Apparatus and method for anodizing inner surface of tube

Abstract

Provided is an apparatus for anodizing an internal surface of a tube including an electrolyte container storing an electrolyte solution, a first solution conduit connected with the electrolyte container to receive the electrolyte solution, a first jig configured to fix one end of a targeted tube to a downstream end of the first solution conduit, a second solution conduit in which the other end of the targeted tube is connected to an upstream end to discharge the electrolyte solution flowing into the targeted tube, a second jig configured to fix the other end of the targeted tube to an upstream end of the second solution conduit, and a cathode rod inserted from the second jig and extended to the first jig through the inner portion of the targeted tube, in which, while the electrolyte solution passes through the inner portion of the targeted tube, a cathode is applied to the cathode rod and an anode is applied to the targeted tube to perform an anodizing process.

1 . An apparatus for anodizing an internal surface of a tube, comprising:
 an electrolyte container storing an electrolyte solution;   a first solution conduit connected with the electrolyte container to receive the electrolyte solution;   a first jig configured to fix one end of a targeted tube to a downstream end of the first solution conduit;   a second solution conduit in which the other end of the targeted tube is connected to an upstream end to discharge the electrolyte solution flowing into the targeted tube;   a second jig configured to fix the other end of the targeted tube to an upstream end of the second solution conduit; and   a cathode rod inserted from the second jig and extended to the first jig through the inner portion of the targeted tube,   wherein while the electrolyte solution passes through the inner portion of the targeted tube, a cathode is applied to the cathode rod, and an anode is applied to the targeted tube to perform an anodizing process.   
     
     
         2 . The apparatus of  claim 1 , further comprising a cleaning solution container storing a cleaning solution,
 wherein the cleaning solution container is connected with the electrolyte container and the first solution conduit through a three-way valve.   
     
     
         3 . The apparatus of  claim 2 , further comprising a first constant-temperature water bath receiving a coolant,
 wherein the electrolyte container and the cleaning solution container are installed to be immersed in the coolant of the first constant-temperature water bath.   
     
     
         4 . The apparatus of  claim 2 , wherein a flow meter and a flow control device are installed in the first solution conduit to control a flow of the electrolyte solution or the cleaning solution passing through the first solution conduit. 
     
     
         5 . The apparatus of  claim 1 , further comprising a second constant-temperature water bath receiving a coolant, wherein the targeted tube is installed to be immersed in the coolant of the second constant-temperature water bath. 
     
     
         6 . The apparatus of  claim 1 , wherein in the first jig, a solution conduit connection hole to which the first solution conduit is insert-connected is formed at a first side portion, and a targeted tube connection hole to which one end of the targeted tube is insert-connected is formed at a second side portion. 
     
     
         7 . The apparatus of  claim 6 , wherein the first jig further includes a cathode rod insertion hole to which the cathode rod is inserted, and the targeted tube connection hole and the cathode rod insertion hole of the first jig are formed on a concentric axis. 
     
     
         8 . The apparatus of  claim 1 , wherein in the second jig, a solution conduit connection hole to which the second solution conduit is insert-connected is formed at a first side portion, and a targeted tube connection hole to which the other end of the targeted tube is insert-connected is formed at a second side portion. 
     
     
         9 . The apparatus of  claim 8 , wherein the second jig further includes a cathode rod insertion hole into which the cathode rod is inserted, and the targeted tube connection hole and the cathode rod insertion hole of the second jig are formed on a concentric axis. 
     
     
         10 . The apparatus of  claim 1 , wherein a cooler or a heater is included to control a temperature of the coolant, and a temperature control device that maintains a predetermined temperature during an anodizing reaction by contacting the targeted tube and the coolant is further included. 
     
     
         11 . The apparatus of  claim 1 , wherein the first solution conduit, the targeted tube, and the second solution conduit are connected with each other to form a U-shaped conduit, and the targeted tube is positioned at a downstream branch of the U-shaped conduit. 
     
     
         12 . The apparatus of  claim 1 , wherein the electrolyte solution is a hydrofluoric acid solution. 
     
     
         13 . The apparatus of  claim 1 , wherein the targeted tube is a zirconium tube or a zirconium-alloy tube. 
     
     
         14 . The apparatus of  claim 1 , wherein the cathode rod is a stainless steel rod. 
     
     
         15 . A method for anodizing an internal surface of a tube using an anodizing apparatus including an electrolyte container storing an electrolyte solution, a first solution conduit connected with the electrolyte container to receive the electrolyte solution, a first jig configured to fix one end of a targeted tube to a downstream end of the first solution conduit, a second solution conduit in which the other end of the targeted tube is connected to an upstream end to discharge the electrolyte solution flowing into the targeted tube, and a second jig configured to fix the other end of the targeted tube to an upstream end of the second solution conduit, the method comprising:
 supplying the electrolyte solution to flow through the first solution conduit, the targeted tube, and the second solution conduit;   inserting a cathode rod to be extended to the first jig from the second jig through the inner portion of the targeted tube; and   supplying power by applying a cathode to the cathode rod and applying an anode to the targeted tube,   wherein while the electrolyte solution passes through the inner portion of the targeted tube, an anodizing process is performed.   
     
     
         16 . The method of  claim 15 , further comprising supplying a cleaning solution to flow through the first solution conduit, the targeted tube, and the second solution conduit after power supply stops and the anodizing process ends.