A New Dimension Of Biological Treatment: Esmil Group Supplies 54-Metre Radial Scrapers For The Vilnius Wastewater Treatment Plant

The municipal wastewater treatment plant in Vilnius, which handles nearly one-third of all wastewater generated across Lithuania, has completed a comprehensive, multi-stage modernisation programme.

As a result of this investment, the facility has become one of the most advanced wastewater treatment plants among the Baltic countries, meeting the strictest environmental standards.

The scale of the entire project is best illustrated by the plant’s designed maximum capacity during rainy period – 17,000 m³/h.

Esmil Group became part of this milestone project – we were selected by the general contractor, UAB “ARGINTA”, as the supplier of key equipment for the biological treatment stage. As part of the scope, we delivered three large-scale radial scrapers complete with all auxiliary equipment.

An Engineering Challenge On A Grand Scale: Radial Scrapers For 54-Metre-Diameter, 6-Metre-Deep Clarifiers
Our task was to design and manufacture radial scrapers for three primary clarifiers of impressive dimensions: 54 metres in diameter and 6 metres deep.

Such large structures had to be engineered to operate under high hydraulic and mechanical loads, characteristic of the flow conditions at this facility.

At the same time, precision of fabrication was of utmost importance – particularly when assembling the bolted bridge sections, which had to maintain perfect linear alignment over a 54-metre span without the slightest deviation.

The scrapers were made entirely of stainless steel suitable for operation in a highly aggressive wastewater environment: the submerged components were fabricated from AISI 316, while the parts above the liquid level were made of AISI 304. Each scraper weighs 23 tonnes.

Each supplied scraper set includes:

• Floating sludge extraction system,
• Weirs,
• Scum baffle,
• Weir cleaner,
• Central deflector.

Floating Sludge Extraction System
One of the key components of our scrapers is the advanced flotating sludge extraction system, developed in cooperation with our long-term partners at PROBIG.

This solution ensures continuous and efficient removal of floating contaminants from the liquid surface. These are conveyed by a spiral mechanism to the scum chamber, where a submersible pump discharges the collected material.

Summary
We successfully met the main challenge of this project – the impressive dimensions of the 54-metre clarifiers.The radial scrapers designed and manufactured by ESMIL were precisely tailored to the plant’s requirements and seamlessly integrated with its infrastructure.

We are proud that our equipment has become part of a project of such strategic importance.This achievement demonstrates that the ESMIL team is capable of meeting even the most demanding engineering challenges – combining expertise, experience and meticulous attention to every structural detail.