EP0914869B1 - Nozzle with constant spray characteristics over a large size range - Google Patents

Abstract

The jet (10) has at least three concentric flow channels each leading to a gap-type mouth aperture. One mouth gap (32) spraying a liquid is surrounded on both sides by other gaps (30, 34) for gas output. The gap width (42) of the mouth gap for spraying the liquid is 0.22-2.2 mm wide. The gap width (40, 44) of the gap for gas output is 0.3-2.3 mm. The ratio between the spray mouth gap width and the length of the surrounding gap is between 1:50 and 1:5000.

Description

The invention relates to a multi-component atomizing nozzle with at least three concentric, each with a slit-shaped mouth opening leading flow channels, with a mouth gap for spraying a liquid on both sides of one Mouth gap is surrounded for the escape of a gas.

Such an atomizing nozzle is known from DE-PS 857 924.

In this atomizing nozzle there are annular flow channels provided by several concentrically nested Pipes are formed. Taper in the area of the mouth opening the flow channels radially inward.

A flow channel for spraying a liquid is on both sides surrounded by channels for the passage of air.

A widely used area of application for a multi-component atomizing nozzle according to the present application in being a particulate good with the liquid to be sprayed to treat.

A treatment process consists, for example, of a particulate one Easy to granulate. The goal is to fine fine particles agglomerate larger particles. An area of application for such Granules is the pharmaceutical industry in which almost dust-fine particles to more manageable granulate particles should be agglomerated.

In another area of application, namely coating, the sprayed liquid a superficial coating on the form coating material.

In these areas of application, nozzle assemblies have proven to be advantageous proven, as known for example from DE 41 10 127 A1 are. Linear gap channels are provided there. both sides a central outlet channel for the liquid are slit-shaped Mouth openings are provided for a gaseous medium. By appropriately aligning these gas flows can be achieved that the liquid after it becomes the slit-shaped Has left the mouth opening, sprayed into a mist is not a long "wet" jet. Around the spray Conditioning even further is in some areas of application planned to provide further gas outlet openings, for example a specially conditioned gas flow around the Spray mist is guided around, for which the technical term "Microclimate" has established. This microclimate ensures, for example, that the spray does not dry prematurely, undesirable warmed or cooled (e.g. hot-melt coating), but in the consistency required on a case-by-case basis It hits well.

Another widely used nozzle type in this technology is known from DE 38 06 537 A1.

These nozzles are tubular and have a central one cylindrical channel with a circular outlet opening for the liquid on. This central channel is from surrounded by an annular channel through which the spray air is led that is, the central cylindrical beam is ring-shaped surrounds, which then results in a conical spray.

In practical use, it was found that certain Operating sizes and certain operating parameters for a certain Scope with satisfactory results a nozzle of a certain size can be achieved.

Such specific operating variables are, for example, the gap width and the length of the gap through which the liquid and the Escaping gas flows. The operating parameters of pressure and throughput can be varied with a specific nozzle size.

One problem is the so-called "scaling-up", i.e. when one of an apparatus of a certain size, which with a certain number of nozzles of a certain size is transferred to larger apparatus.

The procedure adopted so far was that with larger apparatuses, a larger number of accordingly identical nozzles are used, leading to the corresponding construction costs and especially with the nozzles the numerous additional connections to supply them Nozzles with the media leads.

Try to use a certain type of nozzle with a higher one Operating throughput, for example, of liquid to be sprayed, to treat more particulate matter in a larger apparatus to fail if, for example, the throughput and the pressure of the liquid passed through the nozzle become so large that this amount of liquid no longer becomes one finely divided mist can be sprayed. Expressed differently, arise at high pressures and high throughputs long "wet" tongues or flames, ie areas in which the Liquid is still relatively compact and not sprayed.

Considering the widespread use of such nozzles in a fluidized bed apparatus, in the bottom of which such nozzles are installed are, the swirled good hovers near the Mouth openings of the nozzles or just above, so that long "Wet" flames or tongues to wet the patient to be treated Good results in the area of the nozzle and no uniform treatment can be achieved in the entire fluidized bed.

Therefore, nozzles of a certain structural size and one certain construction when scaling up in larger numbers used to increase the throughput accordingly to achieve spraying liquid.

It is therefore an object of the present invention to remedy this to create and with a nozzle type of the type mentioned with concentric channels to enable scaling-up at which the number of nozzles does not have to be increased significantly and a spray characteristic is achieved which, within certain Bandwidths, is constant.

According to the invention the object is achieved in that the gap width of the mouth gap for spraying the liquid the mouth opening is in the range of 0.2 mm to 2.2 mm that the gap width of the mouth gap for the exit of the gases at the Mouth opening is in each case in the range from 0.3 mm to 2.3 mm, and that the ratio between the gap width of the orifice gap for spraying the liquid and the extensive Gap length of this gap in the range from 1:50 to 1: 5,000 lies.

By following these parameters it is possible to use different nozzles Sizes and thus different throughput quantities to build, but still have the same spray characteristics. There is a nozzle with a certain diameter of the mouth opening for the passage of the liquid to be sprayed before, the gap width can range from 0.2 mm to 2.2 mm can be varied, with wider gaps while remaining the same Spray characteristics allow larger throughputs. It is necessary, because, for example, larger equipment has to be supplied, pumping even more liquid per unit time through the nozzle, so a larger diameter nozzle can be provided, ie with a larger gap length, but the gap width is still in the range of 0.2 mm to 2.2 mm. Thereby is the volume available to deliver the liquid enlarged accordingly, due to the given boundary conditions the spray characteristics of the nozzle are retained. spray characteristics means that even with a much larger one Nozzle with higher throughput rates constant spray mist conditions can be achieved like with a much smaller nozzle, thus a good that is swirled through this area, so just as evenly and with about the same amount per Volume or area unit with the liquid to be sprayed is applied. This spray characteristic remains in the Ratio range of gap width to gap length from 1:50 to 1: 5,000 received.

This knowledge based on intensive research solves So the basic principle, with large throughputs several To provide nozzles, but enables a real scaling-up, i.e. if the apparatus is enlarged with the same or not slightly increased number of nozzles while maintaining treat the spray characteristics larger amounts per time to be able to.

If you go to the example mentioned in the pharmaceutical Back in the granulating industry finest powdered pharmaceuticals goes, and has one for a particular Batch size, for example in an apparatus with a capacity of 100 kg, with a certain number and one certain size of nozzles thus a certain spray characteristic achieved an optimal granulation result, is a scaling up to a treatment amount of 1,000 kg in a corresponding manner to carry out larger equipment without problems, there, in compliance with the given parameters, the same Preserve spray characteristics even with a much larger nozzle remains, consequently also the corresponding treatment result.

The task is thus completely solved.

In a further embodiment of the invention, the gap width is of the mouth gap for spraying the liquid in the Range from 0.8 mm to 1.6 mm.

It was found that with these gap widths the usual ones Treatment methods, namely granulating, drying and coating, especially in the pharmaceutical industry, in scaling-up can be carried out, and at the same time an equally good treatment result even with larger batches with an approx same number of nozzles can be achieved.

In a further embodiment of the invention, the gap width is of the mouth gap for spraying the liquid about 1.2 mm.

Numerous studies have found that this is a is the optimal gap width value, for example in the pharmaceutical Industry-standard liquids with constant Spray characteristics in different scaling-up levels to be able to.

In a further embodiment of the invention, the gap width is of the mouth gaps for the gas to exit on both sides of the Gap for spraying the liquid in the range of 0.9 mm up to 1.9 mm.

As previously mentioned, this area opens with the usual ones Treatment methods include scaling up in large steps Maintaining a very constant spray characteristic.

In a special embodiment of the invention Gap width of the mouth gaps for the gas to exit on both sides of the gap for spraying the liquid at about 1.3 mm.

This gap width has changed in the previously mentioned areas of granulating, drying and coating, especially in the pharmaceutical industry, as an optimal value turns out which is a very large-scale scaling-up with consistently excellent Spray characteristic enables.

In a further embodiment of the invention, in the further concentric flow channels that are radially inside and / or radially outside of the at least three concentric flow channels are arranged, the gap width of the mouth gap of these further concentric flow channels in the area of Mouth opening in the range from 0.5 mm to 3.5 mm.

This selection range also enables nozzles with a conditioning "microclimate", a scaling-up with constant spray characteristics.

This retention of a very specific spray characteristic with conditioning microclimate is especially in gap widths the other concentric flow channels in the area from 2.0 to 3.0 mm and in particular with gap widths of approximately 2.5 mm achieved.

The narrower the bandwidths are and the more specific they are Operating parameters, for example the pressure with which the media through the channels, has specified, the easier scaling-up is possible under the specified conditions.

This not only has the advantage that contrary to what was mentioned at the beginning State of the art in a scaling-up is now not numerous additional connections to the numerous additional Nozzles can be brought up, but essentially with the same number of nozzles or possibly due to geometric necessities only worked with a slightly higher number of nozzles must become. In addition, the often tedious are eliminated and especially lengthy investigations and trials with a scaling-up. The data previously obtained from a very specific batch size, a certain nozzle size and have been found at certain operating parameters, previously had to be completely redefined in a scaling-up, to get back to the same coating result with a larger one Batch as with the smaller batch. Now this will be much simplified.

The invention is independent of whether it is strict annular flow channels, oval or elliptical flow channels is acting, whether they are continuously ring-shaped or only spray over partial areas, and is also independent of whether the spray direction is exactly along the flow channel axis runs or directed out of this. Because it was through intensive research found that even with different Constructions as described below in compliance with the gap width and gap length parameters consistently good treatment results with a scaling-up can be achieved.

It is understood that the above and those below Features not yet to be explained in the specified Combination, but also in other combinations or can be used alone without the scope of the present Leaving invention.

Fig. 1

einen Längsschnitt eines ersten Ausführungsbeispiels einer erfindungsgemäßen Mehrstoffzerstäubungsdüse mit insgesamt drei konzentrischen Strömungskanälen;

Fig. 2

einen Schnitt längs der Linie II-II in Fig. 1 im Bereich der Mündungsöffnung, wobei ein in Fig. 1 mit einem Kreis umgrenzter Bereich in stark vergrößertem Maßstab zusätzlich dargestellt ist;

Fig. 3

eine der Fig. 2 vergleichbare Schnittdarstellung einer entsprechend größeren Düse mit gleicher Sprühcharakteristik wie die in Fig. 1 und 2 dargestellte Düse, wobei in Fig. 3 ein mit einem Kreis umgrenzter Bereich ebenfalls in größerem Maßstab zu Erläuterungszwecken dargestellt ist;

Fig. 4

eine stark schematisierte Seitenansicht eines weiteren Ausführungsbeispiels einer Mehrstoffzerstäubungsdüse mit fünf Strömungskanälen und einer aus der Mittellängsachse der Düse herausgerichteten Sprührichtung; und

Fig. 5

eine stark vergrößerte Schnittdarstellung der Mündungsöffnung der Düse von Fig. 4.

The invention is described and explained in more detail below on the basis of a few selected exemplary embodiments in conjunction with the accompanying drawings. Show it:

Fig. 1

a longitudinal section of a first embodiment of a multi-substance atomizing nozzle according to the invention with a total of three concentric flow channels;

Fig. 2

2 shows a section along the line II-II in FIG. 1 in the region of the mouth opening, a region delimited by a circle in FIG. 1 being additionally shown on a greatly enlarged scale;

Fig. 3

2 shows a sectional illustration comparable to FIG. 2 of a correspondingly larger nozzle with the same spray characteristic as the nozzle shown in FIGS. 1 and 2, FIG. 3 also showing a region delimited by a circle on a larger scale for explanatory purposes;

Fig. 4

a highly schematic side view of another embodiment of a multi-substance atomizing nozzle with five flow channels and a spray direction directed out of the central longitudinal axis of the nozzle; and

Fig. 5

a greatly enlarged sectional view of the mouth of the nozzle of FIG. 4th

A multi-substance atomizing nozzle shown in FIGS. 1 and 2 is provided with the reference number 10 in its entirety.

The nozzle 10 consists of four coaxially pushed tubes 12, 14, 16 and 18.

The two outer tubes 16 and 18 are at the inflow end provided with widenings, so that here non-specified inflow chambers are formed, the via connecting pieces 20 and 22 with through the nozzle 10 spraying media are supplied.

Between the innermost tube 12 and the adjacent radially outer one Tube 14 is formed a channel 24 which, as in the enlarged 2 clearly visible, in an annular mouth gap 30 in the region of the mouth opening the nozzle 10 opens.

Is between the tube 14 and the radially next outer tube 16 another channel 26 created in an annular Mouth gap 32 opens, as can be seen from FIG. 2.

Between the tube 16 and the outermost tube 18 is another Channel 28 created in an annular mouth gap 34th opens in the area of the mouth opening.

The inner channel 24 and the outer channel 28 are over the connecting piece 22 with a gaseous medium called Spray air SL supplies, like that in particular from the sectional view 1 can be seen.

The middle channel 26 is connected to the connecting piece 20 with the to be sprayed liquid SF supplied.

Now the two media are spray air SL and spray liquid SF conveyed through the nozzle 10, so passes through the mouth gap 32 the liquid that flows through the both sides of the Mouth gaps 30 and 34 spray air emerging to a fine Mist is sprayed, as indicated by the arrows in Fig. 1 is.

The innermost tube 12 is closed by a plug 36, so that a spray cone ring is created as he is indicated in Fig. 1 by the dashed lines.

This spray cone now has a very specific characteristic, i.e. the finely sprayed liquid particles move with a certain characteristic, i.e. in a certain Direction and a specific density distribution from the nozzle mouth path.

A larger amount of liquid is now to be conveyed through a nozzle 10 be so it is not possible to use the spray liquid with an arbitrarily higher pressure and thus with a higher To promote throughput through channel 26, because then a Relatively long "wet" tongue or flame on spray liquid escaping SF arise before, if at all, through the spray air can be sprayed into a mist. There one such a "wet" tongue take up a length of several centimeters can, but in the centimeter range in front of the nozzle mouth the goods to be treated already existed, none would uniform treatment result can be achieved, yes not at all with the desired spray characteristics.

In Fig. 3, a nozzle 50 is now shown, which also consists of four nested tubes 52, 54, 56 and 58 constructed accordingly, corresponding result at the mouth of the nozzle 50 Muzzle splits 60, 62 and 64. The diameter and the Materials of the tubes 52, 54, 56 and 58 is now chosen so that the gap width 72 of the mouth gap 62 through which the liquid occurs, approximately the gap width 42 of the mouth gap 32 corresponds to the nozzle 10. The gap widths are the same 70 and 74 of the mouth gaps 60 and 64 of the nozzle 50 approximately same as the gap widths 40 and 44 of the mouth gaps 30 and 34 of the nozzle 10, ie the areas through which the spray air exits.

From the enlarged outlined areas of FIGS. 2 and 3 obvious that under the same operating conditions the same Spray characteristics, i.e. a corresponding distribution of the sprayed particles can be achieved independently whether you are conveying through the nozzle 2 or through the nozzle 3. Due to the fact that the size of the mouth gaps 60, 62 and 64 but is much larger, can be seen as a whole the nozzle 50 a significantly higher amount of spray liquid SF or spray air SL are promoted per unit of time, thus with a nozzle 50 with a scaling-up with constant spray characteristics more material can be sprayed.

Not just the microscopic spray characteristics but also the macroscopic spray characteristics, except that the nozzle 50 has a larger diameter changes not as long as you look in the dimensioning rules of the relationship between the gap width 42 or 72 and the circumferential gap length remains between 1:50 and 1: 5,000.

4 and 5 is another embodiment of a nozzle 80, which consists of six tubes 82 pushed into one another, 84, 86, 88, 90 and 92 is constructed. In the area of the mouth end are six molded on tubes 82, 84, 86, 88, 90 and 92 Rings 94, 96, 98, 100, 102 and 104 put on, which ensure that the channels created between the pipes in the area the mouth opening from the central longitudinal axis 130 of the nozzle 80 be deflected sideways out.

Nevertheless, there are 80 ring-shaped mouth gaps in the nozzle 110, 112, 114, 116, 118 available.

The mouth gap 114, which formed between the ring 98 and 100 has a gap width 124 through this gap the liquid is sprayed.

On both sides of the mouth gap 114 are two ring-shaped mouth gaps 112, 116 present between the rings 100, 102 or 96 and 98 are formed and their gap widths 122 and 126 are identical and slightly larger than the gap width 124.

The spray air escaping through the mouth gaps 112 and 116 atomizes the liquid emerging through the orifice 114 to a fine spray 131, as indicated in Fig. 4 and which is laterally directed out of the central longitudinal axis 130 is.

Through the innermost opening gap 110 or the outermost opening gap 118 between the rings 94 and 96 or the rings 102 and 104 a gaseous medium is now carried, which for a so-called microclimate 133 ensures that the spray 131st is around and conditioned accordingly, like which is indicated in Fig. 4 by the arrows. The microclimate 133 ensures, for example, that the media of the spray 131 do not cool down too quickly, so they are affected by the microclimate kept at temperature.

It can be seen from FIG. 5 that the gap widths 128 and 120 the mouth gaps 110 and 118 are slightly larger than the gap widths the other muzzle.

For example, the gap width 124 is approximately 1.2 mm, the gap widths 122 and 126 about 1.3 mm and the gap widths 120 and 128 about 2.5 mm.

The circumferential gap length of the gap 114 through which the spray liquid occurs is about 408 mm, so a ratio between gap width 124 and gap length in the range of 1: 340 is present.

If a scaling-up is now to be carried out, we will do so accordingly pipes with larger diameters, but with roughly the same radial distances used, so that then again Spray characteristics are retained.

In contrast to the nozzle 110, the stopper closes 142 not the inner channel surrounded by the inner tube 82 completely, so that even through the interior of the nozzle 80 a medium can pass through, for example process air or a mixture from process air and a solid, which additionally through the nozzle 80 is to be sprayed.

Claims (8)

1. Multi-substance diffusing nozzle having at least three concentric flow channels (24, 26, 28) each leading to a gap-like discharge opening, a discharge gap (32, 62, 114) for atomizing a liquid (SF) being surrounded on either side by a discharge gap (30, 34; 60, 64; 112, 116) for the escape of a gas (SL), characterized in that the gap width (42, 72, 174) of the discharge gap for atomizing the liquid at the discharge opening is in the range from 0.2 mm to 2.2 mm; the gap width (40, 44; 70, 74; 122, 126) of the discharge gaps (30, 34; 60, 64; 112, 116) for escaping of the gases at the discharge opening is in each case in the range from 0.3 mm to 2.3 mm; and the ratio between the gap width (42, 72, 124) of the discharge gap for atomizing the liquid (SL) and the circumferential gap length of that gap is in the range from 1:50 to 1:5000.
2. Multi-substance diffusing nozzle of claim 1, characterized in that the gap width (42, 72, 124) of the discharge gap for atomizing the liquid (SF) is in the range from 0.8 mm to 1.6 mm.
3. Multi-substance diffusing nozzle of claims 1 or 2, characterized in that the gap width (42, 72, 124) of the discharge gap for atomizing the liquid (SF) is approximately 1.2 mm.
4. Multi-substance diffusing nozzle of anyone of claims 1 through 3, characterized in that the gap width (40, 44; 70, 74; 122, 126) of the discharge gaps for escaping of the gas (SL) on either side of the gap for atomizing the liquid is in the range from 0.9 mm to 1.9 mm.
5. Multi-substance diffusing nozzle of anyone of claims 1 through 4, characterized in that the gap width (40, 44; 70, 74; 122, 126) of the discharge gaps for escaping of the gas (SL) on either side of the gap for atomizing the liquid is approximately 1.3 mm.
6. Multi-substance diffusing nozzle of anyone of claims 1 through 5, characterized in that further concentric flow channels which are arranged radially inside and/or radially outside the at least three concentric flow channels are provided, the gap width (120, 128) of the discharge gap (110, 118) of those further concentric flow channels at the discharge opening is in the range from 0.5 mm to 3.5 mm.
7. Multi-substance diffusing nozzle of claim 6, characterized in that the gap width (120, 128) of the further concentric flow channels is in the range from 2.0 to 3.0 mm.
8. Multi-substance diffusing nozzle of claims 6 or 7, characterized in that the gap width (120, 128) of the further concentric flow channel is approximately 2.5 mm.

Images