Breather pipe structure for liquid reducing agent storage tank

Abstract

Provided is a breather pipe structure for a liquid reducing agent storage tank which is capable of introducing/discharging air according to changes of liquid amount in the liquid reducing agent storage tank and capable of controlling the full-tank liquid surface level during injection of a liquid reductant. In the breather pipe structure for a liquid reducing agent storage tank ( 10 ) which stores a liquid reducing agent ( 5 ) and which has a breather pipe ( 20 ) attached on top of the tank for introducing/discharging air, a lower end ( 20 c ) of the breather pipe ( 20 ) extending downward from the top of the liquid reducing agent storage tank ( 10 ) is positioned at a level corresponding to the liquid surface level when the tank is full.

1 . A breather pipe structure for a liquid reducing agent storage tank which stores a liquid reducing agent and which has a breather pipe for introducing/discharging air attached on top of the liquid reducing agent storage tank, wherein
 a lower end of the breather pipe extending downward from the top of the liquid reducing agent storage tank is positioned at a level corresponding to a level of the liquid surface when the tank is full.   
     
     
         2 . The breather pipe structure for a liquid reducing agent storage tank according to  claim 1 , wherein
 the liquid reducing agent storage tank has a filler pipe arranged on its upper edge so as to extend obliquely upward, and   the lower end of the breather pipe is positioned above a lower open end of the filler pipe and below an upper-end inlet of the filler pipe.   
     
     
         3 . The breather pipe structure for a liquid reducing agent storage tank according to  claim 1 , wherein the breather pipe is formed to have an inner diameter that is sufficiently smaller than the inner diameter of the filler pipe. 
     
     
         4 . The breather pipe structure for a liquid reducing agent storage tank according to  claim 3 , wherein a lower part of the breather pipe extends vertically from the topwall of the liquid reducing agent storage tank to the inside of the tank while an upper part of the breather pipe extends vertically upward from the topwall of the liquid reducing agent storage tank and then is bent horizontally, and the front end of the breather pipe is open to the atmosphere.