Book contents
- Frontmatter
- Contents
- Preface
- Introduction
- Part I Experiments in heat transfer
- I.1 Conduction
- I.2 Convection
- I.3 Boiling
- Experiment 17 Capillary-tube boiling
- Experiment 18 Two characteristic regions of nucleate pool boiling and corresponding change of hydrodynamic state
- Experiment 19 The boiling slide
- Experiment 20 Evaporation and boiling in sessile drops on a heated surface
- I.4 Mixing, dispersion, and diffusion
- I.5 Radiation
- I.6 Heat pipes and exchangers
- Part II Experiments in thermodynamics
- Appendix 1 Experiments and demonstrations in thermodynamics
- Appendix 2 Experiments and demonstrations in heat transfer
- Appendix 3 Heat-transfer and thermodynamic films
- Index
Experiment 20 - Evaporation and boiling in sessile drops on a heated surface
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- Preface
- Introduction
- Part I Experiments in heat transfer
- I.1 Conduction
- I.2 Convection
- I.3 Boiling
- Experiment 17 Capillary-tube boiling
- Experiment 18 Two characteristic regions of nucleate pool boiling and corresponding change of hydrodynamic state
- Experiment 19 The boiling slide
- Experiment 20 Evaporation and boiling in sessile drops on a heated surface
- I.4 Mixing, dispersion, and diffusion
- I.5 Radiation
- I.6 Heat pipes and exchangers
- Part II Experiments in thermodynamics
- Appendix 1 Experiments and demonstrations in thermodynamics
- Appendix 2 Experiments and demonstrations in heat transfer
- Appendix 3 Heat-transfer and thermodynamic films
- Index
Summary
Object
The objectives of this experiment are as follows:
(i) to observe the evaporation and boiling phenomena in a drop after it falls onto a heated surface,
(ii) to measure the lifetime of the drop, and
(iii) to determine the heat-transfer characteristics in the sessile drop-boiling system.
Apparatus
Figure 20.1 is a schematic of the experimental setup. It consists of a dropgenerating system and an electrically heated testing surface with a thermal measurement device.
The liquids used in the drops are carbon tetrachloride, benzene, methyl alcohol, and distilled water.
A liquid fills a bottle equipped with a stopcock which is attached to a support and hangs over the heated surface. A needle valve regulates the rate of dripping flow from the bottle through a no.-1/4 hypodermic needle. The liquid is released from the needle in the form of drops 2 to 3 mm in diameter which fall at regular intervals.
In order to generate drops of identical size, a drop receiver is used to collect the drops until they fall at a steady, desired rate.
At the start of the experiment, the receiver is quickly displaced via the action of a spring to allow only a single drop to fall onto the center of the heated surface.
A center rest-pin is installed on the drop receiver to produce two-dimensional movement (in order to prevent drop-receiver vibration).
- Type
- Chapter
- Information
- Experiments in Heat Transfer and Thermodynamics , pp. 147 - 154Publisher: Cambridge University PressPrint publication year: 1994