A rotary evaporator is often used with a water bath. A rotary evaporator works by reducing the pressure over a solution using a vacuum pump, thereby reducing the boiling point of the liquid. As the liquid evaporates quickly, it pulls heat from the solution. That heat needs to be replaced so the evaporation does not stop. A water bath below the rotating flask provides that heat. A water bath is not a good substitute for a rotary evaporator, so your second question regarding equivalent temperatures does not make sense to me. The reason why people use a rotary evaporator is so they do not have to boil the solution at high temperature, protecting the sample from heat damage.
A typical rotary evaporator has a water bath that can be heated in either a metal container or crystallization dish. This keeps the solvent from freezing during the evaporation process. The solvent is removed under vacuum, is trapped by a condenser and is collected for easy reuse or disposal.
What is a water bath?
A water bath is a laboratory equipment used to keep water at a constant temperature for incubating samples in a laboratory. A lab equipment water bath always has a digital interface to allow users to set a required temperature. A laboratory water bath is a preferred heat source for heating flammable chemicals instead of an open flame to prevent ignition.
What is the function of a laboratory water bath?
The application range of lab equipment water bath includes reagents warming, substrates melting or cell cultures incubation, as well as used to enable certain chemical reactions to occur at high temperature. Since almost all laboratory water bath has a digital interface to allow users to set a required temperature, usually, an indicator light turns on to indicate that the water bath is working. Once the correct temperature is reached, the laboratory water bath turns on and off to maintain a constant temperature.
Some water baths, known as shaking water baths, provide additional controls that allow users to control the speed and frequency of the movements. Used primarily to mix two substances together, a shaking water bath can be used instead of a standard water bath by turning the shaking mechanism off.
A lab equipment water bath does not necessarily contain water. The fluid used depends on various factors, including the required temperature range and necessary viscosity of the fluid. Sometimes oil is used in a water bath, instead of water. Water baths can be dangerous when working with flammable substances, such as oil, so safety precautions must be taken, including using the water bath on a stable, level surface.
Types of laboratory water bath
1. Circulating water baths are ideal for applications when temperature uniformity is critical, such as enzymatic and serologic experiments. Water is thoroughly circulated throughout the bath resulting in a more uniform temperature.
2. Non-circulating water baths relies primarily on convection instead of water being uniformly heated. Therefore, it is less accurate in terms of temperature control. In addition, there are add-ons that provide stirring to non-circulating water baths to create more uniform heat transfer.
3. Shaking water baths has extra control for shaking, which moves liquids around. This shaking feature can be turned on or off. In microbiological practices, constant shaking allows liquid-grown cell cultures grown to constantly mix with the air.
