Ökofen boiler: pellet filling?!?

[Quito01]

Hello
I have owned an Ökofen wood pellet boiler since 2007 and I have a lot of problems with stuffing with pellet dust which blocks the operation.
It was initially a PEK 15 condensing model with a 3,5 t S220 textile silo and a worm.
The worm was regularly blocked due to the dust released by the granulate. In addition, a large number of breakdowns following "smoke winds" error messages.
I ended up replacing my silo with a new textile model of 7t KGT2620 and a vacuum feeding system.
The improvement was notable but insufficient for jams. The condensing boiler being too sensitive to weather variations, it was modified in 2016 with a return to a standard model.

I changed pellet suppliers several times for the same result. I was told that my silo (under a shed sheltered from the rain) was too sensitive to humidity, which explained the dust. I have since made a complete cladding of the silo.
It's better but I still have these jam problems. Now it is rather in spring at the end of the silo. 3 episodes in 2020.

The last yesterday with a very dense pile of sawdust in the hopper and a blocking of the underlying belimo. The screw under the hopper was full of dust and I had to break it up with a drill. The belimo valve was stuck with gum (melted granulate?).

In total I find this situation very annoying and the local manager of Ökofen is content to incriminate the granule.
However I have already changed supplier and the truck is adapted with a slow filling speed (but I can judge it).

Has anyone ever encountered such a situation and would they have a solution to offer me?
cordially

Quito01

PS: the granulate is Piveteau DIN +

IMG_0098.jpg (106.95 KB) Viewed times 30656

IMG_0097.jpg (112.37 KB) Viewed times 30656

[taam]

Hello Quito,
No jamming problem because of the "thin" on mine. (non-condensing model - aspi - since 2012)

I am surprised by this description of rubber in the belimo.

Personally, I would start by determining the humidity of the granules (to be taken in the daily silo after aspiration - Microwave method).
Note that at first glance, the granules must be hard and not brittle when tightened in the hand.
(I have the impression on the photo, of a dark sawdust, as if it were wet?)

[Quito01]

Good evening
Thank you for the answer. the regional manager blames a return smoke to explain the "gum" aspect of the granule.
For the humidity test I will try the microwave test but I need to obtain a precision scale.
The granules are hard and the sawdust is not damp to the touch. The silo is under a shed and clad, so no worries.
By cons sawdust is present ++ C is my main problem. It is a pity that they did not find a sawdust trap with a vibrating sieve and a collection bin.

[Did67]

I also have a PESK15, since 2008. My silo is self-built with OSB on a wooden frame, with V-shaped bottom and extraction screw, then taken up by suction.

I had only once a blockage of the silo bottom screw. I understood afterwards: I was not emptying. I refueled. On the side, granules had accumulated with each year, the fines that were added to it. And one year, colder, this part "fell" a bit like an avalanche. Result: screw stuck.

The condenser is "boring" because indeed, when it clogs, the pressure sensor puts the boiler in fault. Every year I clean all the turbulators, which are not easy to remove. I made myself an "extractor" = a self-locking pliers to which I fix a steel cable with a weight. I pinch the turbulator then I give small jerks and it comes quite easily. This invention dates from this year - until then, it was a hassle.

You obviously have a problem with the quality / holding of the pellets. Already, they seem short (breakage?) ...

I have not been to see the valve controlled by Bélimo ... I do not know what it looks like at home.

[Did67]

By cons sawdust is present ++ C is my main problem. It is a pity that they did not find a sawdust trap with a vibrating sieve and a collection bin.

Start by measuring the sawdust rate ... With a sieve. There must be less than 1%.

[taam]

the regional manager blames a return smoke to explain the "gum" aspect of the granule.
For the humidity test I will try the microwave test but I need to obtain a precision balance.

Yes, I am afraid that the problem is the Bélimo which does not close correctly any more, from where an abnormal return of smoke through it, via the screw burner, during the aspiration. This may explain this gum formed by "smoked" sawdust.
Again ZERO blockage at this level on mine with a sometimes huge sawdust rate (50%?)

We must already verify that
1) the Bélimo spring brings its index back to 0 (as soon as the burner stops)
2) the valve is then well closed, sphere not burnt and sealed.

Bélimo on mine: motor with its index (1) valve (2)

[Did67]

I share this opinion ...

Indeed, if once it got stuck, little by little, it will get worse ...

It is advisable to remove the cover and ... to observe, indeed, if that returns well to zero. It may be that the spring is tired (the opening is electric, but the closing, for safety, it is the spring - like that, in the event of a power cut, the fire cannot go back up in the silo. .).