*Notes on Effective Filtration of Gel Type Particles*
　 　
　

To effectively remove gel-like particles, the following factors should be considered for filter specifications and filtration methods.


1.As much as possible, pressure drop(filter resistance) must be low during filtration.
2 Fluid flowrate against filtration media(fluid velocity) must be restrained low.
3 A high grade filtration media must be used.
4 Filter media with thin fibers must be used.
5 Filter media with high adsorption capacity must be used.
　 In gel type particle filtration, there are two types of filter commonly used, the fibrous media Pleated type filter and the Depth type filter.
However, for process lines in need of high grade filtration, a combination of both depth and pleated type of filter is highly recommended.

A) Depth-type Filter

A depth type filter is a multi-layered filter that integrates a particle filtration by mechanical sieving(particle entrapment by smaller sized pores) and adsorption.
Highly adsorptive fibrous media are generally used and has a deeper filtration area compared to a pleated type filter. It is very effective on low fluid flowrate applications although pressure drop is generally high due to the limited surface area.
Also, upon saturation of binding sites, smaller particles tend to pass through the filter unaffected making particle "breakthrough" possible.
　

[Structure]

[Cross-section]

 

B) Pleated-type Filter
Extra-fine fibrous media with high adsorption capacities are generally used.
Increased filtration surface area is achieved by pleating, thus lowering filter resistance and increasing gel type particle removal.

[Structure]

[Cross-section]

C) Combined fibrous type filter media and membrane type filter

The fibrous filter media serves as a pre-filter media for trapping gel-type particles, while the membrane is the main filtration media for minute particle filtration. 
We propose this type of filter for precise filtration applications for fluids having dissolved gel type particles.

[Structure]

[Cross-section]

　　
Depending upon the structure of the gel type particle and filtration condition, if filter resistance is low(low flowrate), removal of gel type particles is possible even by using a coarse filter. 
On the other hand, it is possible for gel type particle "breakthrough" even from a smaller pore sized filter, if filter resistance becomes high. 
Relationship between pore diameter and breakthrough point is shown in the graph below: 
　

　

Yamashin Filter Manufacturing Corporation
Process Filter Group
Phone:045-324-7768     FAX:045-311-2097
Kenji Ando

*Notes on Effective Filtration of Gel Type Particles*