DE3021924A1 - Diffusion burner, esp. for tunnel kilns in ceramics industry - uses air of combustion at low pressure, reducing size and cost of air compressors - Google Patents

Abstract

Air of combustion is fed through a side inlet into an outer burner tube(I). Inside tube (I) is a coaxial tube (II) through which fuel gas flows into tube (I); and on the outside of tube (II) are helical blades imparting a swirling motion to the air flowing along tube(I). The outlet end of tube (II) is closed, but near the outlet end are numerous radial outlet holes downstream of the blades. The gas outlet holes in tube (II) are pref. aligned in helical rows, where the helices run in the opposite direction to that of the helical blades. The outer edges of the blades are pref. not in contact with the bore of tube (I). The burner can be operated at higher gas pressures but lower air pressures than conventional burners, so smaller air compressors using less energy can be used to reduce costs. For example, this burner can be operated using a gas pressure of 150-200 mbar with an air pressure of only 26 mbar.

Description

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The invention relates to a diffusion burner, in particular for
Tunnel kilns in the ceramic industry, in which a jacket tube that feeds the combustion air to the interior of the kiln is connected to the
Operating gas acted upon gas pipe is arranged, which at the furnace-side end the operating gas in the via vortex organs between
The combustion air guided by the jacket pipe inner wall and gas pipe surface is released.

Such a diffusion burner is for example in "lecture hall" | 113th year, issue 1/80 on page 38 and discussed in Fig. 8 |

shown on this page. . ' ί

Regardless of whether they are generally designed as swirl disks.

formed vertebral organs on the bf side in front of the burner head or in the ring |

space between the gas pipe and jacket pipe always occurs |

the problem of pressure loss. The swirl fittings should ί

Intensify mixing by making the mixture of gas and air f

whirl. However, every such turbulence means a loss of pressure, ]

which is particularly important when supplying the combustion air |

beats. This pressure loss can be caused by stronger fans | for the combustion air are collected, but mean such

stronger fans higher investment and energy costs, the Γ

ty are not responsible, not least because the maximum I.

Burner power is not always required. j- '

In the case of a large number of different products that are fired in tunnel kilns, for example, and sometimes require very different push times, there is a wide range of settings the burner is necessary. But action in the desire for · Increase power to the limits required for the burner I gas and air flow rates encountered. Optimal furnace utilization often fails
because of the high pressure loss over the burner
the necessary amount of gas and air can be supplied. That already
mentioned way out of a corresponding reinforcement in particular the
Fans for the combustion air supply do not always bring that

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desired success and, in view of the fact, appears inexpedient moderate, that high outputs are not in continuous operation, but in general are only required temporarily.

Another problem is that an increase in the Fans for the combustion air supply does not ultimately lead to success. In the known burner construction is for a certain Setting the gas / air ratio determines the flame pattern or the flame length. A change in the amount of gas means with such burners an adjustment of the air proportion automatically, which in turn means that a readjustment is necessary If you want the performance of an oven with such a burner It cannot be increased sufficiently unless the already mentioned larger fans for the combustion air are installed Bring in air through the burner. So you cannot increase the overrun time of a tunnel kiln, for example, because the required cooking firing temperature is not achievable. But even with the use of larger fans for supplying the combustion air, a performance limit will very soon come up because the main resistance does not appear in the pipe system, but on the burner head itself.

The object of the invention is therefore to develop a gas burner that over a large range of specifications with a justifiable low pressure loss with regard to the supplied combustion air, so the use of stronger Fans for supplying the combustion air can be dispensed with, even with maximum burner performance requirements.

This object is achieved according to the invention in that the gas pipe closed at the oven end and upstream from this end with provided substantially radially discharging gas outlet openings is to the upstream guide vanes extending over a substantial part of their extent essentially parallel to the gas pipe axis connect as vertebral organs.

If the blades on the gas pipe are angled a little across the air flow, then there is a soft, long flame. Will the shovels mind

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sharply bent across the air flow, then there is a short hard flame. .

The guide vanes are expediently on the gas pipe surface put on and bridge the ring space between the gas pipe surface and jacket pipe inner wall only partially. In this way it is possible, without major dismantling work, just to remove the gas pipe with the seated ones Remove the guide vane and replace it with a gas pipe on which differently adjusted guide vanes are arranged.

The gas outlet openings are in a further development of the invention expediently arranged over the circumference of the gas pipe in helically extending rows, the turbulence being further improved by the Coiling of the rows of gas outlet openings in the opposite direction to coiling or bend of the guide vanes can run.

It has been shown that the burner according to the invention compared to a known, working with swirl disc burner with higher gas pressure and lower air pressure can work. The higher gas pressure results without difficulty, v / eil the operating gas generally from a Feed line originates in which it is conveyed with comparatively high pressure. For example, the burner according to the invention operated with a gas pressure of 150 to 200 mbar during operation known burner with an operating pressure of 50 to 100 mbar. In contrast, the air pressure can be reduced to 26 mbar, while the known burners require an air pressure of 40 to 50 mbar. Of the lower air pressure means lower energy costs. The higher gas pressure results automatically from a. less pulling down of the gas pressure compared to the supply pressure in the gas line.

The burner according to the invention can be used both in the oxidation area and can be used in the reduction area.

While in the known burner a change in the amount of gas is automatic influences the amount of air and therefore a post-correction is necessary, this behavior does not appear in the burner according to the invention.

-S-

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The amount of gas and air influence one another in the case of the invention

I burner not, there is no noticeable resistance to combustion air

. ·, Is present in the feeding system. A change in Lu £ = t-

% amount does not affect the amount of gas either, so that

I have better control options for the burner.

The invention thus zdnalit a gas burner which has a large power range with a justifiable low pressure loss dei = i combustion air. With the fuel according to the invention, it is necessary to fully utilize the pressure from the gas supply line which is already present in the gas in order to mix the gas and air. The burner can [■ \ ^ J without difficulty to the respective combustion conditions set

\ i will be. By changing the guide vanes on the gas pipe, i = the

['entire area, starting from a short, sharp flame up to

f a long, soft flame.

As a further advantage it was found with the burner according to the invention,

f ■ that the burner nozzles, in contrast to the known burner nozzles, are not

! coke more so strongly. This reduces operational disruptions,

it results in a lower maintenance effort, the security - «der

k production is increased and finally there is a higher ^ - share

i of first choice goods in production.

I,. Finally, the very simple combustion air supply

* The wear on the metal parts of the burner is significantly reduced compared to the wear that would result from the high air preheating required to save energy. The burner according to the invention also enables longer burner operating times.

The drawing shows an embodiment of a diffusion burner according to the invention in longitudinal section.

The combustion air VL is supplied via a supply pipe 1 to the cartridge pipe in which the gas pipe 3 is arranged, to which the operating gas G is supplied via a supply pipe 4. The gas pipe 3 is arranged over the supply pipe 4 in an extension piece 5, which is screwed

ψ ⁶ 130052/0124

and 7 can be connected to the jacket tube 2. At 8 a sight glass is indicated. The gas pipe is at the oven end 9 closed and, upstream thereof, occupied by rows of gas outlet openings 10, which preferably run in a helix. Upstream of this are seated on the gas pipe 3 guide vanes 11, in the illustrated embodiment, three guide vanes. Over the greater part of their extension, these guide vanes run essentially parallel to the axis 12 of the gas pipe 3 and are angled accordingly at their downstream end. It can be seen that the ιgas pipe: is easily exchangeable ,,, leave -,> Gas pipes with appropriately preselected guide vane types can be used without further ado and thus set the desired flame patterns

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Claims (4)

4S90Hsrno1, SchaefersfralJe 10 1140 Pat. Horrmann-Trenltpohl Telephone: 0 23 23 / S1013 51014 TelegmmmanDohrHt: Bahrpalonte Homo ToIok CS 229 853 ■ ι ι · · · bfpl .'- lng. R. Hf. BahV Dipl.-Phys. Eduard Betzier Dip!. = Irsg. W. Herrmann-Trentepoh! PATENT LAWYERS Buchtal GmbH Ceramic companies
D-8472 Schwarzenfeld BOOO Munich 40, Elsonachcr Straßo 17 P.O. Box 400369 Pnt. Dolzlcr Telephone: 069 / SS 3011 3S3012 36 3013 Telagrummanschrlft: Bahetzpot Münchon Telex £ 215 360 Bank accounts: Bayerische Vereinsbank Munich 952 Dresdner Bank Aß Herne 7-520 Postal check account Dortmund 558 68-467 ^Re <»M 06 875 B / h. Please indicate in the answer Please send a letter to: Collection box 3 DPA June 11, 1980 Diffusion burners, especially for ceramic tunnel ovens Industry. Claims 1 1y diffusion burner, especially for tunnel furnace of the ceramic Industry, in which in a jacket tube that supplies the combustion air to the furnace interior, a gas tube charged with the operating gas is arranged, which at the furnace-side end the operating gas in the via vortex organs between the jacket pipe inner wall and the gas pipe surface discharged combustion air, characterized in that the gas pipe (3) on the furnace side End (9) closed and upstream of this end (9) with im essential radially discharging gas outlet openings (10) provided is, to the upstream extending over a substantial part of its extent essentially parallel to the gas pipe axis (12) Connect guide vanes (11) as vortex organs. 2. Diffusion burner according to claim 1, characterized in that the guide vanes (11) on the gas pipe surface are in place and the ping space between the gas pipe (3) 130052/0124 3Q21924 and casing pipe (2) only partially bridge. 3. Diffusion burner according to claim 1 or 2, characterized-characterized that the gas outlet openings. (10) Across the gas pipe inlet in v / end-shaped rows ajnngeordnol: are. 4. Diffusion burner according to claim 3, characterized in that the twisting of the rows of gas jets ·, openings "(10) j * runs in the opposite direction to the twisting of the guide vanes ('. ^{R J} "' - "* ' ■ "'" ^{ j' ^Tf 130052 / 012A