Gravity Tables are a very cost effective means of thickening sludge. The simplicity of the machinery makes it easy to maintain and it's low power consumption makes it inexpensive to operate. Compositech's GT series of Gravity tables, also known as gravity belt thickeners, are typically found in municipal wastewater plants, but may also be used in industrial wastewater facilities. Compositech gravity tables are designed to concentrate sludge, by means of gravity drainage of water through a permeable synthetic belt. Our design provides for extended drainage of dilute, high volatile and unstable sludges. Our gravity tables are designed for continuous 24-hour per day, 365 day per year operation with minimal maintenance.
Compositech's gravity table employs the forces of gravity for filtration in order to allow liquid to drain from the sludge through a single woven cloth filter belt. Initially, the liquid sludge is conditioned by adding polymers to obtain a separation between the liquid phase and the solid phase. Once flocculated, the sludge passes through the feeding box onto the synthetic belt supported by a high-density polyethylene (HDPE) grid which is supported by a stainless steel framework. The free water is separated by a combination of gravity and atmospheric pressure. In addition to supporting the belt, the HDPE grids break the surface tension on the underside of the filter media and encourage the free standing water to drain through and be collected in a drain pan below, while the filtered solids remain on top of the filter belt. A series of special plows continuously turn, push, compress, and distribute the sludge across the width of the belt, allowing for optimal drainage of liquids. The thickened sludge, in a semi-fluid state, is removed from the belts by a doctor blade mounted at the discharge end of the thickener. At this point, the sludge can be easily pumped to the next stage of de-watering or disposal. Cleaning of the belt is accomplished by belt washing stations containing a pipe with nozzles where pressurized water is sprayed through the filtering surface. A pneumatic system provides for tensioning and the automatic centering of the belt.
To better accommodate specific customer needs, Compositech's gravity table is designed to accept an optional cover for the filtration area. Other modifications can be made to meet the requiremements of specific applications.
In addition to our own manufactured gravity tables, Compositech services and stocks replacement parts for gravity tables made by other manufacturers. We stock feed boxes, bearings, doctor blades, plows, belts, mixers, gaskets, rollers and many other spare parts.
We manufacture Compositech replacement parts for Andritz, Sernatech/Sernagiotto, Ashbrook, Parkson, Komline-Sanderson® and various other gravity table manufacturers. Our replacement parts meet or exceed the quality and material of OEM components.