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Our de-aerator conductivity is running high while de-aeration pressure is 0.3 kg/cm2g and temperature is 107 to 110 degree centigrade. Any thoughts on reasons and solutions?
 
Answers
26/02/2013 A: Siddharth Pandey, Bharat Oman Refineries Limited, Bina, siddharth.pandey619@gmail.com
The Conductivity of your steam condensate - BFW system is running on higher side due to low flow of LP steam.
Soln: DM water pressure is generally maintained around 7-7.5 Kg/cm2. At higher DM water temp. demineralized water will flash much more at lower pressure in the de aerator, eventually increasing the system pressure of de aerator, to control this increased system pressure PIC will fully open the vent steam and minimize the LP steam flow (via 2 PIC controllers).
However, for smoother operation reduce the DM water temp. to 95 oC and increase the de aerator system pressure slightly to 0.5 Kg/cm2, this will increase the LP steam flow (lower flashing of DM water) into the de aerator and allow the stripping of dissolved gases (proper contacting and mixing in the packed trays) from boiler feedwater escaping the vent loop route which will minimize the conductivity of your steam circuit.
16/05/2011 A: keith bowers, B and B Consulting, kebowers47@gmail.com
High electrical conductivity in de-aerated BFW indicates 'ions' are not being adequately removed by the de-ionizer resin beds.
16/05/2011 A: Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
There is not enough information in the question as posed to fully understand the problem.
Possible causes might be:
(a) Insufficient steam flow into and particularly out of the De-Aerator. Contributing to this might be a decrease in the preheating temperature of the water coming to the De-aerator
(b) Increased Inorganic Total Dissolved Solids [Salts] in the water coming to the De-Aerator. Inorganic Salts are not removed via de-aeration, but must be removed by some type of upstream demineralizer system.