FOG INJECTION NOZZLE

Abstract

A fog injection nozzle able to generate a swirling cone of fog. The nozzle includes an internal cavity into which a pressurized liquid and a pressurized gas are introduced. The pressurized liquid is introduced into the cavity via a central axial duct of a cylindrical block and the pressurized gas is introduced into the cavity via a plurality of axial through holes disposed about the central axial duct. The axial through holes and radial arms are arranged such that a mixture of the liquid and gas inside the cavity is asymmetrically deflected by the radial arms to cause a swirling tangential component to appear in the conical flow of fog discharged from the nozzle.

Claims

1. A fog injection nozzle comprising: a body provided with a first axial cavity and a second axial cavity, the second axial cavity located forward of the first axial cavity; a first duct that traverses the first axial cavity and is configured to carry a liquid in a forward direction; a second duct configured to carry a gas into the first cavity; a block located in a forward end of the first axial cavity and provided with a central axial duct fluidly connected to a front end of the first duct. the block having a central axis and further including at least first and second axial holes fluidly connecting the first cavity with the second cavity for the passage of the gas, the first and second axial holes being spaced from the central axis and angularly equidistantly-spaced apart from one another; an axial outlet duct located forward of the second axial cavity and configured to receive a mixture of the liquid and the gas; and an outlet pin located in the axial outlet duct, a front end of the outlet pin including an axial stem provided with a widening located at or near a front end of the axial outlet duct, a rear end of the outlet pin including a transverse disc that is connected to a rear end of the axial stem by at least first and second radial arms that are angularly equidistantly-spaced apart from one another, the first and second radial arms being respectively arranged forward of the first, and second axial holes of the block, a shape of each of the first and second radial arms in conjunction with their arrangement with respect to the first and second axial holes results in the mixture of the liquid and gas located in the second axial chamber to be asymmetrically diverted to first and second lateral sides of each of the first and second radial arms or to be diverted to only one lateral side of the first and second radial arms to produce a rotating conical flow of fog at a nozzle outlet upon the liquid and gas being introduced into the body.

2. The fog injection nozzle according to claim 1, wherein a central axis of each of the first and second axial holes is respectively misaligned with an axis of each of the first and second radial arms so that the mixture of the liquid and gas located in the second axial chamber is asymmetrically diverted to the first and second lateral sides of each of the first and second radial arms.

3. The fog injection nozzle according to claim 1, wherein a section of each of the first and second radial arms upon which the mixture of the liquid and gas impinges includes a central spike.

4. The fog injection nozzle according to claim 3, wherein the central spike has a convex shape.

5. The fog injection nozzle according to claim 1, wherein a section of each of the first and second radial arms upon which the mixture of the liquid and gas impinges comprises the first and second lateral sides, the first lateral side being curved, the second lateral side being flat.

6. The fog injection nozzle according to claim 5, wherein a central axis of each of the first and second axial holes is respectively aligned with an axis of each of the first and second radial arms.

7. The fog injection nozzle according to claim 1, wherein each of the cylindrical block and second axial cavity has a cylindrical shape.

8. The fog injection nozzle according to claim 1, wherein the body is divided along an axial plane into a first body portion and a second body portion.

9. The fog injection nozzle according to claim 8, wherein the first and second body portions respectively comprise first and second flat axial faces and are joined by a plurality of screws that extend across the first and second flat axial faces.

10. The fog injection nozzle according to claim 8, wherein the first and second body portions respectively comprise first and second flat axial faces, at least one of the first and second axial faces including a channel in which resides a sealing gasket, the sealing gasket and channel being configured such that when the first and second body portions are joined, two gaps are produced between the first and second body portions near the axial outlet duct to permit the mixture of the liquid and gas to escape the body at high speed.

11. The fog injection nozzle according to claim 1, wherein the first and second axial holes of the block are each straight and arranged parallel to one another.

12. The fog injection nozzle according to claim 1, wherein the first and second axial holes and the central axial duct of the block are each straight and arranged parallel to one another.

13. The fog injection nozzle according to claim 1, wherein the block includes a third axial hole and the output pin includes a third radial arm, the third axial hole and third radial arm configured to function together to cause a portion of the mixture of the liquid and gas located in the second axial chamber to be asymmetrically diverted to first and second lateral sides of the third radial arm or to be diverted to only one lateral side of the third radial arm.

14. The fog injection nozzle according to claim 2, wherein a section of each of the first and second radial arms upon which the mixture of the liquid and gas impinges includes a central spike.

15. The fog injection nozzle according to claim 2, wherein each of the cylindrical block and second axial cavity has a cylindrical shape.

16. The fog injection nozzle according to claim 2, wherein the body is divided along an axial plane into a first body portion and a second body portion.

17. The fog injection nozzle according to claim 16, wherein the first and second body portions respectively comprise first and second flat axial faces and are joined by a plurality of screws that extend across the first and second flat axial faces.

18. The fog injection nozzle according to claim 16, wherein the first and second body portions respectively comprise first and second flat axial faces, at least one of the first and second axial faces including a channel in which resides a sealing gasket, the sealing gasket and channel being configured such that when the first and second body portions are joined, two gaps are produced between the first and second body portions near the axial outlet duct to permit the mixture of the liquid and gas to escape the body at high speed.

19. The fog injection nozzle according to claim 2, wherein the first and second axial holes of the block are each straight and arranged parallel to one another.

20. The fog injection nozzle according to claim 1, wherein the first and second axial holes and the central axial duct of the block are each straight and arranged parallel to one another.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0027] FIG. 1 shows a longitudinal section of a prior art nozzle described in EP3395449.

[0028] FIG. 2 shows a perspective view of a scroll module of the nozzle of FIG. 1.

[0029] FIG. 3 shows a perspective view of a nozzle pin of the nozzle of FIG. 1.

[0030] FIG. 4 shows a perspective view of a nozzle according to one embodiment.

[0031] FIG. 5 shows another perspective view of the nozzle of FIG. 4.

[0032] FIGS. 6A and 6B respectively show first and second body portions of the nozzle of FIG. 4.

[0033] FIG. 7 shows a longitudinal sectional view of the nozzle of FIG. 4.

[0034] FIG. 8 shows a perspective view of a cylindrical block shown in FIG. 7.

[0035] FIG. 9 shows a perspective view of an outlet pin shown in FIG. 7

[0036] FIGS. 10A and 10B respectively show an axial view from the outlet end of the nozzle and a section through an axial hole of the cylindrical block when axial holes and radial arms are aligned.

[0037] FIGS. 11A and 11B respectively show an axial view from the outlet end of the nozzle and a section through an axial hole of the cylindrical block when axial holes and radial arms are misaligned.

[0038] FIGS. 12A-12C show the effect of angular misalignment between axial holes of the cylindrical block and radial arms according to one embodiment.

[0039] FIGS. 13A-13B show the effect of the shape of the radial arms when axial holes and radial arms are aligned according to a second embodiment.

DETAILED DESCRIPTION

[0040] The present invention is herein described with reference to FIGS. 4-13 attached.

[0041] The nozzle (1) of the present invention is formed by a body (2) which is formed by two halves (21a, 21b) separated along a flat axial face. The two halves (21a, 21b) have two rows of three holes (22) arranged along the side walls of their respective flat axial face for fixing by means of screws (14). An additional piece (13) in the form of a transverse disc is fixed, also by means of screws (15), to the rear end of the body (2) of the nozzle (1). Furthermore, the peripheral walls of the flat axial face of the first half (21) are traversed by a channel (12) for receiving a seal (not shown). An adequate selection of the tightening force of the screws (14) causes that, during the use of the nozzle (1), a small part of air escapes through the slot closed by the sealing gasket. This small air leak causes an enhancing effect on the rotational properties of the emitted fog, as will be described in greater detail later in this document.

[0042] The transverse disc (13) that closes the rear end of the body (2) comprises, on its front face, an axial conduit (4) for liquid that runs through a first cylindrical cavity (3) of the nozzle (1) whose diameter is substantially greater than that of said axial duct (4). At its rear end, the axial liquid conduit (4) is connected to a pressurized liquid inlet port (5). The liquid inlet port (5) is formed on a rear side of the transverse disc (13) itself. At its front end, this axial liquid conduit (4) is joined to an axial conduit (81) of a cylindrical block (8) located inside a housing (16) adjacent to the front end of the first cavity (3). The gas inlet to the nozzle (1) takes place in a radial direction through a gas inlet port (6) connected to the first cavity (3) through a radial duct (7).

[0043] Therefore, the liquid introduced through the inlet port (5) runs through the axial conduit (4), passes through the axial conduit (81) of the cylindrical block (8) that covers the front side of the first cavity (3), and exits into a second cylindrical cavity (9) through the front end of said axial duct (81). The cylindrical block (8) also has three axial holes (82) radially separated from the central axis (E) and equally spaced angularly. These axial holes (82) join the first cavity (3) with a second cavity (9) located on the front side of the cylindrical block (8). In this way, the pressurized gas that is introduced into the first cavity (3) through the inlet port (6) passes, through said axial holes (82), to the second cavity (9). Therefore, in the second cavity (9) the interaction between the pressurized gas flow and the pressurized liquid flow takes place. In particular, the pressurized liquid flow emitted through the axial conduit (81) impacts against a rear end surface of an output pin (10), which is described later, fragmenting into small size particles. The pressurized gas injected through the axial holes (82) then entrains these particles through an axial outlet duct (11) of the nozzle (1) located on the front side of the second cavity (9).

[0044] The axial duct (11) takes the form of a nozzle whose section is decreasing in a first section, and increasing in the second section, thus connecting the second cavity (9) with the outside of the nozzle (1). Inside the axial duct (11) there is an outlet pin (10) that guides the fog flow to generate a rotating conical flow at the outlet of the nozzle. The output pin (10) is basically formed by an axial rod (101) located on its front side and connected to a hollow transverse disc (103) located on its rear side. The axial stem (101) has a first portion that narrows to run through the first section of the nozzle with a decreasing section of the axial duct (11) parallel to its walls. A second portion of the axial stem (101) is formed by a widening (102) that runs through the second section of the nozzle with an increasing section of the axial duct (11) also parallel to its walls. For its part, the hollow transverse disc (103) is connected to the rear end of the axial stem (101) through three radial arms (104) equally spaced angularly. As can be seen, the rear surface of the radial arms (104) has a flat cross-sectional shape. Furthermore, the distance between the axial holes (82) of the cylindrical block (8) and the main axis (E) of the nozzle (1) is selected such that the axial holes (82) are located opposite the area of the arms radials (104) of the hollow transverse disc (103).

[0045] Thus, when the cylindrical block (8) and output pin (10) are angularly aligned, the flow emitted through each axial hole (82) impacts the center of a respective radial arm (104). This situation is shown in greater detail in FIGS. 10A and 10B. Specifically, in the section of FIG. 10B it can be seen how the axis (E82) of the axial hole (82) is completely aligned with the axis (E104) of the radial arm (104) located opposite it. The pressurized air flow injected through the axial hole (82) thus impacts the center of the corresponding radial arm (104), and is divided on each side thereof into two approximately equal portions. In this situation, no radial component is generated in the fog emitted at the outlet of the nozzle (1).

[0046] In contrast, FIGS. 11A and 11B show a situation where the cylindrical block (8) is not angularly aligned with the output pin (10). There is a small angular difference between them, so that the axis E82 of each axial hole 82 is offset relative to the axis E104 of the radial arm 104 located opposite it. Naturally, the magnitude of this deviation is less than the diameter of the axial hole (82) itself, so that at least part of the flow of pressurized air injected through each axial hole impacts against the corresponding radial arm (104). In this situation, the symmetry present in the case described in the previous paragraph is lost, the pressurized air flow does not impact against the center of the corresponding radial arm (104), and is therefore divided into two different portions. In this specific case, as shown in FIG. 11B, the portion of flow passing through the left side of the axial arm (104) is substantially larger than the portion of flow passing through the right side of the axial arm (104). This causes the appearance of a tangential component to the left, thus generating the rotating effect in the fog cone emitted by the nozzle (1).

[0047] In the previous figures, the rear surfaces of the radial arms (104) have been shown as flat. This causes high losses due to the impact of the flow emitted through the axial holes (82) against said flat surfaces perpendicular to the main direction of the flow. To avoid this, it is possible to provide the rear surfaces of the radial arms 104 with a specially designed shape to reduce losses. For example, as shown in FIGS. 12A-12C, the rear surfaces of the radial arms (104) may be formed by a raised central rib (104a) parallel to the edges of the respective radial arm (104) descending along two lateral valleys (104b).

[0048] Thus, as shown in FIG. 12A, when the cylindrical block (8) is aligned with the output pin (10), the flow injected through the axial holes (82) is separated without great losses by the rib (104a) in two essentially equal portions running through the lateral valleys (104b). In this situation, no rotating effect is generated in the fog cone emitted at the outlet of the nozzle (1).

[0049] In contrast, FIGS. 12B and 12C show respective situations in which the cylindrical block (8) is not aligned with the output pin (10). In that case, the rib 104a divides the flow injected through the axial holes (82) into two different portions. Specifically, in FIG. 12B the portion of flow descending along the right lateral valley (104b) is much larger than the portion of flow descending along the left lateral valley (104b). Similarly, in FIG. 12C the portion of flow descending along the left lateral valley (104b) is much larger than the portion of flow descending along the right lateral valley (104b). In these cases, the rotating effect is generated in the fog cone emitted at the outlet of the nozzle (1).

[0050] Lastly, FIGS. 13A and 13B show another example of the shape that the rear surfaces of the radial arms (104) can have. In these cases, the raised rib (104c) is not located in the center of the respective arm (104), but is located on one of its sides. Specifically, it is the enlargement of one of the lateral faces of the arm (104), so that the raised rib (104c) is formed by the edge itself. From this rib (104c), the rear surface of the arm descends to the right (FIG. 13A), or to the left (FIG. 13B). This configuration of the radial arms (104) allows the rotational effect to be generated in the fog at the outlet of the nozzle (1) without the need to angularly misalign the cylindrical block (8) and the outlet pin (10). Indeed, with the axial holes (82) aligned with the respective arms (104), the upper surfaces of the radial arms (104) designed in this way direct all of the flow injected through said radial holes (82) well to the right (FIG. 13A) or to the left (FIG. 13B). This configuration has the additional advantage that it allows the magnitude of the rotating effect to be maximized, since it allows all the entire injected flow to be diverted on one or the other side of the radial arm. (104).

[0051] In addition, as mentioned previously in this document, in any of the described configurations it is possible to increase the gradient effect printed on the fog cone at the nozzle (1) outlet thanks to a suitable selection of the sealing gasket and the tightening force of the screws (14) that join the two halves (21a, 21b) of the body (2) of the nozzle (1). Indeed, when the continuity of the sealing joint is interrupted near the outlet duct (11), two gaps are produced between the two parts of the assembly through which the fog can escape at high speed. As it occurs only at two angles, it increases the angular asymmetry and therefore the velocity gradients in the fluid-fog-that escapes, which makes it easier to attract surrounding air and trap suspended particles.