Determination of the Properties of Mineral Wool

(1)

Publisher’s version / Version de l'éditeur:

Technical Translation (National Research Council of Canada), 1953

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Determination of the Properties of Mineral Wool

Erdman-Jesnitzer, F.; Lorenz, W.

https://publications-cnrc.canada.ca/fra/droits

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NATIONAL RESEARCH C O U N C I L OF CANADA

Technical T r a n s l a t i o n TT-412

T i t l e : Determination of t h e p r o p e r t i e s of mineral wool, ( ~ e s t l m n u n g d e r PTaterialeigenschaften von

S e h l a c k e n ~ ~ o l l e . )

By: P r o f e s s o r D r . F, Erdmnn-Jesnitxer and

W.

Lorenz, Frefberg, Sa.

Reference:

Die

Technik

6

( 1 ) ; 13-14, 1951. T r a n s l a t e d by:

H.A,G,

Nathan.

(3)

,

.

l.. 33j.,:3F-7,; ,? c.f raiaara:! i ~ o o l a r c clisccssed md ac G ;:z.,dl;::s f o r n ~ ~ s s : : = . i c ~ t l ; ~ : +,ileri..al c c ~ d u c t i v i t y

. -

13 ,i A J , - 3 3 , - >r:~h+:?.*

.

I?-.

. C, pas",f;71~ y z a s r l i r z r a l : ~ o o l , v~liicli i s oiltair,ed as a

:i- ~. -- A :.xoZ~:c?, I r . o r e ra:luc-:5oc, ::as 71s con2 incr.3 ,rsic;;.l;. I:g:ort *.l; as a l?.es.t"-

d-=r~7310:

-34.

T1;s :itijr?,%l~re cor,';alcs y.7 r:. f ev d a t a or, t e c l x i c d t.ts$ir,g

:.is.':!;~:l; fc.: 5li3 ;:::ysical j.,rop"r-i;i;~s o f ~:!ineriil 7;1ool (1)". Thg2refora,

it

2- ;

-zrs

~ : x - . s s a r : ~ t o ,ive I ~ r i e f l y sone d e t a i l s of v a r i o u s net1:ods of : 3~;~i~-er1er,t ~r:,ici! irere ad21 Led t o a c t u a l cor,ditLor,s acri t 3 s t e d at Cvl~e

L . a t i y ui; f!\r I:e 5all;ii.r:3e ul:d Llaterialj;rdfur:g d e r Rergdcadernia F r a i h e r g ( ~ s ) .

TLe r.,sst I r r i ~ o r t a c t : rci e r t i e s of m i n e r a l wool are:

i.. App,3

a;-z.i;;:ze, c d c u r

7, la:^;'<.^, ~f f i t ! r e

2.

Tl-lc::ci.ss of fil.lre

L

,

Pi-opt,. --:.inn c f r,zr;-.f i h r o u s ccr.ly:ocer,ts

(4)

- 2 "

L?.

S y u c i f i c ~ r a v i t y

9.

3eiLavicnr a t !,4,11 tsrill,era.tures ( p i r , t s of e n b r i t t l e r s u c t ,

sir:t.:xi~: mil s o f t e ~ i c ~ ) 1.3. T!:ari,r;il ccr:ducti~5t;r

Fo=. sl:..:ciul I!?:;r1:r;sas kr,onledi;e o f t h j f o l l o n i c g prop.:r"-iss ng7

d,3is

he c;ji3f111:

11. E l a e t , i c i t y , l ? r i t t l e r , e s s o f f i b r e s 1.2. So~:i:d a d s o r p t i o r ,

Tl:i,s ::ejejp2r d e a l s or,ldp :;.lith .:he m~:asaremact CI:'.' $ 1 ~ 2 pro1 er-5i3s 12s->ed

r 1 G 1 . S_; " c i a 1 i~:ij.:or-k~ar,ce i s a.tCached 30 t h ? r x a s u r e n e ~ t o;_" ti i e r x e l

cor_d~cti-rit~;. r:!~icl: s n c c u c t e r s mcrs d i f f i c u l t i s s "Uhac t h a t or" tire o t i i s r : . r o ~ . ~ r t i e s . D e t s ~ ~ : l i r : a t i o r , o f p r o p e r t . i e s 1 t o 9 2s c o r r ~ p a r a t i v s k i e a s y a d 2 fa-;; b ~ i e f n o t e s s t o u l e s u f f i c e here.

1. Ar:l..sariu:ce, b c o l o ~ r

l b : s r d y c o l c t ~ . r , h c z i o ~ e n e i t y , obviouscess of t h e s l a t p?'

e.

,

-t];.: v i ~ i l . , l . e c:12rYet;3ristics

,

!

s9:culeL :)e L ~ v B ~ : . 3. L~i:;th of . P i ' > ~ e

Ir,

~er,i.r.c~i i-; sl,ould s;:ffice 30 d..t:ern9r,a 'ciio n o o t f r e r p e r i t

p

,-: ,-.:r - ., ., l:?r::,t.ks sF!:l~,i.~~- h:r p i d l i n ~ OI,~"; f i : l r e s frcm 1 3 i ~ e ~ d T ! C G ~ ~ : l i k h t7,yeezzrs

- .- 1 ; rnl *1-3 f 5'1~3;3 31-3 -bliul; -,..laced a ,;Jc*ss :-.ll;te w A d r;,,jascr2d.

Ar; ._xoc-':. P e l ; e ~ ~ : l . 1 : ~ , t i c ~ o f >);e d j - s - t r j . ' u t < o ~ of T i b r a lk;l:,.$J; i s i;c--. - L ~ c ~ f L . l OX&?

''

l..;i't of -::LC ?:as+, i~istor:r ol' t L e : s l r i u . r a l 1 ~ 0 0 1 (e. j. si!i~!pir:e ar,d

-.

-

r u - ~ t o i - i r : ~ ) 13 k:.11o-,yjr~. O~:rir:g t o -(;he 1 1 r i L t l s n e s s o f tiie f l l ) r z s %lie i : r o ~ . o r t i o c o-? l o i l l C ~ ! T L I S d l - c ~ e r . s . 3 ~ t l . 3 nlorv f r e ~ y ~ e f i t l : ? aEd xilore v i g o r o u s l y tl,2 n i ~ l s r d

- .

(5)

3.

?".IS.c:rrAass cf f i b r e

Tiis t::.icknsss of t h e f i h r c s i s ri1easured ur:dcr a microscope

! .,;. :: J . ? . ,ilar r e f l s c t a d o r t r a : s n i t t e d li;h4; a t approximately 1:150-3CC

nagr,i.ficatton. T h i s c s n be ilone sir;q,ly :I:- ~ . u t t i r : , , ; t h e f i h i - e s orl a: o 1 > j e c t

r,iicrometar r.'l:ic:; 1 : ~ s 772(31: n e t t e d =;%!I a l i i l u l d . AS t!;e rvettic, li,:-,uid

5; sc'sat,ar:ce ~-<;ost. 1.efTackii:lt? i n d e x r, i s s i n i l a t o tila': of 'Jle fj.bres*

s;lould 1;s s.zlixta:; .:Lr,ct? i f c d-iffei-s g r e a t i y , t l i i s \ r i l l r e s u l t i n ,;rza';er o r s n a l l z r e r r o r s o f riieasurelaant d.1y.3 t8c r e f l e c t i o n of li,liL,

Q l o l ( n = 1.50) o r T e t r a l i r , (r.

=

1.55), f o r example, should s a t i s f y t h e op?ic rs;~.;.irer:;er:.:s.

or

f u r t h e r d a t a s e e r e f s r e ~ c e

(3)

.)

Rc,rzdlc;;: iJ:a u s a f u l c e s s o f a c c u r a t e l y d e t e r n i n i c ; t h e

d i s 5 r i 3 u t i o r . o f f i ' l r e t1iic:cnass $lie s t a t e i !er,t under 2 a l s o a p p l i e s here. Sicce :he l o n ~ f i h r e s &re a t t h e sand t i m e r e l a t i v e k r +:lick t h e

i,ro:?or",oor

cf

t l l i c k s r f 2111-es i c c r u a s e s 1:~ilen t h e f i b r e s break.

4.

Prcjportioc o f 1:on-fibrous compocacts

I n orrler t o determ!.x:a t h e i , r o p o r t i o n (by r.:ciLht) o f nor,- f i ' r o u s cor:;i.oner-ts o f

mi;-,-

, o r a l ;a001 t h o s l a g p e a r l s n u s t bct ssi;zlrated :rcm a :.:sighed c:;:~u=tit~y o f m i n e r a l nool.

5.

Behaviour ,:{it5 r2s1,ect t o n o i s t u r e

The m o i s t u r e c o n t e n t i s o 4 t a i n e d hy deternir5r.i; tile cl;ix~z

ic :,el$t a f h r storir;, tlia rnirisral no01 i c atr:losj;haras s h t u r a t e d n i t i : r::.,-L\+r vaL.c.r. T l i ~ ti:.;e o f s t o r a g e afid t h e Cverq:-3raL;v.rt. m1lst 52 r$corded,

o r c c u r s e . I n adi;itlol:,

it

::'auld h e veln.-y z s e f u l t o detarmir,.2 .ti:.. c!~=ll;e i c -,<il..

-

,LJi & t a r dryin; a t 1 5 0 - 2 5 0 ~ ~ . arAd t h o t i n a

it

t a k e s t o c i l a i ~ e

.*. 7.

;L,.: ;,I$T:_:?.': r~:izr, a sar:~-,la o f r n i ~ e r a l wool i s s t o r s d i r , a r,or;;:sl atmospliere

*?::e r e f r a c t i v e ?.ridex cl" g l a s s o r slaz 1::a.y h e c a l c u l a t e d ;i.l:.r~xir!;.!;ely fro;? -tl.i;il, c ! ; s r ~ i c ~ . l corn:.ositioor ( c f . r e f . 2)

.

(6)

- 4 -

a f t e r 1:,ro.~Ao-;-s 7;a:tf c . s - d d r - . , , ' ~ . ,

V I - . - , , From tlie

l e t t s r

t e s t it caR be

d...~ L , , ~ ~ = .A,l..dd .72 r:rl:s::;a:- cx.d l.,o;: ra::icik-

the

r , o ~ ~ a a l s . t ~ t c ; ,f miners1 r;.ool i s r3-2s",?~lisl;c:d d . L e r ahsorl.:tioz cc;f ~:n:er (sdsor;.;tioc, a b s o r p t i o c or

rscil: i:: a"vlo2: o f micube coc;iacsed dro;,lets) a d d r y i r . ~ .

6.

1)II value

The

::,icaral v~ool is Ic 8. giver, aruouct o f n a t e r (i.e. t a r , t i m s tile aoul=.t o? t h e mineral ivool,) aEd a f t e r a gi-gec time

( s a g . 10 nic~:tes) tile pH value i s determicad. This metrsurernect n q ? he made electrorrletrically, 11u.Z t h e use of i c d i c a t o r 2aper should he

suf f i c i e c t . Ic g . j c e r d , es1:ecially vilie~ th e r e a c t i o n

i s

n e a r l y cs.;tral,

i t is: recomnel:iiad . t o f ~ c i l t1.1e sample f o r a sllort time. This :vould d i s p l a c a tlis pIi value from n e u t r a l towards a l k a l i c e o r sour r e a c t i o n , depecdir,;. or, the c:lor.lical stx.u.c%ure of t h e n i m r a l ~ ~ o o l .

Ir. a:?

case $1:

.

;.?I value s l ~ ~ u l d be nisasurad a t room temperature, otherwise,

c o ~ i i p ~ i ~ o c , ; v:ould be d i f f i c ~ l t .

7. ' Y s l ~ h t 1.i.r ~ r c i t v o l u ~ a

Tlie ;-jei,l;t p e r ucitl voluxl;e ( p r e f a r a h l y Z c p s r cu. n.)

1oq.r bs2 dstermiced from the mass mcl

the

v o l m e occupizd by t h e ~~~~~al

..700l, 2.~. sir;?i..ly !I>- aeichir:i; i c a vide r a e s s ~ r i c i ; cylicder. T l ~ e s t a t s

of co:~;ressioc ir. each case must be ,;ivel: (e.2. "s1ig;ltly prsssed by hzcdrf, o r "Sevoraly I : T ~ S S O ~ " , etc.)

.

Deper:dicg o e the use ictectied, it may he cocessary, uxder c e r t a i n cor.ditiocs, t o dotenniced t h e 7:rei~l;':

!yr voltu;s of

t h ~ ?

sary;le i c tha r ~ e c h a ~ i c a l l y conpressed s t a t e md give

(7)

C. Si..-.c!-fic " r a v i t j

rn Lf;e easit:: s t v - ! ~ ; - of d.jterrir:il: J the s1,eci-f i c ~ r ~ ~ j f t ; r (

.--

, ~ I - * . / ' c c

.)

cf -tl1;

sl:..

.A, . sl,;'-,s-:;,rpce i-Lselr

is

s , - 0 . i . l d L i ~ g thrj ~ C ~ S U T S L ? B ~ . ~ S OR ~ 0 x j : a c t

1 . If or:l:r r.lir.3rd vrool i s a v a i l a b l e , t h e f o l l o m i c ~ method vor:ld be

%!?a s i ~ ~ z l d s t om:

A 500-cc. ~~zasui-ici-: cylixder i s f i l l e d r l i t h water t o e x a c t l y

400 cc. s:d es ;.~ucli nic.;ral ::ool as 1:ossihle i s ~ u t i c t c i-5. !Ic:iaver 9

c a r e must 1~ td:sr, t h a t

m

d.r huhbles form oc thu raiceral wcol (tlia r.:ir:erel 7::ool ri;v.st !,a zdded i n s u f f i c L a c t l y m a l l p o r t i o c s ) . By rei;;hir.; t1.o diff.;1*c:nc:-?s EC?~?, %;I d a t ~ n . i i ~ ! . n , ; t h e arfiount of l i r p i d displaced t h e

s2::xific ,ravit;,r !nay hs o l ~ t a i c e d with

m.

_{accuracy o f}_a_{few per cect.}

?:,z vn!.rl.: kj of tlie s l a g s ~ l h s t a n c e

ic

t h e micaral no01 rnzy ha

c a l c u l a t e d

i c

p a r c o ~ t c i i r e c t l y from the weight by volume ar.d t h e s p e c i f i c

zr

avitg.

9.

Behaviour a t hidti temparatures

The n i m r a l wool i s heated t o t h e elt tic,: p o i c t o r 1:oir.t o f ;;.lsssy fusior. ( a t 1 ~ 0 0 - 1 5 0 0 ~ ~ .

,

d e ~ j e ~ d i r . g or. tlie clienical c c n ~ o s i t i o r . )

.

Tho sictsric;; ter.q s r a l u r e

i s

c i ~ a r a c i e r i a e d by t h e agglomera+uion of t h a

iricural :.i.,ol t o 3. 115rc1, h r i - t t l o , hut s t i l l f i b r o u s lump. I f t h e tern~:lt.ret~~re

i s i c c r e a s e d f u r t h e r , t!;e llluss f u s e s t o a touch p a s t e which ?iecos:'.es

c a s a T h e t e ~ p e r ~ - ' ; u r a be measured v i t h e. p y lseter

,

o r , i f ~ r s a t accw'aclr i s c o t r e q ~ ~ i r e d , sim1:,ly by ol)servir,,: tiie tenpar colour. !Sir.cz -L:.c: s i c t e r i x t ; a:d melticg processes extsr.2 ovzr ar, e c t i r e temper- a h r e rar.ze (esch process a~-.prcjxinately 50-150°c.) t h e t s r n s lasfnteri~:;; I C ~ ~ T W I ~ 1' zed Itnsltic; i n t e r v a l " r~ould l3e ;;;ore zppropriate.

(8)

dies Licit;. --I:< t i L 2 <i it tier-ex': a f t e r 1 . ~ ~ i i i ~ l g t o tenper a t u r e s d i r e c t l y I~alc,! ",1;.. s i c t e r i c ~ i c t s r v a l ar.d s u h s e q u e ~ t coo1ir.g and t o attempt t h e datermixation of ar, llernbrittlemer,t temperature".

10. Thannal c o c d u c t i v i t y

Of t h e mmerous e q ~ e r i m c n t a l setups f o r determining tlle tilsrrml cor.ductivi-t;r t h e f ollorvic;: absolute method i s b a s t s u i t e d t o t h e 1 1.03lei.i 0," riaasuricg th,: thermal cocductivit:: of f ihrous subst a c e s

( 4 )

:

b sl.,llurical, a l a c t r l c a l l y heated n e t a l body i s enclosed hy 3 : o o so t h a t p r a c - t i c a l l y t h e t o t a l h e a t produced ir. tha hody r x s t ;,dr:atrat3 31s :-~dtax~ial 1;o 110 rfieasursd as a h e a t flow. The mlceral

;loo1 in

Lurr.

i s ttl:closud by a sp!lerical s h e e t n e t a l casing. The e n t i r e satup tkus i s c o n ; ~ l e t s l y s p h e r o s ~ m e t r i c . I f , e f t e r a t t a i c i c g a steady iiaa; flow,

t h

t,~rLii!arat.~re T ₁on t h s s u r f a c e of t h e ilsaticg sphere ( r a d i u s r1 i n cra.) acd tliz temparatui-e T2 on t h a o u t e r sphere ( r a d i u s r

2

ir, cm.) a s me11 a s

t!.?

ilast e f f i c i e c c y of t h e heating bodj,

Q

( c a l .

-1

set. ), a r s r.ieaswsd, tiler. t h a t i l ~ r m a l conductivity i s o l l t a i ~ e d 3s I?oll0:1s:

= Q / - / ~ /

4 x

( T ~ - T ~ ) ₍₁₁ ( c a l . cm. ulsec.-ldegrees-l).

Q i s obtaFcod f r o n t h 3 currerlt inter:sity

I

( i r . amp.) a d the p o t e n t i a l

d i f f 2 r e c c ~ : at, 5:;: f i l a r l e n t 1:1icdicg

U

( i r . v.), o r a t i t s r e s i s t a r x e R (ir, o h ) , Pron t!l~ r e l a t i o n

2 -1

(9)

11: t:;o j , r $ s e c t c a s e i L is customary t o %!~rass "vl? t j l t r r l l a l

,- ,

c o c d u c t l l , ~ l t g ic t h e :x;ic,t.jric;: system of me asura..ior,-i; (di~ner,sioi: kcal.m 7.r. -1

="dsgrass

)

%,raford,

t h

v a l u e o b t d r , e d L-j. ~ r ~ u a t i o r . 1 :lust 112 ~ ~ u l t i j i l i o d

!?y 360.

Tlius

h

₌

_6.35

_{~ ~ ~ ( l / r ~ - l / r ~ ) / ( ~ ~ - ~ ~ )}

₍₃₎

-

-1

(kcal.m. 'hr.-ldegrees )

,

wlisre r, T,

I,

mad

R

a i : e x p r e s s e d i r , cn., d e g r e e s , mp. a d ohm,

r e s p c t i v s l p ,

Fig. 1 shows ';!lc neasurir,g e q u i p n z c t based or, t h e p r i c c i r ; l e d e s c r i b a d above. T;ia s h a a t : n e t d s p h e r e ( c o c s i s t i ~ ~ o f tvio hemisp!lares of alurninw.1 s h e e t , a j , ~ r o x i n a t e l y 1 m. t h i c k ) e1:closicg t h e h a a t i c g body =d t h a :niu:eral wool i s sLo;:lr, 01: t h o l e f t . FVircs from t h e s i d e s o f t h e

t,-:lo h a l f s i l c l l s l e a d t o f o u r < h a r m o c o u ~ l a olomects =d l l s a t i r , ~ f i l ~ ~ ; i z r , . t .

X Denar v e s s a l c c c t a i c i ~ g 1:atcr sl; 8i;proximately 20°C. f o r k o e p i c g t h e -Zarnl;3ratur3 of ?,he s o l d e r e d j o i ~ t s 02 t l thurmocupla e1rrner.t~ cocutact. ~ i s slionr,

ir,

$112 c a n t r e c:' Fig. i. Tha ~;alvar,omneter f o r rnoas7.1ricg t h e

ti - - . , - c r : .d m- i c s t r u m e n t f o r c o c t r o l l i r , g t h a f i l a iar,t c t i r r e c t a-3 s::o:.ir, or, 7213 r i g l i t . Fig. 2 s h o w ';he a r r a i j e i n d ~ t o f t h e p o i c t s a t which t l x 't2cl;:arature i s rzeasured (i.e., s o l d e r e d j o i c t s of t h e tnermo- c o u ~ ) l e e l e n e c t s ) mad tile w i r i c g o f t l ~ o tliermocouple e l e m e ~ t s . Ir, o r d e r t o avoid e x c e s s i v e e r r o r s o f measurernect

( 5 )

a t e r , ~ p e r a t u r e drop

ir,

t h e 'Jliar;.;ocoupls w i r e s i r , tllu immediate v i c i f i i t j r of t h e s o l d e r e d j o i f i t s r.iust

$2 p r e v c c t e d ; otllerwise, t h e s o l d e r e d j o i n t s ni;ht he coolad t o a te1::;jar-

a t u r e halow t h e t r u a t3mperatura a t t h e measuricg poirit hec;.use

s

f

h = a t c o c d u e t i o c i c m e t a l s v n i c h are good c o c d u c t o r s compared v i t h t h e ~ ? i c s r a l

(10)

- 6 -

:-.~ool. T ; i l s i s ::i-ovsl:-b~d 7~;- ".lo ~iliril:~; s:107711 Ir. Fi,. 2.

"7.

:..G b a s i c c i r c u i k d i ~ r a ~ o f a -L::srnocou;ile olu:,lcr,",is s:io.,n= i F

3.

For tlie ; , ~ o s ~ . t i;uZi'jiosa coj:li,.3r iy.2 C O C ~ ~ ~ . t i ~ 1 = i;:.arilcrco~iple

dlensr..l;s ( t ; ~ < 3 r ; i o c ~ : . ? ! ~ : : * i c f o r c e q~proxirnatoly

0.043 mv,

]!or dcgroa o f

d i f f a ~ . : c o i r , te1~;>.3rat1.1ru bat~voec tv ~ o soldered j o i c t s ) a r e s~iiLt:i?da. A

s u f f i c l ~ ~ l . t l y s a c s i t i v u galva:on3tor n~jasurkts t h a t!i,3rrLloalucl;ric c1.1rri31:ts.

T ! I ~

tl:..$rnocou~ple e l a r n e ~ t s a r e cali71rated si:rply

by

c o r . ~ . ~ ~ r i s o ~ : :.:itli a

ci.J.i'.~rat~d 5:~~~rnozncj';er.

Th.3 di1:13csiocs of t h e Ilaatir: j bociy ca: '>#:3 u 3:>i: 21: I"' -,,,&

.

d . + .

'

T l ~ s filanier,t ~ r i c d i r , ~ s (l!ichrone ire, a2,proxiraataly 1 C O olx.~, load xi: t o ai*i.roximai;ely 330 r~ia.

,

corras;~or.dir,g t o a caidacity of ~ ~ ~ . , l ? r o - r i ~ , . ) , ~ - . L I ! L ~ U e l y 10 ~ r . )

car, e a s i l y 173 placed i c s i d e tho h e a t i n g body ar.d jl:'3i?;1-+n A J s l y a i h c i i e d

t o t h e screw ~vhich lo c k s t h e hollovv sps\ce before ti,;ht;aci~.:..; t:,a scrwv. T i t l ~ -the above d a t a

i t

s;lould riot ha Z i f f L c ~ l " ; -Lo ,?.ssy . - u I: ari

a;:paratus f c r ~ i e a s ~ u r i c ~ t l . 1 ~ tlieri.~al c o ~ d u c t i v l t ; ~ 01" l i ; i ~ e r a l vro01 i t s e l f . Tli;: f o l l o . : ~ i c ; co-tes shoulci f a c i l i t a t 3 t h a maasni:.~r.ii.!~:t.

,

.

Bsf o r e t i i ~ m e asu:*zn..dr,t l ~ a i i r , s tl:a lolrar

;;:,

,".1 ....' (;Lo :.LC>. :3. sj ,.,.3r2

i s u ~ i f o n d ; ? f i l l e d w i t h rainaral woo1 a d .the lleatini; '>cd:r

i s

2.11aced

i n

t h e cdl:tl*3 (as n2 auured hy tl:o o;d)

,

Then blie uI?]..;.r s h a l l o f t:le l.iumisp:i3ra i s ; .u-:: o c =.ti -3rou;:i i t s ; a:

,;.,3r

oi:,anir,; tlls rema;irAn,.. c 3 i"Llli:d

( c f . F i l s . 1 a116 2 ) . Tlia b:-.';l,?g-current i n t o c s i t y i a so adj~.~:;ted 112 .A;o s e r i s s r e s?'.si; &me 5;: a t !,u-L~~ool: thi-: i lx o r md ouLor me a s : ~ r i n c l.;oir,'ta :.I

dif'f.=rd1:~4 3.1: .t~i.li:dl?gfulll'a ( ~ O - ~ O ~ C . ) , rvhich ba m4:?usur'ed

i c

'blia ~ a l - ~ , ~ r s , o r ~ ~ ~ l ; e r vri-th s u f f i c i u c t accuracy, r e s u 1 . t ~ .

Ic

orcldr t o has tar: tlia

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i t i s practicahlt: t o oiiarato nit11 i ~ c r e a s e d c u r r e c t i c t z n s i t j .

f

rorn the

. .

l e , l ~ n i ~ g . b ! ~ v e r t l ~ s l e s s i-; 1411 -take from 1-3 liours t o e s t a b l i s h t h e sc;uilibriur.~ a:d tlis t o t a l time required f o r a meast:r~r.nct should be from 2-4 hours. IIo~~ever, tho apparatus ceed cot be watched cocticuously.

The thomild cocductivity i c c r o a s e s as tlie closecess of pac:;icg o f tlie micsral wool iccreases. Tllerefore, tlie weight (by volur;~e) of t h e m i ~ c r a l wool ir,

t ! ~

r3;1karetus n u s t alrvays be recorded. Furthermore, s i c c e i;lld t;lerz!al co;:ductivity of miceral \roo1 g s c e r a l l y i s c r e a s e s with t e m p r a t u r e -tl:e meac naasuricd teraperature slloulci a l s o 5e given. Since t h s miccral

r-roo1 i s cs ve r completely homogeneous

in

a me a s u r i c g apparatus a d hec ause of o t h e r e q , a r i r n ~ c t a l e r r o r s ( a . ~ . s t i a l l i r r e g ~ l a r i t i e s of the h e a t i c g c u r r u c t , heat cocductioc o f t h e wires of t h e thermocouple f i l a m e n t wicdic,, atc.) sr, accuracy from 6-10 per cent n u s t be cocsidered s a t i s - factory.

3iblio;:r a1311y

-

1. Echiebol. 2 ,

l3.

Fischer

TJ.

a d 1701f, S.

"Schlacken~volle aus Iiochofenschlacke als Austauschwerkstoff

lm

f ~ r Asbesttt ( ~ i n a r a l wool from blast-furnace s l a g a s a

s u i ~ s t i ' c u t e m a t e r i a l f o r asbestos) sumnary r e p o r t 1947 (uq~ublished). 2. DIAcs-Lax. TR ,zl-.ecbuch f u r Physiker uEd Chemiksr. Ekrlic 1943, p. 1358.

3.

DIAr,s-Lax. loc. c i t .

St,auds, H. Physika1.-cliera. T a s c l ~ e ~ b u c h . Vol. 2, Leipzig,

1945.

4.

Koidrauscl~. Praktische Plijrsik vol. 1, 1 9 t h e d i t i o c , Leipsi; 19L.4, 11. 270.

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F i g . 1. Experimental setup f o r determining t h e thermal c o n d u c t i v i t y o f mineral wool.

F i g . 2. Cross-section o f t h e s p h e r i c a l measuring instrument, showing p o s i t i o n o f t h e p o i n t s a t which t h e temperature i s

measured and t h e wiring o f t h e thermocouple elements.

MI

...

M rn p o i n t s o f measurement.

4

(13)

F i g .

3.

C i r c u i t diagram of a thermocouple element.

a

-

copper; b

-

Constantan; c

-

point o f measurement; d

-

soldered j o i n t .

Fig. 4. Cross-section o f the heating body. a

-

space f o r filament winding; b

-

copper.