working principle of loosen disc filter( take azud product as example, shen ones is the same with it): its internal support is specially designed in order to press disc compactly by spring and hydraulic pressure.both sides of thin plastic lamination with special color are carved with grooves with certain micron size, when a cluster of plastic disc with the same pattern are pressed compactly, grooves between laminated disc are intersected, thus a seried of unique filtering channels come into being( for grooves are not radial, so passing ability of channel are changing,take for instance, see upperright chart of following chart),all suspended manner which has diameter are larger than the minimum part of the channel are hold, most dirty are intercepted between disc and casing,a little are catched after entering channel; when backflushing, power on disc are removed, disc are loosen under the water power, clean water enter inside of disc through channel of internal support, and is sprayed at a tangent, thus disc is rotated by this power, dirty on disc channel can be removed completely.

the first product of full-auto disc filter which entered the chinese market is the one of amiad. because this corporation has its own mass-flow screen filter, so it did not make its disc ones widely aailable in industrial water treatment feilds. arkal ones and other israel products were earily put into agriculture use.for instance, famous israel irrigation corporation-netfim introduced arkal filter system in agriculture much earliy. but it is beijing jieming corporation that started the the large-scale application of disc filter in industrial water treatment feilds.in 1996, as agent in main land china of arkal, beijing jieming corporation introduced arkal disc filter into industrial water treatment feilds and did a lot of promotion work.yagao disc filter, named by her,has once been synonymous with israel disc filter.but for some reasons, agency relation between jieming and arkal has been terminated. beijing jieming corporation developed its own disc filter which is much similiar with that of arkal, and sells them named as yagao in domestic. elgo disc filter features high filtering precision and is much different from that of arkal. it can provide extremely high filtering precision(it boasts 5um).