Technical evaluation pre-dehydration stage under off-solar duration equipped with thermal backup and cyclic fan operation

This work assesses off-solar duration (OSD) dehydration using three volumetric air flows (VAF) which operate under continued, long and short intermittency cycles. VAF and fan continuity is proportional to total water removed of the product with a maximum capacity of 47.3%. However, it costs higher energy consumption, which only results in maximum effective level of fan by 142.4%. Operating the fan under short intermittency at medium VAF achieves a higher effectivity up to 342.5%. The water diffusion of seaweed is a complex and time-consuming process, making the designed operation favorable to enhance effective energy consumption. Employing thermal backup reaches equilibrium moisture quickly under continuous cycle. However, it has the lowest energy effectiveness (only 6.9%), while setting the target to achieve critical moisture offers higher value at 22.7% using short-intermittency cycle. It shows OSD offers reliable results to reduce the midday cycle duration and ensure minimum losses rather than open dehydration.