| 摘要 |
PURPOSE:To prevent the deterioration of a main adsorption agent by providing an auxiliary adsorption agent for adsorbing high boiling point HC in the upstream of the main adsorption agent for removing low boiling point HC. CONSTITUTION:An exhaust passage 7 is provided with an auxiliary adsorption agent 11 for adsorbing high boiling point HC, and a bypass passage 9 branched at the downstream thereof is provided with a main adsorption agent 13 for adsorbing low boiling point HC. Furthermore, an opening and closing control valve 15 is provided at the inlet 25 of the bypass passage 9. And depending upon the temperature of exhaust gases from a temperature detector 3, a control device 13 opens and closes the control valve 15. Namely, when the temperature of exhaust gases has risen and exceeded a level wherein an odor composition begins to come off the adsorption agent 11, the control valve 15 closes and a main exhaust passage is opened, thereby shutting off the bypass passage 9. According to the aforesaid constitution, the deterioration of the main adsorption agent 13 can be prevented.
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