a. Two streams of water are mixed to form the feed to a boiler. Process data are as follows: 120 kg/min at 30 °C 175 kg/min at 65 °C 17 bar (absolute) Feed A Feed B Boiler pressure The exiting stream emerges from the boiler through a 6 cm ID pipe. Calculate the required heat input to the boiler in kJ/min if the emerging stream is saturated at the boiler pressure. Neglect the kinetic energy of the liquid inlet streams.

Water is to be cooled from 110°F to 85°F in a packed countercurrent water- cooling tower using entering air at 85°F with a wet bulb temperature of 75°F. The water flow is 2000 lbm/h. ft2 and the air flow is 1400 lbm air/h.ft2. The overall mass-transfer coefficient is KGa = 6.90 lb mol/h.ft3.atm. Calculate the tower height needed if air flow of 1400 lbm air/h.ft2 is used.

1. Consider a 1000 MW power plant located in a rural area with 15 ton/day SO2 emissions from a 100 m high stack. The velocity and temperature of the stack gases lead to an effective stack height of 50 m above the physical stack. Estimate the ground level concentration as a function of distance downwind under the following conditions. The emissions are into a clear daytime atmosphere with wind (at 10 m) of 5 m/s. b. The emissions are into a clear nighttime atmosphere with wind (at 10 m) of 2 m/s. The conditions of a. except there is a strong elevated inversion at an altitude of 200 m. a. С.

The liquid food is flowed through an uninsulated pipe at 90 ° C. The product flow rate is 0.25 kg / s and has a density of 1000 kg / m³, a specific heat of 4 kJ / (kg K), a viscosity of 8 x 10-6 Pa s, and a thermal conductivity of 0.55 W / (m) K). Assume that the change in viscosity is negligible. The internal diameter of the pipe is 25 mm with a thickness of 3 mm made of stainless steel (k = 15 W / [m ° C]). The outside temperature is 15 ° C. If the outer convective heat transfer coefficient is 18 W / (m² K), calculate the heat loss at steady state per meter pipe length.    a. Find the convection coefficient in the pipe = AnswerW / m² ° C.    b. Calculate heat loss per meter pipe length = Answerwatt.

An air pipe carries cool air at an inlet bulk temperature of 15C and a velocity of 12 m/s. The pipe is made of carbon steel of 0.25 m diameter, it is not insulated, and it( the pipe) will be maintained at temperature of 120C in order to raise the flowing air temperature to 45C. Calculate the Reynolds number, the heat transfer coefficient in W/(m^2K) and the lenght of this pipe in meters. Use Table A.4 to read the air properties.