Aerial Valerus Compressors

Aerial Valerus Compressors

(K1301-K1314)

 

Company Name Equipment Name  Area of Machine Equipment ID
OGDCL Aerial Valerus Compressors Front End Compression Plant (FECP) JGT/4
 

 

 

 

 

Compressor

 

Compressor Type Positive Displacement Compressors
Compressor Rated RPM 750 rpm – 1500 rpm
No. of Cylinders 4
Compressor Support 4
Compressor Rated Power 2600 Horse power (1939 Kw)

 

Inlet Separator

Gas is distributed in two inlet separators that are installed in parallel fashion. Gas enters from the bottom and is allowed to expand in the separator. The separator is provided with a demister pad and the gas moves up passing through this demister pad so if any liquid or mist is present it gets separated. A level gauge is installed to check the level of liquid in the separator. The liquid is moves to liquid handling area while gas moves up for further processing. Pressure drop across the separators is very low and change in temperature of gas is also negligible. A level of 25-30% is maintained to avoid the passing of gas along with the liquid. Gas from the inlet separator moves to the pre-cooler for cooling.

 

Inlet Pressure Outlet Pressure Inlet Temperature Outlet Temperature In Flow rate of gas Out Flow rate of gas
717 psig 716 psig 110 F 110 F 350-360 MMSCFD 350-360 MMSCDF

 

Pre-Cooler

 

Two pre-coolers are installed in parallel fashion. Pre-coolers are 1-1 pass shell and tube heat exchanger. Raw gas from the inlet separators enters the tube side of the heat exchangers. After being counter currently cooled it moves to the next unit. Sale gas from the primary membranes is used as cooling medium on the shell side. Discharge of the tube side of both the pre-cooler enters the common line through which it moves in the economizers.

Sale gas being clean is used on the shell side while raw gas is used on tube side so that if dirt accumulates tubes being cheaper could be replaced.

 

Tube side Inlet Temperature Shell side Inlet Temperature Tube side Outlet Temperature Shell side Outlet Temperature
110 F 60 F 90-95 F 85-90 F

 

Economizer

 

Raw gas is further cooled in two economizers. Raw gas is entered in the tubes of 1-1 counter current shell and tube heat exchanger (Economizer). Two pre-coolers of same capacity are installed in parallel fashion. Dry gas from the filter coalescer enter the shell side of the exchanger as the cooling medium that’s why it is known as economizer. From the tube side of both economizers raw gas move towards the chiller through common discharge line of the exchanger for further cooling.

Dry gas being clean after passing through filter coalescer is used on the shell side while raw gas is used on tube side so that if dirt accumulates tubes being cheaper could be replaced.

 

Tube side Inlet Temperature Shell side Inlet Temperature Tube side Outlet Temperature Shell side Outlet Temperature
90-95 F 60 F 74-78 F 75 F

 

 

 

 

 

 

Chiller

 

This is a kettle type heat exchanger. From refrigeration unit point of view it is the evaporator of the refrigerant. 2-phase propane a refrigerant enters the shell side and leaves as vapors taking heat of refrigeration from the gas in the tube side. Raw gas enters the tube side and is cooled down up to the temperature required in the filter coalescer. Shell side fluid will be further discussed in the refrigeration unit of the plant. From the tube side cool gas will move to the filter coalescer for cleaning and drying purpose.

 

Tube side Inlet Temperature Shell side Inlet Temperature Tube side Outlet Temperature Shell side Outlet Temperature
74-78 F 55-60 F 60 F 55-60 F

 

Filter Coalescer

 

This is a separating vertical vessel. This vessel is divided in two chambers. The lower chamber has a demister pad and a liquid level is maintained as a seal to avoid the leaking of gas along with the settling liquid. Raw gas is at a high pressure and is cooled to a low temperature. All the heavier hydrocarbons and water vapors in the gas will condense under these conditions and on entering in the lower chamber liquid will settle down as droplets and mist present in the liquid will be removed while passing through the demister pad. Above the demister pad there is a plate which separates the two vessels. This plate has holes on which special filters are placed. Gas through these holes will pass through the filters. On passing through these filters left over liquid will remain in the filters and gas will move up in the vessel and leaves from the top. As the filters get wet with the liquid, they will start dripping and the liquid will accumulate on the plate. A level of liquid will also be maintained on this plate for sealing purpose. Liquid will be drained from the vessel from two points; above the plate of the filters and from the bottom of vessel. Most of the liquid is removed in filter coalescer. Now this cool gas is passed from the shell side of the economizer to cool the incoming raw gas. Two level gauges are mounted to check the level of liquid in the vessel.

To remove all the liquid and to dry it properly it is required to further process the gas as if any liquid or heavier hydrocarbon enter the membrane unit if can condense and can damage cellulose acetate membrane. For this Mem Guard unit is installed.

 

Mem Guard Unit

on next post

About Admin

Leave a Reply

Your email address will not be published. Required fields are marked *