1. What is the evaporation rate and yield of the sodium acetate hydrate CHCOONa 3H30 from a continuous evaporative crystalliser operating at 1 kN/m2 when it is fed with 1 kg/s of a 50 per cent by mass aqueous solution of sodium acetate hydrate at 350 K? The boiling point elevation of the solution is 10 degrees K and the heat of crystallisation is 150 kJ/kg. The mean heat capacity of the solution is 3.5 kJ/kgK and, at 1 kN/m", water boils at 280 K at which temperature the latent heat of vaporisation is 2.482 MJ/kg. Over the range 270-303 K, the solubility of sodium acetate hydrate in water s at T(K) is given approximately by: $ 0.61T - 132.4 kg/100 kg water Molecular masses: CH,COONa. 3H20 - 136 kg/kmol, CH,COONa = 82 kg/kmol 2. A saturated solution containing 1500 kg of potassium chloride at 360 K is cooled in an open tank to 290 K. If the density of the solution is 1200 kg/m3, the solubility of potassium chloride/ 100 parts of water by mass is 53.55 at 360 K and 34.5 at 290 K. 2.1 Calculate the capacity of the tank required. Page 1 of 2 MSOCHA Multistage Operations 3A BET 2.2 Calculate the mass of crystals obtained, neglecting any loss of water by evaporation 3. Glauber's salt, Na:S04.10H:0, is to be produced in a Swenson-Walker crystalliser by cooling to 290 K a solution of anhydrous Na2SO which saturates between 300 K and 290 K. If cooling water enters and leaves the unit at 280 K and 290 K respectively and evaporation is negligible. how many sections of crystalliser, each 3 m long, will be required to process 0.25 kg's of the product? The solubilities of anhydrous Na:SO in water are 40 and 14 kg/100 kg water at 300 K and 290 K respectively, the mean heat capacity of the liquor is 3.8 kl/kg K and the heat of crystallisation is 230 kJ/kg. For the crystalliser, the available heat transfer area is 3 mm length, the overall coefficient of heat transfer is 0.15 kW/m2K and the molecular masses are Na:SO. 10H30 - 322 kg/kmol and Na:SO4 = 142 kg/kmol