JPS58120008A - Burner for solid fuel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a burner with a guide tube for introducing solid fuel into a combustion chamber, in particular a rotary tube furnace.

In rotary furnace burners of this type, the air required for combustion is obtained on the one hand from carrier air, also called primary air, which pneumatically supplies the solid fuel in a cooler connected to the rear of the rotary tube furnace.
On the other hand, it is taken from the heated exhaust air, also called secondary air, of the cooler. This secondary air, for example in a cooler connected after the cement rotary furnace, has a temperature of more than 800'C and cannot be used for pneumatic feeding of solid fuels, especially coal dust, for safety reasons. - Secondary air should be reduced as much as possible for thermoeconomic reasons.

Zement-Kal cast
k-G ips) Magazine (1979 Vol. 32 No. 8 386)
A rotary furnace burner for coal dust is known from pages 1 to 389). It consists of several tubes concentrically inserted into each other, as can be seen in particular from Figure 4, and is composed of air and coal dust, which are dispersed axially or slowly. The mixture leaving the burner is radially surrounded on both sides by streams of pure air. The radially inner air then rotates while the outer air leaves the burner via the axial body or with a slight divergence. In this way, it is possible to influence the flame shape by adjusting the external and/or internal air flow, regardless of the outflow rate of the mixture, which is determined by the pneumatic supply.

If complete and rapid combustion is to be achieved, it is nevertheless a matter of mixing as intensively as possible, on the one hand, the flow of the mixture of secondary air and solid fuel leaving the burner, and, on the other hand, the heated secondary air. Become. This mixing can in principle be achieved by controlling the sufficient swirl of the exiting mixture stream, but with difficulty. This is because there is a limit to the increase in the outflow rate of the mixture. This is because the very long flames in rotary tube furnaces are sensitive to the thermotechnical processes, especially the conditions of the sintering zone and the sintering zone. The lower limit of the outflow rate is determined by the size of the equipment characterizing the pneumatic feed. On the other hand, the demand for changes in the amount of fuel and therefore also heat introduced into the rotary tube furnace is rapid. After all, when using solid fuels as opposed to liquid and gaseous fuels, the heating value and
This is because other parameters that affect the combustion process are expected to vary significantly. It is therefore possible to vary the amount of fuel in the rotary tube furnace and at the same time maintain the conditions necessary for sufficient mixing of the mixture and the subsequent air so that the generated flame remains short, concentrated and hot. is important.

In order to better mix the fuel with the secondary air in the rotary tube furnace, it is conceivable to use rotation on the outflowing coal dust/air mixture. However, it is not satisfactory. This is because the flight distance of coarse coal dust particles is extremely short, and they burn incompletely before hitting the combustion material or the furnace wall. It is therefore an object of the present invention to improve the mixing of the heated secondary air with the flow of the mixture of secondary air and solid fuel, so that the heated secondary air can be brought into contact with the fuel-air mixture as close as possible to the outlet of the burner. It is to put it into the core of.

This object is achieved by the present invention in the following manner.

That is, the cross section of the guide tube and/or at least one other tube extending essentially parallel to this guide tube ends on the combustion chamber side in several outlets. Such an arrangement results in a blending of the flow of the mixture exiting the burner, so that its surface used for absorption of the heated secondary air is determined compared to the embodiment of an arrangement in which only the mixture exits. will be expanded. At the same time, due to the reduced cross-section in the area of the outlet, significantly higher velocities than in the cross-section of the other parts of the guide tube and therefore also vortices occur, so that the conditions for good mixing are decisive. will be improved. The mixing with the heated secondary air and thus also the combustion process is significantly accelerated, so that the short and hot flame required in each case for the combustion process can be prepared. Furthermore, the heated secondary air advantageously reaches the flame core. An embodiment is also conceivable in which the fluid cross section of the tube surrounding the guide tube and supplying the air has a number of outlets on the side of the combustion chamber, so that the mixture can flow out of the steamed rocket jet. The latter is thus surrounded in the region of the inlet by a suction zone consisting of a number of single airs. This suction zone acts like an ejector pump with respect to the heated secondary air.

Due to the strong suction effect, the heated secondary air is thus drawn into the intermediate space between the individual air streams and is intensively mixed with the mixture stream. An embodiment is also contemplated in which the fluid cross section of the guide tube and the surrounding tube has several outlets on the combustion chamber side, so that the best mixing ratio is achieved.

According to an advantageous development of the invention, the outlet is at least partially delimited at the periphery by a stagnation or a similar arrangement arranged inside the guide tube. With such an arrangement, the through-flow cross section of the guide tube is divided into at least two, preferably four, parts. The arrangement of a stagnation filter or similar arrangement is a very simple construction, by means of which the flow of the mixture leaving the burner is divided. The width of the stagnation beam and other built-in bodies is then determined in such a way that the cross-sectional reduction of the outflow area and the speed increase are as desired.

In another embodiment of the invention, the guide tube coaxially surrounds at least one inner tube. In this embodiment, the inner tube is used, for example, to house another burner system, such as an oil or gas burner.

However, it is also conceivable to arrange an ignition burner in this inner tube. After all, the inner tube can also be used to admit rotating air into the combustion chamber so as to influence the shape of the resulting flame. It is also conceivable to provide a number of pipes so that, for example, an oil burner can be provided in this area, and also swirling air can be introduced.

In an advantageous embodiment of the invention, a plurality of tubes are arranged around the periphery of the annular space between the inner tube and the guide tube so that their axes are parallel to the guide tube. Air is very advantageously supplied at high speed by these inner tubes, so that a strong suction effect is created in the area of the inlet of the burner. This suction effect becomes stronger as more tubes are disposed in the ring-shaped space. Coupled with the increased vorticity of the flow of the mixture and the fluid cross section in which the outlet of said tube is located, already delimited by a stagnation beam or similar incorporation, the inlet area of the burner on the one hand produces a heating secondary. An optimal mixing combination of air and, on the other hand, the primary air/fuel mixture is achieved.

Finally, the outlet is provided with mutually independent devices for regulating the flow through. In this way, it is possible to influence not only the number of outlets, but also the amount of flow through each outlet, making it easier to adjust the flame shape. Said device is advantageously a slide valve, the sliding direction being axial and depending on its position opening or closing a large or small flow cross section.

A more detailed explanation will be given based on the drawings showing examples.

In FIGS. 1 and 2, reference numeral 1 is a solid fuel introduction guide pipe, and 2 is a built-in body for the burner population area. The stagnation beam as integral body 2 divides the fluid cross-section of the guide tube 1 into four outlets 2', as can be seen in particular from FIG.

- The fuel supplied by the secondary air flows in the direction indicated by arrow 3 and is divided into four branches depending on the number and arrangement of the stagnation beams. A negative pressure is thus created in the outlet area 4 of the burner, so that the heated secondary air is drawn in in the direction indicated by the arrow 5 and mixes well with the exiting mixture.

In the embodiment shown in FIGS. 3 and 4, the guide tube 1 is surrounded by a jacket tube 6, which itself surrounds an inner tube 7. In the embodiment shown in FIGS.

The jacket tube 6 has an outlet 8 which, as a medium-narrow nozzle, has an axial flow direction and is used for the supply of air. The inner tube 7 serves to accommodate the ignition burner and/or to introduce fuel, for example liquid or gas.

The fuel-air mixture flowing out in the direction indicated by arrow 9 is
Due to the negative pressure generated by the air coming out of the medium-narrow nozzle, the air mixes well with the heated secondary air flowing in the direction shown by the arrow 10.

FIG. 4 shows the exact location and quantity of the outlet 8 and the stagnation beam.

5 and 6 show an embodiment of the burner in which the guide tube 1 surrounds a concentric inner tube 11. FIG. inner tube 11
Inside the ring-shaped space formed by the outer wall of the guide tube 1 and the inner wall of the guide tube 1, there are further tubes 13 distributed uniformly around the circumference and extending in the axial direction of the guide tube 1. Pipe 13 is stagnant 1
4 in its end region directed towards the combustion chamber, its outlet 15 having a medium-narrow nozzle with axial flow in the region of the stagnation beam.

In this embodiment, the tube 13 serves to supply pure air. Pure air flows out from a medium-to-medium nozzle at high velocity.

As a result of the negative pressure created by this, the heated secondary air is
In the direction indicated by 6, the hollow space between the stagnation beams 14 creates a direct suction into the region of the fuel-air mixture exiting from the outlet 17. In this way, the above-mentioned mixture and the secondary air are well combined and mixed, so that all the conditions for rapid combustion are established.

In this embodiment, the inner tube 11 is used to accommodate additional burner systems for other fuels or to provide ignition burners.

7 and 8 show an embodiment of the invention in which the guide tube 1 is provided with two inner tubes 18 and 19 coaxially integrated therein. In this embodiment, the inner tube 19 is provided with an insert 20, which is known per se, between the outer walls of the side tube 19 for ignition of gaseous or liquid fuel. This assembly is shown schematically in the figures, and between the outer wall of the inner tube 19 and the inner wall of the inner tube 18 are bounded a number of outlet openings 18'. In this embodiment, the guide tube 1 is surrounded by a jacket tube 22, which has an annular gap-type outlet 21 with a direction of flow slightly deviated with respect to the longitudinal axis of the guide tube 1. In the end region facing the combustion chamber, this jacket tube has a number of outlets 23, which are particularly visible in FIG. The direction of fluid flow at this outlet is also slightly bent with respect to the longitudinal axis of the guide tube 1, in particular by less than 15°.

In this embodiment, by arranging the inner tube 18 so as to be slidable in the longitudinal direction of the guide tube 1, the speed of the mixture flowing out from the annular gap type outlet 21 can be easily adjusted.

The inner tube 18 and the jacket tube 22 are supplied with air, the amount of which can be adjusted so as to also influence the flame shape and thermodynamic processes occurring in the rotary tube furnace. In this case, since the speed of the air flowing out from the outlet 23 equipped with a nozzle is high, the heated secondary air is sucked in the direction indicated by the arrow 24, and as a result, the fuel-air mixture flowing out from the outlet 21 is mixed with the heated secondary air. Intense mixing with secondary air and therefore also rapid combustion takes place.

In this embodiment, instead of the annular gap type outlet 21, a stagnation or otherwise single cross section is provided for the fuel-air mixture in order to further improve the mixing and suction capacity for the secondary air. It is also a hot idea to be able to provide a cleared outflow cross section on the surface. In the end, the guide tube 1 is the jacket tube 22
In addition, it can also be surrounded by another tube (not shown) which surrounds the jacket tube coaxially or whose axis is parallel to it. For example, additional fuel can be introduced into the combustion chamber by means of such a tube. As a result, a composite burner is required. However, these tubes can also function very advantageously for guiding the coolant.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a burner according to the present invention, FIG. 2 is a side view taken along the line ■-■ in FIG. 1, FIG. 3 is a view showing another embodiment, and FIG. 3 is a side view taken along the line ■-■, FIG. 5 is a diagram showing a further different embodiment, and FIG.
A side view along the line ■-■ in FIG. 5, FIG. 7 is a view of the burner having two inner tubes, and FIG. 8 is a side view taken along the line
■It is a side view along the line. Symbol l in the figure... Guide tube, a'&"8.17.1s; 2
3--- Outlet, 6, 18.22... A tube parallel to the guide tube 1. Agent: Hikaru Esaki Favorable agent: Hikaru Esaki Engraving of Fumi's drawings (no changes to the content) 11 ■ To ■ Nee sequel J Komachi, Ka,) Showa Care Year Academic ability / Te Japan Patent Office Commissioner Haruki Shimada Tono 1 , Indication of the case 1937 Patent Application No. 2″37υ 2, Name of the invention ■Ba2P\charcoal, Sunda/-'2τ- 3. Person making the amendment Relationship to the case Applicant 4, Agent 5. The inventor's office of the application form on the date of the amendment order ← Applicant's column Power of attorney Engraving of the specification. (No change in content) Engraving of drawings. (No change in content)
7. Details of the amendment as shown in the attached sheet.

Claims (1)

[Claims] 1) In a burner having a guide tube for introducing solid fuel into a combustion chamber, in particular a rotary tube furnace, the guide tube (1) and (
or) the combustion chamber side of the flow cross section of at least one tube (6, 18, 22) extending essentially parallel to this guide tube (1) leads to several outlets. 17.18. A burner characterized by ending in '23). 2. In the burner according to claim 1), the peripheral edge of the outlet (2,'2!'17) is at least partially stagnant. A burner characterized in that it is configured to be limited by a similar built-in body. 3) A burner according to claim 1) or 2), in which the guide tube (1) has at least one inner tube (7° 11
, 18.19) coaxially surrounding the burner. 4) In the burner according to claim 1) or 2), several tubes (13) are provided at the periphery of the ring-shaped space (12) between the inner tube (11) and the guide tube (1). A burner characterized in that it is arranged in a distributed manner and that its axis is parallel to the guide tube (1). 5) A burner according to claim 4), characterized in that the pipe (13) has an outlet (15), which outlet is equipped with an axially oriented nozzle, in particular a medium-narrow nozzle. Burner. 6) In the burner according to claim 4), the pipe (13) has an outlet (15), and a nozzle, particularly a medium-thin nozzle, is attached to this outlet, and the flow direction from the medium-thin nozzle is A burner characterized in that it makes an angle θ~200, in particular 150, with respect to the longitudinal axis of the guide tube (1). 7) In the burner according to claim 3), at least the inner tube (18) includes an integrated body (
20). 8) In the burner τ according to any one of claims 1) to 3), the guide tube (1) is disposed inside at least one jacket tube (6, 22) coaxially therewith. A burner characterized by: 9) The burner according to any one of claims 1) to 3), characterized in that the guide tube (1) is surrounded by a plurality of tubes arranged with their axes parallel to each other. burner. 10) Burner according to claim 8), characterized in that the flow cross section of the jacket tube (6, 22) terminates on the combustion chamber side in several outlets (8, 23). 11) In the burner described in claim 10),
A burner characterized in that the outlet (8, 23) is equipped with an axially oriented nozzle, in particular a medium-sized nozzle. 12. In the burner described in claim 10),
The outlet (8, 23) is equipped with a nozzle, especially a medium-thin nozzle, whose flow direction is 0 with respect to the longitudinal axis of the guide tube (1).
A burner characterized in that it has an angle of ~200, especially 150. 13) Any one of claims 1) to 12) is characterized in that in the burner according to -, the outlet (8, 15, 23) has a mutually independent device for adjusting the flow rate. burner.