Any More Potential Benefits of New Oxygen Scavenging Technology?? 1

[countryham]

I have developed a new , greatly improved method of catalytically scavenging oxygen with sulfites from boiler feedwaters--almost instaneously (with a 4+ times greater catalytic result than ever thought possible in the past with any other (commonly accepted catalyst technology)--CONTROLLED within 1-2ppb precision in the economizer influent.....I know that1)this has Flow Accelerated Corrosion Benefits by controling disolved oxygen in the 4ppb (+-)1-2ppb range. I know that the sulfite usage will be reduced up to 90+ percent (which is pretty cost-insignificant given the low cost of sulfite),HOWEVER,I have received good input from peers who suggested that due to the kinetic improvement gained within deaerators (the sulfite-oxygen reaction is one of "second" order),that:the deaerator storage section's size could be reduced, thereby affecting a sizable reduction in fabrication costs....In effect, the deaerator will become a quasi in-line reactor with storage capacity....... My question is:... How much validity could be attributed to my earlier responder who suggested that a storage section size reduction is feasible???and how would/could this be determined??and By whom??Additionally,,--Can anyone think of any other uncovered benefit(s) that could be realized with this technology??..You are invited to reply, in full detail, all particulars, directly to me at john11933@sbcglobal.net if you want .. and to pass this question to design engineers whom you may know that have similar background knowledge in this area who may have other fresh ideas...Thanks,in advance, for your help.. Countryham

 

[25362]

How does sulfite chemistry compares with tannin additions for case of high % of cold make up water?

 

[countryham]

This (tannin ) question is a real supprise!!... Have only heard of tannin used as a scavenger one time before!Tannins and/or other organic materials similar to sodiumlignosulfate to prevent sludge from becoming adherent on boiler shell surfaces----which has been in boilerwater use since the use of corn cobbs,saw dust, and leaves,etc.All, will retard the oxygen-sulfite reaction..In the pulp and paper industry, tanns are a huge by-product of the kraft process and bio-oxidation ponds are used to reduce total effluent BOD.By extrapolation,I would think that the use of tanns to reduce oxygen in boiler water influent would be very poor... The use of sulfites was first introduced by a German named Gans in 1913and more widely used after 1918.Sulfites had universal acceptance by 1936.The stoichometric values for sodium sulfite and oxygen are about 8-1 but 10-1 is more common in order to drive the reaction to completion(note that I said "sodium" sulfite and not sulfite... there is about 37% error introduced between the two expressions.........I am interested in why anyone would consider introducing cold water into a boiler feedwater system absent a deaeratior or some type of pre-heater...???

 

[25362]

This is one website example (out of many others) on the use of tannins as well as sulfites as oxygen scavengers:

http://www.accepta.com/Industry_Water_Treatment/Boiler_water_oxygen_scavengers.asp

 

[davefitz]

The dearator storage tank may be more related to the required storage delay time for feeding the downsteram boiler feedpumps- if the upstream condensate pump trips the operator may need 2 minutes to start the alternate condensate pump, so the DA tank storage capacity may be defined as 3 minutes,independent of oxygen scavenging effectiveness.

For power plants that cycle - startup and shutdown once a day- the problem of flow accelerated corrosion is severe. It is related to the upsets in pH and O2 of the condensate during initial restart periods- these upsets cause the protective magnetite layer to spall off. Also, excess feed of hydrazine can also damage the magentite layer, so the minimum setpoint for O2 is 2 ppb, never less. If teh use of a catalyst can reduce this problem , it is a benefit.