EP4086511A1 - Static mixing element and static flow mixing device - Google Patents

Abstract

The invention relates to a static mixer element (10) for use in a combustion chamber (200) of an industrial boiler that can be heated with a burner device (210), the static mixer element (10) comprising a base body with a material thickness (18), which is formed from a heat-resistant material and which has a through-channel (20). The through-channel (20) runs in the direction (26) of its longitudinal axis from a front inflow side (11) through the base body to a rear outflow side (12), with several flow guide elements (30) being arranged on the inflow side (11), each of which in protrude from the inflow side (11) in the form of flat guide vanes (31), and which (30) each run from an edge section (24) of the through-channel (20) to the outer edge (13) of the inflow side (11), with between the flow guide elements ( 30) each recessed swirl surface (28) is arranged, which (28) towards the outer edge (13) of the inflow side (11) is inclined (a) in a sloping manner. A static flow mixing device (100) is also specified.

Description

The invention relates to a static mixer element for use in a combustion chamber of an industrial boiler that can be heated by a burner device, the static mixer element comprising a base body with a material thickness that is formed from a heat-resistant material and has a through-channel.

Furthermore, the invention also specifies a static flow mixing device for use in a combustion chamber of an industrial heating boiler, which comprises at least one static mixer element and at least one base plate for receiving a base section of the static mixer element.

Depending on the application, heating boilers or steam boilers with a combustion chamber known as a flame tube are known from the prior art, which are also known as flame tube/smoke tube boilers or shell boilers. Such a boiler type is used as an industrial boiler wherever the supply of heating water and/or process steam for industrial applications is concerned. Depending on the design and size, such boilers or steam boilers can provide thermal output of up to around 40 MW (megawatts).

Depending on the design, one usually speaks of a heating boiler for the supply of heating water at temperatures of up to around 80°C and of a steam boiler for the provision of process steam, for example at temperatures of 180°C and steam pressures of 10 bar, for example. For the sake of simplicity, the term “industrial heating boiler” below includes both the heating boilers mentioned above and corresponding steam boilers for the supply of process steam.

Such industrial heating boilers usually comprise a horizontally arranged, tubular or cylindrical combustion chamber, on the first end face or top surface of which a burner device protrudes into the flame tube. Firing is usually done with natural gas or fuel oil. On the front side or top surface of the flame tube opposite the burner device there is a so-called turning chamber, in which the fuel gas or flue gas from the flame tube is deflected in the longitudinal direction of the industrial boiler and enters a so-called second flue gas flue, which is usually designed as a tube bundle heat exchanger. Depending on the design of the industrial heating boiler, the flue gas can also be deflected several times in the longitudinal direction of the industrial heating boiler. For example, a so-called 3-pass flame tube boiler comprises a second and a further, third flue gas pass downstream in the flow direction of the flue gas, which is also usually designed as a tube bundle heat exchanger.

It is also known from the prior art to position heat storage elements made of heat-resistant material, for example ceramic or stainless steel, in the combustion chamber of an industrial boiler. Essentially disc-shaped heat storage elements with different geometric contour shapes, for example in the shape of a hexagon or in the shape of a circular ring with internal through-holes, have already become known for this purpose. The outer surface of these heat storage elements is essentially smooth and unstructured. The disc thickness or material thickness of such disc-shaped heat storage elements is mostly constant. Such heat storage elements are intended to delay the cooling of the combustion chamber by dissipating heat, but have the disadvantage that such heat storage elements only act as displacement bodies within the combustion chamber and impede the flow of the flue gas within the combustion chamber or can lead to a high pressure loss in the combustion chamber, as well as a reduction in the combustion chamber volume relevant for combustion. This is problematic insofar as the discharge of the flue gas in the downstream chimney can be impaired due to an excessive pressure loss due to installations in the combustion chamber and subsequently the operation of the boiler is disrupted by such installations. In addition, with a large number of heat storage elements that are positioned in a combustion chamber, the complete combustion process can be negatively influenced due to the reduced free combustion chamber volume.

The hot fuel gas stream from the burner device is turbulently swirled when it hits such a heat storage element standing transversely in the direction of flow inside the combustion chamber, but the flow around and swirling of the gas stream is undirected and random.

Another disadvantage is that when using heat storage elements made of a refractory fireclay material, such as an oven insulation of a boiler, such a heat storage element absorbs the exhaust heat of the flue gas flow only very slowly. An estimate of the transient heat conduction in a heat storage element can be determined using the combination of Biot number (Bi), Fourier number (Fo) and the dimensionless mean temperature (Θ) in the heat storage element. The Biot number reflects the ratio of the thermal resistance within a solid body to the convective heat transfer resistance in the surrounding fluid. With large Biot numbers (Bi >>1), the convective heat transfer becomes so large that the surface temperature of the body corresponds to the temperature of the surrounding fluid and, due to the low heat conduction in the solid body, shows a clear gradient to the temperature inside the body.

In the case of heat storage elements with the refractory materials typically used and high layer thicknesses, an increased core temperature can therefore only be reached after several hours (e.g. after 8 hours with core temperatures of over 700 °C). This also has a negative effect on an assumed heat storage.

Since the heat storage elements that have been known to date have a comparatively small heat capacity in relation to the available heating water volume of an industrial boiler (approx. 5% of the heating water volume, which could theoretically only be achieved with maximum uniform heating of the heat storage elements), their heat storage effect is comparatively low. Including the transient heat conduction in a heat storage element (taking into account the Biot number), heat capacities of only 2 to 3% are usually achieved compared to the storage effect of the heating water volume of a typical industrial boiler.

Another disadvantage is that if several such heat storage elements are arranged one behind the other in the inflow direction of the flue gas within the combustion chamber, the downstream heat storage elements are positioned in the flow shadow of the first heat storage element that is subjected to the frontal flow, which is why the downstream heat storage elements, in particular made of refractory material, are heated even more slowly than the frontal one flown, in the direction of flow foremost or first heat storage element.

According to the specifications of the manufacturer of industrial heating boilers and the current literature on the design of industrial heating boilers, the combustion chamber or the flame tube must in any case be operated without internal installations in the form of such heat storage elements.

• Intensivierte und relativ vergleichmäßigte Wärmestrom-Verteilung in der Brennkammer an der für den Wärmetransport in das Heizmedium wichtigen Oberfläche der Brennkammerwand;
• Intensivierte und relativ vergleichmäßigte Verwirbelung von Brenngas in der Brennkammer;
• bei Einhaltung der durch die Kesselnorm EN 12953 vorgeschriebenen maximalen Wärmestromdichte an der Brennkammerwand von 0,24 W/mm²;
• Erhöhung des Anteils der Wärmestrahlung für den Wärmetransport in der Brennkammer;
• Verringerung von Turbulenzen in der der Brennkammer nachfolgenden Wendekammer;
• Dadurch de facto gleichbleibender Druckverlust in Brennkammer und Wendekammer bis zum Eintritt in den zweiten Rauchgaszug;
• Verringerung von thermischen Schäden, die oft an der Wendekammerrückwand sowie am sonst thermisch belasteten Eintritt in den zweiten Rauchgaszug auftreten können;
• Verringerung von Kesselvibrationen, die oft durch Turbulenzen in der Wendekammer hervorgerufen werden;
• Verringerung von Schäden durch die im Betrieb anliegenden Zugkräfte an den Schweißnähten der Brennkammer, die aufgrund der hydrodynamischen Auftriebskräfte der Brennkammer auftreten;
• Brennstoffeinsparung durch einen erhöhten Wärmetransport in das Heizmedium bereits in der Brennkammer.

The object of the present invention is to overcome the disadvantages of such heat storage elements which have become known from the prior art and to provide a static mixer element which is suitable for use in a combustion chamber of a generic industrial heating boiler and which can be used during operation of an industrial heating boiler which is equipped with a equipped with the static mixer element according to the invention within its combustion chamber, the following advantages can be achieved in comparison to a combustion chamber without internals:

• Intensified and relatively even heat flow distribution in the combustion chamber on the surface of the combustion chamber wall that is important for heat transport into the heating medium;
• Intensified and relatively equalized turbulence of fuel gas in the combustion chamber;
• in compliance with the maximum heat flow density at the combustion chamber wall of 0.24 W/mm ² prescribed by boiler standard EN 12953;
• Increasing the proportion of thermal radiation for heat transport in the combustion chamber;
• Reduction of turbulence in the turning chamber following the combustion chamber;
• As a result, de facto constant pressure loss in the combustion chamber and reversing chamber until entry into the second flue gas flue;
• Reduction of thermal damage that can often occur on the rear wall of the reversing chamber and on the otherwise thermally stressed entry into the second flue gas pass;
• Reduction of bowl vibrations often caused by turbulence in the turning chamber;
• Reduction of damage caused by operational tensile forces on the combustor welds that occur due to the hydrodynamic buoyancy forces of the combustor;
• Fuel savings through increased heat transport into the heating medium already in the combustion chamber.

These objects are achieved in a static mixer element according to the preamble of claim 1 with the features of the characterizing part of claim 1. The dependent claims relate to further particularly advantageous developments of the invention.

According to the invention, in a static mixer element for use in a combustion chamber of an industrial heating boiler that can be heated with a burner device, the static mixer element comprises a base body with a material thickness which is formed from a heat-resistant material and which has a through-channel, the through-channel running in its longitudinal axis direction from a front side of the base body , the so-called inflow side, through the base body to a rear side of the base body opposite the inflow side, the so-called outflow side, the through-channel with its inlet opening being positioned essentially centrally on the inflow side of the static mixer element and several spaced-apart flow guide elements being arranged on the inflow side , which are each in the form of flat vanes, which protrude from the inflow side, are formed, and which each starting from an edge portion of the unit ritt opening of the through-channel run in the distal direction up to the outer edge of the inflow side, with a swirl surface being arranged between two flow guide elements, which is recessed in comparison to the flow guide elements and inclined towards the outer edge of the inflow side, the Flow guide elements are increased compared to an adjacent swirl surface by a vane height.

Due to its structured inflow side with a plurality of flow elements and intermediate swirl surfaces, a static mixer element according to the invention offers the additional advantage that the inflow side has a high specific surface area for a gaseous medium or a fuel gas to flow around. The term "specific surface area" means the sum of all interfaces between the structured base body, in particular on its inflow side, and a gaseous phase, i.e. the fuel gas flowing around a static mixer element, in relation to the volume of the static mixer element (m ² surface/m ³ volume). In the following, the term "structured" inflow side is used synonymously with a high specific surface area.

The term "flow guide element" is generally understood below to mean elevations in the form of flat vanes that protrude from the inflow side and impart a directed twisting movement to an inflowing gaseous medium or here to the fuel gas within a combustion chamber of an industrial boiler. During operation, the static mixer element is expediently positioned within a gas flow in such a way that the inflow direction of the combustion gas essentially corresponds to the direction of the longitudinal axis of the through-channel. The structured inflow side of the static mixer element is aligned essentially transversely to the inflow direction of the fuel gas.

Such flow guide elements can be designed, for example, as straight or curved ribs or webs, or as straight or curved blade sections. According to the invention, the flow guide elements each run in the distal direction or in the radial direction, starting from the through-channel towards the outer edge of the inflow side.

The swirl surfaces arranged between the flow guide elements are set back somewhat in the inflow direction of the combustion gas compared to the elevations of the flow guide elements and inclined by an angle of inclination α relative to a frontal plane of the inflow side, falling obliquely to the edge of the inflow side. This means that hot combustion gas flowing in the direction of the longitudinal axis of the passage channel is deflected outwards by the static mixer element in the distal or radial direction when it hits one of the sloping swirl surfaces and hits the combustion chamber wall of the industrial heating boiler distributed as evenly as possible over a wide area. It can be advantageous if the swirl surfaces are inclined at an angle of inclination α of 20° to 70°, preferably 30° to 60°, particularly preferably 45°, towards the outer edge of the inflow side.

Due to the high specific surface area described and the rapid superficial heating of a static mixer element--see the previous explanations relating to the Biot number--additionally increased radiation transport from the static mixer element to the combustion chamber wall is advantageously achieved during operation.

It can be particularly expedient if, in a static mixer element according to the invention, the through-channel has a through-channel length which essentially corresponds to the material thickness of the base body, and the several flow guide elements each have the material thickness of the base body at least in sections, with the recessed swirl surfaces in sections of the base body having a reduced material thickness are arranged.

Advantageously, the through-channel with a through-channel length that essentially corresponds to the material thickness of the base body is implicitly essentially perpendicular to the inflow side of the base body. When hot fuel gas flows against the static mixer element in the direction of the longitudinal axis of the passage channel, the inflow side of the base body is thus essentially transverse to the inflowing fuel gas and is uniformly flown around by it. A swirl flow can thus be imparted particularly effectively to the inflowing combustion gas by the flow guide elements. The swirl surfaces, which slope downwards in the outflow direction and are located in indentations in the base body or in indentations on the inflow side, are also subjected to a uniform flow of fuel gas in this design and ensure a uniformly directed deflection of the combustible gas along the edge of the inflow side in a lateral direction. As a result, the entire inner surface of the combustion chamber is advantageously evenly charged with hot combustion gas deflected by the swirl surfaces.

In a particularly advantageous embodiment of the invention, in the case of a static mixer element, the plurality of flow guide elements on the inflow side of the static mixer element can each be designed in the form of curved guide vanes with a radius of curvature. In this embodiment with curved guide vanes, the desired twisting movement, which is imposed on the fuel gas flow when it flows around at least one static mixer element, which is positioned inside a combustion chamber of an industrial boiler, can be precisely set or calculated. The smaller the radius of curvature of the curved guide vanes is selected, the more controlled turbulence can be imposed on the fuel gas flow within the combustion chamber downstream of the static mixer element as a result of a twisting movement. However, the pressure loss, which can increase as a result of the flow around the static mixer element with a rotating swirl movement, must be taken into account.

A static mixer element according to the invention can be particularly effective if the flow guide elements each have a variable guide element height in relation to the respective adjoining swirl surfaces, the guide element height increasing along a guide element length from the passage channel to the outer edge of the inflow side. With increasing guide element height, an increased swirl flow can be applied to the deflected portion of the fuel gas.

In a further development, in a static mixer element according to the invention, the guide element height on the inside of the guide elements adjacent to the through-channel can be from 20% to 50% of the material thickness of the static mixer element and/or the guide element height on the outside of the guide vanes adjacent to the edge of the inflow side can be from 50% to 100% of the material thickness of the static mixer element. By suitably selecting the height of the guide elements and/or the angle of inclination of the swirl surfaces, the degree of deflection of the inflowing medium to the combustion chamber wall can be regulated or optimized.

In a particularly compact embodiment of the invention, a static mixer element can have a base section with bearing surfaces on its underside and an edge of the inflow side with a round, preferably semicircular, edge contour on its upper side. The use of a base section increases the stability of a static mixer element. This is particularly advantageous because of the dynamic pressure that occurs during operation, which is generated by the fuel gas flowing around a static mixer element. A round, preferably semi-circular edge contour in the area of the upper side of a static mixer element offers the advantage of the most uniform possible gap spacing between the combustion chamber wall and the edge of the inflow side of the static mixer element during operation when installed transversely to the direction of flow of the combustion gas within a substantially cylindrical flame tube or a corresponding combustion chamber to offer.

As already described above, a static mixer element is expediently set up in the operating position within the combustion chamber of a boiler transversely to the direction of flow of the hot fuel gas.

In a first variant according to the invention, a static mixer element can be designed in one piece and preferably include an expansion joint with a joint width that extends from the passage channel to the edge of the inflow side through the entire material thickness of the static mixer element. If necessary, an expansion joint can be used to prevent thermal stresses from building up in a static mixer element during operation, which could possibly lead to cracks in the base body. In a further variant according to the invention, a static mixer element can be designed in two parts or in several parts, with the individual parts of the static mixer element being able to be connected to one another in a form-fitting manner using plug-in connections.

Such plug-in connections can, for example, comprise pin-shaped connecting elements which are arranged on one of the parts of the static mixer element and which are provided in corresponding recesses on another part of the two-part or multi-part static mixer element. The configuration as a two-part or multi-part static mixer element is advantageous in particular in the case of larger static mixer elements which, for example, have a diameter or a width on the inflow side of 500 mm or 600 mm. The assembly of such a static mixer element in its operating position within a combustion chamber of an industrial heating boiler is considerably facilitated by the multi-part structure, since the static mixer elements can become very heavy with increasing size.

In order to support the deflection or the turbulence of the combustion gas in the direction of the combustion chamber wall during operation, in a static mixer element according to the invention the through-channel can have an inlet opening with a free cross-sectional area and with an inner diameter on the inflow side and a diffuser section with a diffuser angle β in relation to the outflow side on the outflow side. wherein the diffuser section extends to the outlet opening of the through-channel on the outflow side and an inner diameter at the outlet opening is larger than the inner diameter at the inlet opening.

The divergent diffuser section, which widens towards the outlet opening in the direction of flow of the fuel gas, can have a diffuser angle β of 90° to 160°, preferably 120°, for example, and can be modeled on the diffuser of a Laval nozzle.

It can be particularly expedient if, in a static mixer element according to the invention, the through-channel has one or more connecting devices on the inflow side for the captive attachment of corresponding coupling elements of an adjustment ring within the through-channel. Two longitudinal slots, which are arranged on opposite wall sections and in the direction of the longitudinal axis of the through-channel and which serve as guides for a plug-in connection, can preferably be provided as parts of the connection device. Particularly preferably, two longitudinal slits running in the direction of the longitudinal axis and arranged on opposite wall sections of the through-channel together with transverse slits respectively downstream of the longitudinal slits can also be provided, with the transverse slits being positioned transversely thereto at the end of the longitudinal slits. These longitudinal slots and downstream Transverse slots can serve as guides for a lockable plug-in connection, for example in the form of a bayonet lock, and can be provided as parts of the connection device for fastening an adjustment ring within the through-channel.

The object mentioned at the outset is also achieved by a static flow mixing device which is suitable for use in a combustion chamber of a heating boiler and which comprises at least one static mixer element and at least one base plate to which the at least one static mixer element can be connected. According to the invention, the at least one standing plate has one or more recesses for receiving a base section of a static mixer element in a form-fitting manner.

Depending on the embodiment, a static flow mixing device according to the invention can also include a base plate, which can be positioned at the bottom, i.e. below the base plate, and which expediently has base feet to compensate for any unevenness and allows the static mixer elements to be positioned exactly horizontally in the operating position within a cylindrical combustion chamber. Furthermore, a static flow mixing device can optionally also comprise one or more base plates, which can be placed between the base plate and a base plate if necessary. Thus, a static flow mixer device can comprise a plurality of components which can be connected to one another in the form of a stack and which can be used to adjust the height of the at least one static mixer element in its operating position within a combustion chamber of a heating boiler. One or more components, which the set includes a static flow mixing device, can expediently also be designed in such a way that they can be positively connected to one another and, in the event of a turbulent flow of hot combustion gas within the combustion chamber, are connected in a stationary manner in their relative position in the assembly of the components.

It can be particularly advantageous if, in a static flow mixing device, which also includes at least one adjustment ring with a longitudinal axis direction, an outer diameter and a free inner diameter, the at least one adjustment ring can be fastened, preferably coaxially, on the inflow side within the through-channel of a static mixer element.

The free inner diameter of an adjustment ring defines its inner free cross-sectional area. Depending on the selection of the diameter ratio between the outside diameter and the free inside diameter, the wall thickness of the setting ring is also influenced. The free cross-sectional area of the through-channel can be changed or reduced by inserting an adjusting ring into the through-channel. Advantageously, the flow profile or the flow cross section in the through-channel of a static mixer element can be adjusted in a particularly simple and cost-effective manner. The main body of the static mixer element can, for example, in a specific Geometry and size suitable for the combustion chamber dimensions of a defined industrial boiler can be manufactured in larger quantities. By using individually shaped adjustment rings, in particular with different free inner diameters, a static flow mixing device according to the invention can then be easily adapted to the respective flow conditions.

In a static flow mixing device, the at least one adjustment ring can expediently have external coupling elements, with the at least one adjustment ring being captively fastened on the inflow side within the through-channel of a static mixer element, preferably to connecting devices within the through-channel.

In this embodiment, an adjustment ring can be attached particularly easily and securely within the through-channel. Advantageously, in an embodiment with divided static mixer elements, which can therefore be assembled from two or more individual parts, the inserted adjusting ring can also support the individual parts of the static mixer element statically and improve the overall stability of the structure of such a static flow mixing device. When assembling a static mixer element composed of several parts, a higher stability of the structure is additionally achieved by a modular adjustment ring.

In a further advantageous embodiment of the invention, in a static flow mixing device, two or more static mixer elements can be fastened one behind the other on one or more base plates, with the passage channels of the two or more static mixer elements preferably being arranged coaxially one behind the other, and with at least those downstream of a first static mixer element on the inflow side Static mixer elements, preferably all static mixer elements, are each equipped with an adjustment ring fastened in their respective through-channel.

In a development of such a flow mixing device according to the invention, which comprises two or more adjustment rings with different inner diameters, the two or more adjustment rings can be arranged such that the inner diameters of the adjustment rings decrease in the static mixer elements arranged one behind the other on the outflow side.

The inside diameters of the adjustment rings are therefore smaller on the outflow side, viewed in the inflow direction of the combustion gas. The use of different inner diameters means that the fuel gas flowing along the horizontal axis of the combustion chamber is distributed over a number of static mixer elements.

Furthermore, within the scope of the invention, a combustion chamber of an industrial heating boiler that can be heated with a combustion device can be specified with a static flow mixing device according to the invention, the flow mixing device being positioned in the combustion chamber in such a way that the inflow side of the at least one static mixer element is essentially transverse to an inflow direction of a gaseous flow medium is set up, wherein the longitudinal axis direction of the at least one through-channel and/or the longitudinal axis direction of the at least one adjustment ring is/are arranged parallel to the longitudinal axis direction of the combustion chamber, preferably coaxially with the longitudinal axis direction of the combustion chamber.

As described above, by suitably positioning such a static flow mixing device in the combustion chamber of an industrial boiler during operation, the inflow of the gaseous flow medium or the hot fuel gas flow is divided into several flow paths: A flow path of the fuel gas flow leads through the one or more through-channels arranged one behind the other several static mixer elements positioned one behind the other, where appropriate several plug-in rings, the free inner cross-sectional areas of which can preferably taper in the outflow direction.

One or more further flow paths of the hot combustion gas stream can be defined on the outside when flowing around the one or more static mixer elements, the combustion gas being deflected to the wall of the combustion chamber by hitting the inclined swirl surfaces. The guide elements or guide vanes ensure that a controlled turbulent swirl flow is imposed on the fuel gas flow.

Also within the scope of the invention is an industrial boiler having a combustion chamber in which a static flow mixing device according to the invention is positioned. The advantages mentioned above also apply equally to a combustion chamber or to an industrial heating boiler with a combustion chamber that is or are equipped with static mixer elements according to the invention or with a static flow mixing device according to the invention.

• Fig. 1 in einer isometrischen Ansicht schräg von vorne eine erste Ausführungsvariante eines Statikmischerelements gemäß der Erfindung;
• Fig. 1A in einer vergrößerten Darstellung ein Detail aus Fig. 1;
• Fig. 2 in einer Frontalansicht von vorne das in Fig. 1 dargestellte Statikmischerelement;
• Fig. 3 eine Schnittansicht von oben gemäß der in Fig. 2 dargestellten Schnittlinie A-A des in Fig. 1 dargestellten Statikmischerelements;
• Fig. 4 eine Schnittansicht von der Seite gemäß der in Fig. 2 dargestellten Schnittlinie B-B des in Fig. 1 dargestellten Statikmischerelements;
• Fig. 5A bis 5C jeweils in isometrischen Ansichten schräg von vorne unterschiedlichen Varianten von Einstellringen zur Befestigung an einem Statikmischerelement;
• Fig. 6 in einer isometrischen Ansicht schräg von der Seite eine Sockelplatte als Teil einer statischen Strömungsmischeinrichtung gemäß der Erfindung;
• Fig. 7 in einer isometrischen Ansicht schräg von der Seite eine Standplatte als Teil einer statischen Strömungsmischeinrichtung gemäß der Erfindung;
• Fig. 8 in einer isometrischen Ansicht schräg von oben eine erste Ausführung einer statischen Strömungsmischeinrichtung gemäß der Erfindung mit zwei Statikmischerelementen gemäß Fig. 1;
• Fig. 9 in einer Explosionsdarstellung schräg von der Seite die Einzelteile des in Fig. 8 gezeigten Aufbaus;
• Fig. 10 in einer isometrischen Ansicht schräg von der Seite eine zweite Ausführung einer statischen Strömungsmischeinrichtung gemäß der Erfindung mit sechs hintereinander positionierten Statikmischerelementen gemäß Fig. 1;
• Fig. 11 in einer isometrischen Ansicht schräg von vorne eine zweite Ausführungsvariante eines Statikmischerelements gemäß der Erfindung;
• Fig. 12 in einer Explosionsdarstellung schräg von der Seite die Einzelteile des in Fig. 11 gezeigten Aufbaus;
• Fig. 13 in einer Explosionsdarstellung schräg von der Seite die Einzelteile einer dritten Ausführung einer statischen Strömungsmischeinrichtung gemäß der Erfindung mit zwei Statikmischerelementen gemäß Fig. 11;
• Fig. 14 in einer isometrischen Ansicht schräg von vorne eine dritte Ausführungsvariante eines Statikmischerelements gemäß der Erfindung;
• Fig. 15 in einer Explosionsdarstellung schräg von der Seite die Einzelteile des in Fig. 14 gezeigten Aufbaus;
• Fig. 16 in einer isometrischen Ansicht schräg von oben eine vierte Ausführung einer statischen Strömungsmischeinrichtung gemäß der Erfindung mit zwei Statikmischerelementen gemäß Fig. 15;
• Fig. 17 in einer Explosionsdarstellung schräg von der Seite die Einzelteile des in Fig. 16 gezeigten Aufbaus;
• Fig. 18 in einer teilweisen Schnittansicht schräg von der Seite eine Brennkammer eines Industrieheizkessels mit einer statischen Strömungsmischeinrichtung mit sechs hintereinander angeordneten Statikmischerelementen gemäß der Erfindung, wobei die Strömungsmischeinrichtung im Innenraum der Brennkammer aufgestellt ist.

Further features of the invention result from the following description of exemplary embodiments and with reference to the drawings. In the schematic drawings show:

• 1 in an isometric view obliquely from the front, a first embodiment of a static mixer element according to the invention;
• Figure 1A a detail in an enlarged view 1 ;
• 2 in a frontal view from the front the in 1 illustrated static mixer element;
• 3 a sectional view from above according to FIG 2 illustrated cutting line AA of the in 1 illustrated static mixer element;
• 4 a sectional view from the side according to FIG 2 illustrated cutting line BB of the in 1 illustrated static mixer element;
• Figures 5A to 5C each in isometric views obliquely from the front, different variants of adjustment rings for attachment to a static mixer element;
• 6 in an isometric view obliquely from the side, a base plate as part of a static flow mixing device according to the invention;
• 7 in an isometric view obliquely from the side, a stand plate as part of a static flow mixing device according to the invention;
• 8 in an isometric view obliquely from above, a first embodiment of a static flow mixing device according to the invention with two static mixer elements 1 ;
• 9 in an exploded view diagonally from the side the individual parts of the in 8 structure shown;
• 10 in an isometric view obliquely from the side, a second embodiment of a static flow mixing device according to the invention with six static mixer elements positioned one behind the other according to FIG 1 ;
• 11 in an isometric view obliquely from the front, a second embodiment of a static mixer element according to the invention;
• 12 in an exploded view diagonally from the side the individual parts of the in 11 structure shown;
• 13 in an exploded view obliquely from the side, the individual parts of a third embodiment of a static flow mixing device according to the invention with two static mixer elements 11 ;
• 14 in an isometric view obliquely from the front, a third embodiment of a static mixer element according to the invention;
• 15 in an exploded view diagonally from the side the individual parts of the in 14 structure shown;
• 16 in an isometric view obliquely from above, a fourth embodiment of a static flow mixing device according to the invention with two static mixer elements 15 ;
• 17 in an exploded view diagonally from the side the individual parts of the in 16 structure shown;
• 18 in a partial sectional view obliquely from the side, a combustion chamber of an industrial boiler with a static flow mixing device with six static mixer elements arranged one behind the other according to the invention, the flow mixing device being set up in the interior of the combustion chamber.

The other figures are schematic representations of CFD calculations, each in diagram form based on the flow velocity (Flow velocity) in [m/s], the heat flux density (Convection_Wall_Heatflux) in [W/m2] and the temperature (Temperature-Celsius ) in [°C] illustrate differences between the flow conditions in a combustor without internals compared to the same combustor with internals in the form of static flow mixing devices according to the invention. With regard to the heat flux density, increased heat transport is represented by negative values, which are illustrated as "white areas" in the figures below. The smaller the local value of the heat flux density, the greater the outward heat flow.

• Fig. 19 in einer Seitenansicht den Verlauf der Strömungsgeschwindigkeit in einer Brennkammer eines 2 MW-Industrieheizkessels ohne Einbauten;
• Fig. 20 in einer isometrischen Schnittansicht schräg von oben den Verlauf der Wärmestromdichte an der Brennkammerwand des 2 MW-Industrieheizkessels ohne Einbauten;
• Fig. 21 in einer Seitenansicht den Verlauf der Temperatur in der Brennkammer des 2 MW-Industrieheizkessels ohne Einbauten;
• Fig. 22 in einer Seitenansicht den Verlauf der Strömungsgeschwindigkeit in der Brennkammer des 2 MW-Industrieheizkessels mit einer fünften Ausführung einer erfindungsgemäßen statischen Strömungsmischeinrichtung, die sechs hintereinander angeordnete Statikmischerelemente mit einer Breite jeweils von 300 mm umfasst;
• Fig. 23 in einer isometrischen Schnittansicht schräg von oben den Verlauf der Wärmestromdichte an der Brennkammerwand des 2 MW-Industrieheizkessels mit der fünften Ausführung der Strömungsmischeinrichtung (Breite von 300 mm);
• Fig. 24 in einer Seitenansicht den Verlauf der Temperatur in der Brennkammer des 2 MW-Industrieheizkessels mit der fünften Ausführung der Strömungsmischeinrichtung (Breite von 300 mm);
• Fig. 25 in einer Seitenansicht den Verlauf der Strömungsgeschwindigkeit in einer Brennkammer eines 10 MW-Industrieheizkessels ohne Einbauten;
• Fig. 26 in einer isometrischen Schnittansicht schräg von oben den Verlauf der Wärmestromdichte an der Brennkammerwand des 10 MW-Industrieheizkessels ohne Einbauten;
• Fig. 27 in einer Seitenansicht den Verlauf der Temperatur in der Brennkammer des 10 MW-Industrieheizkessels ohne Einbauten;
• Fig. 28 in einer Seitenansicht den Verlauf der Strömungsgeschwindigkeit in der Brennkammer des 10 MW-Industrieheizkessels mit einer sechsten Ausführung einer erfindungsgemäßen statischen Strömungsmischeinrichtung, die sechs hintereinander angeordnete Statikmischerelemente mit einer Breite jeweils von 600 mm umfasst;
• Fig. 29 in einer isometrischen Schnittansicht schräg von oben den Verlauf der Wärmestromdichte an der Brennkammerwand des 10 MW-Industrieheizkessels mit der sechsten Ausführung der Strömungsmischeinrichtung (Breite von 600 mm);
• Fig. 30 in einer Seitenansicht den Verlauf der Temperatur in der Brennkammer des 10 MW-Industrieheizkessels mit der sechsten Ausführung der Strömungsmischeinrichtung (Breite von 600 mm);
• Fig. 31 in einer Diagrammdarstellung anhand von Geschwindigkeitsvektoren die Strömungsgeschwindigkeit (Flow velocity) in [m/s] bei der Anströmung einer in Anströmrichtung eines gasförmigen Mediums gelegenen vorderen Anströmseite der statischen Strömungsmischeinrichtung gemäß der fünften Ausführung der Erfindung (Breite von 300 mm); und
• Fig. 32 in einer Diagrammdarstellung anhand von Geschwindigkeitsvektoren die Strömungsgeschwindigkeit (Flow velocity) in [m/s] bei der Anströmung einer in Anströmrichtung eines gasförmigen Mediums gelegenen vorderen Anströmseite der statischen Strömungsmischeinrichtung gemäß der sechsten Ausführung der Erfindung (Breite von 600 mm).

Show it:

• 19 in a side view the course of the flow velocity in a combustion chamber of a 2 MW industrial boiler without internals;
• 20 in an isometric sectional view obliquely from above, the course of the heat flow density on the combustion chamber wall of the 2 MW industrial boiler without internals;
• 21 in a side view, the course of the temperature in the combustion chamber of the 2 MW industrial boiler without internals;
• 22 in a side view the course of the flow velocity in the combustion chamber of the 2 MW industrial heating boiler with a fifth embodiment of a static flow mixing device according to the invention, which comprises six static mixer elements arranged one behind the other, each with a width of 300 mm;
• 23 in an isometric sectional view obliquely from above, the course of the heat flow density on the combustion chamber wall of the 2 MW industrial boiler with the fifth embodiment of the flow mixing device (width of 300 mm);
• 24 in a side view, the course of the temperature in the combustion chamber of the 2 MW industrial boiler with the fifth embodiment of the flow mixing device (width of 300 mm);
• 25 in a side view the course of the flow velocity in a combustion chamber of a 10 MW industrial boiler without internals;
• 26 in an isometric sectional view obliquely from above, the course of the heat flow density on the combustion chamber wall of the 10 MW industrial boiler without internals;
• 27 in a side view, the course of the temperature in the combustion chamber of the 10 MW industrial boiler without internals;
• 28 in a side view the course of the flow velocity in the combustion chamber of the 10 MW industrial heating boiler with a sixth embodiment of a static flow mixing device according to the invention, which comprises six static mixer elements arranged one behind the other, each with a width of 600 mm;
• 29 in an isometric sectional view obliquely from above, the course of the heat flow density on the combustion chamber wall of the 10 MW industrial boiler with the sixth embodiment of the flow mixing device (width of 600 mm);
• 30 in a side view, the course of the temperature in the combustion chamber of the 10 MW industrial boiler with the sixth embodiment of the flow mixing device (width of 600 mm);
• 31 in a diagram representation based on velocity vectors, the flow velocity (flow velocity) in [m/s] in the case of the inflow of a front inflow side of the static flow mixing device located in the inflow direction of a gaseous medium according to the fifth embodiment of the invention (width of 300 mm); and
• 32 in a diagram representation based on velocity vectors, the flow velocity (flow velocity) in [m/s] in the case of the inflow of a front inflow side of the static flow mixing device in the inflow direction of a gaseous medium according to the sixth embodiment of the invention (width of 600 mm).

In general, the assignment of the terms with regard to a location or an orientation, such as "horizontal", "vertical", "in the horizontal direction", "in the vertical direction", "above", "below", "laterally", "front","underneath","above" etc. are chosen for convenience only and such terms may refer to what is shown in the drawings, but not necessarily to an actual position of use or installation of the static mixer element or static flow mixing device within a combustion chamber of an industrial boiler.

The figures are now described in detail below. For the sake of simplicity, components with the same function are provided with the same reference symbols in different embodiment variants.

The figures Figures 1 to 4 12 each show different views of a first embodiment variant of a static mixer element 10 according to the invention.

The static mixer element 10 is made here in one piece from a heat-resistant ceramic material and has a base body with a front side 11, which is referred to below as the inflow side 11, and a rear side 12, which is referred to as the outflow side 12 below. The rear outflow side 12 is opposite the front inflow side 11 .

The inflow side 11 here has an upper or lateral edge 13 with an essentially semicircular contour. On its underside, the static mixer element 10 has a base section 14 with a width 15 and with bearing surfaces 16. The bearing surfaces 16 of the base section 14 are each inclined here and serve as standing surfaces for the static mixer element 10 in conjunction with a standing plate, such as those shown in 7 is shown.

The base body of the static mixer element 10 has a width 17, a maximum material thickness 18 or initial depth and a height 19. The base body of the static mixer element 10 also has a through-channel 20 which, with its inlet opening 21, is positioned essentially centrally on the inflow side 11 of the static mixer element 10 is.

The through-channel 20 has its outlet opening 22 on the outflow side 12 . A free cross-sectional area 23 of the through-channel 20 is essentially circular here with an inner diameter D _E of the through-channel 20 in the region of its inlet opening 21 . The inlet opening 21 is bordered here by a peripheral edge section 24 or edge web on the inflow side 11, this edge section 24 or edge web having an outer diameter D _R .

Seen from its inlet opening 21, the through-channel 20 is designed as a diffuser section 25 from about halfway up to the outlet opening 22, with an inner diameter D _A of the diffuser section 25 at the outlet opening 22 being larger than the inner diameter D _E of the through-channel 20 in the region of its inlet opening 21 A diffuser angle β is selected here, for example, at 120°.

The direction of the longitudinal axis 26 of the through-channel 20 is symbolized by a dot-dash line 26 . The through-channel 20 thus runs in the direction of the longitudinal axis 26 and with a channel length 27 from the front or inflow side 11 of the base body through the base body to the rear or outflow side 12 of the base body.

In a three-dimensional coordinate system, the longitudinal axis direction 26 of the through channel 20 corresponds to the X-axis direction. The Y axis direction indicates the lateral width direction 17 of the static mixer element 10 , the Z axis direction indicates the height direction 19 of the static mixer element 10 .

The static mixer element 10 is structured on the inflow side 11 and has a plurality of swirl surfaces 28 which are each inclined towards the outer edge 13 of the inflow side 11 at an angle of inclination α. Furthermore, a plurality of flow guide elements 30 spaced apart from one another are arranged on the inflow side 11 and are each in the form of flat guide vanes 31 which protrude from the inflow side 11 . The flow guide elements 30 each run from the edge section 24 of the inlet opening 21 of the through-channel 20 approximately in the distal or radial direction to the outer edge 13 of the inflow side 11. The guide vanes 31 have a guide vane width 32 or width 32 of the flow guide element 30 and a guide vane length 33 or length 33 of the flow guide element 30. The guide vanes 31 are designed here in the form of curved guide vanes 31 with a radius of curvature 34 .

In even more detail, the radius of curvature 34 of a guide vane 31 can be specified as a first, somewhat larger radius of curvature R, which is measured at a first flank 35 of the guide vane 31, which is concavely curved. Along this first flank 35, the guide vane 31 protrudes beyond the lower-lying swirl surface 28 adjoining the first flank 35 by an inner guide vane height 36 or guide element height 36, which on the inside of the guide vane 31 adjoins the edge section 24 around the inlet opening 21 of the through-channel 20 is measured. An outer guide vane height 37 or guide element height 37 is measured on the first flank 35 on the edge 13 of the inflow side 11 .

A second flank 38 of the guide vane 31 or of the flow guide element 30, which is convexly curved and is opposite the first flank 35, has a radius of curvature r which is somewhat smaller than the radius of curvature R. The ratio between the larger radius of curvature R on the first flank 35 and the smaller radius of curvature r on the second flank 38 of the guide vane 31 or the flow guide element 30 depends essentially on the selection of the guide vane width 32 and on the size of the radii of curvature R, r. For the sake of simplicity, reference is made below to a radius of curvature 34, which is, so to speak, a mean value of the two radii of curvature R and r.

Along the second edge 38, the vane 31 projects beyond the second flank 38 adjacent, deeper swirl surface 28 by an inner vane height 39 or vane height 39, which is on the inside of the vane 31 adjacent to the Edge section 24 around the inlet opening 21 of the passage channel 20 is measured. An outer guide vane height 40 or guide element height 40 is measured on the second flank 38 on the edge 13 of the inflow side 11 .

The flow guide elements 30 are therefore increased by a vane height 36, 37, 39, 40 in comparison to the respective adjoining swirl surfaces 28. The material thickness 18 of the base body of the static mixer element 10 is reduced in the region of the recessed swirl surfaces 28 and has only a reduced material thickness 18.1 or 18.2 in the region of the swirl surfaces 28. Due to the recesses in the base body in the area of the inclined swirl surfaces 28, the total weight of the static mixer element 10 according to the invention is reduced in comparison to a base body with a constant material thickness 18 and with a smooth, unstructured front side. The reduced overall weight and the associated saving in material of a static mixer element 10 according to the invention offers numerous advantages: a static mixer element 10 according to the invention can be produced inexpensively due to the material saved compared to an unstructured base body and is easier to handle.

In order to withstand temperature stresses in the base body during use in a combustion chamber of an industrial heating boiler with as little damage as possible, the static mixer element 10 shown here has an expansion joint 45 with a joint width 46, which extends along the top side of the static mixer element 10 along its entire material thickness 18 from the passage 20 to the edge 13 extends.

To make it easier to understand how this static mixer element 10 works in operation within a combustion chamber of an industrial boiler, as is the case, for example, in 18 shown schematically is in 1 and partly also in the following figures also an inflow direction 1, symbolized as arrow 1, sketched, which is intended to illustrate the inflow direction of a gaseous medium, the flue gas, within the combustion chamber of an industrial boiler, not shown here. The inflow direction 1 essentially corresponds to the X-axis direction or the longitudinal axis direction 26 of the through-duct 20. Or, to put it another way, such a static mixer element 10 according to the invention is arranged during operation within a combustion chamber of an industrial heating boiler in such a way that the longitudinal axis direction 26 of the through-duct 20 is essentially in the inflow direction 1 of the flue gas is oriented. The inflow side 11 of the base body is thus essentially transverse to the inflow direction 1 of the flue gas.

A first flow path 2 of the gaseous medium, symbolized by a dash-dotted line 2 and by arrows 2 , leads in the direction of the longitudinal axis 26 through the through-channel 20 of the static mixer element 10 . Another second Flow path 3 of the gaseous medium, symbolized by a dashed line 3 and by arrows 3, shows schematically the course of the flow of the flue gas as it flows around the static mixer element 10 on the outside along the flow guide elements 30 offset by a twisting movement and deflected in the lateral or axial direction by the static mixer element 10 in the direction of an inner wall of the combustion chamber, not shown here, when it hits the twisting surface 28 .

In 1 as well as partially also in the following figures, an inflow plane ε is also indicated with a dot-dash contour line. The inflow plane ε conceptually forms a frontal plane on the structured inflow side 11, in which those contour sections are located which, viewed in the inflow direction 1 of the flowing medium in the X-axis direction, are flown against first. Or to put it another way, the inflow plane ε comprises those contour sections on the inflow side 11 which protrude farthest from the inflow side 11 as elevations against the inflow direction 1 . These are here the curved front surfaces of the guide vanes 31 each with a guide vane width 32 and a guide vane length 33, as well as the peripheral edge section 24 or edge web, which borders the inlet opening 21 of the through channel 20 on the inflow side 11. In the following figures 31 and 32 the velocity profiles are shown in vector representation at the inflow plane ε or frontal plane of the structured inflow side 11 of static mixer elements 10 according to the invention. The swirl surfaces 28 between the guide vanes 31 are located somewhat downstream of the inflow plane ε or the frontal plane in the inflow direction 1 or in the X-axis direction, which is why they are also shown in the illustrations 31 and 32 are not shown.

The other illustrations Figures 5A to 5C each relate to different variants of adjustment rings 60 for attachment to a static mixer element 10. Each adjustment ring 60 is essentially cylindrical in shape and has an outer diameter d _A , an inner diameter d _I and a wall thickness of the cylinder jacket, which in each case results from the difference between the outer diameter d _A to inner diameter d _I results. Each adjusting ring 60 has an edge 61 on one of the edges of the cylinder jacket, which has an enlarged edge diameter compared to the outer diameter d _A and which projects beyond the cylinder jacket of the adjusting ring 60 to the outside. A longitudinal axis direction 62 of the setting ring 60 is symbolized by a dash-dotted line 62 . A length 63 or depth of the setting ring 60 is measured on the outside away from the edge 61 and indicates the length or height of the cylinder jacket of the setting ring 60 .

Figure 5A 1 shows a first adjusting ring 60.1 with an outer diameter d _A and with a first inner diameter d _I .1.

Figure 5B 1 shows a second adjustment ring 60.2 with an outer diameter d _A that is the same as the outer diameter d _A of the first adjustment ring 60.1, and with a second inner diameter d _I .2 that is smaller than the first inner diameter d _I .1. Consequently, the second adjustment ring 60.2 has a reduced free cross-sectional area in comparison to the first adjustment ring 60.1. The wall thickness of the cylinder jacket is greater in the case of the second adjustment ring 60.2 than in the case of the first adjustment ring 60.1.

Figure 5C shows a third adjustment ring 60.2 with an outer diameter d _A that is the same as the outer diameter d _A of the first and second adjustment rings 60.1, 60.2, and with a third inner diameter d _I .3 that is smaller than the first inner diameter d _I .1 and is smaller than the second inner diameter d _I .2. Consequently, the third adjustment ring 60.3 has a further reduced free cross-sectional area in comparison to the second adjustment ring 60.2. The wall thickness of the cylinder jacket is even greater for the third setting ring 60.3 than for the second setting ring 60.3.

With the ones in the pictures Figures 5A to 5C Illustrated adjustment rings 60.1, 60.2, 60.3, each with a different inner diameter d _I .1, d _I .2, d _I .3 with otherwise the same dimensions, a set of adjustment rings 60 is provided which, if necessary, is inserted and fastened in the inlet opening 21 of the through-channel 20 can become. With the help of the insertable adjusting rings 60.1, 60.2, 60.3, the free cross-sectional area 23 of the through-channel 20 can thus be further reduced very easily.

One or more connecting devices 50 are provided within the through-channel 20 on the inflow side, i.e. starting from the inlet opening 21, which preferably comprise two longitudinal slots 51, which are arranged on opposite wall sections and in the direction of the longitudinal axis 26 of the through-channel 20 and which serve as guides for a plug-in connection. The illustrations Figures 1 to 4 show a particularly preferred variant in the form of guides of a lockable plug-in connection or a bayonet catch with two longitudinal slots 51 running in the direction of the longitudinal axis 26 and arranged on opposite wall sections of the through-channel 20, together with transverse slots 52, which are each arranged downstream of the longitudinal slots 51. The transverse slots 52 are each positioned at the end of the longitudinal slots 51 transversely thereto.

For captive attachment of an adjustment ring 60 within the through-channel 20, each adjustment ring 60 has external coupling elements 53 which protrude laterally beyond the outer cylindrical surface of the adjustment ring 60. The coupling elements 53 are designed in the form of protruding pins or buttons and correspond with the longitudinal slots 51 and the transverse slots 52. Each adjusting ring 60 is designed in such a way that it can be inserted into the inlet opening 21 of a through-channel 20, with the coupling elements 53 on the adjusting ring 60 engaging in the corresponding longitudinal slots 51 on the walls of the through-channel 20. For this purpose, the adjusting ring 60 is inserted coaxially with its longitudinal axis direction 62 in the direction of the longitudinal axis 26 of the through-channel 20 in the X-axis direction until the peripheral edge 61 of the adjusting ring 60 rests against the edge section 24 of the through-channel 20 . If the connection device 50 is designed as a lockable plug-in connection, the inserted adjustment ring 60 can be captively secured by rotating it about its longitudinal axis direction 62 . The coupling elements 53 engage in the transverse slots 52 of this bayonet lock. If necessary, the adjusting ring 60 can be separated from the static mixer element 10 again by turning it in the opposite direction of rotation and by pulling it out in the direction of the longitudinal axis 26 of the through-channel 20 .

6 Figure 12 shows a base plate 70 as part of a static flow mixing device according to the invention. The base plate 70 is essentially cuboid here and has two base feet 71 on its underside, which extend in the longitudinal direction of the base plate 70 in the form of strips. The base feet 71 offer the advantage of being able to compensate for unevenness in the ground at the installation site of a static flow mixing device, in particular inside a combustion chamber of an industrial heating boiler. On the upper side of the base plate 70 lateral guide profiles 72 are arranged in the longitudinal direction, which can serve to guide other components.

7 Figure 8 shows a pedestal 80 as part of a static flow mixing device according to the invention. The standing plate 80 shown here has two recesses 81 on its upper side, into each of which a base section 14 of a static mixer element 10 can be inserted in a form-fitting manner. The two recesses 81 each have sloping bearing surfaces here, which correspond to the sloping bearing surfaces 16 of the base section 14 of a static mixer element 10 .

Lateral guide grooves 82 on the underside of the base plate 80 serve to accommodate the guide profiles 72 of the base plate 70, as shown in 6 is shown.

8 12 illustrates a first embodiment of a static flow mixer device 100 according to the invention with two static mixer elements 10 according to FIG 1 , with a base plate 70 according to 6 and with a stand plate 80 according to 7 . In order to adjust the overall height of the static flow mixing device 100 , a plurality of base plates 75 are additionally interposed here between the base plate 70 and the standing plate 80 .

9 shows the individual parts of the in an exploded view 8 structure shown. Here the three inserted base plates 75.1, 75.2, 75.3 can be clearly seen.

The two static mixer elements 10 are arranged one behind the other as viewed in the X-axis direction or in the inflow direction 1 of the inflowing medium or flue gas, in such a way that the longitudinal axis directions 26 of the passage channels 20 are positioned coaxially. In the front static mixer element 10, which is in 8 is shown in the foreground of the image, there is a first adjustment ring 60.1 with a first inner diameter d _I .1 in the through-channel 20. In the second, rear static mixer element 10 there is a second adjusting ring 60.2 in the through-channel 20 with a second inner diameter d _I .2, which is smaller than the first inner diameter d _I .1. When the flow around the static flow mixing device 100 is reduced on the flow path 2 of the inflowing medium or flue gas through the through-channels 20, the free cross-sectional area within the two adjusting rings 60.1 and 60.2 arranged one after the other.

The central opening of a static mixer element prevents excessive back pressure and excessive pressure loss in the combustion chamber. Due to the tapering inner diameter, the centrally arranged combustion gas of the combustion jet can be divided into several static mixer elements and then deflected.

The flow through the first static mixer element 10 and, associated therewith, the flow against the second flow element 10, which is located in the slipstream of the first static mixer element 10, are thus improved.

10 12 shows a second embodiment of a static flow mixing device 100 according to the invention with six static mixer elements 10 positioned one behind the other according to the embodiment of FIG 1 .

The six static mixer elements 10 are fastened here in pairs on three standing plates 80 arranged one behind the other, viewed in the X-axis direction or in the direction of flow 1, with the through-channels 20 of the six static mixer elements 10 being arranged coaxially 26 one behind the other. Corresponding base plates 70 and base plates 75.1 to 75.3 serve as a stand for the static mixer elements 10. The first or foremost static mixer element 10 on the inflow side has a through-channel 20 without an adjusting ring. The further downstream static mixer elements 10 in the X-axis direction, ie the second to sixth static mixer elements 10, are each equipped with an adjusting ring 60.1, 60.2, 60.3, 60.4, 60.5 fastened in their respective through-channel 20.

The several adjustment rings 60.1, 60.2, 60.3, 60.4, 60.5 are arranged in such a way that the inside diameters d _I .1, d _I .2, d _I .3, d _I .4, d _I .5 of the adjustment rings 60.1, 60.2, 60.3, 60.4, 60.5 in X-axis direction of the downstream static mixer elements 10 decrease or become smaller. Depending on the shape of the combustion chamber, several static mixer elements 10 can also be arranged.

11 shows a second embodiment of a static mixer element 10 according to the invention, wherein 12 in an exploded view the individual parts of the in 11 illustrated structure shown. Deviating from the one-piece or one-piece design of a static mixer element described above, the static mixer element 10 shown here is constructed in two parts and comprises a lower first part 10.1 and an upper second part 10.2, which can be positively connected by means of a plug connection 55. For this purpose, two connecting elements 56 in the form of connecting pins are arranged here on the lower first part 10.1, which can be brought into engagement with corresponding recesses 57 on the upper second part 10.2 of the divided static mixer element 10. An adjusting ring 60, which in turn can also be inserted into the through-channel 20 in this embodiment variant of a divided static mixer element 10, advantageously also serves as a support for the two parts 10.1 and 10.2 and stabilizes them in their connected position. Additional expansion joints are not required in this design with a divided base body.

13 shows in an exploded view the individual parts of a third embodiment of a static flow mixing device 100 according to the invention with two static mixer elements 10 according to 11 .

The illustrations 14 and 15 relate to a third embodiment of a static mixer element 10 according to the invention, which is assembled from three individual parts 10.1, 10.2 and 10.3. The individual parts 10.1 to 10.3 can in turn be positively connected to one another by means of plug connections 55. Additional expansion joints on the base body are not required in this version either.

The illustrations 16 and 17 10 show a fourth embodiment of a static flow mixer device 100 according to the invention with two static mixer elements 10 according to FIG 15 .

18 shows the view into a combustion chamber 200 of an industrial boiler. The combustion chamber 200 is essentially cylindrical with a longitudinal axis direction 201 and with an inner diameter 202. On its first end face, which is in 18 As can be seen in the image on the left, a burner device 210 with a burner flame 211 protrudes into the combustion chamber 200. The burner flame 211 is aligned essentially coaxially with the longitudinal axis 201 of the combustion chamber 200 for this purpose. The so-called Turning chamber in which the flue gas is deflected by about 180° and in a second flue gas pass, which is 18 is indicated only schematically in the background of the image as a bundle of cut-away tubes of a tube bundle heat exchanger, in the opposite direction to the flow direction 1 further to a flue gas chimney. Inside the combustion chamber 200 there is a static flow mixing device 100 with six static mixer elements 10 arranged one behind the other according to the invention. The static mixer elements 10 are positioned such that the longitudinal axes 26 of their passages 20 are each arranged coaxially with the longitudinal axis 201 of the combustion chamber 200 and thus also essentially coaxially with the burner flame 211 .

Regarding the benefits and effects shown in the figures Figures 19 to 32 are illustrated, it is noted as follows:
In general, the mechanisms relevant for the heat transport in a combustion chamber of a generic industrial boiler are on the one hand the convective or turbulent heat transport and on the other hand the thermal radiation due to the high flame temperature of the fuel gas at approx. 1800°C. In empty combustion chambers without internals in the form of static mixer elements, the turbulence or turbulent flow through the coaxial burner flame is relatively low, as is the case, for example, in 19 or in 25 you can see. In an empty combustion chamber without static mixer elements positioned therein, the flow speed of the combustion gas decreases, especially close to the combustion chamber wall, as a result of which the heat transfer coefficient at the combustion chamber wall is disadvantageously reduced. This is example in the pictures 20 . or. 26 illustrated. Therefore, during operation in a combustion chamber without internals, a relatively thick laminar boundary layer of the fuel gas flow forms on the combustion chamber wall, which is a hindrance to the heat transport to the combustion chamber wall. At the same time, the thermal radiation transport from the burner flame to the burner chamber wall has to overcome the comparatively longest path or distance here.

Since the heat from the combustion gas cannot be efficiently dissipated in the empty combustion chamber, the combustion gas in a combustion chamber without internals is deflected with high turbulence and at a relatively high temperature through the turning chamber into the second flue gas flue following the combustion chamber. In practice, this leads to increased thermal exposure, especially when the boiler load is high, which can lead to material damage to the rear wall of the reversing chamber or the entrance to the second flue gas pass. In addition, this is often accompanied by increased fuel consumption due to various heat losses. Due to the high turbulence of the fuel gas flow, harmful boiler vibrations can also occur, which are also disadvantageous in the operation of a such industrial boiler can be with a combustion chamber without internals according to the invention.

By installing static mixer elements according to the invention or a static flow mixing device according to the invention, the turbulence of the combustion gas is advantageously already intensified in the combustion chamber, as is shown in the figures 22 - compared to the corresponding 19 without installations - or in 28 - compared to the corresponding 25 without internals - is illustrated. The installations according to the invention significantly increase the convective heat transport on the combustion chamber wall (see the figures 23 or. 29 ). The design according to the invention of a static flow mixing device each with six static mixer elements arranged one behind the other, each structured with swirl surfaces and flow guide elements, and the suitable use of adjustment rings distributes the interaction or deflection of the inflowing combustion gas over several static mixer elements, as is the case in the illustrations 31 or. 32 can be removed. As a result, locally high heat flow densities, which can disadvantageously occur during operation in a combustion chamber without built-in components, can be minimized.

At the same time, the interaction of the fuel gas with the specifically high surface area of the static mixer elements according to the invention increases their surface temperature, whereby the use of static mixer elements according to the invention or a static flow mixing device according to the invention also increases the thermal radiation transport to the combustion chamber wall. The use of static mixer elements according to the invention or a static flow mixing device according to the invention within a combustion chamber of an industrial heating boiler advantageously lowers the temperature and speed of the combustion gas already in the combustion chamber, which also reduces the subsequent flue gas path in the area of the turning chamber and when it enters the second flue gas flue downstream thermally less exposed.

The heat transport by convection and radiation in the combustion chamber in industrial heating boilers cannot usually be analyzed in a differentiated and representative manner due to various limitations such as the very high combustion chamber temperature. However, the positive effects of using static mixer elements according to the invention or a static flow mixing device according to the invention can be determined indirectly through integral measurements, for example through fuel savings, a lower temperature distribution on the turning chamber rear wall and reduced material damage to the fireclay material for the combustion chamber lining.

In a largely quantitative combustion modeling and flow simulation of the combustion chamber, however, the heat transport in the combustion chamber can be analyzed in a differentiated manner. The heat flow at the combustion chamber wall increases significantly as a result of the installation of static mixer elements according to the invention or a static flow mixing device according to the invention in a combustion chamber.

In the exemplary embodiment of a combustion chamber of a 2 MW (megawatt) industrial boiler, in which a static flow mixing device according to the invention with six static mixer elements, each with a diameter of 300mm, is positioned (see the associated figures 22, 23, 24 such as 31 ) was able to increase the heat flow in the combustion chamber by 45% compared to the corresponding combustion chamber without internals (see Figures 19 to 21 ) be determined. While the portion of heat transport through thermal radiation in the empty combustion chamber (see 20 ) is only about 10%, the proportion of radiation due to thermal radiation is increased to 36% by installing static mixer elements according to the invention in the same combustion chamber (see 23 ).

It is essential, depending on the size or output of an industrial heating boiler with larger combustion chambers with a larger combustion chamber diameter, to carry out a corresponding scale-up of the static mixer elements according to the invention or a static flow mixing device according to the invention.

In the exemplary case of a combustion chamber of a 10 MW (megawatt) industrial heating boiler, a diameter of 600 mm can be increased by suitably adapting and enlarging the static mixer elements (see the accompanying figures 28, 29, 30 such as 32 ) even an increase in heat flow by 58% compared to the corresponding combustor without internals (see 25 to 27 ) be determined. While the portion of heat transport through thermal radiation in the empty combustion chamber (see 26 ) is only about 7%, the proportion of radiation due to heat radiation is increased to 33% by installing static mixer elements according to the invention in the same combustion chamber (see 29 ). This advantageous effect can be explained well by the increased heat radiation of the static mixer elements according to the invention.

Furthermore, a reduced thermal exposure of the flue gas path following the combustion chamber can be determined in the flow simulation, particularly in the section of the reversing chamber. The advantages of using static mixer elements according to the invention or a static flow mixing device according to the invention within a combustion chamber of a generic industrial heating boiler are therefore obvious.

LIST OF REFERENCE MARKS

1

Inflow direction, flow direction of the medium (arrow)

2

Flow path of the medium through the passage channel (arrow)

3

Flow path of the medium along a flow guide element (arrow)

10

static mixer element

10.1

first (second, third) part of the static mixer element (or 10.2, 10.3)

11

Front or upstream side of the static mixer element

12

Rear or downstream side of the static mixer element

13

Edge (section) of the inflow side of the static mixer element

14

base section

15

Width of the base section

16

Bearing surface of the base section

17

Width of the static mixer element

18

Material thickness or initial depth of the static mixer element

18.1

Reduced material thickness in the area of the twist surface (or 18.2)

19

Static mixer element height

20

Through channel of the static mixer element

21

Entry opening of the through channel

22

Outlet opening of the through channel

23

Free cross-sectional area of the passage channel

24

Edge section (edge web) of the through channel

25

diffuser section

26

Longitudinal axis direction of the through channel

27

Length of the through channel

28

Swirl surface (sloping from inside to outside)

30

flow guide element

31

vane

32

Guide vane width, width of the flow guide element

33

Guide vane length, length of the flow guide element

34

Radius of curvature of the vane (of the flow guide element) (or radii R, r)

35

first flank of the vane (of the flow guide element) (concavely curved)

36

inner vane height (vane height) at the first flank

37

outer vane height (vane height) at the first flank

38

second flank of the vane (of the flow guide element) (convexly curved)

39

inner vane height (vane height) at the second flank

40

outer vane height (vane height) at the second flank

45

expansion joint ./.

46

joint width

50

Connection device (lockable plug connection)

51

longitudinal slit

52

transverse slit

53

coupling element (knob)

55

connector

56

fastener

57

recess

60

adjustment ring

60.1

first (second, third) setting ring (or 60.2, 60.3)

61

edge of the adjustment ring

62

Longitudinal axis direction of the adjustment ring

63

Length or depth of the adjustment ring

70

base plate

71

base foot

72

(lateral) guide profile

75

Base plate (or 75.1, 75.2, 75.3)

80

stand plate

81

Recess for base portion of a static mixer element

82

Guide groove for accommodating the guide profile

100

Static Flow Mixer

200

Combustion chamber of an industrial boiler; flame tube

201

Longitudinal axis direction of the combustion chamber

202

combustion chamber diameter

210

burner device

211

burner flame

there

Outside diameter of the adjustment ring

dI

Inner diameter of the adjustment ring

dI.1

Inner diameter of the first (second, third) adjusting ring (or d _I .2, d _I .3)

EN

Inside diameter of the passage channel on the entry side

DR

Outer diameter of the edge web on the entry side

THERE

Inside diameter of the diffuser section on the exit side

X

X axis direction; in the longitudinal axis direction of the through channel

Y

Y axis direction; lateral width direction of the static mixer element

Z

Z axis direction; Height direction of the static mixer element

a

Angle of inclination of the swirl surface

β

diffuser angle

ε

Inflow plane, frontal plane on the inflow side or front side

Claims (17)

Static mixer element (10) for use in a combustion chamber (200) of an industrial boiler that can be heated with a burner device (210), the static mixer element (10) comprising a base body with a material thickness (18), which is formed from a heat-resistant material and which has a through-channel ( 20), characterized in that - the through-channel (20) runs in its longitudinal axis direction (26) from a front side of the base body, the so-called inflow side (11), through the base body to a rear side of the base body opposite the inflow side (11), the so-called outflow side (12). , wherein the passage channel (20) with its inlet opening (21) is positioned substantially centrally on the inflow side (11) of the static mixer element (10) and wherein - on the inflow side (11), several spaced-apart flow guide elements (30) are arranged, each in the form of flat guide vanes (31) that protrude from the inflow side (11), and which (30) each starting from an edge section (24) of the inlet opening (21) of the through-channel (20) in the distal direction to the outer edge (13) of the inflow side (11), wherein - Between two flow guide elements (30) there is arranged a swirl surface (28) which is recessed compared to the flow guide elements (30) and which (28) slopes downwards (a) towards the outer edge (13) of the inflow side (11), wherein the flow guide elements (30) are increased by a vane height (36, 37, 39, 40) compared to an adjacent swirl surface (28). Static mixer element (10) according to Claim 1, characterized in that the through-channel (20) has a through-channel length (27) which essentially corresponds to the material thickness (18) of the base body, and the plurality of flow guide elements (30) each have the material thickness (18 ) of the base body, the recessed twisting surfaces (28) being arranged in sections of the base body with reduced material thickness (18.1, 18.2). Static mixer element (10) according to Claim 1 or 2, characterized in that the plurality of flow guide elements (30) on the inflow side (11) of the static mixer element (10) are each in the form of curved guide vanes (31) with a radius of curvature (34, R, r) are trained. Static mixer element (10) according to one of Claims 1 to 3, characterized in that the flow guide elements (30) each have a variable guide element height (36, 37, 39, 40) in relation to the respective adjoining swirl surfaces (28), the guide element height ( 36, 37, 39, 40) along a guide element length (33) from the passage channel (20) to the outer edge (13) of the inflow side (11). Static mixer element (10) according to Claim 4, characterized in that the guide element height (36, 39) on the inside of the guide elements (30) adjoining the through-channel (20) is from 20% to 50% of the material thickness (18) of the static mixer element (10) and/or the guide element height (37, 40) on the outside of the guide vanes (31) adjoining the edge of the inflow side (11) is 50% to 100% of the material thickness (18) of the static mixer element (10). Static mixer element (10) according to one of Claims 1 to 5, characterized in that the static mixer element (10) has a base section (14) with bearing surfaces (16) on its underside and an edge (13) of the inflow side (11) with a having a round, preferably semi-circular edge contour. Static mixer element (10) according to one of Claims 1 to 6, characterized in that the static mixer element (10) is designed in one piece and preferably comprises an expansion joint (45) with a joint width (46) which extends from the passage channel (20) to the edge ( 13) of the inflow side (11) through the entire material thickness (18) of the static mixer element (10). Static mixer element (10) according to one of Claims 1 to 7, characterized in that the static mixer element (10) is designed in two parts or in several parts, the individual parts (10.1, 10.2, 10.3) of the static mixer element (10) having plug-in connections (55) with one another in a form-fitting manner are connectable. Static mixer element (10) according to one of Claims 1 to 8, characterized in that the through-channel (20) has an inlet opening (21) on the inflow side (11) with a free cross-sectional area (23) and with an inner diameter (D _E ) and on the outflow side (12) has a diffuser section (25) with a diffuser angle (β) in relation to the outflow side (12), wherein the diffuser section (25) to the outlet opening (22) of the through-channel (20) at the Outflow side (12) and an inner diameter (D _A ) at the outlet opening (22) is larger than the inner diameter (D _E ) at the inlet opening (21). Static mixer element (10) according to one of Claims 1 to 9, characterized in that the through-channel (20) for the captive attachment of corresponding coupling elements (53) of an adjustment ring (60) within the through-channel (20) has one or more connecting devices (50) on the inflow side, preferably two longitudinal slots (51), which are arranged on opposite wall sections and running in the longitudinal axis direction (26) of the through-channel (20) and which serve as guides for a plug-in connection, particularly preferably two wall sections of the through-channel running in the longitudinal axis direction (26) and opposite one another (20) arranged longitudinal slots (51) together with the longitudinal slots (51) respectively downstream transverse slots (52), wherein the transverse slots (52) are each positioned transversely at the end of the longitudinal slots (51) and which serve as guides for a lockable plug connection. Static flow mixing device (100) for use in a combustion chamber (200) of an industrial heating boiler, comprising at least one static mixer element (10) according to one of Claims 1 to 10 and at least one base plate (80) with which the at least one static mixer element (10) can be connected, characterized in that the at least one standing plate (80) has one or more recesses (81) for receiving a respective base section (14) of a static mixer element (10) in a form-fitting manner. Static flow mixing device (100) according to Claim 11, further comprising at least one adjustment ring (60) with a longitudinal axis direction (62), an outer diameter (d _A ) and a free inner diameter (d _I ), characterized in that the at least one adjustment ring (60) on the inflow side (11) within the through-channel (20) of a static mixer element (10), preferably coaxially (26, 62), fastened. Static flow mixing device (100) according to Claim 12, the at least one adjusting ring (60) having external coupling elements (53), characterized in that the at least one adjusting ring (60) is located on the inflow side within the through-channel (20) of a static mixer element (10), preferably on Connection devices (50) within the through-channel (20), is captively fastened. Static flow mixing device (100) according to one of Claims 11 to 13, characterized in that two or more static mixer elements (10) are fastened one behind the other on one or more base plates (80), the passage channels (20) of the two or more static mixer elements ( 10) are arranged coaxially (26) one behind the other, and wherein at least the static mixer elements (10) arranged downstream of a first static mixer element (10) on the inflow side, preferably all static mixer elements (10), each have an adjusting ring (60, 60.1, 60.2, 60.3, 60.4, 60.5) are equipped. Static flow mixing device (100) according to claim 14, comprising two or more adjusting rings (60, 60.1, 60.2, 60.3, 60.4, 60.5) with different inner diameters (d _I .1, d _I .2, d _I .3, d _I .4 , d _I .5), characterized in that the two or more adjustment rings (60, 60.1, 60.2, 60.3, 60.4, 60.5) are arranged in such a way that the inner diameters (d _I .1, d _I .2, d _I . 3, d _I .4, d _I .5) of the adjusting rings (60, 60.1, 60.2, 60.3, 60.4, 60.5) in the static mixer elements (10) arranged one behind the other on the outflow side. Combustion chamber (200) of an industrial heating boiler that can be heated with a combustion device (210), with a static flow mixing device (100) according to one of Claims 11 to 15, characterized in that the flow mixing device (100) is positioned in the combustion chamber (200) in such a way that the at least one static mixer element (10) is set up with its inflow side (11) essentially transverse to an inflow direction (1) of a gaseous flow medium, the longitudinal axis direction (26) of the at least one through-channel (20) and/or the longitudinal axis direction (62) of the at least an adjusting ring (60) is/are arranged parallel to the longitudinal axis direction (201) of the combustion chamber (200), preferably coaxially with the longitudinal axis direction (201) of the combustion chamber (200). Industrial heating boiler with a combustion chamber (200) according to claim 16.

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