Induced temperature gradient settling vessel

a method for settling solids particles of micron and submicron size from a liquid in which the particles are contained, said method comprising:

• a. admitting said liquid containing solids particles through an inlet into the lower portions of a settling vessel having vertical dimensions sufficient in reltion to the overall capacity of the vessel to allow a temperature gradient between the upper and lower portions of the liquid contained therein and sufficiently insulated to minimize changes of temperature inside the vessel in response to changes in ambient temperature outside the vessel;
• b. cooling the liquid by indirect contact with a cooling fluid in the lower portion of said vessel;
• c. allowing said liquid to pass upward into contact with means in the upper portion of said vessel for heating said liquid;
• d. heating said liquid by indirect contact with a heating fluid;
• e. retaining said liquid within the vessel for a time sufficient to allow settling of said solids particles at least from the liquid contained in the upper portions of said vessel;
• f. removing clarified liquid through an outlet from the upper portions of said vessel;
• and
• g. removing said settled solids particles from the lower portion of said vessel.