US3595482A - Spray devices - Google Patents

Abstract

A spray nozzle is in the form of a chamber 1 having end walls 2 and 3 each with an aperture 4, 5 respectively. The fluid to be sprayed is drawn from a feed tube 6 and is circulated within the chamber 1 by a deflector plate 8. A pressurized fluid, e.g. compressed air, is fed via a pipe 11 through the aperture 4 and through the center of the chamber 1. This pressurized fluid carries with it droplets of the fluid to be sprayed which emerge at a high velocity from the nozzle 12 carried by the aperture 5. A plurality of spray nozzles may be connected in cascade to provide a spray system. Because of the high-velocity spray produced, the device may conveniently be used to cool the inner surface of a housing using a deflector plate 14.

Description

United States Patent [72] Inventor John Alexander Jeflerson-Loveday Rugby, England [21] Appl. No. 800,174 [22] Filed Feb. 18, 1969 [45] Patented July 27, 1971 [73] Assignee The English Electric Company Limited London, England [32] Priority Feb. 19, 1968 [33] Great Britain [31 1 7989/68 [54] SPRAY DEVICES 6 Claims, 6 Drawing Figs.

[52] 0.8. CI 239/403, 239/124, 239/432, 239/434, 239/601 [51] Int. Cl B05b 7/10 [50] Field of Search 239/403, 434.5, 434, 427.3, 432,124, 405

[56] References Cited UNlTED STATES PATENTS 729,516 5/1903 Steilberg 239/432 X 1,785,802 12/1930 Adams 239/434 Primary ExaminerLloyd L. King AttorneysMisegades & Douglas, Keith Misegades and George R. Douglas, Jr.

ABSTRACT: A spray nozzle is in the form of a chamber I having end walls 2 and 3 each with an aperture 4, 5 respectively. The fluid to be sprayed is drawn from a feed tube 6 and is circulated within the chamber 1 by a deflector plate 8. A pressurized fluid, e g. compressed air, is fed via a pipe 11 through the aperture 4 and through the center of the chamber 1. This pressurized fluid carries with it droplets of the fluid to be sprayed which emerge at a high velocity from the nozzle 12 carried by the aperture 5.

A plurality of spray nozzles may be connected in cascade to provide a spray system.

Because of the high-velocity spray produced, the device may conveniently be used to cool the inner surface ofa housing using a deflector plate 14.

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SPRAY DEVICES This invention relates to spray devices.

According to the invention, a spray. device comprises a chamber, means for admitting a first fluid to the chamber for circulation therein, an aperture in the chamber wall at each end of the axis of said circulation, substantially perpendicular to said axis, and means associated with one of said apertures for feeding a second fluid through said one aperture and through the other aperture via the chamber along the axis of circulation, the arrangement being such that particles or droplets of said first fluid are carried through said other aperture by the second fluid.

Preferably, the chamber is of circular cross section, said apertures are carried by end walls therefor, and the first fluidfeeding means comprises a duct which opens into the chamber at a tangent to the latter. The duct may have a deflector mounted therein to facilitate circulation of the first fluid in said chamber.

A plurality of said spray devices may be arranged in series, in which case each successive device after the first has fed thereto any first fluid not utilized by the immediately preceding device.

In order that the invention may be readily understood, a spray device and various modifications thereof constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic sectional elevation of the device,

FIG. 2 is a section on line "-11 of FIG. 1,

FIG. 3 shows a number of spray devices arranged in series,

FIG. 4 is a modification of the spray device of FIG. 1,

FIG. 5 shows a spray device arranged for wall cooling, and

FIG. 6 is a further modification of the spray device of FIG. 1.

Referring to FIGS. 1- and 2 of the drawings, the device comprises a cylindrical chamber 1 of circular cross section having end walls 2 and 3. Each end wall has a central aperture 4, 5 respectively formed therein. A duct 6 opens into the chamber 1 at a tangent to the latter as shown at 7 (see FIG. 2), where it is stepped to a larger diameter. A deflector plate 8 is located within the duct 6 adjacent the opening 7 into the chamber 1. The aperture 4 of end wall 2 is provided with a screw thread for a union 9 carrying a pipe 11, said pipe being connected to a fluid pressure source (not shown) via a control valve (not shown). The aperture 5 of end wall 3 is also provided with a screw thread for a nozzle 12. It will be appreciated that the nozzle 12 may be dispensed with and that the aperture 5 may act as the nozzle for the device.

In operation of the device, a first fluid, e.g. water, is fed through the duct 6 and a proportion of this water, depending upon the positioning of the deflector plate in the duct, is deflected into the chamber 1 and circulates around the latter. If now a second fluid under pressure, e.g. compressed air or steam, is blown through the aperture 4 via the pipe 11 and through the nozzle 12, this air or steam carries with it droplets of the water circulating in the chamber 1, which droplets will emerge from the nozzle in the form of a spray at a velocity determined by the pressure of the compressed air or steam.

Any water not utilized by the spray device feeds through the duct 6 past the deflector plate and may be conveniently fed to a further spray device. Thus, referring to FIG. 3, four spray devices are shown connected in series by the duct 6 and the pipes 11 for the compressed air or steam form branches from a common air or steam main.

Referring to FIG. 4, an alternative form of spray device is shown where the duct 6 is in two parts referenced 6A and 68 respectively and both parts open into the chamber 1 at a tangent and at angularly spaced positions.

It will be appreciated that with such a form of the device no deflector plate 6 is required for water circulation to take place.

A spray device in accordance with the invention may be conveniently used to cool the inner wall surface of a housing as shown in FIG. 5. Thus, referring to the drawing, the spray device is mounted on the outer wall surface of the housing and feeds through a duct 13 in said wall to a deflector 14 mounted on the inner wall surface. To provide an adequate throw" of the spray onto said inner wall surface the spray issuing from the device needs to be at a high velocity and this is conveniently achieved with a device in accordance with the invention by choosing an appropriate pressure for the compressed air or steam fed through the pipe 11.

Where it is desired to provide a spray into a region of high vacuum, spray flow rates from the configurations of spray device described above may be found inadequate. To overcome this a spray device of the form shown in FIG. 6 may be employed, wherein the first aperture 4 has a transverse bar 15 placed across it, the bar conveniently being of triangular cross section such that the flow of air or steam over it is split. The two separated streams thus formed are partially deflected away from the center of the chamber 1, thus increasing their contact with the water circulating therein, improving pick up of droplets of the same, and thereby increasing the spray flow rate. This feature may be advantageously supplemented by a modified nozzle 12A attached to the second aperture 5, this nozzle having, typically, a frustoconical shape which converges away from the chamber 1.

Instead of the transverse bar 15, a cone may be mounted centrally in the aperture 4 with its apex directed away from the chamber, the cone being supported by radial vanes, conveniently three in number, attached to the periphery of the aperture. A further alternative is to provide the member 15 by machining ducts, for example three, in the chamber wall in place of the single aperture 4 heretofore employed, the ducts being placed equidistant around a pitch circle centered on the axis of circulation of the water within the chamber 1, and each being arranged so as to admit a jet of air or steam into the chamber, in a direction divergent from said axis of circulation.

It will be appreciated that where the pressure on the duct 6 is at atmospheric or above, due to the flow of pressure fluid through the pipe 11 and apertures 4 and 5, a partial vacuum will be created in the chamber 1 and thus the level of the first fluid supplying the duct 6, assuming this latter to be in avertical position as shown in FIGS. 1 and 2, may be actually below the level of said chamber. Alternatively, if the device is required to operate in a vacuum a small pressure differential across the nozzle is necessary to cause the first fluid to flow therethrough as there is very little or no assistance from the pressure fluid since this latter cannot then create a sufficient vacuum in the chamber 1. In this case the vacuum surrounding the nozzle will draw the first fluid from the duct 6, and again the supply level in duct 6 could be below the level of said chamber.

A spray device in accordance with the invention need not have any duct, aperture or nozzle less than 0.375-inch diameter and can therefore dispense with fine filters and special pipework. It will also be appreciated that good atomization can be achieved with spray flow rates as low as 1 gal- Ion/minute, there being no need to vary the dimensions of the spray device or nozzle. Since it can operate with a very low pressure acting on the water within the duct 6, gravity feed for said water is quite sufficient, no pump being necessary. The entire feed system for the spray device may be tested without producing any spray by measuring the flow of each fluid in isolation from the other. Because of the high velocity of the spray produced by the spray devices a greater area can be covered per device than with the more conventional types and it is estimated that seven devices in accordance with the invention connected in series would replace approximately 32 conventional nozzles.

With a spray device modified as shown in FIG. 6, it has been found possible when spraying into a region of very high vacuum, say 29" Hg or more, to produce a very fine highvelocity spray having a cone angle of more than This can be achieved by using water as the first fluid, and steam as the second, the steam expanding violently on leaving the nozzle.

Applications for a spray device in accordance with the invention include exhaust cooling for large steam turbines, steam desuperheating, direct contact feed heaters, cleaning the inside of barrels, tanks, etc. It would be possible to use the device as a burner with the water replaced by, e.g. paraffin, and using ajet of air as the pressure fluid. It is also possible to use the device wherever it is necessary to spray a liquid, or even a powder, at high velocity and particularly if the liquid is likely to contain foreign matter where the relatively large ducts and apertures which can be used with the device are unlikely to become blocked.

In view of the foregoing it will be understood that the term first fluid includes liquid, and finely particled powders.

I claim:

1. A spray device comprising:

a body having two end walls between which is defined a substantially cylindrical chamber, each end wall having defined therein a substantially central aperture;

first feeding means connected to the body for tangentially directing a first fluid into the chamber to form therein a vortex aligned on an axis passing through the apertures;

second feeding means connected to the body via one aperture for directing a second fluid into the chamber through the said one aperture so as to flow towards the other aperture, the second fluid passing through the eye of the vortex of first fluid and carrying particles thereof away from the inner surface of the vortex through the other aperture in the form of a spray; and

exhausting means connected to the body for enabling first fluid not carried into the said spray to escape from the chamber.

2. A spray device according to claim 1, wherein the first feeding means and the exhausting means comprise a single fluid duct disposed tangentially with respect to, and communicating with, the said chamber at an intermediate point along the length of the duct.

3. A spray according to claim 2 wherein a deflector is disposed in the said single fluid duct near the said intermediate point for deflecting first fluid into the said vortex.

4. A spray device according to claim 2, wherein the first feeding means comprises a first fluid duct disposed tangcntially with respect to, and communicating with the said chamber at a first point on the circumference thereof, and the exhausting means comprises a second fluid duct disposed tangentially with respect to, and communicating with, the said chamber at a second point on the circumference thereof,

5. A spray device according to claim 1, wherein the said one aperture has disposed therein deflecting means for imparting a radial component of velocity to the second fluid to increase the degree of contact thereof with the said inner surface of the said vortex.

6. A spray device according to claim 5, wherein a convergent nozzle is disposed outside the said chamber adjacent the said other aperture.

Claims (6)

1. A spray device comprising: a body having two end walls between which is defined a substantially cylindrical chamber, each end wall having defined therein a substantially central aperture; first feeding means connected to the body for tangentially directing a first fluid into the chamber to form therein a vortex aligned on an axis passing through the apertures; second feeding means connected to the body via one aperture for directing a second fluid into the chamber through the said one aperture so as to flow towards the other aperture, the second fluid passing through the eye of the vortex of first fluid and carrying particles thereof away from the inner surface of the vortex through the other aperture in the form of a spray; and exhausting means connected to the body for enabling first fluid not carried into the said spray to escape from the chamber.

2. A spray device according to claim 1, wherein the first feeding means and the exhausting means comprise a single fluid duct disposed tangentially with respect to, and communicating with, the said chamber at an intermediate point along the length of the duct.

3. A spray according to claim 2 wherein a deflector is disposed in the said single fluid duct near the said intermediate point for deflEcting first fluid into the said vortex.

4. A spray device according to claim 2, wherein the first feeding means comprises a first fluid duct disposed tangentially with respect to, and communicating with the said chamber at a first point on the circumference thereof, and the exhausting means comprises a second fluid duct disposed tangentially with respect to, and communicating with, the said chamber at a second point on the circumference thereof.

5. A spray device according to claim 1, wherein the said one aperture has disposed therein deflecting means for imparting a radial component of velocity to the second fluid to increase the degree of contact thereof with the said inner surface of the said vortex.

6. A spray device according to claim 5, wherein a convergent nozzle is disposed outside the said chamber adjacent the said other aperture.

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