Ozone generation apparatus

Abstract

An ozone generation apparatus includes a cylindrical shaped first electrode, a cylindrical shaped second electrode disposed coaxially with the first electrode and disposed in the first electrode, a dielectric disposed between the first electrode and the second electrode. Dry air is supplied between the first electrode and the second electrode as raw material gas. A discharge gap length d formed by the first electrode, the second electrode, and the dielectric is set to be in a range of 0.3 to 0.5 mm. A pd product, which is a product of the discharge gap length d and a gas pressure p of the raw material gas, is in a range of 6 to 16 kPa·cm. And the discharge gap length d and the gas pressure p of the raw material gas are set to satisfy following expression.

1 . An ozone generation apparatus comprising:
 a cylindrical shaped first electrode;   a cylindrical shaped second electrode disposed coaxially with the first electrode and disposed in the first electrode;   a dielectric disposed between the first electrode and the second electrode; and   a power supply for applying a voltage between the first electrode and the second electrode,   wherein   dry air is supplied between the first electrode and the second electrode as raw material gas, a voltage is supplied between the first electrode and the second electrode from the power supply to generate discharge, and ozone is generated by the discharge,   a discharge gap length d formed by the first electrode, the second electrode, and the dielectric is set to be in a range of 0.3 to 0.5 mm,   a pd product, which is a product of the discharge gap length d and a gas pressure p of the raw material gas, is in a range of 6 to 16 kPa·m, and   the discharge gap length p and the gas pressure p of the raw material gas are set to satisfy expression
   ( pd− 250 d− 3.16) 2 +150 d≦ 12.5 
   
     
     
         2 . The ozone generation apparatus according to  claim 1 , wherein the dielectric is cylindrical shaped. 
     
     
         3 . The ozone generation apparatus according to  claim 2 , wherein
 the second electrode is provided on an inner circumference face of the dielectric, and   further comprising a plurality of projections provided on an inner circumference face of the first electrode to come in contact with an outer circumference face of the dielectric and maintain the discharge gap length d between the first electrode and the dielectric, and formed of same material as that of the first electrode to have a height equivalent to the discharge gap length d.   
     
     
         4 . The ozone generation apparatus according to  claim 2 , wherein
 the second electrode is provided on an inner circumference face of the dielectric, and   further comprising a plurality of projections provided on an outer circumference face of the dielectric to come in contact with an inner circumference face of the first electrode and maintain the discharge gap length d between the dielectric and the first electrode, and formed of same material as that of the dielectric to have a height equivalent to the discharge gap length d.   
     
     
         5 . The ozone generation apparatus according to  claim 2 , wherein the second electrode is a conductor formed on an inner circumference face of the dielectric by means of a sputtering method using a conductor as a target. 
     
     
         6 . The ozone generation apparatus according to  claim 5 , wherein the conductor is stainless steel. 
     
     
         7 . The ozone generation apparatus according to  claim 2 , wherein the second electrode is a conductor formed on an inner circumference face of the dielectric by plating. 
     
     
         8 . The ozone generation apparatus according to  claim 7 , wherein the conductor is nickel. 
     
     
         9 . The ozone generation apparatus according to  claim 1 , wherein the gas pressure p of the raw material gas is set to be smaller than 0.3 MPa. 
     
     
         10 . The ozone generation apparatus according to  claim 1 , wherein a frequency of the power supply is in a range of 1 to 3.5 kHz.