kiln dryer

[Duffryn]

QUOTE: I can dry softwood logs in a day and hardwood in 2-3 days. Add a day to these times for big 50cm logs.

 

 

How do you get such a low moisture starting point for Hardwoods ?

Generally 50-60% is the norm.

 

At that level I would have thought 4-5 days to reach 20%?

 

A constant 60 degree temperature and massive airflow through the container ( I have two heat exchangers on a 10ft container). Beech is the only wood that seems to take a bit longer (another 12-24 hours). I put bigger logs at the back of the kiln, closest to the heat exchanger and the smaller logs at the front.

[arboriculturist]

It is easy to overlook you are running a top spec. chip boiler, maintaining 60 deg. 24/7, whereas most have huge temperature spikes with batch boilers and all the grief that is associated with managing one.

 

Yes I can appreciate 3 days is adequate to produce a quality consistent product with your system design, well insulated.

 

Did HH carry out the installation? I notice their biomass website won't load anymore from the H.mat website link?

 

I can see there is still a model there to economically dry timber using > 200kw/h chip boiler to align with the higher commercial tarrif - hefty investment nevertheless, but practically labour free, hassle free and efficient.

 

With space to stack the roundwood to like Cornishwoodburner to drop the MC and then contract chip, life would indeed be quiet with greatly reduced stress levels all round!

[arboriculturist]

A constant 60 degree temperature and massive airflow through the container ( I have two heat exchangers on a 10ft container). Beech is the only wood that seems to take a bit longer (another 12-24 hours). I put bigger logs at the back of the kiln, closest to the heat exchanger and the smaller logs at the front.

 

Would you not be better with less airflow and consequently a higher temperature?

[Duffryn]

Would you not be better with less airflow and consequently a higher temperature?

 

There is so much capacity on the boiler that I can maintain full temperature even with the heat ecxhangers on full power.

[arboriculturist]

There is so much capacity on the boiler that I can maintain full temperature even with the heat ecxhangers on full power.

 

I see your point - 10ft HQ with two 54 kwh heat exchangers serviced by a 198 kW h chip boiler with a nominal capacity of app. 165kW h.

 

Would it not improve drying times to run boiler at 90 - 95 deg. C or are there fuel efficiency issues as higher temperatures?

[arboriculturist]

It is easy to overlook you are running a top spec. chip boiler, maintaining 60 deg. 24/7, whereas most have huge temperature spikes with batch boilers and all the grief that is associated with managing one.

 

Yes I can appreciate 3 days is adequate to produce a quality consistent product with your system design, well insulated.

 

Did HH carry out the installation? I notice their biomass website won't load anymore from the H.mat website link?

 

I can see there is still a model there to economically dry timber using > 200kw/h chip boiler to align with the higher commercial tarrif - hefty investment nevertheless, but practically labour free, hassle free and efficient.

 

With space to stack the roundwood to like Cornishwoodburner to drop the MC and then contract chip, life would indeed be quiet with greatly reduced stress levels all round!

 

Duffryn - did u see the above message ?

[Duffryn]

Duffryn - did u see the above message ?

 

Sorry - missed that . Yes HH did the installation, since the RHI drop they have stopped promoting biomass installs but still do them if required. Did a cracking job on mine, really really pleased with it

 

Re the temperature question. Heizomat recommend a max of 85 degrees

[arboriculturist]

Sorry - missed that . Yes HH did the installation, since the RHI drop they have stopped promoting biomass installs but still do them if required. Did a cracking job on mine, really really pleased with it

 

Re the temperature question. Heizomat recommend a max of 85 degrees

 

I thought it would be a HH installation - neat.

 

Ooh, 85 degrees C - I didn,t realise that.

 

Stoking a batch boiler and attempting to maintain a constant internal temp. 24/7 with unsociable hours labour shortfalls is an impossible task, as it adds well over a day to a drying cycle. I can see clearly why you didn't personally go down that route.

 

IYO - Does drying 'still' stack up then if you were to commission a new installation with a Heiz. > 200kW h ?

 

I am guessing the Heiz. would be around 70K and 30 - 50 K for the ancillaries - does that sound like a ball park figure?

[Duffryn]

I thought it would be a HH installation - neat.

 

Ooh, 85 degrees C - I didn,t realise that.

 

Stoking a batch boiler and attempting to maintain a constant internal temp. 24/7 with unsociable hours labour shortfalls is an impossible task, as it adds well over a day to a drying cycle. I can see clearly why you didn't personally go down that route.

 

IYO - Does drying 'still' stack up then if you were to commission a new installation with a Heiz. > 200kW h ?

 

I am guessing the Heiz. would be around 70K and 30 - 50 K for the ancillaries - does that sound like a ball park figure?

 

I'm a bit of touch with this and the costs. I think you would be looking at an 8 year payback, so IF the RHI was the main driver, and the boiler was used purely for drying logs it would be no where near as attractive as it was.

 

I would guess £50K for ancillaries and fitting but not sure of current boiler costs

[arboriculturist]

I'm a bit of touch with this and the costs. I think you would be looking at an 8 year payback, so IF the RHI was the main driver, and the boiler was used purely for drying logs it would be no where near as attractive as it was.

 

I would guess £50K for ancillaries and fitting but not sure of current boiler costs

 

Probably this is why I know of knowone in the past 12 months who has installed a Chip boiler and only a handfull of GF Batch based systems at 38K.