Membrane cleaning apparatus

Abstract

A membrane cleaning apparatus for removing particles from a membrane, the apparatus including a membrane support and an electric field generating mechanism. The membrane support is for supporting the membrane. The electric field generating mechanism is for generating an electric field in the vicinity of the membrane when supported by the membrane support. The electric field generating mechanism may include: one or more collector electrodes; and a mechanism for applying a voltage across a membrane supported by the membrane support and the or each of the one or more collector electrodes.

1 .- 28 . (canceled) 
     
     
         29 . A method for removing particles from a membrane, the method comprising:
 inducing mechanical oscillations in the membrane; and   generating an electric field in the vicinity of the membrane using a collector electrode so as to exert an electrostatic force between the particles on the membrane and the collector electrode.   
     
     
         30 . The method of  claim 29 , wherein the inducing mechanical oscillations in the membrane comprises applying a time-varying voltage across the membrane and the excitation electrode. 
     
     
         31 . The method of  claim 30 , wherein the time-varying voltage has a duty cycle of less than 10%. 
     
     
         32 . The method of  claim 29 , wherein the inducing mechanical oscillations in the membrane comprises applying a time-varying voltage across two electrodes positioned proximate to the membrane. 
     
     
         33 . The method of  claim 29 , wherein the inducing mechanical oscillations in the membrane comprises irradiating at least a portion of the membrane with a pulsed radiation beam. 
     
     
         34 . The method of  claim 29 , wherein the mechanical oscillations induced comprise oscillations at a range of frequencies. 
     
     
         35 . The method of  claim 29 , wherein the mechanical oscillations induced comprise oscillations between 30 kHz and 30 MHz. 
     
     
         36 . The method of  claim 29 , wherein the mechanical oscillations induced are suitable for removing particles with a dimension between 0.5 and 5 μm from the membrane. 
     
     
         37 . The method of  claim 29 , further comprising controlling a temperature of at least a portion of the membrane. 
     
     
         38 . The method of  claim 37 , further comprising varying a temperature of at least a portion of the membrane over time. 
     
     
         39 . The method of  claim 37 , wherein the controlling the temperature of the at least a portion of the membrane is achieved by irradiating the at least a portion using radiation. 
     
     
         40 . A method for removing particles from a membrane, the method comprising:
 generating an electric field in the vicinity of two opposed surfaces of the membrane, the electric field in the vicinity of the two opposed surfaces of the membrane being in opposite directions.   
     
     
         41 . The method of  claim 40 , wherein generating the electric field comprises applying a time-varying voltage across two electrodes positioned proximate to the membrane. 
     
     
         42 . The method of  claim 40 , wherein the electric field is generated by a first electrode at a first surface of the two opposed surfaces of the membrane and a second electrode at a second surface of the two opposed surface of the membrane and wherein a position of the first electrode, in a plane parallel to the plane of the membrane, does not align with a position of the second electrode. 
     
     
         43 . The method of  claim 40 , wherein the magnitude of the electric field is substantially equal on both sides of the membrane. 
     
     
         44 . A method for removing particles from a membrane, the method comprising:
 providing a plasma adjacent to at least one surface of the membrane so as to charge the particles; and   generating an electric field across the membrane so as to force these charged particles away from the membrane.   
     
     
         45 . The method of  claim 44 , wherein the electric field is generated using one or more electrodes and applying a biasing voltage to the one or more electrodes. 
     
     
         46 . The method of  claim 45 , wherein the biasing voltage is a pulsed biasing voltage. 
     
     
         47 . The method of  claim 46 , wherein each pulse of the pulsed voltage comprises a first portion having a first polarity and a second portion having a second, opposite polarity. 
     
     
         48 . The method of  claim 46 , wherein providing the plasma adjacent to the at least one surface of the membrane is such that the plasma is switched on between subsequent pulses of the pulsed voltage and is switched off during pulses of the pulsed voltage.