Problem 7 Steam enters an adiabatic diffuser at 200 kPa and 150°C with a velocity of 600 m/s. Determine the minimum velocity that the steam can have at the outlet when the outlet pressure is 400 kPa. Problem 8 A 0.6-ft³ well-insulated rigid can initially contains refrigerant-134a at 100 psia and 20°F. Now a crack develops in the can, and the refrigerant starts to leak out slowly. Assuming the refrigerant remaining in the can has undergone a reversible, adiabatic process, determine the final mass in the can when the pressure drops to 15 psia.

You serve as the president of XYZ corporation, which is an energy intensive manufacturing operation. You have four boilers to produce steam and electricity for your operations. One is a semi-suspension fired boiler with a capacity of 100 tons of coal per hour. The boiler can also burn supplemental fuel such as coconut or macadamia nut shells. The other three boilers arc peaking units and burn fuel oil. The City of Podunk has approached you about the possibility of burning solid waste as a supplemental fuel. As the president of the XYZ Corporation, you need to develop answers to many political, social, and technical questions before you make a commitment to the city. a. What specific questions would you ask your own power plant engineer about the possibility of accepting Podunk’s MSW? b. What specific additional data would you need from the city before you discuss this further?

Calculate the thermal resistance due to convection for the following situations: a. warm water with h = 200 W/m2 K b. warm air with h = 10 W/m2 K c. warm moving air (windy situation) h = 30 W/m2 K

Two materials, A and B, are to be separated using two unit operations, 1 and 2. The feed has 10 tons/h A and 4 tons/h B. The split (fraction of material rejected by each operation) is given in Table P5-14. a. Which sequence of operations, (l?2) or (2?1), will yield the greatest recovery of material A? b. What will be the purity of material A using that sequence? c. What will be the efficiency of separation for the entire process train with regard to material A using the Worrell-Stesed equation?