Boiler starting situation

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Re: Boiler starting situation

Post by Overmod on Fri May 24, 2013 9:10 pm

If you look at the Snyder patent, he offsets the ranks of tubes, to give good free area with plenty of tube contact to the air. You could easily use vanes or webs between tubes to give flow shaping.

Potential difficulty with Nigel's pans is that the airflow enters roughly orthogonal to the pan, across the whole base area. A preheater would have to extend across all the angled vents ... and since the Snyder design relies upon multiple levels of tube, and is essentially 'linear' as designed (it goes up the gap between the mud ring and the ashpan) it would involve an awful lot of piping between the pan and the track. The alternative would be a windbox with shape giving equal airflow at all the little tubes ... gives me a bit of a headache thinking about it ... but would be relatively simple to put the heaters at an entrance duct to this box, or around as much of the perimeter as would be left open.

Makes much better sense for the Canadian-style setup, where it's almost tailor-made for the primary air, and adaptable to both types of presumptive secondary-air admission...

I'd like to see how Nigel himself would provide air preheat for one of his swirl-inducing firepans...

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Re: Boiler starting situation

Post by 1802 on Sat May 25, 2013 3:46 am

Dave

There seems to be some fundamental misunderstanding here when you said:

DaveLathrop57 wrote:The Porta McMahon program isn't practical as its requirements run contrary to FRA regulations about such things as frequency of washouts, etc. Dave

Porta Treatment's results ARE NOT a function of washout frequency. On sub 28 day wahouts in South Africa it still functioned. FCAF's 365+ days is nice to have if you can achieve it but it isn't going to be possible everywhere, well not until regulation catches up.

The treatment works (missing out a huge amount of info, of course) through the concentration and mix of chemicals in the boilers. That's all. So if you have to washout often to meet requirements then, when filling the boiler from empty, you'll find yourself adding lots of chemuical to get the chemistry right from the start. That's all.

What else is of concern in FRA regs? I can't see anything.

Martyn Bane

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Re: Boiler starting situation

Post by Overmod on Sat May 25, 2013 6:32 am

I don't like it any more than you do, but see title 49 USC part 230.60(a). (That's applicable United States law.)

[Note: for those new to the revised code: read this: http://www.steamcentral.com/archive/op0003a.shtml]

It may be possible to get a waiver for boilers using PT, perhaps with the dosing and daily/weekly test results being used instead of the washout reports to 'prove' that safe concentrations have been kept and oversight over boiler condition maintained. I would certainly advise working toward this, perhaps by directed inquiry to members of the technical advisory committee. (However, since some of those people wanted blanket legislation treating superheaters as separately-fired pressure vessels, it might be an uphill battle to get to 'common sense'). What is needed is a procedure to document adherence to the Treatment's requirements, and a simple way for FRA inspectors to confirm the chemistry quickly and easily for themselves on demand. (This would likely involve the kind of test apparatus now used for swimming pool water -- hopefully this sort of thing is already designed and marketed for use with PT; if not, it would be an appropriate part of the scope of this project to design one, even if all commercial rights stay with the Treatment principals.

As noted, transfer pumping of the boiler water (to preserve the chemical content) will also work to 'satisfy' regs, and I would expect most FRA inspectors to be 'understanding and sympathetic' to NHVRR about this particular issue once the Treatment history and capabilities are made clear to them. I think transfer is a practical alternative on a locomotive this size. (It is also an alternative when storing the locomotive for long periods of time between operations, or if it will be stored outside in freezing weather (when it would probably be imprudent to use the boiler-filled-completely method of preventing oxygen infiltration). So the costs involved producemultiple benefits for one investment...

A few of those blow-molded square containers used for carrying chemicals on farm and work trucks would happily accommodate all the boiler contents for the time it takes to pull plugs to satisfy 230.60 (b) and (c), although these probably won't let the water be kept particularly overcritical (either in temperature or pressure). Still, water at 99 C is better than water at ambient when firing up again...

As noted, I would purge and counterpressurize the container and lines with dry gas to keep O2 scavenger cost down. That should be less than the cost of 'make-up' scavenging chemical needed otherwise.

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Re: Boiler starting situation

Post by 1802 on Sat May 25, 2013 12:44 pm

Dave

Unless I am reading the wrong version it states:

"230.60 Time of washing.
(a) Frequency of washing. All boilers shall thoroughly be washed as often as the water conditions require, but not less frequently than at each 31 service day inspection. The date of the boiler wash shall be noted on the FRA Form No. 1 or FRA Form No. 3. (See appendix B of this part.) "

That is fine. 31 days is doable. If a hefty dose of chemical is added to the boiler when filling from empty the chemistry will be setup and running from the time the first fire goes in. Then at the end of day 31 washout and start again, with or without the old water. A pain in the rear if it is unnecessary but all OK from a point of view of treatment performance. The key is to have the chemistry right, not how long the steaming cycle is. I'll assume the boiler will be clean to start with but if it were not 31 days or less would be prudent at the start of the application. Shaun's 2003 paper on PT application at FCAF records they very cautiously expended washout intervals based on the internal condition of some previously very seriously scaled boilers.

I see nothing in the regs which dictates the boiler water chemistry? Or am I misunderstanding you? As such I see no reason for FRA inspectors to be involved with that side of things? My reading is they care that the paperwork is in order and that you can prove you are applying the letter and the spirit of the law.

However, to pick up your question the water condition monitoring is Total Dissolved Solids and alkalinity (normally a shortcut measuring the pH is sufficient). Both can be done with off the shelf meters. A proper measure of alkalinity is done by a rough and readt titration with indicator solutions but, generally, that is overkill.

My approach would be:

1) Make it work within the current regulatory/legal framework.
2) Make sure everyone knows it is working.
3) Run it like it for a whole boiler ticket life.
4) At the boiler overhaul get everyone in to crawl all over the boiler.
5) THEN see about changing things.

A further point - don't worry too much about oxygen in the water. Seriously.... the chemistry is such even with oxygen there no corrosion will occur. The fresh tannin coming with the feedwater will sort that out.

And another thing..... the boiler needs to have submerged water feed rather than a top feed. Top feed makes scale (any delivery trays will fill with the stuff) and it's oxygen removal is irrelevant due to the chemistry in the water.

Martyn

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Re: Boiler starting situation

Post by DaveLathrop57 on Sat May 25, 2013 12:48 pm

I'll readily concede that my previous talkis were over a decade ago in the context of an intensively run mountain railroad with proven water issues. Things have evolved since then. I'll see if I can get dave Dick to chime in with the current state of water treatment at NHVRR and perhaps that will give us a benchmark for the starting point of consideration.

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Re: Boiler starting situation

Post by 1802 on Sat May 25, 2013 4:08 pm

Any treatment regime needs to have a solution for the following concerns:

1. Fouling - scale and sludge. All sludge should be non-adherent and fully mobile.
2. Corrosion - of steel and any non-ferrous.
3. Caustic embrittlement.
4. Steam contamination - this one will floor every water treatment company you ask. They don't think about it and can't do it.

A question? What form of low water device(s) are fitted/proposed?

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Re: Boiler starting situation

Post by DaveLathrop57 on Sat May 25, 2013 4:46 pm

Our requirements are two separate water glasses - gage cocks are optional. The lowest visible point must indicate at least 3" above the top of the crown sheet. No additional devices are required.

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Re: Boiler starting situation

Post by 1802 on Sat May 25, 2013 4:54 pm

Ok, thanks. It'll never be allowed to run in the UK like that!

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Re: Boiler starting situation

Post by DaveLathrop57 on Sat May 25, 2013 5:12 pm

Invite us over and we'll see what we can arrange. We sort of rely on our firemen and engineers to watch the water closely. Apart from fusible plugs, what devices are most common over there?

Dave

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Re: Boiler starting situation

Post by 1802 on Sat May 25, 2013 6:06 pm

Fusible plugs are it. Nothing else, most plugs are lead cored but a few machines have drop plugs.

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Re: Boiler starting situation

Post by Overmod on Sat May 25, 2013 7:02 pm

1802 wrote:
I see nothing in the regs which dictates the boiler water chemistry? Or am I misunderstanding you? As such I see no reason for FRA inspectors to be involved with that side of things? My reading is they care that the paperwork is in order and that you can prove you are applying the letter and the spirit of the law.

What we are discussing is the extension of the required 31-day complete washout when it can be proved that PT is being applied (and TDS/alkalinity/scavenge documented) accurately.

I think there are two members of the ASME ESC watching this forum and hopefully one of them will advise the best way this might be taken up for ultimate Part 230 revision.

What I see likely is a documentation record of the various PT variables, taken at a reasonable interval (perhaps intermittently, on each running day) that substantiates the Treatment is in effect. These would be kept in a revised version of the current boiler maintenance documentation. FRA inspectors would give these records the same 'honor system' respect currently given for washout intervals, but of course could always test the water themselves (for instance with the method Martyn described).

My approach would be:

1) Make it work within the current regulatory/legal framework.
2) Make sure everyone knows it is working.
3) Run it like it for a whole boiler ticket life.
4) At the boiler overhaul get everyone in to crawl all over the boiler.
5) THEN see about changing things.

Common sense is always delightful.

On the other hand, I think we now have enough established 'baseline' that proves the Treatment's efficacy to have it taken up directly in the ESC. I presume that some approach has been made to the ESC to have it adopted here. Has that met with any official disapproval -- or do we need to suggest it to the right ears?

A further point - don't worry too much about oxygen in the water. Seriously.... the chemistry is such even with oxygen there no corrosion will occur. The fresh tannin coming with the feedwater will sort that out.

Doubtless this is correct -- but I would still recommend checking scavenging efficiency if for no other reason than effective due diligence. If it were me, I'd have a check on scavenging be part of the recordkeeping... but then again, I'd also make this a more stringent requirement for ordinary (non-Treated) boilers...

And another thing..... the boiler needs to have submerged water feed rather than a top feed. Top feed makes scale (any delivery trays will fill with the stuff) and it's oxygen removal is irrelevant due to the chemistry in the water.

Let's discuss exactly where the boiler feeds should be made on this locomotive, with this point in mind.
(Stupid Question: can a top feed with extended nozzles to put the feed below water level in the boiler be made to work?)

If I may make a comment here: I think the Porta Treatment (as a proprietary and for-profit system) ought to be adopted, as a means of furthering the work that Shaun, Martyn, etc. have done with respect to the subject.

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Re: Boiler starting situation

Post by 1802 on Sun May 26, 2013 5:32 am

I think my approach is based on experience in the UK and elsewhere. Easier to change something with firsthand evidence regardless of the quality or quantity of reported evidence.

Porta never tested for an oxygen scavenger, in this case tannin. A test for tannin is common enough but what level to set as the minimum? I could work something out but it goes against how the treatment works/is monitored. You could consider trying to measure dissolved oxygen in the boiler water (not likely to be so easy as once the water is out of the boiler it will absorb oxygen, carbon dioxide and so on) but also, as oxygen levels are not hugely important what would it actually prove? I would concede if that was what was required to satisfy a requirement then that is different!

I see no problem with top feed with internal delivery pipes to put the feedwater where it is wanted. I considered it with a loco here in the UK which has delivery trays. When the loco was stopped for overhaul we found the trays were rammed full of scale. Of interest is that, other than on the GWR, top feed trays were done away with for this very reason. Top feed remained but instead of trays directional plates/vanes were installed at steep angles. None the less, at least in theory, top feed - where the feedwater passes through the steam - will create more scale in the boiler water. In reality the treatment will dissolve most of it but it won't dissolve the lot as some scale is insoluble.

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Re: Boiler starting situation

Post by JJG Koopmans on Sun May 26, 2013 9:33 am

Imho we are thinking on 2 different paths. In the case of the superheater the argument against is the lenght of the road while for water treatment it appears not to be so. On board water treatment is for locomotives which cannot rely on their water source. If you can, a fixed water treatment plant is to be preferred, dumping all kind of chemicals in your boiler is only second best
Sorry for treading on toes!
Regards
Jos

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Re: Boiler starting situation

Post by DaveLathrop57 on Sun May 26, 2013 10:11 am

Given we don't know what the water is like or what treatment is being used, but we do know 17 is doing fine under whatever regimen is in place, deciding on anyparticular treatment program is probably going to need to wait for better information. No reason we can't talk about the Porta McMahon treatment program and how it works relatie to other more traditional programs.

Many of our younger steam people (and some of the older ones as well) at NHVRR know nothing about it.

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Re: Boiler starting situation

Post by 1802 on Sun May 26, 2013 1:29 pm

Jos

“dumping all kind of chemicals in your boiler is only second best”

A sweeping statement which dismisses 80+ years of internal treatments in one line; to be taken seriously you will need to justify your statement and in a technical manner. If it was me I’d have a very thick list of references to hand ready to quote from and which are relevant to locomotive firetube boilers remembering the often much higher rates of evaporation per unit of surface area than industrial firetube or watertube boilers.

Martyn

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Re: Boiler starting situation

Post by DaveLathrop57 on Sun May 26, 2013 2:57 pm

A couple things: I think Jos meant that any chemical treatment should be based on measurable conditions within the water and boiler, not that the use of all chemicals under all circumstances was bad. If I'm wrong I apoligies.

And, the Porta system is supposed to work without having to add a lot of chemistry to the boiler if I'm remembering correctly.....unless that's changed in the past 10-12 years. The idea was to run without doing frequent washouts or treating the boiler with the traditional agents (apart from antifoam). What we were discussing way back when was doing washouts and replacing the Porta-cized water back into the boiler after settling out the solids to comply with the regulated minimum washout schedule requirements. Then we got into the matter of whether or not the sludge settled off was hazardous and had special disposal issues.....

Can't recall much ore about how it ended up, other than the investment into the infrastructire didn't interest my boss. He figured that monthly washouts were cheap enough and allowed us to rotate power on a 30 day basis for mechanical maintenance as well.

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Re: Boiler starting situation

Post by JJG Koopmans on Sun May 26, 2013 3:04 pm

Hi Martyn,
I do not want to dismiss 80 years of experience with on board treatment. My point being that there is a difference between a small railway line with one source of water and a railway network with all kinds of dubious water qualities. The single water source is better off with a small treatment plant to supply perfect water for steaming while the network is better served with onboard equipment. After all, how young is reverse osmosis!
Kind regards
Jos

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Re: Boiler starting situation

Post by 1802 on Sun May 26, 2013 3:34 pm

Please justify, so far I only see opinion.........

The "after treatment" needed to make RO water suitable for boiling in loco boilers leads to significant steam contamination. How does one fix that problem? (Refs: "GE Handbook of Industrial Water Treatment", Hamer, Jackson & Thurston "Industrial Water Treatment Practice", Porta, LD "Advanced Steam Engine Tribology" 1995)

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Re: Boiler starting situation

Post by Overmod on Sun May 26, 2013 3:46 pm

Dave, I think you are referring more to the TIA style of water conditioning. If I remember correctly, one of the salient points of Shaun's development of PT was to have excess TDS of the right kind in the boiler to keep the sludge -- including any newly-developing sludge tendency -- mobilized. That is a very different thing from 'purifying' the water of anything that might cause sludging in the first place.

My opinion is that having a treatment plant for water is an extra expense; what would it be? Zeolite exchange (with required salting expense)? Some form of RO?

Sure, I'd run the feedwater through some sort of filter iif going into a holding tank, perhaps even use a cheap flocculant on it -- but not dose it in the tank and have to deal with precipitation there. Meanwhile ...

... you're still going to need active chemistry against corrosion, whether that's done with tannins or some active deoxygenator. And you will probably want at least some dose of antifoam for running, even if you are not concerned with DS. So why not just centralize the dosing so it is all done in the locomotive tank, based on how much water is run in there first?

I firmly come down on the side of using available water, then dosing to correct numbers right on the locomotive. Even for small railroads with only one or two engines, run intermittently. That cures any problem if the source of feedwater is changed, or its quality changes, or having to deal with who has to run and service the water plant, or if there are storage problems with the stationary treated feedwater. Even at for-profit margins, you'll buy a lot of chemicals with the expense of a RO setup of sufficient size ... and the last time I looked, the service life of the RO membranes was limited if the water supply was chlorinated or ozonated...

No, the settled sludge is not hazardous. Whether there are some puzzle-palace-originated ukases that claim it is, that's another story. I would suspect there might be a market for at least some components of the sludge ... if you had a sufficient volume of it to matter.

Martyn -- I mentioned oxygen testing as it might be something that favors long-term delay of washing out. I don't think there is any great difficulty in testing oxygen content without admitting atmospheric oxygen -- been done in powerplants for dog years. It would also be relatively easy to test for dissolved iron salts and other evidence of corrosion periodically, to ensure that the Treatment is doing its thing. Yes, I believe an excess of tannin would solve the question... but wasn't there some argument about Porta or Shaun wanting to use a better chemical than tannin in some applications of the Treatment?

I do think the very important issue of steam contamination needs to be addressed, perhaps in its own little subthread. I am more concerned with water carryover than with any contaminant carryover in the steam for something this size, and perhaps that becomes more 'possible' using the Treatment if the antifoam is not carefully monitored and religiously adjusted -- but I have already indicated elsewhere that better methods of steam separation may solve the issue before it gets difficult in the first place.


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Re: Boiler starting situation

Post by JJG Koopmans on Sun May 26, 2013 4:21 pm

Hi Martin,
Nothing is perfect and of course there are biased opinions towards other ways of treatment. All I am aware of is that the heritage organisations in the Netherlands use RO, are satisfied and can prove why.
Kind regards
Jos

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Re: Boiler starting situation

Post by 1802 on Mon May 27, 2013 12:06 pm

Overmod wrote:My opinion is that having a treatment plant for water is an extra expense; what would it be? Zeolite exchange (with required salting expense)? Some form of RO?

Not come across RO plants without a softener of some flavour being used to condition the water first. If you don't pre-soften you risk clogging the membranes.

Overmod wrote:... you're still going to need active chemistry against corrosion, whether that's done with tannins or some active deoxygenator

No, sufficient alkalinity in the water deals with corrosion. I grant you this is a much missed/misunderstood point! Refs:

Gray, J.A.: "Boiler Water Treatment: A Formula for the Control of Sludge and Scale in Internal (Carbonate) Treatment". Journal of the Institute of. Fuel. Vol.: 30. 1957.
Thurston, E.F. and Furnival, L.: "Boiler Water Treatment: A Formula for the Control of Sludge and Scale in Internal Carbonate Treatment: Experiments in Laboratory Boiler". Journal of the Institute of. Fuel. Vol.:30. 1957.

Overmod wrote:And you will probably want at least some dose of antifoam for running, even if you are not concerned with DS.

Above about 600ppm steam contamination becomes significant. However, antifoams which can produce "pure steam" (only measured to 2ppm threshold so far. The actual contamination could be 1.9ppm or anywhere between there and 0ppm) only start to do their job above 6000ppm and when certain other factors are present. Refs:

GE Technology: “Handbook of Industrial Water Treatment”.
Porta, L.D.: “Comments on the article – Die Speisewasser Innenaufbereitung bei den Damplokomotiven der Deutschen Bundesbahn written by J.Robrade in Eisenbahntechnische Rundschau Mai 1956, 183-190”. 1984.
Porta L.D.: "Advanced Steam Engine Tribology". 1995

Overmod wrote:No, the settled sludge is not hazardous. Whether there are some puzzle-palace-originated ukases that claim it is, that's another story.

Constituents are going to determined by water source but essentially you are looking at a compounds of calcium, magnesium, silica and small amounts of other stuff. Nothing to be worried about there unless there is a common sense failure.

Overmod wrote: wasn't there some argument about Porta or Shaun wanting to use a better chemical than tannin in some applications of the Treatment?

Not that I am aware of. Quebracho does multiple things/has too many benefits to replace it with something else.

Overmod wrote: I am more concerned with water carryover than with any contaminant carryover in the steam for something this size, and perhaps that becomes more 'possible' using the Treatment if the antifoam is not carefully monitored and religiously adjusted -- but I have already indicated elsewhere that better methods of steam separation may solve the issue before it gets difficult in the first place.

Water and solids go hand in hand. Cure one and you cure the other. Antifoam is in the standard treatment mix. As long as the treatment goes in so does the antifoam. Remember it was developed for then fleet used in NW Argentina where, at the time, few of the shed staff could read or write and the level of technical ability was sometimes limited to hammers and bigger hammers. It survived there so.....

If you can get pure steam at the throttle valve through the action of the water treatment why subject the steam to pressure loss by passing it through an unnecessary separator? I shouldn't worry about small steam space. Having seen what was achieved at FCAF (round top boilers, very small steam spaces) and know some of the details of the testing to destruction carried out by Porta there will be no problems.

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Re: Boiler starting situation

Post by Overmod on Mon May 27, 2013 2:15 pm

Snipped without prejudice to the other items discussed.

1802 wrote:
Overmod wrote:... you're still going to need active chemistry against corrosion, whether that's done with tannins or some active deoxygenator

No, sufficient alkalinity in the water deals with corrosion. I grant you this is a much missed/misunderstood point! Refs:

Gray, J.A.: "Boiler Water Treatment: A Formula for the Control of Sludge and Scale in Internal (Carbonate) Treatment". Journal of the Institute of. Fuel. Vol.: 30. 1957.
Thurston, E.F. and Furnival, L.: "Boiler Water Treatment: A Formula for the Control of Sludge and Scale in Internal Carbonate Treatment: Experiments in Laboratory Boiler". Journal of the Institute of. Fuel. Vol.:30. 1957.

In my opinion, this specific point, with references, should be presented to the ASME ESC when discussing washout intervals and required testing modalities for US use of the Treatment. If I understand correctly, an adequate 'substitute' for dissolved oxygen concerns is provided by jointly assuring an adequate quantity of tannins and the right level of alkalinity (for the range of temperatures and pressures seen even in higher-pressure staybolted locomotive boilers). I believe this is a valid and significant point for other operations. Correct me if this is wrong, or if more variables would need to be monitored to assure corrosion control.

I strongly suspect that some method of providing alkalinity that does not lead to increased corrosion in cracks and under scale should be used (I believe I have references but would have to look them up in 'dead storage')

1802 wrote:
Overmod wrote:And you will probably want at least some dose of antifoam for running, even if you are not concerned with DS.

Above about 600ppm steam contamination becomes significant. However, antifoams which can produce "pure steam" (only measured to 2ppm threshold so far. The actual contamination could be 1.9ppm or anywhere between there and 0ppm) only start to do their job above 6000ppm and when certain other factors are present. Refs:

GE Technology: “Handbook of Industrial Water Treatment”.
Porta, L.D.: “Comments on the article – Die Speisewasser Innenaufbereitung bei den Damplokomotiven der Deutschen Bundesbahn written by J.Robrade in Eisenbahntechnische Rundschau Mai 1956, 183-190”. 1984.
Porta L.D.: "Advanced Steam Engine Tribology". 1995

I was referring more to the desirability of being able to vary the antifoam dosing directly on the locomotive, perhaps on an ad hoc basis, rather than relying on antifoam concentration determined at a central water-treatment location. I also thought that there might be operating or transient conditions that lead to increased, unanticipated priming or other situation that would benefit from directly-available supplemental antifoam administration. (This is a lesser concern at the temperature/pressure 110 uses.)

1802 wrote:
Overmod wrote: I am more concerned with water carryover than with any contaminant carryover in the steam for something this size, and perhaps that becomes more 'possible' using the Treatment if the antifoam is not carefully monitored and religiously adjusted -- but I have already indicated elsewhere that better methods of steam separation may solve the issue before it gets difficult in the first place.

Water and solids go hand in hand. Cure one and you cure the other. Antifoam is in the standard treatment mix. As long as the treatment goes in so does the antifoam. Remember it was developed for then fleet used in NW Argentina where, at the time, few of the shed staff could read or write and the level of technical ability was sometimes limited to hammers and bigger hammers. It survived there so.....

If you can get pure steam at the throttle valve through the action of the water treatment why subject the steam to pressure loss by passing it through an unnecessary separator? I shouldn't worry about small steam space. Having seen what was achieved at FCAF (round top boilers, very small steam spaces) and know some of the details of the testing to destruction carried out by Porta there will be no problems.

I was proceeding on the basis that the antifoam was consumed over time whereas the 'mobile sludge' TDS remained until blowdown; Shaun specifically noted that the higher TDS would greatly increase priming effects if adequate antifoam was not maintained. What I was addressing included the situation where the Treatment would be in use but for some reason a dose of the antifoam was missed, or insufficient, or the wrong chemical administered (unlikely, but I have a glutaraldehyde story to tell you... ;-} ). Under such conditions, having a mechanical backup ought to be beneficial.

I had thought that providing a mechanical (electrically-driven) separator would pose a relatively low impediment to steam flow -- but of course it can be designed (with some care) so it could be installed and removed simply and with relatively little modification, so even if designed 'early' it need not be constructed or installed until a need is actually perceived or demonstrated.

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Re: Boiler starting situation

Post by Overmod on Tue May 28, 2013 10:06 am

1802 wrote:
Overmod wrote:In my opinion, this specific point, with references, should be presented to the ASME ESC when discussing washout intervals and required testing modalities for US use of the Treatment. If I understand correctly, an adequate 'substitute' for dissolved oxygen concerns is provided by jointly assuring an adequate quantity of tannins and the right level of alkalinity (for the range of temperatures and pressures seen even in higher-pressure staybolted locomotive boilers). I believe this is a valid and significant point for other operations. Correct me if this is wrong, or if more variables would need to be monitored to assure corrosion control.

That's all fine if you think getting some change is achievable, excuse my ignorance of the US situation, but how realistic is arranging a change from the norm?

Extremely.

Since the advent of a liaison between the ESC and FRA, amending and redacting USC 49 part 230 has become much more straightforward. The key (as far asi I am concerned) it showing common-sense ways to document safe procedure for practical applications, backed up by simple test modalities that FRA inspectors can use, and showing the references in the literature and in reproduceable experimentation that indicate how the Treatment accomplishes what is claimed. I believe most of this already exists in mature form, and the remaining details need only to be framed 'correctly' before taking the issue up with the ESC (whose membership, again, is known, and several members of which are likely at some point to be following events on this forum).

Martyn -- please recapitulate what has been done, in detail, to get the Treatment accepted as 'legal' in the United States so far?


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Re: Boiler starting situation

Post by 1802 on Thu May 30, 2013 6:16 pm

1802 wrote:Porta makes mention of some steam era separator in one of his papers to be used under certain conditions as a backup/fall back in the event of certain factors. All the details escape my memory at this point. I'll see if I can find the details. Whatever it is will almost certainly be in one of the later volumes of Locomotive Cyclopedia, at a guess I'd say 1947 as this is the issue Porta had. This week is about to get very busy so I won't get chance to search out the reference for a while.

Right, found the ref. To quote Porta:

"Elesco moisture separator as a safeguard against mishandling of the water level"

This comes from a paper listing mods possible but not necessarily required/only required in certain contexts/applications.

You could add a foam height meter as a warning device, I'd say it would be preferable to a separator.

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Re: Boiler starting situation

Post by Overmod on Thu May 30, 2013 7:37 pm

We had a discussion about that Elesco 'steam dryer' on steam_tech a few months ago, in connection I believe with a Canadian 4-8-2 equipped with the device.

I, personally, think it is about as valuable as drop plugs in a modern American wide firebox, which is to say not very. Both these approaches seem to think that the water level in the boiler is ... well, a level. It is not, and particularly not when priming or surging sufficient to justify use of a passive separator is occurring.

As designed, the Elesco device routed the separated water back into the boiler. How much of it actually got there without re-entrainment in the dry pipe steam is something of an open question; the Canadians, among others, fixed the situation by routing the separated water entirely out of the boiler without even attempting to economize.

In this particular case, I would question whether an adequate device can be fitted within the confines of 110's steam dome. We recently had someone complain that an active separator would block the steam path too much; how much greater the blockage from a great hunk of cast metal sitting up there.

It is possible that an Elesco dryer would work, but I would cut straight to an active device that actually provides positive separation to the water droplets and carryover... seeing as we will have electrical power on the locomotive to run such a device.

The Foam-Meter is an interesting device... but why is it any better than the N&W Christmas-Tree approach (where you hang a few spark plugs at defined heights and measure across the gaps to see if something more conductive is there...)? Seems to me easy enough to develop a simple 'prime' light that changes color with severity. With simple, OTS devices already rated for the level of pressure they will experience threaded into bungs or whatever...

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Re: Boiler starting situation

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