DUST REMOVAL APPARATUS

Abstract

A system includes a dust removal head having an air input assembly, a vacuum output assembly, a high pressure zone and a low pressure zone. The air input assembly is configured for connection to a pressurized air source. The vacuum output assembly is configured for connection to a vacuum machine. The high pressure zone is in fluid communication with the air input assembly. The low pressure zone surrounds the high pressure zone, is in fluid communication with the high pressure zone, and is in fluid communication with the vacuum output assembly. A method of removing dust from a surface using a machine comprises directing pressurized air toward the surface to dislodge the dust from the surface and entrain the dust in a moving air stream within a high pressure zone shroud, conveying the dust-entrained air flow to a low pressure zone container and removing it using a vacuum.

Claims

1. A system comprising: a dust removal head comprising: an air input assembly configured for connection to a pressurized air source; a vacuum output assembly configured for connection to a vacuum machine; a high pressure zone in fluid communication with the air input assembly; and a low pressure zone: surrounding the high pressure zone; in fluid communication with the high pressure zone; and in fluid communication with the a vacuum output assembly.

2. The system of claim 1 comprising the pressurized air source.

3. The system of claim 1 comprising the vacuum machine.

4. The system of claim 1, wherein the high pressure zone comprises a spinning arm assembly that is configured to receive pressurized air from the air input assembly.

5. The system of claim 4, wherein the spinning arm assembly comprises a substantially longitudinal conduit for the pressurized air.

6. The system of claim 5 comprising a nozzle that is oriented at an acute angle relative to a direction that is orthogonal to the substantially longitudinal conduit.

7. The system of claim 6, wherein the acute angle is between about 10 degrees and about 20 degrees.

8. The system of claim 5 wherein the spinning arm assembly comprises an arm having an airfoil shape.

9. The system of claim 4, wherein the high pressure zone is defined by a first shroud covering the spinning arm assembly.

10. The system of claim 9, wherein the low pressure zone comprises a second shroud surrounding the first shroud.

11. The system of claim 10, wherein the second shroud extends closer to a surface from which dust is to be removed than does the spinning arm assembly.

12. The system of claim 10, wherein the second shroud: extends closer to a surface from which dust is to be removed than does the first shroud; and comprises a plurality of apertures between an edge of the first shroud and an edge of the second shroud.

13. The system of claim 10, wherein the low pressure zone comprises a third shroud surrounding the second shroud.

14. The system of claim 1, wherein the dust removal head has a forward motion direction defining a leading edge and a trailing edge, and wherein the low pressure zone has a greater volume proximate the trailing edge than proximate the leading edge.

15. The system of claim 1, wherein the low pressure zone has a greater volume proximate the vacuum output assembly than distal from the vacuum output assembly.

16. The system of claim 1, wherein the dust removal head has a forward motion direction defining a leading edge and a trailing edge, the system comprising a scraper positioned forward of the leading edge.

17. A method of removing dust from a surface using a machine, the method comprising: directing pressurized air toward the surface to dislodge the dust from the surface and entrain the dust in a moving air stream within a high pressure zone shroud, thereby producing a dust-entrained air flow; conveying the dust-entrained air flow to a low pressure zone container; and removing the dust-entrained air flow from the low pressure zone container using a vacuum.

18. The method of claim 17, wherein directing pressurized air toward the surface comprises blowing the pressurized air from opposed ends of a rotating arm assembly.

19. The method of claim 18, wherein conveying the dust-entrained air flow to the low pressure zone container comprises moving the dust-entrained air flow between the high pressure zone shroud and the surface.

20. The method of claim 18, wherein conveying the dust-entrained air flow to the low pressure zone container comprises moving the dust-entrained air flow through a plurality of apertures of the to the low pressure zone container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The disclosed subject matter will be further explained with reference to the attached figures, wherein like structure or system elements are referred to by like reference numerals throughout the several views. All descriptions are applicable to like and analogous structures throughout the several embodiments, unless otherwise specified.

[0010] FIG. 1 is a perspective view of an exemplary dust removal system of the current disclosure.

[0011] FIG. 2A is a perspective view of an exemplary dust removal head configured to be used in the system.

[0012] FIG. 2B is similar to FIG. 2A but shows an optional scraper accessory.

[0013] FIG. 2C is a rear perspective view of the dust removal head disconnected from an air compressor supply hose and from a vacuum hose.

[0014] FIG. 3 is a lower perspective view of a rotary union.

[0015] FIG. 4 is a side perspective view of a rotary union connected to a rotating output arm and clamp.

[0016] FIG. 5 is a side perspective view of the assembly of FIG. 4 attached to an exemplary high pressure zone shroud.

[0017] FIG. 6A is a side perspective view of the assembly of FIG. 5 attached to an exemplary low pressure zone inner shroud.

[0018] FIG. 6B is a side perspective view of a second exemplary embodiment of a low pressure zone inner shroud.

[0019] FIG. 6C is a side perspective view of a third exemplary embodiment of a low pressure zone inner shroud.

[0020] FIG. 7A is a side view of an exemplary low pressure zone outer shroud.

[0021] FIG. 7B is a top perspective view of the exemplary low pressure zone outer shroud.

[0022] FIG. 7C is a top view of the exemplary low pressure zone outer shroud.

[0023] FIG. 8 is a perspective view of the assembly of FIG. 6 positioned within a low-pressure outer shroud of FIGS. 7A-7C.

[0024] FIG. 9 is a perspective view of two exemplary side wall guards.

[0025] FIG. 10A is an exploded view of components of a swivel port assembly.

[0026] FIG. 10B is a perspective view of an exemplary assembled swivel port assembly, positioned for attachment to a weldment of the dust removal head.

[0027] FIG. 11 is an exploded view of components of an air source input assembly.

[0028] FIG. 12 is a cross-sectional view through line 12-12 of FIG. 2A.

[0029] FIG. 13 is a bottom view of a first exemplary dust removal head.

[0030] FIG. 14 is a bottom view of a second exemplary dust removal head.

[0031] FIG. 15A is an end perspective view of a first exemplary spinning arm assembly.

[0032] FIG. 15B is an end perspective view of a second exemplary spinning arm assembly.

[0033] While the above-identified figures set forth one or more embodiments of the disclosed subject matter, other embodiments are also contemplated, as noted in the disclosure. In all cases, this disclosure presents the disclosed subject matter by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that fall within the scope of the principles of this disclosure.

[0034] The figures may not be drawn to scale. In particular, some features may be enlarged relative to other features for clarity. Moreover, where terms such as above, below, over, under, top, bottom, side, right, left, vertical, horizontal, etc., are used, it is to be understood that they are used only for ease of understanding the description. It is contemplated that structures may be oriented otherwise.

[0035] The terminology used herein is for the purpose of describing embodiments, and the terminology is not intended to be limiting. Unless indicated otherwise, ordinal numbers (e.g., first, second, third, etc.) are used to distinguish or identify different elements or steps in a group of elements or steps and do not supply a serial or numerical limitation on the elements or steps of the embodiments thereof. For example, first, second, and third elements or steps need not necessarily appear in that order, and the embodiments thereof need not necessarily be limited to three elements or steps. Unless indicated otherwise, any labels such as left, right, front, back, top, bottom, forward, reverse, clockwise, counter clockwise, up, down, or other similar terms such as upper, lower, aft, fore, vertical, horizontal, proximal, distal, intermediate and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions. The singular forms of a, an, and the include plural references unless the context clearly dictates otherwise.

DETAILED DESCRIPTION

[0036] FIG. 1 is a perspective view of an exemplary dust removal system 100 having apparatus 10. FIG. 2A is a perspective view of an exemplary dust removal head 12 configured to be used in the system 100. FIG. 2B is similar to FIG. 2A but shows an optional scraper accessory 94. FIG. 2C is a rear perspective view of the dust removal head 12 disconnected from an air compressor supply hose 20 and from a vacuum wand 14.

[0037] In an exemplary embodiment, apparatus 10 has a dust removal head 12 attached to a vacuum wand 14 to provide for ease in maneuvering the apparatus 10 across a surface 16 (typically a floor) from which dust is to be removed. While the term dust is used often in this description, it is to be understood that it encompasses all manner of particulate material, including dirt, debris, paint and coating chips, and abrasive waste materials, for example. In an exemplary embodiment, an air compressor 24 connected to an air hose 20 supplies high pressure air to apparatus 10 at air coupler 22. An air valve can be used to control flow between the air compressor and air hose 20. Commercially available air compressors are well known and readily available at most building construction or renovation work sites.

[0038] To remove dust laden air from head 12, vacuum output assembly 28 fluidly connects vacuum port 62 of the head 12 with a vacuum 26. In an exemplary method of use, vacuum output assembly 28 is attached, such as via vacuum wand 14, to a long flexible hose 32 of vacuum 26. In an exemplary embodiment, the air coupler 22 is attached to a long flexible hose 20 of air compressor 24. Thus, these hoses 20, 32 allow apparatus 10 to be moved across the floor surface 16 without necessarily requiring an operator to also move the attached vacuum 26 or air compressor 24. In an exemplary embodiment, head 12 is mounted on moveable ground engaging elements 30 such as wheels, casters, rollers or the like. A head clearance gap dimension is provided above floor surface 16 that is high enough to permit unimpeded motion of dust removal head 12 over the floor surface 16 but is low enough to ensure that air and dust do not escape from head 12 other than by removal through the vacuum output assembly 28. In an exemplary embodiment, apparatus 10 includes a handle 72 positioned on dust removal head 12 to also serve as a protection bar for a top of the head 12.

[0039] In an exemplary system 100, vacuum 26 has a manufacturer rating of 258 cubic feet per minute (7.31 cubic meter/minute) though actual measurements may be closer to 215 cubic feet per minute (6.09 cubic meter/minute). At the end of an extended length of vacuum hose 32, the vacuum performance at vacuum output assembly 28 may be closer to about 133 cubic feet per minute (3.77 cubic meter/minute). For example, vacuum hose 32 may be about 56 feet long (17.1 m).

[0040] FIG. 2B shows an exemplary dust removal head with an optional surface scraper attachment 94, which passes over the floor surface 16 in advance of the leading edge 66 of the dust removal head 12. Scraper 94 agitates, scrapes and loosens material from the floor surface 16 and is especially suitable for use during installation of an epoxy paint chip floor coating. The scraper assists in leveling high peaks of broadcasted material before the dust removal head 12 removes loose materials. In an exemplary embodiment, scraper 94 is attached to a top surface of high pressure shroud 18 by floating arms 96.

[0041] Referring to FIGS. 3-5, in an exemplary embodiment, rotary union 40 is clamped to a base 44 that in turn is fastened to a high-pressure shroud 18. In an exemplary embodiment, high pressure air is introduced to a high-pressure shroud 18 to dislodge dust from surface 16. Dust-laden air is then removed from the head 12 by the vacuum 26, thereby removing the dislodged dust while preventing its release into the surrounding environment.

[0042] FIG. 3 is a bottom perspective view of an exemplary rotary union 40. A rotary union 40 is also known as a rotary joint or a swivel joint and is a mechanical device used to transfer fluid (such as water, oil, air, hydraulic fluid or coolant) from a stationary supply source to a rotating piece of machinery or equipment. It allows for continuous fluid flow between the stationary and rotating parts without leakage or interruption, even as the rotating part spins. In an exemplary embodiment, air input assembly 34 introduces high pressure air from the compressor 24 into inlet 41 of stationary portion 43. Rotating shaft 46 is disposed within the rotary union 40 and includes an air outlet port 50.

[0043] Two specific embodiments of such a spinning arm assembly 47 are described, and in some cases they will be differentiated by referring to the first embodiment with reference number 47a (see FIG. 15A) and the second embodiment with reference to number 47b (see FIG. 15B). However, in many aspects, the spinning arm assemblies are similar; descriptions of assembly 47, 47a or 47b apply to all embodiments unless otherwise specified. This convention also applies to other similarly numbered elements.

[0044] As shown in FIGS. 3 and 4, a spinning arm assembly 47 is connected to air outlet port 50 of rotating shaft 46. In an exemplary embodiment, two hollow tubes 48 are attached to a tee connector 49, which receives and splits the air flow from port 50 (see FIGS. 16A-16C). Opposed ends of the hollow tubes 48 are connected to output nozzles 52 via directional couplings that cause the air outlets 54 to be directed downward. While two hollow tubes 48 are described and illustrated, it is to be understood that more or fewer such rotating tube arms can be used in this apparatus. Referring to FIGS. 15A and 15B, in an exemplary embodiment, each output nozzle 52 has a drilled orifice 54, wherein a bore of the orifice is inclined sideways (in a plane tangent to the spin direction 56) at a small acute angle (such as between about 5 radial degrees and about 25 radial degrees) relative to a vertical direction (such as parallel with vertical walls of the shrouds 18, 36, 38). Thus, high pressure air exiting the orifice 54 and impacting against the floor surface 16 will cause the hollow tubes 48 and connected rotating shaft 46 to spin in direction 56. A particularly suitable range is about 10 radial degrees to about 20 radial degrees.

[0045] FIG. 15B is an end perspective view of a second exemplary embodiment of spinning arm assembly 47b. In an exemplary embodiment, each of the hollow tubes 48b is configured as an air foil rather than as a more common cylinder. The air foil shape provides lift to the air, dust and or any loose material within the high pressure shroud 18, thus enhancing removal of those materials. It is contemplated that many shapes of components can also be used, other than those specifically illustrated.

[0046] FIG. 6B is a perspective view of a second exemplary embodiment of an inner low pressure shroud 38b, having a ring guard 82 disposed on its lower rim. In an exemplary embodiment, guard 82 is a continuous ring having a diameter of at least about inch (6.35 mm), and formed of a solid yet resilient material such as plastic. The guard 82 is preferably rigid to thereby protect the shroud 38 in case of collision with inconsistently high portions of the floor surface 16. Guard 82 can be mounted permanently to shroud 38 or can be semi permanently mounted thereto, for removal and replacement in case of damage.

[0047] FIG. 6C is perspective view of a third exemplary embodiment of an inner low pressure shroud 38c, having apertures 98 therethrough. In an exemplary embodiment, the plurality of apertures 98 are evenly spaced about a circumference of the shroud 38c. Each aperture 98 is sized to permit passage therethrough of larger pieces of material such as rocks, aggregates, or paint chips, for example including those materials that are too large to easily pass between the bottom of the inner low pressure shroud 38 and the floor surface 16. These apertures 98 are positioned, in an exemplary embodiment, below a vertical level of the bottom surface of the high pressure shroud 18 (see FIG. 12).

[0048] Exemplary dimensions of some components of apparatus 10 in system 100 are given here, though it is to be understood that other sizes, capacities and proportions of components can also be used. As shown in FIGS. 4 and 16A, for example, a length of the rotating arm assembly 47 can be about 11 inches (27.9 cm). As shown in FIGS. 6A-6C, the inner low pressure shroud 38 can have a diameter of about 12 inches (30.5 cm), a height at its lower end of about 2.1 inch (5.4 cm), and a height at its higher or taller end of 3.9 inch (9.9 cm), for example. As shown in FIGS. 7A-7C, the larger surrounding outer low pressure shroud 36 has a diameter of about 13.5 inch (34.3 cm), a height at its short end of about 2.0 inch (5.1 cm), and a height at its tall end of about 4.0 inch (10.2 cm). An exemplary port 62 and leg 36 has a diameter of about 1.75 inch (4.4 cm). The air from ports 62 travels into cylindrical inlets of splitter pipe 76 that are slightly larger, at about 2.0 inch (5.1 cm). While certain configurations and dimensions of the illustrated apparatus 10 are provided for completeness and clarity, it is contemplated that other shapes can also be used, as well as other arrangements of components. For example, while dust removal head 12 is illustrated with a substantially circular shape, other housing shapes can also be used, such as rectangular shapes that are quite common with dust removal and vacuum devices.

[0049] FIGS. 7A through 7C show side, perspective, and top views, respectively, of an exemplary outer low-pressure shroud 36. FIG. 8 shows the assembly of FIG. 6 placed within the outer low-pressure shroud 36. In an exemplary embodiment, each of the low-pressure shrouds 36, 38 has a shorter wall height at a leading edge 66 and an inclined top rim 42 that terminates in a higher wall height at a trailing edge 68, relative to a forward motion direction 70, as labeled in FIG. 1. A relatively low-pressure zone 60 is disposed in the space between the inner shroud 38 and the outer shroud 36, which is maintained by a plurality of circumferentially positioned spacers 37. The low-pressure zone 60 is capped by a low-pressure zone cover 64, as shown in FIGS. 2A-2C and 12. The angled cover 64 over correspondingly tapered circumferential walls allows for a larger volume of air toward the trailing edge 68 of the low-pressure zone 60. As the volume of space within low pressure zone 60 increases from the leading edge 66 toward the trailing edge 68, the vacuum pressure is more evenly distributed around the low-pressure zone 60. This configuration assists in evenly moving air out of the vacuum ports 62.

[0050] As shown in FIGS. 2A-2C, 7C, 8 and 10A and 10B, air laden with dust is transported out of the dust removal head 12 through vacuum ports 62, which channel through legs 63 and are fluidly connected to the vacuum 26 via vacuum output assembly 28. In an exemplary embodiment as shown in FIGS. 7C, 13 and 14, brackets 92 are configured and positioned to funnel air flow 102 from the low-pressure zone 60 effectively into the vacuum ports 62.

[0051] FIGS. 10A and 10B are exploded and assembled views, respectively, of an exemplary vacuum output assembly 28. In an exemplary embodiment, a splitter pipe 76 is rotatably connected to swivel bracket 78 with bushings 80 placed therebetween to allow for smooth rotation motion of the splitter pipe 76 relative to the swivel brackets 78.

[0052] FIG. 11 is an exploded view of components of air input assembly 34, which communicates air from the compressor 24, through air hose 20, and into inlet 41 of rotary union 40. In an exemplary embodiment, the air input assembly 34 includes quick connector 22, articulating connector 84, air tube 86, air water filter 88 and right-angle rotary union connector 90.

[0053] As shown in a comparison of FIGS. 2B and 2C, the articulating connector 84 of the air input assembly 34 and the splitter pipe 76 and swivel bracket 78 of vacuum output assembly 28 allow the air input and air output assemblies of apparatus 10 to pivot up and down with the motion of vacuum wand 14 and the attached air hose 20. This permits ease of manipulation, while the dust removal head 12 remains in consistent contact with the floor surface 16.

[0054] Referring to FIGS. 1-2C, 9 and 10B, curved side wall guards 74 can be affixed to an outer surface of the outer shroud 36 to prevent damage to the dust removal head 12 from collisions with walls or other structures. In an exemplary embodiment, each of the guards 74 is formed of a resilient and durable plastic material to prevent denting or other impact damage to the shroud 36. Side wall guards 74 also effectively protect walls of a building or other contacted objects from damage by collision with the apparatus 10.

[0055] FIG. 12 is a cross-sectional view of the dust removal head 12, taken through line 12 12 of FIG. 2A. FIG. 13 is a bottom view of a first exemplary embodiment of the dust removal head 12a. In an exemplary embodiment, inner low-pressure shroud 38 surrounds high pressure shroud and separates a high air pressure zone 58 within the inner shroud 38 from a low air pressure zone 60 between the inner low-pressure shroud 38 and the outer low-pressure shroud 36. High pressure air from the attached air compressor is introduced through air hose 20 to rotary union 40 through air input coupler 22 (see FIGS. 2A-2C).

[0056] As shown in FIGS. 1 and 12, inner shroud 38 and outer shroud 36 are capped at a common top end by low pressure zone cover 64. However, as visible in FIG. 12, inner shroud 38 is not quite as tall in a vertical dimension as the outer shroud 36. Thus, air in the central high-pressure zone 58, once laden with dust, can escape under the inner shroud 38 to the low-pressure zone 60, for removal through vacuum ports 62. From the vacuum ports 62, the dust laden air exits the dust removal head 12 through vacuum output assembly 28 in the air flow 102 directions indicated by arrows in FIGS. 12 and 13. In an exemplary embodiment, outer low-pressure shroud 36 and inner lower pressure shroud 38 are each formed of bent or curved sheet metal, such as made of steel, aluminum or stainless steel, for example. Materials other than described can also be used for components of apparatus 10.

[0057] High pressure air in the high-pressure zone 58, along with the agitation of dust on floor surface 16 caused by the spinning output air nozzles 52, dislodges dust from the surface 16 so that it is entrained in the moving air current. As the dust removal head 12 is pushed across and over floor surface 16, high pressure air from the nozzles 52 blows on every portion of the underlying floor surface 16 as side-to-side motion of the nozzles 52 is accomplished by their motion in spin direction 56. With reference to FIG. 13, in an exemplary embodiment of dust removal head 12b, the cleaning path is about 14 inches wide (measured orthogonal to the primary forward motion direction 70).

[0058] In an exemplary embodiment as shown in FIG. 6, a diameter of the high-pressure zone 58 defined by inner shroud 38 is less than a diameter of the outer shroud 36 so that the low-pressure zone 60 completely surrounds the high-pressure zone 58. Thus, air in any portion of the low-pressure zone 60 can easily find its way to a vacuum port 62. As shown in FIG. 12, the rotating elements including hollow tubes 48 and output nozzles 52 are relatively raised from a floor surface compared to inner shroud 38, which serves as a guard to prevent damage to the rotating parts by impact with material that may be lying on the floor surface 16.

[0059] FIG. 14 is a bottom view of a second exemplary embodiment of a dust removal head 12b. In this embodiment, the air input assembly 34 fluidly communicates pressurized air to two spinning arm assemblies 47, effectively doubling the cleaning path width upon motion of the head 12 in direction 70. In other respects, this dust removal head is similar in construction and operation to the single rotating arm assembly version discussed in more detail above.

[0060] FIG. 16A is a side elevation view of a rotating arm assembly in one embodiment. FIG. 16B is an enlarged view of the right portion of the rotating arm assembly of FIG. 16A. Internal structures are shown in dotted lines, showing the directional change of the air flow 102 through arms 48 and nozzles 52. FIG. 16C is a cross sectional view of an exemplary nozzle 52 having a curved interior surface 104 that effectively concentrates the air flow stream, thereby increasing its discharge coefficient (Cd) at output orifice 54. This increases the effectiveness of dust removal of the exiting air jet. By decreasing the effective channel size between the rotating arm 48 and the exit orifice 54, the discharged air can be concentrated in a more powerful stream.

[0061] While the apparatus 10 is particularly suitable for removing concrete dust from a floor surface for later coating with epoxy or another product application, it is to be understood that the disclosed apparatus can be used in other applications as well, such as for example cleaning sawdust from woodworking panels in preparation for staining. The disclosed apparatus in its operation uses high pressure air to dislodge contaminants such as dust from the surface 16 of interest. The dust laden air is removed with a vacuum via ports 62 so that the contaminants are not released into the workspace. Moreover, the high-pressure air also cleans the surface of dirt and other loose residue, to streamline the surface preparation process by eliminating a separate cleaning step in many cases. After moving the apparatus 10 across a portion of a surface 16, the resulting surface is dust free to a greater extent than can be achieved with a conventional vacuum cleaner or sweep broom. Compared to the conventional concrete preparation methods described in the background, use of apparatus 10 also leads to significant time and labor saving as well as reducing worker fatigue.

[0062] As dust on the surface 16 under the high-pressure zone 58 is dislodged by action of the high pressure and high velocity air stream exiting through nozzles 52, the solid particulates are entrained into the turbulent air current. Inner shroud 38 acts as a buffer so that air flowing around a bottom of the inner shroud 38 and to the low-pressure zone 60 is slowed in velocity so that a vacuum machine attached to the vacuum output assembly 28 can efficiently remove the airborne dust through ports 62 and vacuum output assembly 28.

[0063] For example, a suitable air compressor 24 for connection to vacuum output assembly 28 can output an air stream at a velocity of about 10-12 cubic feet per minute (0.28-0.34 cubic meter/minute) and at a pressure of about 105 pounds per square inch (7.38 kg-force/square centimeter). A small diameter size of orifice 54 outputs air in a high pressure concentrated stream, wherein a suitable nozzle orifice size is about 1/16th inch (1.59 mm). In an exemplary embodiment, orifice 54 is positioned about one quarter inch (6.35 mm) above the floor surface 16. Orienting the orifice 54 at a small acute angle , such as a few radial degrees tilted from the vertical, creates a side force of air exiting the nozzle 52 while keeping the majority of the air force directed at the surface 16 being cleaned. The side force causes rotation of the hollow tubes 48 in spin direction 56 with a high speed of rotation, such as about 2,400 rotations per minute. In some cases, the speed of air exiting orifice 54 can be more than 650 miles per hour (1,046 km/hr).

[0064] In an exemplary embodiment, the volume of air that is removed through vacuum ports 62 is much greater than the output from the nozzles 52. This ensures that all air flow from the high-pressure zone is captured by the vacuum 26 and also allows the vacuum 26, via ports 62 in the low-pressure zone, to pick up excess bulk dust that is sitting loose on the floor surface 16 even before the high-pressure zone 58 passes over that area.

[0065] Referring to leading edge 66, when the dust removal head 12 is moved in a forward direction 70, the low-pressure zone 60 encounters a portion of the floor surface 16 before the high-pressure zone 58 passes over that same area. Thus, much of the loose dust and debris is picked up and vacuumed away through the vacuum ports 62 before even encountering the high-pressure central zone 58. Thus, much less debris is highly disturbed by the high pressure, quickly moving air blasted onto the floor surface 16 by the spinning arm assembly 47, thereby resulting in an overall cleaner work environment with less dust-laden air around the apparatus 10. Because the low-pressure zone 60 substantially surrounds the high-pressure zone 58, this pre-cleaning step is effective in all directions of motion of dust removal head over floor surface 16, including an angled reverse direction pool of the apparatus 10 to allow for redundant forward and rearward cleaning passes of the apparatus 10 over the floor surface 16.

[0066] The high amount of air flow exhausts out the vacuum port 62 pulls air from the low-pressure zone 60 to the high-pressure zone 58 and additionally pulls significant air volume from outside the machine 10 to the low-pressure zone 60. This continuous movement of air from outside of the machine to the exhaust ports 62 creates an air curtain that prevents dust and debris from contaminating the surrounding environment.

[0067] Use of apparatus 10 is particularly beneficial in the many applications, though these described uses are only illustrative and not limiting. One implementation is for dust removal in concrete polishing. Concrete Polishing is the process of grinding a concrete surface with a concrete grinding and polishing machine. The machine is run over the surface area numerous times (typically about 4-8 times). The machine starts out with aggressive diamond tooling to remove a predetermined amount from the top of the concrete surface.

[0068] After a step or two in this polishing process, the surface is grout coated. Grout coating involves applying a liquid resin over the whole area to fill open pores in the concrete. Apparatus 10 removes dust from the concrete pores that would otherwise prevent the grout coat from maximum penetration. After this grout coat hardens, the polishing steps continue.

[0069] Each subsequent step uses progressively finer tooling to remove scratch marks imparted by the previous passes. As the process proceeds, the concrete surface takes on a gloss. The desired gloss result determines how many passes are used and the final grit of the tooling. Vacuuming or dust removal after each pass can be accomplished with apparatus 10.

[0070] After every step of grinding, concrete dust or sand is present, as well as diamond sheds from the grinder tooling. These particles of dust, sand and waste diamonds must be removed; otherwise, they will leave larger scratch marks in the concrete surface that will not be removed by the next step in tooling.

[0071] Another suitable implementation for apparatus 10 is in preparation of a floor surface to accept a paint chip resin coating. The preparation of this type of coating is similar to any resinous coating but as the product is applied, paint chips are introduced into the base layer of resin. These paint chips need to be scraped (to knock off the high peaks of flake sticking up and level them), and the loose chips are swept up, blown with an air blower and/or vacuumed up. A scraper 94 can be attached to the leading edge 66 of apparatus 10 to flatten these high chips; the machine 10 will dislodge excess chips and vacuum them away.

[0072] While specific embodiments of a system 100 are shown and described, it is contemplated that other configurations are also possible. For example, apparatus 10, rather than being a manually pushed device, can instead be controlled remotely, be self-propelled, and/or be robotically programmable and autonomously operable. Moreover, while the illustrated system 100 shows an apparatus 10 that is moveable independent of compressor 24 and vacuum 26, in another embodiment, these components may all be contained on a single larger machine, such as a drivable, ride-on cleaning machine, for example. Such a machine can include power sources to operate the compressor 24 and vacuum 26, including power conversion devices as needed (such as to convert power from an internal combustion engine or other fuel source to electricity, for example). In another system, apparatus 10 may be connected to a dust-producing tool such as a grinder, for example, to remove dust as the grinder works over a surface.

[0073] Non-limiting, illustrative embodiments of a system and method are described. In one aspect, a system 100 comprises a dust removal head 12 comprising an air input assembly 34, a vacuum output assembly 28, a high pressure zone 58 and a low pressure zone 60. In an exemplary embodiment, the air input assembly 34 is configured for connection to a pressurized air source 24. In an exemplary embodiment, the vacuum output assembly 28 is configured for connection to a vacuum machine 26. In an exemplary embodiment, the high pressure zone 58 is in fluid communication with the air input assembly 34. In an exemplary embodiment, the low pressure zone 60 surrounds the high pressure zone 58, is in fluid communication with the high pressure zone 58, and is in fluid communication with the vacuum output assembly 28.

[0074] In an exemplary embodiment, the system 100 comprises the pressurized air source 24. In an exemplary embodiment, the system 100 comprises the vacuum machine 26. In an exemplary embodiment, the high pressure zone 58 comprises a spinning arm assembly 47 that is configured to receive pressurized air from the air input assembly 34. In an exemplary embodiment, the spinning arm assembly 47 comprises a substantially longitudinal conduit (see the interior dotted lines in FIG. 16B) for the pressurized air. In an exemplary embodiment, a nozzle 52 is oriented at an acute angle alpha relative to a direction that is orthogonal to the longitudinal conduit (see FIGS. 15A and 15B). In an exemplary embodiment, the acute angle alpha is between about 10 degrees and about 20 degrees. In an exemplary embodiment, the spinning arm assembly 47b comprises an arm 48b having an airfoil shape.

[0075] In an exemplary embodiment, the high pressure zone 58 is defined by a first shroud 18 covering the spinning arm assembly 47. In an exemplary embodiment, the low pressure zone 60 comprises a second shroud 38 surrounding the first shroud 18. In an exemplary embodiment, the second shroud 38 extends closer to a surface 16 from which dust is to be removed than does the spinning arm assembly 47 (see FIG. 12). In an exemplary embodiment, the second shroud 38 extends closer to a surface 16 from which dust is to be removed than does the first shroud 18 and comprises a plurality of apertures 98 between an edge of the first shroud and an edge of the second shroud (see FIGS. 6C and 12). In an exemplary embodiment, the low pressure zone 60 comprises a third shroud 36 surrounding the second shroud 38.

[0076] In an exemplary embodiment, the dust removal head 12 has a forward motion direction 70 defining a leading edge 66 and a trailing edge 68, and wherein the low pressure zone 60 has a greater volume proximate the trailing edge 68 than proximate the leading edge 66. In an exemplary embodiment, the low pressure zone 60 has a greater volume proximate the vacuum output assembly 28 than distal from the vacuum output assembly 28. In an exemplary embodiment, the dust removal head 12 has a forward motion direction 70 defining a leading edge 66 and a trailing edge 68, the system 100 comprising a scraper 94 positioned forward of the leading edge 66 (see FIG. 2B).

[0077] In another aspect, a method of removing dust from a surface 16 using a machine 10 is described. The method comprises directing pressurized air toward the surface 16 to dislodge the dust from the surface and entrain the dust in a moving air stream within a high pressure zone shroud 18, thereby producing a dust-entrained air flow. The method also comprises conveying the dust-entrained air flow to a low pressure zone container 36, 38, 64 and removing the dust-entrained air flow from the low pressure zone container 36, 38, 64 using a vacuum 26.

[0078] In an exemplary embodiment, directing pressurized air toward the surface 16 comprises blowing the pressurized air from opposed ends of a rotating arm assembly 47. In an exemplary embodiment, conveying the dust-entrained air flow to the low pressure zone container 36, 38, 64 comprises moving the dust-entrained air flow between the high pressure zone shroud 18 and the surface 16. In an exemplary embodiment, conveying the dust-entrained air flow to the low pressure zone container 36, 38, 64 comprises moving the dust-entrained air flow through a plurality of apertures 98 of the low pressure zone container 38.

[0079] Although the subject of this disclosure has been described with reference to several embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the disclosure. In addition, any feature disclosed with respect to one embodiment may be included in another embodiment, and vice-versa.