Gas compression apparatus and method with noise attenuation
A gas compression method and method according to which an impeller rotates to flow fluid through a casing, and a plate is disposed in a wall of the casing. At least one series of cells are formed in the plate to form an array of acoustic resonators to attenuate acoustic energy generated by the impeller.
1. A gas compression apparatus comprising a casing having an inlet for receiving gas; an impeller disposed in the casing for receiving gas from the inlet and compressing the gas; a plate disposed in a wall of the casing defining a diffuser channel in the casing; and at least one series of cells formed in the plate to form an array of resonators to attenuate acoustic energy generated by the impeller, the depth of the cells varying along the plate.
2. The apparatus of claim 1 wherein the plate is annular and wherein the depth of each cell varies from the radially outward portion of the plate to the radially inward portion.
3. The apparatus of claim 1 wherein a first series of cells extends from one surface of the plate, and a second series of cells extends from the opposite surface of the plate, the size of each cell of the first series of cells being greater than the size of each cell in the second series of cells.
4. The apparatus of claim 3 wherein the cells in the second series of cells extend to the cells in the first series of cells.
5. The apparatus of claim 3 wherein the cells are in the form of bores formed in the plate, and wherein the diameter of each bore of the first series of cells is greater than the diameter of the bore of the second series of cells.
6. The apparatus of claim 5 wherein one cell of the first series of cells is associated with a plurality of cells of the second series of cells.
7. The apparatus of claim 5 wherein the plate is annular and wherein the depth of each cell varies from the radially outward portion of the plate to the radially inward portion.
8. The apparatus of claim 7 wherein the depth of each cell of the first series of cells decreases from the radially outward portion of the plate to the radially inward portion.
9. The apparatus of claim 8 wherein the depth of the each cell of the second series of cells increases from the radially outward portion of the plate to the radially inward portion.
10. The apparatus of claim 7 wherein the thickness of the plate increases from the radially outward portion of the plate to the radially inward portion.
11. The apparatus of claim 10 wherein the depth of the each cell of the first and second series of cells increases from the radially outward portion of the plate to the radially inward portion.
12. The apparatus of claim 3 wherein the first series of cells extends from the surface of the plate facing the diffuser channel.
13. The apparatus of claim 1 wherein a volute is formed in the casing in communication with the diffuser channel for receiving the pressurized gas from the diffuser channel.
14. The apparatus of claim 1 wherein the number and size of the cells are constructed and arranged to attenuate the dominant noise component of acoustic energy associated with the apparatus.
15. The apparatus of claim 1 wherein the resonators are either Helmholtz resonators or quarter-wave resonators.
16. A gas compression method comprising introducing gas into an inlet of a casing; compressing the gas in the casing; passing the compressed gas to a volute in the casing for discharging the compressed gas; and forming at least one series of cells formed in a plate in the casing to form an array of resonators to attenuate acoustic energy generated during the step of compressing, the depth of the cells varying along the plate.
17. The method of claim 16 wherein the plate is annular and wherein the depth of each cell varies from the radially outward portion of the plate to the radially inward portion.
18. The method of claim 16 wherein a first series of cells extends from one surface of the plate, and a second series of cells extends from the opposite surface of the plate to the first series of cells, the size of each cell of the first series of cells being greater than the size of each cell in the second series of cells.
19. The method of claim 18 wherein the cells in the second series of cells extend to the cells in the first series of cells.
20. The method of claim 18 wherein the cells are in the form of bores formed in the plate, and wherein the diameter of each bore of the first series of cells is greater than the diameter of the bore of the second series of cells.
21. The method of claim 20 wherein one cell of the first series of cells is associated with a plurality of cells of the second series of cells.
22. The method of claim 18 wherein the plate is annular and wherein the depth of each cell varies from the radially outward portion of the plate to the radially inward portion.
23. The method of claim 22 wherein the depth of each cell of the first series of cells decreases from the radially outward portion of the plate to the radially inward portion.
24. The method of claim 23 wherein the depth of each cell of the second series of cells increases from the radially outward portion of the plate to the radially inward portion.
25. The method of claim 22 wherein the thickness of the plate increases from the radially outward portion of the plate to the radially inward portion.
26. The method of claim 25 wherein the depth of each cell of the first and second series of cells increases from the radially outward portion of the plate to the radially inward portion.
27. The method of claim 16 wherein the number and size of the cells are constructed and arranged to attenuate the dominant noise component of acoustic energy associated with the method.
28. The method of claim 16 the resonators are either Helmholtz resonators or quarter-wave resonators.