The first steam engines and boilers made in Finland came into use at the turn of the 1840s. Use of steam was initially concentrated on production of mechanical energy. In industry, the first to use the steam engine as power source were textile factories. By 1875, there were already 741 steam boilers in use, of which 545 were purely for machines. The first to generate electricity using steam was the Finlayson factory in 1882. In the heyday of steam engines, the 1800s, steam pressures, temperatures and boiler steam outputs in Finland remained modest; the highest steam pressure of a machine working by land steam engines was 12 atmospheres.


The early pulp mills needed relatively little mechanical energy, but steam was required for the manufacturing process. The first Jämsänkoski pulp mill used steam for drying the pulp and generating power, as well as the cooking process. The steam boiler room situated on the east side of the factory housed two fire-tube boilers. Their working pressure was 5.7 atmospheres. The logs used as fuel were fed by hand onto flat grates. There was also a locomobile, a steam engine and steam boiler combination, for running the drying machine. The bleaching unit completed in 1895 had its own steam engine.

A steam engine was purchased for the drying machine for the new pulp mill, built after the fire. Three small fire-tube boilers and one Steinmüller water-tube boiler were installed in the boiler room. These produced steam for cooking, bleaching and drying, as well as for heating the factory. The boilers also generated the steam required by the steam engine of the drying machine and the ancillary steam engine in the chipping section. The old fire-tube boilers were replaced in the early 1900s by Steinmüller and Babcock & Wilcox water-tube boilers.

In 1913, the pulp mill acquired a 300 horsepower vertical steam engine manufactured by Tampella. The machine was massive, with its flywheel alone weighing 6,000 kg. Its function was one of power engine for the surrounding factory sections at times of water shortage. The machine was custom-built and the first of its kind manufactured in Finland. It worked well, but used a lot of steam and was dangerous to handle.


A steam engine was installed at Patalankoski paper mill in 1900, and at Hovilanhaara paper mill, completed two years later, a 35 horsepower Golzern steam engine to operate vats and pumps. A decade later, little steam engines and water turbines had been installed all around the works uneconomically in energy conservation terms; 11 steam engines, with a combined output of about 1,500 horsepower.

To save firewood, one of the steam boilers was equipped with a so-called vertical grate, for burning tree bark, sawdust and other combustible wood waste. In the 1910s, the pulp mill steam boilers were equipped with chain and angled grates, so that more economic coal could be used as fuel. A steam accumulator was also purchased, in which energy could be stored during periods of lower steam consumption, to be used at peak periods. Thanks to these reforms, firewood consumption at the factories was cut by half.

The increased pulp and paper production in the 1920s increased the need for steam. Jämsänkoski acquired two 25 atmosphere Babcock & Wilcox steam boilers, with a fire surface of 350 m2. The high pressure steam boilers were updated, so that wood chip and coal could be used simultaneously as fuel. The low pressure boilers were gradually set aside as reserve boilers.

The first steam turbine, a Laval condensing turbine, was purchased for Jämsänkoski in 1926. It replaced five old steam engines. The turbine was positioned in the old steam boiler house at the Hovilanhaara paper mill. A few years later, a 1,300 kW counter pressure turbine was obtained. Counter pressure turbines were developed at the end of the 1910s, but their use became common only a decade later, when steam boilers exceeded pressures of more than 20 atmospheres. Counter pressure turbines were more economical than condensing turbines, as steam exiting at 3 - 4 atmosphere pressure could still be utilised for drying paper and pulp. The combined output of the Jämsänkoski steam turbines was 3,800 horsepower, and they generated the bulk of the electricity required by the factories.

The thermal energy necessary for generating steam was produced using different fuels. They varied according to price and availability. In the 1950s and 60s, coal was the most important fuel. Use of oil began to increase from the mid-1950s. The third most important source of thermal energy was wood. Use of wood was particularly prevalent at Kaipola, as the Olkkola sawmill next-door supplied sawmill waste. The waste liquor evaporation and incineration plant, completed at Jämsänkoski in 1969, used cellulose waste liquor as fuel, evaporated in a five-stage vacuum evaporating plant. The remaining solid matter was burned in steam boilers. Jämsänkoski also used a so-called electric boiler to generate steam when electricity was particularly cheap.

Link:  How a steam engine works [Finnish only]