Short Path/Wiped Film Distillation, Evaporation, Concentration, Vacuum Distillation

Keys to the superiority of this process include short residence time of the feed liquid, a significantly lowered temperature due to high vacuum capability, and optimal efficiency in mass and heat transfer. The brief (seconds) exposure of feed liquid to heated walls is due in part to the slotted wiper design which forces the liquid downward with strict control of residence time, film thickness, and flow characteristics. High quality components, state-of-the-art fittings and materials, and total quality control during all phases of design, fabrication and testing result in equipment of the highest performance possible.

Many applications require more than one pass through a still. Turnkey pilot or process plants typically incorporate two or more stills in series (often a WFE followed by a Molecular Still) for optomized processing.

Another equipment version, the Hybrid Still, is also available for heat sensitive materials having close boiling points. Incorporating a WFE and Fractional Column, this configuration is described in its own section.

Feed liquid is admitted into still under vacuum, immediately spread into a very thin film and forced quickly down the evaporation surface. Heated walls (orange) and high vacuum (yellow) drive the more volatile components (distillate) to the closely positioned internal condenser as the less volatile components (residue) continue down the cylinder. The resulting fractions, thus separated, exit through individual discharge outlets. Depending on application, the desired product is either the distillate or the residue fraction. Condensable low MW compounds collect in cold trap upstream of vacuum system. For high solvent loads, an optional external condenser may be installed immediately downstream of the still. (With external condenser incorporated, the internal condenser may be removed to provide a typical "WFE" or Wiped-Film Evaporator configuration.)

Although all Pope Wiped-Film Stills utilize the proven thin wiped-film process, the overall system design can vary greatly according to applications and requirements. Processing and Pilot plants generally include molecular still(s), vacuum pumps, feed and discharge pumps, vapor trap, instrumentation, plus specific equipment as required to provide complete turnkey operation. A typical system includes a wiped-film evaporator (WFE) with external condenser for high percentage solvent removal. Another option, the Hybrid Still, substitutes a packed column still for the external condenser, providing continuous multi-plate fractionation for heat sensitive materials.

Standard	4" Combination Molecular Still/Evaporator	6" 316L Pharmaceutical Evaporator

Basic 2" molecular glass lab still, No. electric heater. Also available in stainless steel.	Portable semi-pilot plant utilizes standard glass components on a custom support structure. Designed for versatility, utilized for pharmaceutical intermediate studies and production.	Utilized for production of high purity final intermediates. Skid and frame are completely 316-L stainless steel. Explosion proof for Class I, Group D, Div. I environment.

6" Two Stage Molecular Still System

The unit, as pictured, is completely self-contained (including full instrumentation) and ready for evaporation and/or molecular distillation operation by itself, or in combination with existing processes. Continuous or batch, single or two-stage modes, may be selected. The 2.36 sq. ft (0.22 sq. m) 316 stainless steel still bodies (glass or Hastelloy also available) allow feed rates from 2 to beyond 50 liters/hour, depending upon the application. Vacuum levels from 300 torr to better than 0.001 torr, and temperatures from ambient to beyond 400 degrees Celsius are possible.

6" Production Biomaterial Concentrator/Evaporator	12" Molecular Distillation Plant

Fully explosion-proof 316L stainless steel system for concentration of delicate synthetic peptides after HPLC purification processing. Such systems typically replace rotary evaporators as processes are scaled up.	Complete turnkey processing system incorporates baffled degasser / devolitizer 1st stage, 12" (1 sq. m surface area) molecular still 2nd stage. Dual cold traps permit continuous operation. Used for fatty acid stripping from food oils, and related applications.

Two-stage 316 ss Turnkey System	Versatile 6" 316L ss Molecular Still
Both stages include internal and external condensers, stainless steel vessels. Complete control console includes alarms. Designed for wide range of applications including monomer removal from polymers.	With glass degassing stage, recycle capability, continuous feed and discharge. Complete turnkey operation and controls. Designed for viscous oil and vitamin separations plus deodorization.

20" Molecular Still System

System shown incorporates jacketed 20" still body with 2.3 sq. m surface area, plus baffle type degasser stages. Equipped for high vacuum (to 0.001 torr) and high temperature (to 350°C), this unit is capable of a wide variety of applications.

Applications Assistance, Testing, and Custom Toll Processing Services Available

Pope Scientific Inc. designs custom still systems to fit nearly any application, requirement and budget. Process-dedicated or versatile development units are available. Application specialists are on hand to discuss customer projects, from feasibility and preliminary design through installation, training and after-sale consultation. Typically, projects are initiated by customer's submission of an "Applications Questionnaire" and, when appropriate, trial sample processing in Pope's well-equipped testing laboratory. Total confidentiality is maintained.

For situations where the client requires larger volume samples or production lot quantities quickly, or else chooses outsourcing over equipment procurement, Pope also offers Toll Processing Services.