[Stoves] Clinker Formation - Oorja and forced air

Mon May 19 02:32:48 CDT 2014

Paul and Michael,

I have also tested WoodGas XL with woodpellets, even before the Oorja and the problems, we faced then.
The ash remain at the bottom of the WG XL, allright, but what about the fines..............?

I have not looked into the different construction of the WG or the Oorja, but know doubt that the Oorja blows the ash and fines into the "room" at full blast.
The cast iron is also an "issue" and can cause serious burns.

That`s why, I am vey doubtfull about the Forced Draft gasifiers and the issue about fines and silica................unless you put a filter of some kind.................then it is getting too complicated.

Otto 

From: mtrevor at ntamar.net
To: stoves at lists.bioenergylists.org
Date: Mon, 19 May 2014 07:41:59 -0700
Subject: Re: [Stoves] Clinker Formation - Oorja and forced air

Here in the Marshalls we had a similar problem when people left the fan 
running on the charcoal in the bottom of the XL woodgas stove too.
The burned out the bottom. Force draft on coals is good 
for blacksmithing bot not stoves.

Michael 
N Trevor

Majuro

From: Paul Anderson 
Sent: Sunday, May 18, 2014 12:15 PM
To: Discussion of biomass cooking 
stoves 
Subject: Re: [Stoves] Clinker Formation - Oorja and forced 
air

All,

I like Tom's comments.    
And I remind Otto and others that there is a major difference between the TLUD 
pyrolysis stage in an Oorja and the carbon-burning stage in the same stove that 
is operated after the Migratory Pyrolytic Front (MPF) has reached the  
bottom.   THAT is why the Oorja has the cast iron cup at the bottom, 
to protect the regular metal from the forge-heats of air blowing on hot 
char.   With the FORCED air onto that hot char, the cup glows red 
hot.   And with the forced air the fine particles can be elevated out 
of the cup and out of the stove, and into the room, as Otto has 
described.   

Otto wrote: 
To avoid clinker formation, we just removed the char 
  [from a TLUD stove] , before it starts glowing, namely biochar.......problem 
  solved?I agree.   But point out that such a solution is 
equally possible if the TLUD has Force Air (FA).

Paul
Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD  
Email:  psanders at ilstu.edu   
Skype: paultlud      Phone: +1-309-452-7072
Website:  www.drtlud.comOn 
5/18/2014 12:08 PM, Tom Miles wrote:

  Otto,

  The 
  TLUD should be the perfect device for high ash fuels. Jock Gill has burned a 
  lot of grass pellets in TLUDS so that should be  good indication. Paul W 
  had burned bundles of grass as you, Otto, probably have. Just as you have 
  described the temperature in the carbon should be well below sintering 
  temperatures low until you reach the char burning stage. At that point you 
  will be oxidizing he carbon at well above 1000C which will melt most ash and 
  you will get clinkers.

  The 
  fine carbon burnout will only be as efficient as the gas burning portion of 
  the TLUD even so it should be very good. I agree with Dean that the carbon 
  burnout in a forced draft stove might be an issue. On the other hand you can 
  have low velocities at the grate and higher velocities above the grate burnout 
  should be very good. The challenge is doing that in stoves that operate at low 
  power, poor air control, and burns with very high excess air. It would be 
  difficult to recirculate flue gas in as small stove. Even then you need lower 
  oxygen in the recirculating gas than you can get in a stove. 

  Tom    

  From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] 
  On Behalf Of Crispin Pemberton-Pigott
Sent: Sunday, May 18, 
  2014 2:48 AM
To: stoves at lists.bioenergylists.org
Subject: 
  Re: [Stoves] Clinker Formation

  Otto that straw 
  pellet test will be important because it may have all its Cl and K in it so 
  the melting temp will be lowered. 

  If processed 
  agri-wastes are to be an important fuel they will have to be accommodated by 
  the designer. 

  Regards 

  Crispin 

  BBM 
  2B567C3

        From: 
        Otto 
        Formo

        Sent: 
        Sunday, May 
        18, 2014 16:39

        To: 
        Stoves 
        Bioenergylist

        Reply To: 
        Discussion 
        of biomass cooking stoves

        Subject: 
        Re: [Stoves] 
        Clinker Formation

  Dean Still,
According to 
  Crispin and to our experience, the flames reaching the cooler pot, instantly 
  create char or black carbon - insufficient combustion create more PM and black 
  carbon........!?

The fan driven Oorja, was tested here with 
  woodpellets, four years ago.
At full blast the "room" was soon covered in a 
  thin layer of soot and ash.
The cast iron combustion "chamber" was glowing 
  instantly- around 1000 - 1100 C.
What about ultra fine particles......?? 

Natural Draft gasifiers, are the way 
  forward................

We will soon test the Peko Pe with staw 
  pellets and see the effects of clinker formation.

Using Corn 
  colbs  (agri-waste) as fuel, we noticed a temperature of 450 - 550 C at 
  the top of the flame and around 350 -400 C at the pyrolysis front.
At the 
  end of the burn, when most gases are utillized and the char starts glowing, we 
  can raech the temperature arond 900 - 1000 C.

To avoid clinker 
  formation, we just removed the char , before it starts glowing, namely 
  biochar.......problem 
solved?

Otto

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