LAWS OF HEAT-TRANSFER IN A BUBBLE LAYER

A theoretical model is developed to calculate heat transfer from surfa ces submerged in a bubble layer. The effect of the main regime and geo metric parameters on heat transfer is analyzed. It is shown that exist ing theoretical formulas do not consider the effect of pressure on hea t transfer. It is concluded that published reports of stabilization of heat-transfer coefficients at high gas-phase velocities can be attrib uted to insufficient purity of the bubbling liquid. Relations are prop osed to determine heat transfer from the walls of the tower, individua l tubes, and vertical and horizontal tube bundles during the bubbling of gas or vapor at high pressure. The limits of applicability of the m odel are established Results of calculations are compared with availab le empirical data (pressure 0.1-3.8 MPa, volumetric gas content 0.01-0 .9, corrected velocity of the gas (vapor) phase 0.23-400 cm/sec, heati ng, cooling) and are shown to agree well with one another.