Specifications

Installation
10 DRYPOINT RA 80 – 720
2.5. Correction factors
Correction factor for operating pressure changes:
Inlet air pressure barg 4 5 6 7 8 10 12 14
Factor (F1) 0.77 0.86 0.93 1.00 1.05 1.14 1.21 1.27
Correction factor for ambient temperature changes (Air-Cooled):
Ambient temperature ºC 25 30 35 40 45 50
Factor (F2) 1.00 0.99 0.97 0.93 0.88 0.81
Correction factor for inlet air temperature changes:
Air temperature ºC 25 30 35 40 45 50 55 60 65 70
Factor (F3) 1.27 1.12 1.00 0.88 0.78 0.70 0.62 0.55 0.49 0.43
Correction factor for DewPoint changes:
DewPoint ºC 3 5 7 10
Factor (F4) 1.00 1.09 1.19 1.37
How to find the air flow capacity:
Air flow capacity = Nominal duty x Factor (F1) x Factor (F2) x Factor (F3) x Factor (F4)
Example:
An DRYPOINT RA 180 has a nominal duty of 1080 m³/h. What is the maximum allowable flow through the dryer
under the following operating conditions:
– Inlet air pressure = 8 barg
– Ambient temperature = 45°C
– Inlet air temperature = 50°C
– Pressure DewPoint = 10°C
 Factor (F1) = 1.05
 Factor (F2) = 0.88
 Factor (F3) = 0.70
 Factor (F4) = 1.37
Each item of data has a corresponding numerical factor which multiplied by the design air flow is as follows:
Air flow capacity = 1080 x 1.05 x 0.88 x 0.70 x 1.37 = 957 m³/h
957 m³/h This is the maximum flow rate that the dryer can accept under these operating conditions.
How to select a suitable dryer for a given duty:
Design air flow
Minimum std. air flow rate =
Factor (F1) x Factor (F2) x Factor (F3) x Factor (F4)
Example:
With the following operating parameters:
– Design air flow = 1000 m
3
/h
– Inlet air pressure = 8 barg
– Ambient temperature = 45°C
– Inlet air temperature = 50°C
– Pressure DewPoint = 10°C
 Factor (F1) = 1.05
 Factor (F2) = 0.88
 Factor (F3) = 0.70
 Factor (F4) = 1.37
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:
1000
Minimum std. air flow rate =
1.05 x 0.88 x 0.70 x 1.37
= 1128 m³/h
Therefore the model suitable for the conditions above is DRYPOINT RA 210 (1260 m³/h - nominal duty).