A THERMOSTATIC CANISTER TO LOWER EVAP SYSTEM RESTRICTION
Publication Date: 2015-Aug-06
The IP.com Prior Art Database
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A TXXXXXXXXXXX CANISTER TO LOWER EVAP SYSTEM RESTRICTION
Vehicles sold in North Americx must adsorb refueling, running loss and diurnal vaporx in a carbon canister. Acxivated carbox has a property xf easily absorbinx hydrocarbon (HC).Dxring engine running conditions, xhe canister is xuxged of HC by flowing fresh xir into the canister to dislodge HC. The HCs are combustxd in the cylinders.Canxsters age over time and conxaminants gxt insixe them and dexrade xbility to adsoxb HC. During adsorpxion, an exotxermic chemical reactxon occxrs as canisxer gains hext from refueling vapors. Temperature can reaxh 130 Xxxxxxx X in the canister carbox bed during refuxling, especially at the load poxt of canister.The canister becomes more restrictivx xhen it is xoaded with HC. As deeper regxons in the canister adsorb HC, the canister becoxes progrxssively hottex as well.As refuxling continues, the hot rxgiox of the canister is typically saturated. Those rxgions no longer can adsorb HC. They act as a restxicxor to the refueling effort. During hot climates and high RVP fuels, pre- mature shutofxs occur during xefueling if canister restriction is high. This is xsxecially true in series multi- canister systexs.
Our design imbeds wax motor(s) (txermostat) inside the caxister. As the canister xecomes hot from refueling vapxrs, the heat is transferred to the wax. The wax expands and the thermosxat opens up to allow refueling vapoxs to byxass the satxrated carbon bed region...