For many high-value products in pharmaceuticals, botanicals, fine chemicals and food ingredients, solid–liquid extraction is the first critical step in the production chain.
When you need highly efficient, repeatable extraction with complete solvent recycling, an Industrial Soxhlet Extractor offers a proven, science-based solution.
Nanjing Hjchem Equipment Co.,Ltd designs and manufactures stainless steel industrial Soxhlet extraction systems with integrated solvent recovery, vacuum, and explosion-proof control.
Our systems translate the classical Soxhlet principle used in laboratories into a robust, automated industrial process.
If your process requires deep, efficient solid–liquid extraction with controlled solvent recycling, an Industrial Soxhlet Extractor may be the ideal solution.
What Is a Soxhlet Extraction?
A Soxhlet extraction is a solid–liquid extraction technique in which a solid sample is repeatedly washed with fresh portions of hot solvent, using a special reflux and siphon arrangement. Originally developed for analytical chemistry, Soxhlet extraction allows:
Continuous washing of the solid with clean, condensed solvent
High extraction efficiency without constant manual solvent exchange
Full recycling of solvent within a closed system
In a classical Soxhlet apparatus, the system consists of:
A flask containing the solvent
A Soxhlet body (extraction chamber) holding the solid sample in a thimble
A condenser that cools vapor back into liquid
The hot solvent vapor rises to the condenser, condenses, drips onto the solid, and accumulates in the chamber. Once the liquid level reaches a certain height, it siphons back into the boiling flask, carrying dissolved solute with it. This cycle repeats many times, progressively extracting the soluble components from the solid.
An Industrial Soxhlet Extractor applies the same principle at a much larger scale, with engineered stainless-steel vessels, solvent recovery tanks and process control.
Industrial Soxhlet Extractor by Nanjing Hjchem – System Configuration
Stainless Steel Industrial Soxhlet Extraction System
Nanjing Hjchem Equipment Co.,Ltd provides Industrial Soxhlet Extractor systems built in corrosion-resistant stainless steel, typically SS304 or SS316L, depending on the solvent and process requirements. A typical system includes:
1. Stainless Steel Extraction Tank
Main vessel for solvent boiling, extraction and initial mixing
Jacketed for heating and cooling
Designed for efficient solid–liquid contact and easy cleaning
Can be integrated as a pre-extraction or combined extraction/boiling tank depending on customer process
2. Stainless Steel Soxhlet Extraction Tank / Chamber
Specially designed Soxhlet extraction chamber where the solid material is held
Engineered for repeated solvent percolation and siphoning cycles
Internal structures optimized to ensure uniform wetting and efficient mass transfer
Easy to charge and discharge solids, with appropriate manways and sanitary connections
3. Solvent Recovery Tank
Dedicated solvent recovery tank for collecting extract-rich solvent
Can be linked to vacuum concentration equipment or distillation units for solvent recycle and extract concentration
Designed for safe handling of flammable solvents, including appropriate venting and explosion-proof fittings
4. Water-Ring Vacuum Pump
Provides stable vacuum for reduced-pressure operation
Lowers solvent boiling point, enabling lower-temperature extraction and improving energy efficiency
Especially valuable for heat-sensitive botanicals, flavors and pharmaceuticals
5. Explosion-Proof Electrical System
Explosion-proof motors, wiring and junction boxes where needed
Explosion-proof instrumentation for hazardous zones
System design aligned with local safety regulations and typical ATEX-like requirements for areas handling flammable solvents
6. Explosion-Proof HMI Touch-Screen Control Cabinet
Centralized touch-screen HMI panel for operating the Industrial Soxhlet Extractor
PLC-based control for temperature, vacuum, cycle time, solvent levels and safety interlocks
Recipe management and data logging, supporting GMP and quality documentation
Explosion-proof design, allowing installation in classified areas when required
This integrated configuration ensures that your Industrial Soxhlet Extractor is not just a set of tanks, but a coherent, automated solid–liquid extraction solution.
Procedure for Soxhlet Extraction (Industrial Perspective)
Procedure for Soxhlet Extraction in Industrial Systems
While lab Soxhlet extraction uses glassware, an Industrial Soxhlet Extractor from Nanjing Hjchem uses stainless-steel tanks, vacuum and automated controls. A typical procedure involves:
1. Charging the Solid and Solvent
The solid raw material (herbal pieces, filter cake, pellets, etc.) is loaded into the stainless-steel Soxhlet extraction chamber or into an upstream extraction tank, depending on process design.
The solvent (e.g., ethanol–water mixture or other suitable solvent) is charged into the extraction tank or solvent reservoir.
2. Heating and Solvent Vapor Generation
The extraction tank is heated via a jacket (steam, hot water or thermal oil).
Solvent begins to evaporate, generating vapor that flows toward the Soxhlet extraction chamber.
3. Condensation and Washing of Solids
Vapors reach a condenser or cooled zone and condense into liquid.
The condensed solvent flows into the Soxhlet extraction section, continuously dripping over the solid bed.
As the solvent passes through the solid, it dissolves target components (oils, actives, flavors, etc.).
4. Siphoning and Solvent Recirculation
The extract-rich solvent accumulates in the Soxhlet chamber.
When the liquid reaches a triggering level, the siphon mechanism returns the solvent to the solvent recovery / boiling tank.
This cyclic operation repeats until extraction endpoints are reached (determined by time, sample analysis, or process control logic).
5. Vacuum and Temperature Control
A water-ring vacuum pump can be used to reduce the boiling point of the solvent, allowing lower-temperature operation for heat-sensitive products and improving energy efficiency.
Temperature and pressure are monitored and controlled via sensors and the explosion-proof HMI touch-screen control cabinet, ensuring stable conditions throughout the Soxhlet cycles.
6. Separation, Concentration and Solvent Recovery
After extraction, the mixture is discharged to a solvent recovery tank, where further separation, decantation or concentration can be performed.
Solvent is recovered by distillation or evaporation and reused, minimizing waste and operational costs.
The spent solids are removed for disposal or further processing.
Through this engineered procedure, an Industrial Soxhlet Extractor turns the classical Soxhlet method into a scalable, controllable and safe production process.
Advantages of Nanjing Hjchem Industrial Soxhlet Extractor
1.Process expertise in solid–liquid extraction
We understand both what is a Soxhlet extraction and how to translate it into robust industrial equipment, combining theoretical principles with practical design.
2.Stainless steel construction and hygiene
All product-contact parts are made from stainless steel (SS304 or SS316L), offering corrosion resistance, cleanability and long service life.
3.Complete system integration
Our Industrial Soxhlet Extractor includes the extraction tank, Soxhlet extraction chamber, solvent recovery tank, water-ring vacuum pump, explosion-proof electrical system and explosion-proof HMI control cabinet as one integrated package.
3.Customization for pilot and industrial scales
We can supply:
- Pilot units for scale-up, optimization and pre-commercial production
- Full-scale industrial systems for continuous manufacturing
Frequently Asked Questions (FAQ)
1.What is a Soxhlet extraction?
A Soxhlet extraction is a solid–liquid extraction technique where a solid sample is repeatedly washed with fresh portions of hot condensed solvent in a cyclic siphoning system. It allows thorough extraction using a relatively small quantity of solvent, which is continuously recycled.
2.How does an Industrial Soxhlet Extractor differ from lab glassware?
Lab Soxhlet uses glass flasks and small Soxhlet bodies, suitable for gram-level samples. An Industrial Soxhlet Extractor from Nanjing Hjchem uses stainless-steel tanks and chambers, solvent recovery vessels, vacuum systems and explosion-proof control to handle kilogram to ton-scale loads under safe, automated conditions.
3. Is Soxhlet extraction suitable for all solid–liquid extraction processes?
Not always. Soxhlet is especially useful when deep extraction and efficient solvent recycling are required, and when the solid matrix benefits from repeated washing with clean hot solvent. For some processes, conventional agitated extraction tanks or percolation systems may be more suitable. Our engineers can help you choose the best approach.
4. What materials are used in your Industrial Soxhlet systems?
Our Industrial Soxhlet Extractors are built primarily from SS304 or SS316L stainless steel for all product-contact parts. Selection depends on solvent, temperature and hygiene requirements. Special materials can be considered for particularly corrosive applications.
5. Can the system be integrated with concentration and distillation?
Yes. The solvent recovery tank in our Industrial Soxhlet Extractor can be connected to vacuum concentrators, distillation columns and molecular distillation systems for solvent recycling and product concentration. This creates a complete solid–liquid extraction and purification line.
6. Are explosion-proof features available?
Definitely. For flammable solvents such as ethanol, we offer explosion-proof motors, electrical components and an explosion-proof HMI touch-screen control cabinet, designed according to local explosion protection standards and hazard zoning.