Hobo Stove (epic fail)

[Hammock_man]

Thought I would play with having a fan driven hobo stove ideally to burn then Asda wooden cat litter.

Put together a frame to hold a poundshop cutlery drainer and a fan underneath. Just a small 12volt computer fan running off a 9volt PP9 battery ( did not want it blowing a gale, just steady air flow.

It worked well for a while, very well after that and then very very well!!! Then ..... funny smell but to hot to do anything. Result shown below

That was a fan!!

 

[resnikov]

Thats cool! You live and learn.

 

[swright81076]

I've found the best insulation so far (between fan and heat chamber) is fireproof plasterboard and genuine rock wool.


Sent from my Galaxy Nexus using Tapatalk 2

 

[Andy BB]

Thats cool! You live and learn.

I'm not sure that "cool" is the operative word here.....................

 

[Dannytsg]

Well if you didn't try you wouldn't learn.

 

[Hammock_man]

I would go back to the drawing board but I burnt that as well. "Must try harder" as they say

 

[Shambling Shaman]

I would go back to the drawing board but I burnt that as well.

Funny.

I'm about to try and re-handle a knife for the 1st time so look out for "Knife handle (epic fail)


I have faith that you will succeed.

 

[woodspirits]

top marks for showing us your fail!

perhaps you should treat it as a mini forge with a side fan and a small metal extention pipe into the burn?

steve

 

[Lister]

A thought if i may? Try mounting on the side of the strainer with a box tunnel so the fan can still blow into the fire but is far enough away to stay out the heat...this is where variable voltage control would come in handy.

 

[swright81076]

Tbh a fan works best in a gasifier you may find in a hobo, you'll get more smoke and get through fuel quicker.
When using fans in mine, I have an inch of densely packed rock wool with a piece of foil covered fireproof plasterboard cut to fit. With this your fan wild remain cold.

Sent from my Galaxy Nexus using Tapatalk 2

 

[Hammock_man]

I accept the side mount 100%. This was just to see how the fan would affect the cat liter.
SWright81076 mate ..... understand fireproof plasterboard, foil yes but will the rock wool not just cut the air flow down to almost zero? still glad of the input though.

 

[swright81076]

You're right. There'd be no airflow. I was typing aloud (if there is such a thing), that's my setup in my 'near finished' version.
I've been playing with the idea of using a cheapo travel fan

Stripped down and mounted in a cut down aluminum beer bottle (air forced through neck), this then seated in a hole in the side of the stove. This should increase air pressure into the stove, keeping heat from the fan.
This way the stove could be used with or without forced air.
I know it seems elaborate, but it would work fine with a hobo.
Either that or create a wire mesh grate an inch from base of stove and pray the fan doesn't melt.
In any case its good to have a tinker with these things don't you think.


Sent from my Galaxy Nexus using Tapatalk 2

 

[Teepee]

Just my 2p after playing with these for several years;

Any obstruction to these little fans cuts the flow down a lot. Mounting it on the bottom also does this, mounting it on the side increases the air flow.

I've found a 3" distance from the combustion chamber to be minimum on my gasifiers, a forge burns much hotter at the bottom usually and will need a little more seperation. The most important thing is to never turn the fan off whilst its near the fire for obvious reasons . Incoming air cools it a lot.
The fan heats up mostly through radiant heat from the stove. The amount of heat is inversely proportional to the distance from the heat source, meaning that doubling the distance reduces the heating of the fan by far, far more than half.

The very best insulation I know of for building these is Mica paper or board, you can buy it from http://www.presspahn.com/

Another trick is to glue some foil to the fan and circuit board, it will reflect a lot more heat than black plastic and will make the fan last longer. I also pack the fan bearings with silicon grease to stop ash from wrecking the bearings.

 

[Hammock_man]

Thanks for the input gents.

Think the MkII will just be a free standing fan blowing onto the "fire box" or even just stick with the odd blow from a blow poker!!