Example
The maximum steam flow rate which is set through expansion option 36.4 as 20,000lb/hour.
Blowdown Time BD
1 BD2 BD3 BD4
Time between Blowdowns T1 T2 T3 T4
In this example the 4 blowdowns are configured with the total blowdown timings (Repeats x Duration)
as:
BD
1 = 10s at T1 00:00
BD
2 = 10s at T2 06:00
BD
3 = 10s at T3 14:00
BD
4 = 10s at T4 18:00
For period 2, if the average steam flow rate for that period from the M.M. steam flow metering is
12,000lb/ hour, than the calculated steam flow ratio is then:
12,000
⁄
20,000
⁄
0.6
The total configured blowdown time over the 24 hours is:
10101010
40
The maximum blowdown time for period 2 is:
06:0000:006
So therefore the adjusted blowdown time is then:
24
0.6640
24
6
The Maximum blowdown time for period 2 is 13s. Therefore a full 6s blowdown will be carried out.
The maximum blowdown time for period 3 at full steam rate of 20,000lb/hr is:
014:0006:008
So therefore the adjusted blowdown time is then:
24
1840
24
13.3
The Maximum blowdown time for period 3 is 10s. Therefore 3.3s is carried over to period 4.
Time Reduced Bottom Blowdown for Standalone
When using the time reduced bottom blowdown in standalone operation, the maximum steam flow rate
and the average steam flow rate are taken from the 4-20mA input to the bottom blowdown module.