DE2135840A1 - ADJUSTABLE VENTURAL HEAD FOR CLEANING FURNACE GAS - Google Patents

Description

Professor Dr, -Ing.
Robert M e 1 last

Dipl.-Ing.
Gus.tav M e 1 last
-Pa t en tanwäl t e-

483 Gütersloh Vennstrasse 9

B 1467 Prof. M / d

process technology
Dr.-Ing. Kurt Baum

43 food
Wallotstrasse 4

Adjustable venturi throat for cleaning
of blast furnace gases

Adjustable Venturi throats, which can be used, for example, for cleaning blast furnace gases to adapt to changing gas throughputs
while maintaining a constant pressure loss, it is known that they have long valve flaps with a closing angle of 20-25 and an almost linear control characteristic. With these flaps, a very small angle of rotation changes the throat cross-section considerably.

Such a characteristic is generated when operating at very high speeds, which can rise up to the sound range, unfjigned, because the regulation changes in an unstable range can. Serving area can be opened using known flaps neither avoid nor control. In it the deafness sinks

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degrees down to unusable v / ers.

The new invention solves the problem of a venturi throat with such To create flaps that ensure the necessary sensitive control in the area of the speed of sound. After The invention succeeds in designing flaps in such a way that large angles of rotation change the throat cross-section only slightly. In order to At the same time, the task is solved to regulate the pressure in the sound range quickly and precisely in such a way that a higher pressure loss constantly degraded than that required for gas cleaning will.

With the help of the new flaps, the pressure on the (richt) is also indirectly regulated when used behind blast furnaces.

To solve the problems set, the new Venturi throat is designed such that flaps of a length that approximately half the width of the throat of the Venturi, are used to regulate the throat cross-section of Venturient dusters, which up to operated in the range of the speed of sound.

Another feature are streamlined flaps, their off Pivot vertical edges against each other in a mirror image to form a nozzle curve.

A closing angle of between 60 ° and 90 ° for the Keh-1enklappen is advantageous. _, _

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Another advantage is that the outer edges of the Throat valves to their finite closure position in the manner of a β Roll the roller lock on top of each other.

It is particularly advantageous that the throat flaps are in their rest position form part of the wall of the venturi.

Another improvement is that the length of the throat flaps e.g. adjustable by means of a bayonet guide.

The new invention brings significant technical port steps with it. The increase of the flow in the venturi to the speed of sound increases the degree of dedusting considerably and increases the Size of the separable particles down to the submicroscopic area Smallness. The pressure reduction or the pressure regulating effect is considerable at these high speeds. The effect on the pressure regulation in the gout is corresponding.

The new throat flaps have a very short, compact design as well as a small dwell angle. However, you can can also be designed to be adjustable in length and then, if necessary, subsequently adapt to selectable control tasks.

FIG. 1 explains the basic relationship between flap length and control characteristics;

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FIG. 2 explains the special control characteristics of the new invention.

FIG. 3 compares the control characteristics for different flap lengths. The improvement achieved by the invention is evident.

FIG. 4 is a schematic longitudinal section through, for example, a new throat.

FIG. 5 is a cross-section through a throat valve in the extended state.

FIG. 6 is a cross section corresponding to FIG. 5 with this flap in the pushed together state.

In detail, FIG. 1 is the basic formulaic one Relationship between the length of a control flap of any shape with regard to its control peculiarity according to the following To be taken from derivation.

Derivation of the control characteristic (for any flap length)

sxn S. C. . sin ß sin β max a = C . L. F. = B max = c. B. = a

F 2. c. sin β max. H

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Έ _ν = 2 b. L.

b = a max - a

2b = 2 c. sin β max -2c. sin ß

F = (2 c. Sin ß max - 2 c. Sin β). L /: B

B = 2. c. sin β max

5_x = (V- 2 c. Sin ß ). L B 2 ο. s in ß max

Έ = F (1 - sin ß ^x sin β max

Pure sin ß max = 90

F = F (1 - sin β)

Figure 2 captures this mathematical "relationship" in terms of on the throat flaps in the dimensions according to the invention for the purpose of demonstrating the higher utility value corresponding to the Derivation.

Derivation of the control characteristic (for flap length = 1/2 flute width)

sin ß = a
c

a = c. sin ß = B. L = 2 c. L -2b. L.

■ = c - a

2 b = 2 c - 2 c. s in β

F = (2 c - 2 ο. Hin ß). T,

- 2 ο I, (1 - sin ß) F _x - = F (1 - sin ß)

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Pigiir 3 represents this result in particular for the area high speeds.

In the practical but exemplary embodiment according to Figure 4 is a mirror-image arrangement of short throat valves (1) . can be swiveled into corresponding recesses in a Venturi throat (3) Installed as Venturis (4) in such a way that when the flaps are fully open, the walls (8) of the Venturi throat are flush and smooth continues, and merges into the inner wall of the flaps (7). The flaps are like this in Pig. 4 recognizable, dashed.

The flaps (1) have a length (2) which is approximately half the width corresponds to the throat (4). One also recognizes in Pig. 4 that the flaps (1) are delimited streamlined. Your outer edges (5) pivot in a mirror image of each other, forming a nozzle curve (6). Pig. 4 that the throat flaps (1) have a dwell angle between 6 0 ° and 90 °. In their Vc rfc In the final position, the throat flaps roll from one another in the manner of a roller lock.

The rest of the formation of the Venturi throat corresponds to the usual. A special description can therefore be dispensed with.

The Piguren 5 and 6 each represent oüio on an enlarged scale Throat valve (l) in one opposite dor Fi ^. 4 enlarged version It can be seen that the flaps (1): ', wei to Llig aii.;?>; o-

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are leading. The front ends (5) of the flaps are centered Bayonet guide (9) can be moved lengthways in the rear Pivoting ends stored so that the length (2) can be lengthened or shortened to a considerable extent without affecting the shape or the mechanical strength of the valve is impaired. The longitudinal adjustability of the control flaps can also be done through other means familiar to those skilled in the art can be achieved.

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Claims (6)

Professor Dr.-Ing. · «^ Robert M e 1 d a u * Dipl.-Ing. Gustav M e 1 d a u. -Patentanwälte- B U6? prof # M / d Gütersioh Vennstraße 9 patent claims 1.) Venturi throat, which while maintaining a constant · Pressure loss is adaptable to changing gas throughputs, characterized in that flaps (1) of a length (2), which corresponds approximately to half the width of the throat (3) of the venturi (4), for regulating the throat cross-section of venturi dusters serve, which are operated up to the range of the speed of sound. 2.) Venturi throat according to claim 1, characterized by streamlined Flaps (1), the outer edges (5) of which are mirror images of one another, forming a nozzle curve (6) sway. 3.) Venturi throat according to claims 1 and 2, characterized by a closing angle between 60 ° and 90 ° of the throat flaps (1). 4.) Venturi throat according to claims 1 to 3, characterized in that the outer edges (5) of the throat flaps (1) to '. roll their finite locking position on top of each other like a roller lock (iTig.4). · ν -2- 209886 / 036E 5.) Venturi throat according to claims 1 to 4, characterized in that that the throat flaps (1) in their rest position form part (7) of the wall (8) of the venturi (4). 6.) Venturi throat according to claims 1 to 5, characterized in that that the length (2) of the throat flaps (1) (Fig. 5 and 6) can be adjusted e.g. by means of a bayonet guide (9). 209886 / 036B