US Patent 11320189 Quick freeze pallet racks with variable louvered doors

Pallet racking systems are designed to quickly freeze items using thermal transfer by moving air through palletized products. Air is pulled through the palletized product to a negative air plenum behind the pallet rack. Back panels of the pallet racks provide variable-height airflow by use of louvers which are individually pressed open by the palletized product to accommodate differing product heights. The panels allow more efficient system operation with any number of rack positions filled.