The Neva-Clog is a unique welded, high strength screen free of internal plugging. It consists of two sheets of light gauge metal in which circular perforations are made in a predetermined hole diameter and spacing. The sheets are joined by spotwelding in a specific pattern, dependent on the medium's application. This welding pattern, besides assuring uniform joining of the sheets, controls the functional characteristics of the medium.
Although originally developed as an underdrain material, Neva-Clog has found wide use as the filter media on pressure and vacuum filter leaves. It is often used with round or rectangular leaves and flat or conical underdrains. It provides fast precoating, easy cake release and easy leaf cleaning due a smooth surface. Neva-Clog resists abrasion and abuse during cleaning or acid washing. As the chamber material, Neva-Clog becomes a general purpose filter leaf for many applications when used with WEDGE-FLOW or Por-O-Septa.
Neva-Clog is used as a support for granular activated carbon in processing columns for removal of colors, odors, and tastes. It's strength and performance characteristics have resulted in its installation in sugar, chemical, petrochemical and food refining plants. Because of its rigidity, compared with woven media, it requires minimum undersupport and no protective top screen. Neva-Clog's particle retentivity, in the range of 100 mesh, enables it to handle all corresponding granular carbon and bone char. It's strength and freedom from internal plugging insure long service life, making it especially valuable for towers in inaccessible locations or in hazardous service. Neva-Clog is also used for underdrains in catalyst towers, resin towers and ion exchange units.