Stainless steel filter cartridges can be in pleated form or cylindrical form.

This article will introduce the properties of stainless steel filter and compare the pleated filter cartridge with the cylindrical filter cartridge.

What is the stainless steel filter cartridge

Stainless steel filter cartridge is the filter element made of stainless steel filter media and hardware, and which is in the shape of tube or cylinder working as cartridge.

Stainless steel material for filter, mostly used

Stainless steel material for filter, mostly used

 

What is the application scenario of stainless steel filter cartridges

Stainless steel filter cartridges are more suitable to high temperature and high pressure working conditions than most of the non-metallic filter cartridges.

And they are applicable for various cleaning methods which are often not acceptable for non-metallic filter, such as high pressure water washing, chemical bath, ultrasonic cleaning, heating and even incineration.

Therefore the stainless steel filter cartridges are the best choice for automatic filter with backwashing or backflushing.

Auto backflushing diagram showing the flow direction, from Hydac

Auto backflushing diagram showing the flow direction, from Hydac

What is the stainless steel filter cartridge designed to replace

Pleated mesh filter:

Stainless steel pleated mesh filter cartridges are the substitute of various synthetic fiber non-metallic filter cartridges, such as paper, cellulose, PET, PP, PTFE, fiber glass, etc.  The pleats are made by pleating/ corrugating.

Non-metallic pleated filter from Pall

Non-metallic pleated filter from Pall

Pleated metal mesh filter cartridge with Fin

Pleated metal mesh filter cartridge with Fin

Cylindrical mesh filter:

Stainless steel cylindrical mesh filter cartridges are often the alternative to filter bags.

Filter bags are often one-way filtration filter elements which can not change the flow direction and do not often support backwashing.

However, cylindrical mesh filter can obtain same filtration effect but with additional benefit of reverse flow capability and withstanding higher working pressure.

Filter bag from Pall

Filter bag from Pall

Cylindrical wire mesh filter cartridge with 226 adapter and perforated metal tube inner support

Cylindrical wire mesh filter cartridge with 226 adapter

How to calculate the filtration area of stainless steel pleated mesh filter cartridge and cylindrical mesh filter cartridge

Pleated mesh filter:

Filtration area= (pleats height)*2*(pleats quantity)*(effective cartridge length / the length of mesh area)

Take PF65-250 ( diameter 65mm and length 250mm ) as example:

Pleated mesh filter, filtration area=7.5mm*2*36*250mm=0.135m2

Pleats of pleated mesh fitler cartridges, one finger on top of the pleats for size comparison

Pleats of pleated mesh fitler cartridges (large capacity)

Cylindrical mesh filter:

Filtration area=pi()*(outer diameter of mesh area)* (effective cartridge length / the length of mesh area)

Take CF65-250 ( diameter 65mm and length 250mm ) as example:

Cylindrical mesh filter, filtration area=3.141593*65mm*250mm=0.051m2

Spot roll welding seam of cylindrical wire mesh filter cartridge, background are mesh filter baskets

Spot roll welding seam of cylindrical wire mesh filter cartridge

For same size filter cartridge, the pleated type has times of filtration area of the cylindrical type’s.

What is the filter media of stainless steel pleated mesh filter cartridge and cylindrical mesh filter cartridge

Stainless steel wire mesh/ wire cloth, stainless steel sintered metal fiber felt, and stainless steel sintered wire mesh ( multi-layer wire mesh diffusion bonded ), sintered porous metal powder are the three main type of filter media for filter cartridge. One single type or any combination of types can be used.

The wire mesh and sintered mesh have the surface filtration property. The solids/ impurities are stopped by the mesh and stay/ accumulated on the mesh surface. The solid can be easily removed or collected during the cleaning process.

Sintered metal fiber felt has 3D porous structure as the metal fiber laid layer by layer and diffusion bonded. The porous structure can capture the solids and have high dirty holding capacity. The filtration is in-depth filtration similar as non-woven media.

Filter media for stainless steel pleated and cylindrical filter cartridge

Filter media for stainless steel pleated and cylindrical filter cartridge

What is the advantage of stainless steel filter cartridge

Comparing to the non-metallic filter elements, the stainless steel filter cartridges have the advantages of:

  • Working for high temperature
  • Withstanding high pressure
  • Washable and reusable
  • Suitable for automatic backwashing / backflushing
  • Anti-static
  • Good heat transfer

The shortage / Cons of stainless steel filter cartridge

  1. Weight. Stainless steel has times of weight than non-metallic materials.
  2. Cost. Stainless steel filter is more expensive than most of the non-metallic counterparts.
  3. Corrosion resistance. Although 316L and higher grade stainless steel have good corrosion resistance, they can not compete with some non-metallic material like PTFE in certain severe corrosion conditions such as HCL hydrochloride acid
  4. Limited filter rating. The micron rating of stainless steel filter is limited to 0.5 micron minimum by now and not possible extended to 0.01 micron or smaller in near future. Therefore, stainless steel filter now is mainly used in filtration of micron and millimeter range.