Hot Air Circulation Drying Oven 200kg Batch 96 Trays Uniform Temperature

An oven that heats from one side and vents from the other wastes most of its energy. The CT-C-II hot air circulation drying oven recirculates the majority of its hot air inside the chamber, so the same electrical or steam input dries twice the load of a once through oven, and the forced ventilation plus the adjustable air distributor keeps the temperature difference between the top and the bottom of the chamber within plus or minus 2 °C. For a 200 kg batch of granule on 96 trays, that uniformity is the difference between an evenly dried batch and a batch with wet trays at the bottom and over dried trays at the top.

The chamber is built around a trolley and tray system: four dollies carry 96 baking trays into the oven, the door closes, and the fan circulates air across the trays through the distributor before it returns to the heater. Because loading and unloading happen on dollies outside the oven, the hot chamber is open for a few seconds only, which saves energy and protects the operator. The CT-C-II hot air circulation drying oven is the workhorse unit of a solid dosage plant for granule, herb and foodstuff drying where a fluid bed is not suitable.

• 200 kg Per Batch Dry Capacity: the CT-C-II dries 200 kg of wet granule per cycle on 96 trays carried by four dollies, matching the output of two high shear granulator batches per shift.
• Plus Minus 2 °C Uniform Air: forced circulation and an adjustable air distributor hold the top to bottom temperature difference within plus or minus 2 °C, so every tray dries at the same rate.
• Recirculating Hot Air: most of the air returns to the heater instead of being vented, which is why this hot air circulation drying oven consumes far less energy than a once through design.
• 96 Trays on 4 Dollies: trolley loading keeps the chamber open only briefly, reduces heat loss and eliminates manual tray handling inside a hot oven.
• Steam or Electric Heating: the standard unit runs on 0.9 kW of fan power with 40 kg/h of steam, and an electric heater version is available where no steam boiler exists.
• Low Maintenance Construction: stainless steel interior, insulated panel walls, hinged insulated door with a silicone gasket and a simple axial fan arrangement, all serviceable from the front of the oven.

The hot air circulation drying oven is the general purpose drying unit of a pharmaceutical, food or chemical plant, and it is specified when the product cannot be fluidized:

1. Wet granule from a high shear or slot mixer, dried on trays before tableting.
2. Herbal material, sliced root, extract impregnated carrier and traditional medicine intermediate.
3. Foodstuff such as dried fruit, vegetable slice, seasoning and noodle, where shape must be preserved.
4. Chemical and pigment cake, catalyst and ceramic part dried at a controlled temperature.
5. Heat setting and curing of coated or impregnated parts at a steady temperature.

Because the hot air circulation drying oven accepts almost any tray compatible product, it is often the flexible backup unit in a plant that also runs fluid bed dryers: when a fluid bed is occupied by a granulation campaign, sticky or coarse material can still be dried on trays in the same building.

Why is plus or minus 2 °C important? Drying rate roughly doubles for every 10 °C rise, so a 10 °C spread across the chamber would over dry the top trays and leave the bottom trays wet. The adjustable air distributor of this hot air circulation drying oven is set once for the load pattern and then keeps the spread within 2 °C.

How long does 200 kg take to dry? A typical granule load at 15% to 20% initial moisture dries in 4 to 8 hours at 80 to 100 °C. Because the air recirculates, the cycle is shorter than a once through oven at the same set temperature.

Can the oven run on electricity only? Yes. An electric heater bank replaces the steam coil where no boiler is available, and the working temperature then extends to 150 °C. Steam heating is recommended when steam is already on site, because running cost is lower.

How are the trays loaded? Trays are stacked on four dollies outside the oven and rolled in on rails. That keeps the door open for less than a minute, which protects the operators and avoids the temperature drop that manual tray loading causes in a walk in oven.

The hot air circulation drying oven ships as insulated wall panels, fan and heater assembly, door and frame, packed in export plywood cases with the control panel separately protected, and the trays and dollies are strapped as a separate lot if ordered. Temperature uniformity is measured at nine points before dispatch, and the documentation includes heater ratings, fan curve data, insulation specification and electrical drawings. The warranty covers 12 months, and fan bearings, door gaskets, heater elements and controller spares are available as a two year kit.