Planex System® (Patent N° US 5,857,264) is a new concept multi product dryer, developed for vacuum drying of wet powders obtained from centrifuge or filter press, and it is based on an innovative philosophy of working, especially suitable for the production of Active Pharmaceutical Ingredients, Fine Chemicals and Intermediates.

Planex System® consists of a fixed cylindrical chamber with an eccentric agitator inside with two independent movements, able to rotate on its own axis and tangentially to the cylindrical chamber as well. The double combined rotation allows an optimal mixing of the product, continuously renewing the surface of the mass exposed to evaporation, covering all the volume of the vessel. In this way the release of solvents vapours is facilitated and drying times are significantly reduced compared to conventional systems.

The peculiar configuration of the agitator, characterized by a diameter much smaller than the one of the drying chamber, and the double rotation not only allow the continuous revolution of the product but also limit the mechanical and thermal stress, preventing local overheating due to friction (friction free system). Contrary to what happens with conventional dryers, the Planex System® working process means the total absence of seizure and any metal – product contamination. This enables to treat even more delicate and thermo sensitive products, as it preserves their purity, avoiding degradation of the dried batch.

It must be emphasized that the mechanical and thermal stress on the product is significantly lower than the one observed in traditional paddle dryers equipped with concentric agitator, with consequent reduction of the electricity consumption 1.

The validity of the project and the thermal analysis are also confirmed by the industrial model installed at the Labochim2 factory (Segrate – Milan), used for drying a thermo sensitive product which polymerizes even at 40 °C.

Furthermore the reduced gap between the agitator profile and the wall of the drying chamber avoids deposition of the product and makes the total unloading operation extremely easy and effective, being also foreseen a specific program automatically managed. From the obtained results it comes out that after discharge the Planex System® has a minimum product residual: on average less than 1%.

For the parts in contact with the product Planex System® is built in stainless steel AISI 316L, but on request it i available in any other weldable metal (for instance ALLOY C-22 and AISI 904L).

The wall of the drying chamber, the back cover, the shaft of the agitator and the front door are heated through diathermic liquid circulation in order to avoid cold areas which could cause solvent condensation or product aggregation.

All the internal surfaces of the drying vessel are mirror polished or electropolished in order to optimise the endurance against corrosion, reduce the adherence and the friction on the product, increasing the flow behaviour of the powders and simplifying the cleaning operations.

The shaft of the agitator is complete with a double mechanical seal system, studied to guarantee the perfect vacuum tightness and the absolute purity of the dried batch, avoiding any risk of contamination of the product. The mechanical seal may be of conventional type with wet flushing or run dry with nitrogen immission.

The ease of the inner cleaning is granted by an efficient C.I.P. system, that allows a complete washing of all the parts in contact with the product, while the big front port makes the inspection simple and practical. Also the SWAB TEST execution is facilitated thanks to the profile of the misaligned agitator and the easy dismantling of its inner parts, unlike in the traditional systems where the paddles can not be disassembled.

The exterior of PLANEX System® can also be easily cleaned as the interior. In fact the sealed external cladding (particle-free configuration cGMP) covers the insulation material, the electric wiring and the hydraulic piping.

Besides there is no support frame in the sterile room, but only the drying chamber flanged to the wall. In this way the external cleaning becomes very easy and effective, avoiding accumulation of the product in recessed areas.

These features, combined with the partitioning solution, allow clean room installation, achieving the pressurization and separation of the sterile room from the machine room.

PLANEX System® presents a high loading flexibility. It is manufactured with total volumes ranging from 300 to 4.400 litres. The loading capacity is function of the treated product and it can vary from 15% to 80% of the vessel volume. Both small and big batches can be treated, covering all the requirements of the chemical and pharmaceutical industries.

Planex System® is absolutely safe for the personnel, the environment and the product, being designed and manufactured in compliance with the ever more severe cGMP and ATEX rules.

At the Italvacuum factory (Borgaro – Turin) a semi-industrial model of the Planex System® is available for pilot trials.

Beside the Planex System®, ITALVACUUM provides also all the necessary fittings that complete the plant and that are suitably sized in order to satisfy every process requirement:

• Heating and cooling group for the system thermoregulation
• Condensation vacuum group with tank for the recovery of extracted solvents
• Safety external filtering unit
• High vacuum group (Saurus939 pump)
• Control panel with PLC for the management of operative parameters of the drying process, provided with software which could be certified according to title CFR 21 – Part 11, and able to ensure reproducibility of the dried batch and connectable to centralized supervision systems

Advantages

• Absolute safety for the personnel, the environment and the product according to cGMP rules
• Perfect homogeneity and uniformity of the dried batch, obtained through the controlled action of the agitator that enables a full revolution of the product, avoiding overheating and degradation
• Mechanical and thermal stresses on the product are significantly lower than those observed in traditional paddle dryers equipped with concentric agitator
• Easy and complete unloading of the product thanks to: a) profile of the eccentric agitator, b) reduced gap between the agitator profile and the wall of the drying chamber, c) specific unloading program managed through PLC
• Reduced drying times thanks to a) Agitator speed which can be pushed to elevated values because of its small diameter, b) Double combined rotation of the inner agitator that increases the product surface submitted to evaporation
• Possibility to adjust the speed of the two independent movements of the agitator in both directions (clockwise / anticlockwise) through frequency converters, in order to adapt it to the characteristics of the product and the process
• Electricity consumption is significantly lower than in traditional dryers
• Extremely high final vacuum values (under 0.01 mbar) and very low final moisture values
• Ease of cleaning: a)Ease of internal washing thanks to an effective C.I.P. system that enables the liquid to circulate in every point of the drying chamber, allowing to reach residual p.p.m. requirements with very few rinsing operations, b) Ease of inspection and access to every point of the drying chamber thanks to the wide opening door, c) Ease of SWAB TEST run thanks to the configuration of the misaligned agitator and the easy dismantling of its parts, d) Ease of external cleaning thanks to the complete outer cladding, the absence of supports to the floor for the drying chamber, the opportunity of clean room installation allowing to separate the machine room from the sterile room (Particle Free configuration)
• FDA validation and approval
• ATEX certification.

For further information please visit the web site: www.planexsystem.it