WO2011128433A1

WO2011128433A1 - Externally mixing multi-component nozzle

Info

Publication number: WO2011128433A1
Application number: PCT/EP2011/055995
Authority: WO
Inventors: Dieter Wurz; Stefan Hartig
Original assignee: Dieter Wurz; Stefan Hartig
Priority date: 2010-04-16
Filing date: 2011-04-15
Publication date: 2011-10-20
Also published as: EP2558217A1; EP2558217B1; DE102010015497A1; PL2558217T3; CN102858466A; ES2637981T3; US20130037628A1; HUE035691T2

Abstract

The invention relates to an externally mixing multi-component nozzle for spraying fluids with the assistance of an atomizing gas that is hot in relation to the fluids to be sprayed, said gas particularly being steam or hot gas. The nozzle has a housing, wherein the housing has an outlet orifice for the atomizing gas, a first annular gap for fluid to be sprayed, surrounding the outlet orifice, and a second annular gap for the atomizing gas, surrounding the first annular gap, as well as a manifold. The manifold has at least one flow channel for fluid to be sprayed, from a connecting line to the first annular gap, and at least one flow channel from an atomizing gas connecting line to the outlet orifice for atomizing gas.

Description

description

Externally mixing multi-substance nozzle

The invention relates to an externally mixing Mehrstoffdüse for spraying fluids with the aid of a relative to the fluids to be sprayed hot atomizing gas, in particular steam or hot gas.

In many process plants, which are flowed through by a primary fluid, in particular by flue gas, the task is to mix a secondary fluid, in particular water, as homogeneously as possible in the primary fluid and often to evaporate by the shortest route. For this purpose, two-fluid nozzles are often used. In these two-fluid nozzles, the liquid is atomized by means of a gaseous or vaporous auxiliary. These two-fluid nozzles are characterized by a particularly fine droplet spectrum and by a very good partial load behavior. In some plants, especially in power plants and waste incineration plants, water vapor is available. Then, for cost reasons, it may make sense to Use steam as a sputtering aid, because the provision of a corresponding amount of compressed air would be associated with high investment and operating costs.

Two types of nozzles are available for atomizing with two-component nozzles, namely nozzles mixing on the inside and nozzles mixing on the outside. Examples of internally mixing and externally mixing nozzles are shown in Nasr, Jule and Bendig, Industrial Sprays and Atomization, Springer-Verlag, 2002, for example on page 24.

US Pat. No. 3,770,207 discloses a spray-drying nozzle in which an atomizing gas is divided into two concentric annular gaps. Between the two annular gaps for the atomizing gas, an annular gap for the solution to be dried is arranged. The innermost annular gap for the atomizing gas is formed by inserting a cone piece into the central outlet opening.

From the German patent application DE 195 26 404 A1 discloses a two-fluid nozzle for atomizing pasty or solids-containing fluids, such as mud, described in which the fluid to be atomized fed through a central, cylindrical channel and at the end of this channel by annularly arranged individual nozzles the atomizing gas the fluid to be atomized is injected.

From the German patent DE 85 79 24 a drying nozzle is described, in which the liquid to be atomized is atomized between an inner and an outer conical stream of gaseous sputtering aid.

The invention is intended to improve an externally mixing multicomponent nozzle for the spraying of fluids. According to the invention, an externally mixing multicomponent nozzle is provided for spraying fluids with the aid of a sputtering gas, in particular steam or hot gas, which has a housing, wherein the housing has an outlet opening for the sputtering gas, a first annular gap surrounding the outlet opening for fluid to be sprayed and a second annular gap for the atomizing gas surrounding the first annular gap and a distributor piece, the distributor piece having at least one flow channel for fluid to be sprayed from a connecting line to the first annular gap and at least one flow channel from a Zerstäubungsgasanschlussleitung to the outlet opening for atomizing gas ,

The provision of such a distributor piece within the nozzle housing ensures that the fluid to be sprayed and atomizing gas are conducted over a short path to the first annular gap or the outlet opening and the second annular gap. Alone by the provision of the manifold and the consequent short distances only a small heat transfer is achieved by spraying fluid to the atomizing gas. As a result, it can be prevented that the hot atomizing gas can already cool down and possibly even condense before it leaves the housing. As a result, a significantly better atomization effect is achieved. Preferably, the manifold is made of solid material and the flow channels are provided within the solid material.

In a further development of the invention, the housing has an annular channel for atomizing gas, which surrounds the distributor piece at least in sections. In this way, the sputtering gas from the annular channel can be guided in the second annular gap on a short path and, since advantageously the flow channel of the distributor piece for the sputtering gas emanating from the annular channel, the sputtering gas can be conducted over a short path to the outlet opening. The present invention proposes a novel nozzle concept in which the atomizing gas within a small distributor integrated into the nozzle housing is brought about a central atomization gas flow through the outlet opening as well as to an outer annular gap flow. In this distributor, the fluid to be atomized is also allocated to an annular gap which is arranged between the central flow and the outer annular gap flow of the atomizing gas. This distributor or the flow channels in the distributor are dimensioned such that it is passed by both the fluid to be atomized and the sputtering gas at a relatively high speed, so that there is hardly any time for the heat transfer. Furthermore, the surfaces leading to the heat transfer between atomizing gas and fluid are very small and the distances between the individual flow channels, which guide the cold fluid or the hot atomizing gas, are dimensioned as large as possible. Thus, by design, the internal heat transfer from the hot atomizing gas, particularly water vapor, to the fluid being atomized is minimized or limited to an advantageous value. A certain preheating of the liquid can be quite advantageous, because hereby, in the interest of a good atomization, the surface tension and the toughness of the fluid to be atomized can be reduced.

However, the invention is not exclusively concerned with the atomization quality, as can be determined in the laboratory under ideal boundary conditions on a virgin nozzle. Rather, it has to be taken into account that the atomization quality in industrial practice occasionally leads to the formation of deposits inside the nozzles or at the nozzles. Mouth suffers. This is especially true when hot water is used as the fluid to be atomized. Even if suspended solids are largely eliminated by filtration, deposit formation in the nozzle or at the nozzle mouth can often be detected by the precipitation of dissolved solids. This is especially true in those cases where a hot sputtering gas is used, which then causes the walls to heat up in contact with the service water. Limiting the heat transfer within the nozzle according to the invention can thereby also solve the problem of deposit formation in the nozzle.

In a further development of the invention, a thermal insulation is at least partially provided between the flow channel for fluid to be atomized in the manifold and the manifold.

In this way, heat transfer between the cold fluid to be atomized and the manifold heated by the hot atomizing gas can be reduced.

In a further development of the invention, the flow channel for fluid to be atomized in the distributor piece is formed at least in sections by means of a tube inserted into the distributor piece.

In this way, a heat transfer between the flow channel and the manifold can already be significantly reduced. Advantageously, an air gap is provided at least in sections between the tube and the distributor piece. An air gap insulation leads to a further, significant reduction in the heat transfer from the cold to be sprayed fluid on the manifold. In a development of the invention, the connecting line for the fluid to be atomized is designed to be double-walled at least in the connection area to the distributor piece.

In this way, a good thermal insulation, for example by an air gap, between the connecting line and the housing of the nozzle can be achieved.

In a further development of the invention, a thermal insulation layer is provided between the first annular gap and the housing and between the first annular gap and the second annular gap.

In this way, a heat transfer between the cold fluid and the hot atomizing gas can still be minimized in the annular gap area until the exit of the fluid to be atomized from the nozzle. This is of considerable advantage in the externally mixing two-substance nozzle according to the invention.

In a development of the invention, the outlet opening for the atomizing gas has the shape of a third annular gap.

The fluid to be atomized is thereby absorbed between two annular gap flows of the hot atomizing gas, so that a very good atomizing effect is achieved. The third annular gap can be formed for example by inserting a cone piece in the outlet opening.

In a further development of the invention, the boundary of the first annular gap in the flow direction is arranged in front of an outer boundary of the second annular gap. In this way, the fluid to be atomized emerges from the first annular gap and comes into contact with the sputtering gas from the second annular gap, even before the sputtering gas has left the nozzle orifice at the end of the second annular gap. As a result, the atomizing gas from the second annular gap can not yet escape laterally so that the fluid to be atomized is accelerated by the flanking gas streams before it leaves the nozzle orifice. In this way, a finer atomization of the fluid to be sprayed can be achieved.

In a further development of the invention, the boundary of the first annular gap is arranged by one to ten times the width of the first annular gap in the flow direction before the outer boundary of the second annular gap.

In a further development of the invention, at least the distributor piece of a material, in particular high alloyed stainless steel, formed with respect to brass substantially, in particular by a factor of 8, reduced thermal conductivity.

Even the provision of a material of low thermal conductivity for the distributor piece can substantially reduce a heat transfer between the fluid to be sprayed and the hot atomizing gas.

In a further development of the invention, a section of the flow channel for the hot atomizing gas located immediately upstream of the outlet opening is formed in the housing in such a way that it initially tapers in the flow direction and, after passing through a constriction, widens again up to the outlet opening.

In this way, an outlet nozzle for the atomizing gas can be formed convergent / divergent. In particular, this Tailored nozzle can be formed as a Laval nozzle, so that the hot atomizing gas then exits the outlet opening at supersonic speed.

Further features and advantages of the invention will become apparent from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. In the drawings show:

1 shows an inventive external mixing multi-component nozzle in a sectional view according to a first preferred embodiment,

2 is an enlarged detail of the multi-component nozzle of FIG. 1,

3 shows a multi-fluid nozzle according to the invention according to a second preferred embodiment and

4 shows a detail of a multi-substance nozzle according to the invention according to a third embodiment.

The sectional view of Fig. 1 shows a multi-component nozzle 1 according to the invention according to the invention. In the multi-component nozzle 1 according to the invention, the task of preventing premature Entthalpieverluste the sputtering gas by heat transfer to the liquid to be sputtered and to prevent the formation of deposits in the nozzle by temperature-dependent precipitation of dissolved at low temperature ingredients of the liquids, solved in the following manner: The via the steam supply of the multi-component nozzle 1 supplied steam stream 10 is divided into two sub-streams in a novel, small-sized manifold piece 18, which can thus be integrated into the nozzle 1. An outer partial flow 30 and a central one are produced Partial stream 28 of steam or hot atomizing gas. The outer partial flow 30 is blown through an outer annular gap 29, while the central partial flow 28 via a central nozzle 62, which ends at an outlet opening 60, is blown out. Between the central nozzle 62 with the outlet opening 60 and an outer annular gap nozzle 31, an annular gap nozzle 20 for ejecting the fluid to be sprayed, especially to be atomized water, is arranged. The approach of atomizing the liquid via a central stream and an outer annular gap stream of the atomization aid facilitates the atomization. Essential to the invention, however, is the design of the manifold 18 for distributing fluid to be sprayed and hot atomizing gas to the individual outlet openings of the nozzle first

A characteristic feature of the nozzle 1 is that the fluid to be atomized is not ejected via a central nozzle but via an annular gap. This annular gap can be made relatively large, because here a high exit velocity of the liquid is not required. The atomization is carried out according to the invention in that the liquid film is introduced between two high-speed Zerstäubungsgas- flows. As a result of the shear stress effect of these high-velocity flows, the liquid film is drawn out of the annular gap into a thin liquid lamella, which breaks up into small drops. Thus, the risk of material removal at the annular gap walls of the liquid nozzle, namely at the annular gap 21, greatly reduced and the long-term stability of the flow characteristics of such a nozzle is so far no problem. Such a nozzle but also has a very good partial load behavior, in contrast to Single-fluid nozzles according to the prior art with swirl generator in the liquid guide.

The central nozzle 62 for hot atomizing gas with the outlet opening 60 is shown in FIG. 1 in the flow direction as a convergent-divergent Nozzle executed. For example, if steam is supplied at a supercritical pressure ratio, this configuration operates as a Laval nozzle and the steam then exits the center nozzle 62 at the exit port 60 at supersonic velocity. However, it is also important that the nozzle 1 has no end surface flushed with service water. This is achieved by the very narrow edges of the annular gap 21. Thus, the problem of stalactite-like deposits does not occur here, as can be observed with end faces of nozzles according to the prior art.

Essential features of the nozzle 1 according to the invention relate to the thermal decoupling of the hot atomizing gas, especially steam, from the cold water at the nozzle connection and inside the nozzle. For this purpose, the supply line 4 for the water 5 is double-walled.

Further, through holes in the manifold 18, through which the water 5 is supplied to the annular gap 21 and the steam of the central nozzle 62 with the outlet opening 60 and the outer annular gap 29, arranged at a maximum distance from each other. In the holes 19 for the supply of water to the exit end of the nozzle 1 inner tubes 38 are used, which are on the outside, so at its beginning and end, so behind-rotated that only in narrow sections, the inner tube 38 in the bore 12 in Distributor 18 centering wall contact exists. As a result, an air-filled cavity is generated between the water-carrying inner tube 38 and the manifold 18, which serves as a thermal insulation. Furthermore, the outer jacket of the central nozzle 62 with the outlet opening 60 and the inner jacket of the annular gap nozzle 20 with the annular gap 21 with a thermally insulating layer 35, 36 occupied, so that the liquid to be atomized practically throughout its passage through the nozzle 1 into the immediate proximity to the nozzle mouth with a thermal Insulation against the nozzle housing and especially against the manifold 18 and thus also against the flow of the hot Zerstäubergases is equipped. In this way it is achieved that the liquid heats only slightly, or that the hot atomizing gas, in particular the superheated steam, suffers only small enthalpy losses due to cooling.

Of course, it is possible to apply a heat insulation on the steam-charged side of the nozzle. However, this is likely to be disproportionately expensive because the surface in contact with the vapor is much larger than is the case on the water side.

Another interesting possibility is to use at least for the manifold 18 a material with low thermal conductivity, on the other hand for the predetermined operating temperature of e.g. 300 ° C is suitable. The transition from brass to a high-alloyed stainless steel leads to a reduction in heat conduction by a factor of 8.

Fig. 1 and Fig. 2 as an enlarged detail of Fig. 1 show the nozzle 1 in a sectional view. The nozzle 1 is intended to be disposed within a channel 3 carrying a primary fluid, such as flue gas, into which a fluid to be atomized is to be injected. The channel 3 is shown only schematically by one of its terminations. The nozzle 1 is thus within the flow of the primary fluid in the channel 3.

The liquid to be atomized 5 is supplied via a connecting line 4 via a central port 17 of the nozzle housing 2 to the manifold 18 of the nozzle 1. About at least one bore 19 in the manifold 18, in which an inner tube 38 is inserted, enters the Fluids 5 in an annular space of the annular gap nozzles 20 which is bounded inwardly by a central nozzle piece 27 and outwardly by an intermediate hood 34. From this annular space, the liquid reaches the liquid outlet at the annular gap 21 by the shortest route.

The atomizing gas, e.g. Superheated steam 10, is first fed via a pipe 1 1, which leads out like the connecting line 4 from the channel 3, an annulus 23 in the nozzle housing 2. From this annular space 23 from the sputtering gas passes via at least one cutout 24 and at least one bore 25 in the manifold 18 in a central space 26 in the manifold 18. The bore 25 is dimensioned so that a defined division of the superheated steam 10 takes place in two partial streams, namely once via the bore 25 to the outlet opening 60 of the central nozzle 62 and once over the annular space of the annular nozzle 31 to the annular gap 29 at the nozzle mouth.

In the illustrated embodiment of the nozzle 1, the central nozzle piece 27 is screwed into the manifold 18 and forms the central nozzle 62 for the central steam jet 28. A flow path of the central nozzle 62 then passes to the central space 26 in the manifold 18 initially convergent in a first, conically tapered portion , This first conically tapering section is followed by a cylindrical section forming a constriction. This is then followed by a conically widening section to the outlet opening 60. As usual with Laval nozzles, the central nozzle 62 is initially convergent and then divergent and the cross-sectional dimensions of the central nozzle 62 are for dividing the vapor stream 10 onto the central nozzle 62 and onto the outer annular gap nozzle 31 with responsible. The outer vapor stream, also called annular gap steam stream 30, is first fed via the cutout 24 to the annular space of the annular gap nozzle 31 and passes from here into the outer annular gap 29. The steam thus emerges both as a central steam jet 28 from the central nozzle 62, as well as from the outer annular gap 29th

The outer annular gap 29 is formed between an outer hood 49 and the intermediate hood 34. From the outer annular gap 29 and out of the outlet opening 60, the steam exits at high speed up to high supersonic speeds, as illustrated in FIG. 2 by arrows 32, 33. Due to the interaction between the annular liquid jet emerging from the first annular gap 21, and the flanking steam jets according to the arrows 32 and 33, a droplet spray with the boundary 22, as shown in dashed lines in Fig. 1 is formed.

In many cases, the configuration described above should already cause sufficient thermal decoupling of superheated steam 10 as atomizing gas and the cold liquid 5 to be atomized. In order to improve such a thermal decoupling and to reduce a heat transfer between the fluid to be dusted 5 and the superheated steam 10, the connecting line 4 is formed double-walled for the fluid 5, in which an inner tube 37 is provided until it is connected to the manifold 18. The connecting line 4 is thus double-walled and provided with a thermally insulating air gap 44. Alternatively, the connecting lead can also be made with a graphite bush to achieve thermal insulation.

Further, the flow channel in the at least one bore 19 in the manifold 18 for the supply of water to the annular space of the annular nozzle 20 is double-walled with the inner tube 38, wherein, as explained, between the inner tube 38 and the bore 19 in the manifold 18, an air gap lies. The water-conducting annular space of the annular gap nozzle 20 is thermally insulated from the central nozzle 27 as well as the intermediate hood 34 by layers 35, 36 of suitable material. These insulating layers 35, 36 may for example consist of metal with poor thermal conductivity or of ceramic material.

In order to further reduce the heat transfer between the fluid 5 and superheated steam 10, a disk 40 made of a heat-insulating material is provided on a bottom surface 39 of the manifold 18, on which the connecting line 4 for fluid 5 is placed. As a result, a heat transfer from the fluid 5 in the connection line 4 to the manifold 18 can be substantially reduced. The disc 40 is provided with through-holes to guide fluid 5 into the at least one bore 19 and the inner tube 38 in the manifold 18, respectively.

The extent to which the measures described above are taken depends on the operating conditions of the nozzle. Already by the provision of the manifold 18 in the housing 2 of the nozzle 1, a sufficient thermal decoupling of hot steam 10 and liquid to be atomized 5 is already achieved in many cases, so that can be dispensed with such complex additional insulation measures in most cases.

The nozzle housing 2 is designed in several parts and has a first, approximately pot-shaped component 64 with the connecting line 1 1 for superheated steam and the connection 17 for the connecting line 4 for fluid 5. In the cup-shaped member 64, the manifold 18 is inserted, which is screwed onto the likewise inserted into the component 64 connecting line 4 and is supported in the radial direction via webs 66 on the inner wall of the cup-shaped member 64. Between the webs 66, the recesses 24 are provided, via the superheated steam 10 in the Flow channel formed by the bore 25 in the manifold 18 and to the outer annular gap 31 passes.

On the cup-shaped member 64, the outer hood 49 is screwed. Within the outer hood 49, the intermediate hood 34 is arranged, which is screwed onto the distributor piece 18. Between the outer hood 49 and the intermediate hood 34, the outer annular gap nozzle 31 is thus formed for hot atomizing gas, which ends at the nozzle orifice at the outer annular gap 29.

Within the intermediate hood 34, the central nozzle piece 27 is screwed into the distributor piece 18. Between the central nozzle piece 27 and the intermediate hood 34, the annular gap nozzle 20 is formed for fluid to be atomized, which ends at the nozzle mouth at the annular gap 21. As already described, an annular gap nozzle 20 on one side bounding outside of the central nozzle piece 27 is partially covered with an insulating layer 35. Only immediately upstream of the annular gap 21 no insulating layer 35 is more provided in order to form the annular gap 21 can narrow.

An inside of the intermediate hood 34, which limits the annular gap nozzle 20 to the outside, is also partially covered with an insulating layer 36. Only immediately upstream of the annular gap 21 no insulating layer 36 is provided.

The nozzle 1 according to the invention can be seen to have a very compact design and, in particular, the hot steam 10 is divided into the central nozzle 62 and the outer annular nozzle 31 within the housing 2 of the nozzle 1 over a short path. The flow channel for superheated steam in the manifold 18, formed by the bore 25, passes through the hot steam to the central nozzle 62 is at an angle to the also provided in the manifold 18 flow channel for fluid to be atomized 5, formed by the bore 19 and the inner tube 38, respectively. The flow channel for superheated steam and the flow channel for fluid are thus arranged crosswise within the distributor piece 18. In the illustrated embodiment, an angle of about 45 ° between the central longitudinal axes of the flow channel for superheated steam and the flow channel for fluid.

The manifold 18 is made of high-alloy stainless steel, which has a low thermal conductivity. In comparison with conventional brass nozzles, this already achieves a heat transfer from the superheated steam 10 to the cold fluid 5 which is reduced by a factor of about 8.

The inner tube 38, which is inserted into the bore 19 of the manifold 18, forms a flow channel for the fluid 5 through the manifold 18. The inner tube 38 is designed as a rotating part and rests only in the areas 68, 70 on the inner wall of the bore 19 , Outside the regions 68, 70 illustrated in FIG. 1 in black, an insulating air gap 72 is located between the inner tube 38 and the distributor piece 18.

Fig. 2 shows the nozzle mouth with the outlet opening 60 of the nozzle 1 in an enlarged view. It can be seen that the outlet opening 60 of the central nozzle 62, the end of the annular gap 21 of the annular gap nozzle 20 and the annular gap 29 defining the outlet of the annular gap nozzle 31 are located exactly at the same height transversely to the flow direction. Only outside of the nozzle 1 does this result in a mixing of the superheated steam jets from the annular nozzle 31 and the central nozzle 62 with the annular gap flow of fluid to be atomized from the annular nozzle 20. The representation of FIG. 3 shows a further multi-substance nozzle 80 according to the invention according to a second preferred embodiment. The multi-material nozzle 80 is constructed in many parts identical to the multi-component nozzle 1 in FIG. 1, so that only the features different from the nozzle 1 in FIG. 1 are explained.

As can be seen in Fig. 3, in the manifold 18, a central body 41 is screwed, which extends through a central nozzle 82 for superheated steam through. The central body 41 is thus completely flowed around by the central chamber 26 in the manifold 18 to hot steam. In the region of the outlet opening 60 of the central body is designed in the form of a widening cone 42, so that the outlet opening 60 is annular and an inner annular gap 43 for the exit of the bore 25 supplied portion of the superheated steam 10 is formed. The annular stream of fluid 5 to be atomized is thus trapped between two equally hot vapor streams.

By providing the cone 42, the central steam also flows out via the annular gap 43. In this case, however, the central cone 42 only flows around hot steam, which is largely solids-free, so that there is no relevant deposit formation risk on the cone 42. By the cone 42, the steam consumption of the nozzle 80 with respect to the nozzle 1 can still be lowered slightly without this having a negative effect on the atomization quality. Even with the nozzle 80 with the central cone 42, the central nozzle 82 can be designed as a Laval nozzle. In the illustration of FIG. 3, however, this is not the case. In order to form the central nozzle 82 as a Laval nozzle, the flow cross-section of the annular gap between the central body 41 and the outlet part of the central nozzle 82 to the nozzle mouth must have a divergent course. The illustration of FIG. 4 shows sections of a multi-substance nozzle 90 according to the invention in accordance with a third preferred embodiment. The nozzle 90 is formed in many parts identical to the nozzle 1 in Fig. 1, so that only the deviating from the nozzle 1 features are described.

The nozzle 90 has an outer hood 92, which is extended relative to the outer hood 49 of the nozzle 1. As a result, the outlet opening 60 of the central nozzle 62 and the annular gap 21 of the annular gap nozzle 20 for the fluid to be atomized are set back relative to the nozzle mouth. The nozzle mouth is formed in this case by the downstream end of the outer hood 92. In the case of the nozzle 90, contact between the annular liquid flow from the annular gap 21 and the hot gas flows from the outlet opening 60 and the annular gap 29 occurs even within the nozzle housing. Already within the nozzle housing, albeit close to the nozzle mouth, this creates a free liquid lamella, which is no longer slowed down by wall friction, but is greatly accelerated by the flanking high-speed streams of atomizing aids, for example superheated steam. Implementing this already within the nozzle 90 offers the advantage that the streams of the atomization aid and especially the hot gas flow from the annular gap 29 can not yet escape laterally, as is the case after leaving the nozzle. In this way, an even finer atomization of the liquid is effected. The return of the outlet of the liquid nozzle with respect to the position of the nozzle orifice is advantageously one to ten times the width of the annular gap 21 of the annular gap nozzle 20 for the liquid at the nozzle orifice. In the illustrated, merely exemplary drawing, the width of the annular gap 21 for the liquid is about 1 mm and this annular gap is compared to the nozzle mouth by about 5mm, so the fivefold width of the annular gap 21, reset. The invention thus provides an externally mixing multi-substance nozzle in which a minimal internal heat transfer between the fluid to be sprayed and the atomizing gas is realized. The division of the liquid to be atomized and the atomizing gas is carried out in a manifold which is integrated in the nozzle body or the nozzle housing. By this design according to the invention it is achieved that the heat transfer from the hot atomizing gas to the liquid to be atomized within the nozzle, especially within the nozzle housing is minimized or limited to an advantageous value. The inventive external mixing multi-substance nozzles are used in flue gas ducts or in flue gas purification plants in power plants or in the cement industry.

Claims

claims

External mixing multi-component nozzle for spraying fluids with the aid of a relatively hot to the sprayed fluids sputtering gas, in particular steam or hot gas, with a housing (2), wherein the housing (2) has an outlet opening (60) for the sputtering gas, the outlet opening (60 ) surrounding the first annular gap (21) for the fluid to be sprayed and a first annular gap (21) surrounding the second annular gap (29) for the atomizing gas and a manifold (18), wherein the manifold (18) at least one flow channel for fluid to be sprayed from a connecting line (4) to the first annular gap (21) and at least one flow channel of a Zerstäubungsgasanschlussleitung (1 1) to the outlet opening (60) for atomizing gas.

Externally mixing multi-component nozzle according to claim 1, characterized in that the housing (2) has an annular channel (23) for atomizing gas, which surrounds the distributor piece (18) at least in sections.

Externally mixing multi-component nozzle according to claim 2, characterized in that the flow channel of the distributor piece (18) for the atomizing gas proceeds from the annular channel (23).

Externally mixing multi-component nozzle according to one of the preceding claims, characterized in that at least in sections a thermal insulation is provided between the flow channel for the fluid to be atomized and the distributor piece (18).

5. external mixing multi-component nozzle according to claim 4, characterized in that the flow channel for fluid to be atomized at least in sections by means of a in the manifold (18) inserted tube (38) is formed.

6. Externally mixing multi-component nozzle according to claim 5, characterized in that between the tube (38) and the distributor piece (18) at least in sections, an air gap (72) is provided.

7. Externally mixing Mehrstoffdüse according to any one of the preceding claims, characterized in that the connecting line (4) is designed to be atomized fluid at least in the connecting region to the manifold (18) double-walled.

8. Externally mixing two-component nozzle according to one of the preceding claims, characterized in that between the first annular gap (21) and the housing (2) and between the first annular gap (21) and the second annular gap (29) a thermal insulating layer (35, 36) is provided.

9. Externally mixing multi-component nozzle according to one of the preceding claims, characterized in that the outlet opening (60) for sputtering gas has the shape of a third annular gap.

10. Außenmischende Mehrstoffdüse according to any one of the preceding claims, characterized in that the boundary of the first annular gap (21) seen in the flow direction in front of an outer boundary of the second annular gap (29) is arranged.

1 1. Externally mixing Mehrstoffdüse according to claim 10, characterized in that the boundary of the first annular gap (21) by one to ten times the width of the first annular gap seen in the flow direction in front of the outer boundary of the second annular gap (29) is arranged.

12. Externally mixing multi-component nozzle according to one of the preceding claims, characterized in that at least the distributor piece (18) made of a material, in particular highly alloyed stainless steel, with respect to brass substantially, in particular by a factor of 8, reduced thermal conductivity is formed.

13. Externally mixing Mehrstoffdüse according to any one of the preceding claims, characterized in that a immediately upstream of the outlet opening (60) lying portion of the flow channel for atomizing gas in the housing (2) in the flow direction initially tapers and after passing through a constriction to the outlet opening (60 ) expanded again.