vacuum rake dryer3

Vacuum Dryer with Jacket Heating and Rake Mixing System

Product Overview

This advanced vacuum drying system combines jacketed heat transfer technology with a rotating rake mechanism to deliver efficient, uniform, and hygienic dehydration of various liquid or semi-solid materials under controlled vacuum conditions. Designed for industrial-scale applications in pharmaceuticals, food processing, chemicals, and fine powders, the unit features a robust stainless steel construction, precise temperature control, and an integrated vacuum filtration interface—ensuring optimal performance, safety, and compliance with international hygiene standards.

Key Features

• Efficient Heat Transfer via Jacket Design – The outer jacket circulates steam, thermal oil, or hot water (0.1–0.3 MPa) to indirectly warm the inner chamber, minimizing energy loss while maximizing thermal efficiency.
• Dynamic Material Mixing with Rotating Rakes – A dual-directional shaft equipped with stainless steel rake teeth continuously pushes, lifts, and breaks up material clumps, enhancing surface renewal and preventing wall adhesion.
• Controlled Vacuum Environment (50–90 kPa) – Enables low-temperature evaporation of moisture without compromising product quality, ideal for thermally sensitive substances like APIs, dairy derivatives, or bioactive compounds.
• Hygienic Construction with SUS304 Components – Inner liner made from corrosion-resistant 06Cr18Ni9 stainless steel ensures no contamination risks; outer jacket constructed from carbon steel provides structural durability and thermal stability.
• Comprehensive Process Monitoring – Integrated temperature and pressure gauges allow real-time process optimization, ensuring consistent results across batches.

Detailed Description

The vacuum tank is engineered as a jacketed shell-and-tube system where heat flows uniformly from the external medium into the inner vessel through conduction. This indirect heating method prevents direct contact between the heating source and the material, preserving integrity and purity—especially critical for sterile or high-value products. The internal rotor assembly, driven by a solid SUS304 shaft, employs a combination of left-handed and right-handed rake teeth arranged at 90-degree intervals to ensure thorough mixing, even when handling viscous or sticky slurries. These rakes not only move material laterally but also induce vertical vibration, effectively dislodging adhered particles and maintaining active heat exchange surfaces throughout the drying cycle. With a dedicated vacuum filtration port connected to a sintered stainless steel filter, this system enables simultaneous dewatering and solid separation—an essential feature for continuous operation in batch processes. Additional access points include a large manhole for maintenance and manual feeding, as well as inlet/outlet connections for both heating fluid and process monitoring instruments.

Application Scenarios

Ideal for industries requiring gentle yet rapid removal of solvents or water from heat-sensitive materials, such as pharmaceutical intermediates, herbal extracts, protein-based solutions, and chemical catalysts. It’s commonly used in laboratories transitioning to pilot-scale production, food ingredient processors seeking improved shelf life, and manufacturers aiming to reduce drying time while improving yield consistency. Its modular design supports easy integration into existing production lines, especially where space constraints or cleanliness protocols demand compact, sealed systems.

User Feedback Highlights

Users consistently praise the system’s reliability during extended runs, noting reduced downtime due to clogging compared to conventional tray dryers. Many highlight the ease of cleaning and inspection thanks to the removable manhole cover and smooth internal surfaces. Operators appreciate the intuitive setup of vacuum and temperature controls, which contribute to reproducible outcomes across multiple batches—a key factor in regulatory compliance environments like ISO 14644 or GMP-certified facilities.

Frequently Asked Questions

1. What types of materials are best suited for this vacuum dryer?

This unit excels with pastes, suspensions, sludges, and wet cakes that would otherwise degrade under atmospheric drying methods. Common examples include pharmaceutical granules, fermentation broths, and concentrated fruit purees.

2. How does it compare to tray or drum dryers in terms of energy consumption?

Due to its vacuum-enhanced evaporation and efficient jacket heating, this system typically uses 20–40% less energy than traditional air-drying technologies, especially when processing materials requiring low-temperature treatment.

3. Is maintenance difficult?

No—thanks to the accessible manhole, removable rake assemblies, and corrosion-resistant materials, routine checks and component replacements can be performed quickly without full disassembly. Regular lubrication of the rotating shaft is recommended every 3–6 months depending on usage intensity.

4. Can it handle explosive or volatile solvents?

Yes, provided proper ventilation and grounding are maintained. Always consult local safety regulations before introducing flammable liquids into the chamber. Some models offer optional explosion-proof motor configurations for enhanced hazard mitigation.