Wood heating and pollution

[Did67]

Then, if you already have a condensing boiler, most of the work is almost done already. But I find it even more pity not to use the remaining ° c to heat a double flow, since the risks of soot have almost disappeared.

...

There, I think you are wrong. Because at the outlet of the condenser, the air is saturated at the temperature at which it leaves. Between 30 and 40 ° at home. By definition of condensation.

So if you refrefoit it again (let's say you pass it from 30 to 20 ° C), you will condense the difference between the water contained in the air at saturation at 30 ° and that contained in this same air at 20 ° C.

Furthermore, it is true that the condenser reduces the share of PM (particles) emitted by the boiler. Condensing boilers are the cleanest that exist (that's why I chose this option; because at 2 € per bin, at the current price of pellets, its financial profitability is not obvious). But there are still some! They emit much more than fuel oil and especially gas heaters ... (it is not for nothing that condensation first developed on gas).

I continue to doubt that a VMC DF swallows this! Durably, means ...

But give it a try, guys. My "attention" is not to say "do not do", it is to say "attention, do good! It will not be easy" ... That we do not understand each other.

For my part: 1) not enough "DIY"; 2) many other projects in progress; 3) lots of other opportunities to save (I am on our fleet of cars - a challenge far more massive than the 5 or 6% of heat "lost" in the gases of my boiler ...). It's totally personal, that ...

[bernardd]

To protect the tank to collect the condensate, fingers and plants :-) And to avoid turning on acid vapors too, but not really sure that it is necessary.

It still allows to note that nature keeps a certain balance: acid in the fumes, basic in the ashes :-)

[bernardd]

Thank you Did67, well understood your help, no worries: it's good to think, in order to do your best from the first try.

The shadok logic makes me laugh ... but seen in others ;-) (I have a 1 in 1 million chance, so I hurry to miss the first 999 tries ...)

[chatelot16]

I will rather conclude that it is the fire that makes the mess: before burning it is neutral, after acid in the smoke and basic in the ash

[Did67]

To protect the tank to collect condensate, fingers and plants

It's not the bottom that worries me, you hang u Tupperware in plastic and voila.

It is the heart of the system, where it condenses, that is to say the "plates" ... No matter how you set up your system, you will have large surfaces (otherwise, you will not collect large thing, like calories, with on one side water from a heating circuit and on the other, smoke + acid condensate ...

It will be the coldest point, so there that it will condense ... And there also that it will corrode ... And there again where the particles will agglomerate with the condensate ...

It would surprise me that you "neutralize" fumes ... Acidity is by definition for a solution. The salts are "neutral", you put them in water and you have an acidic (or basic) solution ... Archi-dry salt does not corrode anything. It is when there is water that it spoils ...

Then there are also the recations between metals and gas ... Another problem in your condenser. Ex: copper + SO² (from memory; if it is not it, it is another polluting gas) gives "verdigris", This portège salt but it is also slightly soluble ... So copper is " corrodes "very slowly, but corrodes ...

Given the composition of the fumes, phenomena like this, you will have a lot. In my opinion...

We say "ashes are basic" ... It's an approximation. Ashes are basic when you dissolve them, or put them in the ground where they will be dissolved ...

The gasifier, yes, when you make your gases "bubbled" to collect the gases or salts in solution ...

[bernardd]

The gasifier, yes, when you make your gases "bubbled" to collect the gases or salts in solution ...

Splash around? If we do it for gas, can't we do it for "smoke"? it would still be the best heat exchanger, without corrosion ...

What about aluminum? it would be more protected than copper, again. And it is still good for thermal conductivity.

[chatelot16]

I considered as a recuperator recuperator with condensation a sprinkling of water: the exchange surface between the smoke and the water is enormous, the heat of the water is easy to recover, we can add to the water what not to be corosive: the problem is the CO2 which eats too much basic product: the ash is not enough

it looks like it in the exhaust of many boat engines: we mix sea water with exhaust gases from the engine outlet: it cools the exhaust pipe and dilutes the acid of the bad fuel rich in sulfur

for gasifier gas the shower of water and lime works well

[bernardd]

Yes, we should also be able to bubble :-) But I have no idea of ​​the pressure drop.

Or the flow for that matter. I found "Flue gas flow rate at Nominal Power kg / s 0,034 - 0,047" on the instructions for a boiler that you would like (gasification :-) (vigas, I did not know) between 18 and 29KW.

If we take 1kg of gas at 1m3 to simplify, it should be between 122 and 167m3 / h: it is the order of magnitude of a VMC, right?

between 7 and 6 m3 / h.KW

By the way, I wonder what would happen if we injected oxygen enriched air? for example from 20% to 30%?

[chatelot16]

of course if you enriched with oxygen you decrease the flow rate by avoiding passing unnecessary nitrogen there, it is done for industrial furnaces at high temperature, or despite the price of oxygen the increase in efficiency is good a benefit: oxycombustion: pure oxygen

for a heating boiler it is without interest

[bernardd]

If there is pressurized air (future tanks at 300 bars for cars ... damn, censored for some ;-), we can select oxygen, through specific membranes. But one more complexity, that's for sure, and even by increasing the oxygen from 20% to 40%, we would only divide the air flow by 2. Not sure that it is useful, except that it would decrease can -be the NOx rate.