GAS FILTER SEPARATORS

Tresca’s range of Gas Filter Separators are used to remove solid impurities and liquids out of natural gas streams. Through our three stage separation system, these filter separators provide an effective, efficient and low cost gas purification solution.

Stage 1: Gravity separation due to gas velocity reduction upon vessel entry.
Stage 2: Filter Separator Elements.
Stage 3: Stainless steel Vane-Mesh Pack.

Horizontal and Vertical vessel orientations are available. Horizontal filter separators provide a lower sump to collect liquid dropout. Vertical filter separators use the bottom portion of the vessel to collect liquids. If no solid particles are present in the gas stream, the replacement of the elements is not required for extended periods of time.

Common Applications:

Power generation – fuel gas receiving stations.
Gas processing facilities.
Pressure reduction stations
Gas compressor stations
Various other applications where liquid and solid removal down to 1 micron is required.

Features Summery:

Separates solid particles, water, vapors, oil and other impurities from gas streams.
99.98% removal efficiency of 1 micron liquid droplets and solid particles.
Flow Turndown = 10:1.
AS 1210 or ASME VIII Div.1&2 (U-Stamp) design and fabrication.
Elements are easily replaceable with access through quick open closures for minimum down time.
Efficient and economical for a wide range of applications.
All filters and separators are custom designed to suit the project´s process conditions and site restrictions.
Pressure vessel registration with local authorities to comply with AS3920 & AS4343 (Australia).
Liquid level and differential pressure transmitters.
Complete Modular skid assemblies with valves, piping, instrumentation and structural skids.

Principles of Operation

Filter Separators are used to eliminate fine solid and liquid particles (down to 1 micron). This arrangement is used where application demands for high efficiency. Filter separators are also used to remove oil traces if any from the Gas flow.

This type of system utilised Filter Coalescer elements constructed from steel or stainless steel and polyester or polypropylene media combinations used to remove liquids and solids from a gas stream while maintaining very high performance efficiency. Stainless steel Vane and/or Mesh packs are also utilised to provide a secondary stage of liquid particles knock out.

The Filter separator system provides 99.98% removal of 1 micron solid and liquid particles from the gas stream. The elements are easily replaceable through a manway (Access) fitted to the top of the vessel.

Operation:

In filter separators solid particles are removed in 1st stage & liquid particles are removed in 1st and 2nd stages. Primarily larger solid and liquid particles are removed by gravity, since the velocity of incoming gas decreases as it enters the top chamber of the vessel.

In the 1st stage of filtration (Filter coalescer elements), smaller size solid particles and some liquid particles are removed using the filter coalescer elements.

Then the gas enters the vane/mesh pack arrangement i.e. 2nd stage of filtration where the remaining liquid particles are removed to a high efficiency.

The contaminants are collected in the top and bottom chambers where they can be drained periodically. Filter separators are capable of maintaining high performance down to 10:1 flow turndown ratio.

Knockout Stage

As natural gas enters the Filter Separator, it impinges on element support posts, also known as risers. A correct length of the risers is crucial in preventing direct gas impingement on the elements. Gas impingement on the risers is used to disengage any heavier contaminant from the gas stream via impaction, deﬂection and gravity. In order to maximize deﬂection and make the most of gravity separation, Tresca Filter Separators utilize a special optimized riser layout.

Element Stage

In the standard oﬀering the element stage of the Filter Separator is ﬁtted with Tresca depth style cartridges made from varying bonded media. The direction of ﬂow is outside to in for highest solids removal capacity. The elements also serve the function of coalescing small liquid droplets. The pre-coalesced droplets are now ready to be removed from the gas stream in the ﬁnal separator stage. Element change-out is performed based on a pre-determined interval or diﬀerential pressure.

Separator Stage

Depending on the nature of contaminant, the separator stage can be ﬁtted with one of three available separation devices:

A wire mesh mist eliminator
A vane pack or mesh-vane assembly
A centrifugal device

Wire Mesh Mist Eliminator

For maximum performance, two Tresca knitted mesh pads of varying density and thickness are ﬁtted into the second compartment. Typical materials are various grades of stainless steel. Nonstandard materials are also available for special applications. Low pressure drop and cost eﬀectiveness are two of the beneﬁts of using wire mesh. Wire mesh is not recommended for sticky fouling contaminant or for highly corrosive service.

Vane Mist Eliminator

Tresca vane packs are custom engineered to meet process requirements. A multitude of specially shaped plates creates a tortuous path for the gas to pass through. Typical materials are various grades of stainless steel with a carbon steel enclosure. Low pressure drop, compact design and longevity are some of the beneﬁts of using a vane pack in the ﬁnal stage of a Filter Separator. The use of a vane pack should be limited where sticky and fouling contaminant is expected.

Horizontal Filter Separator

A horizontal Filter Separator is ﬁtted with two separate liquid collection chambers. Depending on client preference and liquid loading, each unit can be built with a single horizontal sump or two vertical liquid collection boots. A horizontal sump is separated with a baﬄe plate into two independent chambers. Each liquid boot or horizontal chamber is sized proportionally to the upper barrel as well as expected liquid loading. Two stages of controls (manual or automated) are required for liquid monitoring and drainage.

Vertical Filter Separator

A vertical Filter Separator is designed with a top to bottom ﬂow conﬁguration and is most commonly designed with a vane pack or mesh-vane separator stage. This design also necessitates two liquid collection chambers. Any liquid knocked out in the ﬁrst stage, or upper chamber, is collected and drained oﬀ to a common drain header. The second stage, or lower chamber, retains liquids that have been removed from gas stream by the vane pack.

Design Considerations

A number of other crucial design aspects include element ﬂow capacity, nozzle velocities, bulk and annular velocities, element spacing, nozzle positioning, gas contact area in the separator stage, pressure drop and ﬂux rates. When you purchase a Tresca Filter Separator you can rest easy knowing that all requirements of process design have been considered to ensure maximum performance.