TUNNEL DRY OVEN (POSITIVE PLATE DRYING TUNNEL)
Washed, formed positive plates are dried in heated air either in moving chain tunnel ovens with ample inlet and outlet air supply. Drying temperatures usually range from 80 o C to 100 o C.
The quantity of positive plates dried depends almost entirely on the size of dryer unit itself. As a control, drying is completed when the plates contain less than 0.8 % moisture, calculated on the basis of active material weight of the positive plates only. It is convenient to allow the spaced positive plates to dry slowly in air in racks. These plates in rack thereby attain the final moisture of about 2-3 %. The remaining moisture can then be quickly removed in an oven on the requirement.
The quantity of positive plates dried depends almost entirely on the size of dryer unit itself. As a control, drying is completed when the plates contain less than 0.8 % moisture, calculated on the basis of active material weight of the positive plates only. It is convenient to allow the spaced positive plates to dry slowly in air in racks. These plates in rack thereby attain the final moisture of about 2-3 %. The remaining moisture can then be quickly removed in an oven on the requirement.