Air Screen Spray Nozzle

Abstract

An adjustable nozzle is provided which cooperates with air ducting to deflect and remove turbulence from a stream of air and convert the same adjustably into an air screen of desired thickness and quality with homogeneous airflow.

Description

This invention relates to an adjustable jet nozzle, mountable over a doorway or window, useful in association with an elongated air duct to supply an air screen or curtain protective of the doorway or window when open to prevent or reduce air communication or flow between air bodies upon opposite sides of the air screen.

In the construction of air screen devices, the source of air supply is generally rectangular ducts through which the air passes, oftimes with some turbulence due to irregularities in temperature, minor obstructions, and dimensional variations in the said metal ducting, as well as some turbulence produced by angular bends in the ducting. The air screen per se, however, needs to be a homogeneous nonturbulent sheet of air of narrow cross-sectional dimensions passed under sufficient velocity and pressure from an emitting nozzle to protectively cover a doorway or window. Such opening may be longer than the screen and the screen must often extend from an upper position to approximately the lower floor positions. Air needs to flow into the screen smoothly without turbulence to form a protective air sheet, notwithstanding sometimes frequency breaking of the integrity of the sheet by passage of persons into or through the protective air screen or sheet and the doorway protected by them.

Such air screen protects air spaces sometimes in widely varying temperature contrast to the outside air which tends to deform the air screen. Sometimes, more important, the air screen may tend to be disrupted by winds or turbulent air conditions existing on one or both sides of the screen.

A useful screen is produced by emitting the air under strong static pressure through a nozzle mounted to extend across a doorway or window to be protected; that is, from side to side. The available static pressure upon the screen may be adjusted by adjusting the outlet opening of the nozzle to the desired dimensions.

Equally important, the inherent turbulence of air flowing to the nozzle from which the air screen is projected must be removed, so that the expelled air may be evenly distributed under constant pressure over the length of the nozzle, removing the turbulence before the air is emitted from the nozzle in a sheet of adjusted thickness.

The present nozzle provides a construction which solves these several problems in allowing redistribution as a screen of axially flowing air passing into the nozzle easily along its length; in removing the turbulence of the air despite angular deflection and baffling toward the nozzle outlet; and in adjustment of the dimensions of the outlet to provide a sheet of adequate pressure and great homogeneity from the static pressure available.

These several objects are provided by the present nozzle construction and others will be inherent in the description of the invention that follows, the invention being fully described with reference to the drawings wherein:

FIG. 1 is a perspective view of the elongated duct as it appears mounted at the top of a window or doorway to provide a protective screen thereover;

FIG. 2 is a bottom view showing the outlet, the baffling vanes and the adjustment means;

FIG. 3 is an end view taken on the line 3--3 of FIG. 1.

FIG. 4 is a drawing in diagrammatic perspective illustrating the details of the nozzle.

In the drawings, the nozzle 10 may be mounted within or be connected axially to ducts through which a supply of air may enter and flow axially from either or both ends, such as in the direction of arrow 12 into a plenum space 14 enclosed by upper 16 and lower 18 walls as well as an outer sidewall 20 and an opposite nozzle wall 22. The nozzle wall 22 combines the air to curved-streamlined airflow as it passes downward from the upper wall 16, such curvature being shown about the area 24. The inner portion of the nozzle wall 22 has a row of vertically mounted parallel vanes 26, each disposed several inches apart, and which serve to remove any eddy currents and constrain the air to blow homogeneously downward as it moves horizontally along the walls 16 and then vertically downward along wall 22, and then out the nozzle outlet 28 as the air curtain.

An inner adjustable body 30 has a vertical nozzle wall 32 which joins a horizontal nozzle wall portion 34 by way of streamlined curvature wall portion 36. The nozzle body 30 is integral with a bottom wall portion 38. The bottom wall portion 18 has a series of elongated slots 40 which slidingly receive the heads 42 of bolts, upon which wingnuts 44 are correspondingly threaded, the bottom of the duct wall 18 being bored to receive the bolts 42 having rounded heads and wingnuts 44 threaded thereon, and thus is capable of adjustably securing the nozzle body 30 in fixed nozzle opening position.

With this construction the inner nozzle body 30 becomes slidably adjustable by movement with the bolts 42 through their slots 40, whereby the vertical nozzle wall 32 may be set an adjusted distance away from the parallel outer wall 22 to define the thickness of an air screen emitted therebetween by way of outlet 28.

The inner nozzle wall 32 further supports a series of vanes 46, positioned to alternate with vanes 26. The air passes outward through outlet 28 following the arrows 48 and between the nozzle walls 32 and 22 have most of the eddy currents baffled out, and the airstream is homogeneous narrow air curtain free of eddy currents, which is projected downward from outlet 28 under static pressure available from the air flowing angularly from the plenum 14 toward the outlet nozzle in the direction of arrows 48.

Moreover, the airflow axially through plenum 14 is also deflected by a series of baffles 50 which intercept the axial flow through the plenum 14, moving the body of air thence angularly toward the nozzle as in the direction of the arrow 52, passing thence in the direction of arrow 48, the turbulence and the eddy currents in the air being further reduced and removed in combing by vanes 26 and 46.

Thus the inner nozzle wall is adjustable by loosening of the wing nuts 44 and sliding the inner nozzle assembly toward or away from the outer wall 22 so that the outlet nozzle of opening 28 is an adjustable dimension for providing the selected thickness of the air screen as it is emitted. While the duct body 10 in which the nozzle can be mounted may continue on as an integral portion of a duct, it may have flanges such as 54 for its ends, corresponding to the width of a window or doorway over which the nozzle is to be mounted, whereby the flanges 54 will fasten to any duct flange for supply of air to the nozzle.

The air in the duct will be provided with means such as a blower (not shown) for moving the air under a sufficient pressure into the nozzle to provide the air screen.

Other modifications will occur to those skilled in the art. For example, the wing nut fastening means, for instance, can have other quick fastening devices substituted.

Claims

What is claimed is:

1. An adjustable nozzle for an air screen comprising a housing enclosing a plenum chamber, an outer wall member directing air from said plenum toward a lower outlet, a faired inner wall member supported parallel to said outer wall member and defining between said wall members a nozzle outlet communicating with said plenum, at least one of said nozzle walls having a series of vertical baffles mounted with said nozzle outlet baffling the air to nonturbulent, streamlined flow outwardly as it passes between said walls, said nozzle outlet being dimensioned between said wall members corresponding to the desired thickness of an air screen to be evolved through said outlet, said wall members having a length selected to provide an air screen of desired longitudinal dimensions to cover a wall opening over which the nozzle and the air screen is to be protectively mounted, and means for adjusting the distance between said nozzle walls to provide an air screen nozzle outlet of selected dimensions.

2. The device as defined in claim 1 wherein both of said walls have a series of baffles mounted within the nozzle outlet baffling the air to nonturbulent streamlined flow outwardly as it is emitted between said walls.

3. The device as defined in claim 1 wherein the baffles in one of said walls is offset in the direction of the length of said nozzle from the baffles of the other wall whereby all baffles are alternately positioned.

4. The device as defined in claim 1 wherein the nozzle comprises an elongated housing having an inner adjustably movable nozzle wall, said housing having a plenum portion and an inner movable wall portion, said inner movable wall portion having a series of baffles extending toward the plenum portion whereby to baffle the flow of air radially toward the nozzle outlet.

5. The device as defined in claim 1 wherein the nozzle comprises an elongated housing having an inner adjustably movable nozzle wall, said housing having a plenum portion and an inner movable wall portion, said inner movable wall portion having a series of baffles extending toward the plenum portion whereby to baffle the flow of air radially toward the nozzle outlet, one of said nozzles walls having a series of baffles mounted within the nozzle outlet baffling the air to nonturbulent, streamlined flow outwardly as it is emitted between said walls.

6. The device as defined in claim 1 wherein the nozzle comprises an elongated housing having an inner adjustably movable nozzle wall, said housing having a plenum portion and an inner movable wall portion having a series of baffles extending toward the plenum portion whereby to baffle the flow of air radially toward the nozzle outlet, both of said nozzle walls having a series of baffles mounted within the nozzle outlet baffling the air to nonturbulent, streamlined flow outwardly as it is emitted between said walls.