In 2015 the company Wirth Tischlerei und Innenausbau GmbH constructed a new building at its old location in Alt-Reutershagen, Rostock, in order to be able to offer the necessary space for the steady growth of the last years. The old workshop at the same location will continue to be used as a wood storage and distributing warehouse.
The company, founded in October 1993, is specialized in high-quality furniture and interior design with built-in furniture and object furnishing, ceiling lining and wall cladding as well as individual solutions for the private sector. With the team of 25 employees, the company can execute complex orders not only near Rostock but also in Hamburg and Berlin. The list of references shows the wide range of customers covered by this specialist for interior finishing. During the new building process the company Wirth also invested in a new painting shop (figure 1).
Concerning the new planned paint shop SPÄNEX was contacted as supplier of the existing and proven speed controlled exhaust system and of the automatically fed boiler plant.
Due to the first quality demands on the surface and considering the wide range of parts, an underfloor exhaust system with flash-off zone was recommended and offered for the combined painting and drying room. In addition to the economic aspect, the energy demand, the utilisation of the existing boiler plant and the availability of fuel from residual materials of the production were the reason to offer the fresh air inlet unit with a cross-flow heat exchanger for heat recovery.
The concept convinced the Managing Director and master cabinet-maker, Mr. Olaf Wirth, so that SPÄNEX was ordered to supply and assemble the paint mist exhausting system. With the new paint room in the dimensions of 12 x 6 m, there is now enough space available for optimal varnishing and drying of the entire part spectrum. The coating area is formed by the exhausting pit covered with gratings in the dimensions of about 4 x 4 m with the above-arranged approximately equal-sized fresh air ceiling. The varnisher can move during the spraying process freely around the workpiece, so that the best conditions for the paint job exist (fig. 2).
The lacquered parts are moved to the other half of the room for evaporation and drying. The dissolved solvents are extracted via a front-side arranged duct in the floor area and fed through the cross-flow heat exchanger arranged in the air supply and exhaust unit (fig. 3).
The coating area is formed by the exhausting pit covered with gratings with the above equal-sized fresh air ceiling.
The cross-flow heat exchanger used for heat recovery achieves a recovery value of approx. 60%, i.e., the outside air is preheated from-15 °c to approx. 5 °c, so that the reheater only must provide the remaining temperature difference of 15 °c to achieve an inlet temperature of 20 °c.
This means that the heat exchanger can be used to save approx. 15,000 kwh per year of thermal energy at the actual current operating grade when varnishing. This is particularly important to ensure that the generated chip quantity is sufficient as fuel and that no further chips must be purchased.
After a half-year of operation, the Managing Director and master cabinet-maker summarizes the hitherto experience with the new painting room as follows: "The concept of underfloor exhausting creates optimal conditions for the high-quality surfaces that are expected by our customers now and in the future. The plant was tailored to our needs by Mr. Kalina, the sales representative from the company SPÄNEX, and convinces by the energy-saving operating method, the ease of operation and the low cleaning and maintenance costs. "
SPÄNEX has used LIGNA in Hanover to inform about the extensive range of paint mist extraction systems, which makes it possible to optimally adapt the plant technology to the requirements and wishes of the customers.