As the name implies, force is used to drive the liquid through the evaporator tubes thus producing high tube velocities. A high efficiency circulating pump, designed for large volume and sufficient head, is used to supply the force. Proper design results in controlled temperature rise, controlled temperature difference and tube velocities that give optimum heat transfer. This type is recommended for viscous, scaling and salting liquids. As the liquid is only heated
in the steamchest with flashing taking place in the separator and no boiling taking place within the tubes, fouling on hot tube walls is reduced.
BUFLOVAK Forced Circulation Evaporators may be equipped with either horizontal or vertical steamchests. The circulating pump withdraws liquid from the lower part of the vapor-liquid separator and circulates it through the tubes at a high velocity. Boiling is suppressed in the tubes either by liquid head or an orifice plate. The heated liquid is discharged into the separator where the vapor flashes off due to the temperature difference and is removed through the top outlet. The liquid is discharged at a maintained liquid level.