kiln dryer

[Lancer]

Which woodchip boiler do you have ? Whats is the capacity of the boiler and what is the size of the water jacket around the boiler ?

 

It is Herz Firematic 199 KW. From rural energy, off top of my head not sure of size of water jacket, I'm not massively technical. We got it in on last day of top rate tariff. So have ran it for a year and it has hardly missed a beat so far.

[Duffryn]

It is Herz Firematic 199 KW. From rural energy, off top of my head not sure of size of water jacket, I'm not massively technical. We got it in on last day of top rate tariff. So have ran it for a year and it has hardly missed a beat so far.

 

Nice boiler ! I would double check with your installer but given that demand for the other heat uses on the site will be minimal during the warmer months then your existing setup should "walk" handling a 100kwh kiln.

[Lancer]

£60 per tonne assumes you are buying green wood, seasoning it and hiring in a chipper ?

 

Assuming above assumption is correct re cost of fuel then Woodchip at 30% is c 3500 kwh per tonne. Boiler will be max of 90% efficient so 3150 kwh per tonne or 1.9p per kwh.

 

I buy in woodchip from a friend currently paying £85 per tonne for chip at 30% get walking floor lorry with 18 tonnes approx at time. We average 58000 KW from 18 ton so 58 divided by 18 gives us 3222 KWH per ton so numbers virtually same as mine.

[Duffryn]

I buy in woodchip from a friend currently paying £85 per tonne for chip at 30% get walking floor lorry with 18 tonnes approx at time. We average 58000 KW from 18 ton so 58 divided by 18 gives us 3222 KWH per ton so numbers virtually same as mine.

 

You have got a bargain there ! My costs are not dissimilar using my own wood ( allowing for cost I would have sold it for) and having it chipped

[Lancer]

Nice boiler ! I would double check with your installer but given that demand for the other heat uses on the site will be minimal during the warmer months then your existing setup should "walk" handling a 100kwh kiln.

 

Cool I will find out for you when back in the office Monday. Demand for heat virtually dies in summer so hopefully we could be in business here. We have lots of space to dry logs naturally so I would probably dry them naturally to 25 % or so then finish in the kiln. 2 Day drying time ok you think or is that optimistic? 16 m3 in a kiln for few days adds a good £20 premium per m3 to the end product so numbers work and we have big demand for kiln dried currently

[Lancer]

You have got a bargain there ! My costs are not dissimilar using my own wood ( allowing for cost I would have sold it for) and having it chipped

 

Yeah its a good price and fairly good quality to be fair. If it got much more expensive then I would probably chip my own wood but this is best as I do not want to tie up one of our barns to store chip, better to use to dry logs

[cornish wood burner]

£60 per tonne assumes you are buying green wood, seasoning it and hiring in a chipper ?

 

Assuming above assumption is correct re cost of fuel then Woodchip at 30% is c 3500 kwh per tonne. Boiler will be max of 90% efficient so 3150 kwh per tonne or 1.9p per kwh.

 

Current chip is low 20s and that probably cost a bit less than £60 if you are splitting hairs.

You didn't mention boiler efficiency in your original comparison so wouldn't the energy from oil cost be higher as well?

[Duffryn]

Cool I will find out for you when back in the office Monday. Demand for heat virtually dies in summer so hopefully we could be in business here. We have lots of space to dry logs naturally so I would probably dry them naturally to 25 % or so then finish in the kiln. 2 Day drying time ok you think or is that optimistic? 16 m3 in a kiln for few days adds a good £20 premium per m3 to the end product so numbers work and we have big demand for kiln dried currently

 

It gets harder to dry the lower the m/c. There is also an elapsed time to get the logs heated up in the first place ( hence the importance of keeping the heat in the kiln 24 /7). If you are putting them in at 25% I would estimate 24 hours to get to 20%. Personally I think a better use of the kiln would be to dry green wood from scratch. This would enable you to free up cash tied up in stock and yard space and would involve less handling.

 

If you want some pointers on kiln design, pipe work and control setup then let me know. I can save you a fair few ££'s and a great deal of headache pointing you in the right direction and the Arbtalk Childrens Trust charity would always appreciate a donation !

[Duffryn]

Current chip is low 20s and that probably cost a bit less than £60 if you are splitting hairs.

You didn't mention boiler efficiency in your original comparison so wouldn't the energy from oil cost be higher as well?

 

Oil boilers are typically 95%+ efficient. My comparison was broad brush and designed to show that Oil doesn't pay when the RHI is paid on biomass .

Edited January 2, 2016 by Duffryn

[Lancer]

It gets harder to dry the lower the m/c. There is also an elapsed time to get the logs heated up in the first place ( hence the importance of keeping the heat in the kiln 24 /7). If you are putting them in at 25% I would estimate 24 hours to get to 20%. Personally I think a better use of the kiln would be to dry green wood from scratch. This would enable you to free up cash tied up in stock and yard space and would involve less handling.

 

If you want some pointers on kiln design, pipe work and control setup then let me know. I can save you a fair few ££'s and a great deal of headache pointing you in the right direction and the Arbtalk Childrens Trust charity would always appreciate a donation !

 

Yes i will be in touch on this with you. I would be very happy to pay you for your time and input I think the saving on price and hassle would be big and also a donation to Arbtalk Childrens trust. Your advice so far has been very much appreciated.