FILTER SEPARATORS / COALESCERS

 

Engineering Technology, Inc. (ETI) provides treatment systems to process and remove particulates and liquids from gas streams. The process equipment consists of standalone vessels or skid-mounted modules. 

 

The components of a filter separator/coalescer require a vessel to house the filter elements, a quick opening closure, the filter elements and mist extraction. The differences between whether a filter is a separator or a coalescer depends upon the direction of gas flow through the filter elements and the presence of pre- or post-mist elimination devices. Mist elimination devices are principally: vane sections, double pocket vane or single vane packs or mesh pads or combo-vane-mesh packs.

 

REASONS FOR A FILTER SEPARATOR OR FILTER COALESCER

The principal contaminants removed in filter separators are solid particulates, mill scales, rust, dust, formation fines, corrosion by-products, paraffins, asphaltenes, and small amounts of liquid condensates. The principal liquid contaminants removed in coalescing filters are water, hydrocarbons, and compressor lube oils. The principle solid contaminants removed in filter separators are mill scales, rust, dust, formation fines, corrosion by-products, paraffins and asphaltenes. In each filter vessel there are five basic features: primary separation, filtration, secondary separation, mist extractor, controlled liquid discharge. A horizontal double barrel filter separator and a vertical filter coalescer are illustrated below. Dry gas filters do not have a liquid discharge.

 

	PRIMARY SEPARATION	FILTRATION ELEMENT	SECONDARY SEPARATION	MIST EXTRACTOR	CONTROLLED DISCHARGE
DBFS	INLET SECTION	OUTSIDE-IN FLOW	COALESCING SECTION	VANE/MESH	TWO DUMPS
VFC	LOWER KO DRUM	INSIDE-OUT FLOW	BELOW ELEMENTS	VANE BOTTOM SECTION	TWO DUMPS

 

In both of these examples, the vessel could just as likely been configured vertically or horizontally.  When arranged vertically, the flow enters the bottom KO section where free liquids/slugs separate; when arranged horizontally, flow enters the standoff gas distributors where free liquids/slugs accumulate and drain to a lower-smaller barrel.  In horizontal configurations, large slugs of liquids require sizing the lower barrel for the size of the slug.

The particulate removal can be from 0.3 micron to 5 microns. Liquid droplet removal requires coalescing the liquid prior to separation.