Reductant insertion assembly comprising a bladder

An aftertreatment system for use with an engine producing an exhaust gas, the aftertreatment system comprising:

• a selective catalytic reduction system configured to decompose constituents of the exhaust gas;
• and
• a reductant insertion assembly fluidly coupled to the selective catalytic reduction system and configured to insert a reductant therein, the reductant insertion assembly comprising:
• a reductant bladder defining a bladder internal volume for holding a reductant, the reductant bladder comprising a bladder inlet and a bladder outlet,
• a pressure sensor positioned downstream of the bladder outlet, the pressure sensor operable to sense a pressure of the reductant downstream of the reductant bladder, and generate a pressure signal indicative of the pressure, and
• a compression mechanism operably coupled to the reductant bladder, the compression mechanism configured to selectively exert a compressive force on the reductant bladder so as to expel the reductant therefrom via the bladder outlet, the compression mechanism exerting the compressive force in response to the pressure signal.

A method of delivering a reductant to an aftertreatment system from a reductant insertion assembly, the reductant assembly comprising a reductant bladder, the method comprising:

• determining, at a controller, by a pressure sensor positioned downstream of a bladder outlet of the reductant bladder, a pressure of a reductant downstream of the reductant bladder in a reductant delivery line fluidly coupled to the bladder outlet of the reductant bladder;
• determining, at the controller, if the pressure is less than a predetermined low pressure threshold;
• and
• in response to the pressure being less than the predetermined low pressure threshold, causing, by the controller, exertion of a compressive force on the reductant bladder so as to increase a pressure of the reductant in the reductant delivery line.