Horizontal calorifier

[gary955]

How are the coils orientated in a horizontal calorifier? it occurs to me that if the coil is in line with the barrel (like a domestic hot water tank on its side) then the coil would be impossible to bleed without a powerful pump!

My horizontal tank has coil inlets and outlets opposite each other at the top and bottom of the tank. Do the coils run vertically across the tank so that air will naturally rise to be bled off at the top?

[BargeeSpud]

How are the coils orientated in a horizontal calorifier? it occurs to me that if the coil is in line with the barrel (like a domestic hot water tank on its side) then the coil would be impossible to bleed without a powerful pump!

My horizontal tank has coil inlets and outlets opposite each other at the top and bottom of the tank. Do the coils run vertically across the tank so that air will naturally rise to be bled off at the top?

Here you go:

 

 

 

Its from Tony Brooks' TB Training web site, so you can take it on very good trust.

Edited August 9, 2012 by Spuds

[gary955]

Here you go:

 

 

 

Its from Tony Brooks' TB Training web site, so you can take it on very good trust.

Thanks for that spud, but I think they are simplified diagrams to demonstrate concept rather than to illustrate actual layout. The horizontal one doesn't look very convincing.

[BargeeSpud]

Thanks for that spud, but I think they are simplified diagrams to demonstrate concept rather than to illustrate actual layout. The horizontal one doesn't look very convincing.

OK, see if this one clarifies things a little better, its a drawing of a marine calorifier.

 

 

I should imagine that manufacturer's designs will differ from each other, so maybe try the manufacturer who's calorifier you're interested in, directly.

[RLWP]

How are the coils orientated in a horizontal calorifier? it occurs to me that if the coil is in line with the barrel (like a domestic hot water tank on its side) then the coil would be impossible to bleed without a powerful pump!

My horizontal tank has coil inlets and outlets opposite each other at the top and bottom of the tank. Do the coils run vertically across the tank so that air will naturally rise to be bled off at the top?

 

I doubt you will have any problems with air in the coils. The engine pump will purge one coil, the central heating pump will purge the other. It is more usual to get problems with air trapped in the hot water tank

 

Richard

[gary955]

OK, see if this one clarifies things a little better, its a drawing of a marine calorifier.

 

 

I should imagine that manufacturer's designs will differ from each other, so maybe try the manufacturer who's calorifier you're interested in, directly.

Ahh that looks better As I had hoped, coils across the barrel so able to purge air. Hope all horizontal cylinders are like that, I'm unable to check with the manufacturer as there are no markings on it. I think I may have traced my problem with bleeding to a blocked header tank outlet though.

I doubt you will have any problems with air in the coils. The engine pump will purge one coil, the central heating pump will purge the other. It is more usual to get problems with air trapped in the hot water tank

 

Richard

No central heating pump I'm afraid......Thermosyphon. Hence the need to ensure it's fully bled. I drained it to install a block valve to stop the thermosyphon wasting all the hot water by heating the radiators from the (engine heated) hot water in the summer.

[RLWP]

<snip>

 

No central heating pump I'm afraid......Thermosyphon. Hence the need to ensure it's fully bled. I drained it to install a block valve to stop the thermosyphon wasting all the hot water by heating the radiators from the (engine heated) hot water in the summer.

 

Then taking one end off and letting the pressure from the header tank do the job should also work - as long as you have cleared the blockage

 

Richard

[nicknorman]

Not that I have any personal experience, but isn't it considered very difficult or impossible to persuade thermosyphon at a reasonable rate through small diameter calorifier coil pipes?

[bizzard]

I find i'm fairly regularly renewing the mains electric immersion heater elements in horizontal calorifiers and never in the vertical type. Something to do with the element trying to droop when hot, with gravity i expect.

[nicknorman]

I find i'm fairly regularly renewing the mains electric immersion heater elements in horizontal calorifiers and never in the vertical type. Something to do with the element trying to droop when hot, with gravity i expect.

No, the drooping will be caused by the extra weight of the electricity when they are turned on. Of course not all things droop when they are turned on...

[dor]

My horizontal cal has all the connections at one end. The two coils are one above the other, so the bottom pair of connections go to one coil, the upper pair to the second coil.

 

The instructions say to connect the upper pair to the engine, the lower to the boiler, but I think that is aimed at yotties. I've connected the lower pair to the engine as I use that for hot water more than the boiler.

 

ETA: The engine coil purged easily enough, the boiler one took a little longer - turn the pump off to let it rest then on again every few minutes, making sure all the rad circuits are closed.

Edited August 10, 2012 by dor

[gary955]

I find i'm fairly regularly renewing the mains electric immersion heater elements in horizontal calorifiers and never in the vertical type. Something to do with the element trying to droop when hot, with gravity i expect.

Thanks Bizzard. You've provided the answer without even knowing it! I could drain the tank, remove the immersion heater and peer in the hole with a little torch to see the orientation of the coils myself.

I've cleared the blockage in the header tank but it's so full of scum & flaky rust that it keeps wanting to block again. I cant remove it from the engine room wall to give it a good old wash out, so i'll machine the BSP outlet boss to accept a little stub of 15mm pipe to upstand the outlet off the floor of the tank by about an inch. That ought to fix it