Axioma Servisas company completed the 423 thousand euros project at the Enefit Power shale oil plant near Narva, Estonia. The company carried out the overhaul of the Enefit-140 retort furnace, weighing as much as 200 tonnes.
“This is another specialised project that we have promptly and successfully completed at the shale oil plant. A team of 20 specialists from Axioma Servisas and a partner company were working on this project, performing welding work around the clock, in two shifts. In 2023, we hope to win a similar tender for the repair of another retort furnace operating in this plant,” said Artūras Lopeta, CEO of Axioma Servisas.
The team replaced two support steel rings that surround the cylindrical furnace. The overhaul of the four roller bearings, rotating the furnace, was also carried out. This required a 15-meter-long and 5 meters in diameter furnace operating at a height of 13 meters to be lifted off the roller supports. All the works were performed with the retort lifted.
No shortage of challenges
“The work was complicated not only by the weight of the furnace and replaceable parts, but also by its position – there is little space around this equipment and the ceiling is low. Moreover, we had to find solutions for placing the rollers weighing 10 tonnes each on a floor with a maximum permissible load of only 1 tonne per 1 square meter,” said Darius Imbrasas, Head of the Service Division of Estonia Eastern Region at Axioma Servisas.
To protect the floor from caving in, the specialists laid special steel sheets on which the rollers were then placed. Axioma Servisas also used heavy-duty equipment to remove the furnace and replace huge parts – four 200-tonne hydraulic lifts.
“Perhaps the main challenge has been to dismantle old equipment that has not been moved for over 25 years. Another one was returning the repaired and refurbished retort furnace to exactly the same place and aligning it,” added Imbrasas.
Precision is required because the retort furnace must rotate continuously in order for the heated raw material entering it at one end to mix and slide along the entire length of the equipment towards the outlet. A similar technology is used in cement production.
Designing a giant
Axioma Servisas is not a newcomer to the oil shale industry developed in Estonia – the company has performed work for all the country’s major companies. Lithuanians are also engaged in servicing various technological equipment at the Enefit Power shale oil plant.
The company is in charge of the design, production and installation of a giant furnace at the new shale oil production plant Enefit 280-2, which is currently under construction. It is estimated that this product with the length of more than 17 meters and over 6 meters in diameter will become one of the largest retort furnaces operating in the oil shale industry worldwide. In May last year, Axioma Servisas signed a nearly 9 million euros contract with Enefit Power, a company building the plant.
The Estonian state energy group Eesti Energia, which unites more than 20 companies, operates on the international stage under the name of Enefit. The group is the largest energy producer in the Baltic States.
