thank you for getting back. The green color is not slime at all nor do i think that its algea, its like green cool laid (got to love the reference). The green color has been there before the asphault (probably from some sort of water treatment). I also failed to mention that they blowdown into a pit that is filled with water due to a clog in the drain. Maybe algea is growing in the tank hmmmmm. Well thank you for your info here its something we have to address to prevent the damage to the asphault.
i notice that it leaves puddles of green.
Probably from all of the pine pollen. I wouldn't worry unless it makes you sneeze.
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Interesting concern.
The blowdown is mostly just hot water and disolved minerals which by the time it hits the ground would be no hotter than the sun would make the asphalt so I doubt if the heat is a problem and the minerals are probably what the rocks in the asphalt are made of, so I see little to be concerned about there.
There maybe other chemicals added to the water to reduce foaming and prevent hardening of the precipitates in the the boiler (soda or Lye, as mentioned above, and which is used depends on the type of the hardness in the water that is being used), that might be of concern. I would GUESS that maybe Lye might be a problem, but a chemist would need to chime in here to state yes or no and why.
The green color could be from the boiler water treatment, but could also be the result of the water just lifting the residual light oils from the asphalt and imparting a green cast to the surface of the puddles. Kind'a depends on what you mean by "puddles of green"... green slime or algae (it would not be algae from inside the boiler... no sunlight and it'd be boiled algae, too!) or just a shimmer of green on the surface.
Semper Vaporo
Pkgs.
hello there,
I know nothing of trains, dont get me wrong i think they are great! i work in a wood shop at a theme park and we have a train that blows down in our area. we just got new asphault done in the area because the old asphault was well gone. My question is, when the train blows down is the steam and liquid generated corrosive? i notice that it leaves puddles of green. I was just wondering if there should be a concern for the new asphault.
dldance wrote: As the previously posted pictures show - the blowdown packs a lot of force. Today in the May 10th commemoration at Golden Spike, the blowdown snapped a Tee in the blowdown line. That is schedule 80 pipe.dd
As the previously posted pictures show - the blowdown packs a lot of force. Today in the May 10th commemoration at Golden Spike, the blowdown snapped a Tee in the blowdown line. That is schedule 80 pipe.
dd
cprted wrote:This is what it looks like. Also makes one heck of a racket.
dldance: Thanks for the reminder of the name of the bottom the boiler around the firebox, it had completely escaped the ol' brainbox. Mudring is quite descriptive of what collects in it.
cprted: Thanks for the photo. It reminds of a couple of years ago at the Midwest Old Settler's and Thresher's Reunion in Mt. Pleasant, Iowa. They have a narrowguage RR around the grounds and run 3 different types of steam locomotives. When they need to blowdown the boilers it is usually at a curve where there is a bit of a gully (that keeps the people away) near where the yard of the shop is (where few patrons tend to go, for some odd reason). The train is still blocking a walkway/road when they do this (the engine is about 100 ft away from the road and the side of the engine is toward this gully and the shop yard, aimed well away from where people are).
I like to watch people when the blowdown occurs. Jaws usually drop and worried glances are exchanged. The incident a couple of years ago was at one of these blowdowns... an elderly (I guess I better be careful what I call elderly!) lady gasped quite loudly and went 'stiff' as the blowdown began. She then kind'a gushed something like, "Is it blowing up?" I was standing near and basically told her what I described above, (only I got to wave my hands around in the air a lot more).
She said that she had grown up along side a steam railroad and had ridden many steam trains and had never seen it before. She then thanked me for the explanation and walked away. I then turned to leave and realized I had given a lecture to about a dozen people who listened in on it, and two had videotaped it!!! I wish they would post the video to YouTube.
nicknoyes wrote: Thank you Semper Vaporo for the answer to my question. David Morgan did mention that there was an, "abundant supply of soda used to keep the hard stuff from forming". Now I understand. Thank you. I mentioned page 97 in my question. It is actually on page 89, left hand column. Nick
Thank you Semper Vaporo for the answer to my question. David Morgan did mention that there was an, "abundant supply of soda used to keep the hard stuff from forming". Now I understand. Thank you.
I mentioned page 97 in my question. It is actually on page 89, left hand column.
Nick
with our water - we use lye not soda. We also use a de-oxygenator to forstall the corrosion problem that sidelined UP844.
Also thanks to Didance for the interesting description and further info.
The water sides of the firebox are also known as the 'mud ring' because that's where the percipitates collect. On the steam engines at Promontory the blowdown shoots water out about 15 - 20 feet to the side of the engine. We don't have foaming problems with the water there so I only blow down a couple of times. It is generally done early on the first run of the day before movement and internal boiler water circulation stir up the mud. That is also when the boiler has the most water in it - so the blowdown doesn't drop the water level too much.
In addition, every 30 days, the fire is dropped, the boiler is let cool and the boiler is drained and flushed. We use a mix of high pressure air and water to blow as much mud out of the boiler as possible.
When water is boiled and turned into steam, only the pure H2O leaves the boiler. But "water" is seldom pure H2O. It usually has other compounds disolved in it. Most commonly it is elements we usually associate with "rocks" (calcium, etc.). Elements that are gases escape with the steam, but the heavier elements stay in the boiler. Eventually, these elements become so concentrated that they precipitate from the water and form a scale on the insides of the boiler.
Besides taking up space in the boiler, high concentrations of this material tends to make the water produce foam and that foam can get "carried over" into the the cylinders. The foam is mainly "water" and can fill the cylinder such that there is more water in the cylinder than there is space available when the piston is at the end of its travel. Water does not compress so something then has to give as the piston approaches the end its travel. The piston rod can bend or the end cap of the cylinder can be "blasted" off the end. Either situation tends to ruin the day of the train crew and the Road Foreman of Engines.
But the main problem is that this scale is an insulator and separates the water from the source of heat. The reason the boiler material does not melt in the presence of the fire is that the water takes the heat away as steam. If there is insulation between the fire and the water, the metal of the boiler can soften and melt. This can also tend to ruin a man's life... abruptly; it is known as a boiler explosion.
There are valves placed low in the water space, usually along the outside of the water space of the sides of the firebox, that can be opened to allow the water to escape (quite violently) and in that process it takes some of the sediment with it. It also reduces the amount of water in the boiler and that MUST be replenished with more water. In that process, the concentration of impurities in the water goes down on the whole (less water in the boiler that has a high concentration of impurities, plus more water that has less impurities) and so less material is available to precipitate out and collect on the boiler interior.
Chemicals can be added to the water that help keep this material from sticking to the metal of the boiler and reduce the tendency to foam, but you still need to remove the "rocks" periodically. How often depends on the amount of "non-water" in the water and how much steam is taken from the boiler.
In the last chapter of the Kalmbach Special Collectors Edition, In Search of Steam, David P. Morgan describes the fireman's job on a Wabash Mogul steam engine. One of several jobs he mentioned was blowing down the boiler. Morgan states, "- - - in the first 6 miles to Meredosia both engines were blown down at least four times" Why is it necessary to "blow down " the boiler and how is this done?
By the way, In Search of Steam 1953 - 1954 is a great collection of articles well written and very interesting. My question comes from page 97, left hand column.
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