US Patent Application No. 13/602,195, Reductant Dosing Device with Purging Means
This technology is about a dosing apparatus with purging means for delivering reductant into an exhaust gas treatment system of an internal combustion engine. The apparatus includes a first Venturi T connector with two high pressure ports and a low pressure port, and a purge control valve for switching from normal dosing to purging by controlling flow through the two high pressure ports. The apparatus may also include a second Venturi T connector and a reductant supply chamber for purging reductant residue in its pump and reductant passage lines. The apparatus may further include a purging controller that triggers a purging event according to engine oil or coolant temperature and controls the purging process after a dosing process completes.
Uniqueness and benefits of this technology:
1. Purging residue in a reductant dosing system with a Venturi device and no reverting valve is required;
2. Reductant fluid only flows in one direction, therefore hot air won’t enter pump during purging when the dosing system is used for delivering reductant in exhaust air;
3. A purging controller uses coolant or oil temperature to avoid frequently purging in stop and go applications.