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Case studies

Large-scale biomass boiler

Design and manufacture in Varkaus. Andritz is one of the world’s leading suppliers of industrial plants, systems and services for pulp, paper and energy industry. The company supplies products for wood processing, fibre analysis, chemical recovery, mass flow and energy production applications.

Andritz Group is an international corporation headquartered in Austria. The expertise and process know-how of the Finnish subsidiary play important roles in the group’s worldwide business. The Finnish subsidiary is headquartered in Helsinki, and it has offices in Varkaus, Hollola, Kotka, Savonlinna, and Tampere.

Utilisation of biomass fuels

ffor green energy production has become an increasingly important issue. Typically, wood biomass in the form of chips, bark and sawdust has been the fuel of choice.
More recently, different short rotation crops such as reed canary grass and willow can be seen. The biomass fuels are very reactive and high in volatile content which make them particularly suitable for bubbling fl uidized bed combustion processes.


Bubbling fluidised bed boiler for biomass fuels

Main components and systems:

  • 1. Bubbling fluidised bed furnace
  • 2. Fluidising grid
  • 3. Solid fuel feeding system
  • 4. Bed material dosing system
  • 5. Superheaters
  • 6. Economizers
  • 7. Flue gas air preheaters
  • 8. Drum
  • 9. Bottom ash system

Warkaus Works

is an engineering company based in Varkaus, Finland that manufactures pressure-bearing components for environmentally friendly power plant boilers and industrial boilers. The company’s products comply with the ISO 9001 and ASME quality standards. The company is co-owned by Andritz and Foster Wheeler Energy. Warkaus Works is headquartered in Varkaus, Finland, next door to Foster Wheeler. The company’s production and office facilities measure approximately 14,000 square metres, and most
sections of the manufacturing process are automated.

Over 90 percent

of products are exported. Market areas are Europe, North and South America, Asia and Oceania. Company’s pressure-bearing components include super heaters, furnace walls, furnace lower parts, grids, economizers, boiler banks, separators and headers. Products are used in fluidized bed boilers (circulating fluidized bed and bubbling fluidized bed boilers), recovery boilers, waste heat boilers and biomass boilers.

Andritz Fluidized Bed Boilers for pulp & paper and power industries


Fuel flexibility

  • Wide variation in moisture content and grades of fuel

High efficiency

  • Complete combustion with low unburned carbon in ash

Low environmental emissions

  • Effective CO and NOx reduction

High reliability and availability

  • Simple structure, no moving parts
  • Conservative design, high quality components

Boiler range

  • Steam flow: 40 - 400 t/h
  • Fuel input: 40 - 350 MWth
  • Steam pressure: 20 - 150 bar
  • Steam temperature: up to 540 °C

Technology

  • Bubbling Fluidized Bed (BFB) combustion
  • Single-drum, natural circulation steam boiler
  • Membrane-walled, gas tight construction
  • Water-cooled fluidizing grid
  • Fuel feeding above the bed

Fuels

  • Wood biomass (chips, bark, sawdust),
  • Recycled wood,
  • Energy cultivates,
  • Sludges
  • Peat
  • Coal (< 20% of total fuel input)


Varkaus facts

 

  • A market town was first established in the current location of Varkaus in 1929.
  • Varkaus was given town status in 1962.
  • Varkaus has a population of approx. 23,000 people.
  • Varkaus has a surface area of 524 km², of which 139 km² is water.

Location

  • Varkaus is located in the Northern Savonia region in Eastern Finland.
  • Varkaus is situated at the junction of two of Finland’s main road transport routes.
  • Varkaus is within easy access of Saimaa Canal, the most extensive and most trafficable inland waterway network in Finland.

Varkaus is located

  • 76 kilometres from Kuopio,
  • 125 kilometres from Jyväskylä,
  • 118 kilometres from Joensuu, and
  • 318 kilometres from Helsinki.


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