Paramount Limited
 
 
 

 
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Paramount offers Dissolved air flotation (DAF) units to treat emulsified oil, free oil having finer oil globule sizes (sizes less than 45microns which normally cannot be removed by gravity separators in an economical manner) and suspended particles in the effluent.

DAF separation principle is based on the fact that air soluble in the liquid is in direct proportion to the pressure applied. A part of the treated effluent is recycled to the saturation vessel by means of high pressure recycle pump. Two methodologies are used for air injection – air injection in the recycle pumps and the most widely used saturation/ pressurization vessel to ensure saturation of the liquid with air.

The saturated liquid is de-pressurized into the flotation tank through a valve located as the discharge line of recycle pump near DAF Unit. When the pressure is released the air dissolved under pressure comes out of the solution in the form of minute bubbles. These minute bubbles get attached to the flocculated effluent and thus forming surface floating scum like solids with a specific gravity less than the effluent. A skimmer is normally employed to de-skim the scum from the water surface.

Paramount offers DAF units in three models suiting the various needs of the client.

1 Circular DAF unit with a skimmer cum scrapper arrangement
2 Rectangular DAF unit with a skimmer cum scrapper arrangement
3 Lamella types DAF unit with skimmer and sludge outlet

 

Circular DAF

Paramount designs and manufacturers the circular DAF systems based on technology acquired from M/s. Esmil Process Systems Limited, UK.

Effluent dosed with a coagulant and/ or flocculant solution from flocculation tank is fed into coagulation tube (feed well) situated at the center of DAF unit.

Coagulation tube is a vertical cylinder suspended in the center of the tank where the flocculated effluent enters tangentially to ensure intimate mixing of the flocculated solids with the micro bubbles which are generated due to de-pressurization of recycled effluent (which is also fed tangentially).

The floating scum layer is continuously skimmed from the top water surface by a motorized skimmer moving perpendicular to the circumference of the DAF unit into the scum box for further disposal.

A bottom scrapper attached to the shaft of the motorized skimmer pushes the bottom sludge into the central sludge cone for periodic de-sludging operation.

The circular DAF basin is designed in steel and RCC structures depending on the size. Larger units (normally above 4m in diameter) are normally in RCC basins.

Our Standard Range / Capacity / Size - 30 m3/hr to 1000 m3/hr flow.

Rectangular DAF

A rectangular construction is predominantly selected in plots having a space constraint and are normally in RCC constructions and is an adaptation of the Circular DAF.

The operation of the unit is similar to the circular DAF unit. The main variation being that the skimmer cum scrapper mechanism has a reciprocating motion along the length of the unit with the scum and sludge accumulated towards the inlet of the DAF unit. A baffle constructed at the inlet positively isolates the skimmed scum from being dispersed with the influent.

A screw augur mechanism is installed at the bottom of the DAF unit in the longitudinal sludge pocket. The screw augur helps in periodic de-sludging operations.

Our Standard Range / Capacity / Size - 30 m3/hr to 1000 m3/hr flow.

Lamella types DAF unit

Paramount offered lamella type DAF units are called Tilted plate flotator (TPF). The TPF offered by Paramount Limited is the technology absorbed from M/s PWT, Netherland.

Tilted Plate Flotator units are widely used for removal of emulsified oil, suspended solids etc., present in wastewater.

Effluent should be properly flocculated before it is fed to Tilted Plate Flotator. For this purpose more often a Pipe Flocculator is included prior to the TPF unit. Alum and polyelectrolyte solution are dosed for floc formation before an effluent feed to the TPF unit.

The flocculated effluent flow receives air-saturated water (recirculating treated water) originating from the outlet side of the Tilted Plate Flotator.

The recycle stream has air dissolved in it. The pressure is then released, resulting in the generation of minute diameter (micro) bubbles. These micro-sized air bubbles attach themselves to the flocs formed in the flocculates so that rising conglomerates build up.

The recirculation system consists of suction & discharge piping for recirculation pump, recirculation pump and deaerator (saturation vessel).

The conglomerates are subsequently separated in the Tilted Plate Flotator system. Here, flocs are separated in the corrugated plate pack which is installed at an inclination to create a maximum surface area for separation in a minimum volume. Flow through these plate packs is maintained as laminar thus creating ideal separation condition. The separated conglomerates collect in the corrugated plate crests and subsequently flow upwards in the pack in counter-current, eventually forming a compact floating layer on the liquid surface.

The floating layer of the Tilted Plate Flotator units is continuously compacted and skimmed by a patented scrapper. The treated water leaves the plate pack at the bottom end, rises and is then discharged over an adjustable weir. Accumulated solids, having settled are periodically removed by a hand operated butterfly valve.

A screw augur mechanism is installed at the bottom of the larger TPF units in the longitudinal sludge pocket. The screw augur helps in periodic de-sludging operations.

TPFs can be supplied in modules of up to six plate pack per basin in steel structural basin. Larger units can also be adapted in RCC structures.

Our Standard Range / Capacity / Size - 5 m3/hr to 100 m3/hr flow.

 
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