Feeder assembly for particle blast system
View Patent ↗A particle blast system includes a feeder assembly having a rotor with a plurality of pockets formed in the peripheral surface. The transport gas flowpath includes the pockets, such that substantially all transport gas flows through the pockets. The seal adjacent the peripheral surface is actuated by the transport gas pressure to urge its sealing surface against the rotor's peripheral surface. At start up, there is no substantial pressure between the seal and the rotor, reducing start up torque requirements.
1. A feeder configured to transport blast media from a source into a flow of transport gas, said feeder comprising:
a) a rotor having a circumferential surface, said rotor being rotatable about an axis of rotation;
b) a plurality of pockets disposed in said circumferential surface, each of said plurality of pockets being cyclically disposed between a first position and a second position when said rotor is rotated about said axis;
c) a transport gas flowpath, said transport gas flowpath having an inlet and an outlet, said inlet being configured to be connected to a source of transport gas;
d) a seal having a first surface contacting at least a portion of said circumferential surface, said first surface having at least one first opening and at least one second opening spaced apart from each other, said at least one first opening being in fluid communication with said inlet, said at least one second opening being in fluid communication with said outlet; and
e) said transport gas being able to flow from said at least one first opening to said at least one second opening through those of said plurality of pockets disposed between said first and second positions.
2. The feeder of claim 1 , wherein said seal includes a downstream chamber, said at least one second opening being in fluid communication with said outlet through said downstream chamber.
3. The feeder of claim 2 , wherein a wall is defined by said first surface and a second, spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas present within said downstream chamber to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
4. The feeder of claim 1 , wherein said seal includes an upstream chamber, said at least one first opening being in fluid communication with said inlet through said upstream chamber.
5. The feeder of claim 4 , wherein a wall is defined by said first surface and a second, spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas present within said upstream chamber to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
6. The feeder of claim 1 , wherein there is no substantial force between said circumferential surface and said first surface when transport gas is not flowing through said transport gas flowpath.
7. The feeder of claim 1 , wherein said first surface is urged into sealing contact with said circumferential surface when transport gas is flowing through said transport gas flowpath.
8. The feeder of claim 7 , wherein substantially all sealing force between said first surface and said circumferential surface is created by said transport gas flowing through said transport gas flowpath.
9. The feeder of claim 1 , wherein a wall is defined by said first surface and a second spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
10. The feeder of claim 1 , wherein said transport gas is able to flow from said at least one first opening to said at least one second opening only through those of said plurality of pockets disposed between said first and second positions.
11. The feeder of claim 1 , wherein a portion of said transport gas does not flow through said first and second openings.
12. The feeder of claim 1 , comprising a passageway defined at least partially by said seal, a portion of transport gas being able to flow from said at least one first opening to said at least one second opening through said first passageway.
13. The feeder of claim 1 , wherein said plurality of pockets are arranged such that said transport gas is able to flow continuously from said at least one first opening to said at least one second opening when said rotor is rotated.
14. The feeder of claim 1 , wherein said wall contacts said circumferential surface over an angle of about 180°.
15. The feeder of claim 1 , wherein said seal is of unitary construction.
16. A particle blast system comprising:
a) a source of blast media;
b) a discharge nozzle for expelling blast media from said system; and
c) a feeder configured to transport blast media from said source into a flow of transport gas, said feeder assembly comprising:
i) a rotor having a circumferential surface, said rotor being rotatable about an axis of rotation;
ii) a plurality of pockets disposed in said circumferential surface, each of said plurality of pockets being cyclically disposed between a first position and a second position when said rotor is rotated about said axis;
iii) a transport gas flowpath, said transport gas flowpath having an inlet and an outlet, said inlet being configured to be connected to a source of transport gas;
iv) a seal having a first surface contacting at least a portion of said circumferential surface, said first surface having at least one first opening and at least one second opening spaced apart from each other, said at least one first opening being in fluid communication with said inlet, said at least one second opening being in fluid communication with said outlet; and
v) said transport gas being able to flow from said at least one first opening to said at least one second opening through those of said plurality of pockets disposed between said first and second positions.
17. The particle blast system of claim 16 , wherein said seal includes a downstream chamber, said at least one second opening being in fluid communication with said outlet through said downstream chamber.
18. The particle blast system of claim 17 , wherein a wall is defined by said first surface and a second, spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas present within said downstream chamber to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
19. The particle blast system of claim 16 , wherein said seal includes an upstream chamber, said at least one first opening being in fluid communication with said inlet through said upstream chamber.
20. The particle blast system of claim 19 , wherein a wall is defined by said first surface and a second, spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas present within said upstream chamber to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
21. The particle blast system of claim 16 , wherein there is no substantial force between said circumferential surface and said first surface when transport gas is not flowing through said transport gas flowpath.
22. The particle blast system of claim 16 , wherein said first surface is urged into sealing contact with said circumferential surface when transport gas is flowing through said transport gas flowpath.
23. The particle blast system of claim 22 , wherein substantially all sealing force between said first surface and said circumferential surface is created by said transport gas flowing through said transport gas flowpath.
24. The particle blast system of claim 16 , wherein a wall is defined by said first surface and a second spaced apart surface, said wall being sufficiently flexible to transmit a substantial portion of pressure exerted against said second surface by transport gas to said circumferential surface by said first surface when transport gas is flowing through said transport gas flowpath.
25. The particle blast system of claim 16 , wherein said transport gas is able to flow from said at least one first opening to said at least one second opening only through those of said plurality of pockets disposed between said first and second positions.
26. The particle blast system of claim 16 , wherein a portion of said transport gas does not flow through said first and second openings.
27. The particle blast system of claim 16 , comprising a passageway defined at least partially by said seal, a portion of transport gas being able to flow from said at least one first opening to said at least one second opening through said first passageway.
28. The particle blast system of claim 16 , wherein said plurality of pockets are arranged such that said transport gas is able to flow continuously from said at least one first opening to said at least one second opening when said rotor is rotated.
29. The particle blast system of claim 16 , wherein said wall contacts said peripheral surface over an angle of about 180°.
30. The particle blast system of claim 16 , wherein said seal is of unitary construction.
31. A feeder configured to transport blast media from a source into a flow of transport gas, said feeder comprising:
a) a rotor having a circumferential surface, said rotor being rotatable about an axis of rotation;
b) a plurality of pockets disposed in said circumferential surface, each of said plurality of pockets being cyclically disposed between a first position and a second position when said rotor is rotated about said axis;
c) a transport gas flowpath, said transport gas flowpath having an inlet and an outlet, said inlet being configured to be connected to a source of transport gas;
d) a seal having a first surface contacting at least a portion of said circumferential surface, said first surface having at least one first opening disposed adjacent said circumferential surface, said seal defining a first passageway which is in fluid communication with said at least one first opening and with said inlet, said seal defining a second passageway which is in fluid communication with said at least one first opening and said outlet, said first passageway being in fluid communication with said second passageway at said at least one first opening.
32. The feeder of claim 31 , further comprising a wall disposed between said first and second passageways, said wall having a first edge spaced from said circumferential peripheral surface forming a gap between said wall and said circumferential surface, a portion of said flow of transport gas being able to flow through said gap from said first passageway to said second passageway.