Evaporative fuel treating device and method

摘要

A canister adsorbs evaporative fuel generated in a fuel tank. A purge gas circulation pump causes canister outlet gas to flow out from the canister. A high-concentration separation unit separates canister outlet gas into high-concentration treating gas and medium-concentration gas. A medium-concentration separation unit separates medium-concentration gas flowing out from the high-concentration unit into medium-concentration circulating gas and low-concentration canister inlet gas. Treating gas is introduced into the fuel tank. Circulating gas is caused to circulate upstream of the purge gas circulation pump. Canister inlet gas is caused to circulate upstream of the canister.