CHEMICAL
t M E T A L L U R G I C A L
ENGINEERING
ESTABLISHED 1902 S. D. KIRKPATRICK, Editor
JUNE, 1940
R E S E A R C H - O U R G R E A T E S T R E S O U R C E
C aB R M A N Y d u rin g the p ast few years has been busy su b stitu tin g “ research for resources.” As a w ar-torn world knows only too well, she has ru th lessly used all the techniques and knowledge th a t modern science and in d u stry had to offer. That, on top of a terrific drive for production efficiency and intense concentration on the one job of m ilitary preparedness, probably accounts as much as an y th in g else fo r the an nihilating progress of the Germ an w ar machine.
W e have no desire in this country to create any such F ran k en stein or to regim ent all of our energies and resources into prep aratio n for a w ar of aggres
sion. B u t in organizing our own national defense program we would be worse th an blind if we did not.
see a lesson in the com parative perform ances of Germ any and the Allies. W hat was it th a t most seriously handicapped E n gland and F rance d u rin g the years th a t Germ any was building her w;ar machine? I t was p rim arily a breakdown in the technology of invention and production. W e sus
pect, too, th a t polities and so-called social reform s were perm itted to d istract them from th eir main objective. E n gland had her left-w ing labor troubles, F ran ce her sit-down strikes, 30-hour weeks and nationalization of industries. No wonder technical progress was slow and faltering. No wonder the Allies went into battle w ith little b etter th an first W orld W a r equipm ent. Politics is an impossibly heavy burden on the back of industry, especially in w'artime.
W e have been told th a t in Germ any the govern
m ent called into council all of the leaders of the various industries. They were given sufficient of the plans to know w hat was expected of them and then they were asked—or forced— to supply the best scientific knowledge and production experience they could bring to bear on the problem a t hand. They were especially encouraged or instructed to p u t th e ir best research men and engineers on the job of developing new m aterials, new techniques and
new* machines. T heir work was rem arkably coordi
nated and organized into a g re at m aster plan. A nd ap p aren tly nothing was allowed to stan d in the way of the efficient execution of th a t plan.
Only in case of dire necessity would Am erican ind u stry accept such regim entation by governm ent dictation. B u t w7e believe there can and should be more effective coordination and fu ller use of our vast industrial resources. The greatest of these is research, which if prop erly encouraged and sup
ported can be of inestimable value in our p re p are d ness program . No nation, not even Germany, has the technical manpower, the research laboratories or the engineering facilities th a t we have here. A nd a m an like Compton, K ettering or W eidlein should be able to organize them in the public interest, prom ptly and efficiently and w ithout any question of political dominance or influence.
The p a tte rn for much of the work ahead of us has already been worked out. W e have dem onstrated that, if necessary, we need not be dependent on any foreign source fo r nitrogen, potash and iodine.
More recently rubber has been added to this list as duP ont, Goodrich, S tan d ard Oil, Dow and others reveal the results of th e ir latest researches. New sources of toluol for TN T and glycerine fo r dy n a
m ite are aw aiting full-scale development. Lacquer and resin finishes, paper and plastic containers can conserve or replace our tin supply. So on down the list of strategic and critical m aterials th a t one a fte r another have yielded to A m erican research.
' P resident Collyer of Goodrich, in his announce
m ent of the first commercial automobile tire to be made from all-Am erican raw m aterials, expressed his confidence th a t “ the A m erican public can be relied upon to dem onstrate this tru th — that free
men, cooperating voluntarily, can solve our n a tio n ’s problem s.” There is the answ er to an y th re a t offoreign suprem acy in science, technology or indus
try . L e t’s get behind a program to substitute
“ research fo r politics.”
AN IMPORTANT DISTINCTION
IN CHEMICAL PREPAREDNESS Ma k i n g Am e r i c a r e a d y
for any m ilitary em er
gency involves much of chemical preparedness.
As in the case of mechanical equipm ent, there are two distinct types of requirem ents. Some goods and some machines are needed th a t have no peace
time counterpart. O ther goods and other machines are reg u lar peace-time commodities and devices p u t to m ilitary application, often with little or no modification from th eir ord in ary forms.
There is no sharp line of distinction between the two groups, but it is usually no t difficult to classify specific commodities. F o r example, T.N.T.
has relatively little peace-time application, but trem endous m ilitary im portance. S ulphuric acid lias large war-time usage, bu t it is not p rim arily a m ilitary commodity. I n the field of .m echanical devices, one would find in the m ilitary class things like a n ti-a irc ra ft and anti-tank guns, machine guns, and other weapons an d specialized devices like tanks. B u t there are m any other things like arm ored cars, tractors, an d special motorized equipm ent th a t are m erely modified forms of peace-time autom otive equipm ent.
The distinction between the two classes of goods in which chemical engineers are interested is more th a n academic. I t should have a very practical sig
nificance in determ ining the method by which this country will make its necessary preparation.
L e t’s see how the two classes of goods can be prepared for m ilitary use by two very different systems. F o r this purpose let us take T.N.T. and the two raw m aterials from which it is made, ammonia and toluol. H ere is the way the govern
m ent m ight logically reason:
In d u stry can expand capacity fo r the m anufac
tu re of toluol and of ammonia very considerably a t not too great a cost for new capital. I f assured of a substantial m arket now and potentially very g re a t m arket later, it is logical th a t the m anufac
tu re rs of these goods should get ready to supply them in adequate volume even for m ilitary emer
gency periods. There m ay be need fo r some in
FRO M AN
direct subsidy or some assurance of m arkets for a certain period. B u t the governm ent does not need to p u t up the money, build the plants or man them. Chemical enterprise can do this better, cheaper, quicker. Uncle Sam needs his energy elsewhere. H e should, therefore, leave these jobs
to the chemical corporations.
There is no com parable need fo r commercial establishm ents to make T.N.T. The government should therefore p u t up the money by which suitable plants can be designed and built w ith the expectation of perm anent governm ent owner
ship. In d u stry should be asked only to insure th a t there are skilled, trained, experienced men who are capable of operating these plan ts and who m ay be taken over by the governm ent in case of emergency. I t is ra th e r u n im p o rta n t w hether the operation be by such experienced in d u strial men h ired by the governm ent or w hether some corpora
tion by contract becomes the operator using such personnel. The p oint is th a t the financial obliga
tion for the investm ent is governmental. A nd only the responsibility fo r the availability of tra in e d m anagem ent and senior o p eratin g p e r
sonnel should re st on industry.
Presum ably in this T.N.T. p la n t would be in cluded capacity fo r converting ammonia into n itric acid. I t would be m uch b etter to have th a t con
version capacity a t the p o in t of use of the acid and u n d e r governm ent ownership. I t would have little peace-time significance b u t g re at m ilitary im portance. And, of course, also it would be necessary fo r the governm ent to provide suitable tran sp o rta tio n facilities, probably tan k cars, for moving the am m onia and the toluol from point of production to the T.N.T. p la n t fo r use. The exist
ence of these specialized tan k cars of capacity beyond peace tim e need should be insured a t gov
ernm ent expense. Then if they are idle in peace time, they are of no g reater economic significance th a n idle artillery , bombers, or tanks which all will hope can stay indefinitely garaged at some arsenal.
I f chemical executives w ill go over the problems associated with commodities in which th eir com
panies are interested, they will probably be able to classify most of them in one or the other of the groups described by the foregoing examples.
They will probably be able to figure out how they can do th e ir reasonable share w ithout excessive
392 • J U N E 1 9 ’,0 . CHEMICAL & METALLURGICAL. ENGINEERING
ED ITO R IA L V IE W PO IN T
financial risk on the p a r t of th eir companies. A nd they will be able to work out a definite production program to be subm itted to m ilitary authorities a t the p ro p e r tim e to show th eir readiness.
A ll this discussion is probably an oversimplifi
cation of a very difficult set of problems. B u t it does illu stra te an im p o rtan t basic principle too often overlooked in the W orld W a r and almost altogether ignored lately. I f each company will p rep are to do its p a rt, then all interested com
panies in collaboration w ith the m ilitary authori
ties will be able to work out an understanding as to location, capacities, methods, financing and other im p o rtan t factors by simple, straightforw ard exchange of views. On the basis of such m utual understanding, it ought not to be difficult to give the new Council of N ational Defense assurance with respect to those commodities fo r which chem
ical executives are responsible.
CHEMICALLY SELF-SUFFICIENT
Ch e m i c a l i n d u s t r y
has a large responsibility in the effort to make Am erica more n early inde
pendent of supplies from the re st-o f the world.
R egardless of willingness to trade, there is only restricted o p p o rtu n ity for foreign commerce.
Chemical in d u stry must, therefore, be prepared to su p p ly from domestic sources all of the m aterials commonly brought from abroad.
As it accepts this responsibility, the chemical in d u stry can rig h tly ask its customers to accept some share of the risk and the burden. One recent response of chemical users shows an a ttitu d e which is n o t p ro p e r on the p a r t of chemical purchasers.
The case occurred in the m atch business. A small firm was clam oring fo r potassium chlorate. I t was u rg in g every chemical m aker to produce this fo r its u rg e n t needs. I t agreed to sign a contract for needed su pplies; b u t it was fra n k enough to say th a t it would buy from the cheapest source
“ regardless of co n tra ct.” Obviously negotiations broke down a t th a t point.
There are no t m any chemical raw m aterials u rg e n tly needed in this country which m ust come from abroad. Specialties, yes; b u t stan d ard staple commodities, very few. This is fortunate. B u t for those commodities which A m erican users wish to have A m erican firms produce in this emergency period they should pay p roperly and agree to
stay w ith their new supplier fo r some time to come.
I t is not profiteering for the producer of such chemicals to ask th a t a substantial share of the new capital so risked be re tire d prom ptly. Those lacking raw m aterials of a chemical sort m ust expect tem porarily to pay a b it more. T h at is only their share of the burden of establishing a perm anent economic supply w ithin the U nited States. U ltim ately the cost will be no greater th an from foreign sources using cheap labor.
I t is to be hoped th a t chemical buyers will accept properly th eir p a r t of the responsibility in m aking America reasonably self-sufficient with respect to all im portant chemicals.
A BETTER PRICE INDEX
Pr o d u c e r s a n d u s e r s
of chemicals have for m any years noted w ith some disappointm ent th a t the governm ent’s chemical price index has often varied out of harm ony w ith ap p a re n t conditions in the m arket. I t is a real satisfaction, therefore, to have d u rin g A pril arid May an entirely new chemical price guide from the B ureau of Labor Statistics. I t is evident th a t the new index, which has been established by. the wholesale price divi
sion, is much more closely in accord with actual m arket conditions.
I t is a m atter of satisfaction to note th a t the B ureau staff has had the experienced assistance of the staff of the M anufacturing C hem ists’ Asso
ciation. The new commodity list on which the chemical price index is to be based is f a r more significant th an any previous governm ent effort.
A nd it is fo rtu n a te th a t the related groups of commodities, drugs, fertilizer m aterials, mixed fertilizers and so fo rth are wisely selected, and th a t these groups are segregated from the tru e chemical list.
W e of Chem. & Met. have another reason for satisfaction in this new chemical price index. We find th a t the recalculations made by the govern
m ent extending back to 1926 follow very closely our own price index as we have been issuing it for n early tw enty years. The B ureau averages seldom d e p a rt more th an one single point from the
Chem. & Met. index of the p a st several years. Wejoin w ith the in d u stry in welcoming the new index as an authoritative and official reference base of p roper significance.
CHEMICAL & METALLURGICAL ENGINEERING • J U N E 10!,0 393
.Through
In h elp in g to d ed ica te Purdue U n iversity's fine n e w b u ild in g for its School of C hem ical an d M etallu rgical E ngineering, the editor of C h e m . & Met. d raw s a n in terestin g p a r a lle l in d ev elo p m en ts w ithin le a ch in g a n d pub lish in g, citing opportunities for greater service.
T
h e s e a r e c h a n g i n g, challenging, critical times. E verything we do or say, hope or p lan for, is p red icated on the preservation of our ideals fo r a free people. I t is quite fitting, therefore, th a t we should think of this occasion in term s of service to ou r fellow men, to our scientific and engineering p ro fes
sions, and through them, to our com
munity, state and country. Viewed in such light, this m eeting takes on a deeper purpose. I t becomes p a r t of E ngineering’s broad program fo r
“directing the forces and m aterials of nature to the benefit o f m ankind.”
Above the door of this great build
ing stands, in bas-relief, a most in
teresting design. W e see a blast furnace and a filter press, an auto
clave and an acid tank car, the crossed alembics of the ancient al
chemist and the challenging torch of knowledge and progress. S u rround
ing these symbols of chemical and m etallurgical engineering are fo u r simple, significant words— “ Service - Through Chemical Change.”
W h at better creed is there to ex
press the fundam ental purpose of our w ork and th a t o f ou r profession?
W e serve a g rea t cause, and a sound one, in advancing the application of chemical and physical sciences to the problems o f A m erican industry. As a profession we are com paratively
young, but in the last few decades we have grow n rap id ly in strength and influence. W ith th a t grow th has come great opportu n ities as well as responsibilities.
M ay I illustrate the progress of chemical and m etallurgical engineer
ing during this period by briefly citing some ra th e r intim ate history?
Shortly a fte r the tu rn of the p res
ent century a small group o f chemists and electrical engineers foresaw a g rea t potential development o f elec
trochemical in d u stry a t N iagara Falls. In A pril, 1902, they founded the A m erican Electrochem ical So
ciety and shortly th e re a fte r were instrum ental in establishing a new technical jo u rn al called E lectrochem i
cal Industry. W ith in two years th a t magazine had outgrow n the narrow scope of its title because m any im por
ta n t electrom etallurgical developments were already claim ing its attention.
So the name was changed to Electro
chemical and M etallurgical In d u stry and fo r eight years it survived even such a tongue-tw isting title. B y 1910, however, it had become increasingly evident th a t the industrial ap p lica
tions o f chem istry and m etallurgy were dependent on engineering. So again the name was changed, this time to M etallurgical and Chemical Engineering. F o r seven years and in keeping with the dom inant trend
in Am erican industrial development, m etallurgical engineering was in its ascendancy. Then came the W orld W a r in which the chemical engineer received his b aptism of fire, to emerge and build, w ith the help of the m etallurgical engineer, a new profession and service to industry.
H ence no one objected seriously in 1918 when M et. & Chem. became Chem. & M et.
All this finds a strik in g p arallel in P u rd u e’s School of Chemical and M etallurgical E ngineering. A t the tu rn o f the century a young electro
chemist was contributing his share to the development of the first and greatest electrom etallurgical industry a t N iag a ra F alls. H e served as su
perin ten d en t and director of the laboratories fo r the P ittsb u rg h R e
duction Co., which was then pioneer
ing the production o f alum inum by the H all process. W hen in 1903 its name was changed to th a t o f the A lum inum Co. of America, H a rry Creighton Peffer became superin
tendent and director o f research fo r its alum ina p la n t in Illinois. H e ably discharged these duties in indus
try but all the while he was prim arily interested in teaching and in 1911 he welcomed the invitation to help P u rd u e in establishing its School of Chemical E ngineering.
P rofessor Peffer was given space in the basem ent o f the old Chem istry Building, b u t he liked it down there and in 12 years his g rad u a tin g classes had increased five-fold. M any o f his men are today the recog
nized leaders in A m erican industries.
B y 1923 the old basem ent q uarters o f the “ cellar r a ts ” w ere outgrow n and new space was found in P u rd u e H all. A t the same time, P rofessor J . L. B ray, who had sp en t 12 years in m etallurgical work in this country and in several South A m erican coun
tries, was invited to establish a m etallurgical option in P u rd u e ’s School o f Chemical E ngineering.
M etallurgy’s success paved the way fo r a new course o f instruction in gas engineering in 1928. P rofessor F . L.
Serviss came in 1929 to expand the
394 J U N E 191,0 • CHEMICAL & METALLURGICAL ENGINEERING
m etallurgical instruction led P resi
dent E llio tt and the B oard o f T ru s
tees in 1938 to approve a new curriculum and the g ra n tin g o f a new degree in M etallurgical E n g i
neering. Then came the change in name to the School o f Chemical and M etallurgical E ngineering and the recognition represented by this fine stru ctu re so adm irably equipped fo r u ndergraduate instruction and g rad u ate research.
These splendid facilities are w orthy of the fine trad itio n o f P u rd u e ’s School o f Chemical and M etallurgical Engineering. They add purpose and m eaning to th a t creed o f “ Service Through Chemical Change.” More and more in the fu tu re the indus
tries o f In d ian a and of the nation are going to look to this school fo r help and guidance. Chemical changes underlie so m any in dustrial processes th a t most of the m an u factu rin g in dustries o f the world are to some degree dependent upon chemical and m etallurgical engineering. Public health and protection from disease are chemical responsibilities. New m aterials, new techniques and new industries are the products o f chemi
cal change. A nd great as are all these peace-time contributions, there is no stronger arm o f the n ational de
fense than will be found in the indus
tries and individuals who em brace the professions o f chemical and m etal
lurgical engineering.
So, as we face the uncertainties o f the fu tu re , let us be proud o f our heritage and w orthy to shoulder the im p o rtan t responsibilities th a t will be demanded of us. W hether our work is in the laboratory o r the p lant, in engineering or business m anagem ent, we can be th a n k fu l th a t we have been trained fo r service through chemical change. I t is the greatest o p p o rtu n ity o f all— a chal
lenge to create the things th a t will make the w orld a better, sa fe r and healthier place in which to live.
F o r all these reasons P u rd u e U ni
versity is fo rtu n a te in th a t it has built so soundly and provided so well fo r w hat the late Jo h n H ays H am m ond has called the “engineer
ing of the fu tu re .”
Chemical engineering, m ore th a n any other, m ay be called the engineering of the fu tu re . . . . The chemical engineer stands to day on the threshold o f a vast virgin realm ; in it lie the secrets o f life and p ro sp erity f o r m an
kind in the fu tu re o f the world.
C hem ical C hange
This new four-story building lor the School of Chemical and Metallurgical Engineering at Purdue w a s dedicated June 15 during the Fifteenth Mid- W est Intersectional Meeting of the American Chemical Society. Costing more than SGOO.DOO it Is unusually w ell equipped for engineering studies
work in geology and P rofessor R. N.
Shreve arrived in 1930. The la tte r’s course in organic technology opened an im p o rta n t and ra p id ly developing field o f chemical engineering and g rea tly stim ulated g rad u ate study, which had been sta rted in 1921. To
day th ere are 43 g rad u ate students in chemical engineering w ith 17 w orking tow ard th e ir doctorates.
W ith 50 seniors and a p ro p o rtio n ate num ber o f under-classm en in
1934, the school had once more out
grown its q uarters before new ones could be provided. So it followed Mechanical E ngineering into Heavi- lon H all, while plans fo r this new home were being carefully form u
lated and p ray e rfu lly suggested to the authorities. U nfortunately, P ro fessor P effer did not live to see them consummated. A year a fte r his death in 1934, he was succeeded by P ro fes
sor B ray whose success in developing
CHEMICAL & METALLURGICAL ENGINEERING • J U N E 19/,0 •
R. L. MURRAY,
Hooker Electrochemical Co., N iagara Falls, N. Y.A lkali-C hlorine D evelopm ents
— -— — — Chem . & M et. I N T E R P R E T A T I O N ... — —
There h a s b e e n a rapid in cre a se in the num ber of op eratin g chlorine p la n ts in the U nited States, an d the industry is still grow in g. The am m on ia-sod a industry m et this in cr ea sed com petition from electro
lytic producers b y g o in g into the chlorine b u sin e ss th e m se lv e s. Dur
in g this period of e x p a n sio n nu m erou s im p rovem en ts h a v e b e e n m a d e in production. M ethods for coolin g, drying, purification an d liq u efaction of chlorine h a v e b e e n im proved. The trend in cau stic evaporation h a s b een tow ard higher purity of product an d stea m e co n o m y through higher rates of h ea t transfer. A nother recent d evelop m en t is the d ep o sited d iap h ragm cell. In d ication s are that m ore chlorine w ill shortly b e produced b y it than b y a n y other on e m ak e of d iap h ragm c e ll in this co u n tr y .— Editors.
T
h e e l e c t r o l y t i c Al k a l i i n d u s t r y in the U nited S tates today comprises 42 sizable plants in 17 states plus several small installations fo r hypochlorite m anufacture. A t least 56 establishm ents have existed at one time or other during the course o f this development. In general, those p lants which began prim arily as p ro ducers o f alkali and chlorine have survived and developed into im porta n t factors in the chemical industry.
F ig. 1 shows the com paratively rap id increase in the num ber o f op-, eratin g chlorine p la n ts in the United S tate s; it shows th a t p articu la rly large increases occurred about 1916- 1917 and th a t the industry is still expanding. M any different types of cells have been employed in these installations.
I t has been impossible to obtain complete and accurate statistics on the production of chlorine in the United States, but F ig . 4 has been compiled from m any different sources and is a t least fa irly indicative of the grow th in chlorine production ca
pacity in the U nited S tates. I t seems reasonably certain th a t d uring
B a s e d o n a p a p e r p r e s e n t e d b e fo r e th e N ia g a ra F a l l s m e e tin g o f t h e A m e r ic a n I n s t i t u te o f C h e m ic a l E n g in e e r s t M a y 1 8 - 1 5 , 1 9 ^ 0 .
p a r t of 1937 and tow ard the end of 1939 this production capacity was nearly all utilized.
F ig. 3 show's the location of all of the im p o rta n t chlorine producing p la n ts in the U nited S tates. Small installations fo r the production of sodium hypochlorite, o f which there are several, have n o t been included.
The symbols on the m ap differentiate the plants according to general ty p e o f cell used, nam ely, m ercury, fused salt, soda ash, or diaphragm , and indicate w hether the p la n t is o p erated in conjunction w ith either a soda ash p la n t o r a p u lp mill. The large circles show the p rin cip al chlor
ine producing centers in the U nited States, the areas o f these circles be
ing roughly indicative of the tonnage of chlorine produced in the p a rtic u la r locality.
A n interestin g sto ry could be told about the increasing production of electrolytic caustic soda in com pari
son w ith the production o f ammonia- soda caustic soda. F ig. 2, compiled from figures given in U. S. Census rep o rts and Chemical and M etallurgi
cal Engineering, shows the relation
ship between the production o f am monia-soda caustic soda on the one
h and and electrolytic caustic soda on the other. The am m onia-soda indus
tr y met this increased com petition from the electrolytic producers by going into the chlorine business them selves. Since 1926, six p la n ts fo r the production of electrolytic caustic soda and chlorine have been built in conjunction w ith soda ash plants.
The first was th a t o f Solvay Process Co. a t Syracuse, followed by Diam ond A lkali Co. a t Painesville, O h io ; Sol
vay a t B aton Rouge, L a .; Columbia Chemical division of P ittsb u rg h P late Glass a t B arberton, O hio; Southern A lkali Corp. a t its new soda ash plan t a t C orpus Cliristi, T exas; and M ichi
gan A lkali W orks a t W yandotte, Mich. M athieson A lkali has its elec
trolytic p la n t located se p arate ly from its soda ash plants. Two im p o rta n t fac to rs in the grow th o f chlorine p ro duction in these plants have been the availability of brine from existing supplies and the development of high pressure steam generation and bleeder turbines, which makes cheap powTer available as a b y product o f steam generation fo r process uses.
I t is not to be expected th a t the resulting com petition fo r the avail
able chlorine m arket between the soda ash chlorine producers and the non
soda ash chlorine producers wras car
ried on w ithout a ra th e r drastic r e duction in the price o f chlorine. F ig.
5 shows the listed m arket prices of chlorine since 1921. This d rastic low
erin g in the price o f chlorine has g reatly stim ulated its use and has been an im p o rta n t fa c to r in the grow th of its consum ption.
A lthough not electrolytic chlorine, it would be an oversight to fa il to m ention Solvay’s developm ent of chlorine production as a byproduct o f its huge n itrogen fixation p la n t a t Hopewell, Va. Reduced to its fu n d a
mentals, this process involves the p ro duction of chlorine and sodium n itra te from salt and nitrogen fixed from the air. V ery .serious technical and chemical engineering difficulties
3t)G • J U N E 1.0!,0 . CHEMICAL & METALLURGICAL ENGINEERING
Type "S" cells in the Tacoma, W ash., plant of Hooker Electrochemical Co.
have had to be overcome in its de
velopment. A study o f the fu n d a m ental economics of this process as a com petitor o f electrolytic processes f o r the m anufacture o f chlorinc would be very interesting, b u t is be
yond the scope of this article.
The availability of salt is all im p o rta n t in the production of electro
lytic alkali and chlorine. Rock salt, brine wells and salt domes and salt fro m solar evaporation of sea w ater rep rese n t the im p o rta n t sources and the developm ent over the p a s t fo rty o r fifty years o f brine wells and long p ip e lines fo r brine tran sp o ra tio n has been noteworthy. D istance seems no b a rrie r and a t least one pipe line f o r conveying- brine fo r alkali and chlorine production exceeds 50 miles in length. The m ining o f rock salt has also undergone im provem ents un
til such sa lt is now available to near-by electrolytic producers a t a cost only slightly higher than the cost of brine from wells when the capital cost fo r the developm ent o f such wells and the cost o f pip e line to tra n s p o rt the brine are taken into account.
S olar salt p a rtic u la rly from San F rancisco Bay, has been of vital im portance in the developm ent o f the electrolytic alkali industry on the Pacific Coast. The tra n sp o rta tio n of this solar sa lt in large boat loads is w orthy o f m ention.
A long w ith the delivery o f salt, either as brine or as solid salt to the electrolytic p lant, real im provements have been developed in the purifica
tion o f brine fo r electrolytic p u r poses. This is im p o rtan t because this p u rity has a m arked influence on the efficiency and cost of the electro
lysis which follows. No diaphragm cell has yet been developed which electrolyzes efficiently more than about half o f the salt fed to the cell.
D uring the concentration and purifi
cation o f the caustic liquor, the resi
dual salt is recovered and returned to the process. The recycling o f the salt results in an accum ulation in im
purities, especially o f sulphates in the brine. A num ber of im proved methods have been developed to re move these im purities from the process.
Advances have been made in the a rt o f generating power and con
v erting altern atin g to direct current during the p a st 30 years. M ercury are rectifiers of various types are now being used in several p la n ts in p r e f erence to m otor g enerator sets or r o ta ry converters. Few, if any, m otor generators o r ro ta ry converters have been discarded, unless worn out, to be replaced by rectifiers, b u t p la n ts which have been built recently have installed rectifiers. The capacity and num ber of cells involved are im por
ta n t fac to rs in this situation, since rectifiers are less efficient a t low total circuit voltages and can only be used economically when they can operate a t higher voltages. The development o f high pressure steam g enerating plants and bleeder turbine pow er has already been m entioned and has been a real influence in the grow th o f the electrolytic alkali industry.
M ethods fo r cooling, drying, purifi
cation and liquefaction o f chlorine have been im proved. The cooling of hot, wet, chlorine gas down to 12 to 14 deg. C. which ju s t avoids the form ation o f solid chlorine h y drate which would cause plugging o f pipe lines, is done in several ways. Some o f these a re : stonew are chlorine lines submerged under w ater in trenches;
stonew are disk coolers; w ater cooled glass p ip e s; and ru b b er lined steel pipes. The cooling is done either w ith o r w ithout refrigeration, de
pending on available w ater tem pera
ture and the cost o f sulphuric acid.
D rying is done w ith sulphuric acid in stonew are o r leadlined, steel d ry ing towers and also in stoneware tourills which have a higher invest
m ent cost but are somewhat more economical to operate.
C orresponding advances have been m ade in the com pression o f chlorine, the compressor's being alm ost in v ari
ably the m eans o f creating the suc
CHEMICAL & METALLURGICAL ENGINEERING • J U N E 19!,0 397
tion which w ithdraw s the chlorine from the cells. B roadly speaking, there are two main methods— one em
ploying the use of centrifugal sul
phuric acid sealed com pressors such as N ash hydro turbines which com
press the chlorine to a ra th e r modest pressure (15-30 lb.) and the other involving various types o f reciprocat
ing compressors, most o f them sul
phuric acid lubricated o r sealed, which go up to a considerably higher pressure, such as 75 lb. or more.
T he necessary refrig eratio n to liquefy the compressed chlorine is done in single stage and m ultiple stage; ammonia, carbon dioxide and F reon are the refrig e ra n ts generally employed. The economic balance be
tween com pression o f chlorine with single or m ulti stage refrigeration, and the refrig eran t to be used, in volves questions such as power con
sum ption and the cost of power, liquefaction efficiency required, and the usual balance between continued em ployment o f already existing equipm ent versus its replacem ent by new equipm ent of an im proved type.
Mention is here made o f the Pennsyl
vania S alt C om pany’s interesting method o f chlorine purification by passage o f the chlorine to be lique
fied counter-current to liquid chlorine in a bubble cap column.
The trend in caustic evaporation has been tow ard higher p u rity o f product and steam economy through higher rates o f heat tran sfe r. The development of the use o f nickel tubes, nickel o r nickel arm ored steam chests and nickel o r nickel clad vacuum p an s and pum ps has been noteworthy and is now fa irly sta n d ard practice. The use o f forced cir
culation as applied to electrolytic caustic beginning about 1927 afforded higher rates o f heat tra n sfe r through the tubes and made possible the use of sm aller tubes and, therefore, less investm ent in nickel. M any com bina
tions o f evaporators are used in elec
trolytic caustic evaporation but the reverse flow trip le effect w ith forced circulation is now generally con
sidered the most efficient arran g e
ment.
F o r m any years electrolytic caustic soda was in ferio r in quality to am- m onia-soda caustic soda. However, developments over the p a s t 15 years have resulted in the production of high p u rity , low -salt electrolytic caus
tic soda so th a t a substantial tonnage o f electrolytic caustic soda in liquid form is now being used w ith satisfac
tion by viscose rayon m anufacturers.
There is now electrolytic diaphragm cell caustic soda available in large
398
tonnage which is quite equal in qual
ity to the caustic soda produced by the ammonia-soda process. Among others, the w ork of A. H . H ooker was outstanding in the development o f methods of high grade electrolytic caustic soda production.
The economical recovery and u ti
lization of the hydrogen obtained as a coproduct from the electrolysis of sa lt solutions has seen substantial de
velopment and m any of the elec
trolytic plants are now utilizing the la rg e r p ro p o rtio n of the hydrogen which they produce. S ynthetic am monia, the production of synthetic hydrochloric acid by b u rn in g w ith chlorine, the hydrogenation of oils,
and the production o f various chemi
cals by high p ressure hydrogenation are some o f the ways in which elec
trolytic hydrogen is employed.
A ny review of the chlorine indus
try would be incomplete w ithout men
tion of the outsanding developments in liquid chlorine containers and in methods o f tran sp o rta tio n . Single unit ta n k cars were em ployed as early as 1909 by the Pennsylvania S alt Co.
Since then, chlorine ta n k cars have been im proved in design and in creased in capacity. The development o f the “ ton container” by M auran and Rowland and the shipm ent of these containers on the so-called m ulti-unit underfram e car has been
NUMBER 4 5
4 0
35
30 2 5
20
15
10
5
| g ^ 1900 1910 1020 1930 1 9 4 0 Y E A R
Fig. 1
T O N 5 P E R Y R .
5 0 0 ,0 0 0
400,000
3 00,00 0
200,000
100,000
• J U N E 191,0 • CHEMICAL & METALLURGICAL ENGINEERING PRODUCTION OF AMMONIA SO DA A N D ELE CT RO LY T IC
CAUSTIC SODA IN U N IT ED STATES — BY Y E A R S DOES NOT INCLUDE P U L P M I L L P R O D U C T IO N
C O N S U M E D IN P U L P M I L L S
FROM U.S.CENSUS O F M F G S.& C H EM .A MET. E S T IM A T E S
L E G E N D
Wm E LE C T R O LY T IC NoOH r777\ AMMONIA SODA NoOH
1921 1923 1925 1927 1929 1931 1933 1935
Fig. 2
1937 19 3 8 N U M BE R OF O PERATING C HLO R IN E P L A N T S
IN U N IT E D S T A T E S — BY Y E A R S (D O E S NOT INCLUDE S M A L L P L A N T S
-PRO D U C IN G H YPO CH LO RITE]
r
an interestin g and im p o rta n t contri
bution to the industry. A ccording to Chlorine In stitu te records, there are now about 950 single u n it cars and 270 m ulti u n it underfram es in use in the U nited S tates fo r the tra n sp o r
tation of liquid chlorine. The T est &
Specification Committee o f the In s ti
tute, together w ith the engineering staffs o f the various producers, both In stitu te members and non-members, have played an im p o rta n t p a r t in this development and in the w onderful safety record which has been built u p on the shipm ent o f chlorine over the last q u a rte r of a century.
The la st few years have seen a g re a t increase in the production and
(Please turn to page 409)
O PERATING CHLORINE PRODUCING P L A N T S IN UNITED S T A T E S - 1 9 4 0
• IM J O U E C A S E S K O H
>KEY:
O C H L O R IN E D IA P H R A G M C E L L S IN S O D A A S H P L A N T S
C H L O R IN E A N o O H D IA P H R A O M C E L L S N O T IN S O D A A S H P L A N T S
M E R C U R Y C E L L S IN S O D A A S H P L A N T S M E R C U R Y C E L L S N O T IN S O D A A S H P L A N T S F U S E O S A L T C E L L S
H A R 0 R E A V E S - 8 IR 0 C E L L S C H L O R IN E i. SODA ASH N IT R O SY L C H LO R ID E P R O C E S S FO R C H L O R IN E DO UB LED O U T L IN E - P U L P M IL L P L A N T I IN D IC A T ES C H L O R IN E CAPACITY FOR LO CALITY
W H E R E O V E R Z i T O N S P E R DAY
Fig. 4
Fig. 3 1— Brown Co., B erlin, N. H .
2—-Mathieson A lkali W orks, N iag ara F a lls, N. Y.
3— S. D. W arren Co., Cumberland, Me.
4— Dow Chemical Co., M idland, Mich.
• 5 —N iagara A lkali Co., N iagara P alls, N. Y.
6— Pennsylvania S a lt Mfg. Co., W yandotte, Mich.
7— D. M. B are Pap er Co., R oaring Spring, P a.
8— W est V irginia Pulp & P a p e r Co., Piedm ont, W. Ya.
*0— W estvaco Chlorine Products Corp., South C harleston, W. Va.
10— Hooker Electrochem ical
N. Y. Co., N iagara F alls,
11— W est V irginia P ulp & P a p e r Co., Mechanic- ville, N. Y.
12—W est V irginia P ulp & Pap er Co., Tyrone, Pa.
13— W est V irginia Pulp & P a p e r Co., Covington, Va.
14— C astanea P a p e r Co., Johnsonburg, Pa.
15— Gulf Oil Corp., P o rt A rth u r, Tex.
Dow Chemical Co.,
*10— G reat W estern Division P ittsb u rg , Calif.
17— Penobscot Chemical
Me. F iber Co., G reat Works,
Fig. 5
18— Oxford Pap er Co., Rum ford, Me.
19—N iagara Sm elting Corp., N iagara F alls, N. Y.
*20— Iseo Chemical Co., N iagara F alls, N. Y.
21— E. 1. du P o n t de Nemours & Co., D eepw ater Point, N. J.
22— K im berley-Clark Corp.. K im berly, Wise.
23— E astern M anufacturing Co., South Brewer, Me.
2 4— F ield s P o in t Mfg. Corp., Providence, R. I.
25— E .. I. du P o n t de Nemours & Co. (It. & H .), N iagara F a lls, N. Y.
26— Belle A lkali Co., Belle, W. Va.
27— Champion Pap er & F ib re Co., Canton, N. C.
*28— Solvay Process Co., Syracuse, N. Y.
29— Monsanto Chemical Co., E a s t St. Louis, Mo.
30— Diamond A lkali Co., Painesville, Ohio.
31— Hooker Electrochem ical Co.. Tacom a, W ash.
32— Pennsylvania S a lt Mfg. Co., Tacoma, W ash.
33— Morton S alt Co., M anistee, Mich.
34— P ittsb u rg h P la te G lass Co. (Columbia D ivi
sion), B arberton, Ohio.
35— Solvay Process Co., Hopewell, Va.
36— Solvay Process Co., Baton Bouge, La.
37— Southern Advance Bag Corp., Hodge, La.
38— Southern A lkali Corp., Corpus C h risti, Tex.
39——Champion Paper & F ib re Co., H ouston, Tex.
40— Michigan A lkali W orks, W yandotte, Mich.
41— Hercules Pow der Co., Hopewell, Va.
42— E th y l Gasoline Corp., B aton Rouge, I-a.
* KOH as well as NaOH.
CHEMICAL & METALLURGICAL ENGINEERING . J U N E 191,0 399
P erfect Fits for
HAROLD S. CARD
Consulting Engineer, N ew York, N. Y.4°0 . J O N E 19J,0 • CHEMICAL & METALLURGICAL ENGINEERING
Chem . & Met. I N T E R P R E T A T I O N — — — A great d e a l h a s b e e n p u b lish ed on the tech n iq u e of w e ld in g of p ressu re a n d other v e s s e ls for p ro ce ss in d u stries u se, p o ssib ly g iv in g the erroneous im p ression that w ith proper w e ld in g a ssu red , the other p h a s e s of v e s s e l fabrication are re la tiv e ly unim portant. This is far from true for g o o d w e ld in g cannot offset poor preparation a n d fit-up, w h ich m a y result at b est in a poor a p p e a rin g v e s s e l, a n d at w orst, in on e w h ich is u n sa fe under p ressure o w in g to eccen tricity a n d the d ev elo p m en t of u n an ticip ated str e sse s. This article reports h ow one la rg e fabricating p lan t in su res a p erfect fit-up.—EdHors
S
o m e y e a r s a g o an am bitious a ttem pt was made to weld an ex
tensive installation of stainless steel piping. A fte r a few months o f service the installation fell a p a r t although the welds were all intact, thus proving th a t stainless steel could be welded b u t th a t som ething was wrong. T h at “som ething” turned out to be carbide p recipitation in the p are n t metal n ea r the weld. In the following years a g rea t deal has been learned and w ritten about this im p o rtan t fa c to r in the welding of stainless steels, not only fo r p ip in g but fo r all m anner o f containers. The well inform ed fab rica to r now has little o r no trouble from this cause.
This discussion will therefore deal sparingly w ith the actual welding and focus attention on some mechan
ical aspects of the fabrication p ro gram , w ith p artic u la r reference to alloy vessels whose service conditions call fo r a perfect job.
I f we assume a p erfect fabrication
to be one th a t will operate indefinitely in its service range w ithout failure, we have a concept of perfection which is sufficiently rig id f o r the presen t purpose. A t the bottom of the scale, fo r example, are ord in ary w ater tanks and steel storage bins, which can readily be made to meet mild corrosion conditions by follow ing directions th a t any electrode
m a n u factu rer can supply. F o r such purposes, much o f the costly precision w ork in p rep a ra tio n which is to be described would undoubtedly be u n economical.
A t the to p of the scale are alloy p ressu re vessels fo r the process in
dustries where tem peratures, p re s
sures and corrosion conditions are so severe th a t extrem e m easures m ust
Fig. 1—-On lhis boring mill the dished head is cut to size and the 35-deg. bevel ior welding is formed
Fig. 2— The edge planer is an extremely accurate tool for trimming the shell plates to the exact size required
P erfect W elding
The hydraulic crimping press at the right (Fig. 3) is used the longitudinal seam s before the plate is rolled to the to form the metal at the edges of the plate adjacent to desired finished diameter on the roll at the left (Fig. 4)
be taken to insure safe perform ance and long service life. H ere every operation involved in m anufacture m ust be perform ed w ith more preci
sion and more carefully engineered control th a n is necessary to meet the m ild requirem ents o f ap p earan ce and sanitation, o r sim ply resistance to corrosive action. The w riter lias had an o p p o rtu n ity to observe the fa b ri
cation procedures followed in the p la n t o f E dge M oor Iro n W orks, Inc., a t E dge Moor, Del., and through the courtesy o f com pany officials is p erm itted (o describe them.
The f a c t practically all of the ves
sels fab ricated in this p la n t are sub
je c t to code requirem ents is sufficient to indicate th a t m aterials, operators and deposition techniques used are all o f the first order. F urtherm ore, these are details o f the process qual
ification th a t governs weld quality.
L et us then give atten tio n to the subject o f fit-up, which is occasion
ally mentioned in connection with alloy fabrication, b u t is ra re ly dis
cussed in a n y detail. There is, in fact, some thought th a t a good fit-up is accom plished chiefly by m ounting the work in a jig th a t is strong enough to force p late edges into alignm ent before sta rtin g to weld.
In the E dge M oor fa b ric a tin g divi
sion a good fit-up s ta rts much fa rth e r back th a n that.
F o r the sake o f brevity, let us take the sim plest case, a pressure- vessel composed o f cylindrical rings and dished heads. The plates fo r the head and shell are custom arily
ordered from the same heat, the shell p la te being delivered flat and the heads following a fte r they have been formed. (This, it should- be noted, is a p erfectly norm al and routine delay.) W hen the shell plates arrive a t the p lant, the first step tow ard g etting a p erfect fit-up fo r this class of fab ricatio n is to set them aside and ivait fo r the delivery of the heads. This is necessary because the tolerances commonly allowed in the dim ensions o f form ed heads are g re a te r than the perm issible fit-up tolerance, assum ing th a t the finished vessel is to m easure up to the defini
tion already given of a p erfec t job.
U pon arrival, the dished heads are machine beveled on a boring mill (F ig. 1) to provide the welding groove. A 35-deg. bevel is the usual practice. Then the perim eter o f the edge is taped to obtain exactly the right dimension o f shell to fit it. This procedure is a thorough safeguard against offset joints. I t frequently happens th a t two heads o f the same intended size will tu rn out to vary slightly in diam eter. Such variation is discovered a t this stage of the fabrication and shell diam eters are adjusted to com pensate fo r it; the small am ount o f ta p e r given to the shell being f a r less objectionable than a poor fit a t the welding edge.
N ext comes the shell p late p re p a ra tion. This sta rts w ith the mill order, which has i in. added to all fo u r edges above the net size required.
W hen the final .dimensions have been determ ined from the head m easure
ment, the p la te is laid out, r e squared and the edges are planed as in F ig. 2 and a t the same tim e beveled (35 deg.) fo r the welding groove. (The chromium and nickel alloys o f course require a h arder tool and slower cutting speeds than boiler plate.) The depth o f cut is more than am ple to get below any surface cracks th a t may have been produced in shearing, and so there is obtained a sound and solid base fo r the weld deposit. Gas flame cu t
ting is not used on this m aterial, because o f its crystallizing effect.
A careful check o f the dimensions o f the machined p late is made, then it is considered to be read y f o r fo rm ing. P rio r to the rolling shown in Fig. 4, a pow erful hydraulic crim p
ing press (F ig . 3) form s the m etal adjacent to both edges o f the longi
tudinal seam to the rad iu s o f the vessel. This prevents the out-of- roundness which occurs if plates with flat edges are rolled to c y lin d ers._ A small curvature allowance is made in this pre-form ing operation so th a t contraction o f the weld area will draw the p late in to the exact curva
ture. Skill in the design and con
struction o f fo rm in g dies thus be
comes an im p o rta n t fa c to r in obtain
ing fit-up.
The justification o f all this m eticu
lous attention is two-fold. I n the first place, the welding of this m ate
ria l requires very skillful arc m anipu
lation, which would be appreciably disturbed by variations in the w idth and shape o f the w elding groove.
CHEMICAL & METALLURGICAL ENGINEERING • J U N E 1940 401
given to the heavy sections. I f the vessel is too large fo r imm ersion a w ater sp ray is used fo r the quench.
The use o f columbium as a stabilizing element in chromium-nickel alloys is effective in preventing precipitation, provided th a t the columbium is p res
ent in both the p la te m aterial and the welding wire. S tra ig h t chromium alloys are heat trea ted to 1,550 deg.
F . f o r three hours and allowed to cool slowly. The lighter gages o f the 18-8 alloy are welded w ith a back-up o f ru n n in g w ater o r dry ice, which checks w arping as well as p re c ip ita tion.
One p ro p e rty of the 18-8 group of alloys th a t is frequently overlooked is th a t it w ork hardens, and cold w orking m ay im p air its resistance to corrosion to a considerable extent.
A head th a t has been dished by ham m ering an d then welded to a shell m ay oxidize quite readily out in the plate, even though the weld area is n o t g reatly affected. A tank so fabricated should be h eat treated in its entirety to restore its original m etallurgical properties.
I n the above discussion a sim ply designed stainless steel vessel has been used as an example, and only the sim plest connections have been described. M any such vessels have
Fig. 5— Typical defective joints: (a) out-of-round, and (b) off-set joint
more complex connections a t open
ings, and more in tricate in te rio r com
ponents. T here is therefore no end to the diversity o f m echanical aspects o f fab rication in this field.
The necessity f o r good fit-up is equally g reat when p la te m aterials are other commercial alloys, either ferrous o r non-ferrous. New de
velopm ents in the process industries are leading to dem ands f o r vessels fab ricated from Monel, aluminum, copper, E verdur, etc., each m aterial having its special deposition tech
nique fo r the w elding o p era to r to learn. The universal requirem ent is fo r carefully engineered mechanical procedures to secure p e rfec t fit-ups, in o rd er th a t the w elding technique m ay be applied w ith assurance of p erfec t success.
Fig. 6—Heat treatment for correcting carbide precipitation is accomplished after careful procedure determination based on a study of optimum heating rate
Secondly, it is obvious from a glance a t F ig. 5 th a t offset jo in ts produce uneven stress distributions. I f the two defective procedures illustrated in F ig. 5 are combined in a single vessel the result is an ungainly and probably untru stw o rth y construction.
The p ractical view o f all this is th a t we are considering the fab rica
tion o f vessels involving large qu an ti
ties o f expensive m aterial. Econom y dictates the use o f the sm allest sec
tions th a t will ca rry the loads. Sound weld metal, smooth contours and easy stress distribution are all indispensa
ble factors when minim um p late thickness is used. C ertainly the last two o f these essentials cannot be ob
tained w ith poor fit-up, and even the soundness o f the weld would be open to suspicion by a skilled inspector w herever he detected misalignment.
A fte r rolling to shape, the shell rin g is tack welded rigidly and the longitudinal seam is welded. Then the rin g is fitted to the head. I f there have been no erro rs in the p ro cedure thus f a r , the perim eters of the ab u ttin g edges should be identical in size and shape, b u t if any slight
v ariation in curvature is discovered it can be corrected on the rolls before tacking on the head fo r final as
sembly.
A lthough the em phasis has been placed on these mechanical details o f fabrication, it is n o t desired to underestim ate the im portance o f the welding technique. The argum ent is ra th e r th a t the careful development o f w elding technique is likely to be fu tile in p ro p o rtio n as these me
chanical details are neglected.
W hen definite assurance o f weld soundness is w anted, X -ray exam ina
tion is used in the same m anner as f o r boiler drum s and other code ves
sels m ade from the carbon steels.
The favored m ethod of correcting carbide p recipitation is to heat to 2,000 deg. F . as in F ig . 6 and quench w ithin three m inutes from the time the heat is checked. The presence o f heavy sections makes it a nice problem to determ ine the best ra te o f increasing the heat. B efore heat treatm ent is started, therefore, a study is m ade to be sure th a t no p a r t o f the vessel is skim ped, and in cooling special atten tio n is again
402 • J U N E 1940 • CHEMICAL & METALLURGICAL ENGINEERING
How a n Acetate R ayon P lan t Assures Fire Protection
M. BERNARD MORGAN
Am erican Viscose Corp., M eadville, Pa.... C/iem. & Met. I N T E R P R E T A T I O N
Fire protection in a p lan t e m p lo y in g la rg e q u an tities of fla m m a b le, v o la tile m a teria ls su ch a s a c eto n e n e c e ssita te s a w ell-co n sid ered p la n , su ita b le equipm ent, a n d constant v ig ila n c e in the m a in te n a n ce of the effic ie n c y of the protective installation . Mr. M organ d e scr ib es here h o w s p e c ia lly h azard ou s lo c a tio n s in the M e a d v ille a ce ta te rayon plan t h a v e b e e n protected b y carbon dioxid e, p ip e d to 12 of the p r o cess s p a c e s, a n d a u to m a tica lly controlled b y a n in g en io u s electrical-m ech an ical sy stem . A m a n u a lly controlled carbon d ioxid e sy stem , h an d extin gu ish ers an d sprinklers are a lso u s e d .—Editors
I
NT T H E M AN U FACTURE of C e l lu lo s eacetate y arn s in our Meadville, Pa., p la n t we are faced with fire p ro tection problem s which call fo r spe
cialized extinguishing technique. In m any o f the process rooms and spaces where we p re p a re solutions o f cellulose acetate with acetone and other volatile liquids, the a ir can be
come contam inated w ith a com bust
ible m ixture, because of acetone’s 35 deg. F . flash ¡joint. This hazard exists in all seasons o f the y ea r and a static o r electrical sp a rk can touch off a serious and rap id ly spreading fire.
To com bat this h azard in the spaces w here contam ination w ith combustible fum es is most likely to occur, we have installed high-pres
sure carbon dioxide fire extinguishing systems. T heir function is to p ro vide, w ithin a few seconds a fte r ignition o f v apor m ixture, an atm os
phere in e rt to combustion, and subse
quently to re ta rd o r stop flame pro p ag atio n to adjoining spaces.
These systems have a to ta l capacity o f 5,500 lb. o f carbon dioxide gas and liquid and fo rm w hat is pro b ably the larg est gas fire extinguishing set-up used in any A m erican chemical p lant. They are supplem ented by another 2,000 lb. o f carbon dioxide stored in p o rtable extinguishers, which can be used on localized fires in flammable liquids o r electrical equipm ent when they are discovered in early stages.
O ur largest carbon dioxide system consists o f 94 cylinders, each o f 50 lb. capacity which, together w ith the release mechanism, are housed in a small brick building specially de
signed fo r this purpose and located close to the hazardous spaces in the m ain p lant. This system protects 12 process rooms or spaces, the control being arran g ed so as to give p rotec
tion in the follow ing m anner:
F iv e spaces each to receive the contents o f 94 cylinders.
F ive spaces each to receive con
tents o f 70 cylinders.
Two spaces each to receive con
tents o f 24 cylinders.
This arrangem ent was based on the cubage of the various rooms and p ro vides fo r an autom atic discharge of enough gas to bring the oxygen con
ten t o f the a ir in the spaces down to 14 p e r cent or less— well below the combustion point. In the event of fire in any one of the spaces, the discharge o f gas provides an in ert
lation is m echanical-electrical, and is actuated when an abnorm al r a te of tem perature rise occurs in any space.
Air-filled actuators are located on the ceiling o f each space as in F ig. 1, and are connected through small-bore copper tubing to a trip mechanism which opens the cylinder valves and floods the space w here the tem pera-
Room trip m echanism enclosed/
, Supply piping from
carbon dioxide storage Fig. 1—Typical floor layout at M eadville plant showing ceiling actuators, trip device
and discharge pipes
Shielded discharge nozz/es.i..
W indow release
atm osphere not only in the room where the fire sta rts b u t in adjoining spaces, inasm uch as flash fires can spread to all adjoining spaces.
Control fo r the 84-cylinder instal-
CHEMTCAL & METALLURGICAL ENGINEERING • J U N E 19!,0 • 403
