Keeping the oven clean from residues, remains to be a major concern during a reflow process. ERSA’s proven multistage management system has been completely re-designed to offer new DUAL capability.
The HOTFLOW 3 can now be fitted with a substantially improved process gas cleaning unit. Up to now, the process gas was extracted from the tunnel between the reflow and the cooling zone, subsequently cooled down respectively cleaned and fed back to the system in the cooling zone. The condensate, accrued during the cooling process, was collected in the condensate trap, which had to be cleaned in regular intervals.
This system has now been extended through the supplementation of a further cleaning stage in the heated section. Thereby the process gas is removed through a conduit, at the end of the preheat area and from the peak zone, fed to the cleaning unit and subsequently, after having been cleaned, it is fed back into the tunnel at the beginning of the preheat zone.
This cleaning unit is of two-tiered design. The first tier consists of an easy to replace cartridge, which is filled with a fine-grained granulate cleaning material. When the process gas passes through the granulate material, the impurities (solvents released from the components, the boards, the solder pastes, etc.) are partially broken down, whereby their physiochemical properties are altered in such a way, that a condensation inside the tunnel is prevented. In the second tier the gas is routed through a specially developed heat exchanger. Here the remaining impurities condense out and are removed, and the clean gas is returned to the process. As was the cartridge, the heat exchanger as well is easily removed for cleaning. With this new cleaning stage, a considerable extension of the time between cleaning cycles has been achieved.
Note: This feature can be retrofitted in all models of the HOTFLOW 3/14, 3/20, 2/14 and 2/20 series!