Cag purification LTE3 HGV, Installation, Operation, Maintenance And Parts Manual

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GB
2.4 CORRECTION FACTORS
Correction factor for operating pressure changes :
Inlet air pressure psig 60 70 85 100 115 130 140 155 170 200 218
barg 4.1 4.8 5.9 6.9 7.9 9.0 9.7 10.7 11.7 13.8 15.0
Factor (F1) 0.70 0.85 0.93 1.00 1.06 1.11 1.15 1.18 1.21 1.25 1.28
Correction factor for ambient temperature changes :
Ambient temperature ºF 80 90 100 110 113
ºC 26.7 32.2 37.8 43.3 45.0
Factor (F2) 1.09 1.06 1.00 0.90 0.83
Correction factor for inlet air temperature changes:
Air temperature ºF 90 100 110 113
ºC 32.2 37.8 43.3 45.0
Factor (F3) 1.15 1.00 0.82 0.75
Correction factor for DewPoint changes:
DewPoint ºF 38 40 44 47 50
ºC 3.3 4.4 6.7 8.3 10.0
Factor (F4) 1.00 1.05 1.10 1.15 1.20
How to find the air flow capacity: How to select a suitable dryer for a given duty:
Air flow
capacity
=
X
Factor
(F1)
Factor
(F2)
X
Factor
(F3)
X X
Factor
(F4)
Nominal
duty
= ÷
Factor
(F1)
Factor
(F2)
÷
Factor
(F3)
÷ ÷
Factor
(F4)
Design
air flow
Std. air
flow rate
Minimum
Example: Example:
A LTE 5 has a nominal duty of 15 scfm (26
Nm
3
/h). What is the maximum allowable flow
through the dryer under the following operating
conditions:
− Inlet air pressure = 85 psig (5.9 barg)
−
Ambient temperature = 110 °F (43.3 °C)
− Inlet air temperature = 110 °F (43.3 °C)
−
Pressure DewPoint = 38 °F (3.3 °C)
Each item of data has a corresponding numerical
factor as follows:
The procedure here is to list the operating
conditions and then to locate the corresponding
numerical factors:
−
Design air flow = 9 scfm (15 Nm
3
/h)
−
Inlet air pressure = 85 psig (5.9 barg)
− Ambient temperature = 110 °F (43.3 °C)
−
Inlet air temperature = 110 °F (43.3 °C)
− Pressure DewPoint = 38 °F (3.3 °C)
In order to select the correct dryer model the
required flow rate is to be divided by the correction
factors relating to above mentioned parameters:
Air flow
capacity
=
X X X X
0.93 15 0.90 1.00 0.82
= ÷
÷ ÷
÷
0.93 9 0.90 1.00 0.82
Std. air
flow rate
Minimum
= 10.3 scfm (17.5 Nm
3
/h) → This is the
maximum flow rate that the dryer can accept
under these operating conditions.
= 13.1 scfm (22.3 Nm
3
/h) → Therefore the
model suitable for the conditions above is LTE 5
(15 scfm, 26 Nm
3
/h - nominal duty).