Device for providing liquid reducing agent and motor vehicle having the device

Abstract

A device for providing liquid reducing agent for an exhaust-gas treatment device includes a tank and a delivery unit with an intake or suction point in the tank at which reducing agent can be suctioned or drawn out of the tank. The intake point is covered by a separation layer in such a way that a closed intermediate space is formed between the intake point and the separation layer. The separation layer has a higher flow resistance to reducing agent in an outflow direction from the intermediate space into the tank than in an inflow direction from the tank into the intermediate space. A motor vehicle having the device is also provided.

1 . A device for providing liquid reducing agent for an exhaust-gas treatment device, the device comprising:
 a tank;   a delivery unit having an intake point disposed in said tank and configured to draw-in reducing agent from said tank; and   a partition layer covering said intake point, forming a closed intermediate space between said intake point and said partition layer and defining an outflow direction from said intermediate space into said tank and an inflow direction from said tank into said intermediate space;   said partition layer having a higher flow resistance for reducing agent in said outflow direction than in said inflow direction.   
     
     
         2 . The device according to  claim 1 , wherein said partition layer is unidirectionally permeable to reducing agent in said inflow direction at least up to a threshold pressure difference of 0.01 bar to 0.1 bar between said tank and said intermediate space. 
     
     
         3 . The device according to  claim 1 , wherein said partition layer is a filter having at least one barrier ply increasing said flow resistance of said partition layer in said outflow direction. 
     
     
         4 . The device according to  claim 1 , wherein said partition layer is a screen having at least one flow-impeding device increasing said flow resistance of said partition layer in said outflow direction. 
     
     
         5 . The device according to  claim 1 , which further comprises a chamber disposed at least partially in said tank, said delivery unit being disposed in said chamber, and said partition layer surrounding said chamber and forming said intermediate space as an encircling intermediate space between said chamber and said partition layer. 
     
     
         6 . The device according to  claim 1 , which further comprises at least one guide structure disposed in said tank around said partition layer and configured to guide the reducing agent toward said partition layer. 
     
     
         7 . The device according to  claim 1 , wherein said partition layer is permeable to air bubbles in said outflow direction out of said intermediate space. 
     
     
         8 . The device according to  claim 1 , wherein said partition layer is configured to promote a flow of heat in said inflow direction and reduce a flow of heat in said outflow direction. 
     
     
         9 . The device according to  claim 1 , wherein said partition layer has a support structure imparting stability to said partition layer, and said support structure has a negligible flow resistance for reducing agent in said inflow direction and in said outflow direction. 
     
     
         10 . A motor vehicle, comprising:
 an internal combustion engine;   an exhaust-gas treatment device for purification of exhaust gases of said internal combustion engine; and   a device according to  claim 1  for supplying reducing agent to said exhaust-gas treatment device.