Boiler Blowdown Percentage and Rate calculation || How to calculate boiler blowdown percentage||

What is boiler blowdown?
Boiler blowdown means a certain volume of water is blown off through blowdown valve and is automatically replaced by feed water to maintain the desired level of total dissolved solids (TDS) in the boiler water.
Boiler feedwater usually contains a lot of dissolved and undissolved solids which is measured in total Dissolved Solids (TDS) contents in the boiler. These dissolved solids do not evaporate or escape during steam production and supply and settled at the bottomed the boiler shell or mud drum. These TDS causes serious trouble in boiler ie increase in scaling, corrosion, carryover localized overheating that may cause boiler tube failure or boiler explosion. Conductivity measurement is used for monitoring the overall TDS present in the boiler. A rise in conductivity indicates a rise in the “contamination” of the boiler water.

[@Member319]

Is this also the calculation for a water pipe boiler 74bar and max 140t/u? Do I need to use the conductivity from the drum and feedwater?

[@erpawan6886]

No, you don't need to use conductivity.

[@erpawan6886]

But as you know Feed water usually contains one limiting component such as chloride, sulfate, carbonate, or silica. Even if the component is not conductive, as is the case with silica, its concentration is usually proportional to a component that can be measured by conductivity. Therefore, conductivity is a viable measurement for monitoring the overall total dissolved solids present in the boiler. A rise in conductivity indicates a rise in the “contamination” of the boiler water.

[@Member319]

@@erpawan6886 We analyze silicate and conductivity before and after a cation filter. We now focus on the conductivity after the cation filter

[@Member319]

and we measure the conductivity of course of the feed, 4,3 - 8,0 (µS/cm

[@shrikantkale9287]

nice video..

[@erpawan6886]

Thank you bro. Please stay connected for more informative videos.

[@talibsakit4590]

Naseem Daraghmeh

[@Ashika_1234]

Formula of tds calculate

[@erpawan6886]

Thanks for contacting us,
Your question is really very good and it is our pleasure to give reply it.
Boiler Blow Down Calculation Formula
The blowdown rate can be calculated with Following Formula
qBD = qS fc / (bc - fc)
Where:-
qBD is blowdown rate in kg/h
qS is steam consumption in kg/h
FC is Total Dissolved Solids - TDS - in the feed water is ppm
bc is maximum allowable Total Dissolved Solids - TDS - in the boiler water in ppm