GB2024659A

GB2024659A - Spray nozzle

Info

Publication number: GB2024659A
Application number: GB7926834A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-09
Filing date: 1979-08-01
Publication date: 1980-01-16
Also published as: GB2024659B

Abstract

A spray nozzle, particularly suitable for dust suppression duties, has a body 10 with an axial opening 14 in which is located a valve member 23 which is movable to vary the rate of flow of spray fluid, and together with the body defines an annular flow path which converges on the outlet 16. The flow path comprises two generally conical parts of different angles. The valve member 23 is threadedly engaged in the body and is adjustable by means of a tool inserted in hexagonal bore 25. The valve also has a flexible sleeve 33 which prevents flow until the water pressure reaches a predetermined level. The arrangement enables unblocking of the outlet to be easily achieved and loss of water from the nozzle is prevented when the supply is turned off. <IMAGE>

Description

SPECIFICATION Spray nozzle This invention relates to spray nozzles and particularly, but not exclusively, to spray nozzles for directing a spray of water for suppressing dust.

Spray nozzles have particular application in mines where airborne dust is a health hazard and where spray nozzles are fitted to mining machines to suppress the production of dust at its source.

Present spray nozzles can become blocked due to the accumulation of material in the nozzle outlet and it is difficult to unblock the nozzles. Moreover, spray nozzles release water in the conduits to the nozzles after the water supply is interrupted and, when the supply is restored, there is a delay before the spray is re-established because the conduit has first to be refilled with water. Such a delay means that either the operation of the mining machine is delayed until the spray is established or the machine is operated for a period without any spray being operative.

With these and other problems in mind the object of the invention is to provide a spray nozzle which gives more effective operational characteristics.

According to one aspect of the invention a spray nozzle comprises a body member having an opening extending between a fluid outlet and a fluid inlet, a movable valve member located in the opening and defining with the body member adjacent the outlet a fluid flow path which is generally annular and converges towards the outlet, the valve member being movable to vary the cross-section of said flow path.

Preferably the cross-section of said fluid flow path varies so that the cross-section is wider over a portion of the path nearest to the outlet than over a portion remote from the outlet and said fluid flow path is generally conical, the outlet being located at the apex of the cone.

Conveniently the cone is in two contiguous portions having different cone angles, the portion adjacent the outlet having a greater cone angle than the other portion.

The valve member may be in screw-threaded engagement with the opening in the body member and movable towards and away from the outlet by relative rotation of the valve and body members to vary the cross-section of said flow paths.

According to another aspect of the invention a spray nozzle comprises a body member having an opening extending between a fluid inlet and a fluid outlet, a valve member located in the opening and formed with duct means communicating at one end with the inlet, and a resilient obturating means obstructing the other end of the duct, the obturating member preventing flow of fluid from the inlet through the duct and towards the outlet until the fluid pressure in the duct exceeds a predetermined value.

Preferably the obturating member is in the form of a resilient sleeve located around a cylindrical portion of the valve member.

Conveniently the duct means includes a longitudinal bore leading to a transversely extending bore or bores opening to the outer surface of the cylindrical portion, the sleeve being located over the end or ends of the transverse bore or bores.

Further features of the invention will appear from the following description of an embodiment of the invention given by way of example only and with reference to the drawing which is a longitudinal section through a spray nozzle.

Referring to the drawing a spray nozzle for fitment to a mining machine is shown which has a body member 10 externally threaded with a tapered thread 11 and having a head 12 formed with hexagonal surfaces 13 for engagement by a spanner.

The body 10 is arranged for location in a threaded socket (not shown) to the base of which water can be introduced for passage into the nozzle.

The body 10 is generally cylindrical and has an axial opening 14 one end of which constitutes an outlet 15 for water and at the other end is an outlet opening 16 in the form of a circular passage. The passage 16 leads into an inverted, generally coneshaped portion 17 of the opening 14 and a threaded portion 19. The remainder of the opening 14 is in the form of a cylindrical portion 20 having a shoulder 20A and a groove 20B.

The passage 16 is at the apical end of the portion 17 and the portion 17 is in two parts, a part 17A nearest the passage 16 having a wider cone angle than the other part 17B.

Located within the opening 14 is a valve member 23 having a generally conical nose 24 in the centre of which is formed an axial bore 25 of hexagonal section for receiving a turning tool (not shown) inserted through the outlet 16. The member 23 is formed with a cylindrical screw-threaded portion 26 extending from the portion 24 and in screw-threaded engagement with the portion 19 of the body 10.

The conical nose 24 is in two parts of different cone angles, a radially inner part 24A of wider cone angle, corresponding to that of the part 17A, and an outer part 24B of narrower cone angle. The parts 1 7A and 24A and 17B and 24B are arranged to provide a passage of narrower width over the parts 17B and 24Bthan over the parts 17Aand 24A. Overthe conical parts 17 and 24 of the body member and the valve member there is defined a generally annular path for water passing to the outlet, the path converging towards the outlet 16. As will become clear the cross-sectional area of this path can be altered by rotating and moving the valve member towards and away from the outlet 16.Such movement may be from a no-flow condition in which the path is not open, to a full flow condition giving a maximum cross-sectional area of the path. It will be appreciated that although the path defined by 17B and 24B is narrower than that defined by parts 17A and 24A, the cross-sectional area available to the flow of fluid may be generally the same as or greater than overthe partofthe path defined by 17Aand 24A because of the increased diameter of the radially outer portion of the paths. The narrower part of the path inhibits blockage of the flow path by material entering the outlet 16 but without reducing the rate at which water can pass through the nozzle.

A series of grooves 27 formed in the threaded portion 24 provide passages for water to the flow path at the end of the valve member 23 and the grooves 27 are spirally arranged to cause the water to swirl as it passes to the outlet 16.

Below the portion 26 the valve member is of reduced diameter and is generally cylindrical as at 28. An axial bore 30 extends from one end of the member 23 which lies adjacent the inlet 15 and leads to radial bores 32 having outlets in the outer face of the portion 28.

A resilient sleeve 33 of, for example, rubber, is located about the portion 28 and has a radially outwardly projecting integral flanged portion 29 at its lower end, the sleeve 33 covering the ends of the radial bores 32. The sleeve 33 is retained in position on the portion 28 by metal or plastic washers 34 and 35 which may be inter-connected as at 35'. The washer 34 is seated on or bonded to the portion 29 and engages the shoulder 20A and the washer 35 is located under the portion 29 and is held in position by a circlip 36 located in the groove 20B. A clearance 37 is provided between the lower end of the portion 28 and the washer 35 except when the valve member 23 is in the fully open position.

The portion 29 of the sleeve 33 has its outer edge as an interference fit in the opening 14 to act as a seal between sleeve and the wall of the opening but the valve member 23 is movable axially relative to the sleeve 33.

Afilter element (not shown) may be located against the washer 35 or the circlip 36 to filter the water entering the nozzle.

As shown in the drawing the valve member 23 is shown near its lowermost position in which the restriction to the flow of water through the nozzle is least. In this position material which may have entered the outlet 16 will be flushed out by the flow of water passing to the outlet.

In use for dust suppression purposes the member 23 is moved upwards by rotation of the member until the portion 24 approaches the portion 17 and is at the desired distance therefrom.

As a flow of water the nozzle is initiated the water will enter the bores 30 and 32 but the water will be unable to pass the sleeve 33 until the water pressure can push aside the sleeve 33 to create a flow path towards the grooves 27. Moreover, when the water supply to the nozzle is interrupted water in the bores 30 and 32 is unable to flow out the nozzle and the pipes carrying water to the nozzle should therefore remain full. This means that as soon as a water supply of the minimum predetermined pressure to open the valve member is re-established water will flow immediately from the nozzle. Such predetermined minimum pressure is envisaged as being in the range 5to 10 Ibs persq. inch, and the nozzle should be operable up to pressures of at least 1500 Ibs persq. inch.

To give adequate wear and corrosion resistant properties the bodies of spray nozzles have hitherto been made of chromium steel. In the present case it has been found that adequate properties can be achieved by forming the body 10 from mild steel which is machined and then coated with Wear-Cote (Trade Mark of Wear-Cote International Inc.).

The spray nozzle described is easily unblocked if blockage of the outlet occurs by opening up the flow paths near the outlet. The rate of flow of water is readily controlled and the spray does not suffer loss of water when not in use.

Claims

1. A spray nozzle comprising a body member having an opening extending between a fluid outlet and a fluid inlet, a movable valve member located in the opening and defining with the body member adjacent the outlet a fluid flow path which is generally annular and converges towards the outlet, the valve member being movable to vary the cross-section of said flow path.

2. A spray nozzle according to claim 1 wherein the cross-section of said fluid flow path varies so that the cross-section is wider over a portion of the path nearest to the outlet than over a portion remote from the outlet.

3. A spray nozzle according to claim 1 or 2 wherein said fluid flow path is generally conical, the outlet being located at the apex of the cone.

4. A spray nozzle according to claim 3 wherein the cone is in two contiguous portions having different cone angles, the portion adjacent the outlet having a greater cone angle than the other portion.

5. A spray nozzle according to any one of the preceding claims wherein the valve member is in screw-threaded engagement with the opening in the body member and is movable towards and away from the outlet by relative rotation of the valve and body members to vary the cross-section of said flow paths.

6. A spray nozzle according to claim 5 wherein the screw-threaded portion of the valve member is formed with a duct or ducts extending transverse to the threads whereby the fluid passes to said fluid flow path, the duct or ducts being angled to induce a swirl in the fluid in said path.

7. A spray nozzle according to claim 5 or 6 wherein the valve member has receiving means for a turning tool whereby the valve member is rotated relative to the body member, access to the receiving means being through the fluid outlet.

8. A spray nozzle according to any one of the preceding claims wherein the valve member has a portion, remote from the outlet, formed with a fluid duct one end of which is in communication with the fluid inlet and the other end of which is obstructed by a resilient obturating member, the obturating member preventing flow of fluid from the inlet towards the outlet until the fluid pressure in the duct exceeds a predetermined value.

9. A spray nozzle according to claim 8 wherein the obturating member is in the form of a resilient sleeve located around the ducted portion of the valve member.

10. A spray nozzle according to claim 9 wherein the ducted portion of the valve member is generally cylindrical and the duct includes a longitudinal bore leading to a transversely extending bore or bores opening to the outer surface of said portion, the sleeve being located about the cylindrical portion and over the end or ends of the transverse bore or bores.

11. A spray nozzle according to claim 8,9 or 10 wherein the obturating member engages between the ducted portion of the valve member and the wall of the opening in the body member to seal the valve member against said opening at the inlet end of the body member.

12. A spray nozzle according to any one of claims 8-11 wherein the obturating member is restrained in position on the valve member by retaining means.

13. A spray nozzle comprising a body member having an opening extending between a fluid inlet and a fluid outlet, a valve member located in the opening and formed with duct means communicating at one end with the inlet, and a resilient obturating means obstructing the other end of the duct, the obturating means preventing flow of fluid from the inlet through the duct and towards the outlet until the fluid pressure in the duct exceeds a predetermined value.

14. A spray nozzle according to claim 13 wherein the obturating means is in the form of a resilient sleeve located around a cylindrical portion of the valve member.

15. A spray nozzle according to claim 14 wherein the duct means includes a longitudinal bore leading to a transversely extending bore or bores opening to the outer surface of the cylindrical portion, the sleeve being located over the end or ends of the transverse bore or bores.

16. A spray nozzle substantially as described with reference to the drawing.