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Re: Steam engine from the North Caucasus

Posted: Sun Sep 13, 2020 11:47 pm
by Freezerrr12
Dear Steam Engine Enthusiasts. I am very sorry that I did not receive any advice from any of you on choosing a steam boiler, but I still hope for your help. I found about 48 meters of copper tubing (155 feet) with a diameter of 18 mm. (about 3/4 inch) with a wall thickness of 1.3 mm. I ask you to answer my question: is it possible to use such pipes in a steam boiler with two pipes to achieve a pressure of 120-140 psi? Will there be enough steam from such a boiler to operate a steam engine? I am guessing that the weight of such a boiler, with two tubes 8 "in diameter and 3 feet long, would be less than 400 pounds. I am attaching a photo of the flywheel, which I was allowed to carve on a lathe last winter. Its diameter is 14 inches, and it weighs about 55 kg. Can you advise me on how to improve its design?

Re: Steam engine from the North Caucasus

Posted: Mon Sep 14, 2020 1:56 am
by TahoeSteam
Hello, I think the quantity of copper tubing you are talking about would only get you about 30 square feet of heating surface. You need almost twice as many feet of heating surface for an engine of your size. Watertubes are a good choice for speed in steaming and lightweight construction.

Re: Steam engine from the North Caucasus

Posted: Tue Sep 15, 2020 3:34 pm
by cyberbadger
The rough estimation of Boiler Horsepower is 10 square feet of heating surface = 1 boiler horsepower.

I have a 6 Horsepower Toledo Steam engine on Nyitra coupled with a boiler that has the following specs:
200psi MAWP
72 sq ft of heating surface
362 lbs/hr (ASME calculation)

For me this seems to be a pretty good match.

-CB

Re: Steam engine from the North Caucasus

Posted: Tue Sep 15, 2020 9:14 pm
by Freezerrr12
Dear TahoeSteam and CyberBadger, thanks for your recommendations. I am aware that I do not have enough copper pipes with a diameter of 18 mm. In the construction of a steam boiler, they will be able to provide an insufficient area for steam generation. But I live in a place where it is simply impossible to buy the required number of copper pipes for a steam boiler. They sent me an answer from a large plant near Moscow that they are fulfilling orders for rolled pipes from 2-2.5 tons or more. I cannot buy 2 tons of copper or even steel pipes with a diameter of 18 to 30 mm. For a boiler, I will need no more than 40-50 kg (100-110 lb) copper tubing or 70-90 kg (200 lb) steel tubing. But I thought I could run my steam engine at low rpms and low power on such a small boiler, which could deliver 60-80 psi of steam pressure up to 90 kg (200 lb). Then, two years later, I will probably build a second small boiler, with the same parameters. Even two such boilers will have less weight than one Scottish steam boiler. Much less welding is required. Is there any information on whether any American and British enthusiast built a steam boat with two small boilers? how difficult can it be? I thank you for the advice I received.

Re: Steam engine from the North Caucasus

Posted: Tue Sep 15, 2020 9:35 pm
by Freezerrr12
I also want to get information about why square holes (ports) were made in the flywheels on steam machines around the perimeter. I think that it was much easier to drill round holes, if they served, to love the crankshaft. I don't know what the correct flywheel design should be in this case. I want it to look like the 19th century. I also sent a photo of the crossheads, which will have a bronze sole (side) for proper gliding. I am currently making these bronze soles (sides) for kreikopf. Several photos on this topic.

Re: Steam engine from the North Caucasus

Posted: Wed Sep 16, 2020 1:11 am
by RNoe
The square or round holes in flywheels are for inserting a bar to rotate the steam engine as needed.
Drilling round holes in your flywheel probably is not necessary, but it will lighten it, which may be a good idea.
RussN

Re: Steam engine from the North Caucasus

Posted: Wed Sep 16, 2020 5:55 pm
by DetroiTug
Two boilers will work, they would need to be handled equally, same firing etc. If one were to be unfired no fire it would need to be isolated from the system as it would act as a condenser. Of course, if they share the same fire box that wouldn't be a problem.

A rough general idea on boiler design and steam generation, assuming a wood fire and no induced air draft, stack blower or exhaust up stack

Firetube boilers = 10 square feet of heated surface per horsepower
Water tube boilers = 5 square feet of heated surface per horsepower
Monotube and flash type boilers = 2 square feet of heated surface per horsepower

These are only rough approximations based on historical evidence from these types and their performance. There are many things involving design and conditions that can move these numbers higher or lower.

In that list, the firetube is going to be the heaviest, most costly to construct, however the easiest to control. Excellent for varying demand

The water tube types are much lighter, cost can be lower depending on the grade of tubing selected. They are fast steam generators as evidenced by their output per square feet, this also requires manual tending to be much more frequent. Depending on the design, they can be more complicated to build involving fixtures or machinery to wind or bend tubing. Welding water tube boilers is generally more difficult as weld joints are not as accessible as those on a firetube. Good tolerance to varying demand.

Monotube boilers can as simple as a coil of tubing with a feedpump on one end and a throttle valve on the other. The cost and ease of construction can be derived from that. They are very high output boilers in relation to their size and manual operation is typically full time tending, they are best suited to use with automatic controls, as Doble, White and many others did because of varying demand.

I have a foot in the steam car group as well. I see all three boiler types being used, they all work and they all have their advantages and disadvantages.

Personally, my favorite boiler type is the Ofeldt. It doesn't beat every boiler in every category, but all categories combined, I see it as the best boiler design there is.

-Ron

Re: Steam engine from the North Caucasus

Posted: Sat Sep 19, 2020 10:13 pm
by Freezerrr12
DetroiTug and RNoe thanks for all the information. I agree that an Ofeldt steam boiler would be the best option for my steam engine. I found a pipe 14 "in diameter and 4 feet long. Wall thickness is more than 15 mm. This pipe can be used for the Ofeldt steam boiler. However, I was able to find 28mm diameter steel tubes. (1 1/9 ") and 0.12" wall thickness. Such pipes cannot be used for an Ofeldt steam boiler, I have no way of coiling them, but I have no others. Applying 120 of these tubes to a Durham Donkey Boiler will give at least 100 sg / tf heating surface. However, such a water-footed boiler would have an enormous weight, over 1,000 pounds. I cannot make such a boiler, even with my assistants, who cannot work for me for free. My question is this: is it possible to manufacture a boiler with water pipes of such a significant thickness? Someone made such boilers, does anyone have experience of such work? I would be grateful for any information. In Russia, such small steam boilers for boats are not made, I know only one person who built a 13-foot steam boat that traveled about 30 kilometers. I am the second person in Russia who decided to manufacture a steam engine for a sailing boat. I have no experience in building a steam boiler. Your site is a small information miracle for me.

Re: Steam engine from the North Caucasus

Posted: Sat Sep 19, 2020 10:26 pm
by Freezerrr12
DetroiTug and RNoe thanks for all the information. I agree that an Ofeldt steam boiler would be the best option for my steam engine. I found a pipe 14 "in diameter and 4 feet long. Wall thickness is more than 15 mm. This pipe can be used for the Ofeldt steam boiler. However, I was able to find 28mm diameter steel tubes. (1 1/9 ") and 0.12" wall thickness. Such pipes cannot be used for an Ofeldt steam boiler, I have no way of coiling them, but I have no others. Applying 120 of these tubes to a Durham Donkey Boiler will give at least 100 sg / tf heating surface. However, such a water-footed boiler would have an enormous weight, over 1,000 pounds. I cannot make such a boiler, even with my assistants, who cannot work for me for free. My question is this: is it possible to manufacture a boiler with water pipes of such a significant thickness? Someone made such boilers, does anyone have experience of such work? I would be grateful for any information. In Russia, such small steam boilers for boats are not made, I know only one person who built a 13-foot steam boat that traveled about 30 kilometers. I am the second person in Russia who decided to manufacture a steam engine for a sailing boat. I have no experience in building a steam boiler. Your site is a small information miracle for me.

Re: Steam engine from the North Caucasus

Posted: Sat Sep 19, 2020 11:34 pm
by Freezerrr12
I salute the steam engine enthusiast. I thank for the answers. I came to the conclusion that it was impossible to build two steam boilers. I don't know how, but I will probably start building a water-tube steam boiler. It will be heavy too. But in a week I will buy 100-120 meters of 1-1 / 9 inch steel tubing. I will use these tubes. Thank you all for the appreciation of my efforts. I am not alone in the construction of a steam engine. I have an assistant for particularly precise work. I ask you to re-answer my question from the respected Kelly Anderson: how bad for the operation of a steam engine will a large section of steam ports in the HP cylinder, which is 1.4 square inches, instead of 0.89-0.87 square inches, be? Will this cause increased steam consumption? Will it cause a decrease in revs and a drop in power? Will the steam engine run unevenly? Is there a need to increase the HP cylinder diameter to 105-110 mm? I borrowed the design of the steam box (zolotnik) from a book by Richard Sennett. Steam is released from one steam port. I am attaching photos of making a steam box. I'll send the plan later.