The present invention relates generally to the field of high pressure cleaning machines (e.g., pressure washers). More specifically, the invention relates to nozzle assemblies for pressure washers, wherein the nozzle assemblies are configured to reduce the turbulence of a water flowing through the pressure washers.
Powered pressure washers are known to be used to clean dirt, paint, or mold from pavement, brick face, cement, or other surfaces. To achieve such results, these devices generally provide a high pressure water stream (e.g., approximately 1400 psi) at a modest flow rate (e.g., approximately 1.3 to 1.4 gpm). Heavy duty pressure washers may provide streams with even higher pressures (e.g., 3000 to 5000 psi) at possibly greater flow rates (e.g., approximately 3.5 gpm). The high pressure streams of heavy duty pressure washers facilitate more demanding tasks, such as resurfacing or cutting of materials.
In certain applications, a long traveling distance of a high pressure cleaning machine spray beam is a useful feature, such as during second-story window cleaning from the ground or during gutter cleaning from the top of a stationary ladder. In other applications, high beam strength of a pressure washer spray beam is a useful feature, such as for washing off tree sap or bird residue. However, due to limitations of some pressures washers, spraying beams may not be focused, coherent, or steady upon leaving a spray gun. Instead the spraying beams may have a high degree of turbulence and choppiness, causing beam water to scatter, weakening the beam, reducing water density (and momentum) of the beam, increasing the beam surface area and drag on the beam, and shortening the potential traveling distance of the beam.
One embodiment of the invention relates to an assembly for controlling water turbulence through a high pressure cleaning machine. The assembly includes a nozzle body, which has an inlet, an outlet, and a flow path. The nozzle body also includes a plurality of conduits (e.g., tubes) arranged in parallel with each other along the flow path and located between the inlet and the outlet. This plurality of conduits is designed to reduce a turbulence of water flowing through the assembly.
Another embodiment of the invention relates to a pressure washer for cleaning applications. The washer includes a motorized water pump for driving a flow of water, and a spray gun designed to spray the flow of water. The spray gun includes a nozzle body and a turbulence control member designed to reduce a turbulence in the flow of water.
Yet another embodiment of the invention relates to a pressure washer spray gun for cleaning applications, which uses a high-powered stream of water for the cleaning. The spray gun includes a housing with a handle and a water duct attached to the housing, where the duct forms a flow path. Additionally, the spray gun includes a controller (e.g., trigger) for operating a valve attached to the duct and positioned in the flow path, where the controller is designed to release the valve. The spray gun also includes a nozzle body attached to the duct, where the nozzle body includes a turbulence control member.
Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.
The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which:
Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
The pressure washer system 110 includes the motorized water pump 112, wherein the pump is powered by a horizontally-mounted (or vertically) combustion (or electric) engine 140, including a fuel tank 142, a recoil starter 144, a crank case 146, and other engine components. As such, a crank shaft mechanically powers the motorized water pump 112, which may be in the form of a centrifugal pump, rotary pump, peristaltic pump, or other positive displacement or rotodynamic-type pump, and which may include additional gearing to transfer power from the crank shaft to the pump. The motorized water pump 112 drives (e.g., adds work energy to) a water flow, increasing water pressure, flow rate, flow velocity, temperature, or other characteristics of the water flow. In other embodiments, engine 140 includes an automatic starter. In still other embodiments, the pump 112 is powered by an electric motor receiving electricity from an outlet or battery.
Exemplary embodiment pressure washers are designed (i.e., rated) for production of a maximum pressure and flow rate. The maximum pressure rating for the pressure washer system 110 ranges from about 80 psi (e.g., for “garden hose booster washers”) to about 6000 psi (e.g., for very heavy duty pressure washers), with a preferred range from about 100 to 4500 psi. The maximum flow rate ratings for the pressure washer system 110 ranges from about 0.5 to 8 gpm, with a preferred range from about 1 to 6 gpm, and more preferred range from about 2 to 5 gpm (e.g., 2.2 gpm).
Referring to
Still referring to
The inlet 260 and the outlet 262 shown in
A flow of a fluid, such as water, can be characterized as laminar, turbulent, or within a spectrum of transition between laminar and turbulent flow, for example, where a portion of the flow is laminar while another portion is turbulent. One way to quantify the turbulence of a flow is with the Reynolds number, where a higher Reynolds number corresponds to a more turbulent flow. For example, in some pressure washer embodiments employing the turbulence control member 340, an exiting water stream may have a flow turbulence corresponding to a Reynolds number of less than about 4000 (dimensionless), with a preferred Reynolds number of less than about 2300. In other embodiments employing a turbulence control member, the Reynolds number is decreased as a result of the turbulence control member, but still exceeds 4000 upon exit.
The turbulence control member 340 of the nozzle assembly 310 includes several components. Referring to
The turbulence control member may employ a broad range of tubular conduit structures. In some embodiments, a plurality of conduits form an array that is asymmetrical along certain axes. For example, the array may be asymmetric to optimize the efficiency of controlling turbulence for a flow traveling around a curve. In some embodiments, the conduits 360 vary in length and width relative to each other. According to various exemplary embodiments, the number of individual conduits can range from two to 1000, preferably from four to fifty, and more preferably from five to fifteen. According to certain alternative embodiments, the conduits 360 are not cylindrical or circular in cross section, but instead are rectangular, hexagonal, oval, and other geometries. Some embodiments include conduits of different shapes arrayed together in a group. In some embodiments, the cross section of an individual conduit may vary as a function along the length of the conduit, such as a tapering conduit, or an expanding then contracting conduit. In still other embodiments, the conduits 360 are not straight, but instead have a curvature. For example, some conduits may be arranged much like individual strands in a composite rope, braid, or similar structure, where the curvature provides a controlled vorticity to the flow.
The conduit length and width of the conduits 360 are optimized to facilitate a desired Reynolds number in the exit stream for a given pressure washer having a particular maximum pressure and flow rate. A metric for quantifying the particular structure of a conduit is to compare the conduit length to its cross-sectional width. For conduits without circular cross sections, length may be compared to an average cross-sectional width. In some exemplary embodiments, the length of a conduit is greater than the average cross-sectional width; in a preferred embodiment, the length of a conduit is greater than two times the average cross-sectional width; and in a more preferred embodiment, the length of a conduit is greater than ten times the average cross-sectional width. For example, a conduit may have a length of twenty times the average cross-sectional width of the conduit.
The screens 352, 354 may have various configurations depending upon the embodiment. Some embodiments have screens 352, 354 of different sizes and mesh configurations placed in series along the water flow. Certain embodiments have screens 352, 354 positioned before, within, and after a plurality of conduits. Some embodiments have screens 352, 354 that intersect the entire flow path, while other embodiments have screens intersecting only a portion of the entire flow path. In some exemplary embodiments the screens are arranged in a C-shape or cup shape, where the base of the cup (or the back of the C-shape) is positioned in the flow path, and where the sides of the cup (or top and bottom of the C-shape) are positioned along the inside wall of the surrounding nozzle body. Screens 352, 354 may have square holes, circular holes, oval holes, rectangular holes, other shaped holes and holes formed from combinations of such shapes. Some screens may also function as filters.
The turbulence control members (e.g., member 340, member 440, and member 540) may also be utilized with unassisted garden hose spray nozzles (i.e., without an auxiliary pump, typically at pressures below 100 psi). For example, the nozzle assemblies shown in
The terms “coupled,” “connected,” and the like, as used herein, mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.
References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” “front,” “back,” etc.) are merely used to describe the orientation of various elements in the accompanying drawings. The orientation of various elements may differ according to other exemplary embodiments, and such variations are intended to be encompassed by the present disclosure.
The construction and arrangement of the pressure washer, spray gun, and nozzle assembly systems as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. In some embodiments, a turbulence control member may be positioned in a flow path before a water enters a pump (e.g., in addition to or instead of at the nozzle), because a reduced turbulence may increase pump efficiency. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.