Page 36 - konishipaper

Ls and slag pool diameter DO are introduced .corresponding to the .exper.iments・ 吐le electrical and thermal propercies・ necessary for .the:calculation areintro- r;ducedβs.i.the， func:~ions ，ofぃ仁己mp号ratu:re(14，.15，16). Among.them，i，the.el.ectrical
conductivity of slag is expressed(16) as;
σs( 仁)子一 3125.. ~xp(~1 1500/τ). ・ (S/m) !(9)
The vo~.tage
仁emperature.distr再bution. When the.elec~ron . emission
:requ子redmqre，than~he ~her~al .~mission ， expr~ssed by
~rop ，
in ， each
r~gion
.could.be decided.by Eq.(3) after'，getting from the'slag surface is
'1 -・2'
'T'
2: ぷ・ .¥'r'7r'"'•2
‘:
工 .二，Jー冗D，.L.
':'.Ua.-:-n. .1.mp a
l?ight
J~5. The val.ue.was de巳 ~ded
are also plotted in the figure.τhe quantit~tive
A T :. . .
.t.he elec~r.o.n~mis~i_on
cathode'drop Vc could be expressed as: ・ ・
"Vc=.V1+V2・+，V3十 V4+Vt
3.2 ，CalculatedResultsandDiscussions
，."， .'
‘，
Fo~lowing
v~lues.'are
adopted in the;.calculation.
v. • w a s
~
2 ， 7 0 0 K ， T = . . 1 ， 0 0 0 K ， d - = . 7 . m m ， • T
ー : 1 . 0 0 0 K a n d L _ = 1 . m :m .
.s∞・プ・， 7"iV-I '1l1W e1c ，p，et as.z，e，ro.because the det，ails.are not known..
，.
，~∞=
.
C' (x) .
vVV
i
，
.1.
1
，
<
，.
"exp (-c:t.j.k
.:' (loL.'，
by th.e tunnel-，.effe己t"W ouldbe.added‘，and，the.total
L.
m，~^1.-' T ・
ぺ ".1i.:
The total cathod宇 drop .as ，the .functi.on of:.，arc:current.is shown'in F:ig.12
;W;i)~~¥a:rF'spq~， diam~\仁er. D
a
by，rough fitting ヒo the.experimental.values，'which agreement、between theoretical valu巳s.are，within 仁he.r，ange，.andthe dimensiqns.'of arc'spots a n d t h e t e n d e n c i e s 田 o f . i n c r e a s i n g t h e c a 仁 h o d e d r o p w i t h d e c r e a s i n g . ot h e a r c
i午urren~(. agτ巳e， qualit.at~yely.
す 毛 ':Che te，Ilperat~r e.d工stributi.ons:工J:.l.f0ur regi0ns;.at.1 、0.2:A，andD ・~. i="4・mm areshowninFig.12. Asmentionedaboye" the_resu.1ts.!3-re.atぴmλ=αー:.="].5.，•and
cu~rent ，
fir~tly
increases and after ~aking
仁he
.
b巳
・
βp~ :.~xP巳r同 en仁al
if the values are increased the temperatures in regions
decrease. The temperature distribu仁ion without current 工s ~lso
figure. Th空 remarkable effect of cuτrent appears.in regエon，l2).and (3)，.while in region lリ _a.nd'W ，the current.diffuses and suppress~s .Joule heating.，even
iι'the'magrI1tlde'ofth~ valuesofαda-d cxs・ . ¥ :
i theleftendofeaphliEe i-nFig.llcorresponds tothecOMitioninwhich the depth'oIarc spot in the;slag layer，Lsa' goes.to.zero..;.A.s‘仁he.increase of
the.cathode drop :
i't:'decreases.，. ThEi.'increase oI arc'spo仁 depth.'.'.'Lsa' 、i).W~ヒh contributesιo.th工s behav工oιThe increas己 of:Ls'a 号orresponds ~o ~he
of' t~e
tota~仁ca仁hoØ~ 'drop:.fal~s:'
t~，i.c.~ness
.v?ltage .:d~<?p:
of';regiqn C!0.， ~n~ . the
‘. :! .f'， T~ei~O~'t'~'g'e，'(i~ó.~s. inth~"，:'regiq~sCD，1叩d1inc目印m6no~oniþallywith
i~creasiJ:.l'gthe 同rrent.、 While.仁h~( drop .in.theregioぱ主).showsthe，inaximumv.~lue by'the'aS'0ve"reas0ri.They01tagedr0pinthisregi0nc0ntributes.t0 the.beha-
:more!~han half of 仁he.total value.
dro.p and oc~upies
.'.'1fth.~.~:i爪~~~e~~~ce b~tween 仁he arcspo仁sis.negl:igible;仁hecatbodedrop'at
vi~r， ι of
下he 、 total
平at~ode
m<?reth~ò." ，Clu.e/arc.，~'an:~b~.eas;~~y .calcula仁ed?1y.thesame.:m~nner. ; The，results.'are shown iu'.Fig. '13"w'ith'rhe e'文}守iperiμ勾hn附
are wit~in
the.correc仁ion range..and the a
653
.Tm~) ー7[ D~ L... mp/4，.U
~s a，paramete.r. .The.expansion.ra.tioscメdand.CベS th~ ，function.of current，but in this cal.culation.they are'.assumed¥as
\.
.maximum，'value the.:Curr'ent decrease in this'.r巳g工on，dec工;eases and
•• • • .• • .
!;'.:
a~d 1 will
shown:..in-，:'the
、J
，
、， il ，‘、