Stove explosion pellets. Stove explodes!

[Philippe Schutt]

It also happened on a log insert, the guy had posted on the forum of system D.
The method is effectively to transform your device into a gasifier, through improper handling or equipment failure.
As said above, it is easy with a log stove, and it can also be caused with a pellet stove.
Poorly adjusted or poorly designed pellet stoves can also start up at start-up. We often see a little woum at startup, Edilkamin in particular because their factory settings are too generous in pellets at startup. Another cause can also be too much distance between the candle tube and the brazier. So the pellets smoke but cannot catch. When the start time has passed, we go into error mode, the stove puts the extractor all the way, the fire starts and if the hearth has not had time to be cleared of smoke, boom.
A pellet stove must start quickly, not when the brazier is about to overflow, otherwise there is a problem and also a risk. The installer is or should be made aware, but the manufacturers prefer to keep quiet, it looks bad.

The old Wanders (monteggrappa) also had pressure relief valves, and they were useful. MCZs have a warping area on the door latch that opens rather than explodes.

That said, a clean and properly adjusted stove starts in less than 10 minutes, and does not fill the fireplace with smoke. Annual maintenance is compulsory or strongly recommended, depending on the brand, but they all emerge if it is not done. The technician immediately sees if the start is suspicious.

Suction cups are prohibited, except special stoves and specific connection. But that doesn't change the risk.
Natural draft pellet stoves are in principle also with manual ignition.
Ah, there is yet another cause, it is the use of concentric systems of PGI type from Poujoulat without mastering its consequences on the draft and the functioning of the stove.

[Christophe]

Christophe, can you come back to the departure info? From where ? What brand ?

I do not know it was not specified, it was the advertisement of a multi-brand seller (may be that of the youtube video ??) ... obviously now I can no longer get my hands on it, probably already spent old paper!

It should be found under "google our friend" ...

[bernardd]

Suction cups are prohibited, except special stoves and specific connection.

According to what documents is a suction cup prohibited for a pellet stove?

This is not forbidden, but it seems that it is reserved for "airtight" stoves, to avoid any interaction with a VMC which modifies the air pressures and which would risk reversing the "draft" despite the ventilation.

[Philippe Schutt]

That's right. The stove must be waterproof and must, in association with the smoke evacuation system, have a technical opinion.
These stoves are still quite rare.
I said prohibited because the DTU prohibits it (exit 40cm above the mandatory ridge), and the procedure by technical opinion is an exception to the rule.

[dedeleco]

Given the number of houses and apartments without a fireplace, stoves and small vacuum boilers, with just one hole to install, are the cheapest and attractive heating solution for many people.
So sealing is obvious as a necessity and security, to be sure that noxious fumes are not found inside.

Even with a chimney, a slightly too powerful VMC, or other bad luck, wind, inversion, can be very dangerous.

Logically an outside air intake for combustion and departure of the smoke towards the watertight outside seems important to me with or without chimney.

Otherwise, I don't understand that ignition is not safer with double ignition, separating the functions, the base candle or heater which heats the pellets and generates gases and that of ignition, different, above which ignites the emitted gases, with detection of non-combustion of the gasifier gases (diode detecting the combustion light), to accelerate the excitation of the spark plug. ??
One could even, after ignition, excite the gas spark plug (spark) once per minute, because the energy expended is then negligible, compared to that which heats up upon ignition, and even compared to that of the circulator d air, for total safety, never to have gasifier gas that accumulates a long time, without burning.

I think there would be no risk of explosion then, with a system that remains simple (diode and spark plug in addition).

[roy1361]

One could even, after ignition, excite the gas spark plug (spark) once per minute, because the energy expended is then negligible, compared to that which heats up upon ignition, and even compared to that of the circulator d air, for total safety, never to have gasifier gas that accumulates a long time, without burning.

It's a good idea, dedicated. Simple and probably effective.

Did spoke quite a bit on this thread about the highly unlikely explosion problems for our boilers. I follow what he says, but out of curiosity I reopened my user manual for my P2.

In the warnings, it says 2 things:

1) External influences such as insufficient combustion air or substandard fuel can cause serious combustion failure (e.g. spontaneous ignition of slow distillation gas / deflagration) and subsequently cause serious accidents.

And:

2) Risk of serious injury and property damage if the smoke evacuation system is defective.
The harmful influences of the smoke evacuation system, such as p. ex. fouling of the flue or insufficient draft can lead to a serious combustion fault (e.g. spontaneous ignition of slow distillation / deflagration gas).

And there, we are talking about boilers, and what is more "top ten" ...

Good night...

[Philippe Schutt]

Any combustion appliance, and in particular solid fuel burning appliances, presents a risk when maintenance is not done or the appliance is defective or its installation / start-up poorly done.

[bernardd]

Today, the most advanced pellet boilers are capable of measuring air flow, temperatures and the level of oxygen released in real time: they can accept any type of pellet, including locally produced from previously composted biomass waste, as it adapts combustion parameters in real time.

And they are also protected against any type of explosion, because if the air does not circulate, they detect it.

The necessary sensors are still a bit expensive for the stoves, but the technology will arrive in 2 or 3 years. Targeting efficiencies of 96% at any diet :-)

[Did67]

Did spoke quite a bit on this thread about the highly unlikely explosion problems for our boilers. I follow what he says, but out of curiosity I reopened my user manual for my P2. ...

Well, I thought that the vacuum detector, smoke extraction, forced ventilation, etc ... made it unlikely (impossible?) The situation where the draft is insufficient, the gases not evacuated (even if the laziness extinct ... for ej know what reasons), so the potentially explosive situation ...

Ditto for the ignition phase. On my Okofen, there are cascading controls: opening of the Bélimo valve only if a minimum temperature is reached, then operation in "accelerated" mode without introduction of pellets, then switching to normal mode, with arrival of pellets, modulation of the fans ...

But hey, "I thought ..." ... I'm getting more careful now (although I also drive on LPG despite a few "explosions" reported here and there).

I did not take the time to reread my doc.

And I do not know if dedéléco found, in his research, information on "explosion" of pellet boilers ???

[Philippe Schutt]

Today, the most advanced pellet boilers are capable of measuring air flow, temperatures and the level of oxygen released in real time: they can accept any type of pellet, including locally produced from previously composted biomass waste, as it adapts combustion parameters in real time.

And they are also protected against any type of explosion, because if the air does not circulate, they detect it.

The necessary sensors are still a bit expensive for the stoves, but the technology will arrive in 2 or 3 years. Targeting efficiencies of 96% at any diet :-)

except for the oxygen measurement these sensors are actually already on a lot of stoves, but I know of a case where that did not prevent.

This risk of explosion is very very low, it involves an addition of factors. In the case that I followed there was 1 ° a fault with the stove, 2 ° an incompetent or very negligent installer, 3 ° a timing which caused the stove to fault a little bit before the fire takes, either at the worst time.

As the annual visit is legally compulsory for a boiler, the risk is even less. On the other hand, if stoves arose a bit no matter how 3-4 years ago, this is no longer the case.
However, people have always done anything, I also saw a teacher who had blocked with plastic bags a smoke evacuation of a gas water heater because he found that it made an air intake cold. another who does not clean his stove so that the light of the flame does not prevent him from sleeping, or another who adds blocks of pallet wood or briquettes of old paper in his pellet stove. And all these good people are angry with their device when it no longer works properly, and of course do not admit that it can come from their fantasies.