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US 8,281,570 B2Granted
Reducing agent injector having purge heater
AssigneeCaterpillar Inc.
InventorsJohn D. Gierszewski, Glenn B. Cox
Life of this patent
Estimating the term…
Abstract
A method of introducing a reducing agent into an exhaust stream may include injecting the reducing agent into the exhaust gas stream using a reducing agent injector. The method may further include selectively heating a nozzle of the reducing agent injector to reduce residue on the nozzle.
Claims15
A method of introducing a reducing agent into an exhaust stream, the method comprising:
- injecting the reducing agent into the exhaust gas stream using a reducing agent injector having a nozzle;
- and
- sensing residue on the nozzle based on a pressure level of the reducing agent upstream of the nozzle and within the reducing agent injector and exceeding a threshold pressure level;
- generating a triggering condition when the pressure level of the reducing agent exceeds the threshold pressure level;
- and
- selectively heating the nozzle of the reducing agent injector in response to the triggering condition to reduce the residue on the nozzle.
3 more elements
A method for cleaning residue from a reducing agent injector of an aftertreatment system, the method comprising:
- sensing residue on a nozzle of the reducing agent injector based on a pressure level of a reducing agent upstream of the nozzle and within the reducing agent injector and being outside of a predetermined range;
- generating a triggering condition when the pressure level of the reducing agent falls outside of the predetermined range, the triggering condition being indicative of the presence of residue interfering with the injection of the reducing agent by the reducing agent injector;
- activating a heater in response to the triggering condition;
- and
- heating the nozzle of the reducing agent injector with the heater to remove the residue from the nozzle.
2 more elements
A system for performing selective catalytic reduction, the system comprising:
- a reducing agent injector including a nozzle and configured to inject a reducing agent into exhaust in an exhaust passage through the nozzle;
- a pressure sensor configured to sense a pressure level of the reducing agent upstream of the nozzle and within the reducing agent injector;
- a heater coupled to a nozzle of the reducing agent injector;
- a catalyst configured to receive a mixture of reducing agent and exhaust from the exhaust passage;
- and
- a controller coupled to the heater and the pressure sensor, the controller configured to activate the heater to remove residue from the nozzle based on an indication that residue has accumulated in the nozzle, wherein the indication is the sensed pressure level falling outside of a predetermined range.
3 more elements
Dependencies are inferred from the claim text.