openspaceman

Yes you need to cool the saturated air below the dewpoint. Yes but the reason is that all the heat of the condensing water is being lost to the wall plus the difference in temperature of the kiln is also driving heat through the uninsulated wall. To be efficient the kiln needs to draw dry air in, heat it up so it can absorb even more water and then dump it outside at as near ambient temperature as possible. With a dehumidifier you form a cold surface onto which the condensate settle and dumps its heat of vaporisation into the refrigerant which is then compressed back into a liquid at a higher temperature than the kiln, i.e. it gives the heat back into the kiln at the cost of electricity to run the device. The alternative means, as I suggested and Renewable John, uses, is to suck in a small amount of cold dry air and pass this via a heat exchanger in contraflow with warm saturated air leaving the container, so the only heat (apart from losses through the insulation) leaving the system is in the vapour in the saturated air dumped outside. Now your bare wall idea could form a cheap heat exchange surface if the insulation was replaced against the inside surface of the wall with a small gap but closed at the bottom with a row of holes to the outside at the bottom .With a similar arrangement for the outside but holes into the container at the top with a channel at the top into the container to prevent the internal flows short circuiting. It would work by the small portion of the circulation in the container being bled down the wall and then vented outside to waste with a drain for condensed water. The incoming cold air would be sucked up the wall and gradually pick up heat from the wall until it entered the main circulation warm and dry. This would be for a recirculating system, straight through systems can also be efficient but more suited to lower temperatures.

It pays the bills even if the work is a bit rough and probably attracts people that are not interested in arboriculture. With work in less than ideal conditions, often in the dark, and the amount of discarded ironwork lineside with trees growing through it it is very difficult to avoid mud and small bits of ballast going into the chipper. In 6 years I have been aware of 3 clips accidently going into chippers. The Jensen took the worst damage needing flywheel machining back in Germany, 1928 broke a disk or 3 but appeared to suffer no other damage and the Heizo hack 6 30 broke a blade and was back working the same shift.

Clinker= fused ash it often happens with contaminated wood, dirt often causes this. What happens is the fire is not normally hot enough to melt wood ash but if other contaminants are present, like chalky soil, the ash melting point lowers and the ash turns to a liquid glass which then solidifies on cooler parts.

Sorry Skyhuck, I got the name wrong, senility setting in as another year of my life passes by EL-USB-2 | Data Loggers Depending on how the flow goes in the kiln you can either log temperature and RH either side of the pile or just treat the kiln as a black box and log air in (before heat recovery), kiln temperature and air out (which is probably a surrogate for kiln temperature. From this you can calculate the increase in moisture to the air from the wood. The check log should be split in half and one half microwaved (carefully) to get the oven dry weight and hence the original moisture content. If mixed species you may need more than one. From this you can calculate when the check log is dried to a given mc. I write date and time plus mass on the log with indelible ink and do an excel sheet later. The same things can check the efficiency of heat recovery.

How about a lascom data logger on the input and output, this with a sample log which you can weigh during the cycle and you would have good empirical evidence of efficiency.

There must be something else wrong then. Mind I've had a stand up row with a fitter who swore blind he had sent out a gm1928 with fresh discs and they produced chip like this, yet with genuinely sharp disks it produced a good sample. One of the things about modern chippers is that they continue to chip and load when blunt but it increases wear and tear. Having said that there is no reason that chip will not feed given suitable equipment.

Same to you and all Cornish At 30% mc wwb shouldn't it top out at about 42 tonnes? Do you mean the feed to the stoking auger is a walking floor or that the grate is a reciprocating walking floor? We had this latter on the Kobs with the feed controlled by 2 light barriers, the first to sense when the feed was too low and the second to sense the leading edge of the heap and stop the feed. A third over the tail end of the grate sensed ash build up and started the de ashing auger. I loved working on these and snagging the installations, it was always out of spec fuel or the fuel store that caused problems and yes I also had a long shard jam in the light barrier tube and cause a burn out. I wish I were still involved in the business. We didn't have any inclined augers (except in pellet stoves) but still managed to snap the drive chain and eventually auger shaft on a 500kW because of fines jamming the auger.

I think the flows would be to hard to plumb, normally the drum is a closed circuit with one side of the heat exchanger and the cold air in and warm air out are an open circuit outside. For the kiln you want the warm air back in the kiln and cold saturated air dumped outside. A small dehumidifier is about 150W and can condense out around 10 litres of water in 24 hours at a cost of around 3.6 kWh(e) if the op is running 30kW delivered into the kiln that could be shifting as much as 40kg of water an hour. It all becomes a balance between temperature verses cost of airflow and if splitting, case hardening and distortion aren't a problem tends to point to higher temperatures being most economic.

The chip looks like the blades were blunt, as you say the ragged ends give the heap a negative angle of repose, a cavern will form and does under a sweep arm too. Yes I've seen this too as the auger trough enters the square tube. I'm wondering if a vibrating conveyor with 50m holes would allow in size chip to drop through and shards to carry on off the end, for manual loading or rechipping.

Do a search on whole house heat recovery unit. They are pricey. You can recover small air to air heat exchangers out of condening tumble dryers. The idea is you bleed off a small amount of the warm saturated air from the kiln and pass it over a heat exchanger that brings in the cold dry air from outside. Water condenses on the cold surface and the heat from this is transferred to the incoming air. It should be practical to make ones own with a long box, dowels and cling film.

I had the same problem when I put a powerpack on the sawbench, basically the pulleys have to be so large a diameter for the belt to take the torque of any large pump that it's impractical without multi vee belts. Having said that the Ahwi had Vee belts and that delivered all the 400hp.

why not? It's a source of clean heat and all you need is the heat to supply the latent heat to change moisture to vapour and a means of circulating it. Air drying is probably the mos economical but it becomes a toss up between cashflow and cost of dry storage verses capital cost and energy use for the dryer. To dry from green 50% to oven dry will cost about 30% again of the energy in the dried wood plus running circulation but it's not worth going below 20% as dry wood picks up water from the atmosphere. We ran a number of experiments on various scenarios when designing a dryer for our client and one which showed promise was a directly fired batch sequential one that dried in 3 days but wasn't adopted because it would have been too costly to certify the burner, which appeared clean and burning with about 30ppm CO.

Absolutely nothing wrong with caution. I would be interested in knowing which pictures on here have position in their exif data, especially any of my own!

I wouldn't consider a boiler burning 4 tonne/week small. The biggest I dealt with was 1MW and running a department store and that didn't manage 20. I wonder if there are estimates of the split of home grown biomass consumption between large installations and little stoves in homes only burning a couple of tonnes per year. How do the longer bits stop yours? they generally don't jam my 150kW one but tend to lift a safety flap whish causes a burn out. Mine constantly short cycles because of insufficient load.

If you look at the neutraliser you will see it is really a small accumulator so if you have a non scheculable i put like solar or wind or a peaky input like a batch fed boiler you may as well go for the extra capacity of a heat store. If you have space.

Point of order; Peter Read coined the word biochar for char used as a soil amendment and to sequester recalcitrant carbon for millennia as a means of removing excess CO2 from the atmosphere and surface waters of the sea. I think the reference was to biocoal burning in the stove.

Why an arc for height, to show targets? Is the polygon of 4 compass points for crown spread simple or do you use interscting arcs from the stem? Does the rpa follow similar rules to the old NJUG10? It looks like a simple spreadsheet based on the xy coordinates could generate the above into a mapmaker layer and shading done by a style number based on the category.

One can sometimes see a sign of star shake in the bark but I've not seen any evidence of ring shake showing in the bark. Ring shake is often in larger butts of sweet chestnut, normally present after the bark has chequered, younger fast grown trees with smooth bark are normally ok. Often with older butts the ring shake is in a cone and can appear to be sounded out by cutting rings off. striking a narrow ring to split it and looking at the split surface will often reveal a greyness showing an undetectable de-lamination.

It was a typo, I meant BS5837. I was wondering what was needed in a mapping program to satisfy BS5387 so I could see if there was another way of doing it in mapmaker. Once the centre of the stem is plotted is it a matter of working out the dripline or root protection area or is it also necessary to work out shading?

They'll make your wrist ache, we used them for spot weeding mostly. To kill trees standing we would frill girdle them with a hatchet and then squirt roundup in the frills, no point going deep as its the cambium that trans locates the chemical.

Would you explain the functional requirement of mapping for BS5834?

We used these Drench Guns - James Country Supplies 30 years ago, nowadays it's a Stihl bt45 and (exorbitantly expensive) eco plugs for broadleaves in general.

It already is, as long as the premises is registered as a hazardous waste producer and you have 500 litres waste oil firms will take it for free and sort out the consignment note.

Bespoke software Eric did produce a utility for me to convert some files and didn't charge

I don't know, I've only used it for triage inspections for railway and my background is forestry (management plans etc.) so I'm not involved in the preparation of building site plans, just watching the guys once the work is awarded.