To explain some terms, which we use here, we attach a diagram
which shows how the steam is produced.
The diagram shows 3 stages, while water is transformed into
superheated steam.
The vertically axis of temperature starts with freezing temperature.
The second point it is both 100oC and boiling point (at atmospheric
pressure).
This point grows every time when the pressure grows and decreases
when the pressure diminishes. The last temperature point replies
to superheated steam
The horizontal axis of the diagram shows three stages of warmth
content in steam, “h” is a sensible heat of water, “I” is a
next stage – latent heat needed to change the state of matter
– transformation from water to steam, without temperature increase.
Latent heat depends on temperature and while the pressure
increases the latent heat insignificantly diminishes.
At the third stage, which replies to superheated steam, every
growth of warmth is connected with direct increase of temperature.
Relationship between humidity and steam – it is often used
term – relates to proportion of latent steam fraction.
If the humidity level amounts to zero then the steam is dry
– and this is that what we need and any amount of heat added
in this moment would bring about transformation into superheated
steam.
If steam contains some fractions of humidity it means, that
water is delivered as suspension and we deal with wet steam.
We have already stressed that it is needed to use dry steam
or superheated steam, but absolutely avoid wet steam.
Practically, temperature in connection with pressure let us
know with what kind of steam we deal.
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