Abstract: A wastewater treatment device evaporates water from contaminant containing wastewater, to produce a contaminant concentrated residue. The device includes a transport, such as pump, for transporting wastewater to a wastewater applicator, and a wastewater applicator for applying the wastewater to an evaporating surface of an evaporator drum. A rotatable evaporator drum has a heat conductive evaporating surface, and a heater for heating the evaporating surface to foster the evaporation of water from the wastewater. A motor, chain and drive shaft are provided for rotating the evaporator drum, and a scraper is provided for removing the contaminant concentrated residue from the evaporating surface. A controller is provided for controlling the operation of the device.

Abstract: A soldering technique is provided especially for printed circuit boards wherein a bath of solder assisting fluid such as non-ionic surface active agent is superposed on a bath of solder. In one form, the workpiece is passed through the bath of solder assisting fluid and solder is pumped from the bath of solder to a trough whereat the solder is cascaded onto the workpiece. In another form, the workpiece is passed downwardly through the bath of solder assisting fluid into the bath of solder for the application of solder to the workpiece. Thereafter, the workpiece is withdrawn from the bath of solder through the bath of solder assisting fluid. In both instances, while the workpiece is still within the bath of solder assisting fluid, jets of this fluid are played against the workpiece to control the thickness of the solder which is allowed to remain on the workpiece.