Page 32 - konishipaper

i n g o t o f u n i f o r m 1 y ' m i x e d s o l i d s o l u t i o r i '， a n d c u t : i n 4 m m t h i c k a n d 2 0 m m ，i n
The"slag was seヒ ・on the meta1 (SUS，304)'e1ec仁rode'of'，the diameter of 1，7 mm and the ヒhickness'of"10 mm surrounded by doub1e C:eramics;tubes (insid己 Mg?" qu仁side: A1i03);:'The inner magnesia t山 e was'set'in the. gap beヒweenthe"e1ec.trode"periphery"andtheinne'r:s'urfaceof'.a1umina'ヒube. '，The
d-iam~ter. '
pooled:s1ag'was:29 min and the・ヒhickness 4 mm. The白 e1ec仁rode was
diameter o~
st，icked ouヒ"from the' ~a11
me1ted'.' ，The e1ectrode temperature '.ras'adjus'ted :by inserting .kabwoo・1 'pads between 仁he meta1 e1ectrode and a'waヒer j'acket.;.The;'，observ.ation window"'was 甲0卯 ted on the upper wa11'and ヒhrough wh土ch TV " Øictur~ 'was 'taken ~ and'recorded
t y : V T R s y s t e m . T h e w 工 n d o w w a s s u r r o u n d 'e d b y 'a c o a ' x 工 a 1 m e t a 1 'r .i 月 e l e c t r o d e lis'ed"a'stheop'o'site'e1ectrode.'， 、 1(， ・ 2 、:"r:， ;''1'.':
， The ipp1i~~
The image'taken byTV camera system and the'signal-s recorded were，synchronized. Th'e"el、ect:'rode't旨mperiturewas'measured~y ι:sheathedK-thermocout1e'of'3.'mm'in d i a m e 't'e r . ‘ A n 'i r i d i u m 'r o d o f ‘ 1 m m x ' l m m c r o s s s e c t i o n w a s ' i n s e r t e d .i n t o t h e p1asma f10w to me.asure the ，p1asma potential. In， this studi'，'the"pot'entia1
arc:spots just afte~ ， the
arc discharge start unti1.the end of ，
experi~e~t
TV :pictur~ fshows
・
slag:- -The pfotted points consist of the
旨 urf・ac，e'by 5'mm:in 0rd'er to'keep'the p001ed;S1ag
the current weie recordedby a1PCM'recording system.
~o~tage ，' and
differences'between thep1asmaand仁 he'e.1ectrodepotentia1s' we~e e1ectrode drops.τhe error wou1d be within a coup1e of Vo1ts.
ι・l ' ，，
2.2 ExperimentalResu1ヒsand.Discussions 2.2.'1'，'Electrode， 'Drops'.' ・ (1)，:'Cathode Drop ¥ ・
Fig.2:shows the'cathod'e'drops ofvarious:kinds of slags， as.afunc.tion of
current. Although the:e1ectrode temperature、is not 仁he same for each case，the'slagscontainingFe203andK203showsapparently.・1ower.. cathod~， drops
a~c
仁han that of the original
by' t~e
iwhere"the.poL:.lrization'becomes'stab1e. No， apparent time 、dependen~ .v~riation of
cathode drop cou1d not be .observed from the'figure.. ，The，'.main， r，eason : ，cou，~d .(þe considered as the potassium content in slag was not varied since ヒhe seed leve1 of potassium in the gas was low and 1ess seed materia1 cou1d.，n，ot get"in it and
AnodeDrop
"，'The"typica1:timeidependent，signals of anode;:drops for the slags.o:f.f~y. ash
o'n1.y'an'd of 5 % Fez:03、added are shown in Fig.3， (a)・and (b) respective1y.. The amp1itude of.f1uc仁uation of anode drop for (a) 100ks 1arger than that for (b).
the¥':violen'tiibubble，formation'occurs，for，:(a)"，but.ca1m"forma- :tion;.for;(b).'，、:Th:is ，bubble，could be 'considered，as'oxygen'produced:by，the
elecriochemical，reaction.inlthe， slag near ~， the
in 仁he s1ag did not change since，:it;:.tad‘，b'een 'established after!the start'of discharge.
the po1arization of potassi~m
• •.
、 ~i~(2-)"
From ~he .
of e1ectrode"surface'afte，r'.the・experiment，no c1earιdifference，:was.observe.d.for
・=(a)，"f:while many'pinho1esiof.:diameter of about O.S'mm.wer己 found、out， for (b). .!The electrochemica1"reaction'，between iron I.and/or chromium in'the:e1ectrode..and '，:anion.of，0ーで。in the slag.suppressed the formation of，oxygen bubble'and the~ore
stab1e discharge cou1d be attained than'for (a)・'
'2:2.2 Po1arization ・:.:;(1) 'Cathode ・O ' .・
b:;・;工n'order-仁 odiscuss thevariation:ofs.lag'characterist，ic，s，by，thecurr:己nt ~"conduction'， 100V，was，"app1iedas a'step.functionand.ahomogeneous dis.charge was'realized'~ No changei.could be observed on，th~ current，(and，cat，hode'dro，p for
'the bare:meta1'e1ectrode as 'a'.function of'，time'after，仁he vo1cage was.applied.
i'On.，theotherhand~o;the slaggedcathodes'off1yashand.S，% K2S04・ adde.4 JEhO W
che sl匂
， 649
，'
~lectrode :'
observation
，
val-ue~ sh~.wn
set as ヒhe
-
、
、 .‘
.， -a
t
，
、a，‘ ，
'