jrgatelogs

I agree with @Woodworks that a dehumidifier won't be effective.
 
The reason I asked if the RH of the outlet air was tested was to see how close to saturation you were getting, the aim is to get to near 100% saturation at the lowest temperature you can get down to.
 
For example ( and I'm picking these figures from thin air one would have to consult psychrometric tables to get real numbers) it's 15C where the kiln is and the air going in is at 60C, the air coming out should be around 20C and 95%+ RH. If the RH leaving is lower it means the air is not in contact with enough log surface and hence is not picking up enough moisture to be efficient, similarly if the exhaust temperature is higher then not enough of the heat input is getting into the logs.
 
I used to use earlier versions of these
 

Temperature and Humidity Data Logger - EL-USB-2

WWW.LASCARELECTRONICS.COM

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Temperature and Humidity USB Data Logger  

It probably needs more recirculation within the kiln and maybe smaller logs. Have you measured the outlet air for moisture saturation?

I haven’t! I open the doors for a few minutes each day to let humid air out! I wondered if a industrial dehumidifier would assist and have it run a few stints each day for an hour or two!

To test the humidity do you have to purchase a humidity gauge of some sort?

In that case I wouldn't worry as the pressure from the fans will far outweigh any difference in buoyancy of moist air and it may be that heat is better conserved because as the warm air picks up moisture it cools and cooler air plus water vapour will fall even given water vapour is lighter than air normally.

8 hours ago, openspaceman said:

I'm not familiar with these kilns but is there not a fan blowing fresh air into the kiln?

Yes. There’s 4 fans behind the radiator blowing fresh air in but the vents are at the bottom of the kiln which seems odd as surely the moisture would be better vented out at the top? 🤔

Hi all. Sorry I’m late on this topic. We have a couple of Glen farrow kilns. A flaw I’ve found is the vents at the bottom by the doors, I’d imagine they would be better at the top to release the moisture once it’s circulating in the air, otherwise it will just blow about in the top of the container and as soon as the kilns cool overnight the ceiling is covered with moisture. Even running it 24 hours I can’t see how the moisture can escape. I was wondering about a industrial dehumidifier on a timer to just come on for a couple hours 3/4 times a day to pull out the moisture. At the hottest point we get to 45/50 degrees this time of year, up to 60 in summer. I’m no expert but I imagine if there’s enough heat to get to the centre of the logs, and some way to get the damp out it should dry. 
i know I’m late to this, so if you have built something could post some info and photos please? 

That’s where we fill our 350. It’s a pain to fill where it is. We filled a 20 litre drum with oil then took the 205litre pump to the machine with an adapter to 20mm water pipe to get it in. There’s no breather so if we fill it right up we take the sight glass out to let air out. Careful though when you put the sight glass back in and pump more in as it will pressurise and blow back, so just put a bit at a time in [emoji106]

Can you post some photos of the set up please? In summer I can run the standard set up all night but this time of year it’s a no go

On 08/02/2022 at 14:38, Chalgravesteve said:

It is also almost impossible in my view to try and maintain the water temperature in the water jacket/heat exchanger system by regulating the heat of the burn in a GF Boiler (or my Dragon for that matter!) The burn will go through various phases of heat, but once it escalates hotter than 80 degrees, you are heating a small amount of water with a great deal of heat and very little margin for error. The last thing you want is a water overheat and a boiler still burning as that is bloody dangerous. 

 

I am assuming that you have an upper limit of water temperature in the system of 80 degrees beyond which your automated processes should be shutting down the burn as much as possible as you are in danger of having the water starting to boil. Whatever you have attached to the boiler (kiln/radiators etc ) that draws the heat off, cannot be taking more than a few degrees off the water temperature in the circuit, so it is really easy in a small, low volume water system to cause an overheat on the water. 

 

So it is far easier to operate an accumulator tank system, which means that the upward change in water temperature is far more gradual and enables you to shut down the boiler burn and maintain a temperature increase commensurate with the drawn off heat of your kiln/radiators.

 

   

Thanks for that. I think this is what I’m going to have to look at. In my opinion they should of come with a tank as they are impossible to run full time, we weren’t even offered an accumulator as far as I can remember. 
we did have a issue when someone went past the kiln and knocked the switch off the the kiln fan control, so the fan didn’t come on, the water boiled, and started causing havoc so I slowly drained the water out while the system auto topped up but there was damage to the insulation on the boiler, so drained the system, not fully as it turns out, got a frosty night and a pipe in the radiator burst, so got that to try and work out now too. We have two kilns so still got one working. But that’s another subject. I’ll take a look into what it will cost to add an accumulator. Thanks

On 08/02/2022 at 08:33, Chalgravesteve said:

You need a large accumulator tank. I run a 197kW Dragon with a 30,000 litre accumulator. Burn the boiler hard and get the heat into the accumulator and draw the kiln heat from the accumulator as required. Then you can run it all night 

A 30,000 litre tank? Was that quite and expensive install? I wrestle with these kilns so much, tops of my ibc cages dry in no time, the bottom never gets dry, the warm air just goes upwards and above them. 
anyway, I’ll take a look at an accumulator, then will have to look at if we can budget for it. 
thanks

Hi all. So in the meantime while waiting for the scheme for the small producers, we have to sign up to the current scheme they have in place? 

Hi. Just had a read through this topic. Interesting read, these boilers are simple but take a bit of thought to run! 
Do you manage to keep the kiln running all night? I’m about through the day and can keep on top of the boiler but find unless it’s summer and the boiler isn’t having to work as hard to keep the water temperature up, I struggle to keep the water warm enough for a full night. 
Thanks

Might try those. I’ve wondered about a dehumidifier before but there’s vents so thought I’d end up pulling moisture from outside more than in. Maybe worth hiring one to try and see how it helps. 
cheers for the ideas

Hi all 

I’m new to this forum, I’ve been on a few times and everyone seems really helpful.

We have two Glen farrow boilers with kilns. We have run them for a few years now, not constant, just when we have logs to dry. I find the tops of the ibc crates we use to dry are nice and dry within a couple of days, but the lower part of the kiln is cool, and the logs are nowhere near ready. The area between the tops of the cages and the top of the kiln is lovely and warm but it’s useless up there. Does anyone have any tips and tricks! I can get the thermometer reading up to 50 degrees but that must be high up. 
Also does anyone manage to keep them running all night when the weather is a bit cooler? I imagine drying logs would be far quicker if the radiator kept the logs warm as it surely takes a while to get heat to the centre of the logs. 
Thanks