Everything you need to know about lamella clarifiers
What is a lamella clarifier and how does it work?
This is a water treatment equipment used to clarify water by separating suspended particles. Industries and wastewater treatment plants frequently use lamella clarifiers to improve the quality of treated water.
The lamella clarifier consists of 3 mm thick anti-clogging plates to facilitate water flow. Suspended particles are retained on the surface of the plates and accumulate as water circulates.
Its operation is based on the difference in density between suspended particles and water. Centrifugal pressure pushes lighter particles towards the surface, while heavier ones remain in suspension.
When suspended particles gather around the surface of the blades, a quick-drain system evacuates them.
Which benefits does using a lamella clarifier offer compared to other types of clarifiers?
Using lamella clarifiers has many positive aspects compared to other types of clarifiers.
- The lamellar decanter provides a better sludge index by effectively separating suspended particles. The inclined plates facilitate slow water flow. Each suspended particle has enough time to accumulate on the surface.
- Moreover, lamella clarifiers provide a lower Hazen speed than other types of clarifiers. This Hazen velocity is an indicator of the quality of clarified water, and the lower it is, the clearer the water. It is measured by the sludge index.
- Another benefit of a lamella clarifier is its simplicity of use and maintenance. The lamellae can easily be cleaned and the sludge is removed by a draining system.
Ultimately, the lamella clarifier is a reliable clarification system for a variety of applications. Suitable for wastewater treatment plants, industries and fish farms
What are the inconvenients of using a lamella clarifier?
A lamella clarifier can be considered as the most efficient solution for sludge settling.
However, there are a few drawbacks to consider when using a lamella clarifier.
- First of all, a lamella clarifier is generally more expensive than a conventional clarifier. This is because of the lamellae inside.
- However, since the lamella clarifier is about 10 times more efficient than a conventional clarifier in terms of sludge index and Hazen speed, this is not a decisive argument.
- Another issue is the necessity to clean the lamellae. The thin lamellae (less than 2 mm) can collapse under the weight of the sludge, so it is necessary to clean them often. The clarifiers with the automatic lamellae cleaning option are more convenient and do not have this problem.
On the other hand, the inconveniences are somehow negotiable and depend on the needs and criteria of each user.
Design criteria for a lamella clarifier
The sizing criteria of a lamella clarifier are very important to ensure optimal efficiency of wastewater treatment.
- The Hazen velocity is an important criterion that defines the rate at which suspended particles are deposited on the walls of the decanter.
- The surface loading rate determines the minimum water supply. It prevents settling vortices being generated in the settler.
- The residence time indicates the duration of water contact with the clarifier walls. This is essential to ensure efficient particle separation.
How to maintain and clean a lamella clarifier?
Regular maintenance and cleaning of a lamella clarifier is necessary to ensure optimal efficiency of its operation.
If you have thin lamellae in your clarifier, they may bend under the weight of the sludge that accumulates in them. That’s why many manufacturers require weekly maintenance.
With thick lamellae like our clarifiers, cleaning is essential. However, this is only necessary if the performance on suspended solids decreases.
The purpose of cleaning the lamellae is to remove sludge and waste from the clarifier surfaces. This action ensures optimal water circulation and prevents obstructions. Cleaning can be done manually with a high-pressure cleaner. Alternatively, a built-in cleaning system can do this automatically.
Monitoring the operation of cleaning equipment on a regular basis is essential. What’s more, maintenance prevents malfunctions or damage to the clarifier.
The benefits of combining a lamella clarifier with a drum filter
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Open drum filter for sanitation
Filtering
The combined use of a lamella clarifier and a drum filter offers many advantages for industrial water treatment.
The lamella clarifier separates suspended sediments in water. The drum filter removes finer suspended solids. This combination results in clear and purified water, free of harmful suspended matter.
The major advantage of this combination is its effectiveness on highly contaminated water. Both sediment and suspended solids are treated at high rates. With their outstanding processing capacity, Lamella clarifiers can efficiently separate even the coarsest sediments. Drum filters, on the other hand, remove finer suspended solids. This combination of filtration technologies offers a comprehensive treatment solution for industrial water.
Combining a lamella clarifier with a drum filter is a cost-effective solution. It requires less maintenance and filter replacement than other methods. This makes this filtration solution particularly attractive for industrialists looking to reduce water treatment costs.
The benefits of combining a lamella clarifier with biological treatment
Combining a lamella clarifier with biological treatment is an advantageous choice for wastewater treatment systems.
The lamella clarifier separates suspended solids from wastewater. It removes suspended solids in the form of sludge, reducing the pollution load of biological treatment. Biological treatment is designed to break down the pollutants dissolved in the effluent by the action of micro-organisms. These micro-organisms then use these substances to live and reproduce with the pollutants as nutrients.
Treatment process include:
- Denitrification
- carbon elimination
In addition, adding a lamella clarifier improves the efficiency of biological treatment. This allows the system to function optimally. This ensures cleaner treated wastewater.
In addition, the combo allows:
- save space and energy, which also makes it economically advantageous
- reduce the environmental impact
Combining a lamella clarifier with a coagulation flocculation system is an advantage
The joint use of a lamella clarifier and coagulation-flocculation offers many advantages for water treatment.
- Coagulation-flocculation brings together suspended particles in water. Such particles aggregate to form large flakes, easily removed by the lamella clarifier.
- This clarifier has horizontal lamellae forming layers of decreasing density. They separate suspended particles more efficiently than traditional filtrations.
- Then, the lamella clarifier will be used to treat large volumes of water in a short time. As a result, it is highly prized for industrial applications.
- On one hand, the combination of these technologies produces high-quality clear water. On the other hand, this water is suitable for consumption, irrigation, and industrial production.
FAQ
What is the difference between a lamella clarifier and a conventional clarifier?
A lamella clarifier differs from a conventional clarifier by the presence of inclined plates that increase the settling surface. This allows for faster and more efficient clarification while occupying less floor space. On average, a lamella clarifier is 10 times more efficient than a conventional clarifier for separating suspended particles, thanks to a better Hazen velocity and an optimized sludge index.
In which industries are lamella clarifiers most commonly used?
Lamella clarifiers are used in various sectors such as municipal wastewater treatment, food processing, aquaculture, chemical industries, metallurgy, and quarries and sand pits. They are particularly appreciated when large volumes of water need to be treated with high efficiency and limited footprint.
Can a lamella clarifier be used with drinking water?
Yes, lamella clarifiers can be used for clarifying water intended for human consumption, provided that current treatment standards are respected. Coupled with coagulation-flocculation and disinfection, it effectively removes suspended particles before the final stages of potabilization.
How to choose between a vertical or horizontal lamella clarifier?
The choice depends on the available space, the flow rate to be treated, and the type of sludge. A vertical lamella clarifier is more compact and suitable for small spaces, while a horizontal model is adapted for larger flow rates. The ease of access for cleaning should also be considered, especially in industrial environments.
What is the average cost of a lamella clarifier and what factors influence this price?
The price of a lamella clarifier varies between €10,000 and €80,000 excluding tax, depending on its size, the material used, options (automatic cleaning, anti-corrosion coating, instrumentation), and the level of automation. The complexity of the project and water quality requirements also strongly influence the final cost.
