Fan nozzle

Abstract

A fan nozzle for cleaning a surface with an abrasive blast media is constructed of a longitudinal body having an axial pathway through which the media is passed under pressure for release from a substantially rectangular cross-sectional outlet to release the media in a substantially flat, wide path. A first transition zone provides a conversion in the axial pathway from the inlet cross-section to the substantially rectangular cross-section of the outlet opening. A second transition or convergence zone first reduces and then expands the cross-section of the axial pathway for providing a Venturii acceleration of the media as it passes through the nozzle. The transition zone and the convergence zone may be coexistent along a portion of the axial pathway.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The subject invention relates generally to nozzles for releasing abrasive media under pressure and is specifically directed to a fan nozzle for releasing the abrasive media in a wide, flat path.[0003]2. Discussion of the Prior Art[0004]Fan nozzles are relatively well known in the industry and are used to release an abrasive media under pressure in a substantially wide, flat path instead of in a circular pattern as with nozzles with round openings. Such nozzles are particularly convenient when the abrasive media is being used to clean a large surface and it is desirable to pass the nozzle over the surface in sweeping motions.[0005]Typically, such nozzles are adapted to be connected to a common source of pressurized abrasive media, which normally is a coupler on the end of a hose of circular cross-section. The circular cross-section of the inlet end of the nozzle is then in communication with a convergence zone wherein th...

AI Technical Summary

Benefits of technology

[0013]The convergence zone may reduce the cross-sectional area of the axial pathway in a plane parallel to the release path. Alternatively, the convergence zone may reduce the cross-sectional area in a plane perpendicular to the release path. In addition, where desired, the convergence zone may reduce the cross-sectional area of the axial pathway in planes both parallel to the release path and perpendicular to the release path.

[0015]By providing the transition zone in accordance with the subject invention the media flow is converted from a flow of circular cross-section to a flow of rectangular cross-section over a longitudinal path. This provides a smooth transition and minimizes both turbulence and wear. In addition, by providing a smooth transition, the abrasive particles are more evenly distributed throughout the flow area cross-section whereby the hot spots in the media flow outlet are substantially reduced.

[0016]The transition zone is used in combination with a convergence zone to both convert the cross-sectional pattern of the flow and accelerate the flow to provide improved fan nozzle performance with a desirable wide, flat path with a minimum of hot spots. This permits more even flow of the media and more even cleaning or preparation of the surface being treated.

Problems solved by technology

While such nozzles may be useful for the intended purpose of providing a pressurized blast media in a flat path for cleaning surfaces, they all have a common drawback.

This creates wear points at the transition, as well as turbulence.

In addition, such a configuration creates hotspots in the media flow as the media is released from the nozzle.

This provides for an immediate transition from a circular source to a rectangular nozzle pathway, creating a wear point at the transition, as well as generating turbulence in the flow.

While an improvement over earlier designs, this still does not overcome the hot spots typically present in a fan nozzle.

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