Thickening devices are used commonly by wastewater treatment plants for increasing the solids concentrated at the very end of a particular process step inside the process of activated sludge. Thickening of the sludge can increase the content of the solids and decrease the volume of free water which actually minimizes the unit load processes downstream like dewatering and digestion. The most common type of used processes of thickening comprises floatation of dissolved air, thickening of gravity and thickening of the rotary drum. In modern days, centrifugal thickening is also becoming more common. The thickening type selected is mainly determined by the wastewater plant’s size, the downstream process, and the physical constraints. We can offer gravity thickening, centrifugal thickening, dissolved air floatation thickening along with rotary drum which depends upon the availability of space and the applications of the process.
The process of thickening is applied to obtain a high ratio of solid materials by taking out the excess amount of water that is present in the sludge. Even the lowest rate of increase can obtain a significant rate of decrease of the total sludge volume. It can offer a very cost-effective solution as the reason that smaller types of treatment plants can be required. Thickeners are used as the common equipment to increase the solid waste’s density coming from the treatment of wastewater and water and then transmitting it towards the dewatering plant. The result of the high density of the sludge gets affected in the sludge flow getting reduction and the size of the subsequent dewatering sludge steps. The concentration of solid gets increased by the thickening of gravity by allowing the particles for getting settled at the vessel’s base of that can produce a thickened stream of solid the base of the vessel and a supernatant stream along the surface. Settling or sedimentation is the simplest way of thickening. Any gravity sludge thickener comes with the same features of design as a primary sedimentation tank which is used for the treatment of wastewater and most often comes with cylindrical geometry. One of the common variants of the design of the gravity thickener lies with the picket fence thickener. This type of technology comes with a stirrer which has a series of various closely-spaced vertical arms and this is very much having a much similar appearance towards a picket fence.
For the two types of designs, the sludge can get inside the center of a cylindrical tank and flow out towards the periphery. When the flows of water are towards outside from the centre, the solids that are suspended sink towards the base of the cylindrical vessel, where they get scraped into the outlet that has a cone-shape by means of a rotating scraper and gets removed as the stream of sludge product gets thickened. Then the supernatant diluted stream which reaches the wall of the tanks gets flows over a weir at the surface and is mostly gets directed back inside the inlet of the wastewater treatment process.
Very similar to circular scrapers, we supply two types of circular thickeners like the follows –
• Comes with a reliable and robust design
• Has completely trouble-free operation
• Has a highly efficient mechanism
• Provides high concentration of sludge
• Can be found for basins in medium and small sizes
• Consumes low energy
• Comes with adjustable pickets and blades