I-001-FI-015-EN
mml
● ● ● Particularity : efficient on-site use of wood waste from the wood products industry
The wood energy Trail
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Passenans : Turning wasted wood from a box factory into energy Putting by-products to good use
Fuel supply
Photo AJENA
The company Marotte is a box factory employing 35 people. The production is divi-
The fuel used is produced entirely on-site. A central vacuum system connected to each workbench feeds a vertical silo 8 metres in diameter, with a capacity of 480 m3, which gives plenty of room to store all the waste produced (400 m3 of shavings and 200 m3 of bits of wood per year). Large bits of wood are ground in a small tub grinder before joining the shredded wood in the storage silo. The wood is removed from the silo by means of a horizontal worm screw on the silo floor. It is then transferred via a pneumatic system to the feeder silo leading to the boiler. To avoid the production of high levels of dust at the end of the pneumatic transport process, the reception hopper is fitted with 24 sleeve filters. All the wasted wood produced by the company is used in the boiler.
A self-operating boiler
ded between boxes and small assembled articles in wood. To make the best use of the large amount of bits of wood, shavings and sawdust it produces, the company decided in 1993 to invest in an automatic wood-fired boiler. The size of installation was chosen to use all the waste produced, taking into account the growth of the company over the years. Apart from the benefits it provides in heating the premises, the investment is especially worthwhile from a financial point of view because of the presence on the site of facilities for drying and varnishing wood, both of which use up a great deal of energy.
Information on the community The storage silo
Programme of the Jura Department
• Altitude : 320 m, • Population : 296 inhabitants, • Forest : 236 hectares.
The Nolting boiler has an output of 930 kW and a boiler furnace with underfeeder screw, and takes fuel with a moisture content of up to 35 % of gross weight. The combustion chamber is generously proportioned and is lined entirely with moulded bricks. Its vault radiates heat, creating turbulences which perfect the combustion process. The heat exchanger with vertical plates, and four stages of heat exchange for the flue gases prevents the build-up of dust and ensures a high thermic output. A centrifugal dust-remover (multicyclone) filters the smoke, and a worm screw clears the ashes from the combustion chamber automatically. The boiler provides enough warmth for a drying facility of 220 m3 where the temperatures can reach 60 to 80 °C (for drying beech), a varnishing room where the air is renewed regularly, and of course the workshops and the offices. In total, the surface heated is in the region of 3,000 metres square.
© ITEBE- july 1999
Photo AJENA
General view of the factory