Wärme - und Stoffübertragung

, Volume 13, Issue 1–2, pp 137–143

# Axiale Diffusion in Dampfkondensatoren bei Inertgasbelastung

• P. G. Kosky
• H. Jaster
Article

## Zusammenfassung

In einer Modell rechnung wird die Höhe der Mischzone zwischen Gas und Dampf in einem Kondensator bestimmt. Die mitgeteilte Gleichung ist algebraisch einfach und enthält den dimensionslosen Ausdruck zi*, der auch zahlreiche verwandte Probleme charakterisieren sollte:
$$z_i^* = z_i \sqrt {\frac{{4U\Delta T_0 \tilde RT_0 }}{{pD_0 R\tilde h_{fg} }}} .$$
Mitgeteilte Daten bestätigen das mathematische Modell.

### Nomenclature

c

Gas phase concentration

D

Binary mass diffusion coefficient

h

Molar enthalpy

hfg

Molar latent heat of vaporization

k

Thermal conductivity

L

Characteristic length

N

Molar flux

p

Total pressure

pv

Vapor pressure

q″

Surface heat flux

R

R

Universal gas constant

T

Absolute temperature

T

Ambient temperature

t

Wall thickness

U

Overall heat transfer coefficient

y

Vapor mole fraction

z

Axial coordinate

z*

Non-dimensional axial coordinate (z-zo)/l

### Greek

δ

Non-dimensional temperature approach

ΔT0

Overall temperature difference

Π0

Vapor pressure constant

Φ

Non-dimensional temperature (T-T)/ΔT0

### Subscripts

G

Pertaining to gas

i

Pertaining to upper extremity of interfacial zone

L

Pertaining to liquid

V

Pertaining to vapor

0

Pertaining to lower extremity of interfacial zone

# Axial diffusion in gas blanketed vapor condensers

## Abstract

A model is given, which permits determination of the height of a zone of mixing between a gas and a vapor in a condenser. The resulting predictive equation is algebraically simple and contains a non-dimensional group, zi*, which should characterize a host of related problems:
$$z_i^* = z_i \sqrt {\frac{{4U\Delta T_0 \tilde RT_0 }}{{pD_0 R\tilde h_{fg} }}} .$$
Data are presented which verify the mathematical model.

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### References

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