openspaceman

You've hit a couple of nails on the head there, Sweep auger systems under the hopper are a pain it the backside although they are cheap and suitable for grain or pellets.. They always fail when the hopper is full. Points of failure are interesting, the original models I dealt with used the auger to provide power to the gearbox for the sweep auger in the middle. After the auger jams a few times it gets out of true and over then next few weeks gradually fatigue fractures. Welding it up just makes it more rigid and it fails even quicker. The reasons I have seen for the auger failing are also interesting and, to me, counter intuitive. The obvious one is slivers bridging the flights and then being carried forward on top of the auger to be impacted into a mass at the auger exit. G30 specifies no slivers over 100mm and presence of these loses you any warranty claim. The one that confused me most was some dry woodchip from a joinery firm which was dusty. With high mc chip dust is not a problem as it sticks to the bigger chips but in this instance as the silo emptied and was regularly topped up the dust gradually worked its way to the bottom and settled on the bottom of the auger trough where it compacted. As this layer built up the auger ran on it but was bowed upward until it jammed on the top side of the trough and brought the system to a halt with initially a motor thermal trip and later as they fooled about with the current overload sensor, snapping the drive chain.

The difference is largely down to capital cost. The woodchip is fed into the boiler concurrent with the air supply so easier to get the combustion rigt. Very hard to get chips to a G30 W30 spec, even if the supplier tells you it is. Much easier to stack and dry cordwood.

I used straight OSR from the grocers from about 1990 till I packed up proper work a few years back. No problems except maybe a perceptible increase in bar wear. A chap who went to university after cutting for some years did his thesis on veg oils and basically told me to go for the cost saving of ordinary cooking oil. Big problem if you park a saw up with it as it oxidises on the chain and the saw grows green fur. When I started it was common practice to use sump oil and we hated it as much as the arbrex. It is also definitely implicated in scrotal cancer, the first known industrial cancer which was identified in young chimney sweeps, a resurgence occurred in the US and was traced to young mechanics putting oily hands and rags into their pockets. Benzo(a)pyrene is a product of incomplete combustion found in soot, tobacco smoke and sump oil.

I think you have that right, I hadn't realised Laddomat was a make of back end protection. Yes they work just like the thermostat and water pump on a car engine, if you take one apart, as I did with one of a different make, you will probably find the waxstat looks just the same as the one from a car. All the time the water in the boiler circuit is <60C it circulates it back to the boiler return, as it gets toward 60C the waxstat opens and a small amount of hot water is directed to the heat load, with a similar small amount of cold water blended into the boiler return. When all the boiler circuit and the return circuit is above 60C the waxtat is open fully and it then blocks the recirculation to the short circuit to the boiler retuirn. In larger installations the valve and thermostat are all electric. It's not an uncommon problem and I have experience of a complete talbot C150 install where this vital back end protection was left out. The client became so disillusioned that they had scrapped the boiler after 3 seasons because the firetubes were fouling with tar, poor woodchip aggravated this, before I could advise them.

I have the G9 and don't trust Canon because it has died because of a generic fault with loose screws shorting the DC board. Geotagging is not a big issue if you have a smartphone or gps device, make sure the gps is on and has lock, either synchronise the camera and gps or photgraph the time on the device and then use software like gpicsync to tag the files.

It was a regular thing before chippers became ubiquitous, turf up a bit of rough grass, burn arisings, go back and rake ashes next day and if cool replace turfs. not on Tuesdays as that was washing day. He can get an exemption for burning up to 10 tonnes of plant material a day on an open fire as long as the plant material is produced on the site e.g. one cannot bring arb arisings to a yard and burn them. In practice nothing is likely to be said as long as dark smoke is not emitted or

It is about stratification, keeping a hot body of water sitting on top of the unheated water underneath. Water is a poor conductor and as hot water is lighter than cold ( until 4C) there is little heat transfer from top down. If you introduce hot water at the middle of the tank it rises through any cool water above it and mixes as it does so, producing a layer of warm water at the top. If you introduce the hot water at or near the top there is less opportunity for mixing and the top remains available to draw off as hot water from the top.

I doubt it will be a problem, the systems I worked on used solar thermal to heat the top of the tank for DHW so it was important to keep the top of the tank as hot as possible with the little contribution available, so the last this you want is to allow it to diffuse up through less warm water. I imagine the heat input from your boiler is significant compared with the size of tank. Ours was at best 25kW(t) into a 3 tonne tank. In the event they plumbed the underfloor system in wrongly and quickly destroyed the stratification, problem was compounded by having the DHW plate heat exchanger pumps only set to trigger as long as the top of the tank was above 50C, leaving 12 flats with no DHW. Housing association staff were the dumbest set of jobsworths I ever came across, no concern for their tenants.

The tank capacity needs to be the pump output in a minute, any less and oil cooler needed. Also needs to be taller than wide with the return under the oil surface.

I've got the Mk 1 from 76

I wouldn't expect any to survive oxidation in the fire. I also wouldn't advise anyone to be in the back of an enclosed truck with laurel foliage being chipped into it, though I have heard no incidents of poisoning from it. Crushed laurel was used by entomologist to kill insects in jars.

I cannot remember but probably one of Oliver Rackams books

Yes this is the hydraulic motor running a cage which clamps down between the wheels, never seen it but the big drawback with mine is the tyres being marked not suitable for highway use. The original timberliner from the 80s was pto drive to a driven bogey, a lorry drum brake varied the drive ( as a clutch) which the driver modulated from the cab, largely to prevent the trailer jackknifing the outfit. It was quite impressive and with a big tractor was more capable then a lot of forwarders available at the time ( which tended to be ~150hp). It lacked all the other attributes a purpose built machine has over an agri based outfit and was heavy.

Or was it that generally animals were not allowed to graze in churchyards, were often herded rather than folded or enclosed, and yew is poisonous. Yew woods were the province of the monarch even though by tudor times most bow wood was imported.

Yes and this retting step was similar to how linen fibres were extracted from flax ( frown for seed aka linseed).

For England I thought the low point was after the iron age and pre roman occupation. One of the attractions of south britain was that it was good arable land for export of ceral crops to replace land over cropped and ruined in North Africa.

What sort of cement boards are they? May be best painted and left in place.

One would need to define "better" there is little doubt in my mind that a polytunnel with mesh sides that can be rolled up, as used for lambing sheds is very energy efficient in making use of the solar drying by radiant heat and ambient air. During the summer it will dry split logs in a few weeks if the airflow through the stack is homogeneous. As I said drying logs to their fibre saturation point can be quick given the right conditions and poking in enough energy. Delivering energy is the key because you always need 0.7kWhr of heat to turn a kilo of water in wood to vapour to be carried away from the surface and in practice you have to be very good to do this with 50% efficiency. Cash flow and profit may dictate something else, consider a large commercial log producer selling into retail stores in bags with a sophisticated production site. He buys in suitable firewood at between £30-40, splits and packs it for £10 and gets £750 for it when the retail chain wants it. He can process fast enough to match demand but that's only really between November and January. Does he process an average amount throughout the year and store material in a large shed or is it worth going "just in time" using casual labour, lots of energy and no cash flow problem.

You are changing tack too quickly for me. The dehumidifier may not be a bad option and any extra heat will benefit but as I said currently you are wasting a lot of energy through the container walls. I'd go for insulation and keep it dry. Solar passive is great but should be a separate box on the side and configured not to lose heat at night. For the small extra electricity cost active solar with using a black cloth absorber is likely worthwhile, probably better suited to cold dry climates than UK. Unlike drying planks you don't have problems with checks and splits but you tend to have greater cross sections and there in is the limiting factor. The 19 gram piece of ash I took and hung in this study this morning has already lost 4 grams because it has a large surface area to lose moisture from and a small distance for the moisture to migrate through. As a log gets bigger this ratio gets worse and drying slows down. The only thing that speeds it up is temperature. So you have a complicate equation to work out, firstly to supply enough energy to evaporate the total amount of water you need to remove per hour, then the necessary airflow to carry this water away, and the power to drive it and then the amount of log surface area you present to the airflow. The more logs you have to blow through the higher the back pressure and more electricity used. This tends to mean that fan electricty is the highest cost as low grade heat is cheap, which is why the Border Biofuels chip dryer ran air at about 40C, it was designed to use waste engine heat. I've got a feeling its not worth blowing air less than ~25C and you get much more useful work at higher temperatures, so insulation is a must. The dehumidifier has the great advantage that the latent heat of evaporation isn't lost to the outside air as is with a through flow dryer but I'd like to know the inlet temperature and outlet temperature plus water condensed to see how efficient it was.

OK this is getting too far off topic, I'm happy to take this to a more suitable forum or e-mail but I will comment: Yes it does increase the price of electricity and yes it was a huge incentive which did not take account of the changing costs of solar PV but the cost of failing to have enough installed PV would have been of a similar magnitude. Not having sustainable energy is rapidly becoming a non option especially since pan european public opinion has changed post Fukishima. There is no way the wealthy are willing to have a fairer tax system which is why we are seeing the demise of the NHS. We are governed by wealthy people who believe in the market economy and no limits to growth. Economies depend on success not also rans or lame ducks because capitalism mimics darwinism. Society tries to keep it within bounds. Wealthy people also avoid tax better than most. I've snipped the rest of your post which contains some misconceptions but is too far off topic for here. Have you read Mckay's book "sustainable Energy Without Hot air" it's a no cost download , some very heavy going but well worth trying to understand, I admit much of the maths was beyond me, especially the stuff about flight.

Not at all, though I would be interested in an experiment on the equilibrium moisture content of a 23% mc wwb log in a shed on a rainy cold february. You haven't really given enough details of what cost benefit you are aiming for. Usually the only benefit of drying is to meet a standard or charge a premium. If the latter then you have to cost the operation to see what the premium is. In general firewood is a luxury good and the price paid has little relation to to its competitiveness with other available fuels. Having a product that is easy to light, has a lively smokeless flame and doesn't pollute may justify the cost and secure the premium. On the other hand a large industrial consumer will stomach the ~10% flue losses of burning green whole tree woodchip because the double handling alone doesn't justify a drying stage and he's only paying £25/tonne delivered. Having said that early in one of the NFFO rounds one biomass burning power station ran a big grain dryer with and extra oil burner to get the wood dry enough to cofire with coal because the subsidy was so high.

I cannot help but we had one as a loader tractor on the second dairy farm I was employed, strange thing with a hand clutch and a foot clutch. Anyway I think it was the same engine as the 4 cylinder MF 35 before they changed to the much better 3cylinder perkins.

That's quite a high starting point for ash, it's notoriously difficult to give a general rule for a species moisture content and it can vary between parts of the tree. Anyway to get where you want from 38% to 23% from an initial tonne you need to lose about 200 litres of water. There's still not enough details but a couple of points, the recirculating air affects how saturated it becomes. Theoretically you maximise use of fan power when the air leaving the wood is saturated. At saturation air holds different amounts of water according to its temperature and it isn't linear. Without going into detail if you draw a graph of absolute humidity verses temperature at saturation you will see there is a point around 25C where the moisture carrying capacity starts kicking off. Below this and you have to pay to circulate a lot of air for no great drying effect. A chap posting here on another forum gave some useful figures which illustrate this: http://arbtalk.co.uk/forum/milling-forum/38987-kilning-theory-discussion.html#post610301 And this sort of chart contains a lot of useful information if you take the time to figure it out. http://upload.wikimedia.org/wikipedia/commons/0/05/PsychrometricChart-SeaLevel-SI.jpg From this you can see that it your container is uninsulated in a british winter the ~ 20 degree difference is losing you a lot of heat. This has a knock on affect on your dehumidifier, which is really just a heat pump that recovers latent heat from the circulating vapour and dumps it back into the container but the container loses most of this recycled heat because it isn't insulated... Aloso then consider the COP of the heat pump and compare the cost of electricity to drive it with heat from other sources.

I haven't followed RHI recently but as originally proposed the installation will need to be independently assessed and this will include appropriateness. Then the feed in tariff will be paid for so many hours at one rate and the rest at a lower rate, for a maximum of ~1300 hours. If you consider the cost of the equipment, which unlike solar PV is unlikely to fall substantially, and the fact it will have to be new, from a recognised manufacturer and fitted by a certified person there is no great incentive. It has however made secondhand chip stoking boilers rather cheap.

Are you talking about the Renewable Heat Incentive Feed in Tariffs? These will be paid from the exchequer. It's the solar PV and wind generated electricity that are paid from a pool collected by Distribution Network Operators via the Climate Change levy on all fossil generated electricity. No point ranting about it because the over generous incentive was necessary to attract installation of solar pv (in particular) in order to avoid an EU fine for failing to meet our renewable obligation, the fine would have exceeded the cost. As it is it attracted carpet baggers and the government over reacted and cut it off too sharply. We pay for the government so it's a bit semantic.