Filtration Systems Types and Terms
Filtration System Types
- involves the use of a porous
cartridge filter, commonly made of polypropylene (PP) or ceramic, which
catches particles as liquids pass through it. Cartridge filtration
is an easy filtration method but not suitable for liquids with high
turbidity and fouling remains a common problem leading to filter replacement.
- , also called "centrifugal filters" or "cyclone
separators," use cyclones in which substances, such as immiscible
liquids, gases and solids, are separated during rapid rotation from
the contaminated fluid. The rotation of the cyclone is caused by the
entrance of the pressurized fluid from which the contaminants must
be removed.
- removes contaminants through the use of a chemical
medium, such as activated carbon, in the filter. Chemical filtration
remains common in the filtration of gases.
- is a filtering process that involves electrically
charged media that use an electric field to filter substances and remove
particles as small as .01 micrometers in size. As the substances pass
through the charged media, certain particles are attracted to the charged
media.
- is the process of passing fluid through a filter to remove contaminants.
- includes filters, strainers, and housings.
- may involve the removal
of particles from a liquid, known as "liquid-solid filtration," or the separation of
liquids from gases, known as "gas-liquid filtration."
- involves the use of a membrane as the filter
media to allow the passage of substances such as air and water, while
preventing
the passage of other substance particles. Membrane filters are small
and automated and used for applications that include purifying blood
during dialysis treatments, removing bacteria and odors and desalinating
water.
- is a type of membrane filtration used to remove extremely
small particles. The effectiveness of nanofiltration lies between
that of reverse osmosis and ultrafiltration.
- is necessary to remove particles and contamination
that may hinder the functioning of equipment. Oil filtration
remains common
in the automotive/trucking and agricultural industries, as well
as other industries that utilize equipment requiring the use of
motor, hydraulic and other types of oils.
- ,
excluding rotary drum pressure filters, are semi-continuous machines
whose collection of filtrate is dependent upon the
operating mode of the filter (e.g. constant flow rate, constant pressure
or both, with pressure rising and flow rate reducing). Pressure
filtration is
a batch process that is typically fed from and discharged to
a continuous
process and requires a surge tank located upstream from the
filter
and a batch collection of cake downstream.
- is a type of filtration method in which water is
pushed under pressure through a membrane, while contaminants
are prevented
from passing through the filter. Filtered contaminants include
sodium, phosphorus, aluminum, lead and fluoride.
- involves the purification of water for drinking
purposes. Wastewater is also filtered to remove excess
particles.
- is a biological filtration process involving the
exposure of the filter medium to air to facilitate nitrification.
Wet/dry filters are commonly used in aquariums.
- is a type of membrane filtration that removes particles
ranging from 0.002 to 0.1 micrometers in size. Filtered
substances include bacteria and viruses.
Filtration System Terms
- The outlet located at the bottom of a
cyclone.
- The use of rotational forces to separate liquids
and solids.
- The neutralization of the electrical charges on fine
particles in water using chemicals called coagulants. The coagulants
cause the particles to clump together, and the clumps are then skimmed
or drained off or filtered from the water.
- The capability of a device to capture and
retain particles.
- Removing the top layer of a fluid after the heavier
material, which can be either a solid or a denser liquid, has settled.
- The act of removing dissolved mineral salts
from water.
- A non-porous membrane.
- The treated substance that emerges from the filtration
system.
- Any liquid, gaseous or vapor substance.
- The amount or volume of a substance passing through a given
unit of a membrane or filter in a given amount of time.
- The clogging of membrane filters due to the buildup of
particles on the membrane and in the membrane pores.
- A membrane in which the properties remain
the same throughout the substance.
- The substance that enters the filtration system to be
filtered.
- A film structure, having a thickness greater than its
lateral measurements, through which substances flow as the chemical separation
of substance particles occurs.
- The process of passing a fluid through a membrane to
increase fluid concentration.
- The superficial hydrostatic pressure on a semi-permeable
membrane caused by osmosis.
- The stream of fluid that leaves the cyclone through
the vortex finder.
- The ability of a fluid substance to pass through
a material. Filters have varying degrees of permeability that allow substances
of different sizes to pass through them.
- A unit of water containing fewer than 500 parts
per million (ppm) that is suitable for drinking.
- Unit
of measurement indicating one part per every million parts of air, water,
etc.
- A liquid containing suspended solids.
- Filtration mechanism for the removal of coarse particles
from liquid substances. Strainers usually function as an initial filtration
method used prior to other filters that remove smaller particles.
- The outlet at the
top of the cyclone through which overflow exits.