FILTERS

Filters Used In Gas Dehydration Process



Filters are installed in the glycol stream to remove solids and other contaminates which may cause plaguing and foams.
Types of Filter
Two types of filter commonly used as a gas dehydration system.
  • One type is used for solids removal.
  • Other for dissolved contaminants removal.
For solid removals fine stream shock type or cartridge filter (Nandpur Field) are used.
Now solved particles cause erosion of pump piston valve seals and plugging of equipment and foaming.

 Solid Removal (Cartridge or Shock Filters)
Shock filter are commonly used type of solid removal. Shock filter consist cylindrical elements that are replaced as they coated with solids. 
Differential Pressure Gauge
  • A difference pressure gauge measure pressure drop across the element a pressure drop of

3 to 6 psig 

(21 to 41 kpa)
is normal as glycol flow through the element the pressure drop increases as the element remove solid material and inversely become plugged. 

  • When pressure diffeerence becomes

15 to 20 psig 

(104 to 138 kpa)
The elements should be replaced to prevent stoppage of glycol flow and possible collapse of the elements.

 Dissolved Contaminant Removal (Activated Carbon Filters)
For removal of dissolved contaminates activated carbon filters used when the glycol contains measurable quantity of light hydrocarbons. The carbon filter must be change or reactivated frequently. Most glycol systems cannot be operated successfully with carbon absorption. 
Now the two types of activated carbon filters.
  • Small systems like one use a carbon canister with replaceable cartridges.
  • Large systems use loss fill carbon vessel that use granular activated carbon (Nandpur Field). 
When the loss fill vessel is used carbon particles sometimes called fines must be trapped to keep entering the glycol dehydration unit. This is especially important when a fresh carbon bed put into service. Any time the contaminant in the glycol increases. The carbon filter should be replaced. Monthly test should be run to determine the contamination level.



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