Londinium R arrived - Page 22

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FotonDrv

#211: Post by FotonDrv » Feb 21, 2017, 6:36 pm

Here is a question for you LR owners, or anybody else that would possibly know.

What is the purpose of Part Number 1?? And how does it work?

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That Light at the End of the Tunnel is actually a train

febi

#212: Post by febi » Feb 21, 2017, 6:55 pm

I do not own a Londinium R but it has to be the tube that acts as a heat exchanger. Cold water flows from the reservoir through the boiler into the group.

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FotonDrv

#213: Post by FotonDrv » Feb 21, 2017, 10:25 pm

There is a large tube that run transverse across the boiler and that "Dip tube" is inside it.

Here is the HX inside the L1 boiler.
Image
That Light at the End of the Tunnel is actually a train

okmed

#214: Post by okmed » Feb 21, 2017, 10:42 pm

I believe the dip tube delivers the cold water to the opposite end of the heat exchanger from where the hot water is drawn off.
Similar to the dip tube of a hot water tank sending cold water to the bottom of the tank while the hot water is drawn from the top.

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FotonDrv

#215: Post by FotonDrv » replying to okmed » Feb 21, 2017, 10:53 pm

That was sort of what I thought, but why do they call some machines "Dipper" machines and others HX machines? Is this a blend?
That Light at the End of the Tunnel is actually a train

okmed

#216: Post by okmed » Feb 21, 2017, 11:21 pm

I'm not familiar with the specific flow schematics of that machine but the way I understand it, a dipper supplies boiler water directly to the group and a heat exchanger is fed with cold supply water that is separate from the boiler which is heated in the heat exchanger and then goes to the group. Is that drawing a "R" ?

Edit: I see the drawing is labled an "R" so that's the heat exchanger I explained above. I don't see it as a blend but a straight heat exchanger.

I just took a look at the pictures of the internals and it looks like the ends of the heat exchanger are connected to the group via a thermosiphon which may be why you see it as a blend but I would still call that a straight heat exchanger. The dip tube would bring the cold water to the end where the cooler thermosiphon water returns. This is my interpretation, whether it is right or wrong, I don't know for sure.
Frans could probably shed more light on this.

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g3dahl

#217: Post by g3dahl » Feb 22, 2017, 2:20 am

Below is a diagram of a heat exchanger (HX) feeding a typical E61 group. The LR's HX runs horizontally through its boiler, but you can see where the water goes. Notice that the boiler water never reaches the group; it only shares its heat with the water inside the HX.

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The L1 (2013-16) and LR both have the same boiler and heat exchanger, but their operating principle is significantly different. In the L1, the supply to the HX's injector tube comes from the boiler itself by way of the "trombone tube." But the LR's injector is fed with cold water from the reservoir tank, under pressure by a rotary pump. Fresh water to the boiler is supplied by the same pump, but through a separate circuit.

During preinfusion, the legacy-design L1 can only deliver 1.3 bars of pressure because it is the pressure in the boiler itself that pushes the water through the HX and into the group when the lever is raised. Because the LR's HX is fed by the rotary pump, much greater (adjustable!) pressure is available.

If I understand correctly, neither machine is a "dipper," which would have its group connected directly to the boiler instead of having an HX at all. The legacy-design L1 has a hot-fed HX; the LR has a cold-fed HX, along with its big brothers in the product line (LI, LII and LIII).
LMWDP #569. Long live lever lovers!

okmed

#218: Post by okmed » Feb 22, 2017, 8:18 am

Thanks for the drawing and explanation Gary which clarifies what I was trying to say. I think it was the legacy L1 hot fed heat exchanger that Stephen is calling a blend.

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FotonDrv

#219: Post by FotonDrv » replying to okmed » Feb 22, 2017, 11:26 am

I asked if it was a "Blend" because the nomenclature states dip tube but was specifically asking for clarification and Gary has very eloquently shown what is going on.

If Londinium put out such nice diagrams it would be easier to understand for us uneducated folks :)
That Light at the End of the Tunnel is actually a train

Kfir

#220: Post by Kfir » Feb 25, 2017, 1:27 pm

I've managed to eliminate the spring "groan" on my machine, see here:

Eliminating Spring noise on a commercial lever (Londinium R)

Kfir.