EP2522903A2 - Air nozzle for introducing a gas flow comprising an oxidation agent into a combustion chamber - Google Patents

Abstract

The air nozzle (1) has a finger nozzle (2) having a gas feed (3) and a gas flow design structure (4). A nozzle cap (7) is provided for covering finger nozzle at region of gas flow design structure. A discharging hole is provided in the outer nozzle casing for discharging the gas stream. The finger nozzle and nozzle cap can be detachably attached by non-threaded clamp connection. The discharging hole is in fluid communication with gas flow design structure when finger nozzle and nozzle cap are interconnected. An independent claim is included for method for assembling air nozzle.

Description

The subject matter of the present invention is an air nozzle for introducing a gas stream comprising an oxidizing agent, in particular air, into a combustion chamber, which can be used in particular for introducing an oxygen-containing gas stream into a fluidized-bed furnace.

In the operation of a fluidized bed combustion, it is necessary to introduce a gas stream as fluidizing medium into the furnace, which is used together with a support medium such as sand and a granular fuel, such as lignite, to form a fluidized bed. At the same time, when introducing air, the oxygen contained therein is used as the oxidizing agent in the furnace. The air serves as a fluidizing medium, by which the fuel to be burned and the support material such as sand held in suspension and thus fluidized. Depending on the size of the combustion chamber, a very large number of air nozzles can be used, for example more than 1,500 air nozzles per combustion chamber. Due to the high temperatures present in the combustion chamber and due to possible abrasive effects due to the bed material and / or the fuel in contact with the air nozzles, these are subject to a large seal and the risk of deformation. Consequently, these air nozzles must be replaced regularly.

The air nozzles protrude into the combustion chamber and are each connected to a flow pipe, through which the fluidization medium is supplied. The inflow pipes are usually passed through a refractory layer such as a suitably trained concrete or fireclay wall. For a simple exchange To allow the air nozzles, it is known from the prior art such as from the DE 40 38 341 C1 known to form a two-part nozzle, wherein the two parts of the nozzle are connected to one another via a thread. Thus, at least theoretically, replacement of the air nozzles is possible. However, it has been shown that the individual nozzle parts caked together by the continuous operation at high temperatures. As a result, the two parts are difficult to detach from each other, often it comes in the solution attempt to damage the flow pipe. This leads to a greatly increased effort when changing the air nozzles, in the extreme case, it is necessary to at least partially remove the refractory layer surrounding the Anströmrohre to replace or repair the Anströmrohre.

Proceeding from this, the present invention has the object, at least partially overcome the known from the prior art disadvantages and in particular to provide an air nozzle, which is easy to replace, for example, for several years of use, without causing damage to the flow pipes.

This object is achieved by an air nozzle with the features of the independent claim. The dependent claims are directed to advantageous developments.

The features listed individually in the claims can be combined with each other in any technologically meaningful manner and can be supplemented by explanatory facts from the description, with further embodiments of the invention being shown.

• einen Düsenfinger mit mindestens einer Gasstromzuführung und mindestens einer Gasstromausführung;
• eine Düsenhaube zum Überdecken des Düsenfingers zumindest im Bereich der mindestens einen Gasstromausführung mit mindestens einem Loch in der Außenhülle zum Ausleiten des Gasstroms,

wobei Düsenfinger und Düsenhaube durch eine gewindefreie Klemmverbindung lösbar miteinander verbindbar sind, wobei das mindestens eine Loch mit der mindestens einen Gasstromausführung in strömungstechnischer Verbindung steht, wenn Düsenfinger und Düsenhaube miteinander verbunden sind.The air nozzle according to the invention for introducing a gas stream comprising an oxidizing agent into a combustion chamber comprises:

• a nozzle finger with at least one gas flow supply and at least one gas flow design;
• a nozzle hood for covering the nozzle finger, at least in the region of the at least one gas flow embodiment with at least one hole in the outer shell for discharging the gas flow,

wherein nozzle fingers and nozzle hood are detachably connectable to each other by a thread-free clamping connection, wherein the at least one hole with the at least one gas flow design is in fluid communication, when nozzle fingers and nozzle hood are connected together.

The gas stream comprising an oxidizing agent is understood in particular to mean air or oxygen-enriched air or oxygen. The nozzle finger is designed so that the gas flow supply can be connected to the flow pipe. The at least one gas flow embodiment is preferably formed at right angles to the gas flow supply and is formed in particular in a lateral surface of the nozzle finger. The nozzle hood preferably has a plurality of holes formed in a lateral surface of the nozzle hood for discharging the gas flow into the combustion chamber.

Preferably, the nozzle finger has a substantially cylindrical geometry, wherein a gas flow supply is formed in an end face of the cylinder, while one or preferably a plurality of gas flow designs are formed in the lateral surface of the cylinder. In principle, an embodiment is preferred in which the gas flow designs are distributed over the radius of the lateral surface and, in particular, are distributed radially uniformly over the lateral surface. Also, the nozzle cap preferably has a substantially cylindrical geometry, wherein the cylinder is closed at one end and the other end is formed so that the nozzle finger can be inserted therethrough in the nozzle hood and then connected to the nozzle finger. The holes for the exit the gas stream are preferably formed in the lateral surface of this cylinder.

Under a thread-free clamping connection is understood in particular that no screw or threaded connection between the nozzle hood and the nozzle fingers is formed, so no connection in which on a screw or helical line, which includes a solid angle of more than 360 °, made a frictional connection between two elements becomes. Rather, it is preferably a compound in which come by twisting the nozzle cover relative to the nozzle finger by an angle of significantly less than 360 °, especially less than 180 °, more preferably less than 90 ° clamping elements on the nozzle finger and nozzle hood in frictional engagement , A preferred embodiment is a bayonet closure.

According to an advantageous embodiment of the air nozzle according to the invention, the clamping connection is formed by rotating two elements, in particular two at least partially annular elements, on the nozzle finger and nozzle hood against each other.

The elements are also referred to as first connection means in the case of the nozzle finger and as second connection means in the case of the nozzle hood. The preparation of the clamping connection by simply rotating preferably by a predetermined angular range such as 90 ° or less allows easy release of the nozzle hood and nozzle fingers and possibly also an exchange alone the nozzle hood with a retention of the nozzle finger. This simple disassembly and assembly is possible even under difficult conditions, for example, using work gloves and the like. Even after prolonged operation of such air nozzles, there is no caking, that is, to form a cohesive connection between the nozzle hood and nozzle fingers, which also after prolonged use allows easy release of nozzle hood and nozzle fingers without damaging the flow tube.

According to a further advantageous embodiment of the air nozzle according to the invention nozzle fingers and nozzle hood are designed so that the nozzle hood surrounds the nozzle finger in the connected state of a base plate on the outside in a longitudinal direction.

This means, in particular, that the nozzle finger has a base plate against which the nozzle hood rests or in the vicinity of which the nozzle hood ends. Basically, the base plate is to be understood as meaning a plane from which the nozzle hood surrounds the nozzle finger in the longitudinal direction on the outside in the longitudinal direction. The base plate can serve to form a connection with a flow pipe or with an annular disc.

According to a further advantageous embodiment of the air nozzle according to the invention, the nozzle finger on a first connection means for producing the unthreaded clamping connection, which extends from the base plate in the longitudinal direction while the nozzle cover has a corresponding second connection means which is suitable and intended for receiving the first connection means.

This embodiment makes it possible to realize improved protection against penetrating granular material such as the carrier medium. The formation of the clamping connection can thereby be laid in a plane which is spaced in the longitudinal direction of the base plate, so that the connection between the nozzle hood and nozzle fingers is denser gestaltbar than in a formation of the clamping connection in the plane of the base plate or in their immediate vicinity. Depending on the process parameters in fluidized bed control, this can be advantageous, especially when using a very small granular carrier medium.

According to an advantageous embodiment of the air nozzle according to the invention, this is formed of a cast steel, preferably austenitic cast steel.

The formation of a thread-free connection between the nozzle finger and nozzle hood makes it possible for the first time to dispense with a machining production of nozzle hood and nozzle fingers. This makes it possible, in particular, to produce holes and / or gas flow designs whose cross section changes. By using cast steel and preferably austenitic cast steel, an air nozzle can be produced which is resistant to high temperatures and can be disassembled into its component parts even after prolonged use without the risk of damaging the flow pipe in particular.

• 53,43 bis 63,7 Gew.-% [Gewichts-%] Eisen (Fe);
• 0,3 bis 0,5 Gew.-% Kohlenstoff (C);
• bis zu 2,0 Gew.-% Mangan (Mn);
• bis zu 0,04 Gew.-% Phosphor (P);
• bis zu 0,03 Gew.-% Schwefel (S);
• 24 bis 2 7 Gew.-% Chrom (Cr);
• bis zu 0,5 Gew.-% Molybdän (Mo); und
• 11 bis 14 Gew.-% Nickel (Ni).

According to a further advantageous embodiment of the air nozzle according to the invention, this is formed from a material comprising the following substances:

• 53.43 to 63.7% by weight [weight%] iron (Fe);
• 0.3 to 0.5% by weight of carbon (C);
• up to 2.0% by weight of manganese (Mn);
• up to 0.04 wt% phosphorus (P);
• up to 0.03% by weight of sulfur (S);
• 24 to 27% by weight of chromium (Cr);
• up to 0.5% by weight of molybdenum (Mo); and
• 11 to 14 wt .-% nickel (Ni).

In particular, a material can be used, which is sold under the material number 1.4828 or 1.4837 steel key.

• Weniger als 0,2 Gew.-% Eisen (Fe);
• 1,5 bis 2,5 Gew.-% Silicium (Si);
• Weniger als 2,0 Gew.-% Mangan (Mn);
• Weniger als 0,045 Gew.-% Phosphor (P);
• Weniger als 0,015 Gew.-% Schwefel (S);
• 19,0 bis 21,0 Gew.-% Chrom (Cr);
• 11,0 bis 13,0 Gew.-% Nickel (Ni);
• Weniger als 0,11 Gew.-% Stickstoff; und
• Rest Eisen (Fe).

Alternatively, the air nozzle according to the invention may be formed from a material comprising the following substances:

• Less than 0.2% by weight of iron (Fe);
• 1.5 to 2.5% by weight of silicon (Si);
• Less than 2.0% by weight of manganese (Mn);
• Less than 0.045 wt% phosphorus (P);
• Less than 0.015% by weight of sulfur (S);
• 19.0 to 21.0 wt% chromium (Cr);
• 11.0 to 13.0 wt% nickel (Ni);
• Less than 0.11% by weight of nitrogen; and
• Remainder iron (Fe).

Such a material has been found to be particularly heat resistant even at high temperatures.

• eine Zugfestigkeit (Rm) von mindestens 450 N/mm² [Newton pro Quadratmillimeter] bei einer Temperatur von 20°C [Grad Celsius]
• eine 0,2%-Dehngrenze (Rp0,2) von mindestens 220 N/mm² bei einer Temperatur von 20°C;
• eine Bruchdehnung (A10) von mindestens 6 % bei einer Temperatur von 20°C;
• eine Brucheinschnürung (Z) von mindestens 10 % bei einer Temperatur von 20°C;
• eine Brinellhärte von höchstens 250 HB bei einer Temperatur von 20°C;
• eine Wärmeleitfähigkeit von mindestens 10 W/(m K) [Watt pro Meter und Kelvin) bei einer Temperatur von 20°C;
• eine spezifische Wärmekapazität von mindestens 480 J/(kg K) [Joule pro Kilogramm und Kelvin] bei einer Temperatur von 20°C; und
• einen Längenausdehnungskoeffizienten von mindestens 15 10^-6 K^-1 [10-6 pro Kelvin] bei einer Temperatur von 400°C.

According to a further embodiment of the air nozzle, this is made of a material which has at least one of the following properties:

• a tensile strength (Rm) of at least 450 N / mm ² [Newton per square millimeter] at a temperature of 20 ° C [degrees Celsius]
• a 0.2% proof stress (Rp0.2) of at least 220 N / mm ² at a temperature of 20 ° C;
• an elongation at break (A10) of at least 6% at a temperature of 20 ° C;
• a fracture contraction (Z) of at least 10% at a temperature of 20 ° C;
• a Brinell hardness of at most 250 HB at a temperature of 20 ° C;
• a thermal conductivity of at least 10 W / (m K) [watts per meter and Kelvin) at a temperature of 20 ° C;
• a specific heat capacity of at least 480 J / (kg K) [joules per kilogram and Kelvin] at a temperature of 20 ° C; and
• a coefficient of linear expansion of at least 15 10 ^-6 K ^-1 [10-6 per Kelvin] at a temperature of 400 ° C.

In particular, the tensile strength, the 0.2% proof stress, the elongation at break, the thermal conductivity, the specific heat capacity and the expansion coefficient are determined in accordance with EN10295.

Preferred is an embodiment in which the nozzle fingers and / or nozzle hood are made of the material 1.4837 or 1.4828 after the steel key. Alternatively, the nozzle fingers and / or nozzle hood can also be formed from at least one of the following materials: 1.4841 after the steel key and / or 2.4816 after the steel key.

1. a) mindestens eine Gasstromausführung; und
2. b) mindestens ein Loch zum Ausleiten des Gasstroms

einen durchströmbaren Querschnitt auf, der sich über die Länge der Gasstromausführung ändert.According to a further embodiment of the air nozzle according to the invention, at least one of the following elements comprises:

1. a) at least one gas flow design; and
2. b) at least one hole for discharging the gas flow

a flow-through cross-section, which varies over the length of the gas flow design.

By varying the cross-section over the length of the gas flow design, that is, over the thickness of the material from which the nozzle finger and / or the nozzle hood is formed, it can be achieved that the gas flow when passing through the gas flow design and / or the hole for discharging assumes fluidic properties. Thus, the flow direction, the flow distribution, the flow velocity and also the type of flow can be controlled, for example with regard to a possible turbulence in the flow. It is thus possible to design the nozzle fingers and nozzle hood so that certain gas flows are produced in the furnace. Thus, it is possible to use distributed over a firebox differently shaped air nozzles, so as to achieve optimal fluidization in the furnace. Furthermore, it is possible to make the gas flow designs and / or the holes for discharging so that the least possible wear occurs in the nozzle.

1. a) mindestens eine Gasstromausführung und
2. b) mindestens ein Loch zum Ausleiten des Gasstroms

von innen nach außen.According to a further embodiment of the air nozzle according to the invention, at least one of the following elements tapers:

1. a) at least one gas flow design and
2. b) at least one hole for discharging the gas flow

from the inside to the outside.

Thus, there is acceleration of the gas flow when passing through the gas flow design in the nozzle finger and / or the hole for discharging the gas flow in the nozzle hood. Thus, improved fluidization properties of the gas flow can be achieved.

1. a) mindestens eine Gasstromausführung und
2. b) mindestens ein Loch zum Ausleiten des Gasstroms

innenseitig eine Aufweitung auf, wobei die Aufweitung zumindest teilweise durch einen Kreisbogen beschrieben werden kann.According to a further embodiment of the air nozzle according to the invention, at least one of the following elements comprises:

1. a) at least one gas flow design and
2. b) at least one hole for discharging the gas flow

an expansion on the inside, wherein the expansion can be described at least partially by a circular arc.

So it is possible to expand the gas flow design and / or the hole for discharging the gas flow on the inside and to describe this expansion by a radius. This leads to improved flow properties, which can be calculated and produced in a simple manner hydrodynamically. Furthermore, an air nozzle produced in this way has a significantly higher wear resistance.

According to a further embodiment of the air nozzle according to the invention, this comprises an annular disc for connection to a flow pipe and the gas flow supply of the nozzle finger, wherein the inner diameter of the annular disc substantially corresponds to the outer diameter of the flow pipe and the outer diameter of the annular disk is greater than an outer diameter of the gas stream supply.

The use of an annular disc offers significant advantages over the known from the prior art solutions. In solutions known from the prior art, a nozzle finger is welded directly from the outside to the flow pipe, so this extends into the gas flow supply of the nozzle finger. With repeated replacement of the corresponding nozzle finger, this regularly leads to thickening of the material in the interior of the inflow pipe, which reduces the flow-through cross section of the inflow pipe and has a negative effect on the flow properties, in particular on the Reynolds number of the flow in the inflow pipe. The use of a corresponding annular disc according to the embodiment of the present invention is advantageous because the corresponding annular disc from the outside of the flow pipe - for example, selectively - can be welded without causing a reduction in the flow-through cross-section of the flow pipe. Furthermore, the use of an annular disc allows easier disassembly of the nozzle finger, without causing damage to the flow pipe. The annular disc itself can be connected in a simple manner with the gas flow supply, preferably cohesively, for example by punctiform or linear welding.

• a. eine Ringscheibe stoffschlüssig mit einem Anströmrohr verbunden wird;
• b. ein Düsenfinger stoffschlüssig mit der Ringscheibe verbunden wird; und
• c. eine Düsenhaube kraftschlüssig über eine Klemmverbindung mit dem Düsenfinger verbunden wird.

According to a further aspect of the present invention, a method for assembling an air nozzle according to the present invention is proposed in which

• a. an annular disc is materially connected to a flow pipe;
• b. a nozzle finger is materially connected to the annular disc; and
• c. a nozzle hood is non-positively connected via a clamping connection with the nozzle finger.

The inventive method allows in a simple manner, the replacement of closures on air nozzles, especially in fireboxes in a fluidized bed combustion. The air nozzles can preferably be used to form a fluidized layer, in which a gas stream comprising an oxidant, such as air, is introduced through the air nozzle into the furnace and used there for fluidization as fluidizing medium.

Fig. 1:

eine seitliche geschnittene Ansicht einer ersten Ausführungsform einer erfindungsgemäßen Luftdüse;

Fig. 2:

eine erfindungsgemäße Luftdüse im Querschnitt;

Fig. 3:

einen Düsenfinger einer erfindungsgemäßen Luftdüse im Längsschnitt;

Fig. 4:

einen Düsenfinger einer erfindungsgemäßen Luftdüse im Querschnitt;

Fig. 5:

eine Düsenhaube einer erfindungsgemäßen Luftdüse im Längsschnitt,

Fig. 6:

eine Düsenhaube einer erfindungsgemäßen Luftdüse im Querschnitt;

Fig. 7:

eine perspektivische Ansicht eines Düsenfingers einer erfindungsgemäßen Luftdüse;

Fig.8:

eine perspektivische Ansicht einer Düsenhaube einer erfindungsgemäßen Luftdüse;

Fig. 9:

eine Ansicht des Verbindungsbereichs einer Düsenhaube einer erfindungsgemäßen Luftdüse im Querschnitt;

Fig. 10:

eine Ansicht des Verbindungsbereichs eines Düsenfingers einer erfindungsgemäßen Luftdüse;

Fig. 11:

eine Ansicht einer Ringscheibe einer Fortbildung der erfindungsgemäßen Luftdüse im Querschnitt im montierten Zustand;

Fig. 12:

eine Schnittansicht eines Düsenfingers einer erfindungsgemäßen Luftdüse im montierten Zustand;

Fig. 13:

eine schematische Ansicht eines Details eines Düsenfingers oder einer Düsenhaube;

Fig. 14:

eine perspektivische Ansicht eines Düsenfingers einer zweiten Ausgestaltung der erfindungsgemäßen Luftdüse

Fig. 15:

den Düsenfinger der zweiten Ausgestaltung der erfindungsgemäßen Luftdüse in einem Längsschnitt;

Fig. 16:

den Düsenfinger der zweiten Ausgestaltung der erfindungsgemäßen Luftdüse in einem Querschnitt;

Fig. 17:

eine Düsenhaube der zweiten Ausgestaltung der erfindungsgemäßen Luftdüse in einem Längsschnitt; und

Fig. 18:

die Düsenhaube der zweiten Ausgestaltung der erfindungsgemäßen Luftdüse in einem Querschnitt.

The details and advantages disclosed for the air nozzle according to the invention can be transferred and applied to the method according to the invention and vice versa. The invention and the technical environment of the invention will be explained in more detail with reference to FIGS. The figures show particularly preferred embodiments, to which the invention is not limited. In particular, it should be noted that the figures are exemplary and in particular the proportions shown are only schematically. Show it:

Fig. 1:

a side sectional view of a first embodiment of an air nozzle according to the invention;

Fig. 2:

an air nozzle according to the invention in cross section;

3:

a nozzle finger of an air nozzle according to the invention in longitudinal section;

4:

a nozzle finger of an air nozzle according to the invention in cross section;

Fig. 5:

a nozzle hood of an air nozzle according to the invention in longitudinal section,

Fig. 6:

a nozzle hood of an air nozzle according to the invention in cross section;

Fig. 7:

a perspective view of a nozzle finger of an air nozzle according to the invention;

Figure 8:

a perspective view of a nozzle hood of an air nozzle according to the invention;

Fig. 9:

a view of the connecting portion of a nozzle hood of an air nozzle according to the invention in cross section;

Fig. 10:

a view of the connecting portion of a nozzle finger of an air nozzle according to the invention;

Fig. 11:

a view of an annular disc of a development of the air nozzle according to the invention in cross section in the assembled state;

Fig. 12:

a sectional view of a nozzle finger of an air nozzle according to the invention in the assembled state;

Fig. 13:

a schematic view of a detail of a nozzle finger or a nozzle hood;

Fig. 14:

a perspective view of a nozzle finger of a second embodiment of the air nozzle according to the invention

Fig. 15:

the nozzle finger of the second embodiment of the air nozzle according to the invention in a longitudinal section;

Fig. 16:

the nozzle finger of the second embodiment of the air nozzle according to the invention in a cross section;

Fig. 17:

a nozzle hood of the second embodiment of the air nozzle according to the invention in a longitudinal section; and

Fig. 18:

the nozzle hood of the second embodiment of the air nozzle according to the invention in a cross section.

Fig. 1 schematically shows a sectional view of an air nozzle according to the invention 1. The air nozzle 1 is used in particular for introducing an air flow into a furnace with a fluidized bed combustion. The air nozzle 1 comprises a nozzle finger 2. This has a gas flow supply 3 and a plurality of gas flow designs 4. The nozzle finger 2 has a substantially cylindrical geometry with a lateral surface 5. The gas flow versions 4 are designed as holes through the lateral surface 5 of the nozzle finger 2. The gas flow supply 3 is designed through a hole in one of the end faces 6 of the nozzle finger 2.

The nozzle finger 2 is covered by a nozzle hood 7. Nozzle fingers 2 and nozzle hood 7 are detachably connected together by a thread-free clamping connection, with reference to Fig. 2 will be explained in more detail. Fig. 2 schematically shows a section through the corresponding in Fig. 1 designated place. The nozzle finger 2 in this case has first connection means 8, which are brought into frictional connection with second connection means 9 of the nozzle hood 7. For this purpose, the nozzle hood 7 is slipped over the nozzle finger 2. By turning against each other, the second connecting means 9 above or below the first connecting means. 8 pushed until a traction is achieved. Here, first connecting means 8 and second connecting means 9 do not form a thread, ie the connection is a thread-free clamping connection. First connecting means 8 and second connecting means 9 preferably represent substantially planar elements, of which at least one is slightly beveled, so that when twisting against each other, the formation of the frictional connection occurs. Preferably, first connecting means 8 and second connecting means 9 are designed so that they are in the longitudinal direction 10 (see Fig. 1 ) have a thickness of at least 1 mm, preferably of at least 2 or even at least 4 mm. Thus, a stable, detachable connection can be formed, the

Fig. 3 schematically shows a longitudinal section through a nozzle finger 2. Perpendicular to the longitudinal direction 10, the nozzle finger 2 gas flow versions 4. These are formed in the lateral surface 5 of the nozzle finger 2. In addition to the first connecting means 8, sealing means 11 are formed. In the present embodiment, this is a corresponding projection in the state connected to the nozzle hood 7 (see. Fig. 1 ) to a seal of the space between the nozzle hood 7 and nozzle fingers 2 causes. In particular, the penetration of fluidizing medium can be effectively reduced.

In particular, when sand is used as the fluidizing medium, this significantly increases the wear resistance of the nozzle finger 2 and nozzle hood 7. Further shows Fig. 3 an annular base plate 12, by means of which the nozzle finger 2 is connectable to a corresponding circular ring. This is further below with particular reference to FIGS. 11 and 12 explained in more detail. The distance in the longitudinal direction 10 between the first connecting means 8 and the gas flow designs 4 can be varied depending on the properties of the fluidized bed to prevent the penetration of sand through the nozzle hood 7 and the gas flow designs 10 in the gas flow supply 3. The gas flow versions 4 are formed in this embodiment in several rows in the longitudinal direction 10 one above the other.

Fig. 4 schematically shows the in Fig. 3 It can be seen, inter alia, that the gas flow versions 4 (which are provided here for clarity, as well as in the other figures only in part with reference numerals) are widened inside. For more details will be on Fig. 13 referenced below. Evident are also the first connecting means 8, the sealing means 11 and the base plate 12th

Fig. 5 schematically shows a longitudinal section of a nozzle hood 7, Fig. 6 schematically the in Fig. 5 with VI marked cross section through the nozzle hood 7. This has an outer shell 13 with a plurality of holes 14 for discharging the gas flow in the furnace. Also, the holes 14 for discharging the gas flow, which are connected in the connected to the nozzle finger 2 state with the at least one gas flow design 4 in fluid communication, taper from the inside to the outside, so are expanded in the interior. The nozzle hood 7 furthermore has an opening 15 which, unlike the holes 14, is not formed in the lateral surface 13 but in an end face of the nozzle hood 7. The opening 15 serves to insert the nozzle finger 2 during assembly of the nozzle hood 7 and nozzle fingers 2.

Furthermore, the second connection means 9 are provided for connection to the corresponding first connection means 8 of the nozzle finger 2.

Fig. 7 schematically shows a perspective view of a nozzle finger 2. In the lateral surface 5, the gas flow versions 4 are formed over the circumference of the substantially cylindrical nozzle finger 2 evenly distributed in two übereinaderliegende rows. On a frontal surface of the nozzle finger 2, the gas flow supply 3 limiting base plate 12 is formed. Between the gas flow versions 4 and the sock plate 12, the sealing means 11 and the first connecting means 8 are formed. In operation, the stream of gas comprising an oxidant flows through the gas stream feed 3 into the nozzle finger 2 and flows out of the nozzle finger 2 into the space between the nozzle finger 2 and the nozzle cap 7 through the gas stream executions 4.

Fig. 8 schematically shows a perspective view of a nozzle hood 7. With the opening 15, the nozzle hood 7 is slipped over the nozzle finger 2, by a frictional connection between the second connecting means 9 of the nozzle hood 7 and the first connecting means 8 of the nozzle finger 2 is a frictional connection of nozzle hood 7 and Nozzle finger 2. The gas stream comprising an oxidizing agent, preferably air or oxygen-enriched air, flows through the gas stream feed 3 into the nozzle finger 2 during operation and leaves it through the gas stream designs 4. The gas stream then leaves the nozzle cap 7 through the holes 14. Furthermore, FIG the nozzle cover 7 tool engagement 16 on. At these a tool, for. As a key, are recognized, with which the positive connection between the nozzle hood 7 and nozzle fingers 2 can be made and released again. This can be done in a simple manner, especially in air nozzles 1, which have already been in use for a certain amount of time, in the case of methods known from the prior art, a high personnel and effort is required to loosen the threaded connection. The air nozzle 1 according to the invention represents a significant improvement in this respect, which significantly reduces the cost and material costs for maintenance and replacement of the air nozzles 1. Further shows Fig. 8 a further sealing means 11 which is intended to prevent the penetration of carrier medium into the nozzle finger 2.

Fig. 9 schematically shows the nozzle hood 7. In the interior, the nozzle hood 7, the second connecting means 9.

Fig. 10 shows the corresponding cross section through the nozzle finger 2. This has from bottom to top, the base plate 12, the sealing means 11 and the first connecting means 8. To produce the detachable connection between the nozzle hood 7 and nozzle fingers 2, the first connecting means 8 and the second connecting means 9 of the nozzle hood 7 are superimposed and then rotated against each other, so that there is a frictional connection between the first connecting means 8 and second connecting means 9 and thus between the nozzle fingers 2 and Nozzle hood 7 is formed.

Fig. 11 schematically shows an annular disc 17. This annular disc 17 has an inner diameter 18. The annular disc 17 is formed around a flow pipe 19 around. The inner diameter 18 of the annular disc 17 corresponds substantially to an outer diameter 20 of the Anströmrohrs 19. The annular disc 17 is in particular designed so that it can easily put on corresponding flow pipes 19, so that the flow pipe 19 is formed within the annular disc 17, but a minimum distance between the annular disc 17 and the flow tube 19 remains. Then, the formation of a cohesive connection between the annular disc 17 and the flow pipe 19 can take place, preferably by welding. Furthermore, the annular disc 17 has an outer diameter 21 which is larger than a corresponding outer diameter of the base plate 12 of the nozzle finger 2, so that in a simple manner a cohesive connection between the nozzle finger 2 and annular disc 17 can be formed.

This is especially true Fig. 12 clearly, which schematically shows a nozzle finger 2 in the installed state. With the base plate 12 of the nozzle finger 2 is integrally connected to the annular disc 17. This is formed at the upper end of a Anströmrohrs 19, which extends through a heat-resistant cladding 22 therethrough. The base plate 12 is integrally connected and in particular by welding with the annular disc 17. Another possibility of an embodiment according to the invention provides that the inflow pipe protrudes from the heat-resistant lining 22 for a certain amount, that is, there is a distance between the lower edge of the annular disc 17 and the surface of the heat-resistant lining 22.

Fig. 13 schematically illustrates a possibility of the course of the gas flow design 4 and the holes 14. These each extend from an inner side 23 to an outer side 24. Wie Fig. 13 shows, the gas flow version 4 or the hole 14 on the inside a widening 25. The gas flow version 4 and / or the hole 14 thus taper from the inside to the outside. The widening 25 is designed so that it can be described by a circular arc with a radius 26.

Fig. 14 schematically shows a nozzle finger 2 of a second embodiment of an air nozzle 1 according to the invention. Here, only the differences between the two embodiments will be described, for the rest, reference is made to the description of the first embodiment. In contrast to the nozzle finger 2, in the first embodiment of an air nozzle 1 according to the invention, the nozzle finger 2 in the second embodiment has first connection means 8 with clamping region 27 which extend from the base plate 12 of the nozzle finger 2 in the longitudinal direction 10. The longitudinal direction 10 is defined so that it points from the base plate 12 in the direction which is covered by the nozzle hood 7 in the connected state. Thereby, the plane in which the thread-free clamping connection between the nozzle finger 2 and the nozzle hood 7 is formed, from the plane of the base plate 12th relocated away. Thus, an increased density of the air nozzle 1 against the ingress of dust can be achieved.

Fig. 15 shows a corresponding longitudinal section of the nozzle finger 2. As in the FIGS. 14 and 15 to see, both oppositely formed first connecting means 8 a clamping portion 27, via which a thread-free clamping connection with the second connecting means 9 of the corresponding nozzle hood 7 can be formed. FIGS. 15 and 16 schematically show a longitudinal section and a cross section through the nozzle finger. 2

The FIGS. 17 and 18 schematically show the corresponding nozzle hood 7 of the second embodiment of the air nozzle according to the invention 1. The nozzle hood 7 has two second connecting means 9, which are each designed as an L-shaped slot. Here, the L is adapted in its contour to the contour of the nozzle hood 7, such as Fig. 18 shows. The narrow leg of the L-shaped slot of the second connecting means 9 is formed as a clamping region 27. In cooperation with the clamping region 27 of the first connecting means 8 of the nozzle finger 2 so a thread-free clamping connection between the nozzle finger 2 and nozzle hood 7 is formed.

The air nozzle 1 according to the invention advantageously makes it possible, with good fluidic properties and low wear, to introduce air as a gas stream comprising an oxidizing agent into a combustion chamber, in particular a fluidized bed furnace. At the same time, the nozzle hood 7 can be easily reversibly separated from the nozzle finger 2, the air nozzles 1 can be so easily inspected, maintained and replaced.

LIST OF REFERENCE NUMBERS

1

air nozzle

2

nozzles finger

3

Gas power supply

4

Gas power away

5

lateral surface

6

face

7

nozzle hood

8th

first connection means

9

second connection means

10

longitudinal direction

11

sealant

12

plinth

13

outer shell

14

Hole for discharging the gas flow

15

opening

16

tool engagement

17

washer

18

Inner diameter annular disc

19

inflow tube

20

Outer diameter of flow pipe

21

Outer diameter washer

22

heat resistant cladding

23

inside

24

outside

25

widening

26

radius

27

clamping range

Claims (10)

An air nozzle (1) for introducing a stream of gas comprising an oxidant into a furnace, comprising: - A nozzle finger (2) with at least one gas stream supply (3) and at least one gas flow design (4); - A nozzle hood (7) for covering the nozzle finger (2) at least in the region of at least one gas flow design (4) with at least one hole (14) in the outer shell for discharging the gas stream; wherein nozzle fingers (2) and nozzle hood (7) can be detachably connected to one another by a thread-free clamping connection, wherein the at least one hole (14) is in fluid communication with the at least one gas flow embodiment (4), if nozzle fingers (2) and nozzle hood (7) connected to each other. Air nozzle (1) according to claim 1, wherein the clamping connection is formed by rotating two elements (8, 9) on the nozzle finger (2) and nozzle hood (7) against each other. Air nozzle (1) according to claim 2, wherein the nozzle fingers (2) and nozzle hood (7) are designed such that the nozzle hood (7) engages the nozzle finger (2) in the connected state from a base plate (12) in a longitudinal direction (10). surrounds outside. Air nozzle (1) according to claim 3, wherein the nozzle finger (2) has a first connecting means (8) for producing the unthreaded clamping connection, which extends from the base plate (12) in the longitudinal direction (10) and the nozzle hood (7) a corresponding Second connecting means (9) which is suitable and intended for receiving the first connecting means (8). Air nozzle (1) according to one of the preceding claims, formed from a cast steel, preferably from an austenitic cast steel. Air nozzle (1) according to one of the preceding claims, wherein at least one of the following elements: a) at least one gas flow version (4); and b) at least one hole (14) for discharging the gas flow has a flow-through cross-section, which changes over the length of the gas flow design. Air nozzle (1) according to one of the preceding claims, wherein at least one of the following elements: a) at least one gas flow version (4) and b) at least one hole (14) tapers for discharging the gas flow from the inside to the outside. Air nozzle (1) according to one of the preceding claims, wherein at least one of the following elements: a) at least one gas flow version (4) and b) at least one hole (14) for discharging the gas flow on the inside has a widening (25), wherein the widening (25) can be described at least partially by a circular arc. Air nozzle (1) according to one of the preceding claims, further comprising an annular disc (17) for connection to a flow pipe (19) and the gas flow supply (3) of the nozzle finger (2), wherein the inner diameter (20) of the annular disc (17) substantially the outer diameter (20) of the flow pipe (19) corresponds and the outer diameter (21) of the annular disc (117) is greater than an outer diameter of the gas stream supply (3). Method for mounting an air nozzle (1) according to one of the preceding claims, in which a. an annular disc (17) is materially connected to a flow pipe (19); b. a nozzle finger (2) is materially connected to the annular disc (17); and c. a nozzle hood (7) is non-positively connected via a clamping connection with the nozzle finger.

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