Not Applicable
Not Applicable
The present invention relates generally to blast cabinets and, more particularly, to a uniquely configured centrifuge media separator that may be included with the blast cabinet and which is specifically adapted to separate blast particulate from fine particulate such that the blast particulate may be recycled through the blast cabinet while the fine particulate may be removed from the blast cabinet in order to improve the visibility of a workpiece being blasted within the blast cabinet.
Blast cabinets are typically utilized to clean or generally prepare surfaces of a workpiece by directing high pressure fluid containing abrasive blast media or blast particulate toward the workpiece. The abrasive blast particulate is typically a relatively hard material such as sand, sodium bicarbonate (i.e., baking soda), metallic shot or glass beads although many other materials may be selected for use as the blast particulate.
During blasting, the blast particulate bounces off of the workpiece and is generally violently thrown about within the enclosure such that a portion of the blast particulate normally breaks down into smaller dust-like particles hereinafter referred to as fine particulate. In addition, surface coatings, dirt and scale that are abraded from the workpiece by the blast media contribute to the formation of fine particulate within the enclosure. The fine particulate is too small to be effective as a blast medium and therefore must be eventually removed from the blast cabinet. In addition, the fine particulate is of such small size such that it may be suspended in the air within the enclosure of the blast cabinet. Over time, the gradual buildup of the fine particulate can create a foggy or clouded environment within the enclosure which visually impairs or obstructs the operator's view of the workpiece. Due to health and safety regulations and environmental restrictions, the particulate-filled air cannot simply be exhausted to the atmosphere. Rather, the particulate-filled air must be filtered prior to exhaustion in order to remove the fine particulate carried therein.
Accordingly, many prior art blast cabinets are ventilated and include filters such that at least a portion of the fine particulate may be purged from the air. The filters may be configured as a replaceable cartridge filter or as a tube style filter. Regardless of its specific configuration, the filter traps the fine particulate during continuous exhaustion of the air from the enclosure. In this manner, visibility of the enclosure is enhanced such that the operator may more clearly observe the workpiece during blasting. Unfortunately, gradual buildup of the fine particulate on the filter reduces its filtering efficiency such that the filter must be periodically cleaned and/or replaced. In addition to filtering the fine particulate, the filter may also trap some of the blast particulate. The gradual buildup of the blast particulate increases the frequency of filter replacement. Furthermore, blast particulate which may otherwise be recycled is unintentionally discarded during replacement of the filter. Continuous supplementing of the blast particulate to replace the discarded blast particulate results in an increase in the operating cost of the blast cabinet.
As can be seen, there exists a need in the art for a simple blast cabinet having the capability to purge fine particulate from air prior to its exhaustion out of the enclosure in order to improve the operator's visibility of the workpiece within the enclosure. In addition, there exists a need in the art for a blast cabinet wherein blast particulate may be separated from fine particulate such that the blast particulate may be recycled through the blast cabinet. Furthermore, there exists a need in the art for a blast cabinet wherein the frequency of filter replacement is reduced such that the overall operating cost of the blast cabinet is reduced. Finally, there exists a need in the art for a blast cabinet wherein the incorporation of the centrifuge media separator eliminates the need for a filter.
In accordance with the present invention, there is provided a centrifuge media separator for a blast cabinet. The centrifuge media separator separates the blast particulate from the fine particulate in order to purge the fine particulate from an interior of the blast cabinet so as to increase the visibility of a workpiece being blasted. In addition, the centrifuge media separator allows for reclaiming or recycling of blast particulate that has not been reduced into particulate of smaller size (i.e., fine particulate).
The blast cabinet may be comprised of a housing of generally inverted pyramid shape such that spent blast particulate may be funneled downwardly toward a lower portion of the housing for recycling. The housing has an enclosure with arm holes to which two gloves may be attached. The housing may also include a window such that an operator may reach though the arm holes to grasp and manipulate the workpiece during blasting. High pressure, high velocity fluid such as air acts as a carrier medium to carry blast particulate for high velocity discharge onto surfaces of the workpiece to remove coatings from or otherwise prepare the workpiece surfaces.
Mounted upon an upper portion of the housing may be the centrifuge media separator which has an air passageway through which the blast media may be drawn by a low pressure source such as a blower. The centrifuge media separator is fluidly connected to the enclosure of the blast cabinet. The low pressure source is fluidly connected to the centrifuge media separator and is configured to draw air into the inlet and exhaust air through the central opening such that the blast media may be drawn upwardly from the enclosure and into the air passageway wherein the blast particulate may be separated from the fine particulate. The blower is configured to ventilate the enclosure by providing low pressure in an area surrounding the centrifuge media separator. The low pressure provided by the blower draws spent portions of the blast media into the centrifuge media separator for subsequent separation into blast particulate and fine particulate.
The centrifuge media separator is comprised of an upper panel, a lower panel, and an outer wall extending between the upper panel and the lower panel. The upper panel has a central opening formed in a central portion thereof through which the fine particulate may be exhausted. Both the upper panel and the lower panel may be generally flat while the outer wall may be curvilinear and may be formed in a generally spiral configuration of generally decreasing radius. The inlet and the outlet of the air passageway may be generally located adjacent to one another with the outlet being disposed within the air passageway.
The outer wall may include at least one particulate escape aperture formed therein such that the blast particulate may be exhausted from the air passageway for subsequent recycling through the blast cabinet. An air foil may be mounted on the outer wall to facilitate exhaustion of the blast particulate through the escape aperture. The air foil may be a separate component that is mounted on the outer wall or it may be integrally formed with the outer wall. An extension may be mounted on the outer wall and may extend between the upper and lower panels in generally alignment with the outer wall such that the outlet is located downstream of the inlet. The extension may be included to prevent a reversal of flow through the air passageway. The air passageway may be configured such that its cross sectional area generally decreases along a direction of the flow of the air from the inlet to the outlet.
In operation, the centrifuge media separator 30 may be attached to the blower such that the blower creates an area of low pressure adjacent the central opening in order to draw air into the inlet. The air contains a combination of blast particulate and fine particulate. Because the air passageway 32 circles about itself in the generally spiral configuration, particulate having a density greater than the air (i.e., the blast particulate) is centrifugally directed toward the outer wall. Upon reaching the escape aperture, the blast particulate is exhausted from the air passageway.
Downstream of the escape aperture, the air circulating through the air passageway may contain fine particulate that may be drawn through the central opening formed in the upper panel due to the area of low pressure formed by the blower. The area of low pressure created by the blower is preferably such that fine particulate is drawn through the central opening while the larger size of the blast particulate prevents its passage through the central opening. Rather, the blast particulate recirculates through the air passageway and is redirected back to the inlet such that the blast particulate might pass through the escape aperture.
An illustrative and presently preferred embodiment of the invention is shown in the accompanying drawings in which:
Referring now to the drawings wherein the showings are for purposes of illustrating the present invention only and not for purposes of limiting the same, the invention is directed to a centrifuge media separator 30 that is specifically configured to separate blast media. The blast media is generally comprised of blast particulate 18 and fine particulate 20. The centrifuge media separator 30 separates the blast particulate 18 from the fine particulate 20 in order to purge the fine particulate 20 from an interior of the blast cabinet 10 so as to increase the visibility of a workpiece 24 being blasted by a pressure hose (not shown) within the blast cabinet. In addition, the separation of the blast particulate 18 from the fine particulate 20 allows for reclaiming or recycling of the blast particulate 18 through the blast cabinet 10 in order to lower operating costs.
Referring to
The housing 48 of the blast cabinet 10 may also include at least one door (not shown) allowing access into the enclosure 12 such that the workpiece 24 may be inserted thereinto and removed therefrom. The pressure hose is a conduit for a high pressure, high velocity fluid. The fluid acts as a carrier medium and carries blast particulate 18 for high velocity discharge onto surfaces of the workpiece 24 in order to remove coatings from or otherwise prepare the workpiece 24 surfaces, as will be described in greater detail below. The fluid may be a gas such as air as may be utilized in the blast cabinet 10 of
The size of the blast particulate 18 and material from which the blast particulate 18 is fabricated is based upon the workpiece 24 to be blasted. The blast particulate 18 may be sand, sodium bicarbonate (i.e., baking soda), metallic shot, glass beads, etc. The blast particulate 18 may have a greater density relative to the carrier medium. In cleaning applications, the blast particulate 18 may be sand having a size of about sixty microns. When the sand blast particulate 18 is projected out of the pressure hose and onto the workpiece 24, a portion of the sand may break down into fine particulate 20 that is too small to be effective as a blast particulate 18.
Mounted upon an upper portion of the housing 48 may be the centrifuge media separator 30. The centrifuge media separator 30 has an air passageway 32 through which the blast media may be drawn by a low pressure source 52 such as a blower mounted on the blast cabinet 10. The centrifuge media separator 30 is fluidly connected to the enclosure 12 of the blast cabinet 10. The low pressure source 52 is fluidly connected to the central opening 36 and is configured to draw air into the inlet 34 and exhaust air through the central opening 36. In this manner, the blast media may be drawn upwardly from the enclosure 12 and into the air passageway 32 wherein the blast particulate 18 may be separated from the fine particulate 20. Optionally, a filter 22 may be provided with the blast cabinet 10 to filter excess amounts of fine particulate 20 leaving the air passageway 32 prior to exhaustion out of the blast cabinet 10. The blower may be mounted on the blast cabinet 10 above the centrifuge media separator 30. The blower is configured to ventilate the enclosure 12 by providing low pressure in an area surrounding the centrifuge media separator 30. The low pressure provided by the blower draws spent portions of the blast media into the centrifuge media separator 30 for subsequent separation into blast particulate 18 and fine particulate 20.
Referring now more particularly to
As shown in
Importantly, the outer wall 40 may include at least one particulate escape aperture 44 formed therein such that the blast particulate 18 may be exhausted from the air passageway 32 for subsequent recycling through the blast cabinet 10. The outer wall 40 may include an air foil 50 mounted thereon on a downstream side of the escape aperture 44. The air foil 50 may be configured to create a local area of low pressure adjacent the escape aperture 44. As shown in
An extension 43 may optionally be included with the centrifuge media separator 30. Mounted on the outer wall 40, the extension 43 may extend between the upper and lower panels 54, 56 and may extend from and be disposed in general alignment with the outer wall 40 such that the outlet 38 is located downstream of the inlet 34 along a direction of the flow A. The extension 43 may be a separate component that extends from the outer wall 40 or the extension 43 may be integrally formed with the outer wall 40. By including the extension 43 with the centrifuge media separator 30, reversal of the flow A through the air passageway 32 may be minimized or prevented.
Referring still to
The upper panel 54, lower panel 56 and outer wall 40 collectively define the curvilinear air passageway 32 having an inlet 34 and an outlet 38. The inlet 34 may be rectangularly shaped due to the orthogonal relation of the upper and lower panels 54, 56 and the outer wall 40. Similarly, the outlet 38 may also be partially rectangularly shaped due to the orthogonal relation of the upper and lower panels 54, 56 and the outer wall 40 and inner ring 42. However, the inlet 34 may be configured in a variety of alternative shapes as may be provided by including an inlet 34 extension 43 of, for example, cylindrical shape. Conversely, the outlet 38 configuration may be generally determined by the shape of the upper and lower panels 54, 56 and the shape of the outer wall 40 and inner ring 42. The inlet 34 is configured to allow a flow of air to enter the air passageway 32 and circulate therethrough toward the outlet 38.
As can be seen in
Referring now more particularly to
In use, the centrifuge media separator 30 may be attached to the blower as mentioned above. The blower creates an area of low pressure adjacent the central opening 36 and in an area adjacent the inner ring 42, if included with the centrifuge media separator 30. The area of low pressure draws air into the inlet 34. As was earlier mentioned, the air contains a combination of blast particulate 18 and fine particulate 20. Because the centrifuge media separator 30 is configured such that the air passageway 32 circles about itself, particulate having a density greater than the air (i.e., the blast particulate 18) tends to be centrifugally directed toward the outer wall 40. The blast particulate 18 may circulate within the centrifuge media separator 30 in a sliding manner against the outer wall 40.
When the blast particulate 18 reaches the escape aperture 44, the blast particulate 18 is exhausted from the air passageway 32. A pressure differential may exist between an inside and outside of the air passageway 32 at an area adjacent the escape aperture 44. The outside of the air passageway 32 may have a lower pressure compared to that on the inside of the air passageway 32 such that the blast particulate 18 is drawn to the outside of the air passageway 32. Once outside of the air passageway 32, gravity may draw the blast particulate 18 downwardly into a blast particulate 18 hopper such that the blast particulate 18 can be reused. The pressure differential between the inside and outside of the air passageway 32 may be increased with the addition of the air foil 50 such that the separating efficiency of the centrifuge media separator 30 is enhanced.
Downstream of the escape aperture 44, the air circulating through the air passageway 32 may contain fine particulate 20. The air with fine particulate 20 may be drawn through the central opening 36 formed in the upper panel 54 due to the application of low pressure by the blower. If the centrifuge media separator 30 includes an inner ring 42, the air may pass under and around the inner ring 42 such that it may be drawn upwardly through the central opening 36. The low pressure may be sufficient to draw air with fine particulate 20 through the central opening 36 but not insufficient to draw the blast particulate 18 therethrough. As such, the blast particulate 18 downstream of the escape aperture 44 may be recirculated through the air passageway 32 and redirected back to the inlet 34 such that the blast particulate 18 might pass through the escape aperture 44.
As stated above, the air passageway 32 may have a generally decreasing cross sectional area in a direction of flow A from the inlet 34 to the outlet 38. The decreasing cross sectional area of the air passageway 32 increases the air velocity as the air progresses downstream of the inlet 34. Preferably, the air flow is laminar once the air reaches the escape aperture 44 wherein the blast particulate 18 may be centrifugally directed to the outer wall 40 such that the blast particulate 18 may exit the particulate escape aperture 44.
Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.
Number | Name | Date | Kind |
---|---|---|---|
722464 | Stevens | Mar 1903 | A |
1751719 | Uhri, Jr. | Mar 1930 | A |
2324250 | Voerge | Jul 1943 | A |
2376287 | Sorrentino | Apr 1945 | A |
2376616 | Oechsle et al. | May 1945 | A |
2387193 | Swenarton | Oct 1945 | A |
2440643 | Pettinos | Apr 1948 | A |
2587184 | Marjama | Feb 1952 | A |
2669809 | McGrath | Feb 1954 | A |
2717476 | Myers | Sep 1955 | A |
3424386 | Maasberg et al. | Jan 1969 | A |
3906674 | Stone | Sep 1975 | A |
D239155 | Kent | Mar 1976 | S |
3953184 | Stockford et al. | Apr 1976 | A |
3970437 | Van Diepenbroek et al. | Jul 1976 | A |
4026687 | Berz | May 1977 | A |
4047907 | Knutsson et al. | Sep 1977 | A |
4099937 | Ufken et al. | Jul 1978 | A |
4140502 | Margraf | Feb 1979 | A |
4144043 | Johnston | Mar 1979 | A |
4156600 | Jacobson | May 1979 | A |
4201256 | Truhan | May 1980 | A |
4202142 | Van Fossen | May 1980 | A |
4223748 | Barendsen | Sep 1980 | A |
4230468 | Rebours et al. | Oct 1980 | A |
D257774 | Pierson | Jan 1981 | S |
4244715 | Eisenbarth | Jan 1981 | A |
4253610 | Larkin | Mar 1981 | A |
4266673 | Haidlen et al. | May 1981 | A |
4272260 | Klein et al. | Jun 1981 | A |
4275531 | Van Fossen | Jun 1981 | A |
4285707 | Pfenninfer | Aug 1981 | A |
4286974 | Schminke | Sep 1981 | A |
4330400 | Schmidt | May 1982 | A |
4336040 | Haberl | Jun 1982 | A |
4348057 | Parenti et al. | Sep 1982 | A |
4416673 | Kirchen et al. | Nov 1983 | A |
D274851 | Schmitz | Jul 1984 | S |
4543111 | Muller et al. | Sep 1985 | A |
4585466 | Syred et al. | Apr 1986 | A |
4655806 | Bowersox | Apr 1987 | A |
4657567 | Callgren et al. | Apr 1987 | A |
4673424 | Range | Jun 1987 | A |
4771580 | Male | Sep 1988 | A |
4792382 | Lorenz et al. | Dec 1988 | A |
4878927 | Margraf | Nov 1989 | A |
4894959 | Hoover | Jan 1990 | A |
4984397 | Van Leeuwen | Jan 1991 | A |
5089037 | Marsolais | Feb 1992 | A |
5185968 | Lyras | Feb 1993 | A |
5221300 | Hoogland et al. | Jun 1993 | A |
5271751 | Lagler | Dec 1993 | A |
D343706 | Gurstein | Jan 1994 | S |
5312040 | Woodward | May 1994 | A |
5319894 | Shank, Jr. | Jun 1994 | A |
D352808 | McNeil | Nov 1994 | S |
D361177 | Hoover | Aug 1995 | S |
D370490 | Zwicker | Jun 1996 | S |
5584901 | Bakharev et al. | Dec 1996 | A |
5690709 | Barnes | Nov 1997 | A |
5716260 | Griffin et al. | Feb 1998 | A |
D394526 | Strandell | May 1998 | S |
5761764 | Fiegel et al. | Jun 1998 | A |
5800246 | Tomioka | Sep 1998 | A |
5839951 | Tomioka | Nov 1998 | A |
5975996 | Settles | Nov 1999 | A |
5983840 | Riccius et al. | Nov 1999 | A |
6051054 | Ahman | Apr 2000 | A |
6195837 | Vanderlinden | Mar 2001 | B1 |
6224645 | Rydin et al. | May 2001 | B1 |
6254362 | Higuchi et al. | Jul 2001 | B1 |
6319295 | Tojner | Nov 2001 | B1 |
6431965 | Jones et al. | Aug 2002 | B1 |
6521051 | Lutich | Feb 2003 | B1 |
D476668 | Storer | Jul 2003 | S |
D482827 | Storer | Nov 2003 | S |
D482828 | Storer | Nov 2003 | S |
6833016 | Witter | Dec 2004 | B1 |