Dieffenbacher acquired the remaining shares in the company in 2003 and in that year the company was renamed SPE and incorporated ‘Dieffenbacher Group’ in its logo. The product range has moved on substantially as well and now includes dryers for MDF, particleboard and OSB and the latest innovation, the super-heated-steam fibre dryer, as well as heavy material graders and fibre graders, including Schenkmann & Piel’s well-established air grader for particleboard. In the product range there is also pneumatic equipment and consulting and engineering services for new, and for upgrading older, lines. Meanwhile the management has also changed in recent years. Dr G√ľnter Kuhn was appointed managing director in April 2005, having previously been technical director at Richard Kablitz & Mitthof GmbH, a manufacturer of grate and energy systems.
In September of the same year, Belgian Didier Goesaert joined SPE as sales and marketing manager, having worked within the Dieffenbacher Group since June 2004. Before that he worked for panel maker Agglo. Stefan Mikaelsson was appointed deputy managing director of SPE in May 2007, having previously been managing director at Metso Panelboard’s German subsidiary in Hanover (recently sold to Siempelkamp). Turnover for SPE in 2006 was e13.5m and 2007 was heading for e18m at the time of my visit in late September. The expected figure for 2008 is e25m, or in other words, approximately doubling turnover in two years, excluding the energy systems.
Fibre dryers account for around 50% of that turnover, particle/OSB dryers 40% and graders 10%.
The company’s markets are truly global, with recent dryer orders coming from Poland, China, Russia, Romania, Latvia, Turkey and Venezuela. Eight of these were for MDF lines, three for OSB and one for particleboard.
In fact the line for PDVSA of Venezuela will be supplied as part of a complete plant from Dieffenbacher and will be the first continuous OSB line in that country. The first OSB dryers from SPE were supplied to Masisa Brazil (two plants) and Agglo of Belgium, all in 2000.
"We are also expecting to reach 10 complete projects with fibre dryers and graders by the end of this year," said Mr Goesaert.
For the first time, SPE will supply a fibre dryer complete with energy plant to Partner Tomsk in Russia under its own complete responsibility.
"Energy plant and dryer together will be one contract for most projects in the future," predicted Mr Goesaert confidently. "We are making more and more quotations for this kind of complete plant concept."
The new super-heated steam fibre dryer offered by SPE operates in a ‘closed loop’ system which means there are no emissions – particularly important to the North American market with its MACT (Maximum Achievable Control Technology) emissions regulations.
Wet fibre is injected via the blow-line and dried to the required moisture content by continuous, pressurised, super-heated steam circulation.
The final moisture content of the fibres is achieved during the dwell time in the dryer tube, which ends in a cyclone.
Dried fibres are discharged through a rotary valve located downstream of the cyclone. The steam is then re-circulated through a heat exchanger for super-heating before being re-used.
"The advantage is less heat demand, leading to an energy saving of 40% or more," said Mr Goesaert.
The first two industrial plants are in operation. One is at Kronotex’s K-Face line in Heiligengrabe, where it dries fibre for insulation panels, while the second is employed in the animal feed industry.
Currently, the dryers can run at four tonnes per hour of fibre, but the company intends to increase this to 10 tonnes.
The company also has a different take on drying with its vertical combustion chamber.
"The increased use of recycled wood means increased silica and this has to be cleaned out of a horizontal dryer," said Mr Goesaert. "With our vertical chamber you have automatic extraction via a rotary valve and can run the dryer without cleaning shut-downs for two to three months."
But SPE is not just talking about the effects within the dryer. "The quality of a panel is not in the press alone," said the sales and marketing manager. "It is in the preparation of the raw material and correct drying to the right moisture content."
With regard to high-capacity dryers for OSB and particleboard, Mr Goesaert believes there is a demand for one big reliable dryer, rather than multiple smaller dryers. "You don’t have two presses so why two dryers?" he asked. "We supply one of the largest drum dryers on the market, with a 7m internal diameter and the longest so far is 37m.
"The capacity trend for panel mills has been upwards in recent years and our particleboard dryers are up to 75 tonnes per hour (tph) now. The increased use of recycled wood means lower initial moisture contents – hence the bigger capacities. For OSB, the figure is around 48tph."
The SPE dryer is installed at ground level and employs a large discharge box for OSB to reduce the amount of broken strands. It also offers explosion protection to ATEX rules, with explosion panels. The company also claims there is no plugging or sticking of the strands, as well as low maintenance requirements.
The internals of the dryer have also been the subject of research and development, resulting in SPE’s ‘Omega’ support disc system. The Omega disc acts like a spring, so avoiding breakage of drum internals under stress, explained Mr Goesaert.
The internals are pre-assembled as modular sections on site and then inserted into the drum and welded to the drum walls at the Omega disc/drum interface.
There is a gap between each of these modules to allow access for inspection and maintenance.
This is all claimed to give a stable drum construction, flexible mounting positions for the internals and shorter assembly time, while the drum interior is claimed to offer 85% open space.
There is also no central ‘axle’ as in other dryer types, and this avoids ‘bunching’ of the strands in the centre of the drum.
The drum runs on a gear ring mechanism and ‘paddles’ between ring and drum absorb expansion of the hot drum.
The company has supplied 130 drum driers to the world market to date.
Air graders are an important product range for SPE, with 420 supplied worldwide, and it is particularly proud of its particleboard air grader, claiming that its cylindrical form avoids any material adhering to corners as in rectangular section graders.
It splits the incoming material into two fractions – acceptable and reject. The latter includes high density contaminants,
needles and so on. The material to be graded enters the suspension chamber via a rotary valve and central tube. Rotary arms then distribute the material evenly over the perforated plate towards the base of the grader, through which the grading air is drawn. Different grades of separation are achieved by the variable air velocity.
The heavy fraction moves to the outside of the suspension chamber and leaves via another rotary valve, while the lighter fraction is suspended in the air stream and separated from it in high-efficiency cyclones (‘Hurriclones’).
The largest of the new generation of these graders has a 16m2 surface area and a capacity of more than 52tph for core layer and 28tph for surface layer, in the one grader.
The SGF-Air Grader for fibre is also offered by SPE, to separate out wood residues, glue lumps, fibre deposits, latex and minerals.
Flash driers for fibre complete the range of dryers for all composite panel types. These flash tube driers have capacities up to 60tph mechanical throughput.
They are offered with or without air recirculation as one- or two-stage dryers, but SPE says that recirculation can save around 25% of thermal energy.
Dust collection is by cyclones, with wet electrostatic precipitator or recuperative thermal oxidiser.
Looking at the company today, it is evident that although SPE is now part of the Dieffenbacher group of companies, it has retained the link with the founding business established my messrs Schenkmann and Piel 30 years ago and it still makes the original type of product – air graders. It’s just that it has added a lot of other products to that founding concept.