Rotary Vacuum Paddle
Dryer (RVPD)

Many powdered solid products require dehydration and solvent recovery from wet cake and slurries.

ACME Rotary Vacuum Paddle Dryers (RVPD) are a perfect solution to overcome these issues. These RVPDs are specially designed to dry products that are temperature sensitive, are susceptible to oxidation, volatile, and those that are toxic in nature ACME RVPDs are great substitutes to other types of dryers that cause air-contamination. ACME provides turnkey solutions covering design to fabrication, installation and commissioning of the entire RVPD plant.

ACME’s RVPD is the most versatile dryer which can handle the products having lumping properties. The integrated drying, mixing and breaking process in single unit under vacuum provides enhanced drying efficiency with low LOD values at low working temperatures, and process economy due to high solvent recovery. It can be used for low temperature drying, extraction of useful solvents, reaction, crystallization, and recovery of solvent.

CONSTRUCTION & OPERATIONS

RVPD consists of jacketed shell with a central agitator shaft having paddle/blades which rotates at a very low RPM. The low clearance agitator paddles/blades scrape the material against the internal heated surface of shell, which provides maximum heating consistently. For uniform drying of product, heat transfer fluids such as hot water or steam is circulated through the shell jacket. This completely jacketed system provides optimum dryer efficiency.

The material which is to be dried is charged as a batch from the top of the shell. As the paddle agitator rotates the product is heated by means of heating media circulated in jacket from the outside and also through the hollow agitator from the inside which increases drying surface and the rate of energy transfer. The paddle agitator is designed to facilitate heating, mixing, drying and discharging of the product, all-in-one. The drying process is carried out under vacuum. The vacuum inside the chamber decreases the pressure around the wet material to lower the vapor pressure of water or solvent thereby reducing the product water or solvent boiling point. Due to this the water or solvent evaporates faster, and enhances the rate of drying. The evaporated solvent pass through the pulsating dust filter before going into the condenser to prevent any solid escaping from the system.

The shell of the dust filter is also provided with the jacket/limpet coil for heating, to eliminate the condensation of solvent vapours in the dust filter chamber. The vapour then condensed, and the condensate is collected in the receiver tank. The automated or manual release of the discharge valve conveniently discharges maximum product, and eases the handling of product without any loss.

FEATURES

cGMP-compliant equipment design & construction
Short drying time
Efficient design of paddle agitator
Gives uniform size and homogeneous dried product
Eliminates product handling and product exposure which ensures maximum operator & environmental safety
Uniform contact between the material, and combined heat from the surface of the dryer and paddle agitator shaft
Dried product contains very low final moisture content
Ease of internal cleaning, operation, inspection and validation which eliminates the chances of product contamination
High vacuum augments the integrated heated system to enable low temperature drying
Operating cost reduction due to low energy consumption
High heat transfer efficiency
Maximum solvent recovery
Eliminates degradation of product since there isn’t over-exposure, higher temperature and drying time
Pulsating filter facilitates dust free operation

OPTIONAL ACCESSORIES

ACME also supplies all the necessary units required for the entire dryer plant suitable for the given batch size

Suitable variable speed-drive and gear-box, to control agitator rotation
Agitator sealing with either stuffing box or mechanical seal with thermosiphon arrangement
Lump breakers
Suitable condenser and receiver for solvent recovery
Advanced PLC control with HMI touch screen to ensure reproducibility of various batches
Hot water system
High Vacuum-pump unit with FLP motor
Safety and instrumentation controls consisting of Temperature controls, Process controls, Overload Protection, Emergency stop, and Vacuum Relief valves as per request
Staircase and gantry for operator
Pulse-jet type dust-filter, to be installed on the shell
High heat transferaFLP motors and electricals efficiency
Dish-end design can also be manufactured and supplied as per requirement
RVPDs are available in various SS grades 304, 316 and 316L. ACME can supply it in different high quality MOCs such as Alloy 20, Alloy 22 and Alloy C276 (Hastelloy C)