DE2237021A1 - DEVICE FOR SPRAYING LIQUIDS - Google Patents

Description

PATENT LAWYERS

DR. ERNST STURM

DR. HORST REINHARD

DIPL.-ING. KARL-JÜRGEN KREUTZ

8000 Munich 40, Leopoldstrasse 20 / IV Telephone: (0811) 3964 51

Wire: Isarpatent

Bank: Deutsche Bank AG Munich 21/14171

Postal check: Munich 9756

Date July 14, 1972

Applicant: Dipl.-Agr. Erhard Grolitsch

Graz / Austria
Strauchgasse 23

Device for atomizing liquids

The invention relates to a gate direction for atomizing liquid to pasty substances on the inner wall of a its axis of symmetry rotating shell.

Such a device is already from the German patents 559 141 and 733 017 become known. It is the shell in the form of a relatively flat or wide open rotating bell formed whose opening edge either vertically downwards or in the patent

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733 017 also points vertically upwards. The liquid will while from a feed tank in the central part of the rotating Bell over the edge bores depressurized over the tüifang distributed where it runs along the inner wall to the outside.

The liquid forms a thin layer on the inner wall, which experiences a gradually increasing pulling force and finally tangential at the edge of the opening at right angles or thrown off at approximately right angles to the axis of rotation will. In doing so, the »layer becomes more towards the edge of the opening and more diluted. The layer thickness at the edge of the opening corresponds to the fineness of the particles thrown off.

According to German patent specification 733 017; an atomizing ring is provided coaxially on this relatively flat bell between the hub and the opening edge. The liquid is to be thrown towards the outer zone of the bell via this atomizing ring. This is to ensure that the flowing adhesion between the liquid and the surface of the bell that occurs during rapid rotation of the bell is temporarily interrupted after a certain length and hits the surface of the bell again before the outer edge, whereby the 'liquid film on the bell is increasingly thinner and thus more evenly distributed in the radial direction. At the. The liquid particles should then be thrown off under the effect of centrifugal force with a strength corresponding to the thickness of the film on the outer edge of the opening. The ζ wiped-off Hing

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thus serves to bridge a certain radial distance that is flown through at relatively high speed; on the greater volume then reached, the liquid is then pulled apart again to a correspondingly thinner piIm.

The present invention also works with a rotating one ochale, but it is based on a completely different concept or a completely different mode of action. And should In the invention, the liquid is not pulled apart into a fine film and finally thrown off at the edge of the opening will; rather, the invention is based on the principle of reflection in the parabolic mirror.

The invention is based on the object of a device to create the type specified, in which the liquid in the form of jets on the inner wall of the rotating concave body, in particular a paraboloid and reflected on this like the parabolic mirror each impacting particle due to the higher circumferential speed at the point of impact in a large number smaller particles are sheared, ground or torn.

According to the invention, the solution is that the shell has the shape of a paraboloid of eotation, in which the axis of rotation is at a distance from and parallel to the axis of the parabola and that is coaxial with the shell and about the same axis

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rotatable a cylinder with a number of eccentric, essentially Coaxial bores are provided for supplying the liquid under pressure, the bores on the in the shell protruding end face of the cylinder open out at the focal point of the respective associated parabola. (The corresponding parabola is determined by the intersection of the paraboloid with one through the ßotationsachse and the relevant supply channel walking plane.)

The liquid is first divided into a corresponding number of partial flows through the bores.

The fluid emerges from the bores with an axial velocity component corresponding to the pressure; this A radial component corresponding to the speed of the cylinder is superimposed on the axial component, so that it closes overall results in an exit cone of the liquid. The liquid is therefore already in particles in the exit cone divided, essentially in the form of rays emanating from the respective focal point (initial atomization or coarse atomization). The opening angle of this outlet cone can be regulated by the pressure and the speed. The speed is up to approx. 25,000 rev./pline, the pressure up to approx. 30 atm. With the appropriate high impact velocity and curvature of the shell, each impacting liquid particle becomes according to the law: angle of incidence »angle of reflection reflected like a parabolic mirror and divided in the process (^ Jeit-

or fine atomization).

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Already "occurs when reflecting on a stationary wall a certain atomization. In the invention, however, the reflective surface rotates. It affects every epidemic that hits it thus a corresponding peripheral speed for each. Particles are given a corresponding angular momentum. Each particle is largely torn and ground up. Since the opening angle of the exit cone is adjustable, is also the zone in which the exit cone mainly on the concave Body impacts, adjustable, with which also the impact on impact effective circumferential speed and thus the respectively desired atomizing effect can be adjusted. "With a simple one According to the invention, the shell is seated in a rotationally fixed manner on the circumference of the cylinder protruding into it; the shell and the So cylinders rotate in the same direction at the same speed. But you can also provide that the shell and the cylinder at different speeds or in opposite directions are rotatable to each other. With correspondingly lower absolute speeds, correspondingly higher speeds are achieved Relative speeds.

The ratio between the cross-section of the feed line of the substance to be atomized and the sum of the free bore cross-sections in the rotating cylinder. The smaller the sum of the bore cross-sections in the rotary cylinder compared to the cross-section the feed line, the higher the exit velocities from the rotary cylinder can be obtained. Also the

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The free cross-section of the individual holes is also decisive for the effect. For this purpose, it is proposed that the .Bbohrungen first taper conically in the cylinder from its rear end and then again towards the front end surface expand conically.

This i'orm of the bores reduces the flow resistance on the inlet side and favors the primary dissolution on the exit side dusting effect through the formation of a beam interruption, üuch with the cross-sectional shape of the bores, the -e'orm des atomized good. The holes can be round or oval, but also angular, e.g. B. rectangular, be square, triangular. In a simple design, the holes go axially to the rear of the otirnseite Cylinder through, whereby the rotating cylinder with its back-sided The end protrudes into a pressure cylinder into which the liquid is introduced under pressure. The holes are to be arranged peripherally in the rotation cylinder. Finally, the concave body and the cylinder can be surrounded by a heating device be, whereby the respective appropriate temperatures, and on the one hand, the intrinsic temperature of the liquid and, on the other hand, the temperature at the point of impact must be regulated.

Finally, there is another, structurally very simplified Construction of the type mentioned above, which is characterized in that for supplying the liquid in i'orm one Exit cone to the shell is not a rotating cylinder, but

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a stationary nozzle with a multitude of inclined, a hollow cone circumscribing bores or lines - for example in the manner of a single-row shower nozzle - are provided is.

The device according to the invention can be used for atomization tasks can be used in a wide variety of ways. Outstanding results were achieved using a device according to the invention for converting a liquid to pasty fat or fat mixture into a free-flowing, stable, finely crystalline fat powder, the mixture being known per se Melted way, at different viscosity grades by means of the device according to the invention is sprayed and thereby exposed to a cold shock, in which the sprayed fat particles freeze. This results in very regular, im; essentially smooth, spherical particles. By setting The fineness of the particles can be easily regulated in terms of pressure and rotation speed, and the particles obtained are only narrow Lose boundaries in their size. With a rough or even However, other bizarre particle shapes can also be obtained on the ribbed surface of the concave body and the crushing effect can be increased.

In general, a pressure of up to JO is sufficient for atomization atü and a speed of the atomizing device up to 25,000 rpm; both should be infinitely variable. High viscosity

Naturally, pollutants require a higher pressure or higher Ifrehzahl.

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"Going beyond the traditional atomization effect can with the inventive device also a fine to Coarse-grained powder is produced in which a central particle is coated with a second substance. In In a particular embodiment, the invention also relates to a method for converting a two-component mixture into a powder or semolina, one substance component being encased by another substance component. Play here the surface properties of the individual substances play a role. Most of the time, the part to be coated will be a solid material, with the casing or the jacket having to fulfill a protective task.

For example, a suspension of solids in more or more less thin liquid fat or liquid gelatin, among other things, atomized by the device described, whereby by the twist the solid is coated by the enveloping substance.

It has been shown that the specifically heavier substance component or another substance component with a higher Surface tension forms an outer jacket for each particle. This coating phenomenon is likely to affect the angular momentum that each particle receives when it is reflected on the rotating surface.

For example, it was possible in this way to generally dust a suspension of Lactobacillus acidophilus in liquid fat

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and completely embed the rod-shaped lactic acid bacteria through the type of atomization. This sheathing in an outer fat layer, which is crystallized at the same time, the lactic acid bacteria are preserved, d. H. against the oxidative degradation · protected, as air or oxygen has no access to them.

For an even better understanding of the invention, two exemplary embodiments are described below with reference to the schematic drawing described:

i'ig. 1 shows an axial section through the first exemplary embodiment;

2 shows the atomization paraboloid seen in the axial direction;

Fig. 3 shows a further embodiment in axial section.

At the end of a shaft 1 there is a cylinder 2 with a plurality coaxial through bores 3 is provided and with its front (right) area in a coaxial to it parabolic shell 4 (hereinafter referred to as paraboloid) protrudes.

The rear area of the cylinder 2 is of a hollow cylinder 3, into which the liquid to be atomized is entered via a connection 6 by means of a pressure pump 7.

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The shaft end emerging from the cylinder cover 8 is over a continuously variable transmission 9 is connected to the drive motor 10.

The parabolic dish 4 is determined by having an irarabel around an axis 11 rotates, which is provided parallel to and at a distance from the parabolic axis 12. The axis of rotation is the Parabola 11 at the same time the axis of rotation of the cylinder 2 or the shaft 1. The parabolic shell 4- can therefore be put together think from an infinite number of narrow parabolic sectors, and thus call them "sum paraboloid".

Each bore 3 lies on a parabolic axis and opens in particular at the focal point of the associated parabola, namely by the end face 13 of the cylinder 2 on which the channels 3 open out, lies in the "focal plane" of the "sum paraboloid".

The mode of operation of the atomizing device can be clearly seen:

Driven by the motor 10, the cylinder 2 rotates together with the sum paraboloid 4 while the liquid is in via pump 7 the hollow cylinder 5 is entered. In each borehole 3, the liquid is given a certain pressure due to the given pressure axial speed; a radial velocity component is superimposed on this axial velocity component, which comes from the centrifugal force due to the fiotation.

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-TT-

Both components together result in an exit beam or Exit bundle 14 obliquely outwards. This exit bundle 14 runs from the focal point to the parabolic shell 4 and is therefore reflected on this. '■

It should be noted that the cylinder 2 and thus the bores 3 rotate and that a plurality of such bores 2 are provided.

This results in an exit cone 15 'on the inner wall of the sum paraboloid 4 is deflected according to the law of reflection into a substantially coaxial bundle 16 of Blasting the finest particles.

The already relatively fine particles in the exit cone 15 are further divided on the inner wall of the paraboloid 4. It should be noted that the peripheral speed on the The point of impact 17 is far higher than at the exit at the end face 13- Each particle is thus in the reflection Due to the higher peripheral speed, it is sheared, ground or split into a large number of finer particles.

The parabolic shell 4 is surrounded by a rigid heating shell 18, which radiates heat from the rotating parabolic shell 4 releases the intensity of which can be regulated thermostatically.

Both the pressure and the speed are preferably _stu-

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infinitely adjustable. In the example there are 16 µm axial bores provided, but a different number with a different bore diameter can also be provided ...

In the example, the inner surface of the sum paraboloid is 4 smooth, but it can be granular, ribbed, finely ribbed (in the circumferential direction and in the axial direction), with which the structure of the particles can be influenced.

The sum paraboloid can also - if the atomization area is to be expanded or narrowed - be expanded or tapered in the direction of the exit side. This can be done through extension or tapering of the parabolic shell and by analogous shifting of the focal plane in the sighting of the entry or exit side.

The embodiment of FIG. 3 is characterized by the Training of the bores 3 in the cylinder 2. And that have Bores 3 in their central area a bottleneck 20. From From this narrow point 20, the bore widens in both directions. This shape creates a too strong, performance-reducing pressure build-up counteracted. In the liquid flow, after the narrow point through the increased flow velocity creates a negative pressure, which results in the function of a suction nozzle or venturi nozzle. These Shape also favors the rolling effect.

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If the substance to be atomized contains solid particles or consists of materials with different surface tensions, this shape of the holes also makes the named Sheathing effect favored.

As Fig. 3 further shows, three are axially pluggable Parts provided, namely a stationary part or stator 21 with a continuous cylindrical bore 22 into which two further parts 23, 24 inserted from opposite sides and are plugged together axially, which together form the motor of the device.

One Eotorteil 23 has the distributed over its circumference Bores 3 and carries the paraboloid 4. On the entry side of these bores 3 is a JRing groove 24 or the like A taper is provided into which a feed channel 6 for the liquid to be atomized opens. The other part of the rotor 24 in turn, is attached to the stump 1 of the drive shaft.

For sealing between the stator 21 and the two ßotortteile 23, 24 radial labyrinth seals are provided, and that are concentric on the two end faces of the stator 24 to each other Nuttoi provided, in which appropriately shaped annular webs on the two Kotor parts 23? 24. intervene.

Claims : 309885/0359 "~" ~~

Claims (16)

Expectations 1. Device for atomizing liquid to pasty Substances on the inner wall of a shell rotating about its axis of symmetry, characterized in that the Shell has the shape of a fiotations paraboloid (4 ·), in which the axis of rotation (11) at a distance and parallel to the parabolic axis (12) and that a cylinder is coaxial and rotatable with the shell (4) about the same axis (2) with a number of eccentric, essentially axially parallel bores (3) for supplying the liquid is provided under pressure, the bores (3) on the end face (13) of the cylinder protruding into the shell (2) open out at the focal point of the respective parabola. 2, device according to claim 1, characterized in that the shell (4) sits non-rotatably on the circumference of the cylinder (2) protruding into it. 3 · Device according to claim 1, characterized in that the shell (4) and the cylinder (2) with different Speeds or opposite to each other are rotatable. 4. Device according to claims 1 to 3i characterized that the bores (3) in the cylinder (2) according to Art of a venturi tube from its rear end 309885/0359 next taper conically and then widen again conically towards the front face. 5. Device according to claims 1 to 3, characterized in that that the bores are rounded or angular in cross-section, e.g. B- rectangular, square, triangular, are. 6. Device according to claims 1 to 5 »characterized in that that the rear part of the cylinder (2) with the holes (3) ending on its rear face protrudes into a pressure-resistant hollow cylinder (5) to which a supply line (6) for the liquid is connected is. 7. Device according to claims 1 to 6, characterized in that that the shell (4) and the cylinder (2) are surrounded by a heating device (18). 8. Device according to claims 1 to 7> characterized in that the speed up to approx. 25,000 revolutions / minute and the pressure can be up to approx. 9 · Device according to one or more of the preceding Claims 1 to 8, characterized in that optionally two or more are arranged on a feed cylinder (2) Parabolic shells (4) with different widths' the parabolic dish and / or different shape or 309885/0359 Number of holes (3) are provided. 10. The device according to claim 9> characterized in that a parabolic shell is welded to a hollow cylinder, which can optionally be attached to the actual feed cylinder (2) rotatably attachable., 11. Device according to one or more of the preceding claims, characterized in that the bores (3) end at the inlet side in a common annular space (25) into which the feed line (6) opens. 12. The device according to claim 11, characterized in that a stator (21) with a diirchierenden bore (22) is provided is, in which from opposite sides two parts (23, 24) which together form a rotor are inserted are, of which one part (23) has the bores (3) and the parabolic shell (4), while the other rotor part (24) can be connected to the drive shaft. 13 · Device according to claim 12, characterized in that a concentric groove or several concentric grooves on the two annular end faces of the stator (21) are provided, in which corresponding annular webs engage on the facing sides of the Rotor parts (23, 24) are formed (labyrinth seal). 309885/0359 14. Device according to one or more of the preceding Claims, characterized in that the inner surface the atomizing bowl (4) is polished or roughened, in particular grained, ribbed, finely ribbed. 15 · Device according to one or more of the preceding Claims, characterized in that the sum of free bore cross-sections in the feed cylinder (2) is smaller than the cross section of the feed pipe into the pressure cylinder. 16. Device for atomizing liquids on the inner wall a shell rotating about its axis of symmetry, characterized in that it is coaxial at the apex of the shell a nozzle with a large number of bores aligned radially along a conical surface is stationary or channels for supplying the liquid under pressure is provided, and that the curvature of the concave body is held so that the impinging liquid particles be reflected on the wall of the concave body. 17 · Process for converting a substance mixture consisting of solid and liquid particles or only liquid particles into a powder or a gravel, the particles of which are uniformly coated by one of the material components are, characterized in that the mixture of substances by TO 9 8 8 5/0359 - 16 - a nozzle radiates onto a rotating surface of revolution is applied at such an angle and at such a speed that the impinging Particles are reflected on the rotating surface. 309885/0359