An expression for the energy transferred from air bubbling through the contents of a tank is developed as a function of the fluid depth in the tank, the specific gravity of the tank contents, the vapor pressure of the solution, atmospheric pressure, and the volume of air used. The variation of the energy transfer with height from the bottom of the tank is also developed.
It is shown that a portion of the energy transferred is used up in small-scale turbulence and eddy effects, and the remainder is available for generation of a circulation pattern in the contents of the tank.
The information developed is used to determine the pulp circulation pattern in pachuca tanks of various design. The functions fulfilled by pachuca tanks are discussed, and the considerations affecting a choice of tank described.