Tray Dryer Working Principle:

• In-tray dryer, hot air is continuously circulated. Forced convection heating takes place to remove moister from the solids placed in trays.
• Simultaneously the moist air is removed partially.
• Wet solid is loaded into the trays. Trays are placed in the chamber.
• Fresh air is introduced through the inlet, which passes through the heaters and gets heated up.
• The hot air is circulated by means of fans at 2 to 5 meters per second.
• Turbulent flow lowers the partial vapor pressure in the atmosphere and also reduces the thickness of the air boundary layer.
• The water is picked up by the air. As the water evaporates from the surface, the water diffuses from the interior of the solids by the capillary action.
• These events occur in a single pass of air. The time of contact is short and the amount of water picked up in a single pass is small.
• Therefore, the discharged air to the tune of 80 to 90 % is circulated back through the fans. Only 10 to 20% of fresh air is introduced.
• Moist air is discharged through the outlet. Thus, constant temperature and uniform airflow over the materials can be maintained for achieving uniform drying.
• In the case of the wet granules as in tablets and capsules drying is continued until the desired moister content is obtained.
• At the end of the drying trays or trucks are pulled out of the chamber and taken to a tray dumping station.

Special Features:

• The main body and door are made in SS 316 with a rigid flange.
• Shelves (hollow type) in SS 316 with baffles
• Trays (without back folding) in SS 316
• Condenser (shell & tube) and Receiver in SS 304 for solvent recovery
• Digital Temperature Indicator (FLP) at H.W. Inlet and Outlet
• Digital Temperature Indicator (FLP) at vacuum line
• Dial type vacuum gauge in the vacuum line
• Dial type Temperature gauge in body
• Glass view provided on door and receiver
• Flow glass provided to monitor condensation between condenser and receiver
• Validation port
• Provision for Nitrogen purging
• Vacuum brake valve provided in the vacuum line
• Construction and finish as per cGMP standard

Additional:

• Condenser and receiver are made in SS 316
• 300 mm wide SS 304 skirting all along the flange
• 50 mm thick glass wool insulation on the vacuum chamber outer surface except for the door. The insulation is enclosed and covered with a removable SS 304 angle frame
• Digital temperature controller with pneumatic operated valve at hot water/steam inlet
• 2 stage water ring type vacuum pumps (partial SS) run by FLP motor
• Hot water system with circulation pump

Applications:

• Chemicals
• Dyestuff
• Pharmaceutical
• Food Products
• Colors
• Nutraceutical

Testing Parameters:

• The vacuum dryer shelves are hydro-tested 5 kg/cm2 assembled condition. The vacuum chamber is tested for leaks under vacuum.

Capacity:

• Standard models range from 3 trays to 96 trays

Models available