DE3125429A1 - Device for thorough mixing of gas strands - Google Patents

Abstract

The application relates to a device for thorough mixing of gas strands such as occur, for example, in the combustion chambers of steam generators. According to the invention, the number of blast jets is to be limited in order to achieve an adequate penetration force of the blast jets with the correspondingly greater blowing in. Fig. 3 shows a particularly effective type of blowing-in nozzle which is directed tangentially onto an imaginary circle in the combustion chamber cross-section, the lateral spacing of the blast jets emerging from the nozzle being approximately equal to the combustion chamber depth at the blowing-in point.

Description

Device for mixing strands of gas

The invention relates to a device for mixing the strands of gas in a furnace, in particular in a furnace for steam generation, by blowing in secondary air, back-sucked smoke gases or steam above the Fuel feed.

It is known that the gas strands are mixed by means of secondary air to operate. So far, efforts have been made to arrange as many secondary air nozzles as possible on the assumption that an extensive subdivision of the amount of secondary air is advantageous may be. However, this is not the case, on the contrary, one achieves in this way does not have the desired effect, since the widely divided, i.e. correspondingly small Secondary air volumes do not have the necessary penetration power, and accordingly the entire flue gas flow cannot be mixed sufficiently.

According to the invention it is proposed to have a good penetrating power to achieve the blow jets and to mix the entire flue gas flow, the number of the injection nozzles to a large extent and all or most of the To blow secondary air or also recirculated flue gases or steam into these nozzles, the nozzles on two opposite walls of the furnace laterally against one another are arranged offset so that the lateral distance between the blow jets is approximately is equal to the depth of the combustion chamber at the point of injection.

The invention is explained in more detail in Figures 1-3.

Figure 1 shows the horizontal section through a combustion chamber above the furnace. Injection nozzles 1 and 2 for secondary air, back-sucked flue gas or steam are in opposite walls. The lateral distance 3 of the Nozzles is roughly the same as the depth of the combustion chamber 4. The blowing direction of the nozzles is included directed tangentially to a circle 5 thought to be in the furnace, whereby the A rotary movement is imposed on the entire flue gas flow, which results in a thorough mixing and complete burnout of all the flue gases. When the furnace is out like that arranged in the corners burners is that the focal rays tangentially are directed an imaginary circle in the furnace, it can be useful that the injection of the secondary air is directed in the opposite direction to this last-mentioned circle is.

In the case of grate firing, the combustion chamber is given a better mixing To achieve the smoke gases, often a constriction above the grate by appropriate Bending of the front wall or the rear wall or both of these walls into the combustion chamber into it. Figure 2 shows a section through such a combustion chamber with a Constriction, and Figure 3 shows a horizontal section through the combustion chamber in Height of this constriction. The combustion chamber is above the grate 1 by turning the front wall 2 and the rear wall 3 constricted. In this case, the injection takes place the second air expediently in the area of the constriction at points 4 and 5 on the opposite walls 2 and 3. There the combustion chamber has a depth of 6. The lateral distance 7 of the injection points arranged offset from one another 4 and 5 is approximately equal to the combustion chamber depth 6 at this point. The blowing direction is tangential to the imaginary circles filling the combustion chamber at this point 8th.

Especially with grate firing and large combustion chamber cross-sections, it is ideal Achieving a good firing efficiency is important, but because of the great toughness the hot flue gases difficult to mix the gases well all over To achieve combustion chamber cross-section. The above invention provides an advantageous one for this Solution.

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Claims (5)

Claims 1. / device for mixing the strands of gas in combustion chambers, in particular in the combustion chambers of steam generators, by blowing in secondary air, steam or back-sucked flue gases above the fuel feed, characterized in that the number of the secondary air, steam or flue gases injecting nozzles is limited in such a way that the lateral distance of the out The jets exiting the nozzles are approximately equal to the depth of the combustion chamber at the injection point is. 2. Device according to claim 1, characterized in that the injection nozzles are arranged on two opposite walls of the combustion chamber. 3. Device according to claim 1 or 2, characterized in that the injection nozzles are arranged in a combustion chamber constriction. 4. Device according to claim 1, 2 or 3, characterized in that that the blowing direction of the injection nozzles is tangential to one in the combustion chamber cross-section imaginary circle is directed. 5. Device according to claim 1, 2, 3 or 4, characterized in that that with burner firing the secondary air, steam or flue gases in reverse Sense of injecting fuel is injected.