Blasting cabinet

• US 5,556,324 A
• Filed: 02/17/1995
• Issued: 09/17/1996
• Est. Priority Date: 02/17/1995
• Status: Expired due to Fees

• Current Assignee: International Surface Preparation Group Incorporated
• Original Assignee: Church & Dwight Company Incorporated
• Inventors: Shank, James D. Jr.
• Primary Examiner(s): Kisliuk, Bruce M.
• Assistant Examiner(s): Morgan, Eileen P.
• Application Number:
  US08/390,039
• Time in Patent Office: 578 Days
• Field of Search: 451/87, 451/88, 451/89, 451/90, 451/38, 451/39, 451/40
• US Class Current: 451/89
• CPC Class Codes: B24C 9/00 Appurtenances of abrasive blasting machines or devices, e.g. working chambers, arrangements for handling used abrasive material

Abstract

An abrasive blast cabinet includes a housing defining a blast chamber, a blast nozzle disposed in the blast chamber and connected to a source of an abrasive blast media for directing a flow of the blast media against a surface of an article to be cleaned, an elongated chute supported in the interior of the housing and having a first open end in fluid communication with a gas supply, a rotatable second open end in the vicinity of a work place for the article and an opening placed adjacent a window in the housing so that an operator located outside the blast chamber can direct his or her line of sight through the window and second rotatable open end and observe the article in the work place. A ventilation means, such as an exhaust fan, is provided for removing from the blast chamber blast media dispersed therein and for directing filtered air through the chute and discharging same from the rotatable second open end in a direction toward a viewing zone in the vicinity of the article and at a velocity and volume sufficient to purge blast media dispersed inside the blast cabinet away from the article being cleaned so that the operator can view the article and the cleaning action. The air removed from the interior of the blast cabinet can be filtered and recycled to the chute. A control means is provided to control the amount of filtered air recycled to the chute.

Claims

1. A blast cabinet for cleaning surfaces of articles with an abrasive blast media comprising:

a housing defining a blast chamber with an interior;

a blast nozzle disposed in said blast chamber interior and connected to a source of an abrasive blast media for directing a flow of the blast media against a surface of an article to be cleaned in said blast chamber interior whereby said blast media normally is dispersed throughout said blast chamber interior in a manner so as to obscure visual observation of a portion of the article being cleaned from outside said blast chamber;

observation means for observing the article being cleaned in said interior including a window placed in said housing and an inner viewing port situated in the vicinity of but spaced from the article to be cleaned to provide a viewing zone between said inner viewing port and the article to be cleaned, so that an operator outside said blast chamber can direct his or her line of sight through said window and said inner viewing port and observe the article being cleaned;

gas delivery means in fluid communication with said inner viewing port for directing a flow of gas into said viewing zone for purging away a sufficient amount of blast media dispersed in said viewing zone to facilitate observation through said window and said inner viewing port of at least a portion of said article being cleaned,

ventilation means to remove spent blast media and air from said interior of said housing, and,

air supply means to recycle said air removed from the interior to said gas delivery means for directing said recycled air into the interior of said blast cabinet as said flow of gas into said viewing zone,

said gas delivery means including a fixed chute place in said interior adjacent said window, said fixed chute including a first open end in communication with said air supply means, an opening adjacent said window and a second open end communicating with said inner viewing port, said inner viewing port being rotatable about said second open end of said fixed chute.

2. The blast cabinet of claim 1 wherein said inner viewing port includes an open-ended swivel chute secured to said second open end of said fixed chute.

3. The blast cabinet of claim 2 wherein said swivel chute includes a first opened end attached to said fixed chute and a second opened end facing said viewing zone, said swivel chute including a restriction immediately upstream of said second opened end whereby said restriction and said second opened end of said swivel chute comprises a venturi whereby gas passing through said swivel chute is accelerated as said gas passes through said restriction and said second opened end.

4. The blast cabinet of claim 2 further including means to reduce the amount of recycled air being passed into said viewing zone.

5. The blast cabinet of claim 4 wherein said recycled air reducing means includes means to reduce the opening of said open end of said swivel chute.

6. The blast cabinet of claim 1 including a primary filtering means for filtering said air removed from said interior to remove spent media prior to recycle into said blast cabinet.

7. The blast cabinet of claim 6 wherein said primary filtering means includes a wet scrubber wherein said air removed from said interior and containing spent media is passed through a liquid to capture said media.

8. The blast cabinet of claim 6 including a polishing filter means downstream of said primary filtering means wherein at least a portion of said filtered air is directed from said primary filtering means into said polishing filter means.

9. The blast cabinet of claim 8 wherein said polishing filter means comprises bag filters.

10. The blast cabinet of claim 8 including means to reduce the amount of said filtered air from said primary filtering means that is recycled into said viewing zone.

11. The blast cabinet of claim 10 wherein said air supply means is a duct in fluid communication with each of said primary filtering means, said polishing filter means and said gas delivery means and said ventilation means comprises a fan for directing recycled air through said duct, said recycled air reducing means being a damper assembly placed within said duct.

12. The blast cabinet of claim 11 including means to measure the gas pressure in the interior of said cabinet.

13. The blast cabinet of claim 12 further including means to measure the gas pressure in said duct adjacent said polishing filter means.

14. The blast cabinet of claim 6 including means to measure the gas pressure in the interior of said cabinet.

15. The blast cabinet of claim 1 including means to reduce the amount of recycled air being passed into said viewing zone.

16. A blast cabinet for cleaning surfaces of articles with an abrasive blast media comprising:

a housing defining a blast chamber with an interior;

a blast nozzle disposed in said blast chamber interior and connected to a source of an abrasive blast media for directing a flow of the blast media against a surface of an article to be cleaned in said blast chamber interior whereby said blast media normally is dispersed throughout said blast chamber interior in a manner so as to obscure visual observation of a portion of the article being cleaned from outside said blast chamber;

observation means for observing the article being cleaned in said interior including a window placed in said housing to provide a viewing zone between said window and the article to be cleaned, so that an operator outside said blast chamber can direct his or her line of sight through said window and observe the article being cleaned;

gas delivery means directing a flow of gas into said viewing zone for purging away a sufficient amount of blast media dispersed in said viewing zone to facilitate observation through said window of at least a portion of said article being cleaned,

ventilation means to remove spent blast media and air from said interior of said housing, and,

air supply means to recycle said air removed from the interior to said gas delivery means for directing said recycled air into the interior of said blast cabinet as said flow of gas into said viewing zone, wherein said air supply means is a duct in fluid communication with said gas delivery means, said ventilation means comprising a fan for directing recycled air through said duct, a movable damper assembly being placed within said duct to control the amount of recycled air being passed into said viewing zone.

17. The blast cabinet of claim 16 including a primary filtering means for filtering said air removed from said interior to remove spent media prior to recycle into said blast cabinet.

18. The blast cabinet of claim 17 wherein said primary filtering means includes a wet scrubber wherein said air removed from said interior and containing spent media is passed through a liquid to capture said media.

19. The blast cabinet of claim 17 including a polishing filter means downstream of said primary filtering means wherein at least a portion of said filtered air is directed from said primary filtering means into said polishing filter means.

20. The blast cabinet of claim 19 wherein said polishing filter means comprises bag filters.

21. The blast cabinet of claim 20 wherein said duct is in communication with each of said primary filtering means and said polishing filter means.

22. A blast cabinet for cleaning surfaces of articles with an abrasive blast media comprising:

a housing defining a blast chamber with an interior;

a blast nozzle disposed in said blast chamber interior and connected to a source of an abrasive blast media for directing a flow of the blast media against a surface of an article to be cleaned in said blast chamber interior whereby said blast media normally is dispersed throughout said blast chamber interior in a manner so as to obscure visual observation of a portion of the article being cleaned from outside said blast chamber;

observation means for observing the article being cleaned in said interior including a window placed in said housing and an inner viewing port situated in the vicinity of but spaced from the article to be cleaned to provide a viewing zone between said inner viewing port and the article to be cleaned, so that an operator outside said blast chamber can direct his or her line of sight through said window and said inner viewing port and observe the article being cleaned;

gas delivery means in fluid communication with said inner viewing port for directing a flow of gas into said viewing zone for purging away a sufficient amount of blast media dispersed in said viewing zone to facilitate observation through said window and said inner viewing port of at least a portion of said article being cleaned;

gas supply means communicating with said gas delivery means;

said gas delivery means including a fixed chute placed in said interior adjacent said window, said fixed chute including a first open end in communication with gas supply means, an opening adjacent said window and a second open end communicating with said inner viewing port, said inner viewing port being rotatable about said second open end of said fixed chute.