Apparatus for Chlorine Dioxide Generation

Abstract

Apparatus for producing chlorine dioxide comprises an electrolysis cell having an anode and a cathode which receives sodium chlorite solution as an anolyte flow and water as a catholyte flow, a chlorine dioxide gas separator which releases chlorine dioxide gas from the anolyte flow which leaves the cell and a separator which releases hydrogen gas from the catholyte flow which leaves the cell. The anolyte and catholyte flows are recirculated from the separators to the cell.

1 . Apparatus for producing chlorine dioxide comprising an electrolysis cell having an anode and a cathode which receives sodium chlorite solution as an anolyte flow and water as a catholyte flow, a separator which releases chlorine dioxide gas from the anolyte flow which leaves the cell and a separator which releases hydrogen gas from the catholyte flow which leaves the cell. 
     
     
         2 . The apparatus of  claim 1  in which the anode is formed from coated titanium mesh with an electrocatalytic coating and the cathode is formed from plain titanium mesh. 
     
     
         3 . The apparatus of  claim 1  in which the anode and cathode chambers are separated by an ion exchange membrane. 
     
     
         4 . The apparatus of  claim 1  in which the gap between the anode and cathode is between 0 and 5 mm. 
     
     
         5 . The apparatus of  claim 1  in which the shadow area current of the anode is between 1000 and 3500 amps/m2. 
     
     
         6 . The apparatus of  claim 1  in which the flow velocity of the anolyte solution over the anode is between 5 and 100 m/min. 
     
     
         7 . The apparatus of  claim 1  in which the cell is provided with channels carrying coolant to cool the anolyte and catholyte flows. 
     
     
         8 . The apparatus of  claim 1  which the cell is encased within metallic plates. 
     
     
         9 . The apparatus of  claim 1  in which the chlorine dioxide gas separator is a tube which receives the anolyte flow tangentially facilitating the release of chlorine dioxide gas through the top of the separator and allowing residual chlorine dioxide and sodium chlorite solution to fall to a reservoir in the bottom of the separator to be recirculated in the anolyte flow. 
     
     
         10 . The apparatus of  claim 9  in which air is introduced at the top of the separator to assist the release of chlorine dioxide gas. 
     
     
         11 . The apparatus of  claim 9  in which the tube has a conical. 
     
     
         12 . The apparatus of  claim 1  in which the hydrogen separator is an open pipe which receives the catholyte flow and allows the hydrogen gas to escape out of the top of the pipe and the residual catholyte to fall to the bottom of the separator whence it is recycled to the cell.