Pilot freeze-dryer
Free-standing unit for efficient lyophilisation of tray goods
Epsilon 2-16D LSCplus
The Epsilon 2-16D LSCplus freeze dryer is a general-purpose, high-performance pilot unit featuring stainless steel shelves with internal heat transfer media channels for heating and cooling, enabling it to meet even the most stringent demands of the pharmaceutical and biotechnology industries. The key features of this unit are its drying options using up to ten shelves with a total area of 1.2 m2 and a shelf spacing of 83 mm.
The Epsilon 2-16D LSCplus is ideal for small-scale production bulk material, in particular for pharmaceutical specimens with low eutectic/collapse temperatures and products containing solvents.
Technical data
| Ice condenser capacity: | 16 kg |
| Ice condenser temperature: | –85 °C |
| Ice condenser volume: | 108 litres |
| Shelf dimensions: | 300 × 400 mm (W × D) |
| Number of shelves: | 10 |
| Shelf area: | 1,2 m2 |
| Shelf spacing: | 83 mm |
| Shelf temperature: | –60 °C to +60 °C |
| Shelf temperature accuracy: | max. ±1 °C |
| Cooling systems: | Independent systems, water cooled |
| Ice condenser cooling system: | 5.5 kW compressors, two-stage |
| Shelf cooling system: | 3.3 kW compressor |
| Unit dimensions: | 2002 × 1562 × 836 mm (H × W × D) |
Solvent-resistant version
Along with freeze-drying of aqueous media, freeze drying of substances containing aggressive solvents is necessary in some areas such as pharmaceutical research. All of the solvents in this connection have freezing points within the technically manageable range, such as DMSO (eutectic point +15 °C), tertiary butanol (+25.5 °C), dioxane (+12 °C) or acetonitrile (–45 °C). Freeze dryers for this application scenario are designed to be chemical resistant, which means they have modified valves and door seals, special vacuum pumps, and modified cooling systems. The particular advantages of lyophilisation compared to liquid removal by evaporation are the better structure of freeze-dried products (powdery or sponge-like, rather than a viscous mass), lower final solvent content and gentler handling.
Inertisation
Drying and ice condenser chambers are inertised by flushing them with an inert gas, such as nitrogen or argon. The air in the chambers at the start of the process, including the oxygen present in the air, is displaced by the inflowing inert gas. This method is used in particular for the drying of products containing solvents for which an inert atmosphere is required in the process chamber.
H2O2 disinfection
Sterilisation with vaporised hydrogen peroxide (VHP; H2O2) is an economical and effective alternative to pure manual disinfection using isopropanol or similar substances and steam sterilisation, which is common practice in production processes.
VHP is especially worthwhile in situations where the capital cost of installing steam sterilisation equipment is too high, but the benefits of using a reproducible process are necessary. With the VHP method, the freeze dryer is connected to a suitable VHP generator in a closed loop, usually by means of hoses and quick-release couplings, so that the VHP generator can also be as needed with other equipment.
WTMplus 2.0 – Wireless Temperature Measurement
The WTMplus 2.0 (wireless product temperature measurement system) avoids the disadvantages arising from the use of wired temperature sensors. It is significantly easier to use in practice. There is no need for temperature sensor cables or connectors inside the vacuum chamber. The wireless self-powered sensors are placed manually or automatically when the product vials or dishes are filled and report the corresponding product temperatures to the unit controller during the entire lyophilisation process.
Technical data
| Probe dimensions | Length: 21 mm plus 29 mm flexible antenna Diameter: 2.8 mm |
| Temperature measuring range | –60 °C to +135 °C |
| Measurement accuracy | ±1,0 K |
| Temperature resolution | 0.1 K |
Comparative pressure measurement
In addition to product temperature measurement and pressure rise testing, the simultaneous use of two vacuum sensors with different measuring principles can provide information about the progress of the drying process. The commonly used Pirani gauge indicates higher absolute pressures at the start of the primary drying phase because its operation is dependent on the gas type and large amounts of water vapour are released at the start of the primary drying phase. By contrast, capacitive pressure sensors are independent of the gas type. The approaching end of the primary drying phase, which occurs when there is no longer a significant concentration of water vapour, is indicated by the gradual approach of the two pressure curves to each other during the process.
