Benchmarking of Infrared Emitters for Small-Scale Milk Heating: Performance and Heat Flux Analysis

Abstract

An infrared (IR) based heating system was developed, and the suitability of different IR emitters was explored for small scale milk heating. The heating system was designed specifically to fit the different infrared emitters: Ceramic Full Trough Emitter (CFTE), Halogen Infrared Emitter (HIRE), and Pillared Quartz Emitter (PQE). The interface temperatures, rate of change of temperature, time required for heating, convective heat flux, radiative heat flux, total heat flux, energy consumption, and thermal efficiency during milk heating (10°C to 90°C) were analyzed. Analysis of interface temperatures provided key insights into the temperature gradients responsible for driving heat transfer across different regions of the system. The maximum temperature at the emitter–air interface varied between 733°C and 790°C, while the heating rate ranged from 110°C/min to 340°C/min, showing rapid heat generation. Heat transfer characteristics exhibited high radiative heat flux (26,869–64,243.58 W/m²) compared to convective heat flux (6778–9077 W/m²). These differences highlight the critical role of emitter selection in achieving the optimal balance between radiative and convective heat transfer for specific thermal applications. The time required to attain the target temperature of 90°C spanned from 15.25 to 19.87 min. The results validate the applicability of IR heating technology for small scale milk heating.