An evaporator is used to concentrate 4536 kg/hr (10,000 lb/h) of a 20% solution of NaOH in water entering at 600C (1400F) to a product of 50% solids. The pressure of the saturated steam used is 172.3 kPa (25 psia) and the pressure of the vapor phase in the evaporator is 11.7 kPa (1.7 psia). The overall heat transfer coefficient is 1560 W/m2-K (275 BTU/h-ft2 – 0F). Calculate for the steam used, steam economy, and heating surface area. 4. From the enthalpy-concentration chart of NaOH in the Handbook the enthalpy of the feed is _____________ and the enthalpy of the liquid product is _______________. 5. From steam tables the latent heat of condensation of the condensing saturated steam is ______________. 6. From steam tables the enthalpy of the vapor product is ________________.
An evaporator is used to concentrate 4536 kg/hr (10,000 lb/h) of a 20% solution of NaOH in water entering at 600C (1400F) to a product of 50% solids. The pressure of the saturated steam used is 172.3 kPa (25 psia) and the pressure of the vapor phase in the evaporator is 11.7 kPa (1.7 psia). The overall heat transfer coefficient is 1560 W/m2-K (275 BTU/h-ft2 – 0F). Calculate for the steam used, steam economy, and heating surface area.
4. From the enthalpy-concentration chart of NaOH in the Handbook the enthalpy of the feed is _____________ and the enthalpy of the liquid product is _______________.
5. From steam tables the latent heat of condensation of the condensing saturated steam is ______________.
6. From steam tables the enthalpy of the vapor product is ________________.
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