Double Cone Rotary Vacuum Dryer 500L Working Volume 6rpm Low Temperature

Many powders cannot survive the air temperature of a hot air dryer. The SZG-1000 double cone rotary vacuum dryer removes that constraint by drying at low temperature under vacuum: the jacketed twin cone rotates at 6 rpm while the vessel is held between -0.1 and 0.15 MPa, so moisture leaves the product at 40 to 60 °C and the material never meets an oxidizing air stream. Vitamin premix, enzyme granule, thermo labile pigment and crystalline product all keep their colour, activity and crystal structure.

Rotation is the second function of the double cone rotary vacuum dryer. As the cone turns, the powder bed slides and cascades inside the vessel, so drying and blending happen in the same operation and the batch leaves the dryer already homogeneous, with no separate blending step and no transfer loss. A 500 L working volume inside a 1000 L total volume accepts a 250 to 500 kg batch depending on bulk density, and the 4.61 m² jacket heating area keeps the drying cycle within 3 to 8 hours for most products.

• Low Temperature Drying: vacuum lowers the boiling point of water, so the double cone rotary vacuum dryer finishes the batch at 40 to 60 °C and protects heat sensitive actives from degradation.
• Oxidation Free Operation: the sealed vessel is evacuated before heating, so oxygen sensitive powders keep their colour, aroma and potency without a nitrogen blanket.
• Drying and Blending in One Vessel: the 6 rpm tumbling action homogenizes the bed while it dries, which removes a separate blending step and the associated transfer loss.
• Full Jacket Heating Area: 4.61 m² of jacketed surface transfers heat through the cone wall, and the jacket handles steam, hot water or cooling brine at up to 0.3 MPa design pressure.
• Solvent Recovery Ready: the vapour outlet can be piped to a condenser and receiver, so residual solvent is recovered instead of vented, which matters for ethanol and  wetted products.
• Crystal Structure Preserved: because there is no impeller and no air stream, crystalline and needle shaped materials are not broken or attrited during drying, and the finished powder keeps its original particle shape.

The double cone rotary vacuum dryer is specified wherever heat, oxygen or mechanical attrition would damage the product:

1. Pharmaceutical and nutraceutical powders with thermolabile actives, vitamins and probiotics.
2. Chemical intermediates that oxidize in air or discolour above 70 °C.
3. Crystalline and needle shaped products where particle breakage is unacceptable.
4. Solvent wetted material requiring recovery of ethanol,  methanol from the vapour stream.
5. Food and feed premix, enzyme granule and flavour powder needing gentle low temperature drying.

Because the vessel is closed during the whole cycle, the double cone rotary vacuum dryer also suits toxic or strongly irritating powders: loading and discharge are carried out through a sealed butterfly valve, and the operator is never exposed to an open product bed.

How low a temperature can the double cone rotary vacuum dryer run at? At a working vacuum of -0.08 to -0.1 MPa water boils near 45 to 60 °C, so a jacket temperature of 60 to 90 °C is enough to finish most batches while the product itself stays below 60 °C.

Does the 1000 L unit really dry and blend at the same time? Yes. The 6 rpm rotation cascades the bed along the cone wall, so the material is continuously renewed against the heated surface. That is why the double cone rotary vacuum dryer needs no separate blender afterwards.

Can solvent be recovered? The vapour outlet is flanged for a condenser, a receiver and a vacuum pump set. Ethanol and  wetted products are routinely dried with 85% to 95% solvent recovery when the condenser is sized correctly.

How long is a typical drying cycle? For a 500 L working volume batch with 15% initial moisture, the double cone rotary vacuum dryer normally completes drying in 3 to 8 hours, depending on bulk density, jacket temperature and the vacuum level held by the pump.

The double cone rotary vacuum dryer ships as one assembly with the drive frame skidded and braced inside an export plywood case, and the jacket and vessel are pressure tested and certified before dispatch. Documentation includes material certificates, a pressure test report, a vacuum leak test record and an internal surface roughness report. The warranty runs 12 months, and we supply mechanical seal sets, butterfly valve seals, vacuum pump spares and a preventive maintenance schedule for the full service life of the unit.