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Topic Initiated By : Administrator
Apr 24, 2019
Category : Administrator
Organization : India Boiler Dot Com
Welcome to the General Discussion forum. We are having a number of topic specific active forums for the community members to join and have discussion on those topics. However, if you have any general query, comment, or suggestion that is not related to those topics, then you can post it in this section. To communicate to the Admin, you can also mail at info@steamingopps.com | Post | --- |
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Category : Industry Member
Organization : JSW
Is it a good practice that we are taking LP heater-4 outlet initial flushing line water tapping for boiler filling for initial cold startup from other unit? LPHeater-4 outlet temperature will be 140 degC.Please comment on thermal stress or any other issue.It is a 300MW coal fired boiler. | Post |
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Post By : Santosh Kumar Hiray (Profile)
Jun 13, 2020
Category : Industry Member
Organization : NTPC
One of the power unit of 660 MW, Flat strips for water wall welding of material grade SA 387 Grade 12 cl-2 in under procurement process. Supplier produce test certificate but unable to furnish heat treatment chart. However declare that the material in furnace normalized at 930 deg C and tempered at 600 deg C. Can it be possible to ensure the verification of heat tretment on finished product by measuring hardness or any other method? As per IBR regulation-49, one chorme half moly material hardness should be 163 HB max, can it be apply to this grade also? | Post | --- | |||
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Category : Industry Member
Organization : GAIL India Ltd.
Sir 1) As observed Silica increases in Drum > 1.2ppm - owing to colloidal silica ( Given-F.W. whose silica already < 0.02 ppm @ 105 KSC Drum Pressure), Considerable Blow down is given > 5%, it is below 0.02 ppm in MS. As the same F.W. is used in attemperation why silica in Saturated steam sampling doesn't shows up? it is just around 0.015-0.017.Is this only because Spray quantity is less compared to steam flow from drum? or just inaccurate measurement??? 2) As dissolved silica is weakly ionised, Is this the only reason it is not completley exchanged (or its slippage occurs) in MB/SBA/WBA?? 3) SAC>Degasser>SBA> MB??? ,,,,How & why WAC or WBA are sequenced into DM process if strong Acid or Strong Base are strong enough for any type exchange? | Post |
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Category : Industry Member
Organization : GAIL India Ltd.
Dear Sir As above 270 o C inside drum Colloidal Silica Converts to Reactive Silica (forming Silicic acid) which are weakly ionised & as observed from chemical lab reports have nearly no effect/impact on Drum -Conductivity or pH it abruptly increases Drum Silica only. As per discussion with you & EPRI guideline we can allowed up to 2.0 ppm silica in Drum but we are here maintaing up to 1.2 ppm & giving higher blow downs . So my querRIES:- 1. HOW THIS AMOUNT OF VERY SAFE LIMIT IS DETERMINED/RECOMMENDED (in our case 1.2 ppm instead of 2.0 ppm), is there any STANDARD/BENCH MARK BASIS according to which we may increase this limit . What I mean to say why it was not decided as 1.7 or 1.9 , why just 1.2 ppm if allowable is 2.0 ppm what was the basis of 1.2? 2.Sir, How much ideally will be the maximum blow down that can be given by CBD and IBD valves ? Considering that every CBD valve is also having bypass valve too.
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Category : Industry Member
Organization : GAIL India Ltd.
Dear Sir Adding alum to promote coagulation & forming floppy flocs (during Clarification in RWP) i.e. (Al2SO4) 3+ 6H20 --> Al (OH) 3 + 3H2SO4 leads to formation of Surface positive & insoluble hydroxide as Al(OH)3 which attracts Suspended(> 1micron) & Colloidal impurities (<0.5 microns) but as both of them are non reactive how they(suspended/ colloidal) can be classified as negatively charged ions which are then attracted by positively charged Al(OH)3 in sludge blanket ? Sir while referring various study materials I just came across a statement which says " FINE SUSPENDED PARTICLES & COLLOIDS PRESENT IN WATER CARRY CHARGES ON THEIR SURFACE & MOST OF THE COMMON MATERIALS ASSUME NEGATIVE CHARGE" & am not getting this assume thing so need your help for better clarity. | Post |
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Category : Industry Member
Organization : RIL
Fly Ash Wet Handling and its transportation: CaO + Water = > Heat and Violent Steaming: How to control? CFBC Boiler: Type IR / U Beam: Lime Dosing for SOx capture: Excess Lime in Fly ash (CaO) reacts with water and give exothermic reaction which makes violent Steaming and make truck body excessively hot along with bubbling. This is unsafe condition. How can it be avoided, if Wet fly ash handling is compulsion? | Post |
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