In desalination pre-treatment applications using gravity filters, the underdrain is one of the most important components contributing to overall system performance and operation. The dual parallel lateral underdrain design of the TETRA® LP Block™ offers significant advantages for operators when used in pre-treatment of desalination plants. The TETRA LP Block robust plastic components are non corrosive, which is especially important in desalination plants, where salt in sea water causes corrosion. In addition, the nozzle-less design ensures there are no blockages that could potentially affect the performance of the filter.
The TETRA LP Block dual parallel lateral underdrains are popular with plant owners for their low headloss, lightweight construction and easy installation either as a retrofit or for new filter underdrain applications. The easy-to-assemble TETRA LP Block dual parallel lateral underdrain ensures equal distribution of backwash air/water, exceptional installation strength, integrity and maintenance-free life with no moving or wearing parts. In the TETRA LP Block dual parallel lateral underdrain, air and/or water is distributed evenly across the entire filter floor bottom during the backwash cycle to effectively remove and release solids from the filter. The use of concurrent air and water significantly reduces the volume of dirty backwash water produced and drastically lowers operating costs through the uniform backwash process. TETRA LP Blocks feature the patented GroutGrip™ and Anchor-Rite designs. The GroutGrip design increases resistance to uplift from the filter floor and offers 2 times the pullout strength of a conventional underdrain filter block. While the Anchor-Rite design securely fastens the block down to the floor. Additionally, the wide, low-profile design requires that fewer blocks be installed to cover a filter floor. Therefore, fewer joints and less grout are needed.
The TETRA FlumeFlow™ is a new development for the LP Block filter floor system to negate the need for a separate air header, which significantly reduces the capital cost of rapid gravity filters.