Hi good morning,
I had been searching the net regarding the recommended frequency of the intermittent blowdown, however, I've only come upon recommendations that indicate that "shorter, more frequent blows are better than longer, less frequent blows," and proposed blowdown periods of anywhere between 10 seconds and 2 minutes. Some sources only say that a cleaner boiler feed water would require less frequent manual blowdown.
I would like to have a more specific and objective indication on how frequent the intermittent blowdown should be.
Just a brief history of our water treatment facility, we once used hot lime softener for our boiler feed water wherein we conduct intermittent blowdown once a day. A few years ago, we switched to RO water treatment for a better boiler water quality. However, IBD is still being conducted daily. With the improvement in water quality, I was thinking of the possibility to reduce the frequency of IBD for energy related and economic purposes.
Below are our current boiler water quality at our 600 psi boilers:
Conductivity: ~750 uS/cm
pH: 10.5-11.5
Silica: <10 ppm
Hardness at BFW: <0.5 ppm
When conducting IBD, we monitor the level of the boiler steam drum and let it drop by 10%.
Can you give me your insights regarding this matter?
Given the quality of our boiler water, can we reduce the frequency of IBD to around once a week?
Thank you and best regards,
Cwsrt