NOZZLE FOR SPRAYING AN INORGANIC MASS

Abstract

The invention pertains to a nozzle for spraying and inorganic mass with the following characteristics: a flow channel (10) that extends from a first end (12) with an essentially circular cross section to a second end (14) with an essentially slot-like cross section. The respective minimum cross section of the flow channel (10) changes from a circular to a reniform and ultimately to a slot-like cross section between the first end (12) and the second end (14), and the flow channel extends between the first end (12) and the second end (14) in such a way that an axis (x) extending perpendicular to the circular cross section on the first end (12) and through its center of area is spaced apart from the center of area of at least 50% of the reniform cross sections of the flow channel (10).

Claims

1. A nozzle for spraying an inorganic mass with the following characteristics: a flow channel (10) that extends from a first end (12) with an essentially circular cross section to a second end (14) with an essentially slot-like cross section, the respective minimal cross section of the flow channel (10) changes from a circular to a reniform and ultimately to a slot-like cross section between the first end (12) and the second end (14), wherein each reniform cross section features at least one concavely and one convexly curved circumferential segment.

2. The nozzle according to claim 1, in which the flow channel extends between the first end (12) and the second end (14) in such a way that an axis (x) extending perpendicular to the circular cross section at the first end (12) and through its center of area, is spaced apart from the center of area of at least 30% of the reniform cross sections of the flow channel (10).

3. The nozzle according to claim 1, in which the cross section of the flow channel (10) at the second end (14) is no more than 20% smaller than the cross section of the flow channel (10) at the first end (12).

4. The nozzle according to claim 2, in which the axis (x) extending perpendicular to the circular cross section at the first end (12) and through its center of area, also extends through the center of area of the slot-like cross section of the flow channel (10) at the second end (14).

5. The nozzle according to claim 2, in which the axis (x) extending perpendicular to the circular cross section at the first end (12) and through its center of area, lies outside the slot-like cross section of the flow channel (10) at the second end (14).

6. The nozzle according to claim 1, in which the flow channel (10) extends in an arched fashion at least along one segment (10w) between the first end (12) and the second end (14).

7. The nozzle according to claim 1, in which the flow channel (10) extends in an arched fashion in a segment (10w) with reniform cross sections.

8. The nozzle according to claim 1, in which the flow channel (10) extends linear in an intake section that follows the first end (12).

9. The nozzle according to claim 1, in which the flow channel (10) extends linear in an end section leading to the second end (14).

10. The nozzle according to claim 1, in which the slot-like cross section of the flow channel at the second end (14) has a height (H) that amounts to 0.7-times to 0.1-times the diameter (D) of the circular cross section at the first end (12).

11. The nozzle according to claim 1, in which the reniform cross sections respectively feature just one concave, inwardly curved circumferential segment.

12. The nozzle according to claim 1, in which the concave and convex circumferential segments of the reniform cross sections of the flow channel (10) respectively extend over an angle of 30 degrees referred to the center of area of the respective reniform cross section.

13. The nozzle according to claim 1, in which the convex circumferential segments of the reniform cross sections of the flow channel (10) respectively extend over an angle of more than 210 degrees referred to the center of area of the respective reniform cross section.

14. The nozzle according to claim 1, in which the reniform cross sections of the flow channel (10) respectively feature a circumferential segment, the average curvature radius of which is smaller than twice the diameter of the circular cross section at the first end (12) of the flow channel (10).

15. The nozzle according to claim 1, which is made of at least one inorganic material of the group comprising: earthenware, stoneware, porcelain, corundum, metal carbide and metal nitride

Description

[0060] The invention is described in greater detail below. To this end, two exemplary embodiments are illustrated in the drawings, wherein

[0061] FIG. 1a shows a side view of a first embodiment of a nozzle,

[0062] FIG. 1b shows cross sections through the flow channel of the nozzle according to FIG. 1a at corresponding locations (broken lines) indicated in FIG. 1a,

[0063] FIG. 1c shows a perspective view of the nozzle according to FIG. 1a,

[0064] FIG. 2a shows a side view of a second embodiment of a nozzle,

[0065] FIG. 2b shows cross sections through the flow channel of the nozzle according to FIG. 1a at corresponding locations (broken lines) indicated in FIG. 2a, and

[0066] FIG. 2c shows a perspective view of the nozzle according to FIG. 2a.

[0067] FIG. 1 shows a first embodiment of an inventive nozzle for atomizing a refractory inorganic mass.

[0068] The nozzle (generally identified by the reference symbol N) features a flow channel 10 that is schematically illustrated in the form of a dot-dash line in FIG. 1a and extends from a first end 12 of the nozzle N to a second end 14 of the nozzle N.

[0069] Along the flow direction of the nozzle N the flow channel therefore essentially has five zones N1, N2, N3, N4, N5, which are indicated by horizontally extending lines in FIG. 1c.

[0070] In this case, the flow channel 10 has the following cross sections in the zones N1-N5 (respectively referred to the flow direction of the mass to be sprayedarrow S):

N1: a circular cross section on the first end 12 as illustrated in FIG. 1b; the round cross section transforms into an oval cross section shortly before the beginning of zone N2 and into a reniform cross section with an indentation E (a convex surface section) on one side (bottom of FIG. 1b) at the transition to N2;
N2: the reniform cross section continues, but becomes increasingly thinner and wider; it can be gathered that the curvature radius of the concave (upper) segment of the flow channel cross section increases in zone N2;
N3: the reniform cross section continues, but becomes even thinner and wider; the reniform cross section is furthermore characterized by a convex segment (bottom) and a concave segment (top) with relatively large curvature radius;
N4: the cross section already changes from a distinct reniform cross section toward a slot-like cross section shortly before the transition to N4, wherein the indentation E only marginally (slightly) protrudes inwardly at this point and almost entirely disappears at the transition to N5;
N5: shortly after the beginning of N5, the cross section is exactly rectangular and the flow channel therefore has the shape of a slot at this point, wherein the ratio of width (B) to height (H) amounts to 8:1 and opposing wall surfaces of the flow channel extend parallel to one another. The flow channel 10 therefore has the shape of a slot with a rectangular cross section on the second end.

[0071] The axial length of each of the zones N1-N5 amounts to approximately 20% in this case.

[0072] Three different reniform cross sections, which are respectively characterized by an indentation E, are illustrated in an exemplary fashion in FIG. 1b.

[0073] FIG. 1a, in particular, shows that the flow channel 10 does not extend linear, but rather features an arched segment, which is identified by the reference symbol 10w and particularly extends over the zones N2 and N3, approximately in the center between the first end 12 and the second end 14 of the nozzle N.

[0074] The flow channel 12 has a reniform cross section in this segment 10w (see FIG. 1b).

[0075] All in all, the flow channel 10 extends in such a way that an axis extending perpendicular to the circular cross section of the first end 12 and through its center of area is vertically offset with respect to the reniform cross sections of the flow channel (i.e. spaced apart from the center of area of the majority of reniform cross sections), but once again extends centrally in the slot-shaped channel segment at N5.

[0076] In FIG. 1b, the respective intersecting point of this (imaginary) axis is indicated with x.

[0077] A refractory ceramic mass which is to be sprayed and which is introduced into the nozzle N at 12, is transported through the flow channel 10 and in the segments with reniform cross section it is at least partially deflected outwardly (due to the respective indentation E) in order to be ejected from the second end 14 in the form of a compact fan jet.

[0078] The embodiment according to FIG. 2 is similar to the embodiment according to FIG. 1 such that only the differences between the two embodiments are described below:

[0079] In this embodiment, the second end 14 is offset to the first end 12, i.e. an axis extending perpendicular to the circular cross section of the first end 12 and through its center (=center of area) lies outside the slot-like cross section of the flow channel 10 of the second end 14 (in segments N4 and N5), wherein this is once again indicated with x in FIG. 2b analogous to FIG. 1.

[0080] The lateral offset of the flow channel is realized such that the aforementioned axis is already spaced apart from the flow channel 10 shortly before the slot-shaped end section (i.e. in the zone N4).

[0081] In both embodiments, the mass to be sprayed is additionally mixed and homogenized due to the axial extent of the flow channel 10 with an arched segment 10w such that an optimized spraying result is achieved.

[0082] Since the mass to be sprayed is ejected from the second end 14 of the nozzle N in the form of a fan jet (similar to a curtain), the thusly sprayed wall coating has homogenous and uniform material properties, as well as a largely constant thickness.