An anaerobic biofuel production process is carried out in a 10,000-L stirred tank with a diameter of 2 m. In order to ensure proper mixing, agitation will be provided using a marine propeller at an agitation rate of 100 rpm. Assume the impeller diam- eter is half of the tank diameter. Note: With a marine impeller, when the impeller Reynolds number is greater than 3x103, the power number has a value of 1.0. What is the power of the motor that is required to accomplish this? You can assume the medium has the properties of water.

3 A continuous countercurrent adiabatic rotary drier is being designed for the production of 500 lb/h of a product containing 2% moisture from wet crystal containing 30% moisture, wet basis. The air entering the drier will have a dry-bulb temperature of 230°F and a wet-bulb temperature of 102°F. The air leaving the drier will be at a temperature of 115°F. Because of the small size of the crystals, the highest allowable air velocity is 10 lb dry air/ft2-min of drier cross section. Find: a. Dry air required (lb/min) b. Cross-sectional area of the drier c. Length of drier required if the volumetric coefficient of heat transfer is 25 BTU/ft3-h-°F

5. A steam power plant operates on the cycle below. Complete the table. -2200.0 kJ/kg Ideal Turbine Work Turbine Efficiency Ideal Pump Work Pump Efficiency 0.75 100.0 kJ/kg 0.80 4000.0 kJ/kg 125 kg/s Boiler Heat Transfer Steam Rate Condenser Heat Transfer Cycle Thermal Efficiency Power Rating (kW)

please show how to derive h using nusselt equation and solve for qheatloss

2 A wire of diameter D = 2 mm and uniform temperature T has an electrical resistance of 0.01 N/m and a current flow of 20 A. (a) What is the rate at which heat is dissipated per unit length of wire? What is the heat dissipation per unit volume within the wire? (b) If the wire is not insulated and is in ambient air and large surroundings for which T = Tsur = 20°C, what is the temperature T of the wire? The wire has an emissivity of 0.3, and the coefficient associated with heat transfer by natural convection may be approximated by an expression of the form, h = C[(T-T)/D]¹/4, where C = 1.25 W/m7/4.K5/4 (c) If the wire is coated with plastic insulation of 2-mm thickness and a thermal conductivity of 0.25 W/m.K, what are the inner and outer surface temperatures of the insulation? The insulation has an emissivity of 0.9, and the convection coefficient is given by the expression of part (b). Explore the effect of the insu- lation thickness on the surface temperatures. Note: 1. The metal wire…

Explain the distillation and heat exchanger with diagram

J 5 A still which produces ethanol from corn mash. Edgar wants to condense the ethanol by running it though a copper tube. If the copper tube can transfer 0.6 btu per second and Edgar wants to produce 10 fifths of ethanol per hour, how long should the tube be?

1. If wind speed doubles, the power output of the turbine will increase by a) 8 times b) 4 times c) 2 times d) 6 times 2. The wind speed at which maximum output power is generated by a wind turbine is called as a) Maximum wind speed b) Cut out wind speed c) Rated wind speed d) Cut in wind speed

Adiabatic process takes place so fast that there is no time for heat to be transferred. O True O False

The heat transfer coefficient, h(W/m2-K) is assumed to be dependent on the fluid density p, dynamic fluid viscosity , fluid velocity V, thermal conductivity, k, fluid specific heat, Cp, and characteristic length of heat transfer area, L. Develop an expression that relates the heat transfer coefficient with the other variables.