Thickening

THICKENING

Traditionally used to reduce the amount of liquid in the digestion phase of the plant, thickening can be accomplished either through gravity style thickening tanks or mechanical means. Thickening tanks typically are larger and require more footprint, however they do not require buildings and yield polymer savings to achieve their ends. Gravity thickeners are more functional on primary solids than secondary. Mechanical thickening is usually done with either a rotary drum, gravity belt, DAF or centrifuge but a good three belt press can dual function as a thickening device by utilizing the gravity deck portion of the press and an earlier take off point. This can offer substantial saving if a facility can combine thickening and dewatering in one unit.

Mechanical Thickening

BDP Industries, Inc.

Gravity Belt Thickener

Tenco Hydro Clari-Float provides high performance by the use of proprietary design features to maximize DAF performance. These include a proprietary inlet chamber and recycle pressurization system.
The inlet chamber dissipates energy and turbulence from the mixing of feed and depressurizing flows. It is then transformed to an evenly distributed laminar flow as it enters the DAF cell. Additionally, any excess (undissolved) air is captured and vented outside of the DAF cell, thus preventing air turbulence and disruption of the floated sludge at the surface. This results in optimum use of the DAF cell flotation area.

Optimum DAF performance also requires consideration of influent characteristics to determine the applicable design parameters such as hydraulic and solids loading rates and air to solids ratio. Air is delivered by the use of pressurized recycle flow. Tenco's proprietary recirculation system has been proven, by rigorous full scale testing, to dissolve air in water in excess of 87% saturation efficiency. This high efficiency minimizes the energy used to deliver the air necessary for solids flotation.

Clari-Float DAF systems have been supplied in circular, rectangular and rectangular high rate configurations. Materials of construction have been carbon steel, stainless steel or concrete.

Gravity Thickening

Amwell

Gravity thickeners is essentially a type of clarifier and relies on the density of solids to settle and thicken the sludge. They consist of a circular tank with a sludge collection system at the bottom. They are typically center fed with a discharge weir and have a collection system that sweeps the solids to a center well for removal in the center sludge hopper and pipe.

Kusters Water

Kusters Water Gravity Sludge Thickeneres
Gravity thickeners are designed for most applications involving sludge thickening. Solids are thickened by gravity, then collected at the bottom of the basin and raked to a collection sump for removal. The clarified effluent exits over the weir plates and out of the basin. To find out more about Kusters Water Gravity Sludge Thickeneres click HERE