Shredding and burning of residual wood with BAFA subsidy
With a WEIMA WL 4 single-shaft shredder, a sophisticated screw system and a wood chips heating system, the German carpenter Bernd Kreutner in Bahlingen uses the own waste wood such as roof battens, offcuts and pallets sustainably to heat the shop buildings.
German family business
For almost 20 years, Bernd Kreutner, his family and eight employees have been offering carpentry work of all kinds in Bahlingen am Kaiserstuhl in Baden, Germany. In addition to timber frame construction, new buildings, renovations and hall construction, the company specializes in timber buildings in historic villages. This generates about 80 cubic meters of residual wood per year.
About Kreutner Carpentry
In the past, we used to burn some of the accumulating wood in th stove of the central heating system and dispose of some of it. In doing so, the large area taken up by the wood residues was particularly troublesome. But the cost of disposal wasn't without its problems, either.
In order to finally find a remedy and to be able to recycle the wood residues in a cost-efficient and sustainable way, Bernd Kreutner decided to buy a shredder. Since 2020, a WEIMA WL 4 single-shaft shredder has been installed in the large hall of the carpentry company – with a view of the neighboring vineyards.
WL 4 – proven chipper for wood scrap
The WL 4from WEIMA is a proven shredder for processing all types of wood waste. With a rotor diameter of 260 mm and a working width of 600 mm, neither roof battens nor sections or pallets with nails are a challenge. In addition, the chipper is particularly user-friendly thanks to a Siemens PLC control with touch display.
The shredder can be filled both manually and via forklift. For this purpose, a special hopper was built which ensures that the entire wood load lands inside of it securely. Bernd Kreutner did not only opt for a shredder to reduce the waste wood volume.
It was also possible to reduce the amount of work involved in handling the residual wood. The shredder is filled five to six times a week to shred the accumulated wood. It then takes about 20 minutes to shred a full load.
Everything from a single source: tailor-made system, comprising shredder, and conveyor technology
What is special about the Kreutner carpentry shop is that the shredded wood chips are conveyed upwards out of the workshop hall via a screw conveyor system. The magnetic separator, which separates nails and other metals from the wood chips, is located on the roof. The separated metal is fed back into the hall via a second pipe and collected in a container. The metal residues are then recycled.
Ready for cold winter days
The shredded residual wood is transported by a screw conveyor to the 80 cubic meter chip bunker for storage. In the cold months, the residual wood can be used in the central heating system to generate heat for the halls as well as the Kreutner family’s home.
Clear case: screw conveyor instead of exhaust system
There were many reasons why Mr. Kreutner opted for an auger design and against an exhaust system. On the one hand, the use of slowly rotating screws makes it possible to fill the bunker without pressure. This not only reduces the risk of fire, but also ensures lower insurance costs and requirements. In addition, screw conveyors are extremely energy-efficient and significantly quieter than a system with suction.
BAFA subsidy makes it possible
The decisive factor in favor of a shredder from WEIMA was not only the good advice provided by Sales Director Fred Haller, but also the expert support in planning the complete system. Through a program of the German BAFA, the Kreutner carpentry company was able to secure a subsidy for the purchase of the grinder, a new Hargassner wood chip heating system, the construction of the chip bunker and the peripheral equipment. Now the carpentry business is well equipped for the years to come.
