GB2135215A - Spray nozzle - Google Patents

Abstract

A spray nozzle adapted to spraying in a square pattern comprises an aperture 1 and four grooves 3 in a face 2 of the nozzle, said grooves extending tangentially to the aperture. The mouth of the aperture may be circular or square. Upstream of the aperture a swirl chamber may have tangential and axial inlets, or a deflector with inclined surfaces (13, Fig. 6) to produce a turbulent axially swirling flow. <IMAGE>

Description

SPECIFICATION Spraying apparatus This invention relates to apparatus for spraying liquids particularly but not exclusively for producing a rectangular or square spray or liquid. The apparatus finds particular use in spraying water for horticultural purposes in which it is important that an area is completely wetted in an even manner. The apparatus may also find use where an even pattern is required to be sprayed in lines, for example line markings, continuous cooling or fire protection.

According to the present invention a spray nozzle comprises an aperture and four grooves in a face of the nozzle, said grooves extending tangentially to the aperture.

Preferably each groove is generally perpendicular to adjacent grooves.

Liquid passed through an aperture tends to rotate producing a swirling effect. Provision of four grooves tangential to the aperture causes preferential conduction of the spray in the direction of the grooves; in the preferred instance, towards the corners of a square. Movement of air due to the spray conducted in the preferred directions causes a slipstream effect. Components of the spray adjacent to the preferred directions are caused to extend a greater distance from the nozzle than components of the spray in intermediate directions which are not adjacent to the preferred directions.

The grooves are preferably curved. In this case the curvature is preferably in the same direction as the swirling effected caused by the aperture.

The diameter of the aperture preferably increases towards the said face of the nozzle. The aperture may be generally conical but flaring at the broad end or may be trumpet shaped. Alternatively, the aperture may be square or rectangular in plan view, flaring towards the face of the nozzle, preferably the aperture is profiled to be parabolic in vertical longitudinal cross-section and forming a continuous surface with the said face.

In preferred embodiments of the invention the face of the nozzle is square in shape with the grooves extending tangentiallyfrom a central aperture toward the vertices of the square.

Preferably the entire face of the nozzle is square in plan view and curved towards the aperture in cross sectional view. The angle of the periphery of the face relative to the aperture is therefore greatest at the apexes of the square. Preferably the grooves are arranged in use to subtend an angle of 45" to the axial direction which is preferably vertical at the point of ejection of the spray. The spray may be ejected from the grooves at the apexes of the square.

The nozzle is preferably arranged to be located in use with aperture extending vertically. Liquid passed through the aperture is ejected parallel to the face of the nozzle at an angle to the horizontal dependent on the curvature of the face. The angle of ejection is therefore greatest in conical or trumpet shaped apertures at the mid points between the apexes. The latter angle may be 60". Liquid ejected from the nozzle along the grooves at an angle of 45" travels the greatest horizontal distance and liquid ejected intermediate the grooves travels a shorter horizontal distance dependent on the angle of ejection. The nozzle therefore produces a generally square pattern of spray.

A nozzle in accordance with the invention may further comprise a swirl chamber located in use upstream of the said aperture. The swirl chamber may be cylindrical with the aforesaid aperture extending axially therefrom may have inlets from the axis, for example radially extending inlets. An additional inlet may be located axially, remote from the aperture. The additional inlet serves to provide an axially directed jet of liquid which prevents a hollow vortex from occurring in the aperture and thereby increases the turbulence in the aperture causing a decrease in the velocity of the sprayed liquid. This serves to produce a full cone spray having larger droplets which may travel further than smaller ones.

An alternative embodiment may have a swirl chamber containing a deflector having one or more surfaces inclined to the direction of flow of liquid into the chamber. The one or more surfaces are preferably arranged to deflect liquid in a swirling direction in the chamber. The deflector may alternatively have a helical, double helical or screw shaped surface.

More than one swirling chamber may be employed.

The apparatus may be arranged for fixture in use upon the end of a vertically extending pipe. A number of such pipes may be arranged so that square sprays produced by respective nozzles cover the entire area between the pipes.

The nozzle may incorporate means for securing it upon a pipe without recourse to a screw thread. The said means may comprise a sealing ring arranged to bear against a conical interior surface of the apparatus as the latter is urged away from the pipe.

The invention will now be further described by way of example with reference to Figures 1 to 8 of the accompanying drawings, of which: Figure 1 is a cross section of a spray head; Figure 2 is a plan view of the spray head; Figure 3 is an enlarged partial cross section of the spray head; Figure 4 is an enlarged partial plan view of the spray head; Figure 5 is an enlarged partial plan view of an alternative spray head; and Figures 6to 8 illustrate a deflector for use in the swirl chamber.

The spray head shown in cross-section in the Figures comprises a nozzle having a trumpet-shaped aperture 1 which expands towards the face 2 of the nozzle. The aperture includes four grooves 3 disposed tantentially to the inlet 4 of the aperture. The grooves are not shown in Figure 1 and 2 for clarity.

Each groove 3 extends clockwise in a curved direction around the aperture 1.

The angle of ejection of the spray at the mouth of the trumpet shaped aperture 1 is chosen to be 402 to the vertical. The angle subtended at the point of ejection of each groove is chosen to be 45" to the vertical so that the trajectory of the ejected liquid is greater for the portion of the spray emanating from the grooves.

A swirl chamber 5 is disposed below the aperture 1 and incorporates two peripheral inlets 6 and an axial inlet 7. The peripheral inlets 6 serve to cause water passed into the spray head to enter the swirl chamber5 and rotate within it. The axial inlet 7 serves to reduce the tendency for a hollow spray to emanate from the aperture 1 and also produces turbulence in the aperture to reduce the velocity of the spray.

The body 8 of the spray head includes a push-on sealing assembly comprising a sealing ring 9 which co-operates with a conical surface 9. The sealing ring may take the form of an O-ring as shown in cross-section at 10, or a tapered seal as shown in cross-section at 11.

In use of the spray head, the latter may be pushed onto the outlet of a pipe (not shown) so that the conical surface 9 causes the sealing ring to bear against the pipe as the spray head is urged for example by water pressure, saway from the end of the pipe.

Figure 5 shows an alternative spray head in which the mouth 10 of the aperture 11 is generally square in shape, the four grooves 12 being directed towards the vertices of the square.

Figures 6 to 8 show a deflector which may be used in a swirl chamber of an alternative embodiment of this invention, Figures 6 and 7 being front and side elevations and Figure 8 being a plan view. The deflector which may be placed in a cylindrical cavity, comprises two surfaces 13 inclined with respect to the direction of flow of liquid, the latter being axially from below as shown in Figures 6 and 7.

Liquid passing over the surfaces 13 is further deflected through apertures 14, producing a turbulent, axially swirling fiow. The deflector may be located in a generally cylindrical chamber upstream from the nozzle. Any other helical, double helical or screw-shaped deflector may be employed.

Claims (16)

1. A spray nozzle comprising an aperture and four grooves in a face of the nozzle, said grooves extending tangentially to the aperture.

2. A spray nozzle as claimed in Claim 1, wherein the aperture is arranged in use in a vertical direction.

3. A spray nozzle as claimed in claim 1 or 2 wherein each groove is perpendicuiarto adjacent grooves.

4. A nozzle as claimed in any of claims 1 to 3 wherein the grooves are curved.

5. A nozzle as claimed in any preceding claim, wherein the diameter of the aperture increases towards the face of the nozzle.

6. A nozzle as claimed in claim 4, wherein the aperture is either rectangular in plan view of generally conical but flaring at the broad end.

7. A nozzle as claimed in claim 5 or 6, wherein the profile of the aperture is parabolic in longitudinal cross section and forms a continuous surface with said face.

8. A nozzle as claimed in any preceding claim, wherein the face of the nozzle is square and the grooves extend tangentially from a central aperture toward the vertices of the square.

9. A nozzle as claimed in any preceding claim, wherein the grooves are arranged in use to subtend an angle of 45" to the vertical.

10. A nozzle as claimed in any preceding claim, comprising a swirl chamber located in use upstream of the said aperture.

11. A nozzle as claimed in claim 10, wherein the swirl chamber comprises one or more inlets spaced from the axis of the chamber.

12. A nozzle as claimed in claim 11, comprising an additional axial inlet.

13. A nozzle as claimed in claim 10, wherein the swirl chamber contains a deflector having or or more surfaces inclined to the direction of flow into the chamber.

14. A nozzle substantially as herein before described with reference to Figures 1 to 4 of the accompanying drawings.

15. A nozzle substantially as hereinbefore described with reference to Figure5 of the accompanying drawings.

16. A nozzle substantially as hereinbefore described with reference to Figures 6 to 8 of the accompanying drawings.