adjust the injection speed, fine powder concentration, and temperature of the rich mixture 09 that governs the ignitability of the flame. I have a problem with.

[Means for solving problems]

The purpose of the pulverized solid fuel-fired burner of the present invention is to solve the above-mentioned problems.It has a cylindrical structure that can be moved up and down on the outer periphery of the cylindrical part of the rich mixture outlet located below the separator to adjust the concentration of the rich mixture. A funnel-shaped mixer with a built-in container and a rich mixture swirling vane is provided, a cylindrical rich mixture nozzle is provided surrounding the funnel-shaped mixer, and a diverging nozzle is attached to the tip of the funnel-shaped mixer. It is characterized by a configuration in which a primary air swirling vane is provided in an annular part formed by a cylindrical part at the tip of the mixer so that the angle thereof can be adjusted.

[Effect]

With this configuration, a swirling flow effective for A/C and flame holding according to the fuel ratio is given to the rich mixture, and a stable rich fuel flame can be obtained.

〔Example〕

An embodiment of the pulverized solid fuel-fired burner according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a pulverized solid fuel-fired burner according to an embodiment of the present invention, and only the differences from a conventional pulverized solid fuel-fired burner in the figure will be explained.

A mixture 108 sent to the separator 101 from a pulverized solid fuel supply facility (not shown) is separated into a rich mixture 109 flowing downward and a lean mixture 110 flowing upward.

A cylindrical rich mixture concentration regulator 11 is installed on the outer periphery of the cylindrical portion of the exit of the rich mixture 109 below the separator 101.
A funnel type mixer 122 is provided, which incorporates a rich mixture swirling vane 123 and a rich mixture 109, which is fed from the lower part of the separator 101.
The primary air 121 and the funnel-shaped mixer 12 are sent into the rich air mixture wind box 115, forming a swirling flow by the rich air mixture swirling vanes 123.
2 and is spouted from the tip of the funnel-shaped mixer 122 into the furnace 114 while rotating. Rich mixture 10
9 and the primary air 121 is the mixing ratio of the separator 10
This is performed by a rich mixture concentration regulator 118 that can be operated from the outside using a concentration regulator operation stick 119.

A funnel-shaped mixer 122 is installed in the wind box 115 for rich mixture.
A rich mixture nozzle 104 is provided surrounding the rich mixture nozzle 104, and a diverging nozzle 124 is provided at the tip of the rich mixture nozzle 104. In addition, in the annular portion formed by the diverging nozzle 124 and the funnel-shaped mixer 122 provided inside it, the blade angle is adjusted from the outside of the rich air mixture wind box 115 by a primary air swirling blade angle adjustment rod 126. Adjustable primary air swirl vanes 125 are provided.

Through the primary air introduction pipe 120 to the rich air mixture wind box 1
A part of the primary air 121 sent to the nozzle 15 is sent to the funnel-type mixer 122 described above, and most of the remaining primary air 121 is sent to the nozzle 1 that widens toward the end.
24 and the funnel-shaped mixer 122 from the primary air swirl vane 125 provided in the annular portion
It is blown into 14.

As mentioned above, the most important thing for the ignition stability of the burner is to stabilize the ignition on the rich fuel flame 112 side, and for this purpose, it is necessary to increase the fine powder concentration of the rich mixture 109 and to increase the temperature of the rich mixture 109. It is necessary to increase the velocity of the rich mixture 109 and to lower the injection velocity of the rich mixture 109 to below the flame propagation velocity.

In the pulverized solid fuel-fired burner according to one embodiment of the present invention shown in FIG. , the temperature of the rich mixture 109 is also 1
The temperature can be increased in any way depending on the setting of the temperature of the next air 121. Further, the primary air 121 used for mixing with the rich mixture 109 is supplied to the funnel type mixer 1.
A swirling force is applied by a rich mixture swirling vane 123 provided at the inlet on the primary air 121 side of 22,
Even after being mixed with the rich mixture 109 in the funnel mixer 122, it is supplied to the furnace 114 as a swirling flow.

On the other hand, the remaining primary air 121 is generated by a swirling force by a primary air swirling vane 125 provided in an annular portion formed by a diverging nozzle 124 provided at the tip of the rich mixture nozzle 104 and a funnel-shaped mixer 122. The primary air 121 is given and blown into the furnace 114, but because the shape of the air outlet is wide at the end, the primary air 121 blown into the furnace 114 forms a large vortex. A mixture of the rich mixture 109 and primary air 121 blown from the funnel mixer 122 is caught in this vortex, and the pulverized fuel rides on the vortex and spreads. As a result, the axial velocity of the pulverized fuel decreases, and the amount of heat received from the radiation from the inside of the furnace 114 increases, forming a stable fuel-rich flame 112.

In addition, in Fig. 1, 102 is a light mixer discharge pipe,
103 is a secondary air duct, 105 is a lean mixture nozzle, 106 is a secondary air nozzle, 107 is a lean mixture discharge amount regulator, 111 is secondary air, 113 is a lean fuel flame, 116 is a lean mixture wind Boxes 117 each represent a secondary air box, which has the same functions as conventional ones.

[Effect of idea]

Since the pulverized solid fuel firing burner according to the present invention is constructed as described above, the pulverized fuel concentration and temperature of the rich mixture can be freely set, and the primary air 1
A rich mixture 109 is created by the large vortex formed by 21.
As the pulverized fuel in the burner diffuses, its axial flow velocity decreases, the amount of radiant heat received from the furnace interior 114 increases, the ignitability of the rich fuel flame 112 improves, and the combustion of the burner as a whole becomes stable, etc. The effect is produced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a burner burning pulverized solid fuel according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a conventional burner burning solid fuel powder. 101... Separator, 104... Rich mixture nozzle, 109... Rich mixture, 110... Lean mixture,
112... Rich fuel flame, 118... Rich mixture concentration regulator, 122... Funnel type mixer, 123... Rich mixture swirling vane, 124... Widening nozzle, 1
25...Primary air swirl vane.

Claims (1)

[Scope of utility model registration request] A pulverized solid fuel is used as a fuel, the pulverized solid fuel is injected downward, and a cyclone separator divides the mixture of the pulverized solid fuel and air into two types of mixtures with different concentrations. The lean mixture is injected from a rich mixture nozzle installed at the bottom of the cyclone type separator toward a flame formed by the rich mixture and is blown into a pulverized solid fuel-fired burner for combustion. A funnel-type mixer that is vertically movable and has a built-in cylindrical rich-air mixture concentration regulator and a rich-air mixture swirl vane is provided on the outer periphery of the cylindrical portion of the rich-air mixture outlet, and is provided surrounding the funnel-type mixer. A diverging nozzle is attached to the tip of a cylindrical rich mixture nozzle, and a primary air swirling vane is provided in an annular portion formed by the divergent nozzle and a funnel-shaped mixer so that the vane angle can be adjusted. Fine powder solid fuel fired burner.