Filter  Introduction

 

Filtration commonly refers to the mechanical operation of separation of solid particles (contaminants) from the fluids by interposing a filter media through which the fluids pass but solid particles of targeted sizes do not.
The physical state of the fluid can either be gaseous or liquid, and in this field where we design filters of pressure vessel type, the fluids are pressurized.

 

Coalescers  Introduction

 

To Coalesce can literally mean uniting several tiny droplets of fluid into bigger droptlets, and in the end, separating 2 different coalesced fluids.
These 2 different coalesced mass fluids form 2 separate layers of each fluid through the difference in densities of the 2 different fluids.
There are basically 2 major Coalescers that can be mentioned ;

One is the Liquid-Liquid Coalescer, which, for example, removes Water from the
Diesel Oil (Kerosene), and the other is the Gas-Liquid Coalescer, which removes the liquid from the Gas phase.

 

Depth Media Filter  Introduction

 

Sand, Walnut Shell and Activated Carbon are the typical types of deepbed-media employed depending on the purpose of their installation.

 

Besides the most commonly used media mentioned above, garnet, ilmenite, alumina, magnetite, anthracite and quartz can be considered for the performance and/or as a media support.
As the media depth filter involves the ability to retain the particles that penetrate throughout the medium channels, rather than on its surface, it requires a certain depth (height) of the media bed.

 

In case the bed is not deep enough and/or the flux rate is high, the particles may pass through the media bed all the way to the downstream, or may dislodge the particles which were previously retained in the channel.

 

 

Single Media Depth Filter

In general, the single media filter, represented by “Sand Filter”, employs only one grade of sand as a filtering media. Once it is backwashed, due to the density difference of each sand medium, the bigger and heavier sand medium falls on the bottom, while the finer media remain on top of the media bed.

In this case, the filtration performance will be weighted on top 100mm of the media, resulting in more frequent backwash requirement.

 

 

Multi Media Depth Filter

Besides the support gravel layer, 2 or 3 different types of media can be used in conjuction with one another.

Light in weight but larger sized media such as walnut shell or anthracite on the top layer acts as a coarse filtration. Heavier media with smaller size (dense) such as sand or garnet forms a layer under the first top layer, and retains the smaller particles that passed through the top media bed.

This allows the entire bed to act as a filter allowing much longer filter run times between backwash and more efficient particulate removal.