Claims:We Claimed:
1. A coalescing filter comprising:
a filter body (101) having inlet port and outlet port assembled with a filter bowl (102) using a sealing 'O' ring 1 (106);
a multilayer coalescing filter element (103) fastened 285 inside the filter bowl (102) aligned with the axis of filter body (101), sealed with sealing 'O' ring-2 (108) at the filter body (101) upper end and sealed with a rubber pad (107) at the bottom end;
a filter element disc (105) rested on the step provide on the inner diameter of the filter bowl (102); and
a removable drain plug (104) attached at the bottom of a drain chamber (109) below to the filter element disc (105).

2. The coalescing filter (100) according to claim 1, wherein the filter body (101) inlet port is connected to a CNG or LPG low pressure regulator.

3. The coalescing filter (100) according to claim 1, where in the filter body (101) outlet port is connected to a gas rail having injector.

4. The coalescing filter (100) according to claim 1, wherein the low-pressure regulator supply CNG or LPG to the inlet port of the filter body.

5. The coalescing filter (100) according to claim 1, wherein the sealing `O’ ring-1 (106) is made of a special rubber material that is compatible for CNG and LPG fuel.

6. The coalescing filter (100) according to claim 1, wherein the sealing `O’ ring-2 (108) is made of special rubber material that is compatible for CNG and LPG fuel

7. The coalescing filter (100) according to claim 1, wherein the rubber pad (107) is made of a special rubber material to meet requirement of CNG and LPG fuel.

8. The coalescing filter (100) according to claim 1, wherein the Filter element disc (105) is made up of a special metallic or nonmetallic material that provide greater strength and sustain load to meet requirement of CNG and LPG fuel.

9. The coalescing filter (100) according to claim 1, wherein the Filter element disc (105) has holes on its flat surface outside the perimeter of the coalescing filter elements.

10. The coalescing filter (100) according to claim 1, wherein drain chamber (109) is drainable.

11. The coalescing filter (100) according to claim 1, wherein drain plug (104) assembly is removable.

12. A coalescing filter comprising:
a cylindrical coalescing filter element (103) includes
a stainless-steel mesh;
a paper filter;
a felt filter; and
a perforated aluminium sheet coupled at specific distance using a clamping disc.

13. The coalescing filter (100) according to claim 12, wherein the stainless-steel mesh is at outer layer of the coalescing filter element.

14. The coalescing filter (100) according to claim 12, wherein the corrugated paper filter element is coupled inside the stainless-steel mesh by maintaining a fixed gap therein.
15. The coalescing filter (100) according to claim 12, wherein the felt filter placed next to the paper filter at a fixed gap therein. 16. The coalescing filter (100) according to claim 12, wherein the perforated aluminium sheet is the innermost layer of the coalescing filter element.
, Description:FILTER WITH CAOLESCING EFFECT

Field of the invention:

The present invention relates to a fuel filter system and more particularly it relates to fuel filter system suitable for a gaseous fuel such as CNG and LPG used in air cooled / water cooled engines / vehicles.

Background of the invention:

Coalescing is a technique used in filter media for the separation of liquid aerosols and droplets from a gas and coalescing filters are specifically designed to remove submicron oil, water and other liquid droplets from gaseous fuel flow. It is used for the removal of mist and foggy pollutants, irritants in natural gas vehicle filtration, compressed air filtration, compressed natural gas filtration, mist elimination and gas oil separation.
The liquid droplets in the airflow are removed through the coalescence process in which two or more liquid droplets come into contact with each other to overcome surface tensions of the droplets to coalesce.
To meet BSIV emission norms for carbureted vehicles using CNG and LPG fuel, following types of CNG and LPG kits are used:
1) CNG and LPG kit with Open Loop System
2) CNG and LPG kit with Closed Loop System
Considering the BSVI stringent emission norms for the Automobile vehicle, it is desirable to us CNG and LPG injection system. For these applications, a filter with coalescing effect is required for the oil free and clean CNG/ LPG supply to the injector of CNG / LPG fuel system to reduce the pollutant from the engine exhaust to meet BS VI norms.
A prior patent document 1149/MUMNP/2007 discloses a fuel filter system suitable for a liquid fuel such as diesel fuel, in which a particle filter is provided inside a housing. The fuel filter system comprising a filter housing, a particle filter disposed inside the housing, and a coalescer element for separation of water contained in the fuel by the particle filter. The invention discloses a fuel filter provided with a coalescer element is used to improve the elimination of water droplets. It does not provide coalescer for removal of dirt particles, burr, oil from CNG/ LPG fuel.
Another prior patent document IN201627018399 discloses a multistage fuel filter for cleaning of the fuel in the motor vehicle with a plurality of water separation stages. Filter elements can be replaced from filter housing. A coalescer medium and a particle filter medium are used as multistage fuel filter for separation of water from fuel. The invention discloses a fuel filter provided with two stage coalescer elements for removal of water droplets. It does not provide coalescer for removal of dirt particles, burr, oil from CNG/ LPG fuel. 1 The filter element may be used to filter a fluid comprising liquid and impurities. The filter is often used to remove water from a liquid fuel to avoid damage to moisture-sensitive components, such as fuel injection equipment. Improvements over the prior art of such liquid filter systems, especially fuel systems are desirable.
Hence, there is a need of filter that supply oil free and clean gas to the CNG and LPG injectors.
Objects of the invention:
1. An object of the present invention is to provide oil free and clean gas supply to the CNG and LPG injectors to meet stringent BSVI emission norms.
2. An object of the present invention to provide filter with coalescing effect that is suitable to drain impurities to avoid the clogging of the filter element and increase trouble free service life of the filter element.
3. Another object of the present invention to provide clean and oil free gas to the gas injector to maintain best performance of injector.
4. Yet another object of the invention to provide a filter with coalescing effect that has simple structural configuration.
5. One more object of the present invention is to provide a filter with coalescing effect that is cost effective.
6. Yet another object of the present invention is to provide very compact filter assembly.
7. Yet another object of the present invention is to provide a filter assembly with easy draining facility that maintains higher efficiency of the multi-layer filter element by draining the impurities.
8. One more object of the present invention is to provide an efficient and cost effective, easy to assemble, dissemble filter components.
Brief description of the drawings:
The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
FIG. 1 is a preferred embodiment of the filter with coalescing effects constructed in accordance with principles of this disclosure;
FIG. 2 is perspective view of the filter body of the filter with coalescing effect of FIG. 1;
FIG. 3 is a perspective view of the filter bowl of the filter with coalescing effect of FIG. 1;
FIG. 4 is a sectional view of the filter bowl of the filter with coalescing effect of FIG. 1;
FIG. 5 is a perspective view of the multilayer filter element of the filter with coalescing effect of FIG. 1;
FIG. 6 is an exploded view of the multilayer filter element of the filter with coalescing effect of FIG. 1;
FIG. 7 is a sectional view of the multilayer filter element of the filter with coalescing effect of FIG. 1;
FIG. 8 is a schematic of the layer 1 of the multilayer filter element of FIG. 7;
FIG. 9 is a schematic of the layer 2 of the multilayer filter element of FIG. 7;
FIG. 10 is a schematic of the layer 3 of the multilayer filter element of FIG. 7;
FIG. 11 is a schematic of the layer 4 of the multilayer filter element of FIG. 7;
FIG. 12 is an exploded view of the drain plug assembly (104) of the filter with coalescing effect of FIG. 1;
FIG. 13 is a sectional view of the drain chamber of the filter with coalescing effect of FIG. 1;
FIG. 14 is a perspective view of the sealing ‘O’ ring of the filter with coalescing effect of FIG. 1;
FIG. 15 is a perspective view of the sealing pad of the filter with coalescing effect of FIG. 1.

SUMMARY
The present invention relates to fuel filter system suitable for a gaseous fuel such as CNG and LPG used in air cooled / water cooled engines / vehicles.

According to an embodiment of the present invention, filter with coalescing effect (100) comprising a Filter Body (101) ; a Filter Bowl (102); a Multi layer coalescing filter element (103); a Drain Plug assembly (104); a Filter element disc (105); a Sealing `O’ Ring -1(106), a Rubber Pad (107), a Sealing `O’ Ring-2 (108) and a Drain Chamber (109). Filter with coalescing effect (100) is mounted to the frame of the vehicle by rigid or flexible mounts.
The Filter body (101) has an inlet and outlet connection. A low pressure regulator vents CNG or LPG gas to the filter body (101) through the inlet port. The outlet port of the filter body (101) is 3 connected to the gas rail having injector. The filter bowl (102) in assembled inside the filter body (101) using sealing ‘O’ ring-1 (106). The multi layer coalescing filter element (103) fastened inside the filter bowl (102) preferably axially symmetrically with respect to the longitudinal axis of the filter body (101) and filter bowl (102). The sealing `O ring-2(108) seals the multilayer filter element at filter body (101) end and another end seal with rubber pad (107) at the bottom side. The multi layer coalescing filter element (103) is rigid in construction.

The filter element disc (105) is rested at the outer portion edge of circumference of the filter bowl (102). Filter element disc (105) has holes on its perimeter. Porous filter element disc (105) allows to vent off gas impurity and separated oil particle from CNG/LPG fuel to bottom portion of the filter bowl (102) below the filter element disc (105). Gas impurities settles at downside (by gravity) of the filter element disc (105) and gathers in drain the chamber (109). Impurities from the drain chamber (109) can be drain out by removing drain plug assembly (104) periodically.

The sealing `O’ ring-1 (106) is for design to perfectly seal for filter body (101) and Filter bowl (102) in assemble condition. Filter bowl (102) fastened in the filter body (101) using sealing ‘O’ ring-1. Cylindrical multilayer coalescer fastened in the filter bowl (102) aligned longitudinal axis of the filter. The rubber pad (107) mounted at the center axis on filter element disc (105) at bottom and maintains the specific arrangement of the filter element layers at the top side by fixing them axially symmetrically with respect to the longitudinal axis of the filter body (101) and filter bowl (102).

The coalescing filter body inlet is connected to the outlet of a lower pressure regulator that allows to flow the gaseous fuel to the filter bowl chamber outside the filter elements. The gaseous fuel filtration executed by coalescing element when it passes from the coalescing filter elements to the inner chamber of the filter bowl.
The impurities like burr, dirt, dust, oil etc. get separated and drops to the down side of the filter element disc by force of gravity through the holes provided on the filter element disc gathers in the drain chamber (109). These impurities collected in the drain chamber (109) are to be drain by removing/replacing drain assembly periodically.

The multi layer coalescing filter element (103) comprises four layered coalescer for CNG and LPG fuel filtration. Coalescer filter element comprises Stainless steel wire mesh layer, paper filter layer in corrugated form which gives more effective area for filtration, felt filter layer and perforated aluminium sheet layer in tubical form, respectively arranged inside the filter bowl (102) using sealing ‘O’ ring mounted on the filter metal disc. Stainless steel wire mesh used for separating or filtering gases and separate out liquid, solid particles and burr etc. from the gaseous fuel. In disclosed invention, nearly micron size wire mesh used to separate liquids and gasses. The paper filter used next layer to the stainless-steel wire mesh of the coalescer filter element. Filter paper removes carbon particles, abrasive particles and other contaminants and tiny liquid particles from gaseous fuel i.e. CNG / LPG before it enters in injector of the injection system.

A Felt filter used next layer to the paper filter of the coalescer filter element. Felt filter layer removes oil & moisture contents and fine particles up to 0.01 micron. The cylindrical perforated aluminium sheet placed at the inner most layer of filter element. Perforated aluminium filter used to eliminate the impurity and foam mixed in the CNG/ LPG fuel.

Filter with coalescing effect (100) having multi layer filter element remove metallic burr, oil, water, burrs, dirt, particle from CNG/ LPG and supplies clean gas to the injectors of a gaseous fuel operated vehicle.

Detailed description of the invention:

The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto.

Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. In any embodiment described herein, the open-ended terms "comprising," "comprises,” and the like (which are synonymous with "including," "having” and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like. As used herein, the singular forms “a,” “an,” and “the” designate both the singular and the plural, unless expressly stated to designate the singular only. The present invention relates to a CNG/ LPG fuel system and more particularly it relates to CNG/ LPG pressure regulator system used in air cooled/ water cooled engines / vehicles.

The principles of this present invention have particular application to a Filter for the injector of CNG and LPG fuel system for compressed natural gas-powered vehicles, and thus will be described below chiefly in this context. It will of course be appreciated, and also understood, that principles of this invention may be applicable to other applications where it is desirable to regulate pressure filter gaseous media

Referring to the drawings, and initially to Figs. 1-2, a filter with coalescing effect (100) is illustrated generally at reference numeral 100. The filter with coalescing effect (100) includes a Filter Body (101), a Filter Bowl (102), a Multi layer coalescing filter element (103), a Drain Plug assembly (104), a Filter element disc (105), a Sealing `O’ Ring -1(106), a Rubber Pad (107), a Sealing `O’ Ring-2 (108) and a Drain Chamber (109).
Referring to FIG. 1, a filter with coalescing effect (100) is illustrated, including a CNG/ LPG low pressure regulator and CNG/LPG injector of the engine. Filter with coalescing effect (100) is mounted to the frame of the vehicle by rigid or flexible mounts. Filter with coalescing effect (100) comprises a filter body (101). The Filter body (101) has an inlet and an outlet connections, those are suitable for various internal diameters of the hoses.
A low pressure regulator supplies CNG or LPG gas to the filter body (101) through inlet port. The outlet port of the filter body (101) is connected to the gas rail having injector.
The filter bowl (102) in assembled inside the filter body (101) using sealing ‘O’ ring-1 (106).
The multi-layer coalescing filter element (103) fastened inside the filter bowl (102) preferably axially symmetrically with respect to the longitudinal axis of the filter body (101) and filter bowl (102). The sealing `O ring-2(108) seals the multilayer filter element at filter body (101) end and another end seal with rubber pad (107) at the bottom side. The multi-layer coalescing filter element (103) is rigid in construction.
The filter element disc (105) is rested on the step provide on the inner diameter of the filter bowl (102). Filter element disc (105) has holes on its flat surface outside the perimeter of the coalescing filter elements. Porous filter element disc (105) allows to vent off gas impurity and separated oil particle from CNG/LPG fuel to bottom portion of the filter bowl (102) below the filter element disc (105).
The impurities in the gaseous fuel settles at downside (by gravity) of the filter element disc (105) and gathers in the drain chamber (109). Impurities from the drain chamber (109) can be drain out by removing drain plug assembly (104) periodically.
Referring to FIG.1-3, cylindrical multilayer coalescer fastened aligned longitudinal axis of the filter. The coalescing filter has inlet and outlet for venting CNG at the other side of drain plug assembly (104). In the preferred embodiment of the invention, filter material of the components inlet and outlet placed at the upper portion of the filter body (101) as shown in FIG. 1. Inlet and outlet material may be steel, aluminum or non-metallic material compatible to the gaseous fuel that is passing through the coalescing filter element. Gas impurities drop downside by the gravity of the filter element disc (105) and gather in the drain chamber. These impurities collected in drain chamber (109) are to be drain by removing drain assembly periodically.
Filter bowl (102) fastened in the filter body (101) using sealing ‘O’ ring-1. A sealing `O’ ring-1 (106) is made of flexible material such as special rubber material that is compatible for CNG and LPG fuel. The sealing `O’ ring-1 (106) is for design to perfectly seal for filter body (101) and Filter bowl (102) in assemble condition.
The rubber pad (107) mounted at the center axis on filter element disc (105) at bottom and maintains the specific arrangement of the filter element layers at the top side by fixing them axially symmetrically with respect to the longitudinal axis of the filter body (101) and filter bowl (102). The rubber pad is made of flexible material such as special rubber material that is compatible for CNG and LPG fuel.
Referring to FIG. 6, the multi-layer coalescing filter element (103) comprises four layered coalescer for CNG and LPG fuel filtration. The Coalescer filter element comprises Stainless steel wire mesh layer, paper filter layer, felt filter layer and perforated aluminium sheet layer, respectively arranged inside the filter bowl (102) using sealing ‘O’ ring mounted on the filter metal disc.
The stainless-steel mesh is at the outermost layer. Stainless steel wire mesh used for separating or filtering gaseous fuel from solid impurities. In disclosed invention, nearly micron size wire mesh used to separate liquids and gasses. Stainless steel wire mesh screen is resistant to pitting by solutions containing chloride ions, phosphoric acid, sulfuric acid, and brine solutions.
Referring to FIG. 1, FIG. 5, FIG. 6, paper filter layer placed next layer to the stainless-steel wire mesh of the coalescer filter element. Filter paper remove carbon, abrasive and other contaminants from CNG/ LPG before it enters injector of the engine injector system. The filter paper does not allow the very fine dust particles get inside the engine, which can damage cylinder walls, pistons and piston rings.
Referring to FIG. 1, FIG. 6, FIG. 9, felt filter layer placed next to layer to paper filter of the coalescer filter element. Felt is a cloth type material that is produced by condensing, matting and pressing fibers. Disclosed invention uses felt filter that is soft, course texture and tough enough to form construction materials. Used Felt materials filters are very versatile and cost effective. It has very low density, weight and good permeability, good fluid flow capacity or rates and can capture large amounts of debris. Here, Felt filter layer capable of filtering particles from 1 to 200 of microns, has chemical compatibility, High flow - low pressure drop. Felt filter layer removes oil & moisture contents and fine particles up to 0.01 micron.
Referring to FIG. 1; FIG. 6; FIG. 9, disclosed invention uses cylindrical perforated aluminium sheet at the inner most layer of filter element. It might be made of stainless steel, carbon steel, aluminum or copper sheet and the hole shape might be round or square. Perforated aluminium filter has accurate filtration rate, high mechanical strength and it filters a large variety of fluids and retain almost any size solids. Here, perforated aluminium filter used to eliminate the impurity and foam mixed in the CNG/ LPF fuel. Due to high porosity and excellent permeability, Corrosion resistance and high temperature resistance, Firm structure and Accurate filtration precision Perforated aluminium filter preferred to use as the inner layer of the filter element to give rigid support to the coalescing filter element.
Filter with coalescing effect (100) having multi-layer filter element remove metallic burr, oil, water, dirt, particle from CNG/ LPG and supplies clean gas to the injectors of a gaseous fuel operated vehicle.
Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a "means") used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.