Design and Assessment of Heat Exchanger Parameters for Thermal Efficiency in Fish Smoking Kiln

Abstract

Efficient thermal management in fish smoking kilns is essential for enhancing product qual-
ity, optimizing fuel consumption, and promoting operational sustainability. Conventional
kiln systems frequently suffer from inconsistent heat retention and poor energy utiliza-
tion due to suboptimal heat exchanger configurations. This study evaluates the influence
of three key parameters—blower speed (650, 725, and 800 rpm), number of open pipe
inlets (5, 10, and 15), and insulation material (sawdust, clay, and fiber) on the thermal
performance of a locally fabricated heat exchanger integrated into a fish smoking kiln. A
Response Surface Methodology (RSM)-based central composite design was employed to
structure a 20-run experimental matrix, allowing for systematic interaction analysis be-
tween design variables. Airflow rate measurements were taken at the exhaust outlet of
the heat exchanger to ensure consistent thermal load evaluation. Statistical analysis using
ANOVA revealed significant effects (p < 0.01) of blower speed and insulation type on out-
let air temperature, with the maximum temperature of 96?C achieved at 800 rpm, 15 open
pipes, and fiber insulation. Additionally, airflow rate was strongly influenced by both lin-
ear and quadratic terms of blower speed and pipe configuration, with adjusted R2 = 0.995
and Adequate Precision = 79.48, indicating model robustness. This work distinguishes
itself from previous studies by integrating cost-effective materials, a scalable exchanger
design, and a quantitative optimization framework for kiln retrofitting. Its adaptability to
diverse kiln geometries and biomass fuel types underscores its potential for widespread
application across artisanal and semi-industrial fish processing facilities. These findings
offer a replicable pathway for transitioning traditional fish smoking systems toward higher
thermal efficiency and environmental compliance.