A heat exchanger includes an enclosure having a separator disposed therein that divides the heat exchanger into a mixing area and a heat exchange area. The mixing area is configured to receive a hot fume and droplets of a liquid for mixing with each other to form a fume-droplet vapor mixture. The mixture is configured to flow through orifices of the separator into the heat exchange area. A plurality of magazines is disposed within the heat exchange area of the first enclosure. Each magazine defines a cavity. The cavities are disposed in communication with one another. A lower-most magazine is configured to receive a receiver medium that is pumped through the cavity of each successive magazine to an upper-most magazine. The mixture is configured to circulate about the magazines to incrementally heat the receiver medium as the receiver medium is pumped through the cavity of each successive magazine.