Design and construction of Aravete 0.85 MW boiler plant

Tamult designed and delivered a fully operational boiler plant in Aravete as a turnkey solution, in accordance with the technical specifications of the public procurement. The aim of the project was to ensure a reliable, flexible and fully automated heat generation system that can adapt to changes in fuel quality and load and meet the needs of the local district heating network.

The main load of the boiler plant will be covered by a biofuel boiler with a nominal capacity of 0.85 MW, designed to operate with wood chips, bark and sawdust in the moisture range 30-55%. The boiler operates automatically in the load range 30-100%, allowing on/off mode at low loads. The system operates at 105/90 °C, with a maximum temperature and pressure of 110 °C/6 bar, achieving an efficiency of at least 85% according to EVS EN 12953. The boiler is equipped with an internal circulating pump with frequency converter to prevent low temperature corrosion.

To cover peak and reserve loads, Tamult installed a liquid-fired boiler with a nominal capacity of 0.8 MW and an efficiency of at least 91%. The boiler is equipped with a heavy oil burner, multi-stage control and fully complies with CE marking requirements.

A 200 m³ biofuel storage facility was built as a separate fire compartment for fuel handling, allowing the boiler to operate at full load for about one week and at average load for up to two weeks. Fuel is received directly from the truck without the need for an additional loader. The warehouse scraper floor is equipped with a water-fired underfloor heating system, controlled by a floor temperature sensor, with a minimum power of 250 W/m², ensuring reliability even in difficult winter conditions.

The waste management solution is designed to be fully automatic. The boiler house is equipped with a 10 m³ hermetic ash container with a levelling plug and a fill level sensor. All connections are dust- and leak-proof and the container is serviceable from the ground and lockable, facilitating safe and efficient handling.

The success of the project is also confirmed by the contracting authority’s assessment of the cooperation and the result:

“We are very grateful to Tamult AS. The construction of the Aravete boiler house has been one of the most worry-free constructions for the contractor. We have received a boiler house that meets our needs on the agreed terms and at a reasonable price.”

Andres Sapas, AS Järva Haldus, Member of the Management Board

The result is a state-of-the-art biomass-based district heating solution that meets stringent technical requirements, ensures high efficiency and reduces long-term operation and maintenance costs. The project confirms Tamulti’s ability to carry out complex boiler solutions from design to delivery of a complete and reliable system.