초록 ▼

A filtration medium is disclosed for use in air filters used in heating, ventilating and air conditioning systems. The medium contains at least one nanofiber layer of fibers having diameters less than 1 μm and at least one upstream layer, the medium having sufficient holding capacity for dust partic

A filtration medium is disclosed for use in air filters used in heating, ventilating and air conditioning systems. The medium contains at least one nanofiber layer of fibers having diameters less than 1 μm and at least one upstream layer, the medium having sufficient holding capacity for dust particles that efficiency loss and pressure loss across the medium are minimized during use.

대표청구항 ▼

1. A filter media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is

1. A filter media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 10. 2. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 8. 3. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 6. 4. The media of claim 1 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 5. The media of claim 1 in which the media when loaded with sodium chloride aerosol with a mass mean diameter of 0.26 micron to a final resistance of between 150 and 300 Pa, exhibits a permeability loss of less than about 25% when exposed for 8 hours to air with a relative humidity of 98% at 25° C. 6. The media of claim 1 in which the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 7. The media of claim 1 in which the nanoweb has a basis weight of at least about 2 gsm. 8. The media of claim 7 in which the nanoweb has a basis weight of at least about 3 gsm. 9. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 and about 3 when the media has an efficiency of greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 10. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 2 to about 4 when the media has an efficiency of greater than about 70% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 11. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 4 to about 6 when the media has an efficiency of greater than about 80% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 12. The media of claim 1 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 5 to about 7 when the media has an efficiency of greater than about 90% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 13. The media of claim 1 in which the microfiber web layer has an efficiency less than or equal to 95% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 14. A filter media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the mean flow pore size of the microfiber web layer is between about 13 to about 40 microns. 15. The filter media of claim 14 in which the upstream microfiber web layer has a mean flow pore size of between about 15 to about 25 microns. 16. The filter media of claim 14 in which the upstream microfiber web layer has a mean flow pore size of between about 18 to about 22 microns. 17. The media of claim 14 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 18. The media of claim 14 in which the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 19. The media of claim 14 in which the nanoweb has a basis weight of at least 2 gsm. 20. The media of claim 14 in which the nanoweb has a basis weight of at least 3 gsm. 21. The media of claim 14 in which in which the media has an efficiency between about 50% and 99.97% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 22. A filter media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 50 and about 154 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 23. The media of claim 22 in which the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 57 and about 96 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 24. The media of claim 22 in which the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 69 and about 85 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 25. The media of claim 22 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 26. The media of claim 22 in the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 27. The media of claim 22 in which the nanoweb has a basis weight of at least 2 gsm. 28. The media of claim 22 in which the nanoweb has a basis weight of at least 3 gsm. 29. The media of claim 22 in which in which the media has an efficiency between about 50% and 99.97% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 30. The media of claim 22 in which a scrim is positioned in between the nanofiber web and the upstream nonwoven layer. 31. The media of claim 22 in which the basis weight of the upstream layer is greater than about 10 gsm. 32. The media of claim 22 in which the basis weight of the upstream layer is greater than about 15 gsm. 33. The media of claim 22 in which the basis weight of the upstream layer is greater than about 20 gsm. 34. The media of claim 22 in which the basis weight of the upstream layer is greater than about 30 gsm. 35. The media of claim 22 in which the efficiency of the upstream layer is greater than about 55% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 36. The media of claim 22 in which the efficiency of the upstream layer is greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 37. The media of claim 22 in which the efficiency of the upstream layer is greater than about 65% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 38. The media of claim 1 in which the upstream layer comprises a melt blown polymeric web. 39. The media of claim 1 in which the nanofiber web comprises a nonwoven web made by a process selected from the group consisting of electroblowing, electrospinning, centrifugal spinning and melt blowing. 40. The media of claim 1 which further comprises a scrim support layer in contact with either the nanofiber web or the upstream layer or both. 41. A method of filtering air comprising the step of passing the air through a media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 10. 42. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 8. 43. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 6. 44. The method of claim 41 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 45. The method of claim 41 in which the media when loaded sodium chloride aerosol with a mass mean diameter of 0.26 micron to a final resistance of between 150 and 300 Pa, exhibits a permeability loss of less than about 25% when exposed for 8 hours and air with a relative humidity of 98% at 25° C. 46. The method of claim 41 in which the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 47. The method of claim 41 in which the nanoweb has a basis weight of at least 2 gsm. 48. The method of claim 47 in which the nanoweb has a basis weight of at least 3 gsm. 49. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 1 to about 3 when the media has an efficiency of greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 50. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 2 to about 4 when the media has an efficiency of greater than about 70% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 51. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 4 to about 6 when the media has an efficiency of greater than about 80% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 52. The method of claim 41 in which the ratio of the mean flow pore size of the microfiber web layer to that of the nanofiber web is between about 5 to about 7 when the media has an efficiency of greater than about 90% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 53. The method of claim 41 in which the microfiber web layer has an efficiency less than or equal to 95% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 54. A method of filtering air comprising the step of passing the air through a media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the mean flow pore size of the microfiber web layer is between about 12 to about 40 microns. 55. The method of claim 54 in which the upstream microfiber web layer has a mean flow pore size of between about 15 to about 25 microns. 56. The method of claim 54 in which the upstream microfiber web layer has a mean flow pore size of between about 18 to about 22 microns. 57. The method of claim 54 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 58. The method of claim 54 in which the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 59. The method of claim 54 in which the nanoweb has a basis weight of at least 2 gsm. 60. The method of claim 54 in which the nanoweb has a basis weight of at least 3 gsm. 61. The method of claim 54 in which in which the media has an efficiency between about 50% and 99.97% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 62. A method of filtering air comprising the step of passing the air through a media comprising a nanofiber web with a number average fiber diameter of less than one micron and an upstream microfiber web layer in a face to face relationship with the nanofiber web where the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 50 and about 154 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 63. The method of claim 62 in which the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 50 and about 154 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 64. The method of claim 62 in which the ratio of the mean flow pore size of the microfiber web layer to a particle size is between about 50 and about 154 when the media has an efficiency of between 50% and 99.97% when impinged upon by particles of the particle size. 65. The method of claim 62 in which the filter media exhibits an efficiency drop when filtering particles of size 0.26 microns of less than 5% over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 66. The method of claim 62 in the filter media exhibits a pressure drop increase of less than 200 Pa when filtering particles of size 0.26 microns over 0.5 hours in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 67. The method of claim 62 in which the nanoweb has a basis weight of at least 2 gsm. 68. The method of claim 62 in which the nanoweb has a basis weight of at least 3 gsm. 69. The method of claim 62 in which in which the media has an efficiency between about 50% and 99.97% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 70. The method of claim 41 in which a scrim is positioned in between the nanofiber web and the upstream nonwoven layer. 71. The method of claim 41 in which the basis weight of the upstream layer is greater than about 10 gsm. 72. The method of claim 41 in which the basis weight of the upstream layer is greater than about 15 gsm. 73. The method of claim 41 in which the basis weight of the upstream layer is greater than about 20 gsm. 74. The method of claim 41 in which the basis weight of the upstream layer is greater than about 30 gsm. 75. The method of claim 41 in which the efficiency of the upstream layer is greater than about 55% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 76. The method of claim 41 in which the efficiency of the upstream layer is greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 77. The method of claim 41 in which the efficiency of the upstream layer is greater than about 65% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 78. The method of claim 41 in which the upstream layer comprises a melt blown polymeric web. 79. The method of claim 41 in which the nanofiber web comprises a nonwoven web made by a process selected from the group consisting of electroblowing, electrospinning, centrifugal spinning and melt blowing. 80. The method of claim 41 which further comprises a scrim support layer in contact with either the nanofiber web or the upstream layer or both. 81. The media of claim 1 in which a scrim is positioned in between the nanofiber web and the upstream nonwoven layer. 82. The media of claim 1 in which the basis weight of the upstream layer is greater than about 10 gsm. 83. The media of claim 1 in which the basis weight of the upstream layer is greater than about 15 gsm. 84. The media of claim 1 in which the basis weight of the upstream layer is greater than about 20 gsm. 85. The media of claim 1 in which the basis weight of the upstream layer is greater than about 30 gsm. 86. The media of claim 1 in which the efficiency of the upstream layer is greater than about 55% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 87. The media of claim 1 in which the efficiency of the upstream layer is greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 88. The media of claim 1 in which the efficiency of the upstream layer is greater than about 65% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 89. The media of claim 14 in which a scrim is positioned in between the nanofiber web and the upstream nonwoven layer. 90. The media of claim 14 in which the basis weight of the upstream layer is greater than about 10 gsm. 91. The media of claim 14 in which the basis weight of the upstream layer is greater than about 15 gsm. 92. The media of claim 14 in which the basis weight of the upstream layer is greater than about 20 gsm. 93. The media of claim 14 in which the basis weight of the upstream layer is greater than about 30 gsm. 94. The media of claim 14 in which the efficiency of the upstream layer is greater than about 55% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 95. The media of claim 14 in which the efficiency of the upstream layer is greater than about 60% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3. 96. The media of claim 14 in which the efficiency of the upstream layer is greater than about 65% when filtering particles of size 0.26 microns in a test in which a flat-sheet media with a circular opening of 11.3 cm diameter is subjected to a sodium chloride aerosol with a mass mean diameter of 0.26 micron, an air flow rate of 40 liter/min corresponding to a face velocity of 6.67 cm/s, and an aerosol concentration of 16 mg/m3.