Claims:CLAIMS
We Claim:

1. A supply module (100) for diesel exhaust fluid (DEF) tank (102) of an engine, comprising:
a filter assembly (108) integrated with the supply module (100) and adapted to filter the diesel exhaust fluid (DEF) in said diesel exhaust fluid (DEF) tank (102), wherein the filter assembly (108) further comprising;
a bottom filter (104) connected to the supply module (100) by means of welding; and
a top filter (106) aligned with said bottom filter (104) using alignment guide (105), said alignment guide (105) is part of the top filter (106).

2. The supply module (100) as claimed in claim 1, wherein the bottom filter (104) is welded with said supply module (100) by means of hot plate welding.

3. The supply module (100) as claimed in claim 1, wherein the bottom filter (104) is assembled with the supply module (100) by means of snap-fit or mechanical screws.

4. The supply module (100) as claimed in claim 1, wherein the top filter (106) is assembled with the bottom filter (104) by means of snap-fit or mechanical screws.

5. The supply module (100) as claimed in claim 1, wherein a fabric membrane (107) is welded with said top filter (106) and bottom filter (104).

6. The supply module (100) as claimed in claim 1, wherein the filter assembly (108) is composed of a material compatible with DEF applications.

7. The supply module (100) as claimed in claim 6, wherein the examples of the material compatible with DEF applications includes Nylon, HDPE, EPDM, Polypropylene, Polyethylene, and the like.

8. The supply module (100) as claimed in claim 1, wherein said top filter (106) and bottom filter (104) both will be acting as active or passive filter based on the dirt loading during the operation.
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention
[0001] Present invention relates to the field of fluid delivery systems in combustion engine of a vehicle. The invention relates in specific to improved filtration for a Diesel Exhaust Fluid (DEF) delivery system of a vehicle.

Background of the invention

[0002] Exhaust gas treatment for internal combustion engines are known in the prior arts. The exhaust gas treatment (EGT) systems are used to reduce the exhaust emissions coming out of the internal combustion engine. The EGT system of diesel engines typically reduces hydro carbons, carbon monoxide, nitrogen oxide (NOx) and particulate matter.

[0003] A dosing system is used for NOx reduction in the exhaust system. For reducing NOx an aqueous solution of urea is stored in a tank, from the tank this solution flows to the supply module via a filter. The supply module then supplies aqueous solution to the dosing module where aqueous solution of urea is injected into the exhaust stream. The filter that is located at inlet of supply module in DNOX dosing system is susceptible to clogging due to presence of impurities and the particles located in the flow paths of the dosing system. The clogging of filter reduces the ability of the dosing system to build pressure that is required for dosing of aqueous urea into the exhaust system.

[0004] Existing solutions for the above-mentioned problems includes Diesel Exhaust Fluid (DEF) 2-layer filtration concepts. However, conventional filtration systems, typically do not offer the filtration adequate enough for lifetime, for Off-highway applications where it needs to take more dirt load. Moreover, typical systems incorporate a control system for coordinating the injection of DEF with appropriate engine duty cycles so that the proper chemical reactions may take place. These problems are associated with the ambient air which has significant particulate contaminants of both a microscopic and macroscopic size. Existing systems does not take into account the particulates that may be drawn into the breather assembly and clog the hydrophobic membrane.

[0005] The prior art US9186632B2 discloses a diesel exhaust fluid (DEF) delivery system includes a tank for DEF, usually a urea aqueous solution, and a pump receiving the DEF from the tank for pressurization and delivery through a nozzle to the exhaust system of a work machine. A breather assembly is provided for the DEF tank and includes a housing having an inlet for ambient air and a particle filter adjacent the inlet for filtering particles. A hydrophobic membrane is interposed between the particle filter and an outlet leading to the tank for preventing outflow of DEF vapor and condensate.

Brief description of the accompanying drawing
[0006] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0007] Fig. 1 illustrates a supply module for exhaust fluid tank of an engine, in accordance with embodiments of the invention; and

[0008] Fig. 2 illustrates layout of a filter assembly of the supply module of Fig. 1, according to one embodiment of the invention.

Detailed description of the embodiments

[0009] FIG. 1 illustrates a supply module 100 for diesel exhaust fluid (DEF) tank 102 of an engine in a vehicle. In general, the DEF (or AdBlue) consists of 32.5% urea and 67.5% deionized water. The DEF or AdBlue is a liquid used to reduce the amount of nitrogen oxides (NOx) created by a diesel engine. The liquid is injected into the exhaust gas, which converts nitrogen oxides into harmless nitrogen and water. The DEF is consumed in selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in diesel exhaust emissions from a diesel engine.

[0010] The supply module 100 reduces the nitrogen oxides (Nox) in the exhaust system of the vehicle. The main function of the supply module 100 is to deliver the DEF from the tank 102 to the dosing module via a precise solenoid membrane pump. The supply module 100 is welded on bottom of the tank 102. The supply module 100 contains filter assembly 108 which filters the urea being pumped into the dosing module.

[0011] The filter assembly 108 which is integrated with the supply module 100 is adapted to filter exhaust fluid in the exhaust fluid tank 102. The filter assembly 100 easily mounted and designed to be installed in the supply module 100 for the tank 102. In one embodiment, the filter assembly may be composed of a material compatible with DEF applications. In this embodiment, the examples of the material may include Nylon, HDPE, EPDM, Polypropylene, Polyethylene, and the like. Each component of the filter assembly 108 is further described below.

[0012] The filter assembly 108 includes a bottom filter 104 and a top filter 106. The bottom filter 104 is connected to the supply module 100 by means of a welding. In one embodiment of the invention, the bottom filter 104 is welded with said supply module 100 by means of hot plate welding. In another embodiment, the bottom filter 104 is assembled with the supply module 100 by means of snap-fit or mechanical screws. Conventional supply modules in existing solutions generally have two layer filter for DEF filtration. In the proposed invention, the supply module 100 is having four layer filter for DEF filtration. Additional two layer filtration 106 is proposed on the conventional two layer filter 104.

[0013] The top filter 106 is aligned with the bottom filter 104 by using an alignment guide 105. Herein, the alignment guide 105 is a part of the top filter 106. In one embodiment, the top filter 106 is assembled with the bottom filter 104 by means of snap-fit or mechanical screws.

[0014] Fig. 2 illustrates functional layout of the filter assembly 108 of the supply module of Fig. 1. The filter assembly 108 is disposed in exhaust fluid (DEF) communication in the supply module 100. In one embodiment, on the intake side, the supply module 100 is equipped with the filter assembly 100. In operation, the DEF will be entering through both top filter housing 106a and bottom filter housing 104a and sent to pump module through the flow path 101 (shown in Fig. 2). Herein, the top filter housing 106a is acting as cover for the whole filter assembly 108. This top filter housing 106a itself acts cover as a suction area for the DEF or AdBlue. Further, the bottom filter 104 will pass the filtered DEF to the pump module of the DNOX system. In one embodiment, both top filter 106 and bottom filter 104 will be acting as active or passive filter based on the dirt loading during the operation.

[0015] In one embodiment, a fabric membrane 107 is welded with said top filter 106 and bottom filter 104. The supply module 100 ensures the right amount of DEF with its combination of diaphragm pump technology and actively switched solenoid valves, the supply module 100 provides precise, reliable DEF delivery. In one embodiment of the invention, the filter assembly 108 provides the diaphragm pump and valves with effective protection against contamination. This improves filtration requirements in the DEF tank 102 and enables reliable operation in off-highway applications.

It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.