PNEUMATIC ATOMIZING NOZZLE

Abstract

A pneumatic atomizing nozzle (10) which in a preferred form can be supplied with gas by means of a fan (43). The pneumatic atomizing nozzle (10) has a nozzle body (11), which bounds a flow space (21). The pneumatic atomizing nozzle (10) also has a liquid channel (27) having an outlet opening (38). Within the flow space (21), a liquid film (41) is formed, which is transported within the flow space (21) to a nozzle outlet (17) by the gas flow. The outlet opening (38) of the liquid channel (27) defines an outlet direction (A) for the liquid into the flow space (21), which in the preferred embodiment is opposite the flow direction (S) of the liquid film (41). At least in some sections, the liquid channel (27) and the outlet opening (38) extend transversely through the nozzle body (11) in a curved, wound, or meandering manner.

Claims

1-20. (canceled)

21. A pneumatic atomizing nozzle (10) comprising a nozzle body (11) that defines a flow space (21); a gas channel (14) for supplying a gas, said gas channel (14) terminating in the flow space (21); a liquid channel (27) for supplying a liquid, said liquid channel (27) having at least one outlet opening (38) through which the liquid is discharged into the flow space (21) in order to be charged with gas from the gas channel (14) and form a liquid film (41) in a flow direction (S) in the flow space (21); and said at least one outlet opening (38) defining an outlet direction (A) out of the liquid channel (27) for the liquid, said outlet direction (A) being opposite to the flow direction (S) of the liquid film (41) in the flow space (21).

22. A pneumatic atomizing nozzle (10) comprising a nozzle body (11) that defines a flow space (21); a gas channel (14) for supplying a gas, said gas channel (14) terminating in the flow space (21); a liquid channel (27) for supplying a liquid, said liquid channel (27) having at least one outlet opening (38) through which the liquid is discharged into the flow space (21) in an outlet direction (A) in order to be charged with gas from said gas channel (14) and form a liquid film (41) in the flow space (21); and said liquid channel (27) and the at least one outlet opening (38) of the liquid channel (27) extend in a manner such that when they project onto a plane that extends transversely through the flow space (21) and perpendicularly to the outlet direction (A), a line is formed that is curved, wound or meandering, at least in some sections.

23. The pneumatic atomizing nozzle (10) of claim 21 in which the liquid channel (27) is arranged inside at least a section of the flow space (21).

24. The pneumatic atomizing nozzle (10) of claim 21 in which the liquid channel (27) is formed through a guide body (36) that is configured so as to guide liquid flowing to a nozzle outlet (16).

25. The pneumatic atomizing nozzle (10) of claim 24 in which the guide body (32, 33) is arranged to divide a liquid flow in the flow space (21).

26. The pneumatic atomizing nozzle (10) of claim 24 in which the guide body (36) has the form, in at least some section, of an airfoil shape in cross-section.

27. The pneumatic atomizing nozzle (10) of claim 21 in which the liquid channel (27) extends in an arcuate manner around the flow direction (S) of the liquid film.

28. The pneumatic atomizing nozzle (10) of claim 27 in which the liquid channel (27) has the form of a spiral.

29. The pneumatic atomizing nozzle (10) of claim 28 in which the spiral form of the liquid channel (27) extends at least over one revolution.

30. The pneumatic atomizing nozzle (10) of claim 21 in which the outlet opening (38) is an outlet slit or gap (38).

31. The pneumatic atomizing nozzle (10) of claim 30 in which the outlet slit or gap (38) is arcuate in at least some sections.

32. The pneumatic atomizing nozzle (10) of claim 21 in which the gas channel (14) terminates in the flow space (21) opposite the outlet opening (38).

33. The pneumatic atomizing nozzle (10) of claim 21 in which the flow space (21) tapers in the direction of a nozzle outlet (17) of the nozzle body (11).

34. The pneumatic atomizing nozzle (10) of claim 21 in which the nozzle body (11) has a nozzle outlet (17) that is curved around the flow direction (S).

35. The pneumatic atomizing nozzle (10) of claim 21 in which the nozzle body (11) has a cylindrical form and comprises a gas connection that is fluidically connected to the gas channel (14) and a liquid connection that is fluidically connected to the liquid channel (27), said gas connection and liquid connections being arranged together on a common face side (12) of the nozzle body (11), and the nozzle body (11) has a nozzle outlet arranged on an opposite face side (13) of the nozzle body (11).

36. The pneumatic atomizing nozzle (10) of claim 21 in which the nozzle body (11) is made in one piece with the gas channel (14) and the liquid channel (27) formed by 3D printing.

37. The pneumatic atomizing nozzle (10) of claim 21 including a fan (43) which is arranged for supplying the pneumatic atomizing nozzle (10) with gas.

38. A method (50) for operating a pneumatic atomizing nozzle comprising the steps: supplying (51) liquid to a liquid channel (27); ejecting (52) the liquid from the liquid channel (27) into a flow space (21) in a liquid outlet direction (A); supplying (53) gas to a flow space (21) for which a gas flow direction (S) has been defined, said gas flow direction being different from the liquid outlet direction (A); charging (54) the liquid entering the flow space (21) with the gas in such a manner that the liquid is deflected and a liquid film (41) is formed, said liquid film flowing in a flow direction (S) opposite the liquid outlet direction (A) to a nozzle outlet (17); and dispensing (55) the liquid through the nozzle outlet (17).

39. The method (50) of claim 38, wherein supplying the gas to the flow space (21) is done using a fan (43).

40. The method (50) of claim 38 including ejecting the liquid out of the liquid channel (27) into the flow space (21) linearly through an outlet gap (38) that is curved in a spiraliform manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG. 1 is a schematic perspective of a pneumatic atomizing nozzle in accordance with the invention;

[0049] FIG. 2 is an enlarged perspective of a longitudinal section of the pneumatic atomizing nozzle depicted in FIG. 1;

[0050] FIG. 3 is a further perspective of the illustrated pneumatic atomizing nozzle;

[0051] FIG. 3a is a longitudinal section of the pneumatic atomizing nozzle shown in FIG. 3;

[0052] FIG. 4 is a fragmentary, more detailed perspective of one of the liquid and gas directing passages of the illustrated pneumatic atomizing nozzle;

[0053] FIG. 5 is a schematic representation of a pneumatic atomizing nozzle which includes anatomizing air fan and liquid supply;

[0054] FIG. 6 is a diagrammatic depiction of a method of operating a pneumatic atomizing nozzle according to the invention; and

[0055] FIGS. 7a-7f are plan views of exemplary configurations of the liquid channel and outlet openings of pneumatic atomizing nozzles in accordance with various embodiments of the invention.

[0056] While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] Referring now more particularly to FIG. 1, there is shown an illustrative pneumatic atomizing nozzle 10 in accordance with the invention that comprises a nozzle body 11 that is essentially cylindrical. The nozzle body 11 has a first face side 12 and, preferably, a planar second face side 13. A gas connection 14 and a liquid connection 16 are arranged on the first face side 12 (see FIG. 5). A nozzle opening or a nozzle outlet 17 is arranged on the second face side 13 of the nozzle body 11. The nozzle outlet 17 is an outlet slit or an outlet gap that is wound around the cylinder axis Z by more than two complete revolutions to form a planar spiral.

[0058] FIG. 2 shows a longitudinal section through the nozzle body 11. Inside the nozzle body 11, a gas channel 18 adjoins the face side 12. The gas channel 18 is essentially cylindrical and is delimited by the cylindrical wall 19 of the nozzle body 11. The nozzle body 11 comprises a flow space 21 that is also delimited by the cylindrical wall 19 of the nozzle body 11. Inside the nozzle body 11, the gas channel 18 terminates axially in the flow space 21. A spiral wall 22 is arranged in the flow space 21. Due to the spiral wall 22, the flow space 21 is in the form of a spiral arm. The center axis Z of the spiral is parallel to or coincident with the cylinder axis Z.

[0059] With a planar, axially open inlet side 23, the flow space 21 adjoins the gas channel 18. The inlet side 23 of the flow space 21 forms an open face side that faces the face side 12 at which the gas channel 18 is connected to the gas connection 14. The flow space 21 is radially divided by the spiral wall 22, but is open in circumferential direction U, continuous and unbranched. The flow space 21 formed by a single spiral arm in FIG. 2 may also be formed by at least two spiral arms. Alternatively, the flow space 21 may, for example, have several spaces in the form of concentric cylindrical rings, said spaces comprising radial flow connections and dividing the gas flow in radial direction and in circumferential direction U.

[0060] The flow space 21 has a front section 24 and a rear section 26. The front section 24 borders the inlet side 23 and has a radial spiral arm height H that is constant along the cylinder axis Z. The rear section 26 adjoins the front section 24. In the rear section 26, the spiral arm height H decreases gradually in the direction toward the nozzle outlet 16. As a result of this, the flow space 21 tapers overall in radial direction. The spiraliform nozzle outlet slit 17 adjoins the rear section 26.

[0061] A liquid channel 27 is arranged in the flow space 21. The liquid channel 27 comprises a supply section 28 that is arranged on the wall 19 of the nozzle body 11. The supply section 28 extends parallel to the cylinder axis Z, beginning at the first face side 12 of the nozzle body 11. The supply section 28 has a supply channel wall 29. On the one hand, the spiral wall 22 branches off transversely with respect to the cylinder axis Z in circumferential direction U, and, on the other hand, an outlet section 31 of the liquid channel 27 branches off at a radial distance with respect to said spiral wall. Preferably, the outlet section 31 has only two mounting points, wherein a first mounting point 31a is located on the supply section 28 and a second mounting point 31b is located in the center of the nozzle body 11 and connected to the inner end of the spiral wall 22. Additional mounting points, in particular bars between the spiral wall 22 and outlet channel 31 may be omitted, so that an unimpaired flow of gas and liquid is made possible axially outside along the outlet section 31. The outlet section 31 extends axially from the front section 24 into the rear section 26.

[0062] The outlet section 31 extends through the flow space 21 along the periphery of the nozzle body 11, so that a section of the liquid channel 27 is enclosed by the flow space 21. The outlet section 31 has a first channel wall 32 and a second channel wall 33. The first channel wall 32 has a first wall outside surface 34, and the second channel wall 33 has a second wall outside surface 35, each—viewed along the cylinder axis Z—being spiraliform, so that the outlet section 31 has the form of a planar spiral.

[0063] The outlet section 31 has an outlet side 37. The first channel wall 32 and the second channel wall 33 are not connected on the outlet side 37, so that—radially between the first channel wall 32 and the second channel wall 33—a gap-shaped, continuous outlet opening 38 is formed, said opening following the course of the outlet section 31. The outlet opening 38 is arranged at a distance from the inlet side 23 of the flow space 21 and faces said inlet side. The outlet opening 38 is planar and oriented transversely with respect to the gas flow direction S. Here, the outlet opening 38 has in particular the form of a planar spiral that, however, may also be configured as a three-dimensional spiral, i.e., a screw. Due to the spiral form, the outlet opening 38 extends along the periphery of the flow space 17. In particular, the outlet opening 38 extends in an arcuate manner along the spiral wall 22 and the wall 19 of the nozzle body 11. Furthermore, due to the spiral form, the outlet opening 37 extends in an arcuate manner along the periphery of the flow space 21 on a path with continuously decreasing diameter.

[0064] The side of the outlet section 31 opposite the outlet side 37 forms a stripping side 39. The outlet section 31 tapers axially in the form of a wedge toward the stripping side 39 and the nozzle opening 17, respectively, and is arranged in the rear section 26 of the flow space 17 that tapers in the direction toward the nozzle opening 17 in the form of a wedge. The first wall outside surface 34 and the second wall outside surface 35 extend from the outlet side 37 to the stripping side 39. The first wall outside surface 34 is oriented radially outward, and the second wall outside surface 35 is oriented radially inward. The first channel wall 32 and the second channel wall 33 are connected to each other on the stripping side 39 and form a tearing edge 40 for a liquid film 41 there, said liquid film flowing along the channel walls 32, 33. The stripping side 39 or tearing edge is arranged at a distance near the nozzle outlet 17.

[0065] Viewed in longitudinal section, as depicted in FIG. 2, the channel walls 32, 33 together thus form an essentially symmetrical wedge configuration or elongated drop configuration similar to an airfoil profile, relative to the longitudinal plane and plane of symmetry parallel to the cylinder axis Z.

[0066] FIG. 3 is a longitudinal section through the pneumatic atomizing nozzle 10 as described hereinabove. Due to its orientation in the flow space 21, the outlet opening 38—together with the first channel wall 32 and the second channel wall 33—defines an outlet direction A for the liquid on the inlet side 23. This is oriented in opposite direction of the flow direction S of the gas that flows from the first face side 12 to the second face side 13.

[0067] The pneumatic atomizing nozzle 10 described so far and comprising the nozzle body 11, the gas channel 18 and the liquid channel 27 is preferably configured as a one-piece integral body and can thus be produced, for example, by an additive manufacturing process, in particular, by 3D printing. Preferably, the nozzle body 11 is free of seams and joints and consists of a uniform material, preferably plastic or metal. Indeed, it is also possible to produce the nozzle body 11 with several separately manufactured and joined parts; however this is less desirable in this case—among other things due to the greater expense and the disadvantages related to seams and joints.

[0068] The pneumatic atomizing nozzle 10 described hereinabove can be used in many applications such as, e.g., for moistening or cooling objects in industrial production, for atomizing water and the like. In particular, it is suitable for use in dust precipitation systems or gas cooling systems. The pneumatic atomizing nozzle 10 is operated as described hereinafter, in which case the description relates to FIGS. 1-5:

[0069] The pneumatic atomizing nozzle 10 is charged with gas, for example air, that is moved in the direction of flow by a fan. As illustrated by FIG. 5 showing an embodiment of an inventive nozzle device 42 in a simplified block diagram; it comprises a pneumatic atomizing nozzle 10 and a fan 43, and, to do so, the fan 43 is connected to the gas connection 14 that terminates on the face side 12 in the gas channel 18 of the pneumatic atomizing nozzle 10. Due to the relative arrangement of the gas connection 14 on the face side 12, the gas channel 18, as well as the flow space 21 and the nozzle outlet 16 on the opposite face side 13, a gas flow direction S is defined in the flow space 21.

[0070] A pump 44 is connected to the liquid connection 16 on the first face side 12 of the nozzle body 11, in which case the liquid connection 16 is connected to the supply section 28 of the liquid channel 27. The pump 44 conveys water out of a liquid supply 46, so that the pneumatic atomizing nozzle 10 is supplied with liquid, for example water. The inner flow dimensions inside the nozzle body 11, in particular the spiral arm height H, the cross-sectional area of the liquid channel, the width of the outlet gap 38 as defined by the radial distance of the channel walls 32, 33 from each other, or the height of the nozzle outlet 17, etc., are adequately dimensioned, preferably are at least 2 mm, so that water loaded with contaminants can also be used for supplying the pneumatic atomizing nozzle 10, without there being a noticeable risk of plugging the pneumatic atomizing nozzle 10.

[0071] Initially, the liquid flows along the supply section 28 into the outlet section 31. Within the outlet section 31, the liquid flows along the circumferential direction U, transversely with respect to the cylinder axis Z around the gas flow S. The outlet section 31 thus defines a channel direction K in which the liquid flows in the outlet section 31 and which is oriented transversely with respect to the gas flow direction S. This is indicated in FIG. 3 by the symbols “.Math.” and “x” that symbolize a flow out of the plane of projection or into the plane of projection.

[0072] On the outlet side 37 of the outlet section 31, the liquid is linearly ejected through the gap-shaped outlet opening 38 in front section 24 of the flow space 17 in outlet direction A. Due to the arrangement of the outlet opening 38 relative to the first face side 12 where the gas channel 18 terminates in the flow space 21, the outlet direction A of the gas flow direction S is in the opposite direction.

[0073] As is shown in detail in FIG. 4, the liquid flowing out of the outlet opening 38 is caught by the oppositely directed gas flow S and deflected by 180° into the gas flow directions. Due to the gas flow, the liquid is bilaterally distributed around the outlet section 31 to the first wall outside surface 34 and the second wall outside surface 35 of the channel walls 32, 33 while forming a liquid film 41. The wall outside surfaces 34, 35 form the guide surfaces for the liquid film 41. To this extent, the channel walls 32, 33 form a guide body 36 for the liquid, said guide body extending along the periphery of the nozzle body 11. The guide body 36 divides the flow space 21 and the liquid flow outside the liquid channel 27 in radial direction, so that the liquid flows bilaterally around over the upper, first wall outside surface 34 and the lower, second wall outside surface 35 in the Figures. Due to the opposing gas flow that is largely uniform in radial direction and the essentially symmetrical guide body 36, the liquid flow is divided largely uniformly outside the liquid channel 27. The gas flowing on the liquid surface to the nozzle outlet 17 then drives the liquid film 41 in the gas flow direction S toward the nozzle outlet 17. In doing so, the liquid film 41 is also charged with the gas in such a manner that the liquid film 41 is additionally caused to oscillate. In doing so, a preliminary atomization of the liquid film 41 may already occur, while these—together with the partial gas streams—flow over the wall outside surfaces 34, 35 on the guide body 36 to the stripping side 39.

[0074] Inasmuch as the width of the flow space 21—measured between the wall outside surfaces 34, 35 of the guide body 36 and the oppositely located inside surfaces of the spiral wall 22—increasingly decrease toward the stripping side, the partial liquid flows 41 flowing over the wall outside surfaces 34, 35 become increasingly thinner and are accelerated. On the stripping side, the partial liquid flows 41 meet at the tearing edge 40 and are separated from the guide body 36 by the latter. The liquid flows are ejected together with the gas flow toward the outside through the nozzle outlet opening 17 out of the pneumatic atomizing nozzle 10, in which case the liquid is atomized—as it is being discharged—into fine liquid droplets outside the pneumatic atomizing nozzle 10.

[0075] Now reference is made to FIG. 6 that shows a flowchart illustrating a general method 50 for operating a pneumatic atomizing nozzle according to the invention that can be used, in particular, with the pneumatic atomizing nozzle 10 according to FIGS. 1-5.

[0076] The method 50 begins with the supply of liquid to a pneumatic atomizing nozzle, e.g., the pneumatic atomizing nozzle 10, through a liquid channel (e.g., 27), as illustrated by step 51.

[0077] Then the liquid flows through the liquid channels and is ejected therefrom into a flow space (e.g., 17) in a liquid outlet direction A, as illustrated by step 52.

[0078] At the same time, gas is introduced into the flow space in a gas flow direction S (step 53). The gas flow direction S is different from the liquid outlet direction A and is preferably opposite thereto.

[0079] The liquid entering the flow space is charged with the gas flow in such a manner that the liquid is deflected and a liquid film (e.g., 41) is formed, said liquid film flowing in a flow direction S to a nozzle outlet (e.g., 17) counter the liquid outlet direction A (step 54). Due to the gas flow, it is possible to pre-atomize the liquid film already up to a certain degree.

[0080] Finally, the liquid is dispensed through the pneumatic atomizing nozzle outward through the nozzle outlet. In doing so, the liquid is torn apart and finely atomized due to the flowing gas. The discharge may be accomplished in that the ejected liquid slightly spreads toward the outside in the form of a truncated cone, which further supports atomization.

[0081] In a preferred embodiment of the method 50 according to the invention, the supply of the gas into flow space occurs with a fan (e.g., 43). The use of expensive compressors is not necessary.

[0082] In another advantageous embodiment of the method 50, the ejection of the liquid out of the liquid channel into the flow space in a linear manner through a narrow outlet gap occurs preferably through a tightly wound spiraliform outlet gap. The outlet gap may—at least in some sections—also be curved, wound or serpentine. In any event, the longest possible outlet gap is formed as a result of this, and the liquid being discharged through the outlet gap can be effectively charged and be deflected as desired and/or re-shaped to form a thin liquid film, as a result of which atomization is advantageously further supported.

[0083] Numerous modifications are possible within the framework of the invention. For example, FIGS. 7a-7f show exemplary courses of liquid channels 27 with associate outlet openings 38 according to different embodiments of the invention. Shown are planar views that result by projecting the liquid channels 27 and the outlet openings 38 on a plane of projection that extends transversely through the flow space 21 and essentially perpendicularly to the outlet direction A (see FIG. 2) of the liquid out of the outlet opening 38. Although the limited width of the gap-shaped outlet openings 38 results in band-shaped curve courses when projected onto the plane of projection, these are shown here by thin lines for simple and clear illustration.

[0084] FIG. 7a shows the line of projection of the spiraliform liquid channel 27 with the outlet opening 38 of the preferred embodiment shown by FIGS. 1 to 3. The spiral form can result from a planar spiraliform or helical course of the liquid channel 27.

[0085] Instead of the spiral form the course of the liquid channel 27 with the outlet opening 38 could also take the form of a circle or of several concentric circles that are preferably continuously connected to each other, however need not be. Depending on the application, a curved arcuate section, e.g., of a circle or a spiral, that preferably subtends an angle of at least 90°, more preferably 180°, may be adequate. Particularly advantageous is an extension over at least one revolution (by at least 360°) or even over two revolutions.

[0086] FIG. 7b shows a serpentine or wound, meandering form of the course of a liquid channel 27 with the outlet opening 38 that has several—in this instance four—loops 61 that are turned by an angle of 90°, here around a central center axis of the flow space and connected to each other.

[0087] The meandering embodiment according to FIG. 7c is similar to that of FIG. 7b, whereby here several loops 62, 63 are formed, said loops being arranged next to each other in a direction transverse to the flow space 21 and connected to each other.

[0088] Furthermore, FIGS. 7d- 7f show embodiments, wherein the spiraliform, stelliform or serpentine courses of the liquid channels 27 and the outlets 38 each have several straight line sections 64 with interposed curved or arcuate connecting sections 65. As in the embodiments mentioned hereinabove, the courses may be two-dimensional or three-dimensional.

[0089] Advantageously in all embodiments, an elongated, continuous, kink-free course with a plane of projection is obtained that extends along or covers a large portion of the flow space 17 or the plane of projection. The great length of the liquid channel 27 and the outlet openings 38 allows—even with a highly limited gap width—an adequate amount of liquid to discharge in the form of an elongated, uniform, thin liquid film out of the outlet opening to be subsequently effectively atomized.

[0090] The nozzle opening 17 forming the outlet of the nozzle 10 preferably has essentially the same form as the line of projection of the liquid channel 27 and the outlet opening 38, however, it may also be different therefrom.

[0091] Furthermore, as also depicted in FIGS. 7a-7f, the flow space 21 may have various desired forms—preferably cylindrical or tubular—with, for example, a circular, oval, square, rectangular or any other suitable cross-section.

[0092] From the foregoing, a pneumatic atomizing nozzle 10 is provided, which preferably can be supplied with gas and operated by means of a fan 43. The pneumatic atomizing nozzle 10 has a nozzle body 11, which bounds a flow space 21. The pneumatic atomizing nozzle 10 also has a liquid channel 27 having an outlet opening 38. Within the flow space 21, a liquid film 41 is formed, which is transported within the flow space 21 to the nozzle outlet 17 by the gas flow. The outlet opening 38 of the liquid channel 27 defines an outlet direction A for the liquid into the flow space 21, which outlet direction preferably is opposite the flow direction S of the liquid film 41. At least in some sections, the liquid channel 27 and the outlet opening 38 thereof preferably extend transversely through the nozzle body 11 in a curved, wound, or meandering manner.

TABLE-US-00001 List of Reference Signs: 10 Atomizing nozzle 11 Nozzle body 12 First face side 13 Second face side 14 Gas connection 16 Liquid connection 17 Nozzle outlet, nozzle orifice 18 Gas channel 19 Wall 21 Flow space 22 Spiral wall 23 Inlet side 24 Front section 26 Rear section 27 Liquid channel 28 Supply section 29 Supply channel wall 31 Outlet section  31a First mounting point  31b Second mounting point 32 First channel wall 33 Second channel wall 34 First wall outside surface 35 Second wall outside surface 36 Guide body 37 Outlet side 38 Outlet opening 39 Stripping side 40 Tearing edge 41 Liquid film 42 Nozzle device 43 Fan 44 Pump 46 Water source, liquid supply 50 Method 51-55 Method steps 61-63 Loops 64 Straight line sections 65 Connecting sections Z Cylinder axis U Circumferential direction H Spiral arm height A Outlet direction S Flow direction K Channel direction