A stainless steel Soxhlet extractor combines the classical Soxhlet extraction principle with modern industrial engineering. For manufacturers of botanical extracts, traditional medicines, nutraceuticals, food ingredients and fine chemicals, it offers a powerful solution for solid–liquid extraction, vacuum concentration and solvent recovery in one compact system.
Nanjing Hjchem Equipment Co.,Ltd has developed a fully integrated stainless steel Soxhlet extractor that unites:
Soxhlet extraction
Multi-functional (dynamic circulation) extraction
Vacuum concentration
Solvent recovery
in a single unit. Each subsystem can be linked together for combined operation or run independently as a stand-alone system, giving you exceptional flexibility from lab and pilot trials up to industrial production.
What Is a Stainless Steel Soxhlet Extractor?
A traditional Soxhlet extractor is a glass apparatus used in laboratories to repeatedly wash a solid sample with hot condensed solvent. A stainless steel Soxhlet extractor from Nanjing Hjchem translates this concept into a sanitary, corrosion-resistant industrial machine designed for kilogram to ton-scale batches.
In our design, the stainless steel Soxhlet extractor is much more than a single vessel. It is a modular, process-integrated system that typically includes:
Extraction tank – for initial solvent boiling, pre-extraction and mixing
Soxhlet extraction tank – where repeated hot solvent percolation over the solids takes place
Vacuum concentration / solvent recovery tank – for concentrating the extract and recycling solvent
Dynamic circulation extraction loop – for multi-functional, forced-circulation extraction modes
Vacuum system – typically a water-ring vacuum pump for reduced-pressure operation
Explosion-proof electrical components and explosion-proof HMI touch-screen control cabinet – for safe, automated operation with flammable solvents
Because all major components are made in stainless steel (SS304 or SS316L depending on process needs), the system is suitable for food, pharmaceutical and cosmetic applications, as well as high-value fine chemicals.
Stainless-steel Soxhlet Extractor Structure
Soxhlet Extraction, Dynamic Extraction, Concentration & Recovery in One Skid
Unlike simple extraction vessels, our stainless steel Soxhlet extractor is an integrated process platform. The key subsystems are:
1. Soxhlet Extraction System
The Soxhlet module is designed to:
Repeatedly wash the solid bed with fresh, hot condensed solvent
Use a siphon mechanism to return extract-rich solvent to the boiling / recovery tank
Achieve thorough extraction of target components with efficient solvent usage
This is ideal when you want the classical advantages of Soxhlet extraction—high yield, strong enrichment and predictable performance—at industrial scale.
2. Dynamic Circulation Extraction System
In addition to classical Soxhlet operation, the unit incorporates a dynamic circulation extraction system:
Solvent is circulated through the extraction tank and the material bed using pumps and piping
Continuous or semi-continuous flow improves mass transfer and extraction speed
Process parameters (flow rate, temperature, time) can be adjusted to match different botanical or chemical materials
Because the Soxhlet extraction system and dynamic circulation extraction system can be flexibly combined or run separately, you can choose the most suitable mode for each product:
Soxhlet mode for deep, repeated washing
Dynamic circulation mode for faster extractions
Hybrid operation when needed
3. Vacuum Concentration & Solvent Recovery System
The integrated vacuum concentration and solvent recovery system is another key advantage:
After extraction, extract-rich solvent is transferred to a vacuum concentration tank
Under reduced pressure, the solvent boils at a lower temperature, protecting heat-sensitive components
Concentrated extract is collected, while solvent vapors are condensed and returned for reuse
This configuration:
Reduces solvent consumption and operating cost
Improves environmental performance due to less solvent loss
Simplifies plant layout compared with separate, stand-alone concentrators
4. Flexible, Modular Operation
One of the most important process benefits is flexibility:
The Soxhlet extraction system, dynamic circulation extraction system and vacuum concentration system can be:
Combined and linked to run as one integrated process line, or
Operated individually as independent systems
This modular concept allows you to:
Start with simple extraction only, then add concentration and solvent recovery later
Use the same skid for different products with different process flows
Optimize each step (extraction, concentration, recovery) without buying separate equipment for each function
Design Features of Nanjing Hjchem Stainless Steel Soxhlet Extractor
1. Stainless Steel Construction
Product-contact parts are built from SS304 or SS316L stainless steel (selected according to solvent and corrosion conditions)
Smooth internal surfaces reduce dead zones and make cleaning easier
Hygienic nozzles, manways and sealing options are available for pharmaceutical and food applications
2. Compact Layout and Simplified Operation
Because the Soxhlet extraction, dynamic extraction, vacuum concentration and solvent recovery subsystems are integrated:
Piping is simplified, reducing installation work and potential leak points
Operators can control all stages from one explosion-proof HMI touch screen
Start-up, shutdown and recipe changes are faster and easier compared with separate equipment sets
This compact, “all-in-one” design can save space and reduce project complexity at the plant level.
3. Explosion-Proof & Safety Design
For processes using ethanol or other flammable solvents, safety is critical. Our stainless steel Soxhlet extractor can be configured with:
Explosion-proof motors and electrical components
Proper earthing and bonding for all major vessels and pipelines
Explosion-proof HMI touch-screen control cabinet for operation in classified areas
Safety interlocks and alarms on temperature, vacuum, level and solvent flows
This engineering approach supports compliance with local safety standards and makes the system suitable for hazardous-area installations.
4. Automation, Data -Friendly Transparency
To meet modern expectations for traceability and process understanding:
PLC-based control allows recipe management (time, temperature, vacuum, cycle counts)
Operation data can be logged and exported to support batch records, GMP documentation and audits
Clear parameter display on the HMI makes the process transparent and easier to validate
Frequently Asked Questions (FAQ)
1.What is a stainless steel Soxhlet extractor?
A stainless steel Soxhlet extractor is an industrial machine that applies the Soxhlet extraction principle (repeated washing of solids with hot condensed solvent) using stainless-steel vessels and process equipment. The Nanjing Hjchem design integrates Soxhlet extraction, dynamic extraction, vacuum concentration and solvent recovery in one unit.
2.How is it different from a traditional glass Soxhlet apparatus?
Glass Soxhlet apparatus is used at lab scale for small samples. Our stainless steel Soxhlet extractor is designed for kilogram to ton-scale batches, with vacuum, solvent recovery, explosion-proof electrics and PLC-HMI control for industrial production.
3. Can the different subsystems run independently?
Yes. The Soxhlet extraction system, dynamic circulation extraction system and vacuum concentration / solvent recovery system can be flexibly combined for linked operation or run separately as independent systems, depending on your process needs.
4. What are the benefits for heat-sensitive products?
By using vacuum reflux extraction, the boiling point of the solvent is reduced and extraction can be performed at lower temperatures. This minimizes loss of heat-sensitive active ingredients and reduces the dissolution of plant proteins into the extract, improving final product quality.
5. Which industries can use this equipment?
The stainless steel Soxhlet extractor is widely applicable to botanical and herbal extraction, traditional Chinese medicine preparations, nutraceuticals, food and beverage ingredients, cosmetics and selected fine chemical processes where clean, controllable solid–liquid extraction is required.
6. Does Nanjing Hjchem provide customized solutions?
Yes. Nanjing Hjchem Equipment Co.,Ltd offers fully customized design, including tank volumes, material (SS304/SS316L), degree of automation, explosion-proof configuration and integration with upstream and downstream equipment such as solid liquid extraction tanks, vacuum concentration units and molecular distillation systems.