Manufacturers' news

Thirteen consecutive years of ongoing successful cooperation to the benefit of demanding clients world-wide Jartek Invest Oy and Classen Apparatebau Wiesloch GmbH

3 September 2018

In May 2005, the Finish company Jartek Oy, nowadays Jartek Invest Oy, placed their first order with Classen Apparatebau Wiesloch GmbH. Ever since then, the two companies entered into a close partnership and supplied numerous systems over many countries in Europe, the United States, Canada, Japan and New Zealand.

Over a decade of close and trustful partnership is certainly a good and noble reason to make a detailed introduction of the two companies who have a lot in common: Besides continuously aiming for supporting their clients in the best possible way for their lasting business success, Jartek and CAW develop the projects together with their clients and build equipment to match with their needs and expectations. Receiving repeat orders from their clients is the best reputation a company can be awarded with – both, Jartek and CAW take pride in having many of such customers.

Jartek Invest Oy ( from Lahti was initially established under the name of SATEKO Oy in the late 50’s of the last century. Throughout the years there have been usual changes in their business orientation which were mainly acquisitions and sales of business lines. Along with the aforesaid there were some changes in name as well as in its legal business forms. Jartek’s two original product lines, timber drying kilns and sawn timber sorting lines, have been active until today and keep forming a substantial part of the company’s success.

Given the geographic proximity to the former Soviet Union, Jartek built complete sawmills in those countries. A typical sawmill then consisted of up to 30 lumber drying kilns. With more than a total of 1,500 installed drying kilns and many high-capacity automated sorting lines installed in world-leading sawmills, Jartek is regarded as an internationally recognized global player in this application sector.

In 1998 Jartek entered a new application: "ThermoWood®".

The thermally modified timber began its conquering of the world. Being part of this growth process with developing the associated special drying kilns and sophisticated control philosophy, Jartek has become the market leading systems manufacturer. Today their customers, producers of ThermoWood®, cover more than 50 % of the global fabrication of thermally modified timber. The rest of total production volume is shared with numerous other technologies.

Detailed information on the production process, remarkable properties and broad applicability of these durable and resistant wood products can be found at

Typical Jartek kiln for the thermal modification of sawn timber.jpg

Classen Apparatebau Wiesloch GmbH (, who just recently celebrated their twentieth anniversary on July 1st, has won a reputation worldwide for high-quality and reliable individually customized plants in the sector of high temperature process heating.

Often shortened to "CAW", the outfit located in the city of Wiesloch in the  Southwest of Germany, are specialists in engineering, construction and commissioning of complete plants for heat generation using heat transfer oils ("thermal oils"), heat storage and heat distribution in the temperature range up to and above 400° C. Besides that, CAW specializes in reciprocating grate technology, decentralized ORC power stations and thermal oxidizers for solid, liquid and gaseous waste streams.

Amongst many other prominent installations in virtually all industries all over the globe, the company has built the largest biomass-fired power generation systems installed to date: Four thermal oil heater systems in Canada, each with a nameplate thermal oil heating capacity of 28 MW and powering an ORC turbine with 6.5 MWel as well as one thermal oil heater system in the USA with a nameplate thermal oil heating capacity of 31.5 MW and powering an ORC turbine with 8.5 MWel.

CAW’s equipment supply for Jartek usually covers a complete tailor-made process heating system comprising of a thermal oil heater with three flue gas passages and integrated kiln off-gas incineration as well as a steam generator. The heaters / oxidizers are mostly fired with locally available fuels such as natural gas and fuel oils. Included in CAW’s scope are further all thermal fluid circulation pumps for primary as well as consumer oil circuits.

Typical CAW thermal oil heater_oxidizer and oil circulation pumpskids for a Jartekinstallation.jpg

Thermal modification of wood is an environmentally friendly and pure thermal process: The woody materials are modified by using solely process heat and saturated steam, no toxic or other chemicals are used nor needed. The wood extractives driven off the lumber during the modification process are captured, incinerated and turned into a vital part of the required process heat. The required heat energy can also be generated in a "green" way by utilizing the mills’ wood waste and residuals. The total energy consumption is approx. 20 to 30 % higher than in the standard wood drying process. Thermally modified wood products are recyclable in the same way as natural unmodified wood as well as the use of thermally modified wood products does not accelerate the greenhouse effect. At the end of its service life the disposal of modified wood will free no more carbon dioxide than the wood has extracted from the ambient air during its growth.

Environmental balance is so consequently ensured during the entire life cycle of thermally modified wood products.

With one of their recent jobs, Jartek and CAW even took a further significant step towards a total green and CO2-neutral ThermoWood® production. During a mill modernization project, one long-term client with a broad wood products operation decided to decommission their natural gas-fired thermal oil heater / oxidizer and to replace this with a system that will no longer generate emissions from the combustion of fossil fuels. This very client operates a wood wastefired power station and generates all their required energy by utilizing their mill waste.

Jartek awarded CAW with the job to design and install the first of its kind pure electric incinerator for the thermal oxidization of the kiln exhaust. This pioneering system, featuring electric flameless "flox" combustion, does not consume any fossil fuels but operates solely on "green accredited" electricity generated by renewable energy. The installation and commissioning of the system went flawless and the system has been up and running for almost two years now.

Electric flameless flox incinerator installed in Finland.jpg

Meet Jartek and CAW at this year’s LesDrevMash (Лесдревмаш) exhibition in Moscow from 22nd through 25th October. You are cordially invited to drop by to discuss your projects and specific needs around thermal modification of wood as well as process heating and combustion.