openspaceman

In fact the recent studies in Malawi where a large group were given clean battery powered stoves to use did not find a significant difference in health of under 5 year olds in the years of the trial. The population was so poverty stricken and malaria was rife plus particulates from rubbish burning and smoke from nearby housing overwhelmed any benefits the stoves could offer. This doesn't mean that striving to make better stoves is invalid but rather that the whole environment needs consideration. It also doesn't make the current fashionable ranting about diesel and woodsmoke directly attributable to killing people right.

Are you referring to something I posted?

Anaerobic digestion plant I guess, mix a load of food waste , silage and cow slurry up, heat it to blood temperature and the microbes give off methane and carbon dioxide from respiring the volatile solids in it. Methane and CO2 fuel a genset which supplies electricity to the grid and use some of the heat from the engine to keep the digester warm, the rest is available for other uses.

Yes I heard that and although they were talking in Fahrenheit I'd have to sit down and work the partial pressures of all the flue gas constituents to actually see if one could get that low (140F was mentioned which is only 60C) without water running back into your stove. In practice the 350F =~170 C which they mention as being a test standard for stoves is far more realistic for a flue exit temperature into a 2 storey chimney in order to avoid condensation in the chimney. If I change from the 100C figure I used to 170C the stove efficiency drops to 85%. It gets worse if you allow that the air actually comes from outside, as do the logs which may be at 0C.

You only need a complete ultimate flue gas analysis if some of the chemical energy is being dumped unburned up the flue, this is typically the case when smouldering damp wood. In a clean burn we can assume complete oxidation so all the chemical energy is release in the stove. Then the only heat loss from the system is what goos up the flue. This has two parts, the physical heat which is the specific heat of the mixture of gases times the difference between flue temperature and room temperature plus the latent heat of vaporisation of all the steam that goes as part of the flue gases.

What makes you think it was tosh? If you start with a closed warm room with a stove in it and a flue plus a means to replace air that is used in the stove then law of conservation of energy applies. Say you burn 1.25kg of wood at 20% moisture content and have to use 100% excess air to do so cleanly. If we define cleanly as no visible smoke and 30ppm CO then we can assume chemical energy losses to be around zero. Also ignoring ash content of the original mass. Then the energy content of the wood higher heating value is about 21MJ/kg. To burn this wood the rounded equation is something like this: (C5H7O3+1.45H2O)+11O2+44N2 =>5CO2+4.95H20+5.5O2+44N2 where the bit between brackets is the surrogate formula for wood at 20%mc wwb The N2 is inevitable as it is about 79% of air so you have to have it to get the oxygen you need. To burn the 1kg mass of wood with 20% moisture to extract 21MJ of heat you need to exhaust 8.8kg of flue gas and that includes 0.775kg of steam which you don't want to condense in your flue.To guarantee it won't condense it can be slightly lest than 100C but that's another story, we'll say it leaves the stove flue at 100C. We have heated up all this mass from room temperature to exhaust it at 100C that means we have raised the exhaust gases from about 20C to 100C, lets assume the same specific heat as of air about 0.001MJ/kg. Therefore our losses up the flue are the difference in heat in the flue from the original air and wood input plus the losses in converting the hydrogen in the input to steam, this equals ~2.5MJ out of our original 21MJ HHV and so the maximum stove heat efficiency into the room is 88% Where a mass heater scores is it releases the heat from the wood as above in a short hot burn but then no further mass flow occurs up the flue so there are next to no losses from a stove "ticking over" all the rest of the day.

Unfortunately I have been cancelled for this job as the boss's truck exhaust fell off and it will now be done without my assistance next week, I had the plastic woven sheet and rope in the car ready to try but will have to find another way to demonstrate the principle. That's Three jobs this week I've had cancelled 1) because the Dipso lady with the overgrown garden I recovered last season can't cope with visitors so the bramble growth will take over all the lawn. 2) the canter I arranged to borrow to move some logs didn't come back from repairers in time and now is back on roofing work 3) Boss's truck exhaust problem It makes retirement even more relaxing than I intended

Which is much as I was expecting would start happening

Yes Well components of it have definitely got the potential to cause or aggravate a condition which will shorten a life Yes and so have cancers associated with it, Polycyclic Aromatic Hydrocarbons arising from poor combustion of coal or biomass (including cigarettes) have been shown to have causal links to lung and scrotal cancer and implicated in ischemic heart disease and chronic obstructive pulmonary disease Have you a cite for that? Recent publications suggest over 30% of particulates are a result of combustion of wood, what is missing is that they are probably not contributed from modern stoves correctly burning dry wood.

I can see a few reasons: 1) we are burning gas at an alarming rate and it was intended that building regs would deprecate gas connections for new builds by 2016, what the current situation is I don't know. 2) Most of us on this forum burn wood because it heats our homes cheaper than other fuels. Granted this is not true for most who buy logs as a luxury item. Since the demise of the pulp mills wood burning has provided an economic outlet for forestry. 3) It is possible and practicable to burn wood acceptably cleanly

First step, after making sure the electrical connections are making good contact, would be to check the pressure the pump reaches and whether the pressure relief valve is opening too early. Getting a new pump and reservoir is easy enough but you're limited by how much current you can provide at 12 Volts

Is that a question or rhetoric? You cite a couple of accidental sources which no one can have control over whereas there are a number of ways planned and regular woodburning could be controlled, though for now I think it will only be new installs that are affected and maybe larger producers of firewood (who already are likely to have a vested interest in sales of kiln dried wood). How many of us still remember the plumes of smoke rising from cereal fields in July-August prior to 1993?

Piece of string but in general yes because the excess air cools the flame, which is why a bonfire always has a plume of blue smoke even when burning well. When I started even in our affluent bit of the country bonfires were the norm, ten years later chippers began to appear and by 1990 they were ubiquitous. Now most home owners wouldn't entertain the idea of allowing one to burn on site yet, subject to amounts and not creating dark smoke it remains legal. In much the same way cigarette smoking in buildings first became frowned upon and then banned I wonder if a diesel chipper left on high idle will start attracting comments.

That's because you consider wood at 20% moisture content being the only way to burn cleanly. In fact if you keep the combustion temperature up and allow the flame to burn out without quenching then you can burn greener wood cleanly. The advantage large scale burners have is that the combustion can take place well before any heat is lost from the flame and before flue gases reach a heat echanger. On a smaller device the stove walls are often the only heat exchange surfaces, when they are only metal boxes the flame has little chance to complete its burn before it comes into contact with a col metal surface. This is why more recent designs have firebricks to increase firebox temperature and often pre heated air but the small size alone means heat losses per firebox volume are higher than large devices. So as one of the larger heat losses in a fire is from vaporising water it makes sense to minimise this loss to keep combustion temperatures up, hence the requirement for 20% mc wood. I don't know what other techniques will be necessary to meet the new ecodesign standards but it looks like HETAS will only be allowed to sign off these ecodesign stoves so simple stoves will no longer meet building regulations let alone the old DEFRA exempt stove category.

I doubt it's adjustable, the engineer also probably got his terminology wrong and should have said force rather than power. With a multistage ram the piston area of the first stage is highest, so as force equals pressure times area there is more force produced by the first stage than latter stages, with necessarily have smaller pistons and areas.

It may be easier to replace the lot https://www.ks-international.com/isuzu-4x4-and-truck-parts/isuzu-4x4-parts/isuzu-pick-up-parts/isuzu-d-max-tfs86-2-5td-2006-05-2012/clutch.html

Possibly worn master cylinder seals. This won't show a leak as the fluid returns to the reservoir. Symptoms include the clutch gradually engaging when in gear and the pedal down. Also a vigorous stamp operates the clutch but a gentle push doesn't

I'm so used to seeing P schweinitzii on pines but your L sulphureus identification makes more sense if it's on yew

Thanks for the correction, is the tree actually a yew?

A good point as even if its's not chipping it's moving a lot of air and that takes power. In fact a petrol engine at peak torque is more efficient than a diesel, it's less efficient when idling so run in batches rather than kept dribbling bits in should be better fuel use.

http://en.oregonproducts.com/pro/products/bars/prolite_bars.htm is one at least that is slightly ambiguous as it lists replacement sprocket kit under features where it should probably add "available"

It looks like a young dyer's mazegill, Phaeolus schweinitzii, common on older scots pine

Here is a picture of trees in our high street which were shredded up one side and topped quite a few years ago. I don't know the whys or wherefores about the job but it looked stark and ugly for a long time. It still doesn't look good but I'm surprised how the greenery from branches on the untouched side has grown through and softened the appearance. Were I the owner and given the house is just behind the trees I would have bitten the bullet and had the lot out as they are to the south of the garden .

I very much doubt it, the chances of the flywheel being close enough to still run after it has sheared are minimal. If the nut is tight and you can still see the key and it runs it ain't broke. The key is not what holds the flywheel in position, it just locates it and it's the taper and nut that fixes it. This is why you can file some off the key to advance the ignition and it doesn't affect the hold.

Not of suing anyone with PI for negligence but a bit where an insurance company defended a claim, and lost, at great expence.