The shape(round vs rectangular) and material(prefabricated steel wood) do not affect the drying operation as long as the previous drying rules(air volume, velocity, and paddy depth) are applied correctly.
Figure 2.9 shows two round prefabricated steel bins with blowers and heaters for drying paddy. This type of round bin usually has a floor made of perforated sheet above the air plenum. Below this is a waterproof subflooc that supports the bin walls and perforated sheet. Figure 2.10 shows welded wire mesh used to form bins inside a weatherproof building. In this case, air ducts are arranged to maintain uniform airflow through the paddy and ensure uniform drying. Bins like these may be used for storage after drying.