Substance dispenser for treating exhaust gas and method

Abstract

A reservoir ( 120 ) for storing an additive solution includes a reservoir volume ( 128 ) formed internally to the reservoir ( 120 ). The reservoir volume ( 128 ) is arranged to sealably store the additive solution. An inlet passage ( 122 ) is in fluid communication with the reservoir volume ( 128 ). A canister ( 140 ) is disposed on the reservoir ( 120 ). The canister ( 120, 300 ) includes a cup portion ( 308 ) that forms an internal volume having a permeable portion ( 314 ), and a head portion ( 316 ) connected to the cup portion ( 308 ). A plurality of pellets ( 310 ) is disposed in the internal volume of the cup portion ( 308 ) of the canister, such that a fluid ( 306 ) contained in the reservoir volume ( 304 ) is in fluid communication with the plurality of pellets ( 310 ) through the permeable portion ( 308 ) of the canister.

1 . A reservoir for storing an additive solution, the reservoir comprising:
 a reservoir volume formed internally to the reservoir, wherein the reservoir volume is arranged to sealably store an additive solution;   an inlet passage in fluid communication with the reservoir volume;   a canister disposed on the reservoir, wherein the canister comprises:
 a cup portion that forms an internal volume, the internal volume comprising a permeable portion, and 
 a head portion connected to the cup portion; 
   a plurality of pellets disposed in the canister, wherein the plurality of pellets is disposed in the internal volume of the cup portion of the canister;   
     wherein a fluid contained in the reservoir volume is in fluid communication with the plurality of pellets through the permeable portion of the canister. 
   
   
       2 . The reservoir of  claim 1 , wherein the fluid contained in the reservoir volume is an aqueous solution containing urea. 
   
   
       3 . The reservoir of  claim 1 , wherein the plurality of pellets contain urea in a solid form, and a binder that is water soluble. 
   
   
       4 . The reservoir of  claim 1 , wherein the canister is at least partially disposed within the reservoir volume, and wherein the permeable portion of the canister is submerged in the fluid contained in the reservoir volume. 
   
   
       5 . The reservoir of  claim 1 , further comprising a doser operably connected to the reservoir, wherein the doser is in fluid communication with the reservoir volume and capable of admitting at least some of the fluid contained therein. 
   
   
       6 . The reservoir of  claim 1 , further comprising a concentration sensor disposed in fluid communication with the reservoir volume, wherein the concentration sensor is capable of sensing a concentration of additive in the fluid. 
   
   
       7 . The reservoir of  claim 1 , further comprising a fluid heater disposed in fluid communication with the reservoir volume. 
   
   
       8 . A vehicle having an internal combustion engine associated therewith, the internal combustion engine having an exhaust port connected to an exhaust pipe, the exhaust pipe mounted to the vehicle and containing at least one after-treatment device, the vehicle comprising:
 a storage reservoir for an additive solution, the storage reservoir comprising:
 an internal reservoir volume arranged to retain a quantity of the additive solution, 
 a canister containing an amount of an additive in solid form, 
 an inlet passage containing a filter, the inlet passage being in fluid communication with the reservoir volume and arranged for providing a filling passage for adding a liquid to the reservoir volume, 
 a concentration sensor arranged to sense an additive concentration of the additive solution, and 
 a doser operably associated with the storage reservoir and arranged to admit a predetermined portion of the additive solution; 
   a conduit fluidly connecting the doser with an injector, wherein the injector is operably associated with the exhaust pipe, wherein the injector is disposed upstream of the at least one after-treatment device; and   a control module operably associated with the internal combustion engine, the concentration sensor, and the doser.   
   
   
       9 . The vehicle of  claim 8 , wherein the canister comprises a permeable portion, and wherein the additive in solid form fluidly communicates with the additive solution through the permeable portion. 
   
   
       10 . The vehicle of  claim 8 , wherein the permeable portion comprises a lateral wall enclosing an internal canister volume, wherein the additive in solid form is disposed in the internal canister volume, and wherein the lateral wall forms a plurality of openings that fluidly connect the internal canister volume with the internal reservoir volume. 
   
   
       11 . The vehicle of  claim 8 , wherein the canister comprises a head that sealably connects to an external wall of the reservoir, wherein the canister is insertable into the reservoir volume through an opening formed in the external wall of the reservoir. 
   
   
       12 . A method for providing an additive to an injection device disposed within an exhaust stream, comprising the steps of:
 storing an additive solution in a storage reservoir;   deciding in a control module to dispense a desired amount of the additive into the exhaust stream;   determining a concentration of the additive in the additive solution with the control module;   at times when the concentration of the additive in the additive solution is within an acceptable range, calculating a desired volume of the additive solution to be injected based the concentration of the additive in the additive solution;   dosing the desired volume with a doser; and   injecting the desired volume of the additive solution into the exhaust stream with the injection device.   
   
   
       13 . The method of  claim 12 , wherein the determination step is accomplished by a modeling calculation that is based on an original amount of a solvent added to the storage reservoir minus a used amount of additive solution dispensed since a time of last replenishment. 
   
   
       14 . The method of  claim 12 , wherein the determination step is accomplished by a measurement of the concentration with a concentration sensor, and wherein the method further comprises the step of communicating an output of the sensor to the control module. 
   
   
       15 . The method of  claim 12 , further comprising the step of providing a notification to an operator that replenishment of the storage reservoir is required at times when a determination is made at the determination step that the concentration of the additive in the additive solution is outside of the acceptable range. 
   
   
       16 . The method of  claim 15 , further comprising the step of replacing an additive-containing canister that is associated with the storage reservoir. 
   
   
       17 . The method of  claim 15 , further comprising the step of adding an amount of solvent into the storage reservoir. 
   
   
       18 . The method of  claim 12 , wherein the calculation step is essentially accomplished in the control module by dividing a desired mass of additive by the determined concentration of the additive solution. 
   
   
       19 . The method of  claim 12 , further comprising the step of measuring a flow rate of additive solution through the doser.