Question 2 Potassium dichromate (K2Cr2O7) is to be recovered from a 21 wt% aqueous solution in a continuous crystallization operation. The solution is joined by a recycle stream and fed to a vacuum evapora- tor where water is removed and the remaining solution is cooled to 30C, at which temperature the solubility of the salt is 0.20 kg K2Cr2O-/kg H20. The solution and suspended potassium dichromate crystals flow to a centrifuge. The crystals and 5.0% of the solution constitute the solid effluent from the centrifuge, and the remaining solution is recycled to the evaporator. The solid effluent, which contains 90 wt% crystals and 10% entrained solution, is fed to a dryer, where it is contacted with hot air. The remaining water in the effluent is evaporated, leaving pure potassium dichromate crys- tals. The air leaves the dryer at 90C and 1 atm with a dew point of 39.2C. For a production rate of 1000 kg solid K Cr20,/h. calculate the required feed rate (kg/h) of 21% solution, the rate of evapo- ration of water in the evaporator (kg/h), the flow rate (kg/h) of the recycle stream, and the feed rate of air (standard liters/h)