[Gasification] ROCKWOOL

Thu Jan 11 17:58:36 CST 2007

Dear Frans and All:

Thanks for replying to my Rockwool questions.  I found the discussion of 
thermal properties below on the web. 

It is often made from slag (already melted, right composition, should be 
cheap) and was widely available in the US 50 years ago.  My impression 
is that we now use fibreglas instead (peak temperature 500C, relatively 
cheap) or Kaowool (many names) (made from spun al silicate, peak 
temperature 1600 C, VERY expensive) and can't get Rockwool (peak temp 
1000 C) produced in the US.  Rockwool would be adequate for most stove 
and gasifier applications.  Also seems to be good for agricultural 
applications that Kaowool wouldn't fit. PRobably the iron content. 

Any comments on where to get it? 

Yours truly, TOM REED             BEF

Rockwool products provide excellent and long-lasting thermal insulation 
performance. Thermal insulation resists the flow of heat and by reducing 
heat flow saves energy for heating and cooling. Products of our 
manufacturing provide energy conservation and reduction in heat loss 
from installations of high temperature of up to 750°C (the mineral 
fibers can withstand more then 750°C without melting, whereas the 
binding agent start to evaporate at temperature in excess of 450°C). 
These products are mainly used in the process industries, petrochemicals 
& refineries, fertilisers, paper, cement, thermal power stations - 
boilers, turbines, chimneys, receptor of sun-heated boilers, etc.

Rockwool insulation products also play a significant energy-savings role 
in homes, commercial and office buildings, by reducing heat flow (70% - 
80%).  A properly insulated construction uses less energy in winter for 
heating and less in the summer for cooling.

Rockwool insulation products are also provided for areas of low 
temperature. The areas of applications under this would be insulation of 
chilled water lines in hospitals, hotels and commercial buildings, 
air-conditioning and refrigeration ducts, pipes and equipment in 
chemical, dairy, food industries etc.

Following is the thermal conductivity of the rockwool slabs at different 
densities as a function of temperature:

*Mean
Temperature*
*°C*

*40kg/m3*

*60kg/m3*

*80kg/m3*
*
_     W     _
mh oC*

*
_     W     _
mh oC*

*
_     W     _
mh oC*
50

0.042

0.041

0.041
100

0.054

0.048

0.046
150

0.065

0.058

0.055
200

0.085

0.065

0.064

The following graph shows the heat conductivity of our products as a 
function of temperature and the rockwool density.

*Planning Instructions*
The thickness of the insulation that should be used will vary, depending 
on the temperature of the installation to be insulated and the 
requirement from the insulation. Following is auxiliary table for 
selecting insulation thickness based on temperature and requirement from 
the insulation:

*THICK *

*-NESS *

*25 mm *

*50 mm *

*75 mm *

*100 mm *

*125 mm *

*Temp. of the Warm Side*

*(^0 C)*

*Loss of Heat*

*_K-Cal_*_ _

*h * m**^2 *

*Outer Temp.*

*(^0 C)*

*Loss of Heat*

*_K-Cal_*_ _

*h * m**^2 *

*Outer Temp.*

*(^0 C)*

*Loss of Heat*

*_K-Cal_*_ _

*h * m**^2 *

*Outer Temp.*

*(^0 C)*

*Loss of Heat*

*_K-Cal_*_ _

*h * m**^2 *

*Outer Temp.*

*(^0 C)*

*Loss of Heat*

*_K-Cal_*_ _

*h * m**^2 *

*Outer Temp.*

*(^0 C)*

100

96

33

51

32

34

31

26

30

150

173

41

94

38

64

34

48

32

200

266

50

143

46

99

38

74

36

250

372

61

200

49

137

43

104

39

300

495

71

259

55

177

47

158

42

350

390

57

221

52

196

47

400

401

70

274

58

206

50

450

475

73

324

60

246

52

179

46

500

530

78

364

63

276

55

202

50

550

625

85

425

69

322

60

258

54

600

720

94

491

74

373

64

300

58

650

830

100

566

80

428

69

312

62

Frans Peeters wrote:
> Dear TOM,
>  
> Before making place in the PC MEM
>  
> I do not remembering ,an answer to you .
>  
>        Rockwool I use in 600° C accumulation EL heating . Night 
> current cost 2,3 times less than day current.
> 600 Kg Al2O3 bricks takes 7,5 KWh X 8 +2 h / day as standard heating 
> in a room 4x9 mX 2,5high .
>        Wood cassette ,(self constructed / window 40X70 cm ) is 
> secondary heating for burning own wood .from my garden .
>  
>        Burning ,in the drowing IDEA is in the space between 2 grates 
> of differend mesh ! + around the bottom from the returning woodgass .
> I did tests with sums of stainless mesh grates and ash size in my 
> cassete stove .
> Burning wood will produce hot charcoal between the 20-30 mm grates 
> space .  Upper holes 20 mm under 5mm .
>  
> Hoping it is clear now
> Greetings Frans
>  
> -----Oorspronkelijk bericht-----
> *Van:* Thomas Reed [mailto:tombreed at comcast.net]
> *Verzonden:* woensdag 16 augustus 2006
> *Onderwerp:* Re: Best posible GASIFIER WOODSTOVE ? P+S air preheating 
> . Tangenial flow . Speed controls . Lambda sensor in exhoust . Peepscope .
>
> Dear Frans:
>
> The diagram isn't clear, but it looks like you are heating the fuel 
> indirectly through a wall.  This is much more complicated than needed 
> as you will see in our WoodGas stoves.  (Woodgas.com). 
>
> Do you really use Rockwool?  I have been looking for some.   Kaowool 
> withstands 1600 C, Rockwool ~900C, but is much cheaper. 
>
> Yours truly,
>
> TOM REED
>
> Frans Peeters wrote:
>>
>> Dear Stovers ,
>>
>>     Did I forget someting ?
>>
>> 5 termocouples ,displays and regulator are details .
>>
>> Greetings
>>
>> Frans
>>
>>
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