Rotary evaporators: for efficient distillation

Structure of a rotary evaporator

The main components of a rotary evaporator system are the heating bath, the steam tube with evaporator flask and the vacuum pump. The latter can sometimes be purchased together with the rotary evaporator, but in some models it is not included. In principle, the construction consists of the following parts:

• Heating bath (usually with water, but in some circumstances also with oil)
• Evaporator flask with steam tube
• drip catcher, which prevents any foaming solvent from splashing into the cooling coil
• rotating shaft
• heat sink
• Woulff's bottle, which protects the vacuum pump from condensed liquid
• Collecting flask
• vacuum pump with vacuum controller
• Lift to lower the evaporating flask into the water bath (can be electrical or mechanical)

The solution to be separated is thus filled into the evaporating flask, which is attached to the rotating shaft together with the drip catcher. When the apparatus is operated, the evaporated solvent rises through the vapor tube, condenses in the cooler and then collects in the collection flask. The lift can be used to lift the evaporator flask out of the water bath or immerse it there. You can also find out more about the separation of mixtures in our guide.

Rotary evaporator - function

The most important components of the rotary evaporator are, as mentioned before, the heating bath, the steam tube (with the evaporation flask at the bottom), the vacuum pump or the condenser with the vacuum attachment. In the apparatus, the evaporator flask is heated, which causes the substance to be distilled (i.e. the solvent in the solute) to evaporate in the heating bath. This distillation or vapor flows through the vapor tube directly into the condenser, where it forms a precipitate on the cooling surface. The condensate is collected in the receiver flask. The separation of the substances is achieved by the fact that their boiling points differ and some substances evaporate faster at a given temperature, while the others still remain. By applying a vacuum, solvents can evaporate even faster than at normal pressure. Thus, the necessary heat for the evaporation of the solvents is reached more quickly. The difference between this process in a rotary evaporator and a normal (vacuum) distillation apparatus is that the latter has an approximately uniform temperature. In the rotary evaporator, on the other hand, most of the heat supplied is consumed in evaporating the liquid film formed by the rotation on the flask wall.

How a rotary evaporator is used

A rotary evaporator is thus basically a vacuum distillation apparatus whose evaporator flask is set in rotation and rotates around its own axis. There are two main advantages to this:

• Vacuuming allows evaporation at lower temperatures, which is especially important when the solute is temperature-sensitive.
• The rotation causes a steady, thin film of liquid to form on the flask wall. The total surface area of the liquid increases and evaporation is faster.

In principle, this device can be used to separate both solids and liquids from the solvents. Thus, it is used in chemistry, scientific research, industry and occasionally even in gastronomy.

Note: However, the rotary evaporator is not suitable for some applications: If the boiling points of the components to be separated are too close, separation is not possible. An example of this is mixtures of methanol and ethanol, where other processes become necessary.

Buy Rotary Evaporator - Manufacturer in MedSolut.com assortment

Are you looking for a rotary evaporator of a certain brand for your laboratory? MedSolut.com has devices from all leading manufacturers ready for you. Upon request, our expert advisors will be happy to inform you about the advantages and disadvantages of each company.

Heidolph

With Heidolph we have one of the market leaders for rotary evaporators in our program. The Franconian company has outstanding expertise in this field and convinces with innovative new developments. The Heidolph rotary evaporators can be divided into the product lines Hei-VAP Core, Hei-VAP Expert, Hei-VAP Ultimate, Hei-VAP Expert Control and Hei-VAP Ultimate Control. You can configure the systems according to your needs using a plug-and-play system. For industrial use, there is a range of particularly powerful large rotary evaporators.

IKA

The IKA Group manufactures high-quality laboratory technology for various applications - from shakers and magnetic stirrers to heating technology and the rotary evaporators discussed here. You will find a wide range of products: from entry-level units such as the RV 3 to automatic systems with integrated vacuum controllers.

KNF

KNF Neuberger stands for safe, excellent laboratory solutions and also has two different rotary evaporators in its portfolio. The RC 600 and RC 900 models feature an innovative piston exchange system and are particularly user-friendly.

Phoenix Instrument

The rotary evaporator from Phoenix Instrument has a 1500 m² cooling surface, a motor-driven lift and a heating bath that can be heated up to 180 °C. The lift is equipped with a safety function and automatically lifts the flask out of the heater in the event of a power failure.

Shimadzu

The Japanese manufacturer Shimadzu is a specialist in instrumental analysis equipment and continues to set new standards in laboratory technology with its innovative technologies. At MedSolut we have two rotary evaporators from Shimadzu ready for you, each with motorized lift, 3-liter heating bath and integrated vacuum controller.

Buying a rotary evaporator - versions and variants

The basic equipment is always similar - but beyond that, there are different design variants depending on the manufacturer and product series. You are unsure which product variant is necessary or suitable for your application? Our experts from the service team will be happy to advise you without any obligation.

Hand lift or motorized lift

The lifting and swiveling device used to position the evaporator flask in the heating bath can be either mechanically or electrically driven. In the first case it is a manual lift, in the second a motorized lift. The electric drive offers an additional level of convenience, but is usually associated with a higher price.

Integrated vacuum controller

You can purchase a rotary evaporator either without a vacuum pump and connect it separately, or choose a system with an integrated pump. Also, in some cases, a control unit for the vacuum pump is integrated on the control panel, allowing you to conveniently control pressure, temperature and rotation from one place. If you want an integrated vacuum controller, we recommend, for example, the models Hei-VAP Expert Control, Hei-VAP Ultimate Control or the ""RV 10 auto"" series from IKA.

Automatic module

If larger quantities have to be distilled or if distillation has to be carried out over a longer period of time, an additional automatic module can be a helpful addition. Depending on the type of unit, for example, additional solvent is automatically added to the evaporating flask as soon as a certain quantity has evaporated. At the same time, the distillate is continuously discharged into a collection container and the residue in the evaporating flask is extracted at regular intervals. This makes it possible to run the unit in unattended continuous operation. If you want to use this feature, we recommend, for example, one of the ""Distimatic packages"" from Heidolph.

Rotary evaporator price - what are the costs?

The price of a rotary evaporator can vary greatly - depending on what features and add-ons you need. Some manufacturers offer packages with add-ons, such as a vacuum pump, control panel, tubing or glassware, which are then naturally more expensive accordingly. For example, an entry-level model such as IKA's RV 3 FLEX starts at around €2,100, while at Heidolph you pay just over €3,000 for the basic Hei VAP Core model. The professional versions and packages are usually in the €6,000-12,000 range, such as the RV 10 auto pro FLEX model from IKA with vacuum controller at €8,526.00 or the Hei VAP Expert Control Package Automatic Evaporation with vacuum pump and recirculating chiller at €9,390.00.

Our experts from the MedSolut team will be happy to advise you on a sensible range of functions for your application!

Accessories for rotary evaporators

At MedSolut.com you can get numerous accessories and extensions for your rotary evaporator, so that you can equip it according to your needs. Of course, you can always order additional or spare parts from the appropriate manufacturer from us afterwards. For example, ask for:

• Evaporator, or collecting flasks
• distillation spiders
• drip catchers or foam stoppers
• Woulff bottles
• Protective covers
• Hose sets
• Sealing rings
• Heating bath fluid
• Vacuum pumps
• Vacuum valves
• Coolers
• control and monitoring units
• terminals
• corresponding software

Our claim is to sell high-performance technology with a long service life. Therefore, we are also available after commissioning as your contact when it comes to maintenance and replacement of components.

Buying a rotary evaporator - we are happy to help you!

A rotary evaporator has become an indispensable part of many laboratories, as it enables the rapid distillation of solvents. Whether you are looking for a basic model or a large industrial unit, MedSolut.com has a wide range of products for you. On request, we can help you find the right model for your application. Please contact us for a non-binding consultation by phone (+49 30 2096579 00) or e-mail([email protected]).