Evaporation measurement device

Evaporation Pan meter , Pan Evaporimeter
Advantages and Disadvantages of Pan Evaporimeter.
Power point presentation for project description with summery.
Classification for pan evaporimeter.
Methods of Evaporation measurements

1. Evaporation Measurement Device Presentation By Bhawani Shankar Gaurav Mewara

2. Evaporation means simply vaporization from the surface of liquid. Vaporization of a liquid below its boiling point. Thus no boiling occurs and the rate of vaporization depends on the diffusion of vapour through the boundary layers above the liquids. Evaporation

3. When heat applied in solution the motion of molecules increase and moleclues present in the surface overcome the surface tension of the liquid And it evaporates because surface molecules have less cohesive force than others. Mechanism

4. Temperature Surface area Agitation Atmospheric aqueous vapour pressure Atmospheric pressure on the liquid under evaporation Type of product required Economic factors. Factors affecting the evaporation

5. Natural Circulation Evaporator Evaporating pans Evaporating stills Short tube evaporator Forced circulation evaporator Film evaporator Equipment used for evaporation

6. On a manufacturing scale, liquid extracts containing water are evaporated in open pans called evaporating pans. Evaporating Pans T he amount of evaporation is a function of temperature, humidity, wind and other ambient conditions.

7. Fig : Stilling Well Fig : Evaporation Pan

8. The evaporation pan of this standard set is made of stainless steel It has the dimensions of a “class A“ evaporation pan, namely 54 mm ( 0 inches) in height and 206 mm (47.5 inches) in diameter. The evaporation pan is installed on the wooden support Daily the result of evaporation and precipitation is measured within the still well, by means of a high quality evaporation micrometer with a measuring range of 00 mm and an accuracy of 0.02 mm Procedure

9. The pan is installed in the field. The pan is filled with a known quantity of water (the surface area of the pan is known and the water depth is measured) The water is allowed to evaporate during a certain period of time (usually 24 hours). For example, each morning at 7 o’clock a measurement is taken. The rainfall, if any, is measured simultaneously. After 24 hours, the remaining quantity of water (i.e. water depth) is measured. The amount of evaporation per time unit (the difference between the two measured water depths) is calculated; this is the pan evaporation: E pan (in mm/24 hours) The principle of the evaporation pan

10. They are simple easy and cheap to construct. They are easy to use and clean. Stirring of the evaporating liquids can be done easily. Advantages

11. The whole of the liquid is heated all the time which may lead to decomposition of the components On the evaporating surface foam is rapidly formed which decreases evaporation. This pan can only be used for evaporating aqueous and thermostable liquid extracts. They can not be used for evaporating extracts containing organic solvents like alcohol etc. Disadvantage

12. Thank You