“Sarlin Balance compressed air management system makes it easy to keep abreast of the situation”
The journey of wood from forest to customer is largely controlled by
information technology: Automation, simulation models, light barriers
and sorting by camera are the order of the day at Raunion Saha sawmill,
where production technology and data systems are under constant
development. The sawmill uses great amounts of compressed air which it
buys as a utility from Sarlin. The sawmill staff no longer manage
compressed-air issues by walking into the compressor room, but by
watching Sarlin Balance data on screens and mobile phones.
The view is fundamentally different from what it was when Einar Raunio
started his sawmill at the rapids of Paimionjoki in 1909, even though
the mill remains a family business.
“Our oldest equipment now is from the 1990s, while our newest dryers
were launched last summer. We are constantly renewing the systems and
keeping up to date,” says the Factory Manager.
“We employ about 80 persons in the sawmill area of over 20 hectares. The
daily amount we saw can be up to 2,500 m³. The trucks carry about 50 m³
of timber each, meaning as many as a hundred trucks a day. About two
thirds of our production is exported: mainly to Europe, but also to
Northern Africa and Japan.”
The sawmill uses compressed air in its heating plant, cleaners, barking
plant and the actual sawing line and dryer. The timber is sorted into
compartments using compressed air. The trimmer especially requires great
amounts of air momentarily when the blades move up and down. When a
board is rejected, all 21 blades move simultaneously, cutting the board
into energy wood.
“In terms of compressed air, the difference between a sawmill and
process industry is that the fluctuations in air demand are sudden. The
demand soars from minimum to maximum in an instant when the mill starts.
Speed-regulated compressors are capable of meeting the demand
“Our earlier compressors responded to the fluctuations poorly; their efficiency was low, and they wasted electricity by idling.”
“About five years ago, we put our old compressors under Sarlin Balance
control, which improved the situation but was not enough to yield
savings in energy consumption.”
The compressor room now houses three speed-controlled screw compressors
and three adsorption dryers. Two compressors are enough to produce the
compressed air, and the third one is a stand-by unit. All three are
engaged in sequencing, so that they keep warm in winter as well. The new
compressors were placed in the old compressor room. The company
upgraded the cooling ducts in the room, but some further improvements
were also required.
“The service staff participated in the planning excellently; several
drawings were made. The room is small but very high and requires wide
To avoid freezing, the sequencing of the compressors was made more
frequent by Sarlin Balance control. Sarlin Balance keeps the pressure
level steady. The long pipe systems require a pressure of 6.5 bar, but
the company is searching for ways to drop the pressure on weekends.
“Sarlin Balance makes it really easy to keep abreast of the situation in
compressed air network; you can see the events of the last two months
immediately, and older data is available after only a few clicks.”