ES2252697T3 - SPRAY NOZZLE WITH ROTARY CIRCULAR OPENING. - Google Patents

Abstract

An atomisation nozzle (10) comprises a flow channel (16) which is annular in cross-section, for the supply of a medium for atomisation, enclosed by two radially-separated walls (18, 30) and which opens out in an annular nozzle opening (40). Furthermore, a second flow channel (50), enclosing the first flow channel, is provided for supply of a gaseous spraying medium (65), which also opens out in an annular nozzle opening (54). According to the invention, the walls (18, 30) enclosing the first flow channel (16) may rotate relative to each other about a nozzle longitudinal axis (70).

Description

Spray nozzle with circular opening rotary

The invention refers to a nozzle of spraying, with a first flow channel, with cross section  annularly, to use a medium to be sprayed, which is limited by two walls radially separated from each other and leading to in an annular nozzle opening, and with a second channel of flow surrounding the first to guide a gaseous medium of sprayed, which in turn leads to a nozzle opening cancel.

A spray nozzle of this class is known, for example, through patents DE-702.425 and DE-19.749.071 A1. The patent DE-702.485 shows a spray nozzle of according to the preamble of claim 1. This kind of spray nozzles serve to spread a sprayable medium, usually a liquid, but sometimes also a powder, with help of a gaseous sprinkler medium.

For this, the medium is transported under pressure. spread through the ring-shaped flow channel and / or of slit up to a nozzle opening in the form of an annular slit.

This first annular flow channel is surrounded by a second flow channel, also annularly, and this flows near the first flow channel, also in a nozzle opening annular and / or slit.

According to the mouth of the head of the nozzle, such nozzles spread axially or more or less laterally  off the axial axis with an increasing spray angle, with near spray angles of up to 180º and covering an angle 360º around the mouth of the head.

These nozzles find wide application in devices for the treatment of particulate material, by example to granulate or coat such particles. To granulate it spray with a sticky liquid that serves to glue the particles to in order to form large agglomerates, that is, granules desired

To coat a layer of surface coating.

These devices have application especially in the pharmaceutical industry, to treat materials contained in pills, which are produced as very fine powder, as well as for Granulate compressible powder and turn it into pills.

In the coatings pills are coated or granules already finished, or whole pills, with a layer of exterior revestment.

Depending on the embodiment of the device, the nozzles spray vertically upwards, but there are also fixed nozzles, which sprinkle inclined, horizontally or also in some cases that are directed vertically from top to bottom.

Through this class of spray nozzles, they spread suspensions, dispersions and solutions, using also in the so-called "Hot-Melt" methods (hot melt), in which wax or grease fusions are made It lasts under thermal influence.

To get as fine a spray as possible, it works with fluid passage sections in the flow channels annularly having the order of <0.25 mm.

In the practical use of such spray nozzles it has been proven that with suspensions or heavy dispersions, due to undissolved solid percentages, they may arise partial obstructions of the small cross sections of fluid.

This must also be taken into account especially when said solid percentages have a fibrous character or crystalline.

If we take as an example the nozzle before mentioned, with a spray angle of 180º and an angle of 360º envelope, then the nozzle head spreads a cone in the form of a flat flan. If obstructions occur, then in some peripheral areas the annular slit does not come out No means to spray. This has extremely negative effects. about the result of the treatment, which wants to be achieved with a apparatus, in which one of such nozzles is arranged sprayers

For example, in a bed covering fluidized the material to be treated swirls or moves around the nozzle, so that an irregular spray of the nozzle, due to peripheral obstructions, so that gets a treatment of irregular results.

Therefore, it is also a longing for this technology get a treatment with the most regular results possible, for example getting granules within a range of very narrow granulometry or coatings with a layer thickness as equally as possible.

Therefore, it is the subject of the present invention develop a spray nozzle of the aforementioned class, with which can also be sprayed regularly spraying media that tend to form obstructions.

According to the invention, this object is get as indicated in the attached claims.

It has been determined that, with such a form of realization of the walls that form the slit, is set to the annular slit a centrifugal and radial movement, that is a toroidal movement The medium to spread fed in the sense axial through the annular slit is also displaced in a rotational movement through the rotating walls relatively close to each other, becoming the aforementioned toroidal movement If media is now passed through a such a flow channel, which tend to produce obstructions or even small solid lumps, then thanks to the rotational conformation a certain crushing of such fluid is achieved from the slit of fluid solid lumps, which if fixed walls could cause a fluid slit blockage. Thanks to the embodiment rotary almost a kind of self-cleaning effect is achieved, of so that the medium to be sprayed ends up leaving the opening of the annular nozzle, distributed peripherally regular.

In another embodiment of the invention, both walls can also move axially one relative to the another, so that the width of the slit of the nozzle opening of the first annular flow channel.

This solution now has the remarkable advantage of which is possible, thanks to axial mobility, to vary the width of nozzle opening slit of this first flow channel and especially also closed power. When the nozzle is out of service or while not in use, the opening of the nozzle, so that dirt cannot penetrate or occur obstructions caused by drying or the like in the opening of nozzle.

A remarkable essential advantage of this ability to axial displacement is that regulation is achieved automatic width of the annular slit within a certain bandwidth

The usual annular slit in such nozzles sprayers have a width of 0.1 to 0.25 mm, and is desirable be able to spread 1 to 5 grams of the medium to be sprayed per millimeter of slit length

Axial mobility allows, depending on the nature of the medium to be spread, which automatically adjusts the height of the slit. If you pass a certain medium with a predetermined pressure through the first flow channel, possessing intrinsic properties, for example its viscosity in case of a liquid, or its fluidity and toughness in case of emulsions, they have a remarkable influence on the amount that can go out for longitudinal millimeter through a groove. Said with others words, there are liquids that pass relatively easily to through one such slit, while others need a slit something wider so that the same amount comes out.

In practical applications it has become manifest that naturally within a certain area By default, the width of the slit adjusts itself to an optimal value for certain boundary conditions, so The nozzle is almost self-regulating.

The aforementioned possibility of closing the mouth from the nozzle of the first flow channel in the stopped state can easily achieved, for example in a stopped nozzle, since at least one of the movable walls performs the movement of closing when falling due to the force of gravity.

In the case of angled nozzles, horizontal or fully hanging, this movement can be achieved by a spring force or other mechanisms.

In another embodiment of the invention there are power elements, at least on one of the walls rotating with respect to each other, which control the movement of the spray medium transported to the nozzle opening.

The provision of said feeding elements It has the remarkable advantage that the shaped toroidal movement by the sense of axial transport and the rotating walls is encouraged by the feeding elements, directing it and also feeding him

Additionally, these feeding elements they can also serve as mechanical means to transport and in If necessary, properly crush possible lumps of solids dragged.

In an embodiment of the invention one of the walls are fixed and the other wall is shaped so swivel

From the constructive point of view, this measure It has the advantage that only one of the walls should move, and therefore, only actuators are required for one of those walls.

In another embodiment of the invention one of The walls are fixed and the other can move axially.

Also in this case, the advantage of the simple construction of the embodiment of the additional capacity of axial displacement of the walls a Regarding another.

In another embodiment that wall, which It is rotatable, it can also move axially at the same time.

From the constructive point of view, this solution has the advantage that the possibility is available both of disposition as of rotation, as well as of the possibility of displacement, depending only on a single wall.

In another embodiment of the invention the axial movement government is obtained through feeding  of the medium itself to be sprayed.

This solution allows the aforementioned effect of automatic adjustment of the slit width of the opening of nozzle of the first flow channel.

In another embodiment of the invention, the axial displacement capability is designed such that, in a stopped state, the nozzle opening of the first channel is closed flow.

This solution allows, in a constructive way extremely easy, the aforementioned closure of the opening of nozzle of the first flow channel, which then occurs exactly when no means to spray through the First flow channel.

In another embodiment of the invention, the axial closure occurs against a return force, which moves the movable wall (walls) in the closed position of the nozzle opening.

As already mentioned, it can be used as force of return the force of gravity, so that with the nozzles stopped the moving wall can move to the closed position thanks to the relative displacement towards the other due to the force serious.

If the force of gravity is not enough or not be able to carry out said movement, the same it can be done through other elements of government, such as by example springs or other elements.

In another embodiment of the invention the axial displacement capacity of the walls is made up of such that, in a state of unemployment, the opening of nozzle of the second flow channel.

This solution has the advantage that in state when both nozzle openings are closed.

This solution not only has the advantage before mentioned that no dirt can enter the nozzle, but that it also has the advantage that the waste that in certain cases are still in the flow channels, so that in the case of transport or disassembly, such remains may Go out and get dirty.

In another embodiment of the invention, the revolving wall carries a fan on the outer side of a spray nozzle head, so that the head is released from possible adhesions in the area of the opening of the nozzle.

A problem, which always arises again, is the fouling of the mouth of the head generally due to the uncontrolled movement of secondary air, which occurs in the area around the liquid or spray slit, respectively. Due to the high speed of blowing a subpressure zone is formed, which is circling around, which attracts even droplets of sprayed liquid and deposits it on the mouth of the head. Therefore an accumulation or more and more the formation of a dry solid of the sprayed liquid occurs.
do.

The presence of the fan now allows keep this critical area free of such adhesions. So, the rotation according to the invention of the wall not only contributes to obtain optimum conditions inside the nozzle, but that said rotary movement can at the same time avoid the adhesions on the outer side of the head.

In an advantageous embodiment of the invention, one of the walls is shaped as an outer side of a central axis, which is rotatable.

This measure has the constructive advantage that by means of a simple constructive system, that is to say the central axis, the rotating wall is achieved.

In another embodiment of the invention, the feeding elements are shaped as sections of impeller

This solution has the advantage that this is the case. especially regular feeding of the movement of the medium to spray.

If the impeller sections are formed in the outer side of the aforementioned central axis, on the one hand it turns out extremely simple to build and you can get a food especially favorable and aimed at the objective pursued. The length and number of impeller sections, as well as the number of transport wheels, whose section shapes may also vary, so that means to be sprayed can also be treated problematic

In another embodiment of the invention, the axis It is driven by an air driven motor compressed.

This solution has the advantage, from the point of constructive view, that with such a spray nozzle is available without more than one gaseous medium to spread the medium to be sprayed, when be connected to a sprinkler air source, usually compressed air. In this way part of that air can also be used to drive the motor that deals with the movement Rotating between the walls.

In another advantageous embodiment, the shaft goes inserted over a drive pin, which allows a certain axial shaft movement.

This solution has, from the point of view constructive, the special advantage that with this measure the axis it can both rotate and move axially in a certain way measure.

The measure of mobility can be limited, by example, through a lateral connecting spike that runs in a Longitudinal hole in the drive pin.

In another advantageous embodiment of the Invention the fan shaft is located on the head.

This solution has the advantage that with this advantageous embodiment at the same time is obtained on the shaft middle central.

It is understood that the characteristics mentioned above and those that will still be mentioned below can not only be used in the combinations mentioned but also in others combinations or individually, without leaving the scope of the invention.

The following is described and explained with more detail the invention with the help of some examples of ways of chosen realization, together with the attached drawings. In the same:

Figure 1 shows, partially in section longitudinal, a side view of a first example of the shape of realization of a spray nozzle according to the invention;

Figure 1a is an enlarged view of the area of Figure 1, marked with a circle, at the top right;

Figure 2 is a side view of the nozzle sprayer, rotated 90º with respect to that represented in the Figure 1;

Figure 3 is a corresponding representation to the section in figure 1 but another example of how to realization of a spray nozzle, with fan arranged in the head; Y

Figure 4 is a front plan view of the spray nozzle head of figure 3.

A spray nozzle represented in the Figures 1 and 2 are indicated as a whole with the number of reference 10.

The spray nozzle 10 has a body of nozzle 12 approximately bar-shaped, in which it goes flanged, in the representation of figures 1 and 2, one end bottom of an engine 14.

In the nozzle body 12 there is formed a first flow channel in the form of a ring and / or slit.

This first flow channel 16 is limited by its inner side by means of an inner wall 18, whose side outer 20 is a central axis 22.

The shaft 22 is inserted on a spike of polygonal drive 24 protruding from motor 14, at whose object carries a corresponding slit 26 at its end lower.

On the one hand, in this way a secure connection to the rotation between motor 14 and shaft 22, that is, when the engine is running 14 axis 22 rotates around central longitudinal axis 70, and at same time represents the middle longitudinal axis of the nozzle of spray 10.

The insertable union is made in such a way that also provides a certain axial mobility of the axis 22, whose object and motive will be described later with respect to its functioning.

Axial mobility and the limitation of the value of axial movement can be achieved by the fact that in the spike A vertical longitudinal hole is formed, which houses a transverse bolt, which is inserted into a radial hole of shaft 22 in the groove area 26.

The first flow channel 16 is limited externally by an external wall 30, formed by a side inside of a hole or central through hole 34 in the body of the nozzle 12. Both the axis 22 and the body of the nozzle 12 widens in the form of a trumpet in opposition to the engine 14, forming a flare 36 and a flare 38, as can see especially in figure 1a.

This forms a nozzle opening 40 oriented approximately horizontal, in the form of an annular slit 42 that circle 360º.

The width of the annular slit 42 can be varied. by axial movement of axis 22, the variation of order from 0.1 to 0.25 mm

As can be seen especially in the figure 2, the first flow channel 16 is connected to a side connection 44, so that through said connection 44 a power can be fed means to be sprayed in the first flow channel 16, for example a liquid 45, being transported by the first flow channel 16 and leaving through the annular slit 42. The transport and feeding of this liquid 45 are also promoted by feeding elements 48 in the form of two impeller sections 46 and 46 'on the side exterior 22 of axis 22, the height of an impeller being such that the it corresponds approximately to the slit width of the first flow channel 16 inside the spray nozzle 10.

In the exemplary embodiment represented, the profile of the impeller 46 is such that it is approximately flat on the inner side 32 of the central opening 34, other profiles being naturally possible, such as rounded or pointed impeller profiles.

To be able to finely spray the liquid projection or the means of spraying, which can also be a powder, through the annular slit 42 a second channel of flow 50.

This second flow channel 50 surrounds the first inner flow channel 16 and leads to a widening of the same direction 52 in a nozzle opening 54, which also has the shape of an annular slit 56. The annular slit 56 is arranged in such a way that it is directly next to the slit annular 42, in the exemplary embodiment shown of the nozzle vertical spray 10 is directly below the first annular slit 42. The second flow channel 50 is limited internally by the nozzle body 12, and externally by a swivel bushing 58. Bushing 58 is screwed to the body of the nozzle 12 by means of a thread 60.

As can be seen especially in the figure 2, the bushing 58 carries a scale 62 on its outer side.

Turning bushing 58 can change consequently the slit width of the annular slit 54.

The second flow channel 52 is communicated with the outside world through a connection 64 that stands out radially, so that a gaseous medium can be introduced, into spray air form 65, inside the nozzle body 12.

The engine is shaped as a driven motor pneumatically, ie compressed air 67 is introduced through of an inlet 66 and said compressed air 67 comes out again through of an exit 68.

During operation, the engine 14 is controlled and operated by compressed air, as it has been indicated above, so that the shaft 22 rotates. The number of revolutions are adjusted, depending on the respective case of application, to the medium to be sprayed and can be of the order of 1 to 1000 revolutions per minute. A connection is fed through connection 44 medium to be sprayed, for example a sticky liquid to be sprayed to granulate, and is expelled through the annular slit 42. The liquid it can also consist of a substance melted in the Exterior.

Said externally driven liquid spreads to mode of a fine mist by means of the spray air 65 that comes out of the second flow channel 50 and respectively by its opening of nozzle 54, the spray air normally being at a pressure from 0.5 to 5.0 bar.

Therefore a corresponding flan or cone is formed of horizontally directed spray, as indicated in the Figure 2 by reference number 75.

As mentioned before, the width of slit of the annular slit 56, through which the air from sprinkling, can be varied by rotating bushing 58.

The slit width of the annular slit 42, by which the liquid to be sprayed out 45, is regulated automatically thanks to the axial mobility of the axis 22, by a side by the pressure of the liquid provided by the liquid to spray and also, to some extent, for the properties intrinsic of the liquid, as well as its viscosity or its nature as emulsion, tarquinamiento or dusty mixture.

If the spray nozzle 10, as it has been represented in figure 1, it is shaped as a vertical nozzle and no means to be sprayed are fed, shaft 22 falls down due to the effect of gravity, thus closing automatically the annular slit 42 or the first flow channel 46, respectively,  as indicated by the double arrow in figure 1a.

It can be seen in figure 1 that axis 22 It has its outer side closed by a head 80, approximately  mushroom.

In a practical application it has become manifest, as indicated in figure 2, that in an area 88 of the outer edge of the head 80 there are certain areas problematic, in which they are deposited again and again sprayed particles or even solid particles in an apparatus of swirling cape that goes around. This area has been indicated with reference number 88 in figure 2.

In Figures 3 and 4 a variant of embodiment which, as regards the conformation of the spray nozzle is as described with reference to the exemplary embodiment of figures 1 and 2.

Additionally there is a fan 82 mounted on the outer side of the head 80.

Said fan 82 carries several centrifugal wings fan curves back 84 that suck air from a axial tube 86 and, as can be seen especially in the view in plant of figure 4, indicated by arrow 89, blow said air radially Therefore, the critical zone, indicated by the number of reference 88 in figure 2, is blown freely, so that there are no adhesions or accumulations of solid particles or Undesirable liquid.

This air blown additionally by the fan 82 can be driven to the upper surface of the cone spray 75 shown in figure 2, or it can be governed to make it swirl additionally or allocate it to others objectives.

According to, before the sucked air proceeds through axial tube 86, this can be used as "microclimate", for example as a hot air, in order to keep the drops of molten as long as possible liquid fed as fusion, so those particles that they must be sprayed through the spray nozzle, they can be coated with still liquid particles at a certain distance from  the nozzle

In the exemplary embodiment before described one of the walls, that is the outer wall 30, which it forms the first flow channel 16, the inner wall 18, namely the internal side 20 of shaft 22 was rotating.

It is also foreseeable to perform it cinematically upside down, that is, in certain cases, make both walls have rotating movement.

Claims (16)

1. Spray nozzle with a first flow channel (16), whose cross section has an annular shape, to use a means to be sprayed (45), which is limited by two walls radially separated from each other (18, 30) and which flows in an annular nozzle opening (40), and with a second flow channel (50) that surrounds the first (16) to guide a gaseous spray medium (65), which in turn flows into a nozzle opening annularly (54), characterized in that the walls (18, 30) that surround the first flow channel (16) can rotate relative to each other around a longitudinal axis of nozzle (70). 2. Spray nozzle according to claim 1, characterized in that both walls (18, 30) can also move axially relative to each other, so that the slit width of the nozzle opening (40) varies . 3. Spray nozzle according to claim 1 or 2, characterized in that at least one of the rotating walls with respect to each other (30) there are feeding elements (48) that control a movement of the medium to be sprayed (45) to be transported to the nozzle opening (40). 4. Spray nozzle according to one of claims 1 to 3, characterized in that one of the walls (30) is fixed and the other wall (18) is rotatably shaped. 5. Spray nozzle according to one of claims 2 to 4, characterized in that one of the walls (30) is fixed and the other (18) can move axially. 6. A spray nozzle according to one of claims 2 to 5, characterized in that that wall (30), which is rotatable, can also move axially at the same time. 7. Spray nozzle according to one of claims 2 to 4, characterized in that the steering of the axial movement is obtained through the feeding of the medium itself to be sprayed (45). 8. A spray nozzle according to one of claims 2 to 7, characterized in that the axial displacement capacity is designed such that, in a stopped state, the nozzle opening (40) of the first channel is closed. flow (16). 9. Spray nozzle according to one of claims 2 to 8, characterized in that the axial closure is produced against a return force, which moves the movable wall (walls) in the closed position of the opening of the nozzle. 10. A spray nozzle according to one of claims 2 to 9, characterized in that the axial displacement capacity of the walls is shaped such that, in a stopped state, the nozzle opening is also closed (54 ) of the second flow channel (50). 11. Spray nozzle according to one of claims 1 to 10, characterized in that the rotating wall has a fan (82) on the outer side of a head (80) of the spray nozzle (10), so that the head (80) is released from possible adhesions in the area of the nozzle openings (40, 54). 12. A spray nozzle according to one of claims 1 to 11, characterized in that one of the walls (18) is formed as an outer side (20) of a central axis (22), which is rotatable. 13. Spray nozzle according to one of claims 3 to 12, characterized in that the feeding elements (48) are formed as impeller sections (46, 46 '). 14. Spray nozzle according to claim 12 or 13, characterized in that the shaft (22) is driven by means of a motor (14) driven by compressed air. 15. Spray nozzle according to claim 14, characterized in that the shaft (22) is inserted on a drive pin (24) of the motor (14), which allows a certain axial movement of the shaft (22). 16. Spray nozzle according to one of claims 11 to 15, characterized in that the shaft (22) of the fan (82) is located on the head (80).