Design and fabrication of a regenerator chamber for a continuous pasteurizer

Abstract

The agro-processing industry has developed to increase production, boost product value addition, and preserve food. This has not been achievable due to dependence on imported machinery and the high cost of production in processing. Efforts to develop locally fabricated machines are still impugned by energy inefficiency that results in the high costs of production, especially thermal food processing machines leading to technologies not being adopted. ABE with support from FBTIC is developing a continuous pasteurizer that is energy efficient. This study aimed at the design and fabrication of the regeneration unit of the continuous pasteurizer. A proper simulation was done using Computational Fluid Dynamics (CFD) to establish the best cross-section for tubes. The machine components were properly sized to the appropriate heating area. The machine was fabricated using stainless steel 316. The regenerator was tested to establish its performance indices. The performance tests focused on the effect of tube side flow rate and shell inlet temperature on the tube outlet temperature and thermal effectiveness. The regenerator was found to have thermal effectiveness of 78.24%. The tube flow rate, shell inlet temperature and its interaction effect significantly (p < 0.05) affected the tube outlet temperature. In conclusion, the machine elevates the temperature of the cold fluid by 30 °C, efficiently reducing the energy budget expense on heat by 40 %. It is recommended that the machine is further tested at varying shell mass flow rate to ascertain optimum flow rates. Also, future machines should have the tube inlet and outlet openings located at topmost end to of the shell to enable tube filling.