SCR exhaust gas aftertreatment device
AssigneeCummins Inc.
InventorsAlexandre Branco, Heico Stegmann, Friedrich Zapf
Life of this patent
Estimating the term…
Abstract
The invention relates to an SCR exhaust gas aftertreatment device, particularly for diesel motor internal combustion engines having a very large exhaust gas volume and/or divided exhaust gas trains. In order to be able to manufacture this SCR exhaust gas aftertreatment device in a cost-efficient manner, also for a high mixing degree of exhaust gas and AUS, it is proposed that a plurality of metering units (D1, D2, Dn) is provided, each of which has an atomizing nozzle, which nozzle-injects the aqueous urea solution into the exhaust gas train. In this case, the pressure existing in a common line for all metering units (D1, D2, Dn) can be determined by means of a pressure sensor.
Claims23
An SCR exhaust gas aftertreatment device comprising:
- a pump (2) configured to pressurize an aqueous urea solution in a line (50) connected to each inlet connection (157a, 157b) of each metering unit of a plurality of metering units (D1, D2, Dn), each metering unit of the plurality of metering units (D1, D2, Dn) having a metering valve (34) connected to the each inlet connection (157a, 157b) and the line (50) and an atomizing nozzle (101) to nozzle-inject the aqueous urea solution into an exhaust gas train (177), each metering unit of the plurality of metering units (D1, D2, Dn) having an outflow connection (156a, 156b), separate from the line (50), leading via a proportional valve (223) to a tank (200), and a pressure sensor (221) configured to determine a pressure existing in the line (50), each metering unit of the plurality of metering units (D1, D2, Dn) configured to nozzle-inject a portion of the aqueous urea solution into the exhaust gas train (177) while the pump (2) simultaneously circulates another portion of the aqueous urea solution via the proportional valve (223) to the tank (200).
An SCR exhaust gas aftertreatment device comprising:
- a pump (2) configured to pressurize an aqueous urea solution in a line (50) connected to each inlet connection (157a, 157b) of each metering unit of a plurality of metering units (D1, D2, Dn), each metering unit of the plurality of metering units (D1, D2, Dn) having a metering valve (34) connected to the each inlet connection (157a, 157b) and the line (50), an atomizing nozzle (101) to nozzle-inject the aqueous urea solution into an exhaust gas train (177), an outflow connection (156a, 156b), separate from the line (50), leading via a proportional valve (223) to a tank (200), and a pressure sensor (221) configured to determine a pressure existing in the line (50), wherein a predominant theoretical value for regulating the pump (2) is formed from a mean value of output signals of the pressure sensors (221).
An SCR exhaust gas aftertreatment device comprising:
- a pump (2) configured to pressurize an aqueous urea solution in a line (50) connected to each inlet connection (157a, 157b) of each metering unit of a plurality of metering units (D1, D2, Dn), each metering unit of the plurality of metering units (D1, D2, Dn) having a metering valve (34) connected to the each inlet connection (157a, 157b) and the line (50), an atomizing nozzle (101) to nozzle-inject the aqueous urea solution into an exhaust gas train (177), an outflow connection (156a, 156b), separate from the line (50), leading via a proportional valve (223) to a tank (200), and a pressure sensor (221) configured to determine a pressure existing in the line (50), wherein a predominant theoretical value for regulating the pump (2) is formed from a mean value of output signals of the pressure sensors (221), and the proportional valve (223) is completely closed when a quantity of aqueous urea solution to be injected is at a maximum.
Dependencies are inferred from the claim text.