Apple juice is being concentrated in a natural circulation single effect evaporator. At steady state conditions, dilute juice is the feed introduced at a rate of 7 kg/s. The concentration of the dilute juice is 10% total solids. The juice is concentrated to 50% total solids. Steam is available at 205 kPa and evaporation takes place at 13.5 kPa. The specific heat of dilute apple juice is 3.76 kJ/kg. The inlet feed temperature is 21oC and the condensate leaves the heating space at 79.7oC . The overall heat transfer coefficient is assumed to be 3000 W/m2K. Assume negligible boiling point elevation. Calculate: a) mass flow rate of concentrated product b) steam requirements c) steam economy

A stream of ammonia is cooled from 100oC to 20oC at a rate of 180 kg/hr in the tube side of a double-pipe counter-flow heat exchanger. Water enters the heat exchanger at 10oC at a rate of 250 kg/hr. The outside diameter of the inner tube is 3 cm and the length of the pipe is 7m. Using the log-mean temperature difference, calculate the overall heat transfer coefficient (U) for the heat exchanger. Determine the heat transfer rate between the two fluids. Determine the outlet temperature of the water. Determine the heat transfer surface area. Determine the log-mean temperature difference. Determine the heat transfer coefficient for the heat exchanger.   Cp for ammonia is 5234J/kgK and cp for water is 4180J/kgK.

Heat Transfer Question

9. SOC high crude oil is to be heated from 15° C to 55° C at the rate of 1,50 ton/h using a stream from the plant. The crude oil is pumped in to the tube and the heating stream is pumped into the shell side of an available heat exchanger. The heating stream enters in to the tube at 150° C and leaves the tube at 110° C. The average properties of both the fluids are given below. The available heat exchanger (1-2 pass) has shell diameter of 23% in. The shell has 324 tubes, ¾ in. OD, BWG 14 (wall thickness), 12 feet long arranged on 1 in. Square pitch and supported by baffles with a 25% cut, spaced at 9 in interval. You need to find the suitability of this exchanger for the purpose. What will be the allowable fouling factor? Heating stream Crude oil cp, J/g. ° C 2.2 2 H, CP 5.2 2.9 P, kg/m3 k, W/m. C 866 822 0.12 0.138