I am reaching out to all of you Steam experts to help me answer a few questions that I can't find answers to either on this forum or the larger internet
My knowledge of steam is limited to boiling a kettle, but have taken the plunge and bought a Microcosm M30 steam plant as shown and a 49-inch glass fibre hull to make a Thames launch-style boat.
My questions are as follows.
Tap water, ionised water or pond water and water tanks.
- I have read some conflicting information about the use of tap water (scaling the boiler for example) but what about pond water after all there is plenty of it when running the boat! If it looks clean can it be used, perhaps running it through a paper filter first?
- I can see the advantage of a separate water tank versus filling the boiler directly, but can the boiler be topped up while it is still hot, then what about the pressure inside the boiler would a hand pump overcome the pressure or would an automatic/electric pump be better?
- I have seen water tanks being formed in the bow of the boat, which seems like a good use of space. Do the tanks need venting to let air in? Do you need to fit a stop cock between a hand pump and boiler or are the hand pumps good enough to withstand boiler pressure?
Gas tanks
- Can gas tanks be lagged (for cosmetic reasons) like the boiler or is it best to leave it as is?
- Is it advisable/sensible that gas tanks should be filled outside the boat?
- Should a gas regulator/cutoff be fitted in case you need to turn off the boiler remotely - if so what are the options?
Condensor tank
- Same question as the gas tank - is it OK to lag?
- Can I exit the steam into the boiler chimney, or is it best to leave a pipe running up the side of the chimney?
Electronics
- I see it is possible to fit pressure sensors, water level sensors, ECU, GCU etc - would any or all of these be useful/desirable?
- Are there any telemetry options that could signal any potential issues to the transmitter?
No doubt will have other questions after I get the engine and boiler
Thanks.
You have the same boiler, burner and gastank as me, but a slightly different engine. I am not familiar with the steam requirement of your engine, so while I am 100% positive the burner and boiler can supply the engine, I do not know what consumption will actually be, because apart from your throttle hand, the engine determines steam, and thus fuel consumption.
I know this: the boiler is good up to about 3 or 3,5 bar. The burner in stock form (without possibly limiting stuff like rgulators) can handle that as well.
There is no real problem there.
In general: Small high revving props give high steam consumption, larger slower revving props (suppressed RPM) reduce steam consumption. More or less.
The boiler can hold about 350 ml of water, and until bottom of level glass, contains about 200 ml usable water (I do not recommend running below visible water level, even if some say it is not as dangerous as people think.
My M29 engine goes through this amount of water in about 15 minutes if I take it easy on the throttle. Your engine seems to be marginally larger.
The gastank however can without issues hold about 65 grammes of fuel which is good for about 60 minutes of operation.
So IMHO, a feedpump in order to extend operating time is a must (10 minutes is not very much to enjoy your boatride, no?), and 350 to 500 ml would be a good size, it would provide about half an hour of feedwater supply, plus another 10 minutes on the water stored in the boiler.
40 minutes should be a good runtime.
Buy a small scale, and weigh your empty and filled fuel tank, experiment a bit and figure out the safe fuel level.
About the water quality: Although I know some people feed their boilers from the lake, and acknowledging that most people run the plant only a few times per year which makes scale deposits etc etc not a real problem, the engineer in me refuses to recommend that option, simply because I have no idea of the water hardness in your locale.
Better to either buy demi or destilled water (Destilled has preference over demi, but both are usable) for the sole reason that at least water quality is a known and constant parameter.
I steam A LOT, so I decided to buy me a water destiller. They are very affordable from China. The VEVOR branded destiller I bought, I saw it as low as 75 Euro at some outlets, water quality is excellent, and maintenance is virtually zero if you don't run it down to its automatic stop.
I run mine at times of low electricity rates, and it is basically free because the darn thing heats my living room on its own, meaning the central heating does not have to burn any gas
Besides, plenty folks seem to think distilled water is healthier to drink and keeps applyances like coffeemakers in better condition, so it might be a consideration in general.
But forget that rubbish if you want, you can buy demiwater, or even destilled water usually at DIY stores for reasonable prices.
For gas: Best to use LPG (propane/butane mix at 30% propane), because Butane only works properly in warmer climates or you'll need heating on the gastank.
You do NOT want the gastank lagged or clad: It contains fuel in liquid form, but the burner needs gas. As in: "evaporated". That evaporation takes place in the tank. Evaporation NEEDS heat, and you want that heat (from ambient) to have easy access to the tank, otherwise the temperature drops and pressure with that.
Now that we are talking gastank: your tank really has a safe max filling of about 65 grammes, doe NOT overfill! That is dangerous.
Especially at a just filled tank: Make sure that the boat is static and has come to rest before opening the valve on the tank and lighting the burner.
Do NOT, repeat NOT "shake" the model when the burner is on, because you do NOT want any liquid fuel entering the gasline to the burner.
It will kill the flame with an overdose of fuel, and the evaporated fuel is heavier than air. It will remain in the boat, any attempt at relighting will cause a fireball and probably loose parts flying around.
Also, ignition is a two-handed operation: hold a burning lighter at the end of the funnel, then open the gasvalve.
NEVER first open the gasvalve to then go and get your lighter.... Same result.
A gas attenuator (boiler pressure control) is ALWAYS a good thing, it makes for a much more consistent engine run, and prevents blowing safety valves or wasting gas and water. Which type, is up to you. If you're a processcontrol nutter like me, have at it with all kinds of sensors and stuff, if not, buy an analog one like the Microcosm P5.
In general, telemetry is useless if you do not know what to do with the information, but of absolutely GREAT value if you do.
Lots of things can e alarmed in many different ways, and it totally depends on what kind of sensors are availlable for your particular set-up, I can't comment on that any more detailed.
Feedwater pumps rob engine power, so you can opt for an electric one on manual control, automated control (User "rhavrane" in the past posted quite a bit of useful info on that subject).
Personally, I linked my boiler feed to the steam throttle, works also.
Basically, you need to have SOME form of feedwatercontrol, because an empty boiler is useless, but an overfilled boiler also is spoiling a lot of fun, but a crudely adjustable pump at constant speed, approximating your particular feedwater consumption allready works pretty good for a lot of people
Feedwater preheating is not necessary, but saves between 5 and 10% fuel consumption. Talking about Alarms: IF you have a feedwater preheater, a temperature alarm will reliably warn you for a malfunctioning feedwaterpump.
The "condenser" is actually an oil separator, can best be lagged, minimizing heatloss extends operation time. Without measures, mine is full in about 15~20 minutes, and once it is full, oil will be blown out, leading to spots on the pond. Lagging it extended that to about 30 minutes, but I modified mine to automatically discharge to a dirt receptacle. the receptacle is much easier to empty than the separator (no need to cool down or depressurize anything) but most important, I value an absolute non-polluting operation. Not because I am an environmentalist (I am not) but because of clubs keeping their licenses and ponds and such. It just makes life easier if people are NOT nagging about your hobby
The standard displacement oiler IMHO is rubbish. It overlubricates IMHO, and does not hold much oil to begin with. I bought the one with glass body from Microcosm. Fits right in, is fairly decent in its adjustment (takes quite a bit of trial and error, but once set is fairly stable) and holds enough oil for about 3 hrs of operation. Don't get me wrong, you don't NEED that kind of operating time, but refilling is a messy job, and having a larger lubricator means you can do multiple runs without getting dirty hands, AND you can see whether you need to refill or not.
You can lubricate the rest of the engine (rods, crossheads and excenters) manually, but that is messy, and needs to be done frequently. There are zero problems with manual lubrication. However, my advise would be to make a wickfeed lubricator for that. Fill at the beginning of the day, empty it when packing up, and no mess or attention needed.
Whatever you do, whichever method you pick, the engine WILL make an oily mess. No way around that. So build your boat with that in mind. Make sure the woodwork of the floorplate under the engine is PROPERLY treated with a good PolyUrethane laquer or something like that.
If you can make a metal tray (save-all or coaming) under the engine, that is greatly advised. Oil soaked wood weakens, deteriorates and becomes unrepairable.
Personally, I pad all the free floor plating around the engine with wads of toiletpaper or kitchen tissue that I replace at the end of the day. Keeps the boat in good shape even if I do say so myself.
In general: your first installation, get to know it with everything visible and accessible, so play with it on the testbench. Make sure you're familiar with it before installing it in the boat.
Keep that visibility and accessibility in mind when building the boat around it. Sounds like "Duh!", but you wouldn't be the first finding out something important is poorly accessible or visible that he hadn't thought about beforehand, and yes, that includes me (my feedwater valve is very poorly accessible, and you need to close that valve after killing the fire, or the vacuum will draw the entire feedwatertank into the boiler...).
All in all, steaming is good fun! It requires attention and observation when starting up, when shutting down, AND DURING sailing, and personally, I like that very much. Every succesful run on the pond is an achievement of sorts.
Good luck!
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Topic: Complete beginner to steam has steam plant question for Thames launch project (Read 4155 times)