Vapor treatment system for volatile liquid

Abstract

A vapor treatment system incorporated with an automotive fuel storage tank for a gasoline. The vapor treatment system comprises a vapor adsorbent canister containing therein vapor adsorbent. A first ventilation line is provided to have a first end section connected to an upper space inside the storage tank, and a second end section connected to the vapor adsorbent canister. A vapor control valve is disposed in the first ventilation line to control flow of vapor of the gasoline passing through the first ventilation line. A second ventilation line is provided to have a first end section connected to a liquid supply pipe through which the gasoline is supplied into the storage tank, and a second end section connected to the vapor adsorbent canister. A vapor-liquid contacting device is provided to include a container disposed inside the storage tank. A return line is provided such that the gasoline is returned from an engine through it into the storage tank. The return line has an end section located in the container of the vapor-liquid contacting device so as to fill the container with the returned gasoline. A purge line is provided to have a first end section located in the container and close to a bottom of the container of the vapor-liquid contacting device, and a second end section connected to the vapor adsorbent canister. Additionally, a vacuum pump is disposed in the purge line and operated to purge the vapor from the vapor adsorbent and feed the purged vapor into the container of the vapor-liquid contacting device so that the vapor is absorbed in the gasoline in the container of the vapor-liquid contacting device.