초록 ▼

It is often desirable to operate ultraviolet (UV) water treatment systems at high fluid velocities; such as, when low UV doses are required, the UV transmittance of the water being treated is high, or when a high intensity radiation source is used. The operation of an open channel UV fluid treatment

It is often desirable to operate ultraviolet (UV) water treatment systems at high fluid velocities; such as, when low UV doses are required, the UV transmittance of the water being treated is high, or when a high intensity radiation source is used. The operation of an open channel UV fluid treatment system at high fluid velocity causes a disproportionate amount of water to pass through the relatively low intensity region above the top lamp. This results in non-uniform UV dose delivery and poor reactor performance. In one embodiment of the invention, by elevating the inlet to the irradiation zone of the fluid treatment system with respect to the outlet, the amount of water that passes above the top lamp can be minimized, improving overall system performance. The means of elevation can consist of a step or slope in the channel, or a combination of both. Depending on the magnitude of elevation, an increase in maximum velocity of approximately two times can be obtained. In practice, a means must be provided to prevent damage to the radiation sources of the elevated banks that become exposed during periods of low flow. This can consist of either a mechanism for switching off the affected lamp when low water level or high temperature is detected, or a means of lamp cooling.

대표청구항 ▼

1. A fluid treatment system comprising: at least two radiation sources disposed in an open channel irradiation zone, one of the at least two radiation sources being disposed above another of the at least two radiation sources, the irradiation zone having a fluid inlet which is elevated with respect

1. A fluid treatment system comprising: at least two radiation sources disposed in an open channel irradiation zone, one of the at least two radiation sources being disposed above another of the at least two radiation sources, the irradiation zone having a fluid inlet which is elevated with respect to a fluid outlet; and said one of the at least two radiation sources being configured to be switched off during a period of low fluid flow, while said another of the at least two radiation sources is not switched off. 2. The fluid treatment system defined in claim 1, wherein the at least two radiation sources are disposed substantially parallel to the direction of flow of fluid to the open irradiation zone. 3. The fluid treatment system defined in claim 1, wherein the at least two radiation sources are disposed substantially transverse to the direction of flow of fluid to the open irradiation zone. 4. The fluid treatment system defined in claim 1, wherein a plurality of top radiation sources are configured to be switched off during a period of low fluid flow. 5. The fluid treatment system defined in claim 1, wherein the open channel comprises a sloped surface disposed between the fluid inlet and the fluid outlet. 6. The fluid treatment system defined in claim 1, wherein the open channel comprises a plurality of sloped surfaces disposed between the fluid inlet and the fluid outlet. 7. The fluid treatment system defined in claim 6, wherein the sloped surfaces have substantially the same slope. 8. The fluid treatment system defined in claim 6, wherein the sloped surfaces have substantially different slopes. 9. The fluid treatment system defined in claim 5, wherein the sloped surface is adjustable. 10. The fluid treatment system defined in claim 5, wherein the sloped surface connects the fluid inlet and the fluid outlet. 11. The fluid treatment system defined in claim 5, wherein the sloped surface comprises a slope of at least about 0.2%. 12. The fluid treatment system defined in claim 5, wherein the sloped surface comprises a slope in the range of from about 0.2% to about 6.0%. 13. The fluid treatment system defined in claim 5, wherein the sloped surface comprises a slope in the range of from about 0.2% to about 3.0%. 14. The fluid treatment system defined in claim 5, wherein the sloped surface comprises a slope in the range of from about 0.5% to about 2.5%. 15. The fluid treatment system defined in claim 5, wherein the sloped surface comprises a slope in the range of from about 1.0% to about 2.0%. 16. The fluid treatment system defined in claim 1, wherein the at least one radiation source is substantially parallel to the sloped surface. 17. The fluid treatment system defined in claim 1, wherein the open channel comprises at least one stepped platform disposed between the fluid inlet and the fluid outlet, the at least one stepped platform comprising the at least one radiation source. 18. The fluid treatment system defined in claim 17, wherein the at least one stepped platform comprises a height in the range of from about 0.5 to about 7.0 inches. 19. The fluid treatment system defined in claim 17, wherein the at least one stepped platform comprises a height in the range of from about 0.5 to about 5.0 inches. 20. The fluid treatment system defined in claim 17, wherein the at least one stepped platform comprises a height in the range of from about 1.0 to about 4.0 inches. 21. The fluid treatment system defined in claim 17, wherein the at least one stepped platform comprises a height in the range of from about 1.0 to about 3.0 inches. 22. The fluid treatment system defined in claim 17, wherein the open channel comprises a plurality of stepped platforms disposed between the fluid inlet and the fluid outlet. 23. The fluid treatment system defined in claim 17, wherein the at least one radiation source is substantially parallel to the stepped platform. 24. The fluid treatment system defined in claim 1, wherein the open channel comprises a combination of at least one sloped surface and at least one stepped platform disposed between the fluid inlet and the fluid outlet. 25. The fluid treatment system defined in claim 1, comprising a plurality of radiation sources arranged in an array. 26. The fluid treatment system defined in claim 25, wherein the array comprises a plurality of radiation sources disposed in a radiation source module. 27. The fluid treatment system defined in claim 25, wherein the array comprises a plurality of radiation source modules. 28. The fluid treatment system defined in claim 27, wherein the plurality of radiation source modules are arranged in series to fluid flow through the system. 29. The fluid treatment system defined in claim 27, wherein the plurality of radiation source modules are arranged in parallel to fluid flow through the system. 30. The fluid treatment system defined in claim 1, wherein the open irradiation zone comprises a substantially constant width. 31. The fluid treatment system defined in claim 1, wherein the open irradiation zone comprises a variable width. 32. The fluid treatment system defined in claim 27, wherein the plurality of radiation source modules are arranged in series and in parallel to fluid flow through the system. 33. A fluid treatment system comprising: an array of radiation sources disposed in an open channel, a top one of said radiation sources being configured to be switched off during a period of low flow when a lower one of said radiation sources is switched on; and an upstream end of the open channel adjacent an upstream end of the array being elevated with respect to a downstream end of the open channel adjacent a downstream end of the array. 34. The fluid treatment system defined in claim 33, wherein the array of radiation sources is disposed substantially parallel to the direction of flow of fluid to the open irradiation zone. 35. The fluid treatment system defined in claim 33, wherein the array of radiation sources is disposed substantially transverse to the direction of flow of fluid to the open irradiation zone. 36. The fluid treatment system defined in claim 33, wherein a plurality of top radiation sources are configured to be switched off during a period of low fluid flow. 37. The fluid treatment system defined in claim 33, wherein the open channel comprises a continuous open channel. 38. The fluid treatment system defined in claim 33, wherein the open channel comprises a sloped surface disposed between the fluid inlet and the fluid outlet. 39. The fluid treatment system defined in claim 33, wherein the open channel comprises a plurality of sloped surfaces disposed between the fluid inlet and the fluid outlet. 40. The fluid treatment system defined in claim 39, wherein the sloped surfaces have substantially the same slope. 41. The fluid treatment system defined in claim 39, wherein the sloped surfaces have substantially different slopes. 42. The fluid treatment system defined in claim 38, wherein the sloped surface is adjustable. 43. The fluid treatment system defined in claim 38, wherein the sloped surface connects the fluid inlet and the fluid outlet. 44. The fluid treatment system defined in claim 38, wherein the sloped surface comprises a slope of at least about 0.2%. 45. The fluid treatment system defined in claim 38, wherein the sloped surface comprises a slope in the range of from about 0.2% to about 6.0%. 46. The fluid treatment system defined in claim 38, wherein the sloped surface comprises a slope in the range of from about 0.2% to about 3.0%. 47. The fluid treatment system defined in claim 38, wherein the sloped surface comprises a slope in the range of from about 0.5% to about 2.5%. 48. The fluid treatment system defined in claim 38, wherein the sloped surface comprises a slope in the range of from about 1.0% to about 2.0%. 49. The fluid treatment system defined in claim 38, wherein the radiation sources are substantially parallel to the sloped surface. 50. The fluid treatme nt system defined in claim 33, wherein the open channel comprises at least one stepped platform disposed between the fluid inlet and the fluid outlet, the at least one stepped platform comprising the array of radiation sources. 51. The fluid treatment system defined in claim 50, wherein the at least one stepped platform comprises a height in the range of from about 0.5 to about 7.0 inches. 52. The fluid treatment system defined in claim 50, wherein the at least one stepped platform comprises a height in the range of from about 0.5 to about 5.0 inches. 53. The fluid treatment system defined in claim 50, wherein the at least one stepped platform comprises a height in the range of from about 1.0 to about 4.0 inches. 54. The fluid treatment system defined in claim 50, wherein the at least one stepped platform comprises a height in the range of from about 1.0 to about 3.0 inches. 55. The fluid treatment system defined in claim 33, wherein the open channel comprises at least one stepped platform disposed between the fluid inlet and the fluid outlet, the at least one stepped platform comprising the array. 56. The fluid treatment system defined in claim 33, wherein the open channel comprises at plurality of stepped platforms disposed between the fluid inlet and the fluid outlet. 57. The fluid treatment system defined in claim 56, wherein each stepped platform comprises an array of radiation sources. 58. The fluid treatment system defined in claim 33, wherein the open channel comprises a combination of at least one sloped surface and at least one stepped platform. 59. The fluid treatment system defined in claim 38, wherein the at least one radiation source is substantially parallel to the sloped surface. 60. The fluid treatment system defined in claim 33, wherein the array comprises a plurality of radiation sources disposed in a radiation source module. 61. The fluid treatment system defined in claim 60, wherein the array comprises a plurality of radiation source modules. 62. The fluid treatment system defined in claim 61, wherein the plurality of radiation source modules are arranged in series to fluid flow through the system. 63. The fluid treatment system defined in claim 33, wherein the open channel comprises a substantially constant width. 64. The fluid treatment system defined in claim 33, wherein the open channel comprises a variable width. 65. The fluid treatment system defined in claim 61, wherein the plurality of radiation source modules are arranged in parallel in fluid flow through the system. 66. The fluid treatment system defined in claim 61, wherein the plurality of radiation source modules are arranged in series and in parallel to fluid flow through the system. 67. A fluid treatment system comprising: a plurality of serially disposed open channel irradiation zones which are elevated with respect to one another thereby substantially normalizing the fluid level with respect to the top of each irradiation zone; and two radiation sources disposed in at least one of said plurality of serially disposed open channel irradiation zones, a top radiation source being configured to be switched off during a period of low flow while a lower radiation source is not switched off. 68. A fluid treatment system comprising: a first irradiation zone and a second irradiation zone disposed at different heights with respect to one another in an open channel such that the fluid level is substantially normalized with respect to the top of each of the first irradiation zone and the second irradiation zone; and two radiation sources disposed in said first irradiation zone, a top radiation source being configured to be switched off during a period of low flow while a lower radiation source remains on. 69. The fluid treatment system defined in claim 68, wherein the first irradiation zone is stepped with respect to the second irradiation zone. 70. The fluid treatment system defined in claim 68, wherein the first irradiation zone is sloped with re spect to the second irradiation zone. 71. A fluid treatment system comprising a canal for receiving a fluid to be treated, a first upstream irradiation zone and a second downstream irradiation zone which is elevated with respect to the first upstream irradiation zone. 72. The fluid treatment system defined in claim 71, wherein the first irradiation zone is stepped with respect to the second irradiation zone. 73. The fluid treatment system defined in claim 71, wherein the first irradiation zone is sloped with respect to the second irradiation zone.