JPS5929906A - Kiln burner - Google Patents

Abstract

PURPOSE:To improve combustion of a kiln burner, by a method wherein, without the use of a mechanical booster, a high-temperature secondary air recovered from a cooler is utilized effectively, and the fuel is efficiently agitated and mixed under a condition in which there is less quantity of a primary air. CONSTITUTION:A solid fuel passes a mixture conduit 4 and a rotary blade 8 togetherwith the air, and a primary air sucked from a fan 10 is jetted at a high speed into a kiln 2 from the end of a kiln burner 1 through a conduit 5 and a rotary blade 9. By an ejector effect caused thereby, a high-temperature secondary air sucked through a secondary air conduit 6 is jetted in the kiln 2, and thereby the high-temperature scondary air can be sucked, without the use of a mechanical booster, from a cooler 3 through utilization of a suction force produced due to vacuum. Thus, the high-temperature secondary air of the cooler 3 is jetted from the secondary air conduit 6 into an annular fuel stream jetted through a mixture conduit 4, and this causes sufficient mixture and agitation of the fuel and high-temperature air, resulting in improvement of not only the ignition ability of the fuel but also a consumption condition.

Description

[Detailed Description of the Invention] This invention relates to a rotary kiln for burning cement and lime (
The present invention relates to a fuel combustion burner (hereinafter referred to as a kiln burner) for a kiln (hereinafter referred to as a kiln burner).

Conventionally, as shown in Fig. 1, fuel blown from a kiln burner is passed through a primary air conduit where it is blown together with fuel A' from the burner body (1'), and an object to be heated that is connected to the rear stage of the kiln (2'). Alternatively, it is combusted with high-temperature secondary air C' recovered from a cooler (hereinafter referred to as cooler) (3') for the object to be fired (hereinafter referred to as chestnut 7). - Secondary air B' diffuses the fuel in the kiln (2') and secondary air C
’ is blown in with a high-velocity jet to promote mixing. For that, I have to boost the pressure with a blower.
Generally, room temperature air is used. Further, even if a blower capable of withstanding high temperature air is used, the temperature of the primary air is limited to 600η at most. It is thermoeconomically advantageous to reduce the amount of secondary air and increase the ratio of high-temperature secondary air used after cooling the clinker. There is a limit to its reduction, as mixing is significantly reduced and combustion efficiency deteriorates. In addition, in this type of kiln burner, even if the optimum amount of primary air blown in by the high-speed jet is secured, the central part of the burner tip (=I
The fuel and secondary air were not sufficiently mixed near each other, and the tendency for a long flame due to combustion delays was unavoidable.

This invention solves the above-mentioned drawbacks, effectively utilizes high-temperature secondary air recovered from the cooler without using a mechanical booster such as a blower, and efficiently uses fuel with a small amount of primary air. The present invention provides a kiln burner that can stir and mix the fuel and air to significantly improve combustion, and is composed of a fuel and air mixture conduit, a primary air conduit provided to surround the mixture conduit, and the mixture conduit. and a secondary air conduit provided approximately in the center of the kiln, and due to the ejector effect of the fuel and air blown out in high-speed jets from the mixture guide W and the secondary air conduit to the kiln, the air is cooled from the secondary air conduit. The high-temperature secondary air is sucked in and blown into the kiln.

Hereinafter, one embodiment of a kiln burner using solid powder fuel will be described with reference to the drawings.

2 and 3, the kill/burner (
1) includes a fuel-air mixture conduit (4) and a primary air conduit (5) provided so as to surround the mixture conduit (4).
) and a secondary air conduit (6) provided approximately in the center of the mixture conduit (4), and the secondary air conduit (6) is connected to the cooler (8) via a damper (7). has been done.

On the other hand, swirl vanes (8) and (9) are provided at the tips of the mixture conduit (4) and the secondary air conduit (5), respectively, in order to improve mixing with the air approaching from around the kiln burner (1). However, it is also possible to omit either one or both.

In the kiln burner (1) having the above configuration, solid fuel is passed along with air from a separately provided feeder (not shown) through the mixture conduit (4) and the swirling vane (8), and is killed/( 2) Being blown inward. On the other hand, the secondary air is sucked from the primary air 7 Oe and is blown into the FTgJ Jukukiru/(2) through the primary air conduit (6) and the swirl vane (9).This primary air and solid fuel The secondary air conduit (6) is caused by the ejector effect trap as the air containing
), the high temperature secondary air of the cooler (8) is sucked in and blown out to the kiln (2). That is, when air containing primary air and solid fuel is ejected from the tip of the kiln burner (1) at high speed, a large vacuum is generated at the tip of the intermediate heating section of the kiln burner (1). Utilizing the suction force generated by the vacuum, high-temperature secondary air from the cooler (3) can be suctioned without the need for a mechanical pressure increase device such as a blower, which has poor heat resistance.

Therefore, heat is exchanged with the clinker, and the high temperature air of the cooler (3) drawn from around the kiln burner (11
With dotted arrow C), the hot secondary air of the cooler (8) is transferred from the secondary air conduit (6) provided in the central part of the kiln burner (1) into the annular fuel stream ejected from the mixture conduit (4). Since air is blown out, the fuel and high-temperature air are sufficiently mixed and stirred, and not only the ignitability of the fuel but also the burnout are significantly improved. In addition, the conventionally known black zone is hardly seen, and the flame is significantly shortened.

By adjusting the damper (7), the amount of high temperature secondary air blown out from the secondary air conduit (6) can be adjusted and the flame can be made to have an appropriate length.

In addition, although powdered solid fuel was explained in the example,
By replacing the mixture conduit (4) with a burner gun, it can also be applied to liquid burners such as heavy oil.

As explained above, the kiln burner of the present invention can effectively utilize the high-temperature secondary air of the cooler without using a mechanical pressure booster such as a blower under a small amount of primary air. It can be operated without any problems even at high temperatures, and combustion efficiency and thermal efficiency are significantly improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram using a conventional kiln burner. Fig. 2 is an explanatory diagram using a kiln burner according to the present invention. Fig. 3 is an enlarged sectional view of the kiln burner. In the figure, (1)... Kiln Burna (2)...Kill
(8)...Li-ra (4)...Mixture conduit (5)...-Secondary air conduit (6)...Secondary air conduit (7)...Damper . Agent Hisashi 1) Hidetaka Figure 1 - Figure 2 Figure 3

Claims (1)

[Claims] It consists of a fuel-air mixture conduit, a primary air conduit provided so as to surround the mixture conduit, and a secondary air conduit provided approximately at the center of the mixture conduit, the mixture conduit and - The high-temperature secondary air of the cooler is sucked from the secondary air conduit and blown out to the kiln by the ejector effect of the fuel and air being blown out from the secondary air conduit to the kiln in a high-speed jet. Kilnburner.