How long have we urban dwellers got?

[openspaceman]

5 hours ago, Canal Navvy said:

I'm expecting to see that a leading technology company is close to production of a domestic particle filter and is busy creating a market.

It'll start with a big tax payer funded grant for the posh houses to build the market and will finish with a mandated service contract for the masses 🤫

Funny you should say that as I have turned my thoughts to a simple electrostatic filter that you switch on when you light the fire and it switches off when the flue temperature drops to show the fire is out. Servicing it at the chimney pot is the biggest problem plus the only firm that sells them wanted £1800 some years ago.

 

The thing is the percentage of particulates in the air due to wood fires was bound to go up as other sources of combustion derived particulates were reduced. Think back to 1990 (if you are old enough) when straw burning filled the air with smoke in late summer, now not done, garden green  waste collections have cut bonfires and then we have diesel particulate filters, adblue and catalytic converters reducing pollution from transport plus EVs becoming popular.

 

I am adding insulation to my house, mostly because I may not be able to collect logs and when I am gone my partner definitely won't. I have left it too late really as it has been amazing how much my gas and electricity consumption has dropped.

[neiln]

Oh and like you I'm paranoid.  I don't get on with a near neighbour and wouldn't put it past him to dob me in if he could.  I make sure I burn clean so he has no reason to.

[openspaceman]

4 minutes ago, neiln said:

I don't qualify?!  I'm in London, inside zone 3 on the tube map (just)

 

I'm sorry Neil I was confusing you with @nepia.

 

Yes the only reason the post war labour government went down the magnox route was to produce plutonium (because the air cooled core at windscale overheated due to the graphite core suddenly releasing its stress and burning the uranium being bombarded with neutrons. It is doubtful that any of these and the later Dounreay fast breeder ever covered their build and operating costs let alone their decommissioning.

[neiln]

Oh and I've not received any comments about how bad I am for burning, most of my street see my front garden that looks like a landing from 'big timber' all summer and one (yes him) regularly complains about my chainsaw noise, but most are confused and clueless about what I'm doing as I burn so clean.  I regularly get asked what the wood is for! 🤣

[Muddy42]

3 minutes ago, openspaceman said:

I don't believe so, the faster you dry the log the less dry matter is respired by bugs and the more energy is available for combustion. Wood essentially burns to carbon dioxide and water as long as the three Ts are catered for

 

Time for the combustion to complete (in the order of a second for a flame)

Turbulence to allow for better mixing to increase the chance of a fuel molecule meeting an oxygen molecule (within the time above).

Temperature in the combustion temperature which every molecule is subject to (in the time above) and its 850C.

 

Plus supplying enough air to do the job (about 200% of stoichiometric for a simple stove).

 

I've always been told that if the wood is still rock hard and bound together by sap or covered in bark, the inner parts can't dry out, the water simply can't get out.  You need to wash out the sap and effectively turn the wood into a bundle of straws. I understand though that a semi rotten wood theoretically has less energy BTUs, but maybe that the price you pay for a clean burn?

 

I guess you could test this - measure the moisture on the outside and then split the log and measure the inside. Really wet logs hiss when you burn them.  Isn't it the fact that the wood is wet that makes it burn cooler and dirtier.

 

Maybe a kiln can dry the inside of green logs? i have no experience with kiln dried logs.

[openspaceman]

1 minute ago, Muddy42 said:

 

I've always been told that if the wood is still rock hard and bound together by sap or covered in bark, the inner parts can't dry out, the water simply can't get out.  You need to wash out the sap and effectively turn the wood into a bundle of straws. I understand though that a semi rotten wood theoretically has less energy BTUs, but maybe that the price you pay for a clean burn?

 

I guess you could test this - measure the moisture on the outside and then split the log and measure the inside. Really wet logs hiss when you burn them.  Isn't it the fact that the wood is wet that makes it burn cooler and dirtier.

 

Maybe a kiln can dry the inside of green logs? i have no experience with kiln dried logs.

 

Wood will always dry down to it's equilibrium water content (below 17% wwb in England) given time and once this dry as long as it is not re wetted it will not degrade further by microbes eating it.

 

Yes bark is largely waterproof and yest a big round log will not dry in a summer, which is why crosscut and split so you can pick them up on and end one handed they will dry in a summer if there is enough air flow.

 

I have filled the log store I used between October and December 22 and half filled the January february one and they will dry out easily. The ash I am burning (or was as I let the stove out as it is warm) is showing at 12% on my meter and burns with a very lively flame.

[neiln]

You don't want rot, that's calories gone and more water to dry. You can dry too fast though and trap water.  If you kiln green wood you can close off the cell tube (not the correct name!) Ends and seal the tubes trapping the water.  It's fairly well known for timber producers I believe, they will allow a period of slower drying first, then kiln, to prevent it.  However I digress. Sorry!

[Paul in the woods]

31 minutes ago, openspaceman said:

Nooo. Now we have gone down the renewables route the cost and time delay of new nuclear is not worthwhile even before you consider the moral dilemma of leaving the radioactive waste for later generations to sort out.

I agree now, I meant when the questions were first raised so around the 1980s ? Or investing in our own gas supplies rather than relying on imports whilst renewables become more reliable.

 

The current prices are hardly a surprise and we've been very lucky to have such a mild winter far.

[openspaceman]

8 minutes ago, Muddy42 said:

 

Maybe a kiln can dry the inside of green logs? i have no experience with kiln dried logs.

I do have as it was my conceptual design, perfected by a colleague that supplied the first kiln to the county's biggest log supplier.

[GarethM]

No, log drying is a single stage.

 

Split and dry, some will ooze out the sap behind the bark, unless you kiln dry which crystallised the sap using heat.

 

A modern stove or boiler uses refractory concrete to burn everything at 2000c.

 

If it survives that it's probably not flammable.