Sand cylinder filtration principle:
Sand cylinder is generally placed in a certain scale of quartz sand, within a certain range of quartz sand size specifications are different, in the sand cylinder, quartz sand from top to bottom, from small to large in accordance with this arrangement, normal filtration, the water is from the upper layer of the sand into the lower layer out. When the water flows through the filter layer from the top, part of the solid suspended matter in the water into the tiny eye formed by the upper layer of filter media by the adsorption and mechanical retention effect is retained by the surface layer of the filter media, at the same time, these are retained between the suspended matter and overlap and bridging effect occurs, as if the surface of the filter layer to form a layer of thin film to continue filtration of suspended substances in the water, which is called the surface layer of the filter media film filtration. This filtration effect is not only the surface of the filter layer, and when the water enters the middle layer of the filter also has this retention effect, in order to distinguish from the surface layer of filtration, this effect is called penetration filtration effect.
In addition, because the sand particles are closely arranged with each other, the suspended particles in the water flow through the sand layer of those curved pores, there will be more opportunities and time with the surface of the filter media and mutual collision and contact, so the suspended particles in the water in the sand layer of the particles on the surface of the flocs and flocculent bonding and contact coagulation process occurs.
In summary, the filtration of the sand tank is through the membrane filtration, osmosis filtration and contact filtration process, so that the water is further purified.
The principle of buried circulation filtration:
The buried circulation filtration system is an intelligent circulation filtration system that integrates pumping room, filtration, dosing and disinfection, etc., which changes the traditional sand tank filtration method. It is suitable for the standards of public swimming pools in many countries such as China and Australia, and is a filtration system specially used for large public swimming pools and competition swimming pools with more than 500 cubic meters.
Wall-mounted and embedded principle is the same as in-ground type, only the installation method is different.