Case: Westas Raunio Sawmill

WOOD INDUSTRY

Case: Westas Raunio Sawmill

“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 instantly.”

“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 exhaust ducts.”

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.”