Friday, 3 February 2017

Which mesh type is perfect for deep filtration?


Woven wire mesh has major applications as filters in diverse filtration applications for example flow control, aeration, chromatography, breathers, vents, instrument filters, sensor protectors, fuel cell parts, dampers and for separation of liquids and gases.

Metal meshes are used in applications for filtering, damping and metering in fluid flow systems. Few applications of the mesh filters are discussed here:

a.       Metal mesh filters remove solid particles from liquid streams like oil, gasoline polymer melts and aqueous suspensions and from air streams or other gases. Metal mesh has god strength to prevent breakdown during entry in the filtered stream, adequate ductility to prevent fracture because of mechanical or thermal shocks and offer efficient and extreme filtering of materials.

Essential characteristics needed in filter materials are:
a.       Supreme mechanical strength
b.      Retention of solid particles of a specified size
c.       Fluid permeability to permit a specific volume of fluid of a selected viscosity through unit area and thickness of a filter in the specific pressure gradient
d.      Supreme resistance to environmental corrosion

Standard pore sizes are 0.2 – 100 microns. The commonly used metallic filter materials are stainless steel and high performance materials. For filtration of aggressive fluids, filter mesh constructed from Monel, Inconel, Titanium and other metal can be used.

Sintered Hastelloy wire mesh in the form of sheet or roll, have excellent performance properties. These properties include flow (gas-liquid), filtration efficiency, surface properties, strength and adequate corrosion resistance. By meeting these criteria of a specific application, metal filter mesh media becomes a practical material that a design engineer for various applications.

Filtration is the crucial application for any mesh material. Sintered wire mesh is used for filtration of both gases and liquids. The high strength and corrosion resistance properties of material make this media perfect for vigorous application media and with these advantages as long life and easy cleaning. Common applications are:
  • Solvent Filters for chromatography
  • Filters for molten plastic
  • Catalyst recovery in petrochemical systems
  • Food and beverage plants
  • Gas filters for chemical processing
  • Semiconductor manufacturing applications
  •  Sensor covers for example smoke stacks and exhaust pipes

The woven wire mesh is also used in flow control systems, breathers and pressure equalizers that implement tight and controllable flow features to monitor the flow of gases or liquids in the process. Few examples of such systems are-
  • ·         Mounted flow restrictors rather microvales and orifice equipments for finding gas leaks in mines
  • ·         Analytical systems
  • ·         Vent plugs that permit internal pressure equalization with external atmosphere in space crafts
  • ·         Trucks and train brake systems
  • ·         Instrument cabinets utilized in vigorous media
  • ·         Vacuum delay valves in automotive carbuerators
  • ·         Pump priming vents for pharmaceutical micropumps



Sintered wire mesh elements are used for deep filtration by careful distribution of hole size and length of flow that are based on particle size, shape and component dimension. The depth-filter offers higher particle retaining capacity as compare to screen filter even also offers higher pressure drop as compare to screen of equivalent porosity rating. The design of filter is crucial as pressure drop is determined by the porous structure, working place and thickness of system. 

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