CLIAMS:We claim:
1. A combined compressor assembly for raw as well as refined biogas comprising:
a two-staged compressor, wherein the first two stages compresses the raw biogas;
a three staged booster, wherein the three staged booster is connected to the second stage compressor via a refinement plant, wherein the three staged booster boosts a pressure of compressed refined biogas manifold;
a crankcase;
a crankshaft assembly;
a plurality of connecting rods, wherein the crankcase, the crankshaft assembly and the connecting rods are combined for two stage raw bio gas compressor & three stage refined biogas booster compressor, wherein one end of the connecting rod is connected to the crankshaft through a crankshaft bearing and another end to a first and second stage pistons through a gudgeon pin and a connecting rod bearing;
a plurality of cylinders, wherein a first compressor stages comprise two cylinders and piston assembly and the rest of the stages comprise one cylinder and one piston for each compressor stage, wherein a reciprocating movement of the piston compresses the raw and refined biogas, wherein the reciprocating movement is provided through a rotating movement of the crankshaft;
a suction and a delivery valve assembly for each compressor stage, wherein the suction valve assembly sucks the biogas inwards to the compressor, wherein the delivery valve transfers the compressed biogas outwards from the compressor stages;
a plurality of scraper rings, wherein the scraper rings help to remove the oil from first and second stage cylinders;
a flywheel, wherein the flywheel is connected to the crankshaft through a flywheel adapter;
a fan drive assembly comprising a fan, wherein the fan drive assembly is provided in a compressor housing;
an air-cooled inter-cooler and after-cooler for each compressor stage, wherein the inter-cooler and after–cooler are connected to the plurality of cylinders and a plurality of purge bottles, wherein one purge bottle is provided for each compressor stage, wherein the purge bottle provides a moisture extraction from the compressed and cooled biogas;
a lubricator for lubrication of compressor assembly;
a manual condensate drain system for drain separation;
a plurality of interconnecting pipelines, wherein the plurality of interconnecting pipelines connect all the pneumatic components;
a safety system to ensure regular functioning of the compressor assembly.

2. The compressor assembly as claimed in claim 1, wherein the plurality of boosters increases a pressure of the refined biogas upto 250 .

3. The compressor assembly as claimed in claim 1, wherein the plurality of boosters allows a flow rate capacity of the refined biogas upto 40
4. The compressor assembly as claimed in claim 1, wherein the raw biogas as a working medium comprises and , wherein the raw biogas is 100% saturated and free from Hydrogen Sulfide

5. The compressor assembly as claimed in claim 1, wherein the refined biogas as a working medium comprises , and , wherein the refined biogas is water saturated and free from Hydrogen Sulfide

6. The compressor assembly as claimed in claim 1 is arranged in a tandem mode. ,TagSPECI:A) TECHNICAL FIELD OF INVENTION
[001] The present invention generally relates to a mechanical equipment and particularly relates to a compressor unit. The present invention more particularly relates to a combined compressor for compressing raw biogas and boosting pressure of refined biogas.

B) BACKGROUND OF THE INVENTION
[002] A biogas compressor is a machine that increases the pressure of a gas or vapour by increasing the gas density and delivering the fluid against the connected system resistance. The biogas compressors are implemented in household and commercial purposes in which the biogas is produced from waste or stale food, waste flour, wet waste in house, edible and non-edible seeds. The gases like methane (CH4) and carbon dioxide (CO2) are separated from a raw biogas. The refined biogas is then compressed and filled in separate cylinders.
[003] One of the prior arts discloses a mobile biogas processing system that includes a mobile platform, a compressor physically coupled to the mobile platform, a pump physically coupled to the mobile platform and having a water input and a water output, and scrubber tower physically coupled to the mobile platform and having input connected to the compressor and water pump. In examples, the mobile platform is a skid or a combination of skids, a trailer, or a shipping container. An exemplary method of using a mobile biogas processing system includes coupling a first biogas compressor, first scrubber, second scrubber, and flash tank to a mobile platform and delivering the platform and system components to a biogas site. In an example, the system includes its own water supply and burns biogas or crude methane to power pumps, compressors, and other components.
[004] Although the prior arts disclose various techniques of biogas compression but are limited in the sense of working fluid i.e. the prior art biogas compressor either uses a raw biogas or refined biogas as working fluid. This limits an application area of the biogas compressor.
[005] In the view of foregoing, there is a need for a universal biogas compressor that provides combined facility for compressing raw bio gas as well as boosting the refined biogas.
[006] The above mentioned shortcomings, disadvantages and problems are addressed herein, as detailed below.

C) OBJECTS OF THE INVENTION
[007] The primary object of the present invention is to provide a biogas compressor having combined facility for compressing raw bio gas as well as boosting the refined biogas.
[008] Another object of the present invention is to provide a biogas compressor with compact design achieved through a tandem arrangement.
[009] These and other objects and advantages of the embodiments herein will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

D) SUMMARY OF THE INVENTION
[0010] The various embodiments of the present invention disclose a combined biogas compressor assembly for raw as well as refined biogas. The compressor assembly comprises a two-staged compressor and a three staged booster. The two-staged compressor and a three staged booster comprises a crankcase, a crankshaft, a connecting rods, a plurality of pistons, a plurality of cylinders, a suction and a delivery valve assembly for each compressor stage, a plurality of scraper rings for first and second compressor stage, a flywheel, a fan drive assembly comprising fan, an air-cooled inter-cooler and after-cooler for each compressor stage, a lubricator for lubrication of compressor assembly, a manual condensate drain system for drain separation, a plurality of interconnecting pipelines and a safety system. The first two stages compress the raw biogas. The three staged booster is connected to the second stage compressor via a refinement plant. The three staged booster boosts a pressure of compressed refined biogas. The crankcase, crankshaft assembly & connecting rods are combined for two stage raw bio gas compressor and three stage refined bio-gas booster compressor. One end of the connecting rod is connected to the crankshaft through the crankshaft bearing and another end to a first and second stage piston through a gudgeon pin and the connecting rod bearing. The first compression stage comprises two cylinders and piston assembly and rest of the stages are comprises one cylinder and one piston for each compressor stage. Each cylinder houses a piston and a reciprocating movement of the piston compresses the raw and refined biogas. The reciprocating movement is provided through a rotating movement of the crankshaft. The suction valve assembly sucks the biogas inwards to the compressor. The delivery valve transfers the compressed biogas outwards from the compressor stages. The plurality of scraper rings helps to remove the oil from first and second stage cylinders so that minimum oil to be carried out with gas, while delivering from cylinder. The flywheel is connected to the crankshaft through a flywheel adapter. The fan drive arrangement is provided in a compressor assembly as an integral part of it. The inter-cooler and after–cooler are connected to the plurality of cylinders and a plurality of purge bottles. One purge bottle is provided for each compressor stage and provides a moisture extraction from the compressed and cooled biogas. The plurality of interconnecting pipelines connects all the pneumatic components. The safety system ensures regular functioning of the compressor assembly.
[0011] According to one embodiment herein, the plurality of boosters increases a pressure of the refined biogas upto 250 .
[0012] According to one embodiment herein, the plurality of boosters allows a flow rate capacity of the refined biogas upto 40 .
[0013] According to one embodiment herein, the raw biogas as a working medium comprises and . The raw biogas is 100% saturated and free from Hydrogen Sulfide
[0014] According to one embodiment herein, the refined biogas as a working medium comprises , and , wherein the refined biogas is water saturated and free from Hydrogen Sulfide
[0015] According to one embodiment herein, the compressor assembly is arranged in a tandem mode.
[0016] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

E) BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0018] FIG. 1A illustrates a schematic diagram of the biogas compressor and FIG. 1B illustrates a connectivity of a lubrication system, according to one embodiment of the present invention.
[0019] FIG. 2A illustrates a top view and FIG. 2B illustrates a front view of the biogas compressor, according to one embodiment of the present invention.

F) DETAILED DESCRIPTION OF DRAWINGS
[0020] FIG. 1A illustrates a schematic diagram of the combined biogas compressor and FIG. 1B illustrates a connectivity of a lubricator, according to one embodiment of the present invention. With respect to FIG. 1A, the biogas compressor assembly comprises a common header for suction 101 connected to the first stage compressor cylinders 102. The first stage cylinders are mounted on the crankcase and further to the intercoolers 105. The intercooler 105 cools the raw biogas collected from the first stage compressor cylinders and transfers it to the purge bottle 103 for moisture extraction. The extracted moisture content is drained out through the drain valves. The raw biogas is then admitted to the second stage compressor cylinder 104 (which is also mounted on the crankcase) and repeats the first stage procedures upto the purge bottle 103. After second stage compression, the compressed biogas is refined in a biogas refinery plant 109 and then transferred to the three staged booster compressor 107. The three stages of booster compressor 107 compresses the biogas to a high pressure value of 250 . The compressed biogas from the third stage booster compressor 107 is passed to the after-cooler 108 where the compressed biogas is cooled and is delivered into the purge bottle for extraction of moisture content present in it. The compressed biogas is then transferred to a gas distribution vessel 110. The heat extracted by the inter-coolers 105 and after-cooler 108 is dissipated to the atmosphere.
[0021] With respect to FIG. 1B, first 102 and second 104 stage, both are lubricating by splash lubrication and three staged booster compressor 107 is connected to the lubricator 112 through a non-return valve 111. The lubrication lubricator 112 maintains lubrication in the compressor assembly to reduce friction, heat generation and wearing of the compressor assembly during its working.
[0022] FIG. 2A illustrates a top view and FIG. 2B illustrates a front view of the biogas compressor, according to one embodiment of the present invention. With respect to FIG. 2A, the raw biogas is compressed into the first and second stages of the compressor through the assistance of a drive motor. The drive motor also rotates the crankshaft that is connected to the compressor and booster stages. An inter-cooler channelling is provided between two successive compressor and booster stages to dissipate the heat generated due to the compression. A oil recovery vessel is provided for collection of residual oil recovered after lubrication. The suction of the raw gas, delivery of the refined biogas from the plant and delivery of high pressure biogas outwards from the compressor assembly is managed by a gas distribution panel.
[0023] With respect to FIG. 2B, a suction header for raw biogas, an electric control panel and base frame is visible.
[0024] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. The embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

G) ADVANTAGES OF THE INVENTION
[0025] The present invention supplies a high pressure biogas and provides a combined compressor facility for both raw and refined biogas. The compressor assembly in the present invention is highly compact due to its design in tandem arrangement.
[0026] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the claims.