8/10/2019 Film and Dropwise Exp
1/2
1. Abstract
The two main function of the film and drop wise condensation
unit is to observe the
process of heat transfer during condensation process and to
collect experimental data for
better theoretical understanding system. We are able to see
bench top unit with an
integrated steam generator and air extraction in the unit.
Furthermore, the special about
this unit is the main component are specifically designed
condenser for the observation of
both filmwise and dropwise condensation about the differences of
them. The aims that we
want to achieve are to study the heat transfer coefficient and
the heat flux and the effect
of air inside the chamber. Condensation is the process when
vapour changes to liquid
state with large heat transfer coefficient. On the other hand,
film wise condensation
occurs on a vertical or horizontal plane when a film of
condensate is formed on surface.
By using Nusselt equation, the heat transfer coefficient is able
to be calculated. Nusselt
assumed that the heat transfer that occurs from the vapour
through film and to the wall is
conduction. From there we are able to do the calculation on the
heat transfer coeeficient
since we assume the process is conduction through Nusselt.the
obtained data from this
experiment are Tsat, Tsurf, Tinand Tout.
(Film and drop wise condensation unit,Solution Engineering Sdn
Bhd )
2. Introduction
In condensation process there are two kinds, which are filmwise
and dropwise. In
filmwise condensation, a laminar film of vapour is created upon
a surface. Then, the film
flow downwards and increasing in thickness as additional vapour
is picked up along the
way. Meanwhile in dropwise it flow downwards and accumulating
static droplets below
them along the way. Furthermore, Dropwise condensation occurs
when the rate of
condensation is low or the liquid does not wet the wall.
Additional, film condensation is
most expected in an industrial part because of the large mass
flux condensed liquid per
unit length of wetted area.
As additional information, dropwise condensation was first
recognized by Schmidth
et al in 1930and much interest was inspired by their report that
heat transfer coefficient
were 5 and 7 times found with film condensation. The application
of this experiment in
any industry is to increase the heat efficiency of heat
transfer. For example, vapour power
