RAC 214.01 | Evaporation Process Demonstration Unit

During the generation of vapor, the medium that is to evaporate runs through different flow forms dependent on the heat transfer area. The medium flows into a tube evaporator as a fluid and exits the tube evaporator as superheated vapor. In practice, the water vapor generated in big systems is used e.g. for heating plants or machine drives. To design steam generators, it is important to have knowledge of the evaporation process with the boiling crises in order to ensure reliable operation. Boiling crises are caused by a sudden deterioration of the heat transfer, whereby the high heat flux density leads to a dangerous increase in the wall temperature.

The experimental unit can be used to examine and visualize the evaporation process in its various flow forms. This is done by heating evaporating liquid, in a tube evaporator made of glass. Compared with water, this liquid has the advantage that its boiling point is at approx. 18°C (1013hPa), whereby the entire evaporation process takes place at much lower temperatures and a lower heating power. The pressure can be varied via the cooling circuit. A water jet pump evacuates the evaporation circuit.

Experimental Capabilities

• Observation of typical forms of evaporation.
• Single phase liquid flow.
• Sub-cooled boiling.
• Slug flow.
• Annular flow.
• Film boiling.
• Dispersed flow.
• Single phase vapor flow.
• Wet steam.
• Effect on the evaporation process by:
• Flow rate.

Circuit Diagram

The circuit diagram of Evaporation Process Demonstration Unit is given bellows such as: Evaporation in tube evaporator:

• Sub cooled fluid.
• Initial Boiling Point.
• Bubbly Flow.
• Slug Flow.
• Annular Flow.
• Dispersed Flow.
• Superheated Flow.
• Boiling Range.
• Blue: fluid Temperature, Grey: Heating Surface Temperature.