Claims
- 1. A method of removing biofilm, debris and contaminants from surfaces of a passageway comprising forming a mixed-phase flow along a surface of the passageway from a mixture of gas and a liquid that creates shear or impact stresses for a time sufficient to remove biofilm, debris and contaminants from the surfaces.
- 2. A method according to claim 1 wherein the liquid has a surface tension of at least 18 dynes/cm up to about 72 dynes/cm.
- 3. A method according to claim 1 wherein the velocity of the gas is greater than 1 meter/second.
- 4. A method according to claim 1 wherein the velocity of the gas is from about 10 meters to 100 meters/second.
- 5. A method according to claim 1 wherein the passageway includes one or more changes of direction.
- 6. A method according to claim 1 wherein the passageway divides into multiple passageways.
- 7. A method according to claim 1 wherein the passageway is either the shell side or tube side of a shell and tube geometry.
- 8. A method according to claim 1 wherein the passageway is a biopsy device.
- 9. A method according to claim 1 wherein at least a portion of the surface of the passageway is a permeable membrane.
- 10. A method according to claim 1 wherein the passageway comprises a hemodialyzer.
- 11. A method according to claim 1 wherein the direction of flow of the mixed-phase flow is reversed one or more times.
- 12. A method according to claim 1 wherein the mixed phase flow is pulsed.
- 13. A method according to claim 1 wherein the ratio of the volumetric flow rate of the gas at standard conditions to the volumetric flow rate of the liquid is between about 50:1 to about 6000:1.
- 14. A method according to claim 1 wherein after removal of the biofilm, debris and contaminants, the passageway is rinsed.
- 15. A method according to claim 1 wherein the mixed-phase flow comprises liquid droplets dispersed in the gas.
- 16. A method according to claim 15 wherein the droplets are pulled from the surface of the liquid by hydrodynamic instability.
- 17. A method according to claim 1 wherein the mixed-phase flow comprises a plurality of interconnected liquid films or light foam.
- 18. A method according to claim 1 wherein the portion of liquid introduced into the passageway through a permeable membrane reacts with the flow flowing within the passageway to form bubbles.
- 19. A method according to claim 1 wherein two different liquids are alternately introduced into a passageway to form bubbles by chemical reaction.
- 20. A method according to claim 1 wherein the mixed phase flow is formed by the release of a gas dissolved in the liquid.
- 21. A method according to claim 1 wherein the liquid includes solid particles.
- 22. A method according to claim 1 wherein the liquid includes one or more biocides.
- 23. A method according to claim 1 wherein the liquid includes one or more surfactants.
- 24. A method according to claim 1 wherein the liquid includes one or more oxidizing agents.
- 25. A method according to claim 1 wherein the liquid is selected from one or more members of the group consisting of surfactants, alcohols, a pH modifier, a chelating agent, a humectant, a viscosity modifier and an anti-foaming agent.
- 26. A method of claim 10 wherein the mixed-phase flow is formed by adding the liquid into the permeable surface of the passageway wherein the gas is flowing.
- 27. A method of removing biofilm, debris and contaminants from the exposed surfaces of a passageway having a portion of the surfaces comprised of a permeable membrane comprising
forming a mixed phase mixture of a liquid and a gas having a volumetric ratio of gas to liquid greater than 50:1 by introducing at least a portion of the liquid into the passageway through the permeable membrane and mixing the liquid with the gas flowing within the passageway at a sufficient velocity for a sufficient time to remove the biofilm, debris and contaminants.
- 28. A method according to claim 27 wherein the portion of liquid introduced into the passageway through the permeable membrane reacts with the fluid flowing within the passageway to form bubbles.
- 29. A method according to claim 27 wherein the liquid is exposed to a pressure drop sufficient to initiate boiling.
- 30. A method according to claim 27 wherein the liquid containws a dissolved gas which forms bubbles due to the pressure drop through the membrane.
- 31. A method according to claim 27 wherein the passageways comprise a hemodialyzer.
- 32. A method according to claim 27 wherein the passageways comprise a hollow fiber membrane filter.
- 33. A method according to claim 27 wherein the passageways comprise a tubular membrane filter.
- 34. A method according to claim 1 wherein the passageway divides into a plurality of conduits, each conduit having surfaces, wherein the opposite side of each of said surfaces defines part of the boundary of another conduit.
- 35. A method according to claim 1 wherein the passageway comprises an input header, a plurality of conduits, and wherein the mixed-phase flow contacts the inside of the conduits and the inside of the input header and the output header.
- 36. A method according to claim 1 wherein a plurality of liquids successively removes different types of biofilm, debris and contaminants.
- 37. A method according to claim 1 wherein prior to forming the mixed-phase flow, the passageway is soaked in the liquid to soften the biofilm, debris and contaminants.
- 38. A method according to claim 1 wherein the mixed-phase flow is heated above ambient temperature.
- 39. A method according to claim 1 wherein the inlet pressure of the gas is at least 15 psig.
- 40. A method according to claim 1 wherein the passageway is exposed to ultrasonic vibrations during the removal period.
- 41. A method according to claim 9 wherein the exterior of the passageway is subjected to a pressurized gas.
- 42. A method according to claim 9 wherein the exterior of the passageway is subject to a pressurized liquid.
- 43. A method according to claim 41 wherein the liquid includes a dissolved gas.
Parent Case Info
[0001] This application is a continuation-in-part of copending application Ser. No. 08/880,662.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09466714 |
Dec 1999 |
US |
Child |
10197287 |
Jul 2002 |
US |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
08880662 |
Jun 1997 |
US |
Child |
10197287 |
Jul 2002 |
US |