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Hi Edmond.The pumps are very typical of the ball type that are common in model steam engine and boiler feed pumps in that they have a ball on the suction side and one on the delivery side with the pump having a ram type plunger.I don't have any drawings of these pumps other than the sketches in my note books and regarding the types of materials used in the engine I can only offer to mail you a copy of the original builders article which was published in Model Engineer Mag which can answer your questions on materials used, please contact by P.M. don't put your e-mail address on the forum.I must question your ambition to control this plant as it is designed as a racing plant which in the original Hydro achieved 120 mph and possibly higher now. This plant is uncontrollable and is a bit of a beast when let go, as it is a closed loop pressurised system any opening of bleed valves immediately loses pressure and the engine stops.The pumps have a fixed stroke and driven from a disc on the 90 deg cross shaft and is adjustable via holes on the disc and by experimentation the correct stroke is found.The fuel system is preheated in a vaporizer of 3ft long x 3/16" dia Stainless 316 tube stuffed down the coil and is heated by a plumbers blow lamp to get the burners going before starting, just like a Primus stove. Regarding fuel efficiency on this plant it's not a consideration as it tries to burn as much fuel as possible to give the highest temperature and pressure available, I hastily add that I have no idea of the pressures or temperatures when the plant is on full song.The lubricator is worked from the cold water pressure and bleeds high grade steam oil into the engine every time the valve lifts on the engines rev cycle.All that it is is a cylinder with a free fall piston inside , it's pushed down and filled with oil when the engine isn't running and once running the pressure builds and injects the oil thro' a .025" hole into the steam line every time the valve lifts..Now back to controlling the engine, this plant is designed purely for high speed racing, record breaking, with no thought of controlling the speed, as far as I know nobody has ever tried to speed control it but you are welcome to have a go.I can recommend the book EXPERIMENTAL FLASH STEAM by J.Benson and A Rayman which catalogues various steam plants from the past with dimensions of pumps and many other suggestions.I do hope that this information helps.George.
This developer has spent a lot of time trying to do what you propose.http://www.flashsteam.com/Lohring Miller
Has anyone looked at the numbers for fuel and water output from the pump. I may be wrong, but I get around 16 cubic inches per minute of fuel and 30 cubic inches per minute of water at 1600 pump rpm. For the fuel that gives around 175 horse power of heat at 17,900 BTU per pound of fuel. That's reasonable since the power plant can't be more than 5 to 10% efficient at converting the fuel to shaft power. At 5% that would be 8 3/4 hp.However, I get 1 pound per minute or 60 pounds per hour for the water. Even really efficient engines use 10 pounds of water per hour per horsepower. It's more common to use 20 to 30 pounds per horsepower per hour. Did I screw up my calculations or is there a reason for this discrepancy? From my experience with a 110 mph RC hydro that ran a dyno tested IC engine, I would expect that it takes around 5 or 6 hp to go 120 mph. Lohring Miller
Quote from: lohring on January 06, 2014, 06:46:07 PMHas anyone looked at the numbers for fuel and water output from the pump. I may be wrong, but I get around 16 cubic inches per minute of fuel and 30 cubic inches per minute of water at 1600 pump rpm. For the fuel that gives around 175 horse power of heat at 17,900 BTU per pound of fuel. That's reasonable since the power plant can't be more than 5 to 10% efficient at converting the fuel to shaft power. At 5% that would be 8 3/4 hp.However, I get 1 pound per minute or 60 pounds per hour for the water. Even really efficient engines use 10 pounds of water per hour per horsepower. It's more common to use 20 to 30 pounds per horsepower per hour. Did I screw up my calculations or is there a reason for this discrepancy? From my experience with a 110 mph RC hydro that ran a dyno tested IC engine, I would expect that it takes around 5 or 6 hp to go 120 mph. Lohring MillerHi Lohring,Like the Hydro record chasers I have never been concerned with fuel consumption other than trying to burn as much fuel as I can and getting as much heat from the fuel as possible.I don't disagree with your figures although they don't correspond exactly as per K.N. Harris's in his book on Stationary and marine Steam engines but near enough, these figures are for Saturated steam not high pressure flash steam.I have done a little Calc using H.P. figures as P.L.A.N divided by 33000 which is how I have always calculated H.P. but as I don't know what pressure my Steam plant works at I have used theoretical figure on Steam pressure based on what the record chasers can achieve which can be as high as 3000P.S.I.I have used 1000 P.S.I. and from the Calcs it comes out at 14.06 H.P.500P.S.I. would be 7 H.P. and 2000P.S.I would be 28.12 H.P.My pumps work at 6/1 from the main shaft so at 15000 rpm it will be 2,500 strokes per min.The water pump at 1/4" dia x 3/8" stroke delivers 45 cub " /min The fuel pump at 3/16" dia x 3/8" stroke delivers 25.46 cub"/ min.These figures are theoretical as in the water the revs will be lower, I think the only way to get accurate figures on pressure and steam temperature is to have gauges to monitor them on bench testing.I can tell you that I ruined a 300 P.S.I. gauge on the steam line in one of my efforts to find out the pressure, due to the modulating pressure as the valve opened and shut it blew the gauge apart , so I very quickly abandoned the idea of measuring the pressure but I am sure that there must be more reliable methods of measuring.So, some food for thought.George.HAPPY NEW YEAR TO ALL, BEST WISHES FOR 2014
GeorgePlease forgive me. I meant no disrespect of denouncement in the least!....I love reading and learning this build. It's fascinating!.... Please accept my apology if I came across in a negative manner, as it wasn't my intent at all. 3000 PSI!......Yikes!...Dave