A standard vacuum tray dryer is a rectangular vacuum chamber housing 4–96 heated shelves (steam or hot water, 30–120°C) that support stainless steel trays loaded with wet product. Operating at vacuum levels of −0.85 to −0.98 bar, it evaporates moisture or solvent at temperatures 40–80°C below atmospheric boiling point drying heat-sensitive APIs, granules, and intermediates to LOD <0.5% w/w without thermal degradation across batch sizes of 5–1,000 kg.
Challenges
Uneven Drying Across Shelf Stack
Upper and lower shelves dry at different rates due to vapour flow path differences.
Tray Loading Ergonomics
Heavy loaded trays (10–15 kg each) require manual loading into shelf stack ergonomic risk.
Solvent Recovery Condenser Sizing
Under-sized condenser allows solvent vapour to reach vacuum pump oil contamination.
Extended Drying Cycle Time
Conductive drying through tray base limits heat transfer; cycles of 8–24 hours typical.
Containment for Potent Compound Tray Handling
Open tray loading/unloading exposes operators to HPAPI powder containment critical.
Solutions
- Shelf-to-Shelf Vapour Equalisation Channels: Internal channels equalise vapour partial pressure across all shelf levels.
- Hydraulic Shelf Extractor for Tray Loading: Each shelf extends out on tracks; loaded/unloaded at ergonomic working height.
- Oversized Condenser (1.5× Design Duty) with Solvent Recovery Tank: Full solvent vapour capacity; zero breakthrough to vacuum pump recovery >98%.
- Microwave-Assisted Vacuum Drying Option: MW energy heats product volumetrically reduces cycle time by 40–60%.
- Contained Tray Loading via Glove Port Wall or Isolator Interface: Full containment during tray loading/unloading OEB 4–5 operator protection.
Applications
- Pharmaceutical: API wet cake drying, granule final drying, intermediates, heat-sensitive compound drying under GMP.
- Biotechnology: Enzyme and protein powder drying, lyophilised product pre-drying, biologic intermediate.
- Nutraceuticals: Botanical extract concentrate drying, heat-sensitive supplement drying, vitamin paste drying.
- Chemical: Specialty chemical wet cake drying, catalyst preparation, solvent-wet intermediate drying.
- Cosmetics: Active ingredient concentrate drying, heat-sensitive cosmetic base intermediate preparation.
Models & Capacities
| Type 1A Standard Vacuum Tray Dryer: Models & Capacities (* At jacket surface temperature 50°C) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | Scale | Batch Size [kg] | Shelf Count | Tray Count | Shelf Temp [°C] | Vacuum [bar abs.] | Max Evap. Water* [kg/h] | Max Evap. Ethanol* [kg/h] | Chamber W×D×H [mm] |  |  |
| VTD-2S | Lab | 5–20 | 2 | 4 | 30–120 | 0.02–0.15 | 1 | 3 | 600×500×400 |  |  |
| VTD-4S | Lab/Pilot | 15–50 | 4 | 8 | 30–120 | 0.02–0.15 | 2 | 5 | 800×700×600 |  |  |
| VTD-8S | Pilot | 40–120 | 8 | 16 | 30–120 | 0.02–0.15 | 4 | 10 | 1,000×900×1,000 |  |  |
| VTD-16S | Production | 100–300 | 16 | 32 | 30–120 | 0.02–0.15 | 8 | 20 | 1,400×1,200×1,600 |  |  |
| VTD-24S | Production | 200–500 | 24 | 48 | 30–120 | 0.02–0.15 | 12 | 30 | 1,600×1,400×2,200 |  |  |
| VTD-48S | Production | 400–800 | 48 | 96 | 30–120 | 0.02–0.15 | 24 | 60 | 2,000×1,800×3,200 |  |  |
| VTD-96S | Large Prod | 600–1,000 | 96 | 192 | 30–120 | 0.02–0.15 | 48 | 120 | 2,400×2,200×4,800 |  |  |