| 摘要 |
<p>PURPOSE:To prevent the inflow of treated gas into a support insulator, by providing a heater in a support insulator protecting cylinder, and circulating air heated by said heater in the support insulator by convection on the basis of the difference of specific gravity due to the temp. difference with treated gas. CONSTITUTION:Prior to starting the operation of EP, air in a support insulator 104 is heated by an electric heater 111 and heated air moves to the upper part of a support insulator 104. When the operation of EP is started in this state, treated gas 114 is flowed into EP. In this case, the temp. of the treated gas 114 is detected by a temp. detector 15 while the temp. of heated air 116 is detected by a temp. detector 117 and the electric heater 111 is controlled by a controller so as to make the temp. of the heated air 116 slightly higher than that of the treated gas 114. Therefore, the treated gas 114 is prevented from flowing into the support insulator 104 by the difference of specific gravity and the adhesion of dust to the inner surface of the support insulator 104 is prevented.</p> |
