Krofta Engineering Limite...

Dissolved Air Flotation (DAF) is a physio-chemical process of solid and liquid separation. This technology was developed by Krofta. It is often used in the pre-treatment or primary stage of a waste water treatment plant to initiate suspended solids removal in the system. Krofta has also achieved success with using our DAF as a secondary clarifier to reduce properties such as colour and turbidity.

The system involves the Krofta DAF main tank, Krofta Air Dissolving Tube (ADT), chemical dosing system, recirculation pump and an air compressor. Our DAFs can be constructed in fully metallic structures with any type of coating to meet client requirements. Further, we recommend civil tanks with metallic internal parts for very high flow rates.

The application of Dissolved Air Flotation is to separate solids from liquid,

The Megacell is our rectangular DAF with lamella plates inside. It is designed to handle high solids loading and high flow rates and offers increased surface area due to the presence of the lamella plates. It has a chain and scrapper mechanism which pushes the top layer of scum to one end which is later removed with the help of a paddle wheel. The bottom conical shaped hoppers store the settled sludge which are removed periodically from the system with the help of timer activated purge valves.

The floated scum is pushed to one side with the chain and scrapper mechanism and the paddle as wheel removes the scum from the top. It is designed to have a retention time of 7-10 minutes. It can handle a range of flow rates as low as 10 m3/hr up to over 1000 m3/hr in a single unit.

Megacell started out as a revolutionary DAF to increase the efficiency of the recovered fiber in paper mills. After several successful installations it is now running in various industries, most popularly for sea water desalination applications.

The minicell is the operationally simplest circular DAF model. It was developed especially for effluent having difficult and fragile solids and oil. Another special technical offering of the minicell is the three different height options available depending on the application, flow rate and solids loading. It has a scoop-type system to remove the floated sludge. The minicell is the operationally simplest circular DAF model.

It was developed especially for effluent having difficult and fragile solids and oil. Another special technical offering of the minicell is the three different height options available depending on the application, flow rate and solids loading. It has a scoop-type system to remove the floated sludge.

The bottom sludge is directed to one side with the help of wiper blades and removed periodically with the help of timer-activated purge valves. A single unit can handle a flow rate as low as 16 m3/hr and go as high as 712 m3/hr.

The Sedicell is a mechanically simple, yet robust circular DAF. It can be constructed in a civil tank for longevity and high flow rates, with wetted parts manufactured in metal, or the entire DAF can be constructed in metal as well. It has a spiral scoop system to remove floated sludge.

Sedicell has a retention time of around 30 minutes due to its height, hence it is perfectly suited to handle very high solids. This also leads to a high sludge blanket formation with high sludge consistency, making the sludge easier to handle for further de-watering processes. Sedicell has been supplied successfully as a secondary clarifier as well for colour and TSS removal in pulp and paper applications. The largest single unit of Sedicell can handle up to 2000 m3/hr flow.

Wastewater sludge dewatering is a crucial process in wastewater treatment plants and various industrial sectors that generate sludge as a byproduct of their operations. Sludge is a semi-solid mixture of water, organic matter, and inorganic particles that remains after the wastewater treatment process. Dewatering involves removing a significant portion of the water content from the sludge, transforming it from a wet, slurry-like substance into a more manageable and less voluminous material. This process holds substantial importance for several reasons:

Volume Reduction:The primary benefit of dewatering is the significant reduction in the volume of sludge. Removing water from sludge leads to a reduction in its weight and volume, which lowers transportation and disposal costs. This is particularly important as sludge disposal can be expensive, and reducing the volume makes it more cost-effective to handle and transport.

Cost Savings:As mentioned, dewatering reduces the weight and volume of sludge, which translates to lower transportation and disposal costs. Since many wastewater treatment plants and industries have to manage large quantities of sludge, even a slight reduction in volume can result in substantial cost savings over time.

Resource Recovery:Depending on the specific characteristics of the dewatered sludge, it might be suitable for further processing to recover valuable resources.

The Belt Filter Press (BFP-L) is an industrial machine, used for solid/liquid separation processes, particularly the dewatering of sludge in various industries.

Brought to India with the help of a technical collaboration between Krofta Engineering Limited and AJV Engineering Ky. in 2007, it is a continuously operating double belt dewatering machine. The presses are designed for dewatering different kind of sludge by means of progressive compression between two permeable belts. Liquid sludge is conditioned by adding polymer to obtain the separation between liquid and solids. This operation is performed in an in-built flocculator tank with an agitator. Sludge flows from the flocculator to the distributor of the machine, where the sludge flows as an even mat to the gravity zone and then passes the low-pressure zone (also called wedge zone) before entering the high-pressure zone (also called S zone).

BPL