Apparatus and method for providing a modular abrasive blasting and recovery system

A modular abrasive particle blasting system comprises an abrasive blast assembly including at least one blast vessel for delivering blast particles to an abrasive blasting system. The abrasive blast assembly is mounted within a first skid. An abrasive recycling assembly includes at least one vacuum hopper for receiving grit retrieved from an abrasive blasting process. The abrasive recycling assembly is mounted within a second skid. The first and second skids comprise mounting members at a top section and a bottom section of each of the first and second skids to permit mounting of the first and second skids in alternate stacked arrangements whereby the first skid is selective mounted above and below the second skid. The same skid principal may be used to provide a variety of skids, including blast skid, vacuum skid, recycle skid, storage skid, air dryer skid, dust collector skid and or dehumidification skid.

FIELD OF THE INVENTION

This present invention relates to devices and methods for abrasive particle blasting as well as cleaning, separating and reclaiming spent abrasive blasting material that have been employed during an abrasive blasting process in general and, more particularly, to a system for providing modular and stackable abrasive particle blasting units and grit recycling systems.

BACKGROUND OF THE INVENTION

Abrasive blasting of steel structures, such as ships and highway bridges, is a necessary step in maintenance of structures. In particular, abrasive blasting is a precursor to repainting of steel structures. One particular problem encountered with structures such as bridges is that the past painting history of the structure typically will include a lead-based paint. Abrasive blasting tends to liberate lead dust from such structures. Lead dust however, is considered quite toxic and is increasingly regulated. One approach to controlling environmental contamination from the lead dust resulting from abrasive blasting is to recover all of the dust resulting from an abrasive blasting procedure. If the abrasive blasting is accomplished using sand particles, the lead dust ends up mixed with the sand particles. This results in an undesirably high quantity of hazardous waste for subsequent disposal. A more desirable alternative is to employ a reusable steel abrasive particle. Steel is denser than sand and therefore more effectively retains blasting energy.

The most commonly used type of abrasive blasting media currently used is silica sand, fine glass beads, steel shot, steel grit, stainless steel shot, cut wire, grit or similar sized pellets, etc. It is possible to repeatedly use the same abrasive blasting material (or media) several times, if the abrasive blasting material is properly cleaned between each use.

One consequence of the abrasive blasting process on the abrasive blasting materials resulting from high velocity impacting on steel surfaces being cleaned causes them to abrade and generate contaminants such as dirt, paint, mill scale, and rust from the treated surface. At the same time a certain amount of fractured, fine abrasive particles (dust) is also produced.

Various types of devices for cleaning and reclaiming spent abrasive blasting media are available in the related art. Typically, in such a device, the used abrasive blasting media is vacuumed up and carried in an airstream to a cleaning and separating device. Lightweight contaminants are removed by air-washing, while large particulate contaminated material is separated by a separating device.

While known devices for cleaning and reclaiming spent abrasive blasting media have proven to be acceptable for various abrasive blasting media cleaning and reclaiming applications, such devices are nevertheless susceptible to improvements that may enhance their performance, applicability, cost and attractiveness. With this in mind, a need exists to develop a modular approach for arranging different components of the blast skid, recycle skid and vacuum skid as well as other components related to the blasting process.

SUMMARY OF THE INVENTION

A modular abrasive particle blasting system comprises an abrasive blast assembly including at least one blast vessel for delivering blast particles to an abrasive blasting system, said abrasive blast assembly being mounted within a first skid; an abrasive recycling assembly including at least one vacuum hopper for receiving grit retrieved from an abrasive blasting process, said abrasive recycling assembly being mounted within a second skid; wherein said first and second skids comprising mounting members at a top section and a bottom section of each of said first and second skids to permit mounting of said first and second skids in alternate stacked arrangements whereby said first skid is selective mounted above and below said second skid.

The modular abrasive particle blasting system further comprises an abrasive vacuum assembly including a vacuum dust collector, said abrasive vacuum assembly being mounted within a third skid, wherein said third skid comprises additional mounting members to permit said third skid to be selectively mounted above and below at least one of said first and second skids.

The modular abrasive particle blasting system according to the invention provides a modular blast assembly and a modular recycling assembly which are interconnected by pneumatic hoses. The individual skids are dimensioned the same to mates with each other.

With the structure of the skids as described above, it is possible to provide modular units of abrasive blasting and recovery which may be stacked or disposed side-by-side. In the preferred embodiment, the modular skids are interconnected by hoses therefore the different skids may be disposed in any stacked arrangement with the blast skid being above or below the recycle skid. Additionally all three skids may be stacked in any order and additional skids may be provided. Likewise, the same modular skids may be set side-by-side and interconnected by hoses during use and operation.

It is also noted that while the above description shows only three skids, the present invention is not limited to the specific structure and additional skids may be provided. For example, the present invention may be modified to include a blast skid, a vacuum skid, a recycle skid, a storage skid, an air dryer skid, a dust collector skid and or a dehumidification skid. Likewise, a ladder skid may be provided to include a ladder to permit an operator to climb to a desired position adjacent the system skids mentioned above.

Other aspects of the invention, including apparatus, systems, methods, and the like which constitute part of the invention, will become more apparent upon reading the following detailed description of the exemplary embodiments and viewing the drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS AND EXEMPLARY METHODS

Reference will now be made in detail to exemplary embodiments and methods of the invention as illustrated in the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the drawings. It should be noted, however, that the invention in its broader aspects is not limited to the specific details, representative devices and methods, and illustrative examples shown and described in connection with the exemplary embodiments and methods.

This description of exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “upper”, “lower”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. Additionally, the word “a” as used in the claims means “at least one”.

FIGS. 1-3of the drawings illustrate a system and a process for separation and recovery (reclaiming, recycling) of used (or spent) abrasive blasting material (media) according to an exemplary embodiment of the present invention indicated generally by reference numeral10. The system10is an abrasive blasting material recycling system that includes vacuum recovery, classification, and air blasting units. The system10has four major subsystems: vacuum, classification, compressed air dryer, and blasting, and a control panel11. According to the conventional arrangement of the present invention, the apparatus10is a mobile apparatus in the form of a self-contained vehicle12, such as a trailer, having one or more wheels and axle assemblies14, one or more telescopically extensible trailer stabilizer antis15that may extend from the trailer12and can be deployed therefrom to support and stabilize the trailer12during the operation of the mobile apparatus10. In accordance with the aspects of the present invention, the components of the system10are mounted within separate modular skids. In other words, the components of the apparatus10according to the exemplary embodiment of the present invention are mounted in modular skids as opposed to the conventional manner of mounting the components on a single trailer. In accordance with the present invention, the components of the mobile apparatus10are mounted on separate skids.

The apparatus10according to the exemplary embodiment of the present invention comprises a vacuum recovery unit16. The vacuum recovery unit16includes a vacuum storage hopper (bin)18for receiving and storing (i.e., recovery of) spent or used, dirty abrasive blasting material, such as abrasive grit. The spent dirty (i.e., contaminated) abrasive blasting material, generally denoted with the reference numeral22, is composed of the abrasive blasting material (media)23and various contaminants24including large contaminants (large trash items), paint chips and dust. It is desirable to remove the contaminants24from the contaminated abrasive blasting material22and recover clean abrasive blasting material23for reuse, as best shown inFIG. 3.

The contaminated abrasive blasting material22is initially delivered into the vacuum recovery unit16via a vacuum pick-up17. The vacuum pick-up17is in fluid communication with a vacuum pump28selectively powered by a prime mover29, i.e. a machine that transforms energy from thermal, electrical or pressure energy to mechanical energy. In the exemplary embodiment of the present invention, the prime mover29is in the form of an internal combustion engine, such as a diesel engine. It will be appreciated that any other type of prime mover, such as an electric motor, is within the scope of the present invention. Both the vacuum pump28and the diesel engine29are mounted on the trailer12. As illustrated inFIGS. 3 and 4, the vacuum recovery unit16further includes a first (or primary) screening device201disposed in an upper portion of the vacuum storage hopper18. The first screening device201is provided with a screen having a plurality of holes, known as “mesh.” The primary screening device201is provided with the screen having oversized screen holes for screening (separating) and reclaiming the contaminated abrasive blasting material from large contaminants (or large trash items).

The dirty (dusty) air is removed from the vacuum storage hopper18to a vacuum dust collector42where the air is filtered by primary filters44and secondary filters45, then passes through a vacuum tube46to the vacuum pump28, where it is discharged into the atmosphere. The dust removed from the dirty air is deposited into a dust container50through a double dump dust discharge49, shown inFIG. 3.

The apparatus10further comprises a classifier unit30in fluid communication with the vacuum recovery unit16. The classifier unit30includes a dust separator32with an air wash intake33, a second (or secondary) screening device202disposed in an upper portion of classifier bin34, and a magnetic drum separator36disposed downstream of the secondary screening device202. The classifier bin34has a funneled lower portion35with an outlet opening facing the magnetic separator36. The magnetic separator36is disposed in a separator bin38located beneath (downstream) the classifier bin34. The separator bin38includes a contaminant section391and an uncontaminated section392.

After screening through the primary screening device201, the recovered contaminated abrasive blasting material22from the dirty grit transporter27is transported to the classifier unit30where it is de-dusted in the air wash of the dust separator32, screened again in the secondary screening device202, passes over the magnetic drum separator36, and is then transferred to a recycled grit storage hopper40.

The contaminated abrasive blasting material22(in this case, the mixture of the abrasive blasting material and the remaining contaminates, separated by the secondary screening device202from the medium-size contaminants) falls by gravity through the secondary screening device202into the funnel-shaped lower portion35of the classifier bin34. The medium-size contaminants, such as paint chips, are transported to and deposited into the contaminant section391of the separator bin38. The contaminated abrasive blasting material22(with the remaining contaminates but without the medium-size contaminants) is then deposited into the lower portion35of the classifier bin34.

The magnetic separator36comprises a drum at least a portion of which is magnetized. Consequently, as the contaminated abrasive blasting material22is supplied to the magnetic separator35, the magnetic contaminants24are separated therefrom and conveyed to the contaminant section391of the magnetic separator bin38, while the reclaimed (recycled), clean abrasive blasting material23is fed to the uncontaminated section392of the magnetic separator bin38. The recycled abrasive blasting material23(substantially without the contaminants, i.e., with negligible amount of contaminants, such as dust) is then deposited into the recycled grit storage hopper40.

The dirty (dusty) air from the dust separator32is removed to a recycle collector52(using vacuum created by a recycle blower54), where the air is filtered by filters55, then passes to the vacuum dust collector42where the air is filtered, then discharged into the atmosphere. The dirty (dusty) air from the contaminant section391of the magnetic separator bin38is removed from the contaminant section391of the magnetic separator bin38to the vacuum dust collector42where the air is filtered by the primary filters44and secondary filters45, then passes to the vacuum pump28where it is discharged into the atmosphere. The dust removed from the dirty air is deposited into a dust container50, as best shown inFIG. 3.

The recycled (reclaimed) abrasive blasting material23is then transported to a blast pot unit58and deposited into a recycled grit storage hopper60. The dirty (dusty) air from the recycled grit storage hopper60is removed to the recycle collector52where the air is filtered, then passes to the vacuum dust collector42where the air is filtered again, then discharged into the atmosphere. The blast pot unit58further includes a plurality of blast pots92. The recycled (reclaimed) abrasive blasting material23stored in the recycled grit storage hopper60is loaded in to the blast pots92as needed. Compressed air from an external air compressor(s) passes through a compressed air dryer94where it is prepared for use in the blast pot unit58to propel the recycled abrasive blasting material23through hoses96, where it is directed at steel and other substrates for corrosion, paint, and contaminate removal. The compressed air dryer94is connected to the external air compressor(s) via a compressed air connector97. Before entering the compressed air dryer94, the compressed air passes through a compressed air intercooler98, which is provided with a cooling fan unit100.

After being blasted, the spent abrasive blasting material22is vacuumed back into the vacuum recovery unit16to start the recycling process again.

While the components of the system10have been shown inFIGS. 1-3in their conventional side-by-side arrangement, the present invention provides separate and modular skids for the different components of the abrasive blasting and recovery system10.

By way of example, a top view of a first skid100; i.e., a blast skid, is illustrated inFIG. 4and includes access ports110and shows a top of a grit or media storage hopper120.FIG. 4also shows four lift corners130aof the first skid100which will be described in more detail below.FIG. 5illustrates a bottom view of the first skid100and shows six blast pot vessels140and a control panel150.FIG. 5also shows optional fork lift pocket160to permit transport of the first skid100by a fork lift.FIG. 5also shows four lift corners130bof the first skid100.FIG. 6is an end view of the first skid100and shows the access ports110, the media storage hopper120and blast vessels140.FIG. 6also illustrates the top lift corners130aand the bottom lift corners130b. The top and bottom lift corners130a,130bare fixed, preferably by welding, to the upright frame members105which are formed preferably of a steel of sufficient strength as known in the art.FIG. 7is a side view of the first skid100shown inFIGS. 4-6. As shown inFIG. 7, the first skid includes the fork lift pockets160, the media storage hopper, the access ports110and the control panel150. Also shown inFIG. 7are the top lift corners130aand the bottom lift corners130b.Again, the top and bottom lift corners130a,130bare fixed, preferably by welding, to the upright frame members105which are formed preferably of a steel of sufficient strength as known in the art. The first skid also includes lateral frame members107and preferably angled frame members (not shown).

By way of example, a top view of a second skid200; i.e., a vacuum skid, is illustrated inFIG. 8and includes a vacuum exhaust210, a vacuum blower220, and a vacuum dust collector250. Also shown is a control panel240. In accordance with the present invention, the second skid200includes top lift corners230awhich are formed and shaped in the same manner as the top lift corners130aof the first skid100.FIG. 9is a bottom view of the second skid200and shows the vacuum blower220, the control panel240, and the vacuum dust collector250.FIG. 9also illustrates a blower exhaust260, a waste discharge270, an electric motor280, and a vacuum intake silencer290. Notably,FIG. 9shows the four bottom lift corners230bof the second skid200which are formed and shaped in the same manner as the bottom lift corners130bof the first skid100.FIG. 10is a side view of the second skid200and shows the control panel240, the waste discharge270, the electric motor280, and the vacuum dust collector250. Also shown inFIG. 10is an exhaust silencer295. As with the first skid100, the second skid also includes fork lift pockets265.FIG. 10also illustrates the top and bottom lift corners230a,230bwhich are fixed by welding to upright frame members205. The second skid also includes lateral frame members207and angled frame members208.FIG. 11is an end view of the second skid200and shows the vacuum blower220, vacuum dust collector250, the cooling air inlet silencer290, and the exhaust silencer295. The second skid200as shown inFIG. 11includes the top and bottom lift corners230a,230bas well as the upright frame members205and lateral frame members207.

FIG. 12illustrates a top view of a third skid300; i.e., a recycle skid300. The third recycle skid illustrated inFIG. 12includes a vacuum hopper with screen310and a media classifier320with screen, air wash and magnetic drum separator. As with the first and second skids100,200the third skid includes top lift corners330a.FIG. 13is a bottom view of the third skid300and illustrates the classifier320and the vacuum hopper310.FIG. 13further illustrates vacuum source hose connections340as well as a grit transfer vessel350and a waste outlet360. The third skid300further includes forklift pockets370and bottom corner lifts330b.FIG. 14is a side view of the third skid300and illustrates the classifier320, the vacuum hopper310, the waste outlet360, and the grit transfer vessel350.FIG. 14also illustrates a classifier air wash fan380and the fork lift pockets370. As with the structure of the first and second skids, the third skid includes the top and bottom lift corners330a,330b, upright frame members305and the lateral frame members307.FIG. 15is an end view of the third skid300and illustrates the air wash fan380, the waste outlet360, the magnetic drum separator and classifier320and grit transfer vessel350. The structure of the skid300includes the upright frame members305, lateral frame members307and angled frame members308.

In accordance with the primary purpose of the present invention, the skids100,200,300ofFIGS. 4-15provide a modular system whereby different components of the blasting and recovery system shown inFIGS. 1-3may be stacked or disposed side-by-side depending on the environment of their use and deployment. For example,FIG. 16shows one arrangement whereby the recycle skid300is stacked on top of the blast skid100. Alternatively,FIG. 17shows an arrangement whereby two vacuum skids200are stacked one on top of the other. Because these skids100,200,300are interconnected by hoses only, it is possible to either stacked these skids100,200,300as shown inFIGS. 16 and 17or place these same skids side-by-side as illustrated schematically inFIG. 3.

FIGS. 18a-18eshow five different views of the lift corners130a,130b,230a,230b,330a,330b. When viewed from the top and bottom as shown inFIGS. 18dand18b, the lift corner has an oblong opening400adapted to receive an interlocking key element500shown inFIGS. 19a-19e. As shown inFIG. 20, a blast skid100is located then the interlocking key500is inserted into the oblong opening400of the lift corners130a; i.e., the lower (oblong) cone element502is inserted into oblong opening400. The interlocking key has a main body505formed with bearing legs506,507which come to rest on the lower skid100. The cones502,504are adapted to rotate with respect to the main body505. Next, the recycle skid300is lifted (by a crane or other lifting device) above the blat skid100and lowered onto the blast skid100so that the top (oblong) cone element504of the interlocking key500is received into a corresponding oblong opening400of each lift corner330bof the recycle skid300. The upper skid300comes to rest on the bearing legs506,507to maintain a gap “g” between the skids100,300. Once the top skid300is correctly positioned on the lower skid100, the interlocking key is rotated via handle508so that the oblong cone is rotated. Upon rotation of the oblong cones502,504, the interlocking key is locked in place because the oblong cones are within the lift corners and rotated so that the oblong shape of the cones502,504is no longer aligned with the oblong opening400of the lift corners. Like a key into a lock, once turned, e.g.90degrees, the interlocking key500is fixed within the lift corners.

With the structure of the skids as described above, it is possible to provide modular units of abrasive blasting and recovery which may be stacked or disposed side-by-side. In the preferred embodiment, the modular skids100,200,300are interconnected by hoses therefore the different skids100,200,300may be disposed in any stacked arrangement with the blast skid100being above or below the recycle skid300. Additionally all three skids100,200,300may be stacked in any order. Likewise, the same modular skids may be set side-by-side and interconnected by hoses during use and operation.It is also noted that while the above description shows only three skids, the present invention is not limited to the specific structure and additional skids may be provided. For example, the present invention may be modified to include a blast skid, a vacuum skid, a recycle skid, a storage skid, an air dryer skid, a dust collector skid and or a dehumidification skid. Likewise, a ladder skid600may be provided to include a ladder610to permit an operator to climb to a desired position adjacent the system skids mentioned above.FIGS. 21a-21fshow top and side views of an exemplary blast skid (FIG. 21a), a vacuum skid (FIG. 21b), a classifier skid (FIG. 21c), an air dryer skid (FIG. 21d), a dust collector skid (FIG. 21e), and a ladder skid600(FIG. 21f). Of course the exact mechanical components provided within each skid may be modified and varied depending on the intended use and purpose to be achieved by the operator. However, each skid is sized (11′×12′) to match one another so that each skid may mate with a corresponding skid.

The foregoing description of the exemplary embodiments of the present invention has been presented for the purpose of illustration in accordance with the provisions of the Patent Statutes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments disclosed hereinabove were chosen in order to best illustrate the principles of the present invention and its practical application to thereby enable those of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated, as long as the principles described herein are followed. Thus, changes can be made in the above-described invention without departing from the intent and scope thereof. It is also intended that the scope of the present invention be defined by the claims appended thereto.