Chris's Holly Pumping Engine Build

[RReid]

Great to see all those parts start coming together. I'm sure you could see it in your minds eye, but I sure couldn't. Looking fantastic, per usual! 

[crueby]

Great to see all those parts start coming together. I'm sure you could see it in your minds eye, but I sure couldn't. Looking fantastic, per usual! 

Thanks Ronald! Even with the CAD model of it, and seeing it the minds eye, I STILL keep putting some of the parts on backwards the first time!   

[EricB]

Hi Chris,

Looking at your pictures I'm wondering if your pipe arrangement will fit in your housings.

Eric

[crueby]

Hi Chris,

Looking at your pictures I'm wondering if your pipe arrangement will fit in your housings.

Eric

Well, elf-exhaust!  Where were you yesterday?   

Yup - you are right, those caps are fine for the lower housings where the pipe extends out and is capped, but not on the upper housings with the blended in pipe ends. Huh. Never spotted that one - did all the modelling in CAD for the pipework on the middle housing. Whoops.   

Not a big problem, I can trim off the end of the Tee and put in a plug instead. The tee sections work, but would have been better done with an elbow in that one place. Those upper assemblies are the first to go in the housings, so I would not have gotten very far!  Thanks much for the catch!!!   

The (butt)-crack rework team is on it:

[cnr6400]

 

[Kim]

That looks really slick, Chris!   

Boy, some people are following very closely to be able to catch that!  I'm still trying to catch up to what it's going to look like when assembled!

Great work.  I'm sure you'll get this little hiccup worked out quickly!

Kim

[crueby]

Thanks Kim!  As for what it is going to (hopefully) look like, the pump section of the engine is circled in this picture. Probably another couple months to get that level done, then on to the actual engine above it! There is a maintenance platform about the level of those smaller hatches above the ladders still to make, that does not show well in this picture. Plus a bunch of smaller pipes/valves. The pump plungers too, they connect in to the crossheads above, with the clusters of vertical rods visible around the con-rods. I've got castings for the flywheels, those are going to be fun to machine down, they are 8" diameter, 1" thick, quite heavy.

[crueby]

Got lucky - trimming those end caps off at an angle did the trick! They now fit inside the upper housings with the blended end pipes.   

[Kim]

Thanks for posting that - I know you've shown the whole thing before, but seeing here, after watching that whole pump section come together - REALLY gives me a feel for the size of that monster.  The lower pump section must be 20' tall or more (judging from the guy standing there). 

You could mill the fly wheels using your RT? 

And a slightly different question - those big pipes coming up at an angle on the right side - are those for the steam? Or something else?

Kim

[crueby]

Hi Kim,


These engines really are ginormous. And there are five of them in that building! Truly awesome sight.


The flywheels will be done on the lathe, have done others this big before. The Sherline headstock can be turned 90 degrees so the flywheel is hanging off the back, allowing the rim and one side to be turned at a time. I could also put in two riser blocks and turn it over the bed, but that gets iffy for rigidity and tool angles. I want to put in a taper lock which would be a tricky setup, or may stick with a keyway. Have not decided yet, that is months away still.




Those angled pipes on the right are the exhaust from the LP cylinder coming down to the condensor, which is a set of heat exchanger pipes inside a drum cooled by the pumped water. Another small pump sends that water out, not sure if the sent it back to the boilers. The condensor was added later, so is not in the plans. The input steam line is a smaller vertical pipe in the left end in that picture.


 

[gary.a.ayres]

Looking great!

[crueby]

No progress posts from the last couple days, but progress is being made. With the nice weather finally here, lots of outside time, but I have started assembly of the pumps. A couple of the parts needed some fettling for a proper fit, and I did some extra sealing on the tee/pipe joints since I don't want to have to take it all apart again later for any small leaks. Pictures are coming, going to wait till its all together so I can show the sequence all at once so it will make more sense.
For now, back outside, nice warm sunny day!
 

[gary.a.ayres]

 

[derekwarner]

Chris.....just thinking about basic pump engineering where 2 or more pistons displace fluid into a common discharge 

Now I understand each cylinder has it's own check valve bank, however to maintain efficiency, check valves are located on intermediate discharge ports to stop the pressurized fluid from being forced backwards....I believe these may have been necessary due principally due to the huge volumes of fluid involved within the common discharge

This 3rd check valves could have been located in a common T spool, being for 'easy' service - the Pump Machine Engineer would have seen a brace of pressure gauges with constantly ranging pressure, as the pressure is achieved in 1 cylinder, then decay ...an repeated by 15 x 6 = 90 individual gauge pressure fluctuations per minute, if the machine was 15 RPM

I am sure you understand my thought the check valves are in the two intermediate pipe spools

Derek

Oops, my error.. ....there should also be a check valve [shown] on the discharge spool of the 3rd piston as it is needed to stop pressured fluid going backwards to the opposite body of 3 pistons in the other 1/2 of the pump components

[crueby]

Hi Derek,
There is absolutely not another check valve in the pipes like you show. If they did, that pipe would have to have been a lot larger diameter to put in another huge array of small check valves - they did not have the technology to make a single large check valve, maybe they do today in pipelines, I don't know.


Here is a cutaway view of what they did do, this is taken directly from the original builder blueprints, just converted to a 3D model:



A description of the operation for any interested. The orange arrow in lower right shows one pump cylinder with the side wall cut away to show the plunger inside. The purple arrow shows one of the two valve housings for that cylinder cut away, with the inlet pipe coming in from the left. The water, under slight pressure since this chamber is a little lower than the level of the lake outside the building, would be drawn in through the lower check valves, red arrow, as the plunger goes up. When the plunger reached the top and stopped, those lower check valves would close, they are spring loaded valves that look a lot like an IC engine valve.  When the plunger pushed down again forcing the water out of the pump chamber, the water would flow through the upper bank of check valves shown by the green arrow, and out through the output pipe (blue arrow). The connection of the output pipe to the chamber above the green arrow was cut away so the valves would show. In that upper chamber, shown where the orange circle is, they piped in compressed air to act as a buffer for the changing pressures and prevent water hammering. The air partially filled the top of that chamber. House type pumps on wells have the same feature. There is another air chamber like that on the output pipes where they meet in the big Y pipe to the right, not shown in this picture.
They did not use check valves in the common pipes between these housings. Maybe they would on more modern systems? The three pump plungers are worked by the engine pistons above, so they are 120 degrees out of phase with each other. That means that the flow in the pipes IS fluctuating some, would be the combination of the three sine waves created by the three pumps, with less total variation than there would be from one pump acting alone. The air-filled force chamber reduced the bouncing of the water flow but it would still be there.

Derek, back to your original question, while a more modern system may be designed differently given the way they can computer-model the flows to make it more efficient, for early 1900s this is what they had. It had to work well enough since it ran till about 1980.  Its fascinating to compare it in size to the electrically driven turbine pumps they replaced these engines with.

These pumps sit right next to the old steam pumps, in one of the bays they had left to add more steam pumps for future expansion needs. About the same footprint on the floor as one engine/pump, a tiny fraction of the height, and they feed a city that has grown a lot.
Now, let me say that I am NOT a fluidics expert in any way, except how to drain a beer glass. The design of a more modern plunger pump system is way beyond me - might be a good discussion topic over in MJM's thermodynamics discussion thread!