calculate the residence time of the methane stream in the porous absorber given the solar power of 2.3193 kW and a felt temperature of 1758 K. the methane flow rate is 12683.916793505834 cm^3/min. the porous carbon felt absorber has a porosity of 0.9 and a thickness of 3.2 mm.

Number 3 A food product with 73% moisture content in a 5 cm diameter can wants to be frozen. The density of the product is 970 kg / m³, the thermal conductivity is 1.2 W / (m K), and the initial freezing temperature is -1.75 ° C. After 10 hours in the freezing medium -25 ° C, the product temperature becomes -10 ° C. Estimate the convection heat transfer coefficient of the freezing medium. Assume the can as an infinite cylinder. identify: a. h = Answer in W / (m² K).

2. The wall of a furnace is made up of a material which has thermal conductivity of 1.65 W/m•C and a thicknesses 250 mm. The inner side of the furnace wall is exposed to hot gases at 1000 °C with a convection coefficient of 25 W/m2°C and the inside the surface is at 800 °C. The air outside the furnace is at 25°C with a convection coefficient of 12 W/m2°C. a. Draw a clear diagram representing the system b. Determine the temperature of the outside surface of the furnace C. The rate of heat loss from the furnace.

2) Consider two cubes of plastic and wood that are floating in water, each of side s. (see diagram). The density of the plastic is 80.0 % of the density water and the density of the wood is 60.0 % of the density of water. An aluminum block having base area s? is going to be glued on top of the plastic and wood system. The density of aluminum is 2.7 times the density of water. Assume the system stays upright (does not tip over). Alum block a) How tall does the aluminum block need to be if the top of the aluminum block will be at the surface of the water when equilibrium is reached ? Give answer in terms of s. woed water plastic on tup