Buffer tank for biomass boiler

[f0ster]

to regulate the heat output from the boiler is not always easy, depending on the boiler type you not only have to regulate the chip feed rate but also the primary and secondary fan speeds to match the feed rate. and also you really need the flame temp to be well up above 600 deg, 700deg is quite often the upper limit to make the boiler last longer. with heat exchangers you size them according to what you want it to do, for example to get instant hot water without the need for a hot water tank it required quite a large plate area because you are taking cold water to 60 deg within seconds, where for a house heating system it can be a lot smaller because it can circulate many times to build up the heat. you do not have to always use a PHE, it just makes it easier for working on the system and less damage done if you get a leak somewhere. there is only so much water you can pass through a given size of pipe without creating cavitation.

 

[Thick Farmer]

I am guessing house existing heating system !What you heating ?

Heating a grain drying floor and using a couple of massive radiators to exchange the heat.

 

[f0ster]

it might work ok, we had four 200kw froling boilers heating four large radiators/fans, one rad each. the mixer was starting to open the bypass because the return temp was hovering at about 50 deg

 

[Thick Farmer]

it might work ok, we had four 200kw froling boilers heating four large radiators/fans, one rad each. the mixer was starting to open the bypass because the return temp was hovering at about 50 deg

I'll give it a go then - worst case scenario is having to fit a buffer tank if it doesn't work.

 

[Doing it for the kids]

Heating a grain drying floor and using a couple of massive radiators to exchange the heat.

I hope they don't leak

 

[Bloders]

expansion vessel will need to be in the order of 4% of system volume - dont underestimate how big they need to be
second point, dont underestimate how expensive it can be to insulate a buffer tank.
as usual, we did ours on the cheap, but to do it the "regular" way would have cost about 2K in insulation, plus the labour of fitting it. Saying that though, its very good stuff - water can be at 80 degress inside and you cannot detect a temperature tise on the outside.

 

[Doing it for the kids]

Just spray foam, 60000 litres cost me about 3 k this spring

 

[Bloders]

Just spray foam, 60000 litres cost me about 3 k this spring

that could be a significant figure which could be overlooked.

what thickness is yours?

 

[Doing it for the kids]

100 mm.

When you work out the cost saving it's enormous

 

[strawman]

I want to put a buffer tank on my biomass boiler system.

Will a steel diesel tank be strong enough or will I need something more like a propane storage vessel?

Has anyone tried this before?

 

[strawman]

We have three 999kwh boilers each with a 100m3 buffer tank. These are available second-hand from glasshouse companies in Holland. Expensive option but well worth it as the boilers are kept working all the day and night. Biomass boilers are better run on a constant load

 

[Bernt]

No buffers on a log boiler!!!!!!! and no expansion vessel on a sealed system - i'd be reporting your installer and get it done properly, just a matter of time till you post that your pipework has burst and blown your house up!!!!!!! Also most reputable biomass boiler manufacturers state expansion should be 10% of system volume. 5% is currently recommended by CIBSE for domestic and small scale heating systems.