Plate Freezer

Plate freezers transfer heat by direct conduction between refrigerated metal plates and product surfaces, whereas air blast freezers rely on convection. Because aluminum conducts heat roughly 10,000 times more effectively than air (~200 W/(m·K) vs ~0.02 W/(m·K)), contact plate freezing delivers:

• Freeze cycles 3 to 6× faster than static blast freezing rooms
• Lower compressor energy consumption per ton of frozen product (higher evaporating temperature)
• Zero evaporative dehydration and no surface freezer burn on packaged blocks
• Flat, uniform carton and block geometry that maximizes pallet and cold storage density
• Smallest equipment footprint per ton of daily freezing capacity

Horizontal Plate Freezer: Plates are arranged horizontally. Cartons, trays, or panning frames are loaded from the front/side manually or via automated conveyor, and hydraulic cylinders close the stack vertically. Ideal for boxed meat, poultry, seafood pans, ready meals, and fruit concentrates.

Vertical Plate Freezer: Plates are arranged vertically. Unpackaged whole fish, by products, or slurries are loaded from the top between open plates and frozen into dense, self supporting blocks before hydraulic discharge. Ideal for marine trawlers, bulk Pelagic fish, offal, and pet food ingredients.

A standard hydraulic contact plate freezing cycle proceeds through five controlled stages:

• Loading (5 to 15 min): Cartons, pans, or bulk product are loaded between open freezing plates manually or via automated loader
• Hydraulic Clamping (30 s): Hydraulic cylinders lower the plate stack to establish uniform double sided surface contact
• Conduction Freezing (90 to 240 min): Liquid refrigerant circulates through internal plate channels until the block core reaches −18°C
• Plate Release (1 to 3 min): For unpackaged vertical blocks, a brief warm gas pulse releases the frozen block surfaces
• Discharge (5 to 15 min): The hydraulic stack opens and flat, uniform frozen blocks are discharged for palletizing

Each extruded plate contains multiple pass internal refrigerant channels connected via stainless steel braided PTFE flexible hoses:

• Balanced liquid distribution headers ensure uniform surface temperatures (±1°C) across every station
• Compatible with pump recirculated NH₃, CO₂, DX HFC, or secondary brine/glycol circuits
• Optional hot gas defrost manifold for rapid release of unpackaged vertical blocks
• Every plate and manifold assembly is factory pressure tested at 1.5× maximum allowable working pressure

Plate freezers have the smallest footprint per ton of freezing capacity. A single 15 station horizontal plate freezer producing 20 tons/day occupies approximately 25 to 35 m². Compare to a blast freezer of equivalent capacity requiring 80 to 120 m² plus air handling equipment. Plate freezers require: level floor (±5 mm), overhead clearance for loading equipment (2 to 3 m above station), and connection to your facility’s refrigeration system.