Nordmann ES4 - 4 Notes for the Planning Engineer; Selecting the Unit Version; Calculating the Maximum Required Steam Capacity

21
4.1 Selecting the unit version
To select the unit version the following planning steps are required:
1. Calculating the required maximum steam capacity according chapter
4.1.1
2. Selecting the unit version from the table in chapter 4.1.2
4.1.1 Calculating the maximum required steam capacity
The maximum required steam capacity must be calculated based on one
of the following formulas:
V • ρ
m
D
= • (x
2
- x
1
)
1000
4 Notes for the planning engineer
m
D
: maximum steam demand in kg/h
V: volume of supply air portion per hour in m
3
/h (for indirect room humidi-
cation) or room volume to be humidied per hour in m
3
/h (for direct
room humidication)
ρ: specic gravity of air in kg/m
3
ε: specic volume of air in m
3
/kg
x
2
: desired absolute room air humidity in g/kg
x
1
: minimum absolute supply air humidity in g/kg
The values for ρ, ε, x
2
and x
1
can be gathered from the h,x-diagram or
the Carrier-Diagram for moist air respectively.
Important notes:
– The required maximum steam capacity depends on the specic ap-
plication and the installation. The calculated steam capacity based on
the above formulas, the h,x diagram and the condition of the air to be
humidied does not consider any steam loss (e.g. due to condensa-
tion in the steam hoses and the steam distributors), any heat loss of
the unit as well as any absorption or release of humidity of materials
located in the room being humidi ed.
In addition, the calculated steam capacity does not consider any losses
caused by the draining rate depending on the water quality as well as
any losses occur if the steam humidier is operated on a mains circuit
with a ground fault circuit interrupter.
The total amount of losses depends on the entire system and must be
taken into consideration when calculating the required steam capac-
ity. If you have any questions regarding the calculation of the steam
capacity please contact your Nordmann supplier.
– For systems where the max. required steam capacity varies extensively
(e.g. for test facilities or for systems with variable air volume ow, etc.),
please contact your Nordmann supplier.
or
V
m
D
= • (x
2
- x
1
)
1000 • ε