elco burners and how to adjust

[adrian lav]

i have installed a firebird burner with the new ELCO burner the burner is factory set with a 0.65 nozzle i want to downsize the nozzle to a 0.60 as i feel the output is high, i am finding it difficult to get measurements ie pump pressure distance from diffuser etc would appreciate any help thanks

 

[SJB060685]

Have a read of this. Range rate it down to the next possibly, alternatively do your calculations and work out nozzle size and pump pressure. It’s cold out now so read the CO2 percentage to outside air temperature chart and adjust accordingly. Might take a bit of fiddling to get it running smooth.

 

[SimonG]

The burner will have 3 lots of settings to cope with it's full kw range. Each setting has it's own nozzle size, albeit not easy to find in the firebird/elco literature.

Interested to know why you find the rating too high though? Did you do heat loss calcs for new boiler? Is it a combi boiler, because if you downrate it you will effect the hot water performance.

 

[adrian lav]

The burner will have 3 lots of settings to cope with it's full kw range. Each setting has it's own nozzle size, albeit not easy to find in the firebird/elco literature.

Interested to know why you find the rating too high though? Did you do heat loss calcs for new boiler? Is it a combi boiler, because if you downrate it you will effect the hot water performance.

The burner will have 3 lots of settings to cope with it's full kw range. Each setting has it's own nozzle size, albeit not easy to find in the firebird/elco literature.

Interested to know why you find the rating too high though? Did you do heat loss calcs for new boiler? Is it a combi boiler, because if you downrate it you will effect the hot water performance.

No it isn't a combi boiler the output i was looking for was around 70000btu which I could achieve with a smaller nozzle ie o.6 or less . I was always operating on the basis that condensing boiler vwill perform more efficient when slightly undersized ,its just that the manuals are very poor with the necessary specifications when you purchased the standard burners you were always provided with the necessary data to adjust the burner within a specific range ie 70000 to 90000 btu doesn't appear the case with the new elco burners

 

[SJB060685]

The burner will have 3 lots of settings to cope with it's full kw range. Each setting has it's own nozzle size, albeit not easy to find in the firebird/elco literature.

Interested to know why you find the rating too high though? Did you do heat loss calcs for new boiler? Is it a combi boiler, because if you downrate it you will effect the hot water performance.

If proper heat loss calculations were done then the design outside temperature will be known. If 23KW were needed at say 5°c then a bit more for say -5°c, in which case down rating it isn't neccessary.
If the OP has installed a combi then yes down rating will have an undesired affect on HW performance, although he didn't mention it was a combi.
Although the manual only states 3-4 output ranges, anyone who understands the pressure jet burner and its components should be able to set it up to run pretty smoothly. Perhaps the main concern here is the position of diffuser plate and combustion head but again if someone knows which each part is doing then technically you could create a custom setting, this of course might take some fiddling as I mentioned above.
There is a response from the OP which we can't see yet. Hopefully that will reveal more.
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No it isn't a combi boiler the output i was looking for was around 70000btu which I could achieve with a smaller nozzle ie o.6 or less . I was always operating on the basis that condensing boiler vwill perform more efficient when slightly undersized ,its just that the manuals are very poor with the necessary specifications when you purchased the standard burners you were always provided with the necessary data to adjust the burner within a specific range ie 70000 to 90000 btu doesn't appear the case with the new elco burners

You have to remember that heat load varies with outside temperature. At -5 will require more output than at +15 on a summers day, which is why I mentioned above. If you've done some basic calculations for boiler size I would leave as is and take it from there. You also have to remember that radiators are commonly upsized or downsized to the closest, so there are variables there too.

 

[MickH75]

Have a read of this. Range rate it down to the next possibly, alternatively do your calculations and work out nozzle size and pump pressure. It’s cold out now so read the CO2 percentage to outside air temperature chart and adjust accordingly. Might take a bit of fiddling to get it running smooth.

A lot of mumbo jumbo is bantered about when setting burners and always has been in over 50 years of my experience. Basically a nozzle will produce atomised fuel and if it is kero it atomises at quite low pressures which is handy because if you lower the pump pressure slightly which of course relates to heat input and then adjust the air in so that the combustion efficiency is correct ( just enough air to obtain a clean flame to whatever the pump pressure is) there might well be no need to change the nozzle. each nozzle is not fixed to a fixed output but relates to a maximum output. Or have I got it wrong for 50 years?
Incidentally I had a customer that would not buy kero, only diesel in bulk (probably ran a tractor on it). it was only a 25kw fabricated boiler. I rang Selectos and the very amiable tech said when I asked him if anything was new on the diesel front (donkeys years ago)...... He said yes latest info = bang the pump pressure up to 200 psi = never a problem with ignition on cold start ups! I always am thinking is that the answer for burning neat Bio diesel?
Well these newfangled common rail engines run very well on it but consider the pump pressure in such devices =24,000 psi ! pump pressure with diffuser and draught tube carefully designed and hey presto a clean bio diesel flame. Does the Elco burner run on neat bio diesel = B100.
Some of the cleaver USA bio diesel experimenter say they run Beckett burners on neat Bio without too much diffuser contamination but that is what they 'say'. Is it true?

 

[SJB060685]

You need a minimum pressure for any type of fuel oil to atomise and be ignited, yes on cold days you could get ignition problems if the pump pressure was to low. Diesel oil is more viscous and therefore typically set the pump to a slightly higher pressure, they also commonly have a pre heat function to help ignition stabalise and then switches off. I think if I remember correctly the rating on a nozzle in gph is for a pump pressure of 100psi. As you say adjusting up or down will adjust the volume and output.
The EOGB boiler I mentioned above is quite sophisticated. On the pump is a pressure transducer, this is constantly monitoring the pressure and based on your opentherm signals will help modulate to a correct output. Obviously the air intake is modulated as well.