Lamella Clarifier

A lamella clarifier is a water treatment tank that removes suspended solids from water using a series of inclined plates. You’ll also hear these referred to as incline plate settling tanks, which describes the way the system works.

Water flows through the inclined plate pack, where solids settle onto the plates and slide into the sludge hopper. Clarified water carries on through the tank to the outlet.

The plate pack creates a large settling area within a fairly small footprint.

How does a lamella clarifier work?

Water carrying suspended solids enters the clarifier and flows between closely spaced inclined plates.

As the water moves through the plate pack, heavier particles settle onto the plates. The incline helps the solids slide into the sludge hopper – ready for removal. Clarified water then flows through the upper part of the tank and towards the outlet.

The basic principle is simple – give suspended solids enough area and time to settle out of the water.

Prime HL50 lamella clarifier operating at a quarry site

Why are lamella clarifier plates inclined?

The inclined plates increase the available settling area within a relatively small tank footprint.

Water flows between the plates as suspended solids settle onto their surfaces and slide towards the sludge hopper. That makes incline plate settling useful on sites where space is tight or a large settling pond isn’t practical.

What does a lamella clarifier remove?

Lamella clarifiers remove suspended solids such as silt and sediment.

But they don’t remove everything. Dissolved contaminants remain in solution and may need a different treatment process. Depending on the water and the discharge requirements, your treatment setup may also need chemical dosing, pH correction or oil separation.

That’s why understanding the incoming water comes first.

An HL50 lamella clarifier installed for on-site water treatment

What happens if water moves through a lamella clarifier too quickly?

A lamella clarifier still needs to give solids time to separate from the water. Push water through too fast and some suspended material may carry through instead of settling.

However, simply slowing the flow isn’t the whole answer. Incoming water conditions, solids loading, chemical treatment and the discharge quality you’re aiming for all affect how the system should run.

More flow doesn’t necessarily mean better treatment.

Settling tank vs lamella clarifier – what’s the difference?

Both use gravity to separate suspended solids from water.

A conventional settling tank gives solids space and time to fall out of suspension. A lamella clarifier adds a pack of inclined plates – which creates more settling area inside the tank.

Settling tank and lamella clarifier shown side by side

Where are lamella clarifiers used?

For site water treatment, lamella clarifiers are commonly used where water contains silt and other suspended solids. On the kinds of sites Prime works on, that often includes:

• Construction runoff

• Site dewatering

• Groundwater

• Dirty ponds

• Civil works where space for a large settlement area is limited.

What the full treatment setup looks like will depend on the water coming in and the quality you need at discharge.

Two Prime HL50 lamella clarifiers set up for on-site water treatment

How do you keep a lamella clarifier working well?

Lamella clarifiers need regular sludge removal, along with access to the plate pack for cleaning. Let solids build up and you reduce the space available for treatment – which can affect performance.

Prime's lamella units have accessible cleaning points and removable plates to make that maintenance easier.

Looking for a lamella clarifier for a project? Explore Prime's lamella clarifier range.

Related terms

Total Suspended Solids | Turbidity | Settling Tank | Coagulation | Settling Time | Flocculation | Sludge Hopper

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