Optimization of sludge granulation parameters and dehumidification efficiency research based on orthogonal experiment

Abstract To improve the drying rate of the sludge dehumidification process and explore the influence of different design parameters on the uniformity of the temperature and humidity distribution in sludge, this paper employs the orthogonal experimental method to analyze three factors affecting the sludge drying rate (sludge spacing, sludge thickness, and sludge length) at five levels. A three‐factor, five‐level orthogonal experimental table is constructed, and numerical calculations are performed on the conditions in the orthogonal experimental table. The research results show that the optimized drying rate is 19.4% higher than the initial design. The influence of each factor on the uniformity of temperature and humidity is in the order of sludge spacing > sludge length > sludge thickness. The optimal combination of the three factors for the drying rate is sludge spacing (10 mm), sludge length (60 mm), and sludge thickness (20 mm). The uniformity of the physical field distribution is the main reason for the increased drying rate. Compared with before optimization, the strength of the temperature field is significantly enhanced after 1 h of dehumidification, and the humidity field shows an ideal trend of overall reduction and uniform distribution. Overall, the optimized field environment exhibits more efficient and uniform drying characteristics.