Arapid-mixing basin is to be designed for a water coagulation plant, and the design flow for the basin is 15,140m3/d. the basin is to be square with a depth equal to 1.25 times the width. the velocity gradient is to be 900 s-1 (at 10 °c), and the detention time is 30s. determine: a) the basin dimensions. b) the input power required. c) the impeller speed if a vane-disc impeller with six flat blades is employed and the tank is baffled. the impeller is to be 50% of the basin width.

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody

Acertain flow of air (at stp) has a velocity distribution given by v i (in ft/s). if this flow is going through a 4 ft square area in the yz-plane (centered at the origin), what is the mass flow rate (in lbm/s)?

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.