A computational‐experimental investigation of thermal vapor compressor as an energy saving tool for the crystallization of sugar in a sugar processing plant

Abstract

AbstractEnergy saving in the food industry is of a great deal of importance. Thermal vapor compressors (TVCs) do not have moving parts which offer advantages including simplicity, low construction capital, and low maintenance costs. In this study, a TVC is designed, and simulated to recover waste vapor streams and reuse the recovered streams in the crystallization of sugar. Computational fluid dynamics is employed to simulate the flows. The effect of motive steam pressure on the entrainment ratio and compressor ratio is simulated. Thermodynamics parameters such as static pressure, temperature, velocity, Mach number, and mass ratios of motive steam and suction are assessed. As the flow is of jet flow type, the realizable k‐e turbulent model is used to model the turbulence. The results show that by applying the motive steam at a pressure of 28 bars (boiler outlet), the pressure and temperature of discharge vapor reach the values of 0.65 bar and 511 K, respectively. The average mass ratios of motive and suction flow at the output of the designed TVC diffuser are 0.59 and 0.41, respectively. As the crystallization pressure demand is 0.6 bar, the findings reveal that the discharged vapor from TVC has sufficient enthalpy to be consumed in the crystallization section, hence making the whole process more efficient.Practical applicationEquipping the crystallization section of the sugar factory with a thermal vapor compressor, beside the recovery of low‐pressure vapor with motive steam, can reduce energy consumption and play a key role in decreasing fossil pollution. Computational Fluid Dynamics is a validated tool in the simulation of the food processing phenomenon. In terms of TVC optimization, the results obtained from this research serve to designers and process managers to get a detailed perception of energy reduction scenarios and recovery of low enthalpy streams.