The word “filter” means a Device that removes something from whatever passes through it; An electrical device that alters the frequency spectrum of signals passing through it. Filters are not strange to people. It may refer to Chemistry, engineering, materials, optics, photography, Signal processing, computing, philosophy and so on.
Especiially in household usage, e.g. water filter, pepole know it very well. Water can be cleaned using a variety of different types of water filters, both for drinking and other purposes. Filtration forms a key stage in many waste water and drinking water treatment systems. In the case of drinking water, filtration tends to be carried out by the supplier prior to the water's entry into the distribution system. Additional filtration may be carried out by consumers at their premises using any of several types of domestic water filter.Domestic water filters are primarily used to remove chemicals and metals such as chlorine and lead. Water filters can be used for preventative health reasons in the case of harmful substances, or for reasons of aesthetics, to improve the taste, colour or odour of drinking water. Domestic water filters can be attached directly to a tap, attached to the domestic water supply before the tap, or filters can be used at the point of use or in a portable unit.
Magnetic filters maybe are not familiar to pepole. But it is an important kind of magnetic applicationt. Magnetic filter isdesigned to get rid off iron/steel substances in liquor then be widely used in industry like medical treatment, hygiene, textile, machinery , foodstuff, feedstuff, chemical industry ,etc. Magnetic filters are constructed from several magnetic filter bars,stainless steel and have a satin finish, then fixed onto a framework. The magnetic filter bar is made of permanent magnets and stainless tubes with special magnetic circuit. When liquor containing iron steel substances passes through the framework, the iron steel substances will attach themselves onto the wall of the filter bars Magnetic cartridges. So as to guarantee equipments in a good codition,facilities be safe and sound and products keep safe for consumption. All kinds of magnetic filter frameworks are build. The normal diameter of magnetic filter bar is available from 20mm to 40mm.And its magnetic flux can reach 12000GS. But size and length of the magnetic filter bar, and shape of the framework can be produced according to customers' requirement by many magnetic filter companies.
References
http://www.magnets-china.com/magnet_lifter.htm
http://xionghai.en.alibaba.com/product/50046868/50213492/Magnetic_Filter.html
http://www.nbyjyc.com/
http://en.wikipedia.org/wiki/Magnet#Types_of_permanent_magnets