Abstract: A heat storage tank is provided to receive a spent liquid from a heat transfer mechanism, to reconstitute the liquid and to return the reconstituted liquid to the heat transfer mechanism for another heat transfer cycle. The tank is divided into at least two compartments. Spent liquid is discharged into a first compartment near its lower portion. Means are provided for passing liquid from the first compartment to a second compartment by drawing liquid from the upper portion of the first compartment and discharging it near the lower portion of the second compartment. The liquid is then drawn from the upper portion of the second compartment and returned to the heat transfer mechanism.

Abstract: A heat transfer fluid storage device is provided, including a tank and one or more vertical chambers open at top and bottom and spaced from the top and bottom of the tank to define upper and lower liquid storage areas. Means are provided to extract liquid from either the lower storage area or the upper storage area, or both, deliver the liquid to heat exchanger means and then return the liquid to either the lower or the upper storage area, or both.