Reductant dosing system
AssigneeCaterpillar Inc.
InventorsYongxiang Li, Jinhui Sun
Life of this patent
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Abstract
A reductant dosing system for an engine is disclosed. The reductant dosing system may have a supply of reductant, a reservoir configured to hold pressurized reductant, and a pump configured to draw reductant from the supply and discharge reductant at an elevated pressure into the reservoir. The reductant dosing system may also have a plurality of injectors fluidly connected to the reservoir, and a drain valve fluidly connected between the reservoir and the supply.
Claims15
A reductant dosing system for an engine, comprising:
- a supply of reductant;
- a reservoir configured to hold pressurized reductant, the reservoir being an enclosed chamber;
- a pump configured to draw reductant from the supply and discharge reductant at an elevated pressure into the reservoir, the reservoir being mounted to the pump and the pump being mounted to the supply;
- two injectors fluidly connected to the reservoir and configured to independently inject pressurized reductant into exhaust from the engine upstream of an aftertreatment component;
- an annular mounting member configured to hold the injectors at equally spaced intervals around an exhaust duct;
- and
- a coolant jacket that surrounds and supplies engine coolant to the annular mounting member and the injectors;
- and
- a controller in communication with the injectors and being configured to activate the injectors to inject pressurized reductant when a pressure of reductant within the reservoir is a desired pressure,
- wherein the reservoir has an expandable volume.
A reductant dosing system for an engine, comprising:
- a supply of reductant;
- a reservoir configured to hold pressurized reductant;
- a pump configured to draw reductant from the supply and discharge reductant at an elevated pressure into the reservoir;
- two injectors fluidly connected to the reservoir and configured to independently inject pressurized reductant into exhaust from the engine upstream of an aftertreatment component;
- an annular mounting member configured to hold the injectors at equally spaced intervals around an exhaust duct;
- and
- a coolant jacket that surrounds and supplies engine coolant to the annular mounting member and the injectors;
- and
- a drain valve fluidly connected between the reservoir and the supply,
- wherein the drain valve is electronically controlled based on at least one of a sensed pressure of the reservoir, a temperature of reductant, and an engine operational status.
A method of dosing reductant into exhaust of an engine, comprising:
- drawing reductant from a low-pressure supply;
- pressurizing reductant;
- storing pressurized reductant;
- simultaneously injecting stored reductant at two locations into the exhaust;
- cooling the reductant at the two locations of injection;
- and
- selectively draining stored reductant in response to one of a reductant pressure, a reductant temperature, and an engine operational status,
- wherein selectively draining includes selectively draining stored reductant when the engine has been turned off and when the engine has been turned on.
Dependencies are inferred from the claim text.