Heat Transfer to Falling-Water Films

Data are presented in this paper for heating water as it flows by gravity in turbulent motion down the inner walls of vertical copper pipes, ranging in height from 0.41 to 6.1 ft. Heat balances check within 5 per cent and the temperature of the inlet water ranges from 38 to 146 F. The data are adequately correlated by the equation: h = 120Γ^1/3, where Γ ranges from 600 to 15,000 lb of water per hr per ft of width of stream. Steam-side and over-all coefficients are given. The rather inadequate data for streamline flow by gravity over nearly horizontal pipes (trombones) are reviewed.