[Stoves] air for gazification

[Boll, Martin Dr.]

Frank, Jeff and all,

Superficial velocity is translated into German as "Filtergeschwindigkeit".
Word by word re-translated to English is: "filter-speed".

And I saw the definition for that in Wikipedia as: (water- or air- ) speed
within the cross-square of the filter-body, without "thinking" of the space
taken by the absorbing filling.

 

I think:

- For filtering that is good e.g.: as speed of water going through the soil,
mentioned by Frank. More difficult it is for describing weather or not an
air-stream through a T-LUD fuel-stack is sufficient or not for making gas
(by considered size and packing of the fuel _and!_ neglecting, that the air
is used!!).

 

- The _real_ speed round the surface of the "filter"-particles is quite
different, as in discussion told. For burning process that is certainly
interesting as well, but very difficult to express, because of so many
differences, as density, measure and shape of the stack.

- And last not least: That would be a _real_ "superficial velocity",  but
the expression is reserved to this "filter-speed", and we have no word for
that, or do you know the definition for that?

-Would that describe better: actual local speed on the particle surface? 

 

My simple question was only:

Within what (senseful) range of air administration do I get a good woodgas
burn. I think in amount per cross-square of the grate(=fuel-chamber). And I
think the Superficial Velocity is more or less the right expression (before
entering the stack!) to describe.

That speed/amount is only _actual_  before the air enters the stack. By
using the air for the burn, this speed (g/second) gets slower.

The amount of woodgas within this stream gets higher. 

The difference to the _"real"_  "filtergeschwindigkeit"= "filterspeed" in
that case is:

The fluid or air is counted, but not the absorbed stuff, and at the end by
filtering there is remaining the entire fluid/ air; but this is not so by
burning-air in a fuel-stack.

 

What _you_ want to know is the actual speed of the air just on the surface
of the wood-particles. This is certainly fine and excellent to know, but I
do not dare to find out such a difficult thing.

 

- Quite another speed is: 

The progradiation of the pyrolysis-front in the fuel-stack.

 Thickness of the fuel-stack (in cm) divided by the burning time (in
minutes); a number, interesting for dimension and burning time of e certain
T-LUD; and from that, to calculate the dimensions for another T-LUD with
shorter/longer burning time. (name??)

 

Best regards

 

Martin