Carel SA0AALI000, Design Manual

Page: 16 / 36

16
ENG
“ultimateSAM - design” +03U0071EF - rel. 2.0 - 20150301
To determine the absorption distance of an ultimateSAM distributor:
1.
Calculate the saturation-ratio (SR)
SR =
(RH
a
- RH
b
)
(100 - RH
b
)
RH
a
: relative humidity after distributor
RH
b
: relative humidity before distributor
2.
With the obtained value, it is possible to determine the absorption (Da)
reffering to graphs in Figs. 4.d and 4.e or 4.a
3. Choose the configuration with an absorption distance (Da) that is less
than the requirements of the specific application.
Example SAB* / SAT*: Assume that a site has the following conditions:
•
Distributor, SATQOLI200, top-feed, “L” configuration (See example 2 in
section 4.1)
•
RH upstream of distributor: RHb=10% @ 15ºC (59ºF)
•
RH downstream of distributor: RHa=82%
1.
Calculate the SR-ratio
SR =
(82-10)
(100 - 10)
= 0.8
2. Using Fig.4.d for 152mm (6”) o.c., the absorption distance (Da) is 750
mm (30”) for this distributor.
Note: If this absorption distance is too large, the “H” configuration
with an absorption distance of only 600 mm (24”) can be used.
Example SA0: application with an SA0FALI0*0 distributor:
•
relative humidity upstream of the distributor RHb: 24%@25°C [77°F]
•
relative humidity downstream of the distributor RHa: 80%, the ratio SR is
therefore:
SR =
(50-24)
(100 - 24)
= 0.34
Figure 4.f shows, for a single upright, an absorption distance of around 400
mm [16”].
0
200
400
600
800
1000
1200
1400
0 0,2 0,4 0,6 0,8 1
0
8
16
2 4
3 2
4 0
4 8
56
Tair 25°C (77°F)
Tair 15°C (59°F)
0
200
400
600
800
1000
1200
1400
0 0,2 0,4 0,6 0,8 1
0
8
16
2 4
3 2
4 0
4 8
56
Tair 25°C (77°F)
Tair 15°C (59°F)
Lunghezza di assorbimento, interasse lance 152 mm
Rapporto di saturazione
Lunghezza di assor
bimen
to
A
bsor
btion distanc
e
Absorption distance, 152 mm (6”) o.c. (mm on left, inches on right)
Saturation Ratio
Fig. 4.d
0
200
400
600
800
1000
1200
1400
0 0,2 0,4 0,6 0,8 1
0
8
16
2 4
3 2
4 0
4 8
56
Tair 25°C (77°F)
Tair 15°C (59°F)
Absorption Distance, 76 mm (3”) o.c. (mm on left, inches on right)
A
bsor
btion distanc
e
Saturation Ratio
0
200
400
600
800
1000
1200
1400
0 0,2 0,4 0,6 0,8 1
0
8
16
2 4
3 2
4 0
4 8
56
Tair 25°C (77°F)
Tair 15°C (59°F)
Lunghezza di assorbimento, interasse lance 76 mm
Lunghezza di assor
bimen
to
Rapporto di saturazione
Fig. 4.e
To calculate the absorption distance of the lance single SA0 has been
accepted the formula Gundacker.
As an example is shown below the trend of the absorption distance for a
spear SA0LALI000 in external temperature conditions of 0 ° C (32 ° F) and the
air speed inside the UTA equal to 2.97 m / s (585fpm)
0
500
1000
1500
2000
2500
0,15 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 0,99
Tair 15°C (59°F)
Tair 25°C (77°F)
Absorption distance [mm]
Saturation Ratio
Absorption distance, single pipe SA0
Fig. 4.f
4.4 Backpressure effects on atmospheric
humidifiers
The backpressure (PB) of the ultimateSAM distributor may affect the
operation of atmospheric humidifiers. For example, the maximum
backpressure acting on the outlet of Carel atmospheric humidifiers is:
•
UEX: 1300-2000 Pa (5-8 in H
2
O), varies with model size
•
UG: 2000 Pa (8 in H
2
O)
•
UR: 1500-2000 Pa (6-8 in H
2
O), varies with model size
Note: Condensate drains can also be affected by the pressure
within the distributor. See section 7.3 for additional information.
These considerations can influence the choice of distributor (see Fig.4.a). If
the backpressure of the selected distributor exceeds the operational limits
of the steam supply, a different configuration can be chosen to reduce the
backpressure.
The total backpressure of an ultimateSAM distributor system comes from
3 sources.
•
PB1: The backpressure of the distributor itself (see tables 4.c.d.e).
•
PB2: The backpressure of the inlet adapter installed on the distributor (see
tables 4.f )
•
PB3: The backpressure of the connecting hose(s) or pipe(s) between the
atmospheric humidifier and the ultimateSAM distributor (see tables 4.g)
The backpressure generated by the distributor itself (PB1) depends on four
factors:
•
Height of uprights (that is, the number of nozzles)
•
Width of header (that is, the number of uprights)
•
Distributor configuration
•
Humidification load (H)
To calculate the backpressure of the distributor, use the equation:
FORMULA FOR SAB* / SAT* FORMULA FOR SA0*
P
B1
= A H
100
( (
2
P
B1
= 3A H
100
( (
2
P
B1
: backpressure in kPa (in H2O)
A: constant in kPa (in H2O)
H: humidification load in kg/h (lb/h)
Note : for the value of A use Table 4.c, going down column A until the
row corresponding to the 4th character of the code.
Tables 4.c.d.e. give the value of the constant “A” for each distributor
configuration. The calculated value may vary ±10% or ±0.1 kPa (½ in H2O),
whichever is greater.