Process and apparatus for separating out and removing water present in liquid fuels, especially water from diesel oil

Abstract

A apparatus separates out and removes water present in liquid fuels. The fuel supplies an internal combustion engine by a fuel delivery pump ( 12 ). Water is separated out at a filter ( 5 ) having a collecting space ( 27 ) for collecting separated water and connected upstream of the suction side ( 11 ) of the fuel delivery pump ( 12 ). The pump suction action counteracts outflow of water from the collecting space ( 27 ). Depending on the amount of water collected, the pump suction action is negated, and an outlet valve at an outflow orifice ( 37 ) of the collecting space ( 27 ) is opened by a discharge ( 43, 53 ) producing a pressure gradient enabling the discharge of water from the collecting space ( 27 ) over a discharge period when the fuel delivery pump ( 12 ) is operating.

What is claimed is: 
     
         1 . An apparatus for separating and removing water in liquid fuels, comprising:
 a filter having a water separator, a filter inlet, filter outlet and a collecting space with an outflow orifice for collecting separated water;   a fuel tank in fluid communication with said filter inlet through a line system;   a fuel delivery pump of a fuel supply system for an internal combustion engine having a suction side connected in fluid communication with said filter outlet and a pressure side;   a discharge having a pressure control for producing a pressure gradient at said outflow orifice to enable outflow of the separated water against a suction action of said fuel delivery pump at said filter during discharge intervals, said pressure control having a valve and a hydropneumatic accumulator with an oil side connected in fluid communication with said pressure side of said fluid delivery pump, said valve being connected to said filter inlet and said hydropneumatic accumulator to control fluid communication of said hydropneumatic accumulator with said filter;   a water amount sensor in said collecting space for detecting amounts of the separated water collected in said collecting space and producing water amount signals representative of the amounts detected; and   control electronics connected to said discharge and to said water amount sensor for receiving and processing the water amount signals and producing control signals and transmitting the control signals to said discharge to control said valve to control fluid communication between said filter and said hydropneumatic accumulator.   
     
     
         2 . An apparatus according to  claim 1  wherein
 said hydropneumatic accumulator is a diaphragm accumulator. 
 
     
     
         3 . An apparatus according to  claim 1  wherein
 said valve is a 3/2-way valve coupled to said fuel tank, alternatively connecting said filter inlet in fluid communication with said hydropneumatic accumulator and with said fuel tank. 
 
     
     
         4 . An apparatus according to  claim 1  wherein
 a retrofit system attaches said discharge, said water sensor and said control electronics to an existing filter with a water separator. 
 
     
     
         5 . An apparatus according to  claim 4  wherein
 said filter is a spin-on filter element and has a filter casing with a water outlet on a bottom thereof; and 
 said retrofit system includes a body attached to said bottom and includes a casing surrounding said water outlet of said filter casing and forming a component of said collecting space. 
 
     
     
         6 . An apparatus according to  claim 5  wherein
 said body is attached to said casing by a hollow screw threadedly connected to said water outlet and having holes forming a water passage to said cavity. 
 
     
     
         7 . An apparatus according to  claim 6  wherein
 said body receives said water amount sensor, said control electronics and said valve therein.