Claims
- 1. A fluid treatment element comprising:
a fluid treatment pack having first and second lengthwise end faces and including a fluid treatment layer having first and second sides and a sealing strip extending for less than a length of the fluid treatment pack on the first side of the fluid treatment layer and preventing fluid from flowing through the first lengthwise end face into the fluid treatment pack on the first side of the fluid treatment layer.
- 2. A fluid treatment element as claimed in claim 1 wherein the fluid treatment pack comprises a first drainage layer on the first side of the fluid treatment layer, and the sealing strip prevents fluid from flowing into the first drainage layer through the first lengthwise end face of the fluid treatment pack.
- 3. A fluid treatment element as claimed in claim 1 wherein the first drainage layer comprises a mesh.
- 4. A fluid treatment element as claimed in claim 2 wherein the sealing strip overlaps the first drainage layer in a lengthwise direction of the fluid treatment pack.
- 5. A fluid treatment element as claimed in claim 2 wherein fluid can flow through the first lengthwise end face on the second side of the fluid treatment layer.
- 6. A fluid treatment element as claimed in claim 2 wherein the fluid treatment pack includes a second drainage layer on the second side of the fluid treatment layer, and fluid can flow through the first lengthwise end face into the second drainage layer.
- 7. A fluid treatment element as claimed in claim 1 wherein the fluid treatment pack has axially extending pleats.
- 8. A fluid treatment element as claimed in claim 1 wherein the sealing strip comprises a closed cell foam.
- 9. A fluid treatment element as claimed in claim 1 wherein the sealing strip has a hardness of about Shore A20 or softer.
- 10. A fluid treatment element as claimed in claim 1 wherein the fluid treatment pack is spirally wound.
- 11. A fluid treatment element as claimed in claim 1 wherein the fluid treatment pack is cylindrical and the sealing strip is on a radially outer side of the fluid treatment layer.
- 12. A fluid treatment element as claimed in claim 1 wherein the fluid treatment pack is cylindrical and the sealing strip is on a radially inner side of the fluid treatment layer.
- 13. A fluid treatment element comprising:
a hollow fluid treatment pack containing a fluid treatment medium; and a core surrounded by the fluid treatment pack and having a blind region in which fluid cannot flow between an interior of the core and the fluid treatment pack extending continuously over at least fifty percent of a length of the fluid treatment pack.
- 14. A fluid treatment element as claimed in claim 13 wherein the blind region extends over at least seventy-five percent of the length of the fluid treatment pack.
- 15. A fluid treatment element as claimed in claim 13 wherein the blind region extends over at least ninety percent of the length of the fluid treatment pack.
- 16. A fluid treatment element as claimed in claim 13 wherein the core includes a region in which fluid can flow between the interior of the core and the fluid treatment pack adjoining a lengthwise end of the blind region.
- 17. A fluid treatment element as claimed in claim 13 including a region through which fluid can flow between an interior of the core and the fluid treatment pack adjoining each lengthwise end of the blind region.
- 18. A fluid treatment element as claimed in claim 13 wherein the blind region has an outer surface contacting an inner periphery of the fluid treatment pack and preventing fluid flow between the outer surface and the inner periphery of the fluid treatment pack.
- 19. A fluid treatment element as claimed in claim 18 wherein the outer surface comprises a resilient material.
- 20. A fluid treatment element as claimed in claim 19 wherein the outer surface comprises a closed cell foam.
- 21. A fluid treatment element as claimed in claim 13 wherein the fluid treatment pack has axially extending pleats.
- 22. A fluid treatment element as claimed in claim 13 wherein the fluid treatment pack has a lengthwise end face through which fluid can flow.
- 23. A fluid treatment element adapted for cross flow filtration comprising a fluid treatment pack having a fluid treatment layer, a first mesh layer disposed on a first side of the fluid treatment layer, and a second mesh layer disposed on a second side of the fluid treatment layer, the fluid treatment element defining a flow path for a process fluid to be treated passing in a lengthwise direction of the fluid treatment element inside the first mesh layer and a flow path for permeate passing through the second mesh layer.
- 24. A fluid treatment element as claimed in claim 23 wherein one of the mesh layers comprises a nonwoven polymeric mesh.
- 25. A fluid treatment element as claimed in claim 23 wherein each mesh layer comprises a nonwoven polymeric mesh.
- 26. A fluid treatment element as claimed in claim 23 wherein the fluid treatment pack has axially extending pleats.
- 27. A fluid treatment element as claimed in claim 26 wherein the fluid treatment pack includes a plurality of pleats each having a radially outer end displaced in a circumferential direction of the fluid treatment pack with respect to a radially inner end of the pleat.
- 28. A fluid treatment element as claimed in claim 23 wherein the fluid treatment pack has a first lengthwise end face through which fluid can flow into the first mesh layer but not into the second mesh layer.
- 29. A fluid treatment element as claimed in claim 23 wherein the first mesh layer has first and second sets of intersecting strands extending diagonally with respect to the lengthwise direction of the fluid treatment element.
- 30. A fluid treatment element as claimed in claim 29 wherein the first mesh layer comprises a diamond mesh.
- 31. A fluid treatment assembly comprising:
a housing having a process fluid chamber, a permeate chamber, and a retentate chamber; and a cylindrical fluid treatment element disposed in the housing and comprising a pleated fluid treatment layer having a radially inner side and a radially outer side, the fluid treatment element defining a first flow path passing through the fluid treatment element in a lengthwise direction of the fluid treatment element along the radially inner side of the fluid treatment layer between the process fluid chamber and the retentate chamber, and a second flow path passing through the fluid treatment layer between the process fluid chamber and the permeate chamber.
- 32. An assembly as claimed in claim 31 wherein the fluid treatment element comprises a pleated fluid treatment pack containing the fluid treatment layer, and the first flow path passes through a lengthwise end face of the fluid treatment pack.
- 33. An assembly as claimed in claim 31 wherein a portion of the first flow path passes along a hollow center of the fluid treatment element.
- 34. An assembly as claimed in claim 31 wherein the fluid treatment element includes a core surrounded by the fluid treatment layer and having a blind region in which fluid can not flow between an interior and exterior of the core extending continuously over at least fifty percent of a length of the fluid treatment element, the first flow path extending along an exterior of the blind region.
- 35. A fluid treatment element comprising:
a fluid treatment pack through which fluid can flow in a lengthwise direction of the fluid treatment pack and surrounding a hollow center of the fluid treatment element; and a flow restriction disposed in the hollow center for partially restricting fluid flow in the lengthwise direction of the fluid treatment element through the hollow center.
- 36. A fluid treatment element as claimed in claim 35 wherein the flow restriction comprises an orifice.
- 37. A fluid treatment element as claimed in claim 35 including a hollow core disposed in the hollow center and having a blind region in which fluid cannot flow between an interior of the core and the fluid treatment pack, the flow restriction restricting flow through the blind region in a lengthwise direction of the core.
- 38. A fluid treatment element as claimed in claim 37 wherein the core includes a first perforated region at a first lengthwise end of the blind region and a second perforated region at a second lengthwise end of the blind region, and the flow restriction is disposed in the core at the first lengthwise end of the blind region.
- 39. A fluid treatment element as claimed in claim 38 including a second flow restriction disposed in the core at the second lengthwise end of the blind region.
- 40. A fluid treatment element as claimed in claim 39 wherein the first and second flow restrictions each comprise an orifice of the same size.
- 41. A fluid treatment arrangement comprising:
a first fluid treatment element having a hollow center and first and second lengthwise ends and including a fluid treatment pack surrounding the hollow center and containing a fluid treatment medium, the first fluid treatment element defining a first flow path between the first and second ends through the fluid treatment pack and a second flow path through the hollow center between the first and second ends and bypassing the fluid treatment pack, and a flow restriction disposed in the hollow center for partially restricting fluid flow in a lengthwise direction of the fluid treatment element through the hollow center; and a second fluid treatment element connected in series with the first fluid treatment element so as to receive fluid passing along the first and second flow paths of the first fluid treatment element and defining a first flow path passing through a fluid treatment pack of the second fluid treatment element.
- 42. A fluid treatment arrangement as claimed in claim 41 wherein the flow restriction comprises an orifice.
- 43. A fluid treatment arrangement as claimed in claim 41 wherein the second fluid treatment element has a hollow center surrounded by the fluid treatment pack of the second fluid treatment element and defines a second flow path passing through the hollow center of the second fluid treatment element and bypassing the fluid treatment pack of the second fluid treatment element, the second fluid treatment element including a flow restriction disposed in the hollow center of the second fluid treatment element for partially restricting fluid flow in a lengthwise direction of the second fluid treatment element through its hollow center.
- 44. A fluid treatment arrangement as claimed in claim 43 including a third fluid treatment element connected in series with the second fluid treatment element so as to receive fluid passing along the first and second flow paths of the second fluid treatment element and defining a flow path passing through a fluid treatment pack of the third fluid treatment element.
- 45. A fluid treatment arrangement as claimed in claim 41 wherein the first fluid treatment element includes a hollow core surrounded by the fluid treatment pack of the first fluid treatment element, and the flow restriction partially restricts fluid flow in a lengthwise direction of the first fluid treatment element through the core.
- 46. A fluid treatment element including a fluid treatment pack containing a fluid treatment medium and a bypass passage surrounding the fluid treatment pack and enabling fluid to flow in a lengthwise direction of the fluid treatment element while bypassing the fluid treatment pack, the bypass passage having an inlet at a first lengthwise end of the fluid treatment element and an outlet at a second lengthwise end of the fluid treatment element, an interior of the bypass passage being isolated from the fluid treatment pack between the inlet and outlet.
- 47. A fluid treatment element as claimed in claim 46 wherein the fluid treatment element comprises a first tube surrounding the fluid treatment pack and a second tube surrounding the first tube, the bypass passage comprising a space between the first and second tubes.
- 48. A fluid treatment arrangement comprising:
a first fluid treatment element including a fluid treatment pack containing a fluid treatment medium, a first member surrounding the fluid treatment pack, and a second member surrounding the first member and defining a bypass passage between the first and second members through which fluid can flow in a lengthwise direction of the first fluid treatment element while bypassing the fluid treatment pack; and a second fluid treatment element connected in series with the first fluid treatment element so as to receive fluid passing through the fluid treatment pack and the bypass passage of the first fluid treatment element.
- 49. An arrangement as claimed in claim 48 wherein the first fluid treatment element defines a flow path passing through the fluid treatment pack between first and second lengthwise ends of the first fluid treatment element without passing through the fluid treatment medium.
- 50. A fluid treatment arrangement comprising:
a cylindrical fluid treatment element comprising a hydrophobic gas pore membrane having first and second sides, the fluid treatment element defining a first flow path in a lengthwise direction of the fluid treatment element on the first side of the membrane and a second flow path in a lengthwise direction of the fluid treatment element on the second side of the membrane; a ClO2 generator fluidly connected to the first flow path for supplying an aqueous solution containing dissolved ClO2 to the fluid treatment element; and a source of a fluid to receive ClO2 fluidly connected to the second flow path.
- 51. An arrangement as claimed in claim 50 wherein the ClO2 generator is an electrolytic ClO2 generator.
- 52. An arrangement as claimed in claim 50 wherein the fluid to receive ClO2 comprises water.
- 53. An arrangement as claimed in claim 50 wherein the first and second flow paths pass through the fluid treatment element in opposite lengthwise directions of the fluid treatment element.
- 54. An arrangement as claimed in claim 50 including a first mesh layer on a first side of the membrane and a second mesh layer on a second side of the membrane, the first and second flow paths passing within the first and second mesh layers, respectively, in the lengthwise direction of the fluid treatment element.
- 55. An arrangement as claimed in claim 54 wherein each of the mesh layers comprises a nonwoven polymeric mesh.
- 56. An arrangement as claimed in claim 50 wherein the fluid treatment element has axially extending pleats.
- 57. A fluid treatment assembly comprising:
a housing which has first through fourth tube sheets and which is divided by the tube sheets in a lengthwise direction of the housing into a first chamber, a second chamber located between the first and second tube sheets and separated from the first chamber by the first tube sheet, a third chamber located between the second and third tube sheets, a fourth chamber located between the third and fourth tube sheets, and a fifth chamber separated from the fourth chamber by the fourth tube sheet, each of the chambers having a fluid port communicating between the chamber and an exterior of the housing; at least one fluid treatment element disposed in the second chamber and fluidly communicating with the first and third chambers through openings in the first and second tube sheets; and at least one fluid treatment element disposed in the fourth chamber and fluidly communicating with the third and fifth chambers through openings in the third and fourth tube sheets.
- 58. A fluid treatment assembly as claimed in claim 57 wherein each of the fluid treatment elements comprises a pleated fluid treatment element.
- 59. A fluid treatment assembly as claimed in claim 57 wherein fluid can flow between an interior of each of the fluid treatment elements in the second chamber and the interior of the second chamber only at a location on the fluid treatment element closer to the first tube sheet than to the second tube sheet.
- 60. A fluid treatment assembly as claimed in claim 59 wherein fluid can flow between an interior of each of the fluid treatment elements in the fourth chamber and the interior of the fourth chamber only at a location on the fluid treatment element closer to the fourth tube sheet than to the third tube sheet.
- 61. A fluid treatment element comprising:
a fluid treatment pack having axially extending pleats and comprising a pleated composite including a fluid treatment layer, a first drainage layer on a first side of the fluid treatment layer, and a second drainage layer on a second side of the fluid treatment layer; a first open end cap sealed to a first lengthwise end of the fluid treatment pack and a second open end cap sealed to a second lengthwise end of the fluid treatment pack; and a core surrounded by the fluid treatment pack and having first and second open ends, a first perforated region adjoining the first open end of the core and having a blind inner end, and a second perforated region adjoining the second open end of the core and having a blind inner end, fluid being able to flow between the perforated regions only on an exterior of the core.
- 62. A fluid treatment element as claimed in claim 61 wherein each of the drainage layers comprises a mesh.
- 63. A fluid treatment element as claimed in claim 62 wherein each of the drainage layers comprises a nonwoven polymeric mesh.
- 64. A fluid treatment element as claimed in claim 61 wherein the fluid treatment pack has a plurality of pleats each having a radially inner end and a radially outer end displaced with respect to the radially inner end in a circumferential direction of the fluid treatment pack.
- 65. A fluid treatment element as claimed in claim 64 wherein the fluid treatment pack has a plurality of pleats each having first and second legs, the first leg being pressed against the second leg of the same pleat and against the second leg of an adjoining pleat over a continuous region extending for a substantial portion of the height of the first leg and over at least fifty percent of an axial length of the fluid treatment pack.
- 66. A fluid treatment element comprising:
a pleated fluid treatment pack containing a fluid treatment layer having a radially inner side and a radially outer side and a hollow center, a first lengthwise end into which a process fluid can flow into the radially outer side of the fluid treatment layer but not into the radially inner side of the fluid treatment layer, and a second lengthwise end having a lengthwise end face which is sealed to prevent fluid from flowing through the lengthwise end face; and a tube surrounding the fluid treatment pack and preventing fluid from flowing in a radial direction of the fluid treatment element between the fluid treatment pack and an exterior of the fluid treatment element except in a region in a vicinity of the second lengthwise end of the fluid treatment pack.
- 67. A fluid treatment element as claimed in claim 66 wherein the tube contains at least one opening in the region in the vicinity of the second lengthwise end.
- 68. A fluid treatment element as claimed in claim 67 wherein a total flow area of the at least one opening is about equal to a cross-sectional area through which fluid can flow into the fluid treatment pack at the first lengthwise end.
- 69. A fluid treatment element as claimed in claim 66 including a first end cap at the first lengthwise end of the fluid treatment pack and a second end cap at the second lengthwise end of the fluid treatment pack, the tube extending between the first and second end caps.
- 70. A fluid treatment element as claimed in claim 69 wherein each of the end caps is adapted to be connected to a tube sheet.
- 71. A fluid treatment element as claimed in claim 66 including a perforated core disposed in the hollow center of the fluid treatment pack, the core having a closed end at the first lengthwise end of the fluid treatment pack and an open end at the second lengthwise end of the fluid treatment pack.
- 72. A fluid treatment element comprising:
a hollow pleated fluid treatment pack having two lengthwise end faces through which fluid can flow into the fluid treatment pack; a fluid impervious member surrounding the fluid treatment pack for preventing fluid from flowing into the fluid treatment pack from an exterior of the fluid treatment element between the lengthwise end faces; a sealing member for sealing a first lengthwise end of the fluid treatment element to a tube sheet of a fluid treatment housing; a tube communicating with the hollow center of the fluid treatment pack and extending outwards from one of the lengthwise end faces of the fluid treatment pack; and a sealing member for sealing the tube to a tube sheet of a fluid treatment housing.
- 73. A fluid treatment assembly comprising:
a fluid treatment housing including first and second tube sheets, a first chamber adjoining the first tube sheet, a second chamber between the first and second tube sheets and separated from the first chamber by the first tube sheet, and a third chamber adjoining the second tube sheet and separated from the second chamber by the second tube sheet; and a fluid treatment element disposed in the second chamber and comprising a hollow pleated fluid treatment pack having first and second lengthwise end faces through which fluid can flow, a first lengthwise end connected to the first tube sheet, a tube communicating with a hollow center of the fluid treatment pack and connected to the second tube sheet, and a fluid impervious member surrounding the fluid treatment pack for preventing fluid from flowing into the fluid treatment pack from the second chamber except through the second lengthwise end face of the fluid treatment pack.
- 74. A fluid treatment assembly comprising:
a fluid treatment element having a hollow center and a pleated fluid treatment pack surrounding the hollow center, a blind end cap connected to a first lengthwise end of the fluid treatment pack, and an open end cap connected to a second lengthwise end of the fluid treatment pack; and a housing containing the fluid treatment element and including a first fluid port opening onto a region of the housing on an exterior of the fluid treatment element, a second fluid port opening onto a region of the housing on an exterior of the fluid treatment element, and a third fluid port communicating with the hollow center of the fluid treatment pack, the fluid treatment element being disposed between the first and second fluid ports, the housing surrounding the fluid treatment element sufficiently closely that a flow path between the first and second fluid ports passing through the fluid treatment pack provides lower resistance to flow than a flow path between the first and second fluid ports passing between the fluid treatment pack and the housing.
- 75. A fluid treatment element having first and second open ends through which fluid can flow and comprising a pleated fluid treatment pack disposed between the open ends of the fluid treatment element and a fluid impervious member surrounding the fluid treatment pack and preventing fluid from flowing into the fluid treatment pack from an exterior thereof except in a lengthwise midportion of the fluid treatment element.
- 76. A fluid treatment element as claimed in claim 75 wherein the fluid treatment pack has first and second lengthwise end faces through which fluid can flow into the fluid treatment pack.
- 77. A fluid treatment element as claimed in claim 75 wherein the impervious member comprises a tube surrounding the fluid treatment pack and having at least one opening at its lengthwise midportion through which fluid can flow.
- 78. A fluid treatment element as claimed in claim 77 wherein the tube fits sufficiently tightly around the fluid treatment pack that a flow path between either open end of the fluid treatment element and the at least one opening in the tube passing through the fluid treatment pack provides less resistance to flow than a flow path between either end of the fluid treatment element and the at least one opening in the tube passing between the fluid treatment pack and the tube.
- 79. A fluid treatment method comprising:
introducing a process fluid into a cylindrical fluid treatment pack comprising a fluid treatment layer having a radially inner side and a radially outer side; passing the process fluid in a lengthwise direction of the fluid treatment pack along the radially inner side of the fluid treatment layer to produce a fluid shear force on the radially inner side of the fluid treatment layer; passing a portion of the process fluid though the fluid treatment layer to the radially outer side of the fluid treatment layer to form a permeate; and discharging the permeate and the process fluid which does not pass through the fluid treatment layer from the fluid treatment element.
- 80. A method as claimed in claim 79 including introducing the process fluid through a lengthwise end face of the fluid treatment pack.
- 81. A method as claimed in claim 79 including discharging the process fluid which does not pass through the fluid treatment layer through a lengthwise end face of the fluid treatment pack.
- 82. A method as claimed in claim 79 including introducing the process fluid into a hollow center of the fluid treatment element and passing the process fluid from the hollow center into the fluid treatment pack.
- 83. A method as claimed in claim 79 wherein the fluid treatment pack includes a first drainage layer on the radially inner side of the fluid treatment layer, and passing the process fluid in the lengthwise direction of the fluid treatment pack comprises passing the process fluid through the first drainage layer.
- 84. A fluid treatment method comprising:
introducing a process fluid into a first mesh layer on a first side of a fluid treatment layer at a first lengthwise end of a fluid treatment element; passing the process fluid in a lengthwise direction of the fluid treatment pack within the first mesh layer toward a second lengthwise end of the fluid treatment element to generate a fluid shear force on the first side of the fluid treatment layer; and passing a portion of the process fluid through the fluid treatment layer into a second mesh layer on a second side of the fluid treatment layer.
- 85. A method as claimed in claim 84 including discharging the process fluid which does not pass through the fluid treatment layer from a second lengthwise end of the fluid treatment element.
- 86. A method as claimed in claim 84 wherein the fluid treatment element includes a fluid treatment pack containing the fluid treatment layer, the method including introducing the process fluid into the first mesh layer through a first lengthwise end face of the fluid treatment pack.
- 87. A method as claimed in claim 86 including discharging the process fluid which is not passed through the fluid treatment layer from the fluid treatment pack through a second lengthwise end face of the fluid treatment pack.
- 88. A fluid treatment method comprising:
introducing a fluid through a lengthwise end face of a fluid treatment pack into a first mesh layer on a first side of a fluid treatment layer of the fluid treatment pack; and passing at least a portion of the fluid through the fluid treatment layer into a second mesh layer on a second side of the fluid treatment layer.
- 89. A method as claimed in claim 88 including passing all of the fluid through the fluid treatment layer into the second mesh layer.
- 90. A fluid treatment method comprising:
introducing a process fluid into a fluid treatment element having a fluid treatment layer and a drainage mesh disposed on one side of the fluid treatment layer, the drainage mesh having first and second sets of strands extending diagonally with respect to a lengthwise direction of the fluid treatment element; passing the process fluid through the drainage mesh in a lengthwise direction of the fluid treatment element to produce a fluid shear force along a surface of the fluid treatment layer; and passing a portion of the process fluid through the fluid treatment layer to form a permeate.
- 91. A method as claimed in claim 90 wherein the fluid treatment element has axially extending pleats.
- 92. A method as claimed in claim 90 wherein the drainage mesh comprises a nonwoven polymeric mesh.
- 93. A method as claimed in claim 92 wherein the drainage mesh comprises a diamond mesh.
- 94. A fluid treatment method comprising:
introducing a fluid into a first fluid treatment element at a first lengthwise end thereof; passing a first portion of the fluid along a first flow path through a fluid treatment pack of the first fluid treatment element and passing a second portion of the fluid along a second flow path through the fluid treatment element bypassing the fluid treatment pack; combining fluid which has passed along the first and second flow paths at a second lengthwise end of the fluid treatment element; and discharging the combined fluid from the first fluid treatment element.
- 95. A method as claimed in claim 94 including introducing the combined fluid discharged from the first fluid treatment element into a second fluid treatment element connected in series with the first fluid treatment element.
- 96. A method as claimed in claim 94 wherein the second flow path passes along a hollow center of the first fluid treatment element surrounded by the fluid treatment pack.
- 97. A method as claimed in claim 96 wherein the second flow path passes through a flow restriction.
- 98. A method as claimed in claim 97 wherein the second flow path passes through an orifice.
- 99. A method as claimed in claim 94 wherein the second flow path passes along a passage surrounding the fluid treatment pack.
- 100. A method as claimed in claim 95 including:
introducing the combined fluid discharged from the first fluid treatment element into a first lengthwise end of the second fluid treatment element; passing a first portion of the fluid introduced into the second fluid treatment element along a first flow path through a fluid treatment pack of the second fluid treatment element and a second portion of the fluid introduced into the second fluid element along a second flow path through the second fluid treatment element bypassing the fluid treatment pack of the second fluid treatment element; combining fluid which has passed along the first and second flow paths of the second fluid treatment element and discharging the combined fluid from the second fluid treatment element.
- 101. A method as claimed in claim 100 including introducing the fluid discharged from the second fluid treatment element into a third fluid treatment element connected in series with the second fluid treatment element.
- 102. A method of fluid treatment comprising:
passing a first fluid stream through a pleated fluid treatment element in a lengthwise direction of the fluid treatment element on a first side of a fluid treatment layer of the fluid treatment element; passing a second fluid stream through the fluid treatment element in a lengthwise direction of the fluid treatment element on a second side of the fluid treatment layer; and transferring material across the fluid treatment layer between the two fluid streams.
- 103. A method as claimed in claim 102 including passing the two fluid streams in opposite lengthwise directions through the fluid treatment element.
- 104. A method as claimed in claim 102 wherein the fluid treatment layer is a hydrophobic gas pore membrane, the method including transferring dissolved gas between the two fluid streams across the membrane.
- 105. A method as claimed in claim 104 including transferring ClO2 from the first fluid stream to the second fluid stream through the membrane.
- 106. A method as claimed in claim 105 including supplying the first fluid stream to the fluid treatment element from a ClO2 generator.
- 107. A method as claimed in claim 106 including supplying the first fluid stream to the fluid treatment element from an electrolytic ClO2 generator.
- 108. A method as claimed in claim 105 including disinfecting the second fluid stream with ClO2 transferred from the first fluid stream.
- 109. A method as claimed in claim 108 including using the disinfected second fluid stream as drinking water.
- 110. A method as claimed in claim 102 including creating turbulent flow of the first and second fluid streams in the fluid treatment element.
- 111. A method as claimed in claim 102 including passing the first and second fluid streams in the lengthwise direction of the fluid treatment element through first and second mesh layers, respectively, disposed on opposite sides of the fluid treatment layer.
- 112. A method as claimed in claim 102 wherein the fluid treatment element has a plurality of pleats each having first and second legs, the first leg being pressed against the second leg of the same pleat and against the second leg of an adjoining pleat over a continuous region extending for a substantial portion of the height of the first leg and over at least fifty percent of an axial length of the fluid treatment element.
- 113. A method as claimed in claim 102 including introducing the first fluid stream into the fluid treatment element at multiple locations spaced in a circumferential direction of the fluid treatment element along an outer periphery of the fluid treatment element and
removing the first fluid stream from the fluid treatment element at multiple locations spaced in a circumferential direction of the fluid treatment element along the outer periphery of the fluid treatment element.
- 114. A method as claimed in claim 113 wherein the fluid treatment element includes a hollow pleated fluid treatment pack containing the fluid treatment layer, the method including introducing the second fluid stream into the fluid treatment pack at multiple locations spaced in the circumferential direction of the fluid treatment element along an inner periphery of the fluid treatment pack and removing the second fluid stream from the fluid treatment element at multiple locations spaced in the circumferential direction of the fluid treatment element along the inner periphery of the fluid treatment pack.
- 115. A method as claimed in claim 113 including introducing the first fluid stream into the fluid treatment element through a first manifold surrounding the fluid treatment element and removing the first fluid stream from the fluid treatment element through a second manifold surrounding the fluid treatment element.
- 116. A fluid treatment method comprising passing a fluid through a fluid treatment layer from a first side to a second side of the fluid treatment layer to treat the fluid and then cleaning the fluid treatment layer by passing a liquid and a gas along the first side of the fluid treatment layer in a lengthwise direction of the fluid treatment element.
- 117. A method as claimed in claim 116 including removing particles from the fluid when passing the fluid through the fluid treatment layer, wherein cleaning the fluid treatment layer comprises removing particles from the fluid treatment layer with the liquid and gas.
- 118. A method as claimed in claim 116 including maintaining a fluid pressure on the second side of the fluid treatment layer to prevent the liquid and gas from passing through the fluid treatment layer from the first side to the second side.
- 119. A method as claimed in claim 116 including passing the liquid and gas along the first side of the fluid treatment layer sequentially.
- 120. A method as claimed in claim 116 including passing the liquid and gas along the first side of the fluid treatment layer simultaneously.
- 121. A method as claimed in claim 116 including passing the gas along the first side of the fluid treatment layer at a rate of at least about 0.04 scfm per square foot of area of the first side of the fluid treatment layer.
- 122. A method as claimed in claim 116 including passing the liquid and gas within a drainage layer along the first side of the fluid treatment layer.
- 123. A method as claimed in claim 122 wherein the drainage layer comprises a mesh layer.
- 124. A method as claimed in claim 116 including maintaining turbulent flow of the liquid and gas on the first side of the fluid treatment layer.
- 125. A fluid treatment method comprising:
passing a fluid through a fluid treatment layer of a fluid treatment element in a first direction; passing a mixture of liquid and gas through the fluid treatment layer in a second direction to dislodge particles from the fluid treatment layer; and discharging the mixture of liquid and gas and the dislodged particles from the fluid treatment element.
- 126. A fluid treatment method comprising:
introducing a process fluid into a hollow center of a pleated fluid treatment element at a first lengthwise end of the fluid treatment element; passing the process fluid outward from the hollow center into a fluid treatment pack surrounding the hollow center; passing the process fluid within the fluid treatment pack in a lengthwise direction of the fluid treatment element along a first surface of a fluid treatment layer of the fluid treatment element; passing a portion of the process fluid through the fluid treatment layer; and discharging process fluid which does not pass through the fluid treatment layer from a second lengthwise end of the fluid treatment element.
- 127. A method as claimed in claim 126 including introducing the process fluid which does not pass through the fluid treatment layer into the hollow center at the second lengthwise end of the fluid treatment element and
discharging the process fluid which does not pass through the fluid treatment layer from the fluid treatment element through the hollow center.
- 128. A fluid treatment method comprising:
introducing a fluid to be treated into a fluid treatment element on a first side of a fluid treatment layer of the fluid treatment element; passing all of the fluid to be treated through the fluid treatment layer; introducing a cleaning fluid into the fluid treatment element on the first side of the fluid treatment layer; and cleaning the fluid treatment layer by passing the cleaning fluid along the first side of the fluid treatment layer to generate a fluid shear force on the first side of the fluid treatment layer.
- 129. A method as claimed in claim 128 wherein the cleaning fluid comprises a gas.
- 130. A method as claimed in claim 129 wherein the cleaning fluid comprises a mixture of liquid and gas.
- 131. A method as claimed in claim 129 including passing the gas through the fluid treatment element at a flow rate of at least about 0.04 scfm per square foot of area of the first side of the fluid treatment layer.
- 132. A fluid treatment method comprising:
introducing a fluid from a first chamber of a housing through a first tube sheet into a first lengthwise end of a pleated fluid treatment element disposed in a second chamber of the housing separated from the first chamber by the first tube sheet; passing the fluid within the fluid treatment element along a radially outer side of a fluid treatment layer of the fluid treatment element in a lengthwise direction of the fluid treatment element to generate a fluid shear force on the radially outer side of the fluid treatment layer while retaining the fluid in the fluid treatment element by a fluid impervious member; and discharging the fluid radially outward from the fluid treatment element into the second chamber in the vicinity of a second lengthwise end of the fluid treatment element.
- 133. A method as claimed in claim 132 wherein the fluid impervious member comprises a tube surrounding the fluid treatment layer, the method including discharging the fluid into the second chamber through at least one opening formed in the tube in the vicinity of the second lengthwise end of the fluid treatment element.
- 134. A method as claimed in claim 132 including passing a portion of the fluid through the fluid treatment layer to a radially inner side of the fluid treatment layer and discharging the portion of the fluid though a second lengthwise end of the fluid treatment element through a second tube sheet into a third chamber of the housing separated from the second chamber by the second tube sheet.
- 135. A fluid treatment method comprising:
introducing a fluid from a first chamber of a housing radially into a fluid treatment element disposed in the first chamber; passing the fluid within the fluid treatment element along a radially outer side of a fluid treatment layer of the fluid treatment element in a lengthwise direction of the fluid treatment element to generate a fluid shear force on the radially outer side of the fluid treatment layer while retaining the fluid in the fluid treatment element by a fluid impervious member; and discharging the fluid from a lengthwise end of the fluid treatment element through a first tube sheet into a second chamber of the housing separated from the first chamber by the first tube sheet.
- 136. A method as claimed in claim 135 wherein the fluid impervious member comprises a tube surrounding the fluid treatment layer, the method including introducing the fluid into the fluid treatment element through at least one opening formed in the tube in a vicinity of a lengthwise end of the fluid treatment element.
- 137. A method as claimed in claim 135 including introducing the fluid into the fluid treatment element in a vicinity of a first lengthwise end of the fluid treatment element and passing the fluid in the lengthwise direction of the fluid treatment element towards a second lengthwise end of the fluid treatment element.
- 138. A method as claimed in claim 137 including discharging the fluid from the first lengthwise end of the fluid treatment element into the second chamber.
- 139. A fluid treatment method comprising:
introducing a fluid to be treated into a pleated fluid treatment element; passing the fluid in a lengthwise direction of the fluid treatment element along a first side of a fluid treatment layer of the fluid treatment element toward a first lengthwise end of the fluid treatment element; passing a portion of the fluid through the fluid treatment layer; discharging the portion of the fluid which passed through the fluid treatment layer from a second lengthwise end of the fluid treatment element; and discharging fluid which did not pass through the fluid treatment layer from the first lengthwise end of the fluid treatment element.
- 140. A method as claimed in claim 139 including introducing the fluid to be treated into the fluid treatment element from a housing chamber in which the fluid treatment element is disposed.
- 141. A method as claimed in claim 140 wherein the fluid treatment element includes a pleated fluid treatment pack containing the fluid treatment layer, including introducing the fluid to be treated through a lengthwise end face of the fluid treatment pack.
- 142. A method as claimed in claim 139 including discharging the fluid which did not pass through the fluid treatment element through a lengthwise end face of the fluid treatment pack.
- 143. A fluid treatment assembly comprising:
a fluid treatment pack; a tube surrounding the fluid treatment pack and having openings at first and second lengthwise ends thereof and a blind region without openings extending between the openings at the first and second ends and extending for at least about 30 percent of the length of the fluid treatment pack; and first and second end caps sealed to the first and second lengthwise ends of the filter pack, respectively.
- 144. An assembly as claimed in claim 143 including a core surrounded by the fluid treatment pack and having openings at first and second lengthwise ends thereof and a blind region extending between the openings over at least about 30 percent of the length of the fluid treatment pack.
- 145. An assembly as claimed in claim 144 wherein each of the end caps has an opening communicating with an interior of the core.
- 146. An assembly as claimed in claim 143 including a housing surrounding the tube and sealed to an exterior of the tube between the openings at opposite lengthwise ends of the tube.
- 147. An assembly as claimed in claim 146 wherein the housing includes a cover disposed at a lengthwise end of the outer wall of the housing and having a first fluid port communicating between an exterior of the housing and an interior of the fluid treatment pack and a second fluid port isolated from the first fluid port and communicating between the exterior of the cover and an interior of the housing between the tube and the outer wall of the housing.
- 148. An assembly as claimed in claim 147 wherein the cover is connected to the outer wall of the housing and the end cap by a melt bond.
- 149. An assembly as claimed in any of claims 143-148 which is constructed of fluoropolymeric components.
- 150. An assembly as claimed in claim 149 wherein said fluoropolymer comprises a homopolymer or copolymer of tetrafluoroethylene (TFE).
- 151. An assembly as claimed in claim 150 wherein said homopolymer is PTFE.
- 152. An assembly as claimed in claim 150 wherein said copolymer comprises TFE and at least one monomer selected from the group consisting of a perfluoroalkylvinylether, perfluoroalkoxydioxole, and perfluoroolefin having 3 or more carbon atoms.
- 153. An assembly as claimed in claim 152 wherein said perfluoroalkylvinylether is perfluoromethylvinylether or perfluoropropylvinylether.
- 154. An assembly as claimed in claim 152 wherein said perfluoroalkoxydioxole is pefluoro-2,2-dimethyl-1,3-dioxole.
- 155. An assembly as claimed in claim 152 wherein said perfluoroolefin is perfluoropropylene.
- 158. An assembly as claimed in any of claims 149-162 wherein said fluid treatment pack comprises a microporous membrane.
- 159. An assembly as claimed in claim 158 wherein said membrane has an average pore rating of from about 0.01 μm to about 10.0 μm.
- 160. An assembly as claimed in claim 159 wherein said membrane has an average pore rating of from about 0.05 μm to about 0.2 μm.
- 161. An assembly as claimed in any of claims 158-160 wherein said membrane comprises a fluoropolymer.
- 167. An assembly as claimed in claim 161 wherein said fluoropolymer is PTFE.
- 168. A method for contacting a gas with a liquid comprising providing an assembly as claimed in any of claims 143-167; passing the gas through one of the first and second ports; and passing the liquid through the other of the first and second ports.
- 169. A method as claimed in claim 168 wherein said gas comprises ozone.
- 170. A method as claimed in claim 168 wherein said gas comprises oxygen.
- 171. A method as claimed in claim 168 wherein said gas comprises HF.
- 172. A method as claimed in claim 168 wherein said gas comprises HCl.
- 173. A method as claimed in claim 168 wherein said gas comprises ClO2.
- 174. A method as claimed in claim 168 wherein said gas comprises ammonia.
- 175. A method as claimed in claim 168 wherein said liquid comprises a corrosive liquid.
- 176. A method as claimed in claim 168 wherein said liquid comprises water.
- 177. A method as claimed in claim 168 wherein said liquid comprises sulfuric acid.
- 178. An arrangement for contacting a liquid with a gas that is soluble in the liquid comprising:
a fluid treatment assembly comprising a housing and a pleated fluid treatment layer having a first and a second side and defining a first flow path and a second flow path along the first and second sides, respectively; a source of said gas connected to the first flow path of the fluid treatment assembly; and a source of said liquid connected to the second flow path of the fluid treatment assembly.
- 179. An arrangement for degassing a liquid containing a dissolved gas comprising:
a fluid treatment assembly comprising a housing and a pleated fluid treatment layer having a first and a second side and defining a first flow path and a second flow path along the first and second sides, respectively; a source of the liquid connected to the first flow path; and a difference in pressure between the first and second flow paths.
- 180. An arrangement as claimed in claim 178 or 179 wherein the first and second flow paths pass in opposite directions.
- 181. An arrangement as claimed in claim 179 wherein the fluid treatment assembly includes a first mesh layer on the first side of the fluid treatment layer and a second mesh layer on the second side of the fluid treatment layer, the first and second flow paths passing within the first and second mesh layers, respectively.
- 182. An arrangement as claimed in claim 181 wherein at least one of the mesh layers comprises a nonwoven mesh.
- 183. An arrangement as claimed in any of claims 178-182 wherein the fluid treatment assembly is cylindrical.
- 184. An arrangement as claimed in claim 183 wherein the fluid treatment layer has axially extending pleats.
- 185. An arrangement as claimed in any of claims 178-184 wherein the fluid treatment assembly is constructed of fluoropolymeric components.
- 186. An arrangement as claimed in claim 185 wherein said fluoropolymer comprises a homopolymer or copolymer of tetrafluoroethylene (TFE).
- 187. An arrangement as claimed in claim 186 wherein said homopolymer is PTFE.
- 188. An arrangement as claimed in claim 186 wherein said copolymer comprises TFE and at least one monomer selected from the group consisting of a perfluoroalkylvinylether, perfluoroalkoxydioxole, and perfluoroolefin having 3 or more carbon atoms.
- 189. An arrangement as claimed in claim 188 wherein said perfluoroalkylvinylether is perfluoromethylvinylether or perfluoropropylvinylether.
- 190. An arrangement as claimed in claim 188 wherein said perfluoroalkoxydioxole is pefluoro-2,2-dimethyl-1,3-dioxole.
- 191. An arrangement as claimed in claim 188 wherein said perfluoroolefin is perfluoropropylene.
- 192. An arrangement as claimed in any of claims 178-191 wherein said fluid treatment layer comprises a microporous membrane.
- 193. An arrangement as claimed in claim 192 wherein said membrane has an average pore rating of from about 0.01 μm to about 10.0 μm.
- 194. An arrangement as claimed in claim 192 wherein said membrane has an average pore rating of from about 0.05 μm to about 0.2 μm.
- 195. An arrangement as claimed in any of claims 192-194 wherein said membrane comprises a fluoropolymer.
- 196. An arrangement as claimed in claim 195 wherein said fluoropolymer is PTFE.
- 197. An arrangement as claimed in any of claims 178-197 wherein said gas comprises ozone.
- 198. An arrangement as claimed in any of claims 178-197 wherein said gas comprises oxygen.
- 199. An arrangement as claimed in any of claims 178-197 wherein said gas comprises HF.
- 200. An arrangement as claimed in any of claims 178-197 wherein said gas comprises HCl.
- 201. An arrangement as claimed in any of claims 178-197 wherein said gas comprises ClO2.
- 202. An arrangement as claimed in any of claims 178-197 wherein said gas comprises ammonia.
- 203. An arrangement as claimed in any of claims 178-197 wherein said liquid comprises a corrosive liquid.
- 204. An arrangement as claimed in any of claims 178-197 wherein said liquid comprises water.
- 205. An arrangement as claimed in any of claims 178-197 wherein said liquid comprises sulfuric acid.
- 206. A method for contacting a liquid with a gas that is soluble in the liquid comprising:
providing a fluid treatment assembly comprising a pleated fluid treatment layer having a first and a second side and defining a first flow path and a second flow path along the first and second sides, respectively; passing the gas along the first flow path; passing the liquid along the second flow path; and passing at least a portion of the gas through the fluid treatment layer to obtain a solution of said gas in the liquid.
- 207. A method for degassing a liquid containing a dissolved gas comprising:
providing a fluid treatment assembly comprising a pleated fluid treatment layer having a first and a second side and defining a first flow path and a second flow path along the first and second sides, respectively; passing the liquid along one of said first side and said second side of the fluid treatment layer; and providing a difference in pressure between the first side and said second side of the fluid treatment layer.
- 208. The method of claim 206 wherein said solution is free or substantially free of bubbles.
- 209. The method of any of claims 207-208 wherein said gas is transferred through the fluid treatment layer diffusively.
- 210. The method of claim 207 wherein said gas and liquid are passed counter-current to each other.
- 211. The method of claim 207 wherein said gas and liquid are passed co-current to each other.
- 212. A fluid treatment method for treating a process fluid containing particles comprising:
providing a pleated fluid treatment element comprising a fluid treatment medium having a first side and a second side; introducing the process fluid into the pleated fluid treatment element; passing at least a portion of the process fluid through a fluid treatment medium of the element from the first side to the second side of the fluid treatment medium; and passing a cleaning gas along the first side of the fluid treatment medium to remove particles from the first side of the fluid treatment medium.
- 213. A method as claimed in claim 212 including introducing the process fluid and the cleaning gas into a drainage layer disposed on the first side of the fluid treatment medium.
- 214. A method as claimed in claim 212 including passing the cleaning gas along the first side of the fluid treatment medium in a lengthwise direction of the fluid treatment element.
- 215. A method as claimed in claim 212 including introducing the process fluid and the cleaning gas into the fluid treatment element at the same lengthwise end of the fluid treatment element.
- 216. A method as claimed in claim 215 including introducing the process fluid and the cleaning gas through an end cap at a lengthwise end of the fluid treatment element.
- 217. A method as claimed in claim 212 including passing a liquid along the first side of the fluid treatment medium together with the cleaning gas.
- 218. A method as claimed in claim 212 including passing a liquid and the cleaning gas sequentially along the first side of the fluid treatment medium.
- 219. A method as claimed in claim 212 wherein the fluid treatment element includes a plurality of pleats each having a radially outer end displaced in a circumferential direction of the fluid treatment element with respect to a radially inner end of the pleat.
- 220. A method as claimed in claim 212 wherein the fluid treatment element has a plurality of pleats each having first and second legs, the first leg being pressed against the second leg of the same pleat and against the second leg of an adjoining pleat over a continuous region extending for a substantial portion of the height of the first leg and over at least fifty percent of an axial length of the fluid treatment element.
- 221. A method as claimed in claim 212 wherein the cleaning gas is passed along the first side of the fluid treatment medium without first passing through the fluid treatment medium.
- 222. A fluid treatment method for treating a process fluid containing particles comprising:
providing a pleated fluid treatment element comprising a fluid treatment medium having a first side and a second side; introducing the process fluid into a drainage layer adjoining the first side of the fluid treatment medium; passing at least a portion of the process fluid through the fluid treatment medium to the second side of the fluid treatment medium; introducing a cleaning gas into the drainage layer and passing the cleaning gas along the first side of the fluid treatment medium to remove particles therefrom; and discharging the particles from the fluid treatment element.
- 223. A method as claimed in claim 222 wherein the fluid treatment element is spirally wound.
- 224. A method as claimed in claim 222 wherein the fluid treatment element has pleats.
- 225. A method as claimed in claim 222 wherein the cleaning gas is passed along the first side of the fluid treatment medium without first passing through the fluid treatment medium.
- 226. A fluid treatment method for treating a process fluid containing particles comprising:
providing an arrangement comprising a plurality of interconnected modules, each module containing a fluid treatment medium having a first side and a second side; introducing the process fluid into the arrangement through a first conduit in each module; passing at least a portion of the process fluid through the fluid treatment medium in each module from the first side to the second side of the fluid treatment medium; introducing a cleaning gas into each module through a second conduit in each module; passing the cleaning gas along the first side of the fluid treatment medium of each fluid treatment element to remove particles from the first side of the fluid treatment medium; and discharging the cleaning gas and the particles from the fluid treatment elements into a third conduit of each module.
- 227. A method as claimed in claim 226 wherein each conduit comprises a bore having two open ends each extending to an exterior surface of one of the modules.
- 228. A fluid treatment arrangement comprising:
a pleated fluid treatment element having first and second lengthwise ends and including a fluid treatment medium; a housing containing the fluid treatment element and having a first fluid port communicating with the first lengthwise end and second and third fluid ports communicating with the second lengthwise end of the fluid treatment element, fluid being able to flow from the first port to the second and third ports through the fluid treatment element without passing through the fluid treatment medium; a source of liquid to be treated connected to one of the first and second fluid ports; and a source of crossflow cleaning gas connected to the third fluid port.
- 229. An arrangement as claimed in claim 228 wherein the housing includes a fourth port communicating with the first lengthwise end of the fluid treatment element and communicating with an opposite side of the fluid treatment medium from the first, second, and third ports.
- 230. An arrangement as claimed in claim 228 wherein the fluid treatment element includes a plurality of pleats each having a radially outer end displaced in a circumferential direction of the fluid treatment element with respect to a radially inner end of the pleat.
- 231. An arrangement as claimed in claim 228 wherein the fluid treatment element has a plurality of pleats each having first and second legs, the first leg being pressed against the second leg of the same pleat and against the second leg of an adjoining pleat over a continuous region extending for a substantial portion of the height of the first leg and over at least fifty percent of an axial length of the fluid treatment element.
- 232. A fluid treatment arrangement comprising:
a fluid treatment element having a fluid treatment medium with first and second sides and a drainage layer on the first side of the fluid treatment medium; a housing containing the fluid treatment element and having a first fluid port communicating with a first lengthwise end and second and third fluid ports communicating with a second lengthwise end of the fluid treatment element, fluid being able to flow from the first port to the second and third ports through the drainage layer without passing through the fluid treatment medium; a source of liquid to be treated connected to one of the first and second fluid ports; and a source of crossflow cleaning gas connected to the third fluid port.
- 233. An arrangement as claimed in claim 232 wherein the fluid treatment element is spirally wound.
- 234. An arrangement as claimed in claim 232 wherein the fluid treatment element has pleats.
- 235. A fluid treatment module comprising:
a first header having a bore for fluid communicating with an exterior surface of the first header and a second header having first and second bores fluidly communicating with an exterior surface of the second header, each of the headers being adapted for fluid connection with a corresponding header of another module such that a plurality of modules can be connected side by side to form an assembly; a casing extending between the first and second headers; and a fluid treatment element disposed in the casing and containing a fluid treatment medium with first and second sides, the bore in the first header communicating with the first side of the fluid treatment medium and the bores in the second header communicating with the second side of the fluid treatment medium.
- 236. A module as claimed in claim 235 wherein each bore has two open ends each communicating with an exterior surface of one of the headers.
- 237. A module as claimed in claim 235 wherein the first bore in the second header is connected to a supply of gas and the second bore in the second header is connected to a supply of a liquid.
- 238. A module as claimed in claim 235 including first and second connecting passages connecting the first and second bores of the second header with the fluid treatment element, the first connecting passage in the second header having a smaller cross section than the second connecting passage in the second header.
- 239. A fluid treatment assembly comprising a plurality of fluid treatment modules each including a first header, a second header, a casing extending between the first and second headers, and a fluid treatment element having a fluid treatment medium disposed in the casing, each of the first headers including a first bore communicating with an exterior surface of the first header, and each of the second headers including first and second bores communicating with an exterior surface of the second header, the modules being connected to one another so that the bores in the first headers are interconnected, so that the first bores in the second headers are interconnected, and so that the second bores in the second headers are interconnected, in each module fluid being able to flow through the fluid treatment element between the bore in the first header and either of the bores in the second header without passing through the fluid treatment medium of the fluid treatment element.
- 240. An assembly as claimed in claim 239 wherein each bore has two open ends each extending to an exterior surface of one of the headers.
- 241. An assembly as claimed in claim 239 wherein each of the first headers includes a second bore communicating with an exterior surface of the first header, the second bore in the first header being on an opposite side of the fluid treatment medium from the other bores in the module.
- 242. An assembly as claimed in claim 239 wherein each fluid treatment element includes a plurality of pleats each having a radially outer end displaced in a circumferential direction of the fluid treatment element with respect to a radially inner end of the pleat.
- 243. An assembly as claimed in claim 239 wherein each fluid treatment element has a plurality of pleats each having first and second legs, the first leg being pressed against the second leg of the same pleat and against the second leg of an adjoining pleat over a continuous region extending for a substantial portion of the height of the first leg and over at least fifty percent of an axial length of the fluid treatment element.
- 244. A method for cleaning a fluid treatment element comprising a fluid treatment layer having a first side and a second side, at least one of said first and second sides having particles deposited thereon, the method comprising passing a cleaning gas along the side of the fluid treatment layer having particles deposited thereon without first passing through the fluid treatment layer.
- 245. A method as claimed in claim 244 wherein said fluid treatment layer is pleated.
- 246. An all fluoropolymer fluid treatment assembly comprising:
a fluid treatment pack; a tube surrounding the fluid treatment pack and having openings at first and second lengthwise ends thereof and a blind region without openings extending between the openings at the first and second ends and extending for at least about 30 percent of the length of the fluid treatment pack; and first and second end caps sealed to the first and second lengthwise ends of the fluid treatment pack, respectively, wherein all components of the fluid treatment assembly are composed of fluoropolymers.
- 247. An assembly as claimed in any of claims 149-162 wherein said fluid treatment pack comprises a nonporous membrane.
- 248. An arrangement as claimed in any of claims 178-191 wherein said fluid treatment layer comprises a nonporous membrane.
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] This application claims priority of U.S. Provisional Application No. 60/099,663, filed Sep. 9, 1998, the disclosure of which is incorporated herein in its entirety by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60099663 |
Sep 1998 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09786724 |
Jul 2001 |
US |
Child |
10702495 |
Nov 2003 |
US |