clearSTILL Wiped Film Evaporator
Two stages – one continuous cycle for superior distillation
The clearSTILL dual-stage wiped film evaporator doubles throughput and labor efficiency over any single stage equipment using continuous, two-pass distillation technology in a single contained cycle. Used for heat sensitive or highly viscous fluids, engineered wipers create a thin film on the evaporator surface that enables thin film evaporation and short path condensation.
High throughput, Dual Stage Wiped Film Evaporator
Most traditional wiped film distillation equipment requires each distillation pass to be performed in a single, separate cycle. Not only does this create a bottleneck in the production process, it also leaves the risks of contamination and product waste between transfers. For any serious distillate producer, this should not be an acceptable standard.
With two separate thin film evaporator stills capable of a clean, continuous process and a throughput rate of 4-6 L per hour, the clearSTILL is capable of eliminating waste and contamination, doubling throughput and halving labor costs compared to standard single stage systems.
Wiped Film units are optimal for distilling thermally sensitive compounds and very viscous oils. The short residence time preserves the products from degradation and the wipers that are incorporated in the still create a thin film that will improve mass transfer and thereby improve efficiency. Since the condenser is internal to the thin film evaporator, it is considered a short path distillation unit. Because the vacuum system produces a very high vacuum, the system is also considered to be molecular distillation
How Wiped Film Distillation Works
The clearSTILL has an impressive 4-6 Liter/Hour throughput capacity – double the capability of standard single-pass distillation machines. This level of production efficiency can effectively halve labor costs all while creating a streamlined distillation process.
The process of molecular distillation is aided strongly by a vacuum system that conditions the vacuum space in the short path region.
This program also contains programmable methods that enable automated process control with reporting for enhanced compliancy with GMP data integrity requirements. This machine is crafted with certified stainless-steel materials that support global market requirements.
Double Your Throughput and Labor Efficiency
Data Integrity and Process Control
Unlike standard distillation equipment, the clearSTILL is built with total process control in mind. User authentication and programmable methods allow for a full-coverage of the distillation process. This includes tracking of throughput and yields, optional WiFi enabled monitoring and control, data visualization, and hardware control.
This level of process overview gives the clearSTILL capability of lot, calibration and maintenance tracking, and barcode reporting both electronically and through a paper trail. These capabilities are essential for advanced distillation technology that is compliant with current GMP requirements.
clearSTILL Wiped Film Evaporator Specifications
Dimensions: L 103″ x W 44″ x H 72″
Roughing Vacuum Pumps: 2
Feed Pumps: 1
Heating Jacket: All tubes, pumps
Condensate Pumps: 2
Power (kW): 9
Turbo Vacuum Pumps: 2
Retentate Pumps: 2
Heating Range: 38 – 260° C
Diffusion Pump: Optional
Feed Rate: up to 50 kg/hr
Wiped Film Pressure (torr): 0.1
Number of Condensers: 2
Distillation Vessels: 2
Short Path Pressure (torr): 0.001
Condenser Surface Area (cm2): 606
Cold Finger: Yes, Inline
Cooling Range: -15 – -1° C
Cooling Capacity: (1) 0.45kW at -35oC, (2) 0.5kW at 30oC
Cold Finger Surface Area (cm2): 577
Chiller Fluid: 35/65 glycol/water
Collection Vessel Volume: 7L
Wiped Film Evaporator Cost, Features and Advantages
- Continuous operation eliminates contamination & reduces maintenance costs
- Continuous integration flow with fracTron
- Dual still allows for continuous passes
- No maintenance roughing pump eliminates need to tear down frequently
- High throughput increases overall production value
- Data logging for mass flow, vacuum allows method troubleshooting
- Manual bypass for turbo
- Dual turbo gives flexibility
The clearSTILL technology sets itself apart in terms of efficiency, product quality and maintenance reduction by removing bottlenecks that are typical in single stage distillation equipment. This allows for a system that is tailored for an optimized distillation process that is beneficial to the manufacturer by offering the best possible wiped film evaporator cost and creating a superior distillate overall.
Double Your Throughput and Labor Efficiency
Critical Training Available for Wiped Film Distillation Equipment
What is the best distillation method for your business? There are many considerations including costs, capacity and potency.
Read Distillation Publications
Learn More About clearSTILL Wiped Film Evaporator
Download the product brochure to check detailed specifications and important information about the equipment.
Frequently Asked Questions
How do I clean the distillation equipment?
Using canola oil, the system is cleaned according to a predefined cleaning protocol.
Why do vacuum pumps require maintenance?
Vacuum pumps typically use an oil ring to produce a seal that creates vacuum. Volatiles in the winterized oil that don’t condense during degassing can follow the vapor flow path all the way to the vacuum pump, contaminating the pump lubricating oil, compromising its performance.
The clearSTILL vacuum pumps don’t require oil for operation, eliminating that maintenance.
What is a finger cleaner and how do you automate cleaning of the finger?
The “finger” of a wiped film evaporator is the condenser and must be cleaned due to cross contamination of the condenser from lot to lot. Many machines require cleaning the condenser between batches or lots. This requires that the condenser be cleaned between batches. An automated cleaner sprays a cleaning solvent over the condenser, cleaning it. The finger is heat flashed to dry.
What is the difference between wiped film evaporation, falling film evaporation, and short path distillation and spinning band distillation?
All of these technologies utilize the same physical property to achieve separation of a liquid mixture – differences in boiling points. The primary differences are heat transfer technologies of the evaporative and condensing surfaces, and the path the vapor travels from one to the other. A “film” is an efficient way of achieving high evaporation rate because heat and mass transfer resistance decreases as the film thickness decreases. A film can be achieved on the evaporator surface if the viscosity is favorable to allow a film to form or if a mechanical wiper assists in producing the film.
- Wiped film evaporation creates a thin film along the evaporative surface using spinning wiper blades and is typically used with highly viscous mixtures.
- Falling film evaporation typically addresses a fluid that can produce a free flowing film without any mechanical assistance. This generally applies to fluids with viscosities with 2 cP or less. In falling film evaporation, a liquid mixture flows down a heated column to evaporate a volatile component. These columns commonly have tubes to improve heat transfer and increase the evaporative surface area.
- Short path distillation utilizes a round bottom flask, heating mantle, and glass condenser situated on top of the round bottom. Material is introduced to the round bottom flask, the heating mantle heats the mixture until components volatilize. The volatile components that are vaporized are carried to another chilled vessel to recondense. The technique is largely batch in nature.
- Spinning band distillation is a short path distillation system with a special helical condenser situated at the top of the apparatus that provides better precision on the volatile component being condensed. Most short path distillation systems use single straight tube condensers that require greater difference in boiling points in order to separate.
Does the location of the vacuum sensor matter?
The measured vacuum level will change depending on where you measure the vacuum. If you measure inside the wiped film column, you will measure a much greater pressure due to the volatile components in the vacuum. As those volatile components diffuse through the vacuum system, they encounter a series of condensers which act to condense those vapors. Vacuum sensors on the downstream side of the condenser often measure much lower vacuum.
Various manufacturers place vacuum sensors in different locations and successfully produce distillate.
What vacuum level is required?
For degassing, it is recommended that the wiped film evaporator operates at < 1 torr, this can be achieved with the scroll vacuum pump that comes with the system. For distillation, it is recommended to use a turbo vacuum pump as well as a scroll pump to reduce the temperature required to vaporize the cannabinoids. Turbo pumps can achieve a vacuum level of <0.001torr.
Does the system come with methods?
Methods comprising temperatures, pressures, flow rates, and alarm settings are provided. Methods must be adjusted for desired distillation rate, color and potency.
How do I remove colors from winterized extracts?
Depending on the operating conditions, wiped film distillation systems won’t vaporize color-causing impurities in the winterized oil. Typical results vary and depends on differential temperature between the wall and the cold finger, and pressure.
What yield should we expect from the wiped film evaporator? What is the potency of the distillate?
Yield and potency are highly dependent on the aggressiveness of the operating conditions. For example:
- The boiling point of ethanol is 78oC. If the evaporator temperature is set at 100oC above the boiling point, it is expected that most of the ethanol will evaporate and condense and the ethanol yield will be high. However, the exceedingly high temperature can cause other components to also vaporize, decreasing the potency of the distillate product.
- If the temperature is set at the boiling point of ethanol, it is likely that some of the ethanol will evaporate, but not all. Thus, the yield of ethanol will be comparatively much lower than in the aforementioned case, but the distillate product will have fewer impurities.
The clearSTILL has been engineered to achieve a throughput of 4-6L/hr and increase the potency from 50-65% in winterized oil to 65-90% in the distillate depending on the standard operating procedure
What is entrainment and how do I prevent it?
- Entrainment comes from inadequate degassing. Highly volatile components (gasses, residual solvents, etc.) aggressively vaporize on the heated surface, causing liquids to contaminate the headspace and the condenser. Thus, oil components that have not been evaporated contaminate the distilled oil.
- Special entrainment separator wiper design is required to eliminate entrainment.
What is the surface area of the unit and how does that impact throughput?
- 0.6 m^2. Smaller the number, the slower the throughput. As the amount of temperature controlled surface area decreases, the unit functions at a lower throughput and efficiency, and with higher impurities. This stems from having increased control over highly viscous liquids and vapors at their saturation temperatures and pressures.
- Having evenly heated evaporative and condensing surfaces maximizes throughput and minimizes impurities by gently evaporating volatile components from a highly viscous mixture. The surface area for heat transfer is fully utilized by the use of wipers to evenly distribute the mixture on the heated surfaces. Controlling the wiping speed and feed inlet flow allows for precise control over residence time of evaporation and chemical potential between the evaporative and condensing surfaces.
What is the footprint, power, and heat load for the equipment?
- L 103″ x W 44″ x H 72″, 80 FLA at 230VAC, 50/60 hz, 3 phase
- Heat load of equipment is estimated at 3000 W-hr
What extraction method will give the cleanest distillate?
- Specially denatured ethanol is typically used for ethanol extraction due to the high cost of pure 200 proof ethanol.
- Denaturants are comprised of a wide variety of toxic and non food grade chemicals. Those denaturants are always detectable in the final distillate.
Input requires decarboxylated oil.
- Input for requires winterized crude oil.
- Input requires decarboxylated oil.
- First wiped film evaporation stage: degassing
- Degassing involves removal of volatiles and gas with heat while stirring. Typical ethanol removal is 80-90% using a rotovap or falling film evaporator, degassing using a wiped film evaporator achieves >98% ethanol removal which is required for wiped film evaporation.
- Degassing can be done with a stirred tank reactor, but the disadvantage of degassing with a stirred tank reactor is degradation of active targets such as CBD or CBG and breakdown of the oil. This method is also commonly a batch, compared to the continuous operation of a wiped film evaporator. – Aaron
- Second wiped film evaporation stage: distillation
- Degassed, winterized oil is wiped onto the heated exterior surfaces of the wiped film evaporator column where the more volatile cannabinoids vaporize into the headspace. The internal condenser condenses the cannabinoid vapors to produce the distillate product. The pressure of the system is GREATLY reduced to decrease the boiling point of the target cannabinoid products. Lower boiling points prevent product degradation and decrease heat load requirements.
- If you choose to degas with a stirred tank reactor, both stages of the clearSTILL wiped film evaporator can be set to distillation operating conditions to achieve a high purity distillate. – Aaron
- Output distillate often feeds either chromatography or crystallization processes.
What does a wiped film evaporator (wfe) do?
- Also known as molecular distillation, the system is similar to short path distillation equipment in the sense that there is a short distance between the evaporator and condenser. Depending on the operating conditions, wiped film evaporators can degas winterized oil or distill degassed winterized oil. The distillation column is comprised of a permeable vertical cylinder and a rotating wiper blade that wipes a thin film of winterized oil over the evaporative surface. The condenser is typically only 1-2 inches away from the evaporator so that when the volatile components begin to evaporate into the headspace, they migrate towards the chilled surface of the condenser and condense to a liquid, distillate product.
- Degasses winterized oil.
- Makes distillate from degassed winterized oils.
- Removes color, terpenes, flavor, and other impurities.
- Makes oil consistent so that it can be used in a product for consistent results.
- Upgrades potency of target distillate.
What is the advantage of a dual still?
- Continuous degassing and distillation in a continuous two step operation that will yield a first pass distillate.
- If operating with only distillation parameters, increased distillation production and better control of the distillate product with no handling required in between operations.
Certifications and Standards
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Meet Our CEO and Founder Dr. Jon Thompson, Ph.D
Dr. Thompson is a separations scientist, entrepreneur, and inventor. As a scientist, he has a strong technical background and industry experience in analytical instrumentation, in-vitro diagnostics, biotech, mining, and homeland security markets. During his cannabis industry career, Dr. Thompson has earned a strong track record of winning and implementing medical cannabis licenses in well-regulated, medically-modeled states. Dr. Thompson has assisted numerous companies to attain their goals in cannabis and hemp manufacturing, as well as market development, strategic marketing, and worldwide business-to-business alliance formation (including international markets).