S-Type HDPE Underdrain Blocks

Features

• The structural design of S-type HDPE underdrain blocks divides the internal structure into two layers of laterals in order to offer superior distribution of both backwash air and water in terms of the uniformity and stability.

• The distribution orifices for water and air distribution are located within recessed grooves, preventing clogging by flat gravels in the media retention layer. This promotes uniform and stable distribution of the supported media layer, ensuring accurate perforation rates that align with design specifications.

• Socket-and-spigot connection with double-layer "O" - ring seals provides excellent waterproofing, ensuring no leakage.

• Flexible configuration allows selection of diameters of distribution orifices based on design requirements, meeting the process requirements for perforated area rates of various types of filter beds.

• One-piece injection-molded construction requires no maintenance, is corrosion-resistant, and has a service life of up to 50 years.

• Lightweight, easy to assemble, can be cut to size, facilitates construction, and reduces installation costs.

Advantages Of Underdrain Blocks

• Wider range of airflow rate, 5–25 L/s·m²;

• Uniform and continuous air flow to all orifices, ensuring more stable air flow distribution under all operating conditions;

• Improved filter media cleaning performance: one of main characteristic of the S-type HDPE underdrain blocks is their small spacings between distribution orifices, allowing to prevent clogging by media, and enabling uniform distribution of backwash gas and water. This not only ensures trouble-free operation but also achieves efficient media cleaning results. Some underdrain blocks have larger pore spacing, which can create dead zones where gas cannot reach the filter media, resulting in inadequate cleaning. The closely spaced pore design of G-type underdrain blocks prevents the formation of dead zones, ensuring that all filter media are thoroughly cleaned by the gas;

• High-intensity backwashing without considering filter media configuration: The uniform gas distribution of S-type HDPE underdrain blocks allows various filter media configurations to benefit from high-intensity gas-water combined backwashing;

• Reduced installation and operational costs: Low requirement for installation accuracy simplifies the installation process. This reduces civil engineering costs for the filter bed, improves filtration performance, ensures cleaner effluent, and extends the filtration run time. It also lowers operational costs for water treatment, thereby saving on both installation and operational expenses.

Technical Parameter

• Positive bearing capacity ≥ 60KN/㎡

• Anyway, the bearing capacity is ≥ 50KN/㎡

• Mechanical strength: bearing 60KN/㎡ for three minutes without cracking

• Backwash intensity: air 15-20L/S·㎡ + water 4-8L/S·㎡, water alone flushing 12-18L/S·㎡

Illustration Diagram

Installation Method

Specification And Size

Specifications, dimensions, and characteristics of Type I underdrain blocks

Specifications, dimensions, and characteristics of Type II underdrain blocks