How evaporation is related to Chemical Engineering process? Evaporation is regularly used in the food processing, chemical, kraft paper, and pharmaceutical industries to produce liquid concentrates. … Evaporation can be used as the initial step in producing a dried product if the liquid concentrate then undergoes a drying process such as spray drying.
There are two types of vaporization: evaporation and boiling. Evaporation occurs at temperatures below the boiling point, and occurs on the liquid’s surface.
How the process goes:
Evaporation is a phase transition from the liquid phase to the gas phase that occurs at temperatures below the boiling point at a given pressure.
For molecules of a liquid to evaporate, they must be located near the surface, be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase intermolecular forces.
Boiling is a phase transition from the liquid phase to the gas phase that occurs at or above the boiling temperature.
Boiling is the rapid vaporization of a liquid and occurs when a liquid is heated to its boiling point. A liquid’s boiling point is the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environment (air).
How to relate to chemical engineering in specific: Spray drying is a method of producing a dry powder from a liquid or slurry by rapidly drying with a hot gas. This is the preferred method of drying of many thermally-sensitive materials such as foods and pharmaceuticals.
Calculate Evaporation Using Mathematical Equations
Where:
· E = Evaporation Rate (Gallons/Day)
· A = Pool Surface Area (ft2)
· W = Wind Speed Above Pool (mph)
· P = Water’s Vapor Pressure (mmHG) at Ambient Temperature
· T = Temperature (°F)
The following equation was developed by Warren Stiver and Dennis Mackay of the Chemical Engineering Department at the University of Toronto. It can be used to estimate evaporation from the surface of a pool of liquid that is at or near ambient temperature. Please note that the equation as been modified from its general form to be applicable to calculating evaporation from swimming pools.
