Drying Equipment

Vacuum Paddle Dryer

Mechotech designs and manufactures the Vacuum Paddle Dryer as turnkey process equipment for the batch drying of wet solids and pastes under vacuum. A single rotating paddle shaft inside a jacketed horizontal vessel keeps the product moving against the heated wall, and the vapour is drawn to a condenser, as Mechotech’s illustration shows with the vessel, a vacuum line, a condenser and a vacuum pump. Mechotech’s RVPD page compares it with the intermeshing-paddle RVPD, which is aimed at sticky pastes, wet cakes and sludges. The unit is designed around the client’s feed and target dryness, then fabricated, installed and commissioned by Mechotech as a single scope.

The Vacuum Paddle Dryer is built in SS 316L (or a process-appropriate grade) as a horizontal, jacketed vessel with a single internal paddle shaft that rotates at low speed, continuously lifting and turning the wet solid or paste so it repeatedly contacts the heated wall. With the vessel under vacuum, moisture or solvent evaporates at a lower temperature and is drawn to a condenser for recovery. Electropolished product-contact surfaces, a fully enclosed shell and PLC-based control of paddle speed, jacket temperature and vacuum support repeatable batch cycles. Capacity is configured to the customer’s requirement, and the unit is delivered with documentation to support GMP qualification.

Process Flow

Technical Specifications

Equipment Type	Vacuum Paddle Dryer — single-shaft paddle-agitated vacuum dryer
Vessel Shape	Horizontal cylindrical shell, fully jacketed
Construction	SS 316L (or process-appropriate alloy), electropolished product-contact surfaces
Agitator	Single paddle shaft, low-speed rotation
Heating	Jacketed shell, heated by hot water / steam / thermic fluid
Vacuum System	Vacuum pump with external condenser
Feed Type	Wet solid, granular material or paste (consistency confirmed in design)
Operating Mode	Batch
Discharge	Bottom discharge valve, paddle-assisted clearing
Automation	PLC-based control of paddle speed, jacket temperature and vacuum level
Monitoring	Jacket temperature, vacuum level, paddle torque / power draw
Cleaning	CIP-capable, fully enclosed shell
Capacity	Configured to requirement — pilot-scale vessels to larger production units
Utilities	Hot water / steam / thermic fluid for jacket heating, vacuum system utilities, electric power
Compliance	GMP hygienic design; full documentation for qualification

Plant Capacities

Vessel Scale	Typical Use	Agitator Configuration	Operating Mode
Pilot-scale	Process trials, small-batch drying	Single paddle shaft	Batch
Production-scale	Commercial batch manufacturing	Single paddle shaft	Batch
Large production-scale	High-volume batch drying	Single paddle shaft	Batch

Vessel volume and heat-transfer area are sized to the batch size, fill ratio and target drying time; no fixed volumes are quoted on this page.

Manufacturing Process

Charging

The wet solid or paste feed is charged into the horizontal vessel through a top port, sized to the batch volume required for the process.

Vessel Sealing & Vacuum Draw

The vessel is sealed and evacuated to the target vacuum level, lowering the boiling point of residual moisture or solvent for drying at a controlled, reduced temperature.

Paddle Agitation

The single internal paddle shaft rotates at low, controlled speed, continuously lifting and turning the product bed so it repeatedly contacts the jacketed, heated wall.

Jacket Heating

Hot water, steam or thermic fluid circulating through the vessel jacket conducts heat into the agitated product, evaporating moisture progressively through the batch.

Vapour Removal & Condensation

Evaporated moisture or solvent vapour is drawn from the vessel headspace under vacuum to an external condenser, where it is recovered and the vacuum level sustained.

In-Process Monitoring

Jacket temperature, vacuum level and paddle torque/power draw are monitored through the cycle to track drying progress and confirm the drying endpoint.

Discharge

Once dry, the product is discharged through a bottom valve, typically assisted by continued paddle rotation to sweep the vessel clear.

Cleaning & Changeover

The enclosed vessel is cleaned in place between batches, supporting validated changeover on multi-product lines.

Major Plant Equipment

Horizontal jacketed drying vessel (SS 316L, electropolished)
Single paddle agitator shaft
Paddle drive motor, gearbox and mechanical seal
Jacket heating system (hot water / steam / thermic fluid)
Vacuum pump and vacuum receiver
Vapour/solvent recovery condenser
Top charge port
Bottom discharge valve
Instrumentation (vacuum, jacket temperature, paddle torque/speed)
PLC-based control panel

Plant Output

Dried powder or granular solidRecovered process solvent (via condenser)

Applications

Batch drying of pharmaceutical and nutraceutical wet solids
Drying of botanical extract granules and pastes
Food-grade powder and granule batch drying
Chemical intermediate and specialty-powder drying
Solvent-wet solids where solvent is condensed and recovered
Process development and pilot-batch drying trials

Key Features

Single-Shaft Agitation
A single paddle shaft keeps the product moving against the heated wall, with a simpler mechanical design than the intermeshing-paddle RVPD.
Vacuum Drying at Reduced Temperature
Under vacuum, moisture or solvent evaporates at a lower temperature, and the vapour is condensed in an external condenser.
Continuous Product Turnover
Paddle rotation repeatedly brings the product bed to the jacketed wall rather than leaving it static.
Straightforward Batch Cycle
A defined charge, dry and discharge cycle with PLC control of paddle speed, jacket temperature and vacuum.
Enclosed, CIP-Capable Vessel
The sealed vacuum shell and CIP-capable design support clean changeover between products.
SS 316L, Electropolished Construction
Electropolished SS 316L product-contact surfaces support GMP hygienic design for regulated batch manufacturing.

Frequently Asked Questions

Does Mechotech supply the complete Vacuum Paddle Dryer?

Yes. Mechotech is a process equipment manufacturer and supplier, engineering and fabricating the complete Vacuum Paddle Dryer at our Hyderabad facility, installing and commissioning it as a single integrated system, with documentation to support GMP qualification. Final parameters are established during process development and pilot validation.

What capacities are available for the Vacuum Paddle Dryer?

Mechotech builds the Vacuum Paddle Dryer from pilot units for process validation to larger commercial installations. Vessel or unit size, duty and ancillaries are configured to the confirmed throughput or batch size; we recommend a pilot unit to validate parameters before scaling.

Which industries use the Vacuum Paddle Dryer?

The uses listed on this page are given under Applications. The industry, the feed and the target output are confirmed with the client before the equipment is configured.

What is a Vacuum Paddle Dryer used for?

A Vacuum Paddle Dryer batch-dries wet solids, granules and pastes under vacuum, using a single rotating paddle shaft to keep the product moving against a heated jacketed wall.

How is this different from the RVPD (Rotary Vacuum Paddle Dryer)?

The Vacuum Paddle Dryer uses a single paddle shaft, while Mechotech’s RVPD page describes dual intermeshing paddles, optionally hollow and heated, for sticky pastes and wet cakes that need lump-breaking. The feed and the caking tendency decide the choice, ideally on a trial.

Why dry under vacuum rather than at atmospheric pressure?

Vacuum lowers the boiling point of the moisture or solvent in the product, so drying proceeds at a reduced temperature, and where the feed is solvent-wet the vapour can be condensed and recovered rather than vented.

What feed types suit a Vacuum Paddle Dryer?

It is configured for wet solids, granular material and pastes. The consistency and the tendency of the feed to cake are confirmed in design, and a sticky or heavily caking paste may call for the RVPD instead.

What information is needed to specify a Vacuum Paddle Dryer?

To configure the equipment Mechotech needs the wet feed and its moisture or solvent content, consistency and caking tendency, the maximum product temperature, the batch size and fill ratio, the target dryness, whether solvent must be recovered, and the hygiene and documentation requirements. A pilot unit is recommended before scaling.

Which related drying pages does Mechotech list?

See the RVPD Rotary Vacuum Paddle Dryer, VTD Vacuum Tray Dryer, RCVD Rotary Cone Vacuum Dryer, ANFD Agitated Nutsche Filter Dryer, Spray Dryer and FBD Fluidised Bed Dryer. The hub is Drying Equipment Plants.

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Vacuum Paddle Dryer