|Type||Air Flotation Clarifier|
|Use||water, Oil and Grease|
Dissolved Air flotation units are the popular options to remove oil, grease and suspended solids from water. The suspended solids, flocs are removed by dissolving air under pressure and releasing air in the flotation tank back to normal atmospheric pressure.
A typical Air flotation tank has a float cell into which the influent is pumped, then a part of effluent from float cell is recycled back to pressure drum. Here the recycled water is saturated with air and then it is mixed with the influent water. The air mixed with the effluent rises to top as tiny bubbles. The dirt, suspended solids, oil and grease adhere to the air bubbles and rise to top of the surface. This forms a layer of flocs which is scrapped of the surface with scrapper mechanism.
This clarifiers are most popularly used for removal of algae from sea water, Oil and Grease separation, pulp separation.
|Treatment Capacity||500 m3/hr|
Lamella Clarifier is popularly known as tilted plate separator. They are designed to provide more settling area to the suspended particles in water. In Lamella Clarifier an appropriate number of inclined plates are arranged in a particular pattern to allow the influent distribution and self cleaning of the settled solids. The Lamella Clarifier can be constructed in counter current, cross current or co current system based on the application.
The suspended solids present in the water settle on the inclined plates and slip gradually in the sludge collecting hopper bottom. The hopper bottom is periodically drained to flush out the suspended solids.
|Automation Grade||Semi-Automatic, Manual|
|Operating Temperature||55 degree C|
Tube settler works on the same principle as that of Lamella clarifier. In tube settler instead of plates specially honey comb shaped tubes of different length are provided. These are procured as sheets and assembled in structures at site. These structures provide inclined surface area which helps in rapid settling of suspended particles.
Often tube settler are provided with upstream coagulation and flocculation units. The influent with thick flocs of suspended is fed in counter current direction to clear liquid over flowing. The settled solids are drawn off from the bottom of the tank by periodic draining.
|Treatment Capacity||1000 m3/hr|
|Driving Principle||Centre Driven|
|Tank Diameter||70 m|
|Bridge Width||1.5 m|
|Approximate Power Consumption (in kW)||20|
|Tank Diameter||5 m, 50 m|
High Rate Solid Contact Clarifier are the most popular clarifiers in field of water treatment. They are preferred more than any other clarifier because they can handle large flow rate and provide better effluent quality outlet than other clarifiers.
A typical high rate clarifier is circular in shape, the influent is fed to flash mixer to mix the coagulants. Then influent is transferred in center well where the water is distributed in all the directions. The center well also works as flocculation chamber too as it provided with slow speed mixer and flocculation dosing. Then the influent is distributed through the energy dissipating device in radial pattern.
The sludge is continuously driven into the hopper bottom by continuous rating scraper. The bottom of tank is slopped to form a cone shape that helps in funneling the sludge to hopper bottom from which the sludge can be drawn out periodically.