High-pressure cleaning spray nozzle

Abstract: A high-pressure spray nozzle (10) includes a nozzle body (12) with a longitudinal channel (24) formed therein that provides a fluid passageway between an inlet (26) and a mouth zone (20). The passageway has an inner configuration that includes a shoulder (34) with a generally radiused portion that enables increased force and a more even spray distribution for fluid exiting the mouth zone.

Description: The present invention relates generally to spray nozzles, and more particularly, to spray nozzles for high-pressure cleaning applications. Spray nozzles for high-pressure cleaning applications typically direct a flat spray liquid discharge against a surface to be cleaned. The liquid discharge forcefully impinges against the surface in order to remove dirt or other particles thereon. If uniform cleaning is to take place, it is necessary that the liquid discharging spray have a substantially uniform impingement force for a given area. Heretofore, it has been difficult to achieve such uniformity in the force of the discharging spray particles due to turbulence created within the nozzle body at the required velocity of the liquid spray. Another aim in the development of such cleaning apparatus is to achieve a high cleaning effect with as little as possible consumption of cleaning fluid. US 4 223 841 discloses a nozzle, for washing car headlights, having a passage that converges towards the outlet end. The outlet end has a particular shape to give the washing liquid spray the desired spray pattern. The passage may also contain a spinning member to spin the outgoing fluid. The general aim of the present invention is to provide a new and improved nozzle construction for use in high-pressure cleaning applications. It is a further object of the present invention to provide a high-pressure spray nozzle with improved force of impingement of the discharging spray. A more particular object of the invention is to achieve the foregoing through the provision of a nozzle construction having a particular inner surface configuration which reduces turbulence as the fluid is discharged from the nozzle. It is an additional object of the invention to provide improved lateral spray stability in a high-pressure spray nozzle. These and other objects and advantages are provided with a high-pressure spray nozzle having a particular structural arrangement which offers greater performance than known systems. According to the invention we provide a high pressure liquid spray nozzle comprising: an elongated nozzle body having an upstream inlet end into which a liquid may be directed and an outlet end, a longitudinal liquid flow passageway in said nozzle body extending between said inlet and outlet ends, said longitudinal passageway including a first cylindrical passageway section having a first diameter, a second cylindrical approach passageway section that extends a predetermined length at a location downstream of said first passageway section and has a diameter less than the diameter of said first passageway section, said liquid flow passageway having a discharge orifice in the outlet end of said body sized less than the diameter of said second approach passageway section for imparting a predetermined spray pattern to liquid discharging from said discharge orifice, and a curved wall defining a curved transition between said second approach passageway section and said discharge orifice, and a shoulder defining a curved transition between said first passageway section and said second approach passageway section, and said second approach passageway section having a longitudinal length between one and one-half and twice the diameter of said second approach passageway section such that liquid directed through said longitudinal passageway continuously converges from said first passageway section to said discharge orifice with said curved transitions, enabling high pressure liquid to be directed through the nozzle without substantial turbulence and to discharge from the discharge orifice in a high pressure spray pattern with a substantially uniform impact force on a surface onto which it is directed. The approach has a reduced diameter and an increased length with respect to known nozzle designs. This configuration enables a greater force of impingement and a more even spray distribution for fluid discharged from the nozzle. Other objects and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. Figure 1 is a partially cut-away view of a high-pressure cleaning nozzle which incorporates the features of the present invention; Figure 2 is a cross-sectional view taken axially through the nozzle shown in Figure 1; Figure 3 is an end view of the nozzle shown in Figure 2; and Figure 4 is a cross-sectional view taken axially through a high-pressure cleaning nozzle according to another embodiment of the present invention. Generally, the present invention relates to a nozzle construction that provides improved impact spray distribution. The invention is intended for use in various high-pressure cleaning applications where a fluidized spray is to be impinged on a surface to be cleaned. Typically, the fluidized spray is water or other suitable cleaning solutions or fluids. Figs. 1 and 2 illustrate a high pressure spray nozzle 10 embodying the present invention. The nozzle 10 is adapted for use in high-pressure cleaning apparatus for ejecting a high-pressure fan-shaped water jet toward a surface to be cleaned. The spray nozzle comprises a nozzle body 12 preferably constructed in one piece of metal or other suitable material. The nozzle body 12 includes an upstream end 14, which may be connected to a supply conduit 16 with the use of threads such as threads 18. A nozzle mouth zone 20 is located at the downstream end of the nozzle body. In the illustrated embodiment, the nozzle body 12 is substantially symmetrical in form about a longitudinal axis 22. A channel or fluid passageway 24 is disposed through the nozzle body 12 and is formed as a longitudinally extending bore concentric to the nozzle body about the axis 22. The diameter of the channel 24 generally decreases toward the nozzle mouth zone 20 to define various channel sections. A conical entry zone 26 is located at the upstream entry zone of the nozzle body 12. The entry zone 26 leads to a first cylindrical section 28. A cylindrical second conical zone 30 couples the first cylindrical section 28 with a second cylindrical section 32 of smaller diameter than the upstream or first cylindrical section 28. In accordance with one aspect of the invention, the inner channel configuration includes a radiused transition from the increased cylindrical sections to an approach section to provide greater performance characteristics. In the described embodiment, a curved throat section 34 couples the second cylindrical section 32 with an approach section 36. The approach section or zone 36, in turn, terminates at the nozzle mouth zone 20. The throat section 34 comprises a rounded or radiused shoulder which gradually narrows towards the approach section 36 and in so doing presents a smooth transition surface configuration between the second cylindrical section 32 and the approach section 36. The approach section 36 provides a generally cylindrical zone with a selected diameter A which defines a wall that extends a length L as shown in Fig. 2. For effecting reduced turbulent flow within the nozzle, the shoulder 34 preferably intersects the approach zone wall at a transition that is tangent to the radius of the shoulder 34 such as a transition point T shown in Fig. 2. This provides a smoothed transition fluid path and reduces turbulent flow within the channel. In the described embodiment, the ratio of the diameter A of the approach section 36 compared to the radius of the shoulder 34 is selected to be from between about .23 to .25. In accordance with one advantage of the invention, the ratio of the approach diameter with respect to the approach length is chosen to provide increased fluid velocity. That is, the approach zone has a reduced diameter A that is utilized in conjunction with an increased approach zone length L as compared to known designs. For example, the channel section length L is chosen to be between approximately one and one-half to twice the diameter A of the approach zone. In the illustrated embodiment, the ratio of the approach length L is twice the approach diameter. The slightly reduced or descaled diameter A as compared to the approach length L provides an increased fluid velocity. This structure increases the fluid velocity and also stabilizes the resulting spray. For an exemplary spray nozzle having a 15° spray angle and a spray capacity of 1.51 litres (4 gallons) at 275.8 kPa (40 p.s.i.), an approach zone with a 1.6 mm (.063 inches) diameter may be employed rather than conventional spray nozzles that employ an approach diameter of 1,93 mm (.076 inches). The distal end of the approach zone 36 includes an approach orifice 38 which forms a portion of a circular arc. The angle α of the approach orifice 38 with respect to the central axis 22 is preferably between 40 and 48 degrees. The ratio of the approach diameter A with respect to the approach orifice radius 38 is chosen to be about 1.5 for the exemplary spray nozzle described above. The nozzle mouth zone 20 is shown in detail in Figs. 2 and 3. The mouth zone 20 is formed by a pair of ribs 40, 42 disposed in spaced parallel relation to one another and disposed at the distal end of the nozzle body 12. A groove 44 is disposed transversely through the nozzle body 12 and is arranged at a right angle with respect to the longitudinal central axis 22. The groove has rounded side walls 46, 48 which in each case follow a portion of a circular arc. An outwardly opening groove-type depression 50 is disposed centrally within the groove 44. The depression 50 which has a base 52 (see Fig. 3) rounded at its ends and defines a plane-constructed groove walls 54, 56. The groove walls 54, 56 are arranged lying opposite one another in spaced parallel relation. The depression 50 intersects the longitudinally extending channel 24 in the zone of the rounded approach orifice wall 38. This arrangement forms a passage 58 bounded by an edge 60 (see Fig. 3). The edge 60 is continuously curved and in plan view resembles an ellipse. It is defined by the section of a semicylindrical base 52 of the depression 50 with the curved wall 38 of the approach orifice. In one preferred implementation of the invention, the nozzle is fabricated as a unitary piece from hardened stainless steel. Alternatively, the nozzle may be fabricated as two or more pieces that are designed to be mated or press-fit together such as the embodiment shown in Fig. 4. As shown there, a high-pressure spray nozzle 100 includes a nozzle body 112 formed with a longitudinally extending bore concentric to a central axis 122 to present a channel 124. In this embodiment, the channel 124 is formed with first cylindrical section 128 and a second cylindrical section 132 which substantially extends the from a conical zone 130 to the distal end of the nozzle body 112. The cylindrical section 130 forms a cylindrical opening sized to receive an annular insert 133. The inner surface configuration of the insert 133 includes a radiused shoulder 134, an approach section 136, as well as an approach orifice 138 and other components of the nozzle mouth zone 120 as described above in connection with Figs. 1-3. The size, dimensions, and relative placement of the shoulder 134 and approach section 136 are also the same as described above in connection with Figs. 1-3. In the illustrated embodiment, the insert 133 may be held in place within the opening 130 with the use of a flange 139 disposed at the end of the nozzle body 112. By way of example, the insert may be fabricated of tungsten carbide or a suitable ceramic material. This has particular use when the nozzle is intended to spray abrasive liquids or the like. For effecting coupling of the spray nozzle with the supply conduit, the inlet end is coupled with a conventional female coupling 62 disposed at the end of the supply conduit 16. Alternatively, a quick disconnect configuration may be readily utilized as will be understood by those skilled in the art. In operation, fluid is directed through the supply conduit 16 and toward the upstream end 14 in the direction denoted by the arrow in Fig. 1. Inasmuch as the approach diameter is reduced, the fluid velocity through the nozzle is increased. The increased length of the approach stabilizes the spray. In addition, the radiused shoulder 34 and transition with the approach zone reduces turbulence as the fluid enters the approach zone 36. The resulting spray pattern is a relatively flat fan spray pattern. In the case of water consumption and water pressure remaining constant, the jet force is increased by one-half with respect to conventional flat-jet nozzles. The resulting cleaning effect is substantially improved by 130 to 200 percent or more in comparison with conventional nozzles over the range of flow rates and spray angles typically utilized in high-pressure washing or cleaning applications. For providing added stabilization to the liquid passing through the fluid passageway 24, a guide vane or flow stabilizer (not shown) may be utilized in conjunction with the invention as will be understood by one skilled in the art to which this invention pertains. Typically, such a flow stabilizer is provided as a piece of sheet metal formed in the shape of a "Figure 8" or a cross when viewed from the upstream end of the nozzle. The stabilizer may be located within the cylindrical section 28 and substantially extend the length thereof in abutment against the conical zone 30. Various advantages in the resulting spray pattern are achieved with the invention. For example, where prior spray nozzles may provide a relatively uneven spray pattern with the tendency for streaking or the like to be observed on the cleaning surface, the present invention provides a consistent spray pattern to the surface. That is, the impact force of impingement applied to the surface is flattened out across the entire surface due to the increased approach length for a given flow. The reduced approach diameter for a given flow also provides increased velocity of the fluid for a particular flow rate utilized. Accordingly, a high pressure spray nozzle meeting the aforestated objectives has been described. While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments hereof have been shown in the drawings and have been described in more detail. It should be understood, however, that there is not an intention to limit the invention to the specific forms disclosed.

Claims: A high pressure liquid spray nozzle comprising: an elongated nozzle body (12) having an upstream inlet end into which a liquid may be directed and an outlet end, a longitudinal liquid flow passageway (24) in said nozzle body (12) extending between said inlet and outlet ends, said longitudinal passageway (24) including a first cylindrical passageway section (32) having a first diameter (A), a second cylindrical approach passageway section (36) that extends a predetermined length (L) at a location downstream of said first passageway section (32) and has a diameter less than the diameter (A) of said first passageway section (32), said liquid flow passageway (24) having a discharge orifice in the outlet end of said body (12) sized less than the diameter of said second approach passageway section (36) for imparting a predetermined spray pattern to liquid discharging from said discharge orifice, and a curved wall (38) defining a curved transition between said second approach passageway section (36) and said discharge orifice, characterised by a shoulder (34) defining a curved transition between said first passageway section (32) and said second approach passageway section (36), and said second approach passageway section (36) having a longitudinal length (L) between one and one-half and twice the diameter (A) of said second approach passageway section (36) such that liquid directed through said longitudinal passageway (24) converges from said first passageway section (32) to said discharge orifice with said curved transitions (34, 36) enabling high pressure liquid to be directed through the nozzle without substantial turbulence and to discharge from the discharge orifice in a high pressure spray pattern with a substantially uniform impact force on a surface onto which it is directed. The spray nozzle of claim 1 in which said shoulder (34) defines a radius that intersects the second cylindrical approach passageway section at a point of tangency. The spray nozzle of claim 2 in which the ratio of the diameter of the second approach passageway section (36) with the radius of the said shoulder (34) is between .23 to .25. The spray nozzle of claim 1 in which said longitudinal passageway (24) includes a third cylindrical passageway section (28) disposed upstream of the first passageway section (32) and having a diameter greater than said first passageway section (32) for providing fluid communication between said inlet end and said first passageway section (32). The spray nozzle of claim 1 in which said nozzle body has a one-piece construction. The spray nozzle of claim 1 in which said longitudinal passageway (24) is defined in part in said nozzle body and in part by an insert (133) mounted within said nozzle body.

Inventors: ADAMS ROBERT J, ADAMS, ROBERT J.
Applicants: SPRAYING SYSTEMS CO, SPRAYING SYSTEMS CO.
Application year: 1998
Main classification: B05B1
IPC codes: B05B1