October, 1933
INDUSTRIAL
AKD EKGIKEERIKG CHEhlISTRY
CAUSESOF FAILURE OF EQUIPMENT Failures of this type of equipment, other than those resulting from normal wear over a period of years, may be classified as follows: Use of pressures in excess of those recommended by the manufacturer. Localized overheating, such as from the use of direct flame or by allowing a stream of cold liquid to impinge on a small area within a jacketed tank that has been heated to a high temperature by a previous batch. Use against chemical conditions for which the equipment was not originally specified. Glass enamels vary in resistance and the conditions should be clearly defined prior to manufacture of the equipment. Fracture from mechanical abuse, such as a heavy metal nozzle at the end of a hose. Fracture from strain at clamped or bolted flanged joints. This can readily be avoided by the use of suitable gaskets and by tightening uniformly so that the metal itself is not distorted. As a rule, it is entirely possible to recondition glass-lined steel equipment. After removal of jackets and accessories, the original coating is sand-blasted off, corrodcd steel repaired by welding, and new coats of glass-enamel applied. Methods of repairing glass enamel in the field have been given exhaustive study, and satisfactory materials are available for the majority of chemical conditions to which this equipment is subjected, provided that the area of exposed steel is comparatively small. For example, recessed gold plugs, for areas of small diameter, are extremely satisfactory
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and in no way shorten the service life of the adjacent glass enamel. Ceramic patch repairs are frequently employed, and with good results if care is taken in their application. One example of this is a large still and piping assembly, exposed to wet chlorine and bromine vapors, which has already been kept in service for over a year by means of ceramic patches, after a plant accident had caused damage of the glass enamel a t numerous points. USES
Glass-lined equipment finds many apecific uses in the chemical and allied industries. Much of the nitration, sulfonation, and chlorinaton, as in the manufacture of dyestuffs, is done in such apparatus, which is also used in preparing dyes for use in the textile plants. Such equipment has its place in the production of synthetic I esins, pharmaceuticals, toiletries, cellulose acetate, gelatin, lacquers, rubber accelerators, and in the refining of precious metals, to mention a partial list. Kumerous industries specify glass-lined equipment for mixing and storage purposes. Glass-lined steel tank cars, for the bulk transportation of various liquids, constitute an extremely interesting development of the past few years. They were designed primarily for fluid milk, and several hundred 6000- and 8000-gallon cars are now in daily operation for this purpose. Their use is gradually broadening into other fields such as grape juiw, tomato pulp, mineral waters, laundry bleach, etc. RECEIVED February 1, 1933.
Studies in the Friedel and Crafts Reaction Effect of Size of Aluminum Chloride Particles in the Preparation of Some Keto Acids P. H. GROGGINSAND R. H. NAGEL, Bureau of Chemistry and Soils, Washington, D. C.
I
The effect of the size of the aluminum chloride the material was of the dimenparticles in carryingout !he Friedel and sions given, but in all cases a Friedel and Crafts reaction, small quantity of the p o w d e r p r a c t i c a1 considerations synthesis of 4'-chloro-2-benzoylbenzoic acid is w o u l d recommend t h e u s e of TI;aspresent. closely related to the eficiency of the agitation proaluminum &loride in the form The first s e r i e s of e x p e r i of granules or small lumps. As vided. With, better agitation, particles u p to the ments was conducted in Niter, size of a pa have been used with Success in three-necked, r o u n d - b o t t o m compared with powdered material, these would be less hythe preparation the keto acid. ~~~~~~l of the flasks. The procedure employed g r o s c o p i c in s t o r a g e and in is described in previous publicaliberated hydrogen chloride gas from the reaction handling and less troublesome in tions (s). In t h i s s e r i e s the chamber increases the yield* The solubility of delivering to the reactor ( 2 ); small glass stirrer (the size being finally, the l a r g e r p a r t i c l e s 4'-chloro-2-banzoylbenzoic acid in water at varil i m i t e d to 1.5 inches, or 3.8 cm., bv the neck of the flask) would not react a s r e a d i l y , ous temDeratures has been determined. T o avoid solubility losses, the keto acid should be rotiting a t 150 r. p. in. was inthus contributing to a better regulated initial reaction. On a d e q u a t e to provide a homoJiltered at room temperature and washed with the o t h e r h a n d , t h e u s e of geneous r e a c t i o n mass, powdered a l u m i n u m chloride cold water. data in Table I reflect this condii s frequently specified i n t h e tion. The finer particles of alumipublished literature. The purpose of this investigation was num chloride contributed to a more homogeneous reaction to determine the effect of the size of the aluminum chloride mass and hence to better yields. An increase in the reaction particles upon the yield of keto acids. time under similar conditions did not effect any improvement. With the object of providing more adequate agitation, the EFFECT OF TYPE OF AGITATIOX next series of condensations was carried out in an enamelThe preparation of 4'-chloro-2-benzoylbenzoic acid was lined, round-bottom vessel of 8 liters capacity. The reactor employed as a vehicle for determining the influence of the was fitted with an anchor type stirrer rotating a t 25 r. p. in,, size of the aluminum chloride particles. Four sizes were in- to which was attached a sheet-iron blade that practically vestigated, lump (approximately 15 to 20 mm. diameter), scraped the bottom portion of the vessel. The data in Table pea (approximately 4 mm. diameter), sea sand (approxim:itely I1 show that a slight increase in yield was obtained under 0.5 to 1 mm. diameter), and powdered. The greater part of these conditions. S C A R R Y I N G out the
crafts
"
&
niitmtioii IUS t i i e elrarges that sciiiie of the aluniiiium cliloride particles did not react. These were covered Iry :I reddisli coating of t,lic :duniiuuui c l i l ~ ~ r i i l e c o ~ i i pof l ethe r keto iiciil, which l1ad rffcctirdy scaled the interior of the lunip, tliiis leading to a lower yield of the keto acid. Witli the peaed particles, tlie product ciuiie out of the rcnction vessel ,~ n honlogeiio~ius pasto. n these results it niny be c u i i c l i i d r d that, it is not IN ry to USE powdered alurnii i i i i r i cliloridi! to ,secure t,lw liest r c d t s , i f adeqiiiite agitation is providid.
res?tilili ,>
lllNSS
1IN:jirecediiig data and oi,servatimn lead tii the c ~ ~ ~ ~ c l u s i ~ ~ ~ tirat in the liquid-plmse l+icriel snd Crafts syrit,li ;acid$it is necessary 1.0secure a lromogeneous reaction n~assand to remove the volatile product of the reaction, hydrogen dtloride. The apparatus liest suited for this purpose shoulil therefore provide thoroiigli mising, should scrspe the walls of t i i e reactor, and should breek t,he surface of t l i e re:ict,iori inass to facilitate the escape of the liberated hydrogen ihloride. It is apparent, that tire ordinary type of anchor stirrer f:rlls short of the desired requirements. Agitators OS t,lw t.ype illustrated in Figures I arid 2 appear to have greater nierit. (Since the Friedel arid Cra,fts reaction must he carried out under ariliydrous conditions, t,lie reactor vessel runst lic provided with a tight eover, suitable flanged joints and conni&iiiis, siid stuffing boxes so as to prcclude the ingress of irioistiirc diiring tlrc coiirse of tiie reaction.) the iriixt,ore. The air \vas dried 1,y means of ciilciurii clilorido and 15.8s rvarrried by passing it tlirwgl, an elcetrio:iliy heated tulle. The x n t of the rraetioii vessel WIS :rttiiclred to a suet,ion line, and a reduced prcssim! of 1.5 to 2.0 i t i a l ~ e s(3.8 to 5 cm.) of water was irraiiitxined. The liemfir!inl rcsrrits of this pr~icedme,indicated i n Table III, are itttrilriited to the more effective rcrriovril of tlie IiberiLted hydrogen cliloride gas from the reacting mass. The d a h in Tablcs I1 arid I11 sliow that. with the exccn-
