DE1007931B - Burners for industrial furnaces - Google Patents

Description

GERMAN

The invention relates to a burner for industrial furnaces, in which a combustion medium (z. B. Gas) axially and another (eg., Air) to the axial direction inclined in the mixing space occur and the flame characteristics are \ ^r eränderbar by changing the mixing speed .

When burning flow media, e.g. B. in industrial furnaces, the flame properties influenced by changing the mixing speed and generally by influencing the Mi sch process will. For this purpose you can z. B. the absolute and relative speed of the The jets emitted by the burner, regulate the jet angle, the twist and the impact of the jets.

In a frequently used embodiment of burners, a first combustion medium inserted axially and another inclined to the axial direction into the mixing chamber. With one type of this Burner, the axial tangential flow burners, the air by tangential entry into the mixing chamber set in fast circles and rotates around the gas core flowing in axially. To the mixing speed To be able to influence within certain limits, z. B. the burner with devices be provided, which allow a displacement of the gas nozzle. These burners have the disadvantage that a regulation of the flame properties directly influences the burner output, so that additional Control processes are required in order to keep the burner output essentially constant in the case of flame control to hold if so desired.

The invention aims at a particularly advantageous embodiment of a burner in which a combustion medium enter the mixing chamber axially and another inclined to the axial direction. In particular The invention aims to adjust the flame length without significantly changing the quantitative ratio the fuel (fuel and air) and the burner output.

According to the invention, a burner for industrial furnaces is provided in which a combustion medium (e.g. gas) enter the mixing chamber axially and another (e.g. air) inclined to the axial direction and the flame properties can be changed by changing the mixing speed, the Axial flow is divided into at least two essentially concentric partial flows and a throttle device is provided in the flow path of one of the partial flows is.

A throttle device arranged at the branching point of two partial flows is preferably used used, the optional throttling, possibly a shut-off of one of the partial flows permitted.

Burners for industrial furnaces

Applicant:

"OFU" Ofenbau-Union GmbH,
Düsseldorf, Graf-Adolf-Str. 67

Julius Müller, Essen,
has been named as the inventor

According to a preferred embodiment, the outer part of the axial flow can be divided into several on the circumference distributed exit points be divided between the two partial flows of the inclined to the axial direction entering Partial flow enter the mixing chamber. The exit points of the outer Part of the axial flow inclined to the axial direction enter the mixing chamber.

The inventive design is compared to the known burners in which the Flame length can be adjusted by changing the relative speed of the two streams, in advantageously achieved that the adjustment of the flame length does not significantly change the quantitative ratio the fuel (fuel and air) and the burner output, because only one Part of the fuel gas or possibly air volume gets a different exit speed while the greater part of it retains its original exit speed.

It is particularly advantageous when the axial flow is divided into two concentric partial flows the throttle device is provided in the flow path of the outer partial flow, because then the Exit speed of the outer partial flow can be throttled in such a way that the tangential flow can penetrate faster into the axial flow and thus accelerate the mixing processes and the Flame can be shortened.

In the control according to the invention, it must be taken into account that in the inflow cross-section of the axially flowing medium inevitably adjust throttle losses, so that a throttling, according to the invention is carried out in part of the axial flow, leading to an increase in the flow velocity of the other partial flow, since the line pressure for this medium is at the end of the inflow cross-section elevated.

709 508/178

In the drawings, two gas burners are shown as exemplary embodiments of the invention.

Fig. 1 shows in longitudinal section an embodiment of a burner according to the invention;

Fig. 2 is a cross section along the line II-II of Fig. 1;

Fig. 3 shows a further embodiment in longitudinal section;

FIG. 4 is a cross section along the line IV-IV of FIG. 3.

The gas passes through a nozzle 1 into a chamber 2. The chamber 2 is in through a wall 3 two smaller chambers 4 and 5 divided. The gas emerges from the chamber 4 into an annular nozzle 6 and from the chamber 5 into an annular nozzle 7 surrounding the nozzle 6. In the chamber 5 is a Throttle valve 9 arranged. If you close this flap, the flow velocity of the Gas in the nozzle 6 and thus the kinetic energy of the gas jet of this nozzle increases because of the pressure drop decreases in the supply line when the flow rate is reduced.

The air enters through a nozzle 10, is distributed in an annular channel 11 and passes through against the Burner axis inclined slots 12 in the mixing space. The slots 12 can be directed so that at the mixture creates a vortex.

In the interior of the burner, in a manner known per se, a cleaning and observation opening 13 be provided, which can be closed by a cover 14 provided with a sight glass.

Instead of the chamber 5, the throttle valve 9 can also be provided in the chamber 4 or in both chambers be, or it is arranged on the partition 3, a common throttle valve 15, as they is shown in FIG.

In the embodiment of the burner shown in FIGS. 3 and 4, the edge of the outer nozzle 18 is undulating designed so that an alternating sequence of flow cross sections 16 and 17 is created by which the cross-sections 16 from the nozzle 10 with air and the cross-sections 17 from the annular space 5 be fed.

By appropriately shaping the flow guides, the flowing media can swirl and a direction tangential to a common vortex circle can be imparted.

Three characteristic setting options of the burner according to FIGS. 3 and 4 are described below, any intermediate settings are also possible.

1. In the closed position shown in the drawing by the throttle valve 15, the burner works with high kinetic energy of the axially flowing medium. The gas and air are mixed through the injector effect of the gas jet. The flame is relatively long.

2. When the throttle valve 15 is in the middle position, the axially flowing gas is fully available as a result of the standing gas cross-section slower. Due to the described design of the outer gas nozzle 18 the gas and air flows are partially interlinked, so that a better premixing takes place. The flame is relatively short because the tangential flow can penetrate the axial flow faster and thus the mixing process is accelerated.

3. In the position of the throttle valve 15 shown in dash-dotted lines, the gas is forced, exclusively exit through the gas nozzle cross-sections located between the air nozzles. Gas and air become divided into alternately adjacent strands and in a vortex in the mixed cross-section blown into the burner. A relatively short flame is also generated in the process. This setting is advantageous for small loads.

The invention is not limited to the gas burners described with reference to the drawings. So can z. B. the inner chamber of the axially flowing medium instead of the circular cross-section also have a circular cross-section, or the air in nozzle 1 and the gas in Nozzle 10 are initiated. Instead of the two shown, several concentric annular chambers can also be used be provided.

Claims (4)

Patent claims 1. Burner for industrial furnaces in which a combustion medium (e.g. gas) is axial and a other elements (e.g. air) inclined to the axial direction enter the mixing chamber and the flame properties can be changed by changing the mixing speed, characterized in that that the axial flow is divided into at least two essentially concentric partial flows and in A throttle device is provided for the flow path of one of the partial flows. 2. Burner according to claim 1, characterized by one at the branch point of two substreams arranged throttle device, optionally a throttling, possibly a shut-off one of the partial flows allowed. 3. Burner according to claim 1 or 2, characterized in that the outer part of the axial flow is divided into several outlet jets distributed around the circumference, which are between partial flows of the partial flow entering the mixing chamber inclined to the axial direction. 4. Burner according to claim 3, characterized in that the exit jets of the enter the outer part of the axial flow inclined to the axial direction into the mixing chamber. Considered publications:
German Patent No. 403 495;
British Patent No. 670,312;
Magazine Archiv für Eisenhüttenwesen, January 1940, pp. 283 to 292: "The mixing processes in gas burners of various types". For this purpose 2 sheets of drawings