A conical paddle dryer (CPD) is a vertical batch vacuum dryer equipped with a centrally driven paddle rotor. It is designed for drying, mixing and thermal processing of powders, pastes, granules and filter cakes — especially materials that are heat-sensitive, viscous or fragile. The design ensures efficient heat transfer and gentle product handling under vacuum, pressure or atmospheric conditions.
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BATCH DRYERS
for Powders & Bulk Solids
CPD Vacuum Dryer
Conical Paddle Dryer
The CPD conical paddle dryer is a compact, high-performance batch vacuum dryer for the efficient drying, mixing and thermal processing of powders, granules, pastes and filter cakes.
Its centrally driven vertical paddle rotor ensures excellent heat transfer and short drying times, even for viscous or cohesive products. Designed for operation under vacuum, pressure or atmospheric conditions, the CPD offers flexible, high-efficiency processing in a small footprint.
Key Benefits
- Multi-purpose and multi-processing vertical paddle dryer
- Efficient batch drying from free-flowing powders to heavy pastes and viscous liquids
- Compact design and extremely fast drying
- Full compliance with industry standards including FDA, cGMP, EHEDG
- Automated cleaning with our patented CIP solutions optional
- Sterile processing (SIP) optional
- Available in batch volumes from 5–15,000 L
Principle of Operation
The Conical Paddle Dryer consists of a conical shaped process vessel, equipped with a central paddle rotor. When it rotates, the rotor creates a combination of vertical and axial motion in the vessel. The paddles guide the product gently to the surface of the batch, where it is dispersed and the gravitational pull at the centre of the dryer forces the product back down to create continuous motion throughout the drying cycle, even at low speed.
The thermal energy required for the drying process is transferred to the product via a heated jacket, which can be heated by various media such as steam, hot oil and water. The jacket ensures rapid distribution of heat into the product in combination with efficient mixing.
The vacuum inside the Conical Paddle Dryer allows vapour to be removed at low temperatures, which makes the Conical Paddle Dryer ideal for drying heat-sensitive products. The vapours are removed through a dust filter fitted on top of the vessel. This prevents the dust from entering the vacuum system.
The Conical Paddle Dryer is equipped with a condenser with a solvent recovery tank. This condenser can be installed before or after the vacuum pump, depending on the properties of the solvents.
The moisture content of the product can be controlled by monitoring the weight of the condensate or by using the Hosokawa Sampler to take samples from the product inside the dryer under vacuum.
Process Flexibility
The Conical Paddle Dryer is designed for vacuum drying solid based materials, but can be used in a wide range of other process applications requiring thermal processing or vacuum treatment of solids, including:
- Mixing / Drying under vacuum
- Alkalisation, polymerisation, solid-gas reactions
- Cooling of solids and liquids
- Crystallization
- Sterilisation and pasteurisation
- Thermal processing
- Wet agglomeration and granulation of solids
This combination of several processes in one vessel offers tremendous savings on investment costs, labour, and space.
Models & Capacities
Indicative values; performance depends on product properties and process parameters. Detailed specifications available on request.
| Volume | [L] | 5 | 50 | 500 | 1,000 | 2,000 | 3,000 - 15,000 |
|---|---|---|---|---|---|---|---|
| Vessel diameter | [mm] | 300 | 650 | 1,400 | 1,840 | 2,250 | on request |
| Outlet diameter | [mm] | 80 | 150 | 300 | 350 | 400 | on request |
| Height incl. motor | [mm] | 280 | 713 | 1,178 | 2,657 | 3,125 | on request |
| Typical motor power | [kW] | 0.5 – 1 | 1 – 4 | 4 – 20 | 10 – 40 | 30 – 80 | on request |
Our industrial dryers are engineered and manufactured in compliance with global industry standards such as Stoomwezen, PED, TÜV, Lloyd’s, ASME, Afnor and ISPE. They are available in all grades of stainless steel, Monel, nickel, titanium, Hastelloy, etcetera.
Options & Ancillaries
Enhance your Nauta vacuum dryer with a range of ancillary options to fit your processing requirements. Hosokawa Micron provides customised solutions to maximise performance and productivity. Our experienced engineers support you in selecting the optimal ancillary equipment for your application — ensuring smooth operation and long-term efficiency.
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Laboratory & Pilot Vacuum Dryers
Hosokawa Micron’s laboratory and pilot vacuum dryers are compact systems designed for research, development and process optimisation. Built on mobile stainless-steel skids, each unit includes all necessary ancillaries for independent operation. These multi-purpose dryers are ideally suited for experimental work, scale-up trials and fine-tuning of process parameters. Laboratory models are available in capacities from 5 to 20 litres, while pilot units range from 40 to 120 litres.
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Bespoke Drying Systems
With over 100 years of experience in solids processing, Hosokawa Micron has the in-depth knowledge and engineering expertise to design fully integrated, tailor-made drying systems. We understand that optimal performance depends on the precise interplay between equipment, process steps and control parameters — which is why we carefully configure and align every component to function as part of a seamless, high-performance solution.
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Test Before You Invest
Before investing in new equipment, test your materials under real process conditions at our Test & Process Development Centre in the Netherlands. Our experienced specialists help you determine the most efficient mixing, agglomeration or drying process, from laboratory trials to full-scale production testing.
Whether you want to evaluate a single machine or a complete processing line, we provide tailored testing and process optimisation to ensure reliable scale-up and proven performance. We also have rental equipment available for batch drying.
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Talk to our experts
Let our specialists help you configure the right vacuum dryer for your powders and bulk solids — tailored to your process and optimised for efficiency, safety and product quality.
Applications
The CPD conical paddle dryer is ideal for a wide range of products. Here are a few examples:
FAQ – Conical Paddle Dryer
What is a Conical Paddle Dryer?
How does a Conical Paddle Dryer work?
The conical paddle dryer (CPD) features a vertical rotor with fixed or adjustable paddles that rotate inside a conical vessel. As the paddles move, they gently lift the product along the heated vessel wall and allow it to fall back by gravity, generating axial and radial flow. This ensures continuous mixing and rapid drying at low speeds. Heat is transferred via a jacketed wall, and solvents or moisture are removed under vacuum via a top-mounted dust filter and condenser.
What materials can be processed in a Conical Paddle Dryer?
The conical paddle dryer (CPD) is suitable for a wide range of materials, including heat-sensitive or brittle powders, viscous pastes and slurries, solvent-laden filter cakes and hazardous, toxic or explosive substances. Its gentle mixing action makes it ideal for fragile or cohesive products that require low-shear processing and precise temperature control.
What are the advantages of the Conical Paddle Dryer?
The conical paddle dryer (CPD) offers fast drying, high thermal efficiency and excellent product integrity. It supports multiple process modes (vacuum, pressure, atmospheric) and can perform additional operations like mixing, crystallisation, sterilisation and de-aeration — all in a compact, closed system. Cleaning and validation are simplified through optional CIP/SIP integration, and the system is compliant with international standards including FDA, cGMP and EHEDG.
What capacities and sizes are available?
The conical paddle dryer (CPD) is available in sizes ranging from 5 litres to 15,000 litres. Lab and pilot units (5–120 L) are ideal for development and scale-up trials. Full-scale industrial models are tailored to your application and built according to international standards (e.g. PED, TÜV, ASME). Scale-up is predictable due to the system’s geometrical consistency and process transparency.
Can a Conical Paddle Dryer be used for sterile or hazardous applications?
Yes. The conical paddle dryer (CPD) can be supplied in sterile (SIP-capable) configurations and built with explosion-proof features or inert atmosphere operation where required. Its closed design and integrated filtration system make it suitable for handling toxic, flammable or oxygen-sensitive materials in compliance with safety regulations.
Sustainable process technologies
Hosokawa Micron B.V. is committed to sustainable and responsible process technology. Our ISO 14001 certification covers key environmental aspects such as air, soil, energy, waste, water, noise and hazardous substances. With an EcoVadis Silver Medal, we rank among the top 3% of EcoVadis-rated companies in the special machinery industry.
