JPH07233920A - Burning method for oxygen burner - Google Patents

Abstract

PURPOSE:To prevent generation of local high temperature part and to use a steel piece heating furnace, etc., for heating means by supplying pure oxygen of a theoretic burning oxygen amount or less from a periphery of fuel to primarily burn it in a fuel rich state, and supplying residual oxygen necessary for burning from its periphery to completely burn it. CONSTITUTION:A gas fuel supply tube 4 is opened at a center of a mixing chamber 3 provided at a center of a burner tile 2, and a primary oxygen supply tube 5 is opened at the chamber 3 at a periphery of the tube 4. On the other hand, a plurality of secondary oxygen supply tubes 6 are opened at an equal interval on the same circumference out of the chamber 3 of the tile 2. Fuel is supplied from the tube 4, pure oxygen of 10-50% of theoretical burning oxygen amount necessary for burning the fuel is supplied from the tube 5, and a fuel rich area A is formed at the front of the chamber 3. 90-50% of the residual pure oxygen is supplied from the tubes 6 toward an outer peripheral area of the area A, a fuel rich area B is formed and burned.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for burning an oxygen burner.

[0002]

2. Description of the Related Art In a conventional oxygen burner in which gaseous or liquid fuel is burned with pure oxygen having a theoretical burning oxygen amount, all necessary oxygen amount is supplied from the outer periphery of a fuel nozzle to burn the fuel. Compared with a burner that uses general combustion air, the oxygen burner 1) reduces the amount of flue gas and can save energy. 2) The flame temperature is high in the center of the burner (see Fig. 4). 3) Large dissociation latent heat. 4) Emissivity increases. 5) Since the flame temperature is high and the emissivity is high, the amount of radiant heat transfer is large. 6) No thermal NOX is generated. Etc. have many advantages. Especially because the flame temperature is high,
Oxygen burners have hitherto been widely used as heating means for steelmaking arc furnaces, glass melting furnaces and the like.

[0003]

However, when an oxygen burner is used as a heating means for a billet heating furnace or the like, as described above, since the flame temperature is high, the scale generation amount due to local overheating of the billet increases, Burning of the furnace wall occurs. Therefore, although the oxygen burner has many advantages, it has not been adopted as a heating means for a billet heating furnace. The present invention prevents the occurrence of local high temperature parts by slowing the burning rate of fuel, effectively utilizing other advantages,
An object of the present invention is to provide a combustion method of an oxygen burner that can be used for heating means such as a billet heating furnace.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is designed so that the combustion of an oxygen burner is performed by supplying pure oxygen in an amount equal to or less than a theoretical combustion oxygen amount from the periphery of a fuel to a primary combustion in a fuel rich state. In addition to performing the above, the remaining oxygen necessary for combustion is supplied from the surroundings to complete combustion. In addition, the amount of oxygen at the time of the primary combustion is set to be in the range of 10% to 50% of the theoretical amount of combustion oxygen for combustion.

[0005]

EXAMPLE A method of burning an oxygen burner according to the present invention will be described below with reference to FIGS. The oxygen burner 1 applied to the present invention is generally as shown in FIG.
That is, a mixing chamber 3 having an open front surface is provided at the center of the burner tile 2, and a gas fuel supply pipe 4 is provided at the center thereof.
And a primary oxygen supply pipe 5 opens in the mixing chamber 3 around the fuel supply pipe 4.

On the other hand, the mixing chamber 3 of the burner tile 2
A plurality of secondary oxygen supply pipes 6, that is, a total of four secondary oxygen supply pipes 6 in the present embodiment, are opened at equal intervals on the outside of the above. The fuel supply pipe 4 has a water cooling structure to prevent melting damage.

In the above structure, fuel is supplied from the fuel supply pipe 4, pure oxygen of 10% to 50% of the theoretical combustion oxygen amount necessary for combustion of the fuel is supplied from the primary oxygen supply pipe 5,
A fuel rich region A is created in front of the mixing chamber 3. Further, the remaining pure oxygen of 90% to 50% is supplied from the secondary oxygen supply pipe 6 toward the outer peripheral region of the fuel rich region A to form the fuel lean region B for combustion. In actual operation, a little more oxygen is supplied than the theoretical combustion oxygen. That is, in the burner central portion, since it is in the fuel rich region A, the fuel does not completely burn here, the temperature is lower than that in the case of the conventional method, and at the same time the flame becomes long, and the unburned portion is in the fuel lean region B. It gradually burns outward in accordance with the diffusion of oxygen and unburned components.

Therefore, the flame temperature in the primary combustion in the center of the burner depends on the amount of oxygen in the fuel rich region A, that is, the larger the amount of oxygen, the closer to complete combustion and the higher the temperature, and the amount of oxygen increases. The lower the temperature, the lower the temperature becomes.
As shown in, the temperature difference decreases in the furnace width direction. Further, a known swirling means may be provided in the secondary oxygen supply pipe 6 so that the secondary oxygen is swirled to improve mixing with the fuel in the fuel lean region B.

As a result of various experiments, as the heating means of the heating furnace, the oxygen amount at the time of primary combustion is 10 times the theoretical combustion oxygen amount.
It is preferably in the range of 50% to 50%. If it exceeds 50%, the flame temperature is as high as 1800 ° C, and local overheating occurs,
On the other hand, if it is less than 10%, the stable fuel rich region A is not formed, and it is unsuitable as a burner for heating a billet.

If the diameter of the mixing chamber 3 is d ₁ and the diameter of the concentric circle where the secondary oxygen supply pipe 6 is located is D ₁ , then D ₁ / d
It is desirable that ₁ = 1.5 to 5. If it is less than 1.5, the fuel rich region A is difficult to be formed. On the other hand, if it is more than 5, secondary oxygen is not sufficiently supplied to the outside of the fuel rich region A, and complete combustion is difficult, which is inconvenient. Because. The supplied oxygen may be preheated via an exhaust heat recovery device or the like, or the exhaust gas may be mixed to reduce NOX.

In the above embodiment, the fuel supplied to the oxygen burner 1 is a gaseous fuel, but when using a liquid fuel, the oxygen burner 1 may have the structure shown in FIG. That is, the liquid fuel and the atomizing oxygen are supplied to the fuel supply pipe 4 cooled by the cooling water, and the liquid fuel is ejected from the fuel supply pipe 4 in the atomized state. Others are Figure 1
Since it is the same as that shown in FIG. Also, the obtained flame temperature had a tendency similar to that shown in FIG.

[0012]

As is apparent from the above description, according to the present invention, the fuel is not completely burned at once but is gradually burned, so that the flame temperature at the burner center is lower than that of the conventional oxygen burner, and Since the gradually diffused fuel burns at the outer peripheral portion, a flame with little temperature difference from the center of the burner to the outside is formed (see FIG. 2). Therefore, even as a heating means for the billet heating unit, it is possible to use an oxygen burner combustion method that does not cause local overheating or damage to the furnace wall and has the advantages of the conventional oxygen burner.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining an oxygen burner to which the present invention is applied.

FIG. 2 is a diagram showing a flame temperature when the oxygen burner of FIG. 1 is applied.

FIG. 3 is a sectional view for explaining another oxygen burner.

FIG. 4 is a diagram showing a flame temperature of a conventional oxygen burner.

[Explanation of symbols]

1 ... Oxygen burner, 2 ... Burner tile, 3 ... Mixing chamber, 4 ...
Fuel supply pipe, 5 ... Primary oxygen supply pipe, 6 ... Secondary oxygen supply pipe, A ... Fuel rich region, B ... Fuel lean region.

Claims (2)

[Claims] 1. Complete combustion is performed by supplying pure oxygen in an amount equal to or less than the theoretical combustion oxygen amount from the periphery of the fuel to perform primary combustion in a fuel-rich state, and supplying the remaining oxygen necessary for combustion from the periphery thereof. A method for burning an oxygen burner, which comprises: 2. The method for burning an oxygen burner according to claim 1, wherein the amount of oxygen in the primary combustion is in the range of 10% to 50% of the theoretical amount of burned oxygen.