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Scilogex Rotary Evaporators at 5 L and 20 L

A rotary evaporator removes solvent from a sample by rotating the flask in a heated bath under reduced pressure, so the solvent boils at a temperature low enough to leave the product intact. This collection carries the Scilogex SCI100-S and SCI100-Pro at 5 L and the SCI20L-Pro at 20 L, each with a choice of vertical coiled or dry ice condenser, plus a replacement coiled glass condenser.

Three things happen at once in a rotovap and each contributes. Rotation spreads the liquid as a thin film over the flask wall, which increases surface area dramatically and speeds evaporation. The bath supplies heat gently and evenly rather than at a hot spot. Vacuum lowers the boiling point, so a solvent that would need 80°C at atmospheric pressure comes off at 40°C. The result is that thermally sensitive material survives a process that would otherwise degrade it.

The specification most often chosen wrong is the condenser, and the consequence is not a slower run. It is a damaged vacuum pump.

→ Part of Laboratory. Also see Distillation Systems, Vacuum Pumps & Aspiration, Water Baths & Chillers and Hotplates & Stirrers.

Coiled Condenser or Dry Ice Condenser?

A vertical coiled condenser circulates chilled fluid through a glass coil and handles most common solvents. A dry ice condenser packs solid carbon dioxide into a cold finger, reaching much lower temperatures for solvents that will not condense on a circulated-fluid coil.

Solvent that does not condense passes straight through into the vacuum pump, where it contaminates the oil, degrades the achievable vacuum and shortens pump life. For low-boiling solvents such as dichloromethane, diethyl ether or pentane, a dry ice condenser is the correct specification rather than an upgrade.

Condenser	Suits	Running Requirement
Vertical coiled	Water, ethanol, ethyl acetate and most common solvents	A chiller or circulating bath; no consumables
Dry ice	Low-boiling solvents that will not condense on a coil	A reliable dry ice supply; no chiller needed

Coiled condenser models: the SCI100-S 5 L, the SCI100-Pro 5 L and the SCI20L-Pro 20 L. Dry ice versions: the SCI100-S 5 L and the SCI100-Pro 5 L.

A replacement vertical coiled glass condenser is stocked separately. Condensers are glass and are the component most likely to break, whether from thermal shock or handling, so a lab running a rotovap daily is well served keeping a spare rather than losing a week to a single break.

5 L or 20 L, and S or Pro?

Flask capacity sets the maximum batch, but a flask should be filled to roughly half its nominal volume at most, so a 5 L system handles a working volume of around 2 to 2.5 L per run. Sizing on nominal capacity alone leads to a rotovap that turns out to be too small for the batches you had in mind.

The liquid needs room to form a rotating film, and it needs headroom above it. That headroom is what protects against bumping: if a solution superheats and boils suddenly, liquid is thrown up the vapour path into the condenser, contaminating the recovered solvent and potentially carrying product where it should not go. Underfilling, ramping vacuum gradually rather than pulling straight to full, keeping bath temperature moderate and fitting a bump trap all reduce it. Overfilling makes it much more likely.

Scale-up at 20 L

The SCI20L-Pro is the larger platform here, for work that has outgrown a 5 L system. Larger flasks are also heavier when loaded, so consider how the flask will be handled on and off the instrument, particularly at the end of a run when the operator is tired and the flask is expensive.

S or Pro

The Pro models offer more control over rotation speed and bath temperature than the S versions. For routine solvent removal either works. For method development, for work that has to be reproducible between runs, or for an instrument shared across a group, the finer control removes a source of variation between operators.

What Else the System Needs

A rotary evaporator is one component of a system. Buying only the rotovap leaves you unable to run it.

A vacuum source. Diaphragm pumps are the usual choice because they are oil-free and chemically resistant to solvent vapour. A pump with vacuum control that regulates to a setpoint is considerably easier to work with, since solvent removal proceeds at a controlled rate rather than as fast as the pump can pull. See Vacuum Pumps & Aspiration.
A chiller or circulating bath for coiled condenser systems, sized to remove at least as much heat as the bath is adding. An undersized chiller means solvent passes through uncondensed, which hurts both recovery and pump protection. See Water Baths & Chillers.
Glassware. Evaporating flasks, receiving flasks and a bump trap, plus spares. A system without a receiving flask cannot run, and glassware breaks.

Frequently Asked Questions

How does a rotary evaporator work?

The flask rotates in a heated bath while the system is held under vacuum. Rotation spreads the liquid as a thin film over the flask wall, greatly increasing surface area for evaporation. Vacuum lowers the solvent's boiling point so it evaporates at a much lower temperature than it would at atmospheric pressure. The vapour travels to a condenser, condenses, and collects in a receiving flask. The result is efficient solvent removal at a temperature that does not degrade thermally sensitive material.

Should I choose a coiled condenser or a dry ice condenser?

A vertical coiled condenser circulates chilled fluid and handles water, ethanol, ethyl acetate and most common solvents. A dry ice condenser reaches much lower temperatures and is needed for low-boiling solvents such as dichloromethane, diethyl ether or pentane that will not condense on a coil. Using a coil for a solvent it cannot condense sends vapour into the vacuum pump, contaminating the oil and shortening pump life.

How full should the evaporating flask be?

Roughly half its nominal capacity at most. The liquid needs room to form a rotating film and headroom above it to reduce the risk of bumping. A 5 L system therefore handles a working volume of around 2 to 2.5 L per run, so sizing on nominal flask capacity alone leads to a system that is effectively too small for the batches you intended.

What is bumping and how do I prevent it?

Bumping is when a superheated solution boils suddenly and violently, throwing liquid up the vapour path into the condenser. It contaminates recovered solvent and can carry product where it should not go. Reduce it by underfilling the flask, ramping vacuum gradually rather than applying full vacuum immediately, keeping bath temperature moderate, and fitting a bump trap between the flask and the vapour duct.

What vacuum pump does a rotary evaporator need?

A diaphragm pump is the usual choice because it is oil-free and chemically resistant to the solvent vapour it will encounter. A pump with vacuum control that regulates to a setpoint makes the process considerably easier to manage than an uncontrolled one. Match the pump's ultimate vacuum to the boiling points you need to reach, since a pump that cannot pull deep enough will not bring high-boiling solvents off at a safe bath temperature.

Do I need a chiller as well?

For a coiled condenser system, yes. The condenser needs a supply of chilled fluid, and the chiller should be sized to remove at least as much heat as the bath is adding. An undersized chiller means the condenser cannot keep up, solvent passes through uncondensed, and both recovery and pump protection suffer. Dry ice condenser systems do not need a chiller but do need a reliable dry ice supply.

What is the difference between the S and Pro models?

The Pro versions offer finer control over rotation speed and bath temperature. For routine solvent removal either works. For method development, for reproducible work, or for an instrument shared across a group, the additional control removes variation between operators and between runs.

Are replacement condensers available?

Yes, and it is worth knowing before you need one. The condenser is glass and is the component most likely to break, whether from thermal shock or from handling during cleaning. A replacement vertical coiled glass condenser is stocked. In a lab that runs a rotovap daily, keeping a spare avoids a single break stopping the workflow for a week.

Can a rotary evaporator dry a sample completely?

It removes bulk solvent very efficiently but usually leaves residual solvent behind, particularly with higher-boiling solvents or where the residue is viscous. Complete drying typically requires a further step: a vacuum oven, a high vacuum line, or lyophilisation for aqueous samples.

Where should a rotary evaporator be installed?

Ideally in a fume hood or with local exhaust, since solvent vapour can escape at flask changes and at venting. Confirm placement against your facility's requirements for solvent handling, and allow clearance above and behind the unit for the condenser, tubing and vacuum lines. Bench depth is frequently the constraint that gets discovered after delivery rather than before.

MediDepot Purchasing Advantages

Price Match Guarantee: found the same model number for less elsewhere? We will match the verified price.
Equipment Financing: useful when a rotovap, pump and chiller are bought together as a system.
Extended Warranty: available on qualifying instruments.
Military Discount: available for qualifying military medical and research facilities.
Request a Quote: condenser selection, pump and chiller matching, and spare glassware.

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