Batch box rocket stove vs commercial wood gasification boilers?

Hallo,


This is probably a stupid question, but what's the difference between a batch box rocket stove and one of those commercial wood gasification boilers? Those have like two chambers, one primary burn chamber where the wood is loaded, and a second chamber below the primary burn chamber where the wood gas/smoke is burnt... The hot gasses pass trough a water jacket creating a central heating possibility.

I'm very interested in the similarity of burn principle in both units. Or is there a difference in operation?

Regards,

Ivo

Yes, actually there's a quite large difference. The gasifier need to warm up for a considerable stretch of time before the fan is turned on and the gasification process starts. Before gasification takes place, the burn isn't particularly clean, rather the contrary.

The batch box on the other hand starts to burn clean typically within 5 minutes from lighting the kindling, even in a cold combustion system. And it doesn't sport a fan, all is done by means of natural draft.

The gasifier need to be operated as a downdraft system, the batch box is a sideways burner like the J-shaped Evans' model.

Thanks Peter for the response and clarification! I'm in the process of building a batch box core after succesfuly building a j-tube one. I'm very interested in the performance of it and I'll certainly post some video's of it burning on my youtube channel "Rocket Stove Experiments".

The reason I asked is I can't stop thinking why commercial boiiler manufacturers don't incorporate the rocket stove burner cores in their appliances...

After tinkering a lot with a j-tube, I'm turning my attention to the batch box core, as I think it is a far more practical thing. The j-tube works fine, but needs constant tinkering, so I'm gonna build a batch box following your dimensions and I'll have a look on how it performs...

I'l keep you posted

Regards,

Ivo S.

(PS: although I know you and me speak the same language (dutch), I want to keep all conversation here in English, as this is a very international forum off course)

A note about the riser of the batch box: don't make the assumption it would be best to make a square riser the same cross section area as a round one. In fact, one side of the square should be the same dimension as the diameter of the round equivalent. The right angle corners are no good at all, in fact those are friction points. In order to compensate for that it should be wider up to the point that the whole circle fits inside the square.
Hope this is clear.