Method of cleaning passageways using a mixed phase flow of a gas and a liquid

Abstract

A method of cleaning surfaces using a mixed phase cleaning mixture of an aqueous solution and a flow of gas sufficient to produce droplets of the liquid which are entrained by the gas for a time sufficient to clean tubing of various lengths and geometries and porous membranes to remove biofilm, debris and contaminants.

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 - 7 . (canceled)  
     
     
         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 - 22 . (canceled)  
     
     
         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 or surfactants, alcohols, a pH modifier, a chelating agent, a humectant, a viscosity modifier and an anti-foaming agent.  
     
     
         26 . (canceled)  
     
     
         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 contains 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 - 43 . (canceled)