Filter blocks are a well-established water and air distribution device internationally. Building on advanced technology at home and abroad, Zhongchang has developed the ZS-G type high-density polyethylene filter block, which combines the advantages of filter heads, filter plates, triangular channels and double-layer filter blocks - uniform water distribution with low head loss. It is widely used in the water and air distribution systems of denitrification deep-bed filters and of other new and retrofitted filters using air-water backwash or water-only backwash.
Our company is a drafting unit of the industry standard for Filter Blocks for Water Treatment, CJ/T 47-2016.
Structural Features
The secondary water distribution formed by the bottom side channels distributes both air and water evenly, improving the uniformity and stability of water and air distribution.
The surface water and air distribution orifices are set within recesses, preventing blockage by flat gravel in the support layer and promoting a uniform, stable support layer; the open area ratio stays accurate and does not deviate from the design data.
Spigot-and-socket connection with two O-ring seals provides reliable watertight sealing and ensures there is no leakage.
Flexible configuration: orifice diameters can be selected to suit the design, meeting the open area ratio requirements of all types of filter.
Produced in a single injection moulding operation, maintenance-free and corrosion resistant, with a service life of up to 50 years.
Lightweight, easy to assemble and to cut to size, and quick to install, reducing installation cost.
Technical Specifications
Dimensions
Overall dimensions (mm): 950 x 270 x 300
Upper-layer open area ratio: 0.6%-1.6% (made to design requirements).
Advantages of the Filter Block
A wider air velocity range, currently 5-25 L/(s·m²).
Uniform, continuous air flow to every orifice, giving more stable air flow under all operating conditions.
Water distribution non-uniformity reduced to below 5% overall, with better media cleaning. The closely spaced, non-clogging orifices of the filter block distribute backwash air and water evenly, which both safeguards trouble-free operation and achieves better cleaning. Some filter blocks have widely spaced orifices that readily create dead zones, so the air cannot reach the media and cleaning is ineffective; the closely packed orifice design of the G-type filter block prevents dead zones so that all the media is fully cleaned by the air.
High-intensity backwash irrespective of media configuration: the uniform air distribution of the G-type filter block allows any media configuration to benefit from high-intensity combined air-water backwash.
Lower installation and operating costs. Lower installation tolerance requirements simplify installation, reducing the civil works cost of the filter. Filtration performance improves, giving cleaner effluent and longer filter runs, which in turn lowers the operating cost of water treatment and saves on both installation and operating costs.
