T h e J o u rn a l of In d u stria l a n d Engineering Ghemistry
P u b l i s h e d by T H E A M E R I G A N G H E M I G A L S O G I E T Y
Volume IV FEBRUARY, 1912 No. 2
BOARD OF EDITORS.
Editor: M. C. W hitaker.
Associate E d ito r s:
G. P. Adam son, E . G. B a iley, H. E . B arn ard, G. E . B arton, A . V : Bleininger, W m . B rad y, C. A . Brow ne, F. B. Carpenter, C. E . Caspari, V . Coblentz, W . C. Geer, W . F . H illebrand, W . D. Horne, T . K am oi, A. D.
L ittle , C. E . L ucke, P. C. M cllh in ey, W m . M cM urtrie, J. M. M atthew s, T . J. P arker, J. D. Pennock, W . D.
R ichardson, G. C. Stone, E . T w itchell,' R . W ahl, W . H. W alker, W . R. W h itn ey, A . M. W right.
P u b lish e d m o n th ly . S u b s c rip tio n p ric e to n o n -m e m b e rs o f th e A m e ric a n C hem ical S o c ie ty , $6.00 y e a rly . F o re ig n p o s ta g e , sev e n ty -fiv e c e n ts, C a n a d a . C u b a a n d M exico e x ce p te d .
E n t e r e d a t t h e Po st-O ffice, E a s to n , P a ., a s S eco n d -class M a tte r.
t a b l e o f c o n t e n t s.
Ed i t o r i a l s:
P o ta sh from th e P a c ific K e lp s ... 76
S u rfa ce C om b u stio n ... 77
P h y sic a l-In d u stria l C h e m istry ... 79
Or i g i n a l Pa p e r s: S om e P rob lem s in C hem ical E n g in eerin g P ra c tic e. M an u fa ctu re a n d T e s tin g of S h ip p in g C ylin d ers for A n h y d ro u s A m m on ia. B y F . W . F re ric h s ... 80
T h e M an u fa ctu re a n d T e s tin g of C arb onic A c id C y lin ders. B y John C . M inor, J r ... 88
T h e C om p osition of S om e M ine G ases, and a D escrip tio n of a S im p le M ethan e A p p a ra tu s. B y G . A . B u r re ll... 96
S a lt-R is in g B re ad and S om e Com parisons w ith B re ad M ade w it h Y e a s t. B y H e n ry A . K o h m a n ... 100
A S tu d y of th e V is c o sity of F ish O ils. B y G eorge F . W h ite ... 106
La b o r a t o r y a n d Pl a n t: H a rd n ess of P la sters and C em ents, a n d a S im p le C hron og rap h ic A p p a r a tu s for R e co rd in g S e t. B y C has. F . M c K e n n a ... n o R e c e n t Im p ro ve m e n ts in F iltra tio n M ethods. B y E r n s t J. S w e e tla n d ... 114
A n E le c tric S till A d a p te d for D iffic u lt D istillatio n s. B y I. C. A lle n and W . A . J a c o b s... 118
T h e C arbo n D io x id e R e co rd er a s a F a c to r in F u e l E co n o m y . B y E . A . U e h lin g ... 123
Ad d r e s s e s: M ineral W a s te s: T h e C h e m ists’ O p p o r tu n ity ... 125
Pe r k i n Me d a l Aw a r d: In tro d u ctio n . B y M. C. W h it a k e r ... 131
P r e s e n ta tio n A d d ress. B y C. F . C h a n d le r ... 132
A d d ress of A c ce p ta n c e . B y H erm a n F ra sc h ... 134
G eo lo g y of th e S u lp h u r a n d S u lp h u r O il D ep osits of th e C oa stal P la in . B y C ap tain A . F . L u c a s ... 140
S u lp h u r M ines of the U n ion S u lp h u r C o m p an y in L o u isia n a . B y F . H . F o u g h ... 143
Sc i e n t i f ic So c i e t i e s: F o rty -fifth A n n u al M eeting A . C. S . P ro g ram of P ap ers 147 M inutes of D ivision of In d u stria l C hem ists and C h em ical E n g in e e rs... 148
M inutes of D ivision of A g ricu ltu re a n d F ood C h em istry 149 M in utes of th e D ivision of P h arm a ce u tica l C h em istry 150 M in utes of M eetin g of F e rtilize r D iv is io n ... 151
M in utes of th e M eetin g of th e R u b b e r S e c tio n ... 152
No t e s a n d Co r r e s p o n d e n c e; N o te on the P ro d u ctio n of M ercu ry F u lm in ate . B y C harles E . M u n ro e ... 152
T u n g ste n P ro d u ctio n in the U n ite d S ta te s in 1 9 1 1 ... 153
C la y P ro d u c ts in 1 9 1 0 ... 153
L e a d I n d u s try in 19 1 0 ... 153
Co n s u l a r a n d Tr a d e No t e s: G erm an P o ta sh In te r e s ts ... 154
N o rw eg ia n G u an o S h ip m en ts to U n ite d S t a t e s ... 154
G lass P a v in g B lo ck s in F r a n c e . ... 154
P a lm -O il In d u s try o f W e s t A f r i c a ... 154
In creased C u sto m s D u tie s in B o liv ia ... 154
Bo o k Re v i e w s: A d d resses to E n g in eerin g S tu d en ts; D ie P o larim e tric der E rd o le ... 155
Ne w Pu b l ic a t io n s... 156
Re c e n t In v e n t i o n s... 157
Ma r k e t Re p o r t... 158
76 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Feb., 1912
EDITORIALS
P O T A S H F R O M T H E ^ P A C IF IC K E L P S .
D uring the spring and early sum m er of 19 11, sy s
tem atic w ork was inaugurated to determ ine the fertilizer resources of the U nited States. Sources of su p p ly for phosphoric and nitrogenous fertilizers were more or less w ell known. T h ere was no know n source of potash salts, how ever, of a n y econom ic im portance. I t is o b vio u sly desirable th a t such a source should be found and developed, and this fa ct was accen tu ated b y the controversies arising be
tw een the “ K a li S y n d ic a te ” an d certain A m erican im porters w hich received m uch notice in the current press and was the occasion of anim ated diplom atic exchanges betw een the G overnm ents of the parties to the controversy. T h e resources of the U nited S tates in possible sources of “ p o ta s h ” therefore received special atten tion , and various lines of in
q u iry were a c tiv e ly prosecuted. One of these, so far, has yielded p ositive results. (F or a com plete description of this w ork see Senate D ocum ent 190, S ixty-secon d Congress, 2nd session, en titled “ A P relim in ary R ep ort on" the F ertilizer R esources of the U nited S ta te s .” ) B alch ( T h i s J o u r n a l , i , 7 7 7
(1909) has called atten tion to th e gian t kelps of the California coast as occurring in enorm ous quan
tities and bein g especially rich in p otash salt. Sam ples of the kelp from Southern C alifornia and the salts derived therefrom were subm itted to this office b y Mr. B alch in Septem ber, 1910, and fu rth er data w ere secured from various sources.
E a rly in the summer, three field parties w ere or
ganized: Prof. George B. R igg observed and m apped the kelp beds or groves in ab out a h alf of P uget Sound; Prof. F ran k M. M cFarland su rveyed the groves from San Francisco B a y to P oin t Sur; and C aptain W . C. Crandall, of the L a Jolla S tation of the M arine B iological A ssociation of San Diego, su rveyed the groves of the m ain shore and outlyin g islands from P oint Lom a to P oin t Conception. Offi
cers of the B ureau of Fisheries m ade still further observations regarding the kelps of A laska.
In the w ork this sum m er som ething over one h un
dred square miles of kelp groves were surveyed, and there is reason to believe th a t the to ta l area on the Pacific Coast, from M agdalena B a y to Shum agin Islands, m ay possibly be 6 or 8 tim es this. Quite a large num ber of kelp and rockw eeds were found, although generally th e larger groves are a p p roxi
m ately “ pure sta n d s.” T w o of the kelps are chiefly of im portance as sources of potash. In th e northern groves the im portan t kelp is the Nereocystis luetkeana and in the southern groves it is the Macrocystis py- rifera. From P oin t Sur southw ard this la tte r occurs in large groves som etim es several square m iles in area, and often in v e ry dense masses.
N ereocystis grow s in alm ost a n y depth of w ater, w here there is a rock)’- bo tto m and also a strong tid e
w a y or otherwise continual m ovem ent of th e w ater.
M acrocystis grow s o n ly on exposed coasts where there is m uch m ovem ent of w ater, and p ractica lly alw ays a t depths of from 6-10 fathom s. A s the carbon dioxide and the oxygen necessary to the m etabolism of th e p lan t m ust b e obtained from the dissolved gases in th e w a ter a con tin u ally renewed mass of w a ter m ust be available. T h is fact, p rob a
b ly, accounts for th e difficulties encountered in t r y ing to artificially prop agate these algae under lab o ra to ry of aqu aria conditions. A ro ck y bottom is essential for the holdfasts w hich these p lan ts h ave in lieu of roots, and to anchor them .
N ereocystis is an annual. T h e fru itin g season is about over b y the m iddle of Ju ly, and in order to m aintain th e groves this algae should n ot be cu t before th a t tim e. M acrocystis, how ever, is p rob a
b ly r perennial; a t least, its life is m ore th an a cal
endar year, and if cu t ea rly in th e summer, it is said to be able to regain its lu xu rian t grow th in 40 days or th ereabout. A t least tw o cuttings, therefore, should be practicable. Its h ab it of grow th, m ore
over, th e spores form ing on fronds w ell below the surface, tends to p rovide against its extin ction or seri
ous depletion. N evertheless, it w ould p ro b ab ly be wise to m ain tain a “ closed season ” for this algae also aiid not perm it m ore than tw o cu ttin gs per sea
son, thus insuring a sufficient fru iting to m aintain the groves unim paired. Som e form of govern m ental p rotection or control of th e groves is obviously necessary to their m aintenance and efficiency.
T h e cu ttin g and harvesting of the kelp is a d e
tail of th e in d u stry w hich is in a far from satisfac
to ry shape. Several form s of cu tters h ave been suggested and a few tried. T h is is, how ever, a m e
chanical d etail w hich A m erican ingenu ity w ill u n qu estionably settle soon now th a t it has been shown to be w orth while. I t p ro b ab ly w il not be p racti
cable to cu t th e kelp more than 10 or 12 feet below the surface of the w ater, and in the case of th e M a
crocystis a t least a greater depth of cu ttin g should not be perm itted, in order to insure fru itin g and re
seeding of th e groves.
K e lp w as origin ally a term applied to the ashes of seaw eeds and rockw eed, b u t has becom e, es
p ecia lly in this cou n try, synonym ous w ith th e sea
w eeds or brow n floating algae, and on th e Pacific Coast is applied p op u larly to th e tw o p lan ts cited above. T hese p lan ts am ong other ch aracteristics h a ve this in com mon, th e y absorb re la tiv e ly large am ounts of potassium chloride from the sea w ater, m uch larger th an m ost other algae either of th e P a cific or other w aters. Dr. J. W . T urren tin e has m ade a large num ber of analyses. F rom his d ata it appears th a t N ereocystis contains ab out 30 per cent, of its d ry w eigh t of potassium chloride and M acrocystis n early as m uch. W ith both kelps, as th e y d ry out, large qu antities of potassium chlo
ride, m ixed w ith v a ry in g ' am ounts of other salts,
Feb., 1912 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . 77 effloresce on the surface, and can be rem oved read ily
b y sim p ly shaking. P ra ctica lly all th e potassium salts can be obtained b y lix iv ia tio n of the dried p lan t or of its ash.
N either N ereocystis nor M acrocystis of th e P a cific littoral contain as m uch iodine as m an y other seaweeds and rockweeds. N evertheless, the am ounts present are n otab le and co n trary to p opular belief;
the southern kelp contains m ore than does the northern.
A ccordin g to T u rren tin e’s analyses N ereocystis contains ab out 0.16 p er cent, and M acrocystis ab out tw ice as m uch. Besides iodine, other useful prod u cts can be obtained from these kelp, of which, how ever, space w ill n o t perm it a discussion here.
I t is n o t possible as y e t to g iv e an accu rate esti
m ate of the am ount of potassium chloride w hich the Pacific kelp groves can yield ann ually. W ith all conditions a t their best the m axim um possible yield m ight be in the neighborhood of 8 million tons, w orth a t present prices ab o u t 8300,000,000. No such yield is probable, how ever, a t least in the near future. T a k in g e very cons'deration, and leaning stron gly to conservatism it m ay be said th a t it ought to be p erfectly p racticab le to obtain an ann ual yield of a t least a m illion tons of potassium chloride, w orth a t present prices upw ards of $30,000,000. T h e iodine obtain able a t the sam e tim e should go far tow ard p a yin g the expenses of h arvestin g the kelp and ex tra ctin g th e potash.
I t has been assum ed in some quarters th a t b e
cause th e kelp can be m ade to yield ab o u t three tim es th e present to ta l potash im portations from G erm any th e latter w ill be stopped or g re a tly dim inished. T h is is v e ry m uch to be doubted. E x isting business engagem ents w ill ensure continued im portation for som e years to come. I t is possible, and g re a tly to be desired, th a t potash from A m erican kelp w ill reduce th e price of potash salts. B u t the va st b u lk of the potash salts goes into the South A tla n tic States because these states a t present are the great fertilizer consumers. In e v ita b ly the T ran s Mississippi States m ust soon use fertilizers and in fa ct th e m ovem ent has a lread y begun. A v e ry large increase in th e consum ption of fertilizers, and therefore of potash, m ay be an ticip ated w ith in the n e xt few years, enough p ro b ab ly to tak e up the A m erican production in sight and the im portation to be obtained from G erm an y as well.
The great im portance of the kelps lies not in the p rob ab ility of th eir exclu din g Germ an potash, b u t (1) if prop erly m anaged, in p reven tin g a m onopoly and regulating prices; (2) in m akin g possible a g re a tly extended use of fertilizers, and th ereb y perhaps even stim ulatin g im portations; and (3) in tim es of stress, giv in g the co u n try a resource and p reven tin g the agricu ltu ral interests from being a t th e m ercy of
a n outside power. F. K . Ca m e r o n.
S U R F A C E C O M BU STIO N .
In view of the w ide-spread p u b licity given to the lecture of Professor W . A . Bone, of Leeds, before the A m erican Gas In stitu te a t St. L ouis and the Chem- s its’ Club in N ew Y o rk , O ctober, and especially in view of the general accep tance b y gas engineers and chem ists in general of his process as a new discovery in com bustion, it seems h igh ly desirable to present a brief review of this art. Professor B o n e’s dem on
strations w ere all concerned w ith the burning of exp losive gaseous m ixtures continu ously b y m ethod w hich (quoting)
"co n sists e ssen tia lly in in jectin g , tliro u g h a su ita b le orifice a t a speed g rea te r th an th e v e lo c ity of b a c k firing, an e x p lo siv e m ix tu re of g as (or vap o r) a n d air in th eir co m b in in g p ro p o r
tion s in to a b ed of in can descen t, gran u lar re fra c to ry m a teria l, w h ich is disposed arou n d or in p ro x im ity to the b o d y to be h e a te d .”
T h is m ethod of burning explosive gaseous m ix
tures w as used b y C. E . L ucke, in 1900, or about eleven years ago. I t w as m ade the su b ject of a long series of experim ents, the results of w hich w ere p u b lished in a p ap er en titled “ T h e H eat E n gine P ro b le m ,” presented to th e A m erican S o ciety of Me
chanical Engineers, D ecem ber, 1901, and form ing p a rt of his D o cto r’s D issertation, from w hich the follow ing is quoted:
" T h e d e sira b ility of b ein g a b le to bu rn an ex p lo siv e m ix tu re co n tin u o u sly a n d n o n -e x p lo sive ly und er com m ercial ra th e r th an la b o r a to ry con dition s h a v in g been lo n g ob vio u s, a scries of e x p erim en ts w as u n d erta k en a t C olu m b ia U n iv e rs ity w ith th is end in v iew . M an y exp erim en ts w ere m ad e and various resu lts ob tain ed , b u t as a full a cc o u n t w ould ta k e to o m u ch sp ace and a v a il little , o n ly a few ch a ra cte ristic exp erim en ts w ill be n o ted as lead in g up to th e resu lt. C onsider a m ass of e x p lo siv e m ix tu re p assin g th ro u g h a n on -con d u ctin g tu b e w ith a u niform v e lo city , v. T h e n , if in flam m atio n be sta rte d a t som e p o in t, th e su rface o f com b u stio n m a y rem ain a t re st or m o v e w ith or a g a in st th e cu rren t. D en o te th e ra te of p ro p ag atio n b y r. T h e n , w h en v is g rea te r th an r the su rface of com b u stio n w ill m o ve w ith th e cu rren t, a n d if th e tu b e has an end, the flam e w ill ‘ b lo w o ff’ and com b u stio n cease; if v = r th e su rface of com b u stio n w ill rem ain a t rest, oth er in fluences b ein g in o p e ra tiv e; if v is less th a n r, th e su rface of com b u stio n w ill m o ve b a c k to w a rd th e source, or ‘ b a c k fla s h .’ ” " I n a p ra ctica b le sy ste m of b u rn in g an e x p lo siv e m ix tu re co n tin u o u sly, w e m a y s ta te th e fo llo w in g as d esid era ta and la te r see ho w th e y can be secured.
I. 'B a c k fla sh in g ’ m u st b e p reven ted . I I . 'B lo w o ff’ m u st b e p reven ted .
I I I . C om b u stio n su rface m u st b e localized.
I V . I t m u s t rem ain lo calized for w id e ran ges of feed or v e lo c ity of flow of the m ix tu re .
V . T h e lo ca liza tio n m u st b e u n a ffected b y changes of te m p era tu re.
V I . L a rg e or sm all q u a n tities m u st be b u rn ed w ith o u t a ffe c tin g th e a b o v e , and th e tran sition from v e r y sm all q u a n titie s to v e r y large, or vice versa, h o w ever sudden, sh ou ld be ea sy .
T h e first req u ire m e n t m ig h t be accom p lish ed in th ree w a y s:
(a) B y u sin g a lo n g tu b e o f som e c o n d u ctin g m a te ria l and so sm all in d ia m eter as t o p re v e n t th e passage of the flam e- ca p under a n y circum stan ces.
(b) B y u sin g w ire g a u ze screens.
78 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Feb., 1912
(c) B y cau sin g the m ix tu re to flow a t som e p o in t w ith a v e lo c ity a lw a y s greater th an the ra te of p ro p ag ation .
T h e - fir s t (a) is im p racticab le, as it perm its of o n ly sm all q u an tities b ein g burn ed; the second (6) w ill n o t w ork w hen th e w ire gauze g e ts h o t; th is leaves (c) w h ich is p r a c t ic a b le .”
‘ ‘ H ence w e m u st p u t dow n as th e first req u irem en t in our desired m eth od of com b ustio n th e follo w in g: A t some point before the combustion surface is reached the Telocity of feed must be such that v is greater than r.
R eq u irem en t I I m ig h t be accom p lish ed in three w a y s:
(a) B y so red u cin g the v e lo c ity a fte r p assing the h igh speed p oin t th a t w e h a v e a t som e su rface v — r.
(b) B y su d d en ly in creasin g th e te m p e ra tu re of th e m ix tu re so as to increase the ra te of p ro p ag ation w h ile v rem ain s con sta n t; or
(c) B y red u cin g v, b y sp read in g the curren t, and in creasin g r b y heatin g. A ll of th ese w a y s are p ra ctica b le ; b u t, as a r e du ction of v e lo c ity alon e or a su fficien t h e a tin g alon e w ould n o t p ro du ce th e desired resu lts so w ell as b o th o p e ra tin g t o geth er, th ere w a s in tro d u ced as the second req u irem en t in our desired m eth od , the follo w in g: A fter passing the point where v is greater than r, the velocity of the m ixture should be so reduced and its temperature increased as to make v1 — r l. ”
“ M a n y w a y s of b rin g in g a b o u t the a b o v e w ere tried , b u t o n ly one seem ed p reem in en tly good b y reason of its sim p licity and effectiven ess, for it . fulfils m o st p e rfe c tly th e requ irem en ts proposed for our desired m eth o d ; th is is, to fill a cone w ith frag m en ts of re fra c to ry m aterial such as p o tte ry , brok en c ru cibles, b its of m agn esite, or a n y other ro ck t h a t w ill stan d the high te m p e ra tu re w ith o u t fusing. In con es of 60 degrees, a n d w ith a ‘/.-in ch orifice, I h a v e ound p ieces of a b o u t */, in ch dia m eter to answ er w ell. T h ese sep a ra te pieces of solid m a tte r in terp ose m a n y reflectin g su rfaces w ith o u t m a te ria lly h in derin g th e a d v a n ce of th e m ix tu re , and cause i t to sp read in th e w a y desired, k eep in g th e su rface of com b u stio n sp h erical and p re v en tin g diffusion. A v a ria tio n of v e lo c ity causes the sp h erical su rface of com b u stio n to v a r y o n ly in d iam eter, and the lim its of feed are determ ined o n ly b y th e size of th e c o n e ."
“ A cone of g iv e n a ltitu d e w ill g iv e th e g re a te st ran ge of v aria tio n of d ia m eter of cross section w hen its a n g le is 180 degrees. T h is is a p lan e su rface w h ich , w ith the orifice and broken ro ck should ap p ear as in F ig. . (F ig . 49, p a g e 58, ‘ T h e H e a t E n gin e P ro b lem ’). H ere che su rface of com b u stio n is a p p ro x i
m a te ly a sem i-sphere. T ria l sh ow s t h a t th is a rra n g em en t
is fu rth er augmented by reason of the increase of the rate of propa
gation caused by the passage of the m ixture between the hot frag
ments. H ence b o th prin ciples o p era te sim u ltan eo u sly to w a rd the desired e n d .”
“ W e h a v e th u s a rriv ed a t a m eth od of co n tin u o u sly b u rn in g ex p lo siv e m ix tu re s of a ll sorts, w h eth e r in th e chem ical p ro p ortion or n o t .”
“ W h en a chem ical p ro p ortion is m a in tain ed in th e m ix tu re , all th e com b ustio n ta k e s p la ce on th e com b u stio n su rface, g iv in g a b so lu te ly n eu tral p ro d u cts of com b ustion , b u t w hen an excess of gas is p re sen t w ith in certain lim its, all g a s t h a t can find o x y g e n bu rn s e x p lo siv e ly betw een th e solids, w h ile th e excess a cts m e re ly as a n eu tral d ilu e n t to be b u rn ed w h en it m eets a n o x y g e n atm o sp h ere la ter on. B y p ro p erly p la cin g the o x y g e n atm o sp h ere to bu rn the excess gas, w e can g e t the h o t p ro d u cts eith er red u cin g or o x id izin g — re d u cin g a fte r le a v in g th e e x p lo siv e com b u stio n su rface and before m e e tin g th e excess of o x y g e n in the atm osp h ere, o x id izin g a fte r th a t m e e tin g .”
T his quotation is reproduced, togeth er w ith other sim ilar m atter b y H utton in his book “ T h e Gas E n g in e ,” 1903, pages 486-493. I t cannot, therefore, b e said th a t the scientific and technical w orld has not had op p o rtu n ity enough to becom e acq u ain ted
w ith this w ork, done som e eleven years ago and in p rin t for ten years, especially as m an y journals quoted portions of the A . S. M. E . paper, m entioned above, as w ell as quotations from another paper b y the sam e author, presented to th e A . S. M. E ., M ay, 1902, on 1;he ap plication of th e sam e process to the burning of oils.
N o t o n ly does it appear from the ab o ve th a t L u ck e p racticed this process for both gases and oils prior to T9oi, b u t tw o p aten ts were issued to him for the process. U . S. No. 755,376 and No. 755,377, filed resp ectively June 7, 1901, and J u ly 30, 1901, both issuing M arch 22, 1904, contain illustration s and descriptions of app aratus su b stan tially the sam e as used b y Bone, b u t the claim s cover th e method b ro a d ly and are not confined to the app aratus shown.
T o m ake clear the com parison, consider Figs. 3 and 4, w hich are reproductions of the p a te n t illustrations,
F ig . l . F ie . 2.
w o rk s p e rfec tly , and th e lim its of feed are d eterm in ed o n ly b y th e size of th e pile of ro ck su rrou nd in g th e opening. A cone of 360 degrees, or 110 cone a t all su g g est th e surroundin g of th e n ozzle b y broken ro ck w ith o u t a n y enclosin g w a lls F ig 2 (F ig . 50, p age 5S, 'T h e H e a t E n gin e P ro b le m ’). T h is a rra n g em en t also w o rk s re m a rk a b ly w ell. T h e su rface of com b ustion is here a p p ro x im a te ly a sphere g iv in g th e g rea te st possible increase in area of th e su rface of com b u stio n for th e d ista n ce tra v ele d from th e n o z z le .”
“ N o t o n ly is the g rea te st possible ran ge of actio n b y v e lo c ity re d u ctio n th u s ob tained , en a b lin g th e g re a te st possib le a m o u n t o f m ix tu re to be b u rn ed in a g iv e n volum e, b u t th is a m o u n t
Feb., 1912 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . 79
sta n tia lly th e sam e d ista n ce from th e p la ce w h ere th e sp read in g begins, th ere b y re d u cin g th e v e lo c ity of th e m ix tu re to th e ra te of p ro p ag atio n of in flam m atio n a n d p re
v e n tin g diffusion w ith o th er g a s; and b u rn in g w ith in th e b ed so m u ch of th e fuel as herein form s w ith th e sup p lied o x y g e n an e x p lo siv e gaseou s m ix tu re and b u rn in g a t or b e y o n d th e su rface of th e bed th e rem ain d er of th e fuel, su b s ta n tia lly as d e s crib e d .”
I t w ould appear th at these tw o claim s of the m ethod of burning explosive m ixtures w h eth er in chem i
c a lly com bining proportions or not, as used b y Bone, are b road ly covered and allowed.
I t is of interest in this connection to quote the U. S. P a te n t Office citation s w hich w ere overcom e in connection w ith the L u ck e cases, and these are:
i , V erstraet, Jan. 12, 1869; 2, Sm ith, No. 170,198, N ov. 23, 1875; 3. Paquelin, No. 180,155, J u ly 25>
1876; 4, W eeks, O ct. 12, 1880; 5, H ubbard, No.
260,983, J u ly 11, 1882; 6, W ainw right, Oct. 12, 1886;
7, G rant, No. 457,081, A ug. 4, 1891; 8, Rogers, March
F ig . 4.
general though only the first claim in each case is quoted, there being three claim s for the first p a te n t and five for the second.
C l a i m i , U . S . P a t e n t No. 755,376 t o L u c r e .
“ T h e m e th o d of b u rn in g e x p lo siv e gaseous m ix tu re s w h ich con sists in cau sin g the m ix tu re to m o ve w ith a v e lo c ity greater th an th e ra te of p ro p ag atio n of in flam m atio n th rough th e m ix ture, and th en re d u cin g th e v e lo c ity to th e ra te of p ro p ag ation of th e in flam rhation and p re v e n tin g diffusion w ith o th er gas, b y cau sin g th e m ix tu re to spread o u t so t h a t the su ccessive su r
faces of u niform v e lo c ity sh all h a v e a d ja c e n t p oin ts in a n y su ch su rface a t su b s ta n tia lly th e sam e d istan ce from th e p lace w h ere sp read in g b egin s, and b u rn in g th e m ix tu re a t th e su r
face a t w h ich th e v e lo c ity is eq u al to th e ra te of p ro p ag ation of in flam m atio n , su b s ta n tia lly as d e scrib e d .”
C l a i m i , U . S. P a t e n t N o . 7 5 5 ,3 7 7 t o L u c k e .
“ T h e m eth od of b u rn in g fluid fuel w h ich con sists in cau sin g the fuel and a su ita b le com b u stio n -su p p ortin g g a s in p ro p or
tio n s su ch th a t th ere w ill b e an excess of fuel o v e r th e q u a n tity requ ired for p e rfect ch em ical com b in atio n w ith th e o x y g e n of th e su p p ortin g-gas to flow in to a h o t com b ustion-bed, the su p p ortin g -g as m o v in g w ith su ch v e lo c ity as to cau se th e re su ltin g m ix tu re to m o v e w ith a v e lo c ity g rea te r th an th e ra te of p ro p ag ation of in flam m atio n th ro u g h th e m ix tu re , a n d th e com b ustion-b ed b ein g of su ch a n atu re as to cau se th e m ix tu re to spread o u t so th a t th e su ccessive su rface of uniform v e lo c ity sh all h a v e a d ja c e n t p oin ts in a n y su ch su rface a t su b
PH Y SIC A L-IN D T T3T R IA L C H E M IS T R Y .
A t first sight it seems as though the tw o divisions of organic ch em istry and inorganic ch em istry covered th e whole field and as though a m an who w as well posted in these subjects w ould h ave all the know ledge of pure ch em istry needed b y one going into industrial ch em istry. T h is is not tru e because th e organic chem ist and the inorganic chem ist of the colleges w ith Fig. 5, reproduced from the Am erican Gas
Light Journal, illustrating B o n e’s A p p aratu s (Dec.
4 , 19 11). T h e follow ing quotations of the p aten t claim s w ill show the scope of these tw o p aten ts in
F ig . s .
22, 1892; 9, Archer, Feb. 28, 1893; 10, Ladd, No.
550,831, Dec. 3, 1895; 11, B arker, No. 577.638» Feb.
23, 1897; 12, Burrow s & W eaver, No. 672,888, A p ril 30, 1901; M usker & H ay, No. 676,096, June n , 1901.
D etailed exam ination of the Bone paper reveals on ly one stru ctu re or app aratus n ot used or specifi
ca lly described b y L ucke, and th a t is the porous diaphragm in place of the broken refracto ry m aterial.
T here appears to be. how ever, no essential difference betw een a porous diaphragm and a b o d y of broken m aterial excep t in th e shape or size of the passage
w a y s open to th e flow of the gaseous m ixtures.
In view of these experim ents, the w ide-spread and a p p a ren tly general acceptance of th e supposition th a t B o n e’s w o rk is new seems difficult to support.
A p p aren tly, the o n ly journal th a t has n o t fallen into this error is "P o w e r " w hich in its issue of N ov.
21, 19 11, calls atten tion to th e sim ilarity of L u c k e ’s and B o n e’s processes, editorially.
8o T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Feb., 1912 are interested p rim arily in the nature of the final
product, w hile the technical m an is m uch more con
cerned w ith efficiency in its bearing on cost of pro
duction. Consequently it is being recognized more c learly e v e ry year th a t a thorough grounding in or
ganic and inorganic ch em istry is m erely a prelim i
n a ry stage in the training of an industrial chem ist and th a t his chem ical course is incom plete unless it leads up to and includes physical chemistry, which m eans the common-sense stu d y of m ethods. Some fifteen years ago I announced at one of the m eetings of the A m erican Chem ical S o ciety th a t a proper trainin g in physical chem istry w as the best possible train ing for a m an going into technical work. Ai;
th e tim e th e statem ent was considered as the un
fortu n ate outburst of a m isguided and unbridled
SO M E P R O B L E M S IN C H E M IC A L E N G IN E E R IN G P R A C T I C E .1
M A N U F A C T U R E A N D T E S T IN G O F SH IP P IN G C Y L IN D E R S F O R A N H Y D R O U S A M M O N IA .
B y F . W . Fr e r i c i i s- R e c e i v e d J a n u a r y 5 . 1 9 1 2 .
IN T R O D U C T IO N .
E ncouraged b y some of m y friends, I offer to-d ay w h at m ay be called a continuation of the address w hich I delivered in Chicago, six m onths ago, and w hich has been alread y published in the O ctober and N ovem ber (1 9 1 1 ) issues of T h i s J o u r n a l .
F o r to-day, I have selected three problem s in chem i
cal engineering practice, the characters of which are w id ely different from the previous problem s and w hich give additional proof of the sta te m ent th a t the field of chem ical engineering is ex ceedingly varied and difficult to define. A gain , these problem s are selected w ith a view of giving, to the student of chem ical engineering, an idea of the v a rie ty of questions w ith w hich he m ay be con
fronted but, a t the sam e tim e, th e y are chosen to call atten tion to the w ide difference betw een scien
tific chem ical research and the investigation of chem i
cal engineering problems.
Scientific research treats p rin cip ally w ith re
actions w hich produce definite substances and can be follow ed up b y chem ical formulae.
Chem ical engineering problem s a r e ' based on re
actions also b u t th e y include cost, qu ality, yield, lab or and safe ty of those engaged in th e m anufacture of goods, and provide for the convenience in handling th e goods b y the consumer. In the m anufacture of chloroform from bleaching-pow der and eth yl alco
hol, th e process was known, b u t the ob ject of the research w as to find the conditions under w hich the m axim um yield could be obtained b y a know n reac
tion and to construct apparatus w hich w ould give these conditions w ith greatest econom y. In the
1 A d d ress re a d a t th e A n n u a l M eeting of th e A m erican I n s titu te of C hem ic a l E n g in eers, in W ash in g to n , D . C., D ecem b er 20, 1911.
im agination. T o -d a y it is such a truism th a t it is out of place anyw here excep t in an editorial.
This is the more interesting because th e real de
velopm ent has scarcely begun. W ith in the n e x t three or four years w e shall g e t colloid chem istry on a sound scientific basis, and when th a t tim e comes the field of the p h ysical chem ist w ill include: ph o
tog rap h y; tan n in g; brew in g; rubber; d yein g; soap;
tex tiles; artificial silk and other filam ents; cellulose;
paper; celluloid and other p la s tic s; starch ; glues and cem en ts; paints, lacquers and va rn ish e s; lub ricatin g oils and greases; clay, fu ller’s earth and p u tty ; inks; cer
am ics ; glass and en am els; m ilk, b u tte r and casein e; cook
ing; w a ter purification and sewage disposal; food pre
se rvatives; slags; soils; physiology, b io lo gy and m edi
cine. W i l d e r D. B a n c r o f t .
construction of lab orato ry apparatus referred to, the savin g of tim e effected b y the im proved appa
ratus w as the leading elem ent. In the m anufac
ture and testin g of shipping cylinders for liquefied am m onia gas, the sa fe ty of handling and the con
venience to th e consum er was the o bject of in vesti
gation.
These, togeth er w ith the three problem s treated, g ive on ly a few form s of the great v a rie ty of dem ands w hich are lik ely to be m ade on the chem i
cal engineer, and I should feel h igh ly gratified if I h ave given an incentive to others of our members to follow in th is direption, b y givin g th e solution of additional cases, so th a t we m ay obtain a large v a riety of solved problem s b y which the students in our profession m ay be guided in their work.
m a n u f a c t u r e a n d t e s t i n g o f s h i p p i n g c y l i n d e r s
f o r a n h y d r o u s a m m o n i a.
A ll chem ical m anufacturers produce goods and these goods need packages in order to be m arketed.
T h e question of p ackages is often more difficult and requires m ore stu d y and cap ital t h a n . th e m anu
factu re of th e goods to be shipped in them and this is p a rticu larly the case if the packages are intended for com pressed or liquefied gases, which can only be handled w ith reasonable sa fe ty if the containers in w hich th e gases are confined are constructed and k e p t in such a manner, th a t danger in handling them as far as p racticable is excluded.
I t is often said th a t the m anufacture of packages is n o t a chem ical problem , and chem ists should not m eddle w ith questions outside of their line; th a t if questions of packages arise th e y should go to men who m ake them and ta k e their advice. B u t there are instances in w hich the chem ical engineer is con
fronted w ith the necessity of going him self into the m anufacture of containers, and in such cases the m anufacture of packages becom es a chem ical engi
neering problem . I experienced a case of th a t kind not long ago when I needed a large num ber of va lves for am m onia shipping cylinders, and since the ob ject
ORIGINAL PAPŁRS
Feb., iQ 1 2 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . 81 in volved m an y' thousands of dollars I w ent to the
trouble of stu d yin g the question thoroughly.
I m ade designs and had models m ade a t great expense, som e of w hich yo u see am ong the exhibits.
W hen I had arrived a t a m odel w hich seemed to fill m y requirem ents, represented b y Fig. i, I selected a shop where sim ilar w ork had been done and contracted a t their price for 1,500 valves, equal to m odel subm itted. W hen deliveries w ere begun I had to reject e v e ry va lve. W hen the defects were p ointed out it w as adm itted th a t the differ
ences were there, b u t it was contended th a t the valves delivered were ju s t as good and answered the pur
pose. T o this I too k exception. A s the proprie
tors of the shop w ere desirous of fulfilling th eir con
tract, I w en t into th eir shop to help things along, and investigated the cause of the u n satisfactory w ork w hich had been delivered.
F ig . 1.— o, 2 p ip e c o n n e c tio n ; b, 3/s * p ip e co n n ectio n : c, plug: d, iron w a sh e r; e, ru b b e r w a sh e r; f , v a lv e s te m ; g, stu flin g b o x n u t o r g la n d ; h, a n d hl, iro n w a sh e rs; i , p a c k
in g ; j , s o ft m e ta l s e a t; k , p ip e c o n n e c tio n fo r d ip p e r p ipe.
T h e drop forgings for th e v a lv e bodies were m ade b y a reliable firm on m y direct order. There was no trouble on th is accoun t and the v a lv e stem s and the nuts were m ade from standard steel bars, so th a t there could n o t be a n y fau lt w ith the m aterial.
In the shop I found some good and some worn m achine tools, and there w ere some good m achinists, b u t the m ajo rity of help w ere second-class men.
Since w ork w as continuously com ing in it w as neces
sa ry to sh ift m y w ork from one place to another to keep the shop going, and the result was unsatisfac
to ry work.
T he v a lv e stem s and lock nuts had been sublet to another shop of good reputation a t a con tract price, b u t th ey were turned out on a m uch used screw m achine, were therefore not accu rately m ade, and w ere n o t sa tisfa cto ry to me.
F or m aking good valves, perfect tools and good m echanics seemed to be necessary, and in order to turn them out a t the rate of about 200 va lve s per week, b y m y calculation, a sum of ab out $3,000 was
to be invested in tools. T h e shop was unw illing to m ake such an investm ent. N either could th ey prom ise to p u t only first-class m achinists on the w ork, unless I w ould agree to p a y a price w hich was pro
hibitive.
In this m anner, I was forced to undertake the w ork m yself. I bou gh t the best m achine tools I could obtain, and arranged a shop containing tw o screw m achines, tw o lathes, tw o drill presses, and one gas furnace for case-hardening. Furtherm ore, one pow er h ack saw and em ery wheel, all of which cost ab out $3,000. I em ployed three good m achin- sits and tw o helpers, p u t one of m y engineers in charge of the shop and turned out 180 good va lve s per w eek a t a cost w hich w as m uch less than th e price, w hich I had paid to th e outside shop for u n satisfactory work.
Compressed and liquefied gases are m anufactured in^'very large quantities, and for their safe transportation b y com m on carriers, rules h ave been adopted in m an y coun
tries for constructing and testing con
tainers in w hich th e y m ay be accepted for shipm ent b y transportation com panies.
Containers used for this purpose generally h ave th e form of cylinders.
One set of rules has been agreed upon b y the railroads of G erm any, A u stria H ungary, Belgium , France, Denm ark, Ita ly , L uxem bourg, T h e N etherlands, R oum ania, Russia, Sweden, and S w itzer
land, w hich rules are com m only referred to as the In tern ation al R ules for E u ro pean countries. Up to recent tim es there were, however, no regulations of this kin d in the U nited S tates b u t the A m erican R ailroad A ssociation, , in con
junction w ith com m ittees appointed b y m anufacturers of com pressed gases, h ave been w orking on such rules for several years, and these rules were recen tly adopted b y the In terstate Com m erce Commission of the U nited States, and w ent into effect, O ctober 1, 1911.
T h e general rules, ap p lyin g now to shipping con
tainers for com pressed and liquefied gases, are as follow s:
“ (a) Gases th a t m ay com bine chem ically m ust not be shipped in one cylinder. Cylinders purchased hereafter for the shipm ent of com pressed gases m ust be m ade in accordance w ith specifications approved b y the In terstate Com m erce Commission.
"(b) B y w ater jack et, or other suitable tests, each cylin der used for shipping liquefied gases m ust be subjected a t least once in five years to a uniform interior pressure not less than one and one-quarter tim es the interior pressure th a t w ould result from heatin g the cylin der uniform ly, in its m axim um charged condition, to a tem perature of 130° F . E ach cylin der used for shipping under pressure not exceeding 1,000 pounds per square inch nonliquefied gases or gases in solution, m ust be subjected at least
82 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Feb., 1912 once in five years to a uniform interior pressure not
less than tw ice the charging pressure for such cylinder, corresponding to a tem perature of 700 F . ; when the ch arging pressure exceeds 1,000 pounds per square inch, the test pressure m ust not be less than one and one-half tim es the charging pressure. A cylinder m ust be condem ned when it leaks, w hen the per
m anent expansion is due to local weakness, or when it is uniform and exceeds 5 per cent, of the total expansion. W hen the charging pressure is less than 300 pounds per square inch it will not be necessary to m easure the perm anent expansion in quintennial pressure tests, provided the cylin der in question has p reviou sly passed this test.
“ (c) T h e w eight of gas charged into an y cylin der m ust n o t a t a tem perature of 130° F . cause an in
terior pressure in excess of three-fourths of the elas
tic lim it of th e w eakest p art of the cylinder.
“ (d) T h e m anufacturer m ust not offer for trans
portation a cylinder filled w ith such charging den
s ity of a n y gas as w ould produce failure in the test prescribed for th a t gas.
“ (e) A fte r D ecem ber 31, 1914, all cylinders m ust p lain ly be stam ped w ith th e date of last test— for exam ple, ‘ 4—09' for April, 1909— or otherw ise dura
b ly m arked to show com pliance w ith this rule; and
inspected sep arately for defects inside and outside and then subjected to the follow ing tests:
(a) T o each crop end cu t from th e pipe from which the cylinders are to be m ade, a flatten ing test m ust be applied w ith the w eld 4 5° aw ay from the side w hich is su bject to the greatest bending stress, w ith k nife edges of w edge shape converging a t an angle of 60°, th e point being rounded off w ith a radius of one-half inch. In this test, the crushing of the w alls m ust be to w ithin four tim es the thickness of the m etal, and a crop end m ust w ith stand the te st w ith ou t cracking.
(b) A n internal h yd ro static test of 600 pounds per square inch m ust be applied to each length of pipe under w hich it m ust n ot show signs of leaking a t the w eld or elsewhere.
4. E ach finished cylin der m ust be tested b y in
ternal h yd ro static pressure as specified in above table, paragraph 1, the test to be conducted as fol
lows:
(a) A fte r filling cylin der w ith w ater, the test pres
sure specified m ust be applied for the purpose of detecting leaks and rounding up the cylinder.
(b) T h e cylinder, if tigh t, m ust be placed in a w ater ja c k e t or other approved apparatus for m eas
uring the expansion, and the test pressure again T U R N A C E .
b y D ecem ber 31, 1911, not less than one-fourth of the cylinders in use for shipping purposes m ust be th us tested and m arked.
“ (/) Cylinders containing acetylen e gas m ust be m ade of tough steel and m ust be com pletely filled w ith a porous m aterial th a t has been tested b y the B ureau of E xp losives and approved b y the In ter
state Com merce Commision, and this m aterial m ust be charged w ith acetone or its equivalen t not to e x ceed 40 per cent, of the interior volum e c a p a city of the cylinder. T h e pressure in cylinders containing acetylen e gas m ust not exceed 250 pounds per square inch a t a tem perature of 70 0 F . ”
In addition to these general rules, specifications for shipping containers are adopted, each set of speci
fications being different for different gases.
1. The specifications for lap-welded cylinders intended for shipping anhydrous am m onia are shown in T able I.
2. Cylinders m ust be m anufactured from lap- welded pipe m ade of soft steel of th e best w elding qu ality, free from blisters, cracks, or other injurious defects.
I N S P E C T I O N A N D T E S T I N G O F M A T E R I A L .
3. T h e pipe intended for these cylinders m ust b e m anufactured b y th e best appliances and accord
ing to the best m odem practice, each length to be
applied. T h e perm anent expansion under this test m ust not exceed 10 per cent, of the w hole volum etric expansion a t the pressure specified.
G E N E R A L C O N S T R U C T I O N A N D I N S P E C T I O N .
5. T h e m anufacture of the cylinders m ust be com pleted w ith the b est appliances and according to the best m odem m ethods. A ll finished cylin ders m ust show a reasonably sm ooth surface, and m ust h ave passed the above inspection and tests w ith ou t show ing a n y defect in w orkm anship or m aterial lik ely to result in a n y appreciable weakness in the finished cylinder. E a ch com pleted cylin der m ust be inspected for such defects a t th e m ill b y th e pur
chaser or his representatives before acceptance.
These rules and specifications are the results of exten sive tests m ade w ith cylinders taken from the present equipm ent of the various m an ufacturers and w ith new cylin ders m ade for the specific p u r
pose of testing.
I am much pleased to sa y right here th a t tests h ave shown the shipping cylinders of old equipm ent generally to be of greater strengths than required b y the regulations, from w hich fa ct it m ay b e con
cluded th a t m anufacturers alw ays h ave been anxious to m ake shipping cylinders of am ple strengths so th a t accidents m ight be prevented.
Feb., 1912 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . 83
Ta b l e X.— Sh i p p i n g Co n t a i n e r Sp e c i f i c a t i o n N o . 4.— (See p a r. 1822(a), p. 41.) L ap w cld cd S teel C y linders fo r A n h y d ro u s A m m onia.
R ev ise d J a n u a r y 1, 1912. E ffe ctiv e M arch 31, 1912.
T a b le of D e tails a s to D im ensions.
O u tsid e O ver-all N om inal T e st H e ad . M outh. W eig h t of cy lin d er.
d ia m e te r le n g th of th ick n ess p ressu re
of cylin d er. o f c y lin d e r p e r sq u are Low H ig h D ia m Low H ig h Low H ig h
c y lin d e r. --- ---* w all. inch. D e p th . lim it. lim it. e ter. lim it. lim it. lim it. lim it.
In ch es. F t . in. In c h . P o u n d s. In ch es. • Inches. In c h e s. In ch es. In ch es. In ch es. P o u n d s. P o u n d s.
10 3 10 0 .1 9 1000 3V4 3 V lC 3>»/i, 7V2 7Vs 7 V s 87 112
10 4 0 0 .1 9 1000 3V4 3 % o 3 lß/lö 7>/s 7V« 75/s 90 115
10 7 0 0 .1 9 1000 33/4 3V ,„ 3 'V .o 71/ 2 73/ s 7V s 150 175
10 3 10 0 .2 7 1500 33/4 39/ 10 3 'V ia 7 V j 7V8 7V„ 113 141
10 4 0 0 .2 7 1500 33/4 3 V , 0 3>V10 7>A 7V s 7Vs 117 145
10 7 0 0 .2 7 1500 33/4 3°/10 3 'V i . 71/ 2 7Vs 7Va 203 237
12 7 0 0.21 1000 33/4 3V .0 3 « / » 9 9 9 '/ . 220 250
B y these regulations, containers for liquefied gases m ust be safe a t pressures to w hich the fu lly charged cylinders w ill be exposed a t 130° F. and the follow ing tab le gives the pressures corresponding to various tem peratures for some liquefied gases m ost com m on ly handled.
Ta b l e I I .
T e s t p re s su re , a b so lu te .
A b so lu te p re s s u re a t
15 ° C . 38 0 C.55 0 C. ru le s. , I n te r-
n a tio n a l C ritic a l A m e r- a n d G er- p re s s u re ic a n m a n ru le s, a b so lu te . 5 9 ° F . 100° F . 130° F . L b s. L b s. A tm . L b s. A tm . C a rb o n d io x id e 768 1160 1227 2454 2793 190 1132 77 N itro u s o x id e . 732 1112 1180 2360 2646 180 1103 75
A m m o n ia 104 215 340 425 441 30 1690 115
C h lo rin e . 85
S u lp h u r d io x id e 40
156 250
147 312 184
323 176
22 12
1374 1160
C ritical te m p e r
a tu re .
°C. °F . 3 1 .1 88 3 5 .4 96 1 3 0 .0 266 9 3 .5 1 4 5 .4 294 7 8 .9 1 5 5 .4 312
From this tab le it is seen th a t the pressures v a ry g re a tly w ith the different gases and, consequently, shipping cylinders used for different gases m ust be of different strengths.
From the tab le it is also evid en t th at, in a general w ay, th e In ternational and A m erican R ules agree fa irly well, and w e w ill now have to see in w hich w a y the shipping cylin ders m ust be constructed in order to com ply a t the sam e tim e w ith the rules of the R ailroad Com panies w hich are considered
b y them necessary to secure safe h and
lin g; w ith the interests of the mills, w hich require th a t the specifications be inside of the p ossib ility of m anufacture a t a m ini
m um cost; and w ith the interests of m anufacturers and consum ers of the goods, w hich m ake it desirable th a t the shipping cylinders be as ligh t as possible in order to facilita te the handling ■and securing the low est freights.
In designing shipping cylinders, the first question is: which m etal can be used and w h at m ust be the strength and thickness of the m aterial of the con tain er to w ith stand the pressure to w hich the cylinder will be subjected?
T h e answ er to this question is found b y the follow ing considerations:
M aterials used for construction of ship
ping cylinders m ust be indifferent to the gases, w hich are to be shipped in them .
A ll m aterials h ave constan t proper
ties, am ong them , d u ctility, th e tensile or b reaking strength and elastic lim it.
A bar of an y m aterial, h avin g a cross section of one square inch, subjected to
a m oderate strain, , w ill elongate and spring b a ck to its initial length when the strain is released.
T h is indicates the elastic ity of the m aterial. If, in repeating th e experim ent, the strain is increased, a point w ill be reached a t which the b ar does not spring b a ck to its original length, and the strain at w hich this takes place is the elastic lim it of the m aterial. I f the strain is increased beyond the elastic lim it, th e b a r w ill be disrupted and the strain at w hich disruption takes place is the breaking strain of the m aterial.
T h e toughness or d u c tility of a m aterial is tested b y bending a strip of it, and looking for cracks on the bend. It is accepted th a t a cylin der m ade of m aterial w hich com plies w ith this bending test w ill not break up into flying fragm ents if it explodes b y influence of internal gas pressure.
From the values of the breaking strain and the elastic lim it of m aterials, the dimensions of shipping cylinders m ay be com puted.
In a cylinder, filled w ith com pressed gas, the strain is tw ofold, nam ely, in the direction of the longitudinal axis of the cylin der and a t right angles to this direction.
G iven a cylin der of ten inches diam eter, filled w ith
F ie . 3.
84 T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Feb., 1912 gas under 100 pounds pressure to the square inch,
the to ta l pressure on each of the circular ends is equal to the area of a ten-inch circular plane, e x pressed in square inches, m ultiplied b y 100 pounds, w hich is equal to 7 5 ^ 4 pounds. Since this stress m ust be taken up b y the sides of the cylin der in the circum ferencial seam, betw een the bo tto m of the cylinder -and its sides, each inch of the circum fer-
a t th e present tim e. T h e highest grade steel has a breaking strength of from 65,000 to 150,000 pounds, w ith an elastic lim it of 40,000 to 110,000 pounds.
T h e chem ical analysis of a sam ple of steel, h avin g 50,000 pounds elastic lim it, w as carbon 0.55% , phosphorus 0.05% , sulphur 0.04%, b u t this steel does not w eld and can be used only for th e m anu
facture of seamless tubes.
A n inferior grade of pipe steel now com m only used has a breaking strength of 50,000 to 55,000 pounds, w ith an elastic lim it of about 30,000 pounds. T w o analyses of this kind of steel h ave given the
following; results:
s . P . Mn. v C.
P e r c cn t. P e r cen t. P e r c en t. P e r c e n t.
I 0.0 6 1 0 .0 9 5 5 0 .2 0 .0 8
I I 0 .0 6 8 0 .1 2 1 0 .4 2 0 .0 8
F ie . 4.
ence (which measures 31.4 inches) m ust w ithstand a stress of 7584 divided b y 31.4, equal to 241 pounds.
T h e stress in the m aterial at right angles to this direction is equal to the charging pressure on a plane w hich is placed through the longitudinal axis and confined b y the sides of the cylinder.
A ssum ing again the charging pressure to be 100 pounds per square inch, then the strain on tw o op
posite sections in the sides of th e cylinder, each sec
tion one inch long and of the thickness of the m a
terial, is equal to the sam e pressure of 100 pounds on a plane of one inch w id th and in length equal to the diam eter of th e cylinder. T h is is in our case
100 tim es 10, equals xooo pounds.
O ne-half of this stress is taken up on each of the ends of the plane or w h a t is the sam e in each line of th e cylin drical p a rt of the container w hich is par
allel to th e a xis of the cylin der and one inch long, w hich in our case is 500 pounds. T h is stress, being greater than the stress in the direction of th e axis, it m ust govern in the calculation of the cylinder.
I f the cylin der is m ade of steel and assum ing the tensile strength of the m aterial to be 50,000 pounds to th e square inch, w ith an elastic lim it of 30,000 pounds, then the tu b u lar p art of th e cylin d e r m ust h a ve a thickness, expressed in inches, equal to 500, d ivided b y 39,000, or '/«o of an inch, in order to w ith stan d an interior pressure of roo pounds to the square inch and strain ing th e sides n o t beyond th e elastic lim it of the m aterial. F or th e heads, the required thickness of th e m aterial is th e sam e as fo r the sides, if the heads h a ve the form of a co n vex hemisphere. If th e heads are flat or concave, the thickness is n o t easily figured, since it depends upon the form of the head and the bending strength of th e m aterial, which in the same m aterial is subjected to considerable variation .
T here are tw o kinds of pipe steel m anufactured
This steel can be w elded, can be bent over to four tim es its thickness w ith ou t cracking in th e bend, and furnishes a t present the m aterial for w elded tubes and cylinders.
, JU p to ab o u t fifteen years ago m anganese w as not com m only used as an ingredient for pipe steel, and an increased am ount of phosphorus w as a t th a t tim e left in the steel to g ive it w elding qualities.
Such steel has a low breaking strength of ab out 40,000 to 45,000 pounds, w ith a com parative high elastic lim it of ab out 30,000 pounds. T w o analyses of this steel have given the follow ing results:
s . P e r c en t.
I 0.0 3 1 I I 0 .0 3 2
P . P e r cen t.
0 .2 9 2 0 .2 9 3
M n.
T rac e T rac e
T his steel does w eld b u t breaks on bending, for w hich reason its m anufacture w as abandoned.
If th e necessary strengths of shipping cylinders for th e various gases are figured from th e values g iven in T ab le II, it w ill be found th a t carbonic acid, nitrous oxide and oxygen (under 1,500 pounds pres
sure) require cylinders m ade of steel of high tensile strength, w hile cvlinders for am m onia and com pressed air (\xnder 600 pounds pressure) for railroad cars and for m an y other gases, can be m ade from steel of less strength.
B earin g in m ind th a t steel of high tensile strength cannot b e welded, w hile steel of less strength has w elding qualities, the m an ufacture of steel cylin ders in this co u n try is carried o u t in tw o different w ays.
C ylinders m ade from high-grade steel are m ade b y the seam less m ethod.
T h is class of cylinders is represented b y carbonic acid cylinders and cylin ders for nitrous oxide gas and oxygen.
T h e second ty p e of shipping cylinders
c.
P e r c en t.
0 .0 6 0 .0 6
1
fr tfi f i
? ! - I
fi
dEL
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