Correction Factors - morse AHT 20 Manuel D'instructions

Correction factor for operating pressure changes :
Inlet air pressure
Factor (F1)
Correction factor for ambient temperature changes:
Ambient temperature
Factor (F2)
Correction factor for inlet air temperature changes:
Air temperature
Factor (F3)
Correction factor for DewPoint changes:
DewPoint
Factor (F4)
How to find the air flow capacity:
Air flow Nominal Factor
=
X
capacity duty (F1)
Example:
An AHT 150 has a nominal duty of 150 scfm
3
(255 m /h). What is the maximum allowable flow
through the dryer under the following operating
conditions:
Inlet air pressure = 120 psig (8 barg)
−
Ambient temperature = 105° F (40° C)
−
Inlet air temperature = 195° F (90° C)
−
Pressure DewPoint = 45° F (7° C)
−
Each item of data has a corresponding numerical
factor as follows:
Air flow
150 1.07
= x
capacity
= 137 scfm → This is the maximum flow
rate that the dryer can accept under these
operating conditions.

2.5 CORRECTION FACTORS

psig 60 80
barg 4 5.5
0.79 0.91
ºF ≤ 80
ºC 27
1.22
ºF 140
≤
ºC 60
1.25
ºF 35-40
ºC 1.5-4.9
0.80
Factor Factor
X X
(F2) (F3)
0.94 0.91
x x
x
100 120
7 8
1.00 1.07
90 100
32 38
1.11 1.00
160 175
70 80
1.14 1.02
41-45
5-7
1.00
How to select a suitable dryer for a given duty:
Minimum
Factor Design
=
Std. air
X
(F4)
air flow
flow rate
Example:
The procedure here is to list the operating
conditions and then to locate the corresponding
numerical factors:
Design air flow = 95 scfm (161 m
−
Inlet air pressure = 120 psig (8 barg)
−
Ambient temperature = 105° F (40° C)
−
Inlet air temperature = 195° F (90° C)
−
Pressure DewPoint = 45° F (7° 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:
Minimum
1.00
=
flow rate
= 104 scfm → Therefore the model suitable
for the conditions above is AHT 150 (150 scfm
or 255 m
140 160
10 11
1.13 1.18
105 110
40 43
0.94 0.89
180 195
82 90
1.00 0.91
46-50
7.1-10
1.08
Factor Factor
÷ ÷
(F1) (F2)
95 1.07 0.94
÷
÷
3
/h - nominal duty).
GB
180 200
12.5 14
1.23 1.27
115
46
0.83
210
100
0.80
51-54
10.1-12
1.12
Factor Factor
÷ ÷
(F3) (F4)
3
/h)
0.91 1.00
÷ ÷