Home Industry solutions Oil and gas industry Filters for gas turbine plants
Obninsk Filters Group specializes in the production of filter elements from the most chemically and thermally resistant materials – fluoroplastic (PTFE brand F-4, GOST 10007-80) and ultrahigh-molecular polyethylene (UHMWPE, TU 2211-001-98386801). In addition, all-metal filters are manufactured on the basis of stainless steel nets with laser-welded seams.
The main spectrum of tasks that we solve at enterprises of various industries is filtering chemically active and aggressive liquid and gaseous media .
Only in the last two years, Obninsk Filters Group began to work with enterprises of the oil and gas industry and at the moment the company's specialists have gained practical experience in solving some problems.
We would like to devote this article to the task of cleaning up media on a gas turbine unit.
- Gas filtration in the gas treatment unit for gas turbine stations at CHP plants.
- Condensate filtration
- Filtration of acid and alkaline solutions in reverse osmosis membrane washing systems.
1. Gas filtration in the gas treatment unit for gas turbine stations at CHP plants
In 2010, a project was implemented to install filters for cleaning gas at a level of 5 microns at two CHP plants. ECOSTEEL stainless steel filters with laser-welded seams are installed (Photo 1). On one unit at a flow rate of 84 000 m3/hour were installed in parallel 3 housings for 32 elements with a height of 500 mm each to ensure continuous operation of the system. System pressure – 1.2 MPa. Technical characteristics of ECOSTIL elements are listed in Table 1.
Table 1. Design and technical characteristics of elements ECOSTEEL (EFP-222)
|
Technical mark |
EFP-222 |
|---|---|
|
Characteristics of the filter material |
The 12X18H10T stainless steel filter mesh is made of twill weave with 5, 10, 20, 40 micron filter webs or plain weave with 70, 100, 150, 200, 300, 500, 1000 micron filter weights |
|
Filter Pack Geometry |
Non-corrugated filter pack – in the form of a sleeve on a frame from a perforated stainless steel sheet with internal stiffeners |
|
Welding Method |
Laser welding seams |
|
Filter cartridge geometry |
Outer diameter – 65 mm or 150 mm, height – unlimited As agreed, it is possible to manufacture filter elements according to Customer’s drawings. |
|
Operating Temperature Range, &C; |
-70 ÷ + 300 (in air) -70 ÷ + 800 (inert gas atmosphere) |
|
Maximum direct pressure drop, MPa |
2.0 MPa at + 40 º С 0.6 MPa at + 150º С |
|
Maximum reverse pressure drop, MPa |
0.2 MPa |
In this case, the filter elements were installed in existing enclosures, taking into account the required sizes. Obninsk Filters Group of Companies produces filter elements from stainless mesh with laser welding of almost any configuration. Due to the possibility of repeated regeneration of the mesh filter elements, the life of the filtration systems can be increased many times.
Also, in addition to elements based on stainless mesh or instead of them, deep-type filter elements of the brand are used. ECOPLAST-FEP-F from PTFE brand F-4c with a filtration rating of 5 or 10 microns (Photo 2). In addition to filtering mechanical impurities, PTFE filter elements provide purification from aerosol impurities. Due to the fact that PTFE is a hydrophobic material, the separation of moisture and oil vapors occurs on the surface of the filter element with the subsequent formation of droplets and draining them down under the action of gravity.
The working temperature of the filter elements ECOPLAST-FEP-F up to 150°C. Fluoroplast filter elements can be regenerated by reverse flow of steam-water mixture, live steam in the line, as well as other methods of cleaning and regeneration.
Currently, ECOPLAST-FEP-F filters are produced in four sizes. It is possible to manufacture filter elements according to Customer’s drawings.
2. Condensate cleaning to remove iron (III) hydroxide
Filter elements ECOPLAST-FEP-F of PTFE brand F-4 also proved to be good at filtering condensate on BOW. The globular fiber structure of fluoroplastic-4 sintered at a certain temperature allows the most efficient removal of iron (III) hydroxide molecules. In this case, it is possible to carry out repeated washing of elements in the direction opposite to the direction of filtration with both purified water and solutions of any acids. When this occurs, the dissolution of colloidal iron and the restoration of the service life of the filters. The use of cartridge filters significantly reduces operating costs, is more preferable from the point of view of ecology and industrial safety compared with the use of bulk filters with sulfonated carbon and activated carbon. (Zhadan A.V., “Cleaning of condensate at energy facilities.” Materials of the V International Water-Chemical Forum, M., April 3-6, 2012).
3. Filtration of acid or alkaline solution in reverse osmosis membrane washing systems
For filtering acid and alkaline solutions, a necessary parameter is the high chemical resistance of the material. The specialists of the Obninsk Filters Group have developed a technology for producing a filter film from ultrahigh molecular weight polyethylene (UHMWPE). The material has high thermal resistance (up to 100 &C) and chemical resistance comparable to the characteristics of polytetrafluoroethylene, which allows the use of elements in a wide range of pH (1-14). The inertness and neutrality of the material, the absence of drainage non-woven materials in the construction of filter elements, the high mechanical strength of the filter material makes it possible to carry out repeated regenerations and washing, including in the direction opposite to the direction of filtration. The elements of ECOPLEN-PE on the basis of corrugated UHMWPE films possess optimal performance properties for solving this problem (Photo 3). Depending on the required performance, ECOPLEN-PE filter elements with a filtration rating of 5 μm are installed in multi-cartridge filter housings for 18, 24 or 36 seats, which ensures a capacity of up to 120-140 m3 / hour per filtrate. The lifetime of one set – from 1 to 2 years, depending on the degree of contamination of the solutions and the frequency of washing the reverse osmosis membranes.
In conclusion, it should be noted once again that these tasks are only part of the solutions for cleaning liquids and gases that we have implemented using chemically and thermally resistant materials based on PTFE of the F-4 brand and UHMWPE and stainless steel. In addition, fluoroplast-4-based filters are most actively used for cleaning turbine and transformer oils, associated gas purification projects and installation of breathing filters on the tank are implemented storage of drinking water for rotation camps.
Astakhov E.Yu., Ph.D., Deputy Director for Research,
Kotova A.Yu., Ph.D., Head of Industrial Filtration Department,
Pankratov A.A, deputy head of Industrial Filtration,
Gorobets S.V., Leading Specialist, Industrial Filtration Department, RME Eco-Filter