Sludge precipitated in HP Dosing (TSP) stainer

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Sludge precipitated in HP Dosing (TSP) stainer

Hello,

Today we found some kind of slurry sludge in the HP dosing pump stainer.

What can be the issue related to this?

Attached few photos.

COMMENT BY WATER NETWORK ADMIN (In HP Dosing Phosphate especially Tri sodium phosphate is added at the  boiler  drum which is operating at high pressure (so called  HP dosing  system) through  HP dosing  system. If it is  dosed  at feed pipe, it may react with impurities and sludge may be deposited at the feed line.)

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  1. Not having much to utilize other than the color of the deposit in the pictures and your description there is a significant probability it is Magnesium phosphate.  If this yellowish material turns white as it dries, the chances of it being magnesium phosphate are 99.8%. Now if it is Mag phos, the situation you have is a little more serious that gunk at the dosing pump strainer. Either you are making down your TSP with poor water or you have poor make-up water quality or you have a H/E leak some place.  You need to do a cycle chemistry test to see what you water quality it. Are you measuring cat conductivity on your return condensate?

    1 Comment

    1. Trisodium phosphate will take the pH in the feed line to (without looking it up) about a 12.  This is at the point where you would get both Ca and Mg reaction with PO4 and precipitate. 

      1  on a high pressure boiler you should be using a good softener, with no hardness at all going to the feed line or to the boiler.

      2  What in the world caused someone to put in a TSP program on a high pressure boiler.  Phosphate cycles for this type of operation went away in the 60s. and earlier.  

      3  If you need to get the alkalinity up, for some reason, you should be using NaOH or KOH in your treatment program.  Not soda ash or TSP.  

      4  If you want PO4, there area a lot of other phosphate salts that will not raise the alkalinity and precipitate most things right out of solution.  Remember the first course in analiytical chemistry - qualitative analysis.  

      5  The cheapest PO4 to purchase is phosphoric acid and neutralize it yourself with KOH or NaOH.  In most cases with boiler treatment the KOH is the way to go because we are usually adding a lot of sodium already to the water treatment as sodium acylates and sodium phosphonates.

      6  Why are you not using a phosphonate such as HEDP and/or AMP instead of PO4 which can precipitate and form a Calcium PO4 Sludge. 

      7 Perform a complete water analysis for both the incoming water and the   actual feed water which is diluted by the returning steam condensate.  Also perform a full analysis on the steam condensate. Perform a full analysis on the soft water makeup.  Now then the Feedwater to the boiler is a combination of incoming water, steam condensate and feed water - look for problems and know what is happening for all water sources.

      8 Good luck

      You can send be a direct text if you still have problems.  wh@bluevalleylabs.com

       

      Waymon