| 摘要 |
<p>PURPOSE:To spray washing liquid with a necessary minimum frequency in order to remove scale, etc., stuck to the dust collecting electrode and the discharging electrode, to restrain the surface of the dust collecting electrode and the discharging electrode from being oxidized and simultaneously to restrict the amount used of an alkali agent to a necessary minimum. CONSTITUTION:A washing liquid spraying means, an alkali liquid spraying means, a pH detector 42, and a control means 43 are provided. The washing liquid is intermittently sprayed on the dust collecting electrode and the discharging electrode by the washing liquid spraying means, and the alkali liquid is sprayed on the dust collecting means and the discharging means and simultaneously the pH value of the liquid falling from the lower end of at least one of the dust collecting and discharging electrodes is detected by the pH detector. Based on the detected value, the amount sprayed of the alkali liquid is controlled by the control means so that the pH value of the alkali liquid may be >=4.</p> |
