Case story

Energy saving ambitions drive HEINEKEN ZAGORKA Brewery ahead, with VLT® FlexConcept

The ZAGORKA brewery was founded more than a century ago and over the years it has become a symbol of the Bulgarian town of Stara Zagora.

— Thursday, 26 November 2015 By Danfoss Drives

The ZAGORKA brand has grown to be the favourite beer of generations of Bulgarians. In 1994 ZAGORKA became part of HEINEKEN Company, and since then ambitions have expanded further. Over the last 20 years, more than

EUR 133 million has been invested in the brewery in Stara Zagora, modernising operations and increasing production capacity. It is now one of the most advanced breweries in Central and Eastern Europe. 

Focus is on the areas that can make a difference: 

  • Sustainability – minimising environmental impact
  • Water consumption
  • CO2 emission 
  • Responsible energy consumption 

As part of HEINEKEN, and as a leading Bulgarian brewery, ZAGORKA is committed to developing its business in a sustainable and responsible way. 

In order to achieve its ambitious sustainability goals, ZAGORKA has actively renovated its brewery equipment and facilities over the last 20 years.

One of the main modernisation projects was an upgrade of the gear motors on a glass bottle filling line to more efficient motors, performed in 2013. The main objectives of the project were upgrade to higher performance, flexibility, and reliability of the drive systems that have a direct impact on production cost. Ultimately these factors impact the competitiveness of the products. High hygiene levels were also an important consideration as the motors operate in the wet part of the filling line, where demanding hygienic compliance applies.

HEINEKEN ZAGORKA chose VLT® FlexConcept® to meet all these demands. In total, around 40 motors were replaced stepwise in the wet (hygienic) part of the filling line.

The original system comprised a helical gearbox with chain and asynchronous motor. The new drive system consists of the VLT® OneGearDrive® where drive and motor are integrated into a single unit.


Helical gearbox with chain and asynchronous motor


VLT® OneGearDrive®


HEINEKEN chose the VLT® OneGearDrive® solution over competing alternatives due to its unique high performance, above and beyond the aims of the retrofit project:

Higher system efficiency
A helical gearbox with an asynchronous motor and a chain as an additional gear ratio has an efficiency of about 62.5% compared to 89.4% for VLT® FlexConcept®. The immediate effect is energy savings of up to 25%.

Cost-efficient mounting
Installation is easy and fast. The VLT® OneGearDrive® is directly mounted on the conveyor shaft, so chains are no longer required. The elimination of chains also means less maintenance and fewer spare parts are required. If there is a breakdown the VLT® OneGearDrive® is quickly and easily replaced, minimising downtime.

Easy to clean
The hygienic design with no cooling fins, fan, or sharp edges makes the VLT® therefore all hygiene requirements are completely fulfilled.

Reduced storage cost
For maintenance purposes, storage of only one gear ratio and one frequency converter size is required for this section of the line. Previously storage of up to 10 different components was required. The elimination of variants and reduction in number of components gives a dramatic reduction in warehousing cost.



The ZAGORKA brewery already has a history of positive experience with Danfoss, with cabinet-mounted VLT® 5000 and VLT® AutomationDrive frequency converters providing central motor control. Because the existing drives and the new VLT® FlexConcept® components share a common operation principle, commissioning and integration into the existing setting was very easy to implement.

Currently 25 new units comprising VLT® OneGearDrive® controlled by VLT® AutomationDrive FC 302 are Installed and running smoothly to deliver the new energy savings. So HEINEKEN ZAGORKA is completely satisfied with the performance of its new Danfoss VLT® FlexConcept® solution.


ZAGORKA is a leading national premium beer brand, popular when it is “time for something special”. 

Produced in and named after the city of Stara Zagora in central Bulgaria, ZAGORKA is rich in history and brewing tradition. The HEINEKEN ZAGORKA brewery is one of the oldest and most respected breweries in the country. Founded in 1902, it is today, more than 100 years later, the biggest and technically most advanced brewery in Bulgaria. Currently it employs 510 people in Stara Zagora.



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