Tertiary heat exchanger

A tertiary heat exchanger, comprising:

• a container including inlet and outlet means;
• a first fluid conducted into said container through one of said inlet means;
• first conducting means spirally disposed within said container, and forming a passageway extending from said one inlet means outward to one outlet means, for conducting said first fluid out of said container;
• second conducting means for conducting a second fluid through said container;
• third conducting means for conducting a third fluid through said container;
• at least one of said conducting means having a length which is different from the other conducting means;
• one of said fluids being heated, and a substantial portion of said second and third conducting means is coiled within said first conducting means so that each of said second and third conducting means comprises a layered stack wherein each turn of the respective coil defines one layer, and heat from the heated fluid is imparted to the remaining fluids by conduction when said fluids are caused to flow through their respective conducting means;
• the direction of flow of fluid in said second conducting means is opposite to the direction of flow of fluid in said third conducting means;
• and
• said container further comprises surface means located above and below said second and third conducting means for pressing said second conducting means against said third conducting means throughout their entire lengths to facilitate maximum heat transfer between said conducting means.