The use of water-based paints instead of paints with volatile organic compound bases has led to a new problem: the need for the absorption of excess water from the paint in a relatively short space of time, in order to achieve a high-quality first coat of paint. After this operation, the final lacquer coating can be applied.
An “intermediate oven”, where the drying takes place, is set up for this installation in a paint tunnel.
The normal requirements for this area are 22ºC and 20%RH (3.2 g/kg at sea level). The dry air flow is determined according to the painting process, the quantity of paint applied and the time elapsed in the oven.
The dehumidifier only dries exterior air (between 15 and 20% of the total flow), which is subsequently mixed with the return air.
In some cases, FISAIR dehumidifiers also provide the heat required by the tunnel, and therefore, heat the air to 65ºC, while mixing with the return air to keep the paint tunnel at 26ºC.
A tunnel with lesser requirements (22ºC and 65%RH) is shown below with a subsequent air treatment unit to mix and cool. FISAIR can also manufacture the ensemble to include these units as well, but sometimes, because of their easy-assembly and transport, it is best just to send the dryer.
Some examples of this application are given below:
- 3 DFRM-2900-AS-E-BF1-BF2-BC2 units, from 2004 to 2006. Seat Volkswagen. Painting lines I, II; and III. Martorell, Barcelona, Spain.
- 2 DFRA-2100-G-BF1 units, 2006. RENAULT, Lines A and B. Valladolid, Spain.
In both cases, FISAIR was first approved as a supplier of Seat and Renault. And also for the Renault Technological Centre in Paris.
- 2 DFRA-2100-G units, 2007. DACIA-Renault in Rumania.