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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 ENGIAYEERI~VGC H E M I S T R Y
was paid t o t h e percentages of different elements contained in t h e iron. Frequently what appeared t o be a high-grade KO.I Pig Iron, would, when analyzed, prove t o be a n inferior grade. Laboratory control established for us a reputation for quality a n d accuracy, a n d chemical castings, demanding t h e highest developed standards, immediately became one of our principal products. It is now fourteen years since we entered this field, a n d for a n active beginning joined issue with European manufacturers who were exporting to t h e United States t h e large pots used by caustic manufacturers and who largely dominated t h e American market as t h e domestic product was inferior. After careful research and development, assisted by t h e cooperation of our customers, we were finally able t o produce caustic pots of a better quality, i. e., giving longer life t h a n those imported from Europe. We next turned our attention t o chemical retorts of one t y p e or another for handling different acids, and t o acid eggs and acid kettles, a n d ultimately obtained equal results in t h e manufacture of these. After our success with these lines of chemical equipment, and several years before t h e outbreak of t h e present European war, we entered t h e field as manufacturers of vacuum dryers, pumps, and condensers, which apparatus has today so wide a n application in t h e chemical field. We developed a full line of vacuum dryers, consisting of shelf dryers, rotary dryers, d r u m dryers, and vacuum drying and impregnating equipment, as well as t h e auxiliaries which go with such apparatus, namely : vacuum pumps, condensers, expansion tanks, reclaiming devices, dust collectors, etc. This equipment, which we have highly developed with new and patented devices, is especially useful where rapid drying free from atmospheric variations is required, or where in order t o avoid injury t o t h e materials under treatment, drying must t a k e place a t low temperatures. Our vacuum drum dryers are constructed t o dry in large quantities and a t low cost and without a n y practical loss of material, emulsions, pulps, extracts, white lead, glue, milk, acids, dyes, and other liquids containing solids. These liquids are reduced t o dry forms economically a n d quickly a n d without danger of injury t o t h e quality of t h e material. We have so far manufactured j sizes of vacuum d r u m dryers, t h e smallest having a d r u m z ft. in diameter by 2 0 in. face, t h e largest j f t . in diameter b y 1 2 f t . face. All sizes are so constructed t h a t they may be easily cleaned a n d kept in sanitary condition, which is a vital consideration when handling food products. The smallest dryer is so constructed t h a t t h e casing over t h e d r u m can be readily moved back on a track so t h a t free access can be h a d t o all parts of t h e interior. The larger types are so arranged in size and convenience t h a t a man can enter t h e casing and scour all parts of t h e interior. Our patented method of applying the liquid t o t h e surface of t h e d r u m is t h e result of many developments in our particular machine, a n d t h e present arrangement assures a very uniform coating on the d r u m as well as a large output. There is a large reservoir in
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t h e bottom of t h e casing for holding a considerable quantity of material t o be dried. This material is taken. as required, by a circulating pump located beneath t h e dryer a n d delivered t o a supply pan immediately under t h e d r u m a n d slightly in advance of t h e knife or scraper, which removes the material. Only a small section of t h e drum surface comes into contact with the liquid material and, therefore, over threequarters of the d r u m surface is active a t all times in drying. The material is forced in t h e pan under sufficient pressure t o insure a uniform coating on t h e drum. The extra supply of liquid, which escapes on t h e side of t h e pan, where t h e film comes out, overflows into t h e reservoir in t h e bottom of t h e dryer. By t h e time t h e material reaches t h e scraper i t is dry enough for removal. I t is automatically scraped from the drum, falls into a conveyor a n d from there is removed t o a receiver. Two receivers are used, one on each end of t h e machine. While one is being loaded, t h e other is unloaded, a n arrangement which permits t h e machine t o be operated continuously. Where t h e d r u m dips into t h e main body of t h e liquid, i t is impossible, owing t o t h e agitation and foaming of t h e liquid, t o maintain always a constant level of t h e liquid material. This consequent change in level results in a n irregular immersion of t h e revolving d r u m surface, with a constant variation in t h e moisture content of t h e dried product, loss of continuous service, low output and heavy cost of operation. With our method, t h e d r u m does not come into cont a c t with t h e main body of liquid, and, therefore, a n y material can be dried satisfactorily whether i t foams in a vacuum or not. I t is also t o be noted t h a t as some materials give over their moisture more readily t h a n others, t h e speed of t h e drum, and t h e pressure of steam used in t h e drum, can be varied t o suit the material being treated. USES O F V A C U U M D R U M D R Y E R S
One of t h e most extensive uses for our vacuum drum dryer has been in the production of powdered chestnut and hemlock extracts. Formerly, these extracts were p u t on t h e market in a liquid state, containing approximately 50 per cent moisture. They were shipped in t a n k cars. These materials, with this moisture cont e n t , can be treated in our machine and dried t o a powdered form, having from 5 t o 7 per cent moisture content. This dried material can be packed into bags and shipped in this manner t o any part of t h e world. By handling i t in this form the market for t h e material is not only very much widened, b u t t h e expense and trouble of t a n k cars is eliminated, a n d consequently transportation expenses greatly reduced. Another important use for this machine has been developed in t h e recovery of dry sulfite waste from t h e waste liquors of paper mills. This product, owing t o its recovery in a dry state, now brings a handsome profit t o t h e paper mills, and secures another byproduct t h a t can be converted t o many useful purposes. It further enables t h e paper mills t o comply, actually a t a profit, with t h e laws prohibiting t h e pollution of streams with sulfite waste.
Feb., 1 9 1 7
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The approximate capacity of our j f t . by 1 2 f t . take t h e liquor from the filter presses, evaporate it as ~ a c u u md r u m dryer on t h e above mentioned extracts far as possible in open pans containing heating coils and sulfite waste. is 1000 lbs. of dry product per hour. and then dry t h e salt before fusion, either by means The cost of operation is extremely low. We have dried of heated air or by some other crude method. We, products where t h e cost. including depreciation and of course, easily determined t h a t a vacuum evaporator interest on investment, steam. power, labor, and should be installed for reducing t h e liquor t o a certain incidentals, has not exceeded 0.1 cent per lb. in re- density, thus doing away with t h e open pans. The ducing a product from a j o per cent moisture content problem t h a t presented itself was how best t o handle t o a commercially dry product under a 7 per cent t h e evaporated liquor. Our engineers and chemists assumed t h a t t h e vacuum d r u m dryer would be t h e moisture content. Vacuum shelf dryers a n d vacuum rotary dryers have ideal machine for treating t h e liquor as i t came from also been extensively used in t h e recent chemical devel- t h e evaporator, but i7-e found by actual experiment, opment in this country. They can be used t o great t h a t , owing t o t h e peculiar nature of t h e liquor, i t advantage in drying some of t h e chemicals derived from was very difficult t o secure under a vacuum a good coal-tar distillates. This use is in addition t o their coating on t h e drying drum. We next tried t h e vacuum rotary dryer, but found previously extensive application in t h e drying of both liquid and solid materials. These dryers are also t h a t this machine formed t h e product into large especially valuable in handling solid materials; t h e cakes or balls. It was impossible t o extract the moisture shelf dryer for sheet rubber, fruit, albumen, etc., from t h e interior of these masses without spending together with t h e rotary dryer, is available for use in considerable time in drying, our object here being, as drying reclaimed rubber, rubber compounds, paints, in all cases, t o produce t h e most economical method dyes, extracts, pastes, glue, soap, salts, starch, vege- for handling a given product. We found t h a t t h e extables, etc. Where t h e quality of t h e material is not perience we were having with this product coincided affected b y being tumbled or mixed while drying, or with t h a t which we had had on some other products, is not of too sticky a nature, t h e rotary dryer is a n which we worked out by using a n atmospheric d r u m dryer for reducing t h e moisture content to, say, approxideal apparatus for drying in large quantities. A t t h e outbreak of t h e present European War, when imately 1 2 per cent, a n d then finishing t h e prot h e supply of many materials never made in America, cess in a vacuum rotary dryer. This method produced was cut off, there was a sudden and large demand t h e desired results and furnished a beautiful sodium for chemical equipment, particularly in plants handling benzol sulfonate salt ready for fusing with t h e caustic t h e many products produced from coal tar. I n order soda. A later experiment has shown t h a t i t was not t o meet this demand, i t was important first t o make necessary t o reduce t h e moisture content in t h e sodium use of apparatus developed for these purposes in benzol sulfonate t o below 1 2 per cent before fusing Europe. I t was also essential t o design new types with t h e caustic soda, with t h e result t h a t the vacuum of apparatus t o suit conditions in this country and rotary dryer has been eliminated, a n d t h e atmost o make modifications in equipment which had been pheric d r u m dryer is used exclusively for handling the liquor as i t comes from t h e evaporator. developed abroad. We later found t h a t our atmospheric drum dryer Our company at once added t o its already well established engineering a n d consulting staffs. a corps has many uses in chemical plants. The patented sucof experienced specialists, who, with t h e coopera- cessful principles of operation in this dryer are t h e tion of chemical engineers associated with chemical causes for its exceptional success in t h k field. I t plants, developed machinery t o manufacture eco- embodies t h e principles of our x-acuum drum dryer. nomically the new products so greatly in demand, and The same patented automatic device for applying t h e we are to-day supplying apparatus for t h e manufacture liquid t o t h e drum, produces a uniform coating on t h e of a large number of these products, such as drum, a n d consequently a uniformly dry product. Aniline hleta-Nitraniline It is a n ideal machine for drying materials t h a t can Acetanilide Meta-Phenylene-diamine be dried rapidly and without injury under atmosAnisidine Meta-Toluylene-diamine Alpha-Naphthylamine Metanilic Acid pheric conditions, such as salts of sulfonic acid, sodium Alpha-Sulfonic Acids Naphthionic Acid Amido-Nsphthol Nitric Acid naphthalene sulfonate, and other similar products. Alpha-Naphthol Ortho-Anisidine Benzoic Acid Ortho-Phenetidine T h e machine is continuous in its operation and is a Benzaldehyde Para-Anisidine Beta-Naphthylamine Para-Phenetidine great labor saver; t h e finished product is uniform, Beta-Xaphthol Para-Nitraniline Beta-Sulfonic Acids Para-Phenylene-diamine and when desired for fusion, is in excellent condition Carbolic Acid Para-Amidophenol t o go direct from the dryer t o the fusion operation. Caustic Soda, etc. Phenetidine Dinitrobenzol Picric Acid One of t h e early demands after the beginning of Dinitro-Chlorbenzol Sulfur Black Dimethylaniline Sulfonic Acid t h e European War was for a reducer for t h e manuDiphenylamine Toluidine Gamma Acid Trinitrotoluol (TNT) facture of aniline oil. The improvements here are t h e H Acid Xylidine improved sludge unloading device which automatically D E V E L O P I I E S T O F ATXIOSPHERIC DRUM D R Y E R raises the 7-alve when open, and wedges it in position One of t h e first products vie were called upon t o pro- when closed ; t h e introduction of reversible liner plates, duce machinery for was synthetic phenol. The hollow shaft a n d rake for the introduction of steam method generally used in treating sodium benzol when desired. and t h e jacketed bottom for special sulfonate, before fusion with t h e caustic soda, was t o cases.
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B E T A - N A P H T H O L DISTILLATION A P P A R A T U S
Another development we have made’ is apparatus for t h e distilling of beta-naphthol. This consists of a still body, constructed of a special metal, and fitted with a cover in t h e usual way. T h e new feature of this still is t h e condensing and receiving system, t h e condensation being drawn into a n air-cooled condenser consisting of a single pipe. This pipe leads into a steamjacketed, 3-way valve, one of t h e valve openings attached t o t h e condensing pipe, a n d each of t h e other two leads t o a receiver. T h e steam in t h e jacket prevents t h e material from solidifying in t h e shelf, t h e material on entering t h e receiver passing between two glasses. By this means t h e operator can easily determine when i t is shut off, a n d change from one receiver t o another. These receivers are rectangular cast iron boxes with a door opening t h e full size a t one side. Inside of t h e receiver is placed a steel box with tapered sides which fits as neatly as possible t h e full size of t h e receiver. The beta-naphthol solidifies in this box, which is easily removed and is dumped by taking out t h e tapered box. I n addition t o t h e foregoing, t h e still is supplied with a large t a n k in which are placed baffles t o collect a n y material t h a t may pass a receiver. Beyond this t a n k two smaller receivers are supplied, one for containing t h e liquid t o neutralize t h e vapors if any should pass this distance from t h e still; t h e other receiver is for this liquor in t h e event t h a t t h e air current is reversed in t h e pipe. This allows t h e liquor t o flow from one t a n k t o t h e other as t h e case may be. T h e entire apparatus is evacuated by means of a dry vacuum pump, and t h e still is heated by a direct fire. RECLAIMING
HIGH
BOILING
POINT
SOLVENTS
FROM
WASTE
Another of our developments in t h e manufacture of sulfanilic a n d naphthionic acid a n d for reclaiming high boiling point solvents from waste, is a direct heated shelf retort, consisting of a chamber, provided with ducts passing from one side through a n opening on t h e opposite side. Between t h e ducts, a n d inside of t h e apparatus, are formed shelves. The one side of this retort is provided with a door opening t h e full size of same. T h e retort can be operated either with or without a vacuum. T h e retort when operated under vacuum is connected with a dry vacuum pump a n d a condensing system between t h e pump and retort. T h e material is placed on t h e shelves in pans a n d the hot gases from t h e furnace, in which t h e chamber is placed, passed through t h e inside of t h e shelves. The regulation of t h e temperature on each shelf is made b y dampers which permit more or less of t h e hot air t o pass through t h e shelf. This t y p e of retort is far more efficient a n d has a much larger capacity t h a n t h e previously odd shaped affairs used for this purpose, a n d is much more rapid in its operation. S P E C I A L AUTOCLAVES
Another improvement t h a t we have made is in t h e construction of autoclaves for t h e production of dimethylaniline. It has always been t h e practice t o use an enamel or silica lining in t h e autoclave, which
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has caused more or less trouble due t o t h e checking a n d cracking and final deterioration of t h e enamel. This led us t o develop a n autoclave which uses as a liner a highly acid-resistant cast iron. The difficulty encountered in this construction was t h a t t h e acidresisting metal is more or less brittle and would n o t s t a n d the high pressure necessary for t h e autoclave in t h e manufacture of dimethylaniline. This led t o our adopting t h e method of backing up t h e acid-resisting castings with a lead lining. ACID R E C O V E R Y
The rapid expansion of t h e chemical industry has brought up seriously t h e question of economical acidrecovery plants. I n this line one of our ingenious and unique developments has been t h e patented denitrating apparatus, which has for its purpose t h e distillation of nitric acid from a mixture of nitric, sulfuric a n d water. This particular form of construction of t h e machine enables this nitric acid t o be distilled off at a high strength and reasonably free from lower oxides of nitrogen. The reasons why results can be obtained from this apparatus and not from a n ordinary plain still are as follows: The new t y p e of denitrating apparatus presents a very large heating surface in contact with t h e acid mixture t o be treated. The temperature of t h a t part of t h e apparatus above t h e level of t h e acid mixture, cannot b y any possibility rise above t h e temperat u r e of t h e nitric acid vapors produced in t h e apparatus. By this means t h e strongest nitric acid vapors are not decomposed b y coming in contact with superheated metal surfaces. Therefore, t h e very strongest acids, a n d fairly free from lower oxides of nitrogen, will result. The distillation of t h e nitric acid is effected a t a much lower temperature t h a n is ordinarily possible. This is done by t h e injection of air a t t h e bottom of t h e machine, which keeps t h e acid mixtures in violent agitation, and t h e nitric acid held in t h e mixture is removed most effectively by t h e sweeping effect of t h e air. The direct heat from t h e furnace is drawn through t h e double U pipes in t h e apparatus, which are always covered with acid. By this means the greater part of t h e heat is directly absorbed a n d t h e balance of the heat contained in t h e flue gases, after leaving t h e double U pipes, is dr,awn around, thus giving additional heating surface a n d giving t h e greatest degree of efficiency in operation. The distillation of t h e nitric acid is therefore effected under almost ideal conditions, a n d by t h e use of the air t h e factor of mass action (which has t o be considered in a n ordinary still when nearly all t h e acid is distilled off) does not occur in t h e new type of apparatus. By this I mean t h a t when t h e ratio of sulfuric acid to nitric acid toward t h e end of a distillation becomes so great t h a t a very high temperature has t o be carried in t h e still, t h e nitric acid evolved must necessarily be weak. For example, in handling a guncotton displacement system t h e first run-off of spent acid is, of course, reinforced with nitric a n d oleum, b u t t h e second displace ment, which consists of approximately 18 per cent
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T H E J O C R S A L OF I N D I ; S T R I A L A N D ENGINEERING CHEiMISTRY
nitric, 60 per cent sulfuric and 2 2 per cent water, if placed in t h e ordinary still, will give on distillation a nitric acid of only about 78 t o 80 per cent K N O a and even at t h a t t h e temperature has t o be carried t o about 180 t o 190’ C. It is well known t h a t from guncotton spent acid, a n d particularly where oleum is used in making acid mixtures, enormous quantities of sediment will fall down t o t h e bottom of a n ordinary still, which is difficult t o handle, as i t tends t o choke t h e whole system. Now in t h e new form of denitrating machine, after 6 months work, there is not t h e slightest indication of sediment forming in t h e machine, a n d this can be readily understood, as t h e acid is kept in violent agitation during t h e whole time of distillation, thus preventing the settling of the mud which occurs in t h e ordinary still. 4 s to t h e kind of acid mixture best suited for this new t y p e of machine, I can s t a t e t h a t a n y acid mixture containing a nitric content above 2 per cent can be readily handled, and t h e nitrous contained in t h e acid mixture is t o some extent oxidized b y t h e large volume of air passing into t h e machine. As air is used in this machine, which, of course, means t h a t i t is saturated with nitric acid t o a n extent determined b y the temperature a t which t h e air vapors pass through t h e condensers, some form of tower is absolutely essential in order t o deprive t h e air of t h e nitric acid. T h e best form of tower for this purpose is a small one through which a very small quantity of water is allowed to trickle so t h a t a fairly strong acid can be obtained a t t h e foot of t h e tower, and no nitric acid allowed t o escape, a t t h e top. An ordinary form of absorption tower can be used for this purpose and need only be quite small: j ft. high b y 18 in. in diameter is quite sufficient. T h e commercial value of this apparatus in reference t o t h e handling of waste acid, may be sumniarized as follows: I-A stronger a n d higher grade of nitric acid can be obtained b y t h e new machine t h a n b y a n y of t h e older processes. a-The fuel efficiency per unit of nitric obtained is exceedingly high. 3-The capacity of t h e new machine per unit weight of acid handled is very much higher t h a n with t h e old type of still. 4-The space occupied by t h e new apparatus is only one-sixth t h a t required b y t h e older t y p e of still. j-The life of t h e new t y p e of apparatus is infinitely greater t h a n t h e old t y p e of still, as with t h e new form of apparatus only strong acids come in contact with t h e metal, and t h a t a t lower temperatures. Some improvement has also been made in evaporators for the chemical and other fields, which has been of great advantage in t h e development of chemical plants, starting with a small capacity a n d later desiring t o increase their production. Our evaporator has t h e advantage t h a t it can be doubled in capacity b y merely inserting a n additional belt and n e r tubes. This takes u p very little addi-
16 j
tional floor space and gives I O O per cent more cap acit y. Another development, which has met with considerable favor in chemical plants, has been t h e adaptation of our crystallizing p a n t o many uses in t h e drying and crystallizing of products which tend t o be sticky or gummy in the drying process. This crystallizing pan has been very efficient for concentrating and crystallizing material, permitting high temperatures. It has been used heretofore almost exclusively in this country for evaporating a n d neutralizing liquor of ammonia a n d nitric acid, a n d drying a n d crystallizing t h e finished product. This pan has also been equipped t o operate under vacuum, which provides a means for the drying of sticky materials a t low temperatures. .4 C I D - P R 0 0 P C A S T I N G S
A recent development in equipment for handling acids, is t h e so-called acid-proof or acid-resisting castings, which were first made in England, and later in the TJnited States. I n t h e United States we have kept pace with this movement and have manufactured not only small pipes as a substitute for stonemare for conducting acids. b u t have made various shapes and sizes of retorts. It is only recently t h a t medium-sized castings have been made with this metal. On account of t h e brittleness of t h e metal t h e problem from a foundry standpoint is a very difficult one, b u t advancement has been made, both in the size of t h e castings and in t h e shapes of t h e m for acid work. S o doubt t h e next two or three years will see a considerably greater improvement in t h e quality a n d size of this equipment. I believe t h a t as large and difficult castings are n o r being made in this country, if not more difficult ones, t h a n in Europe. T h e use of castings made of this metal is bound t o increase greatly on account of such castings being superior t o enameled equipment and stoneware for many classes of work. Our company has for some years had a chemical laboratory a n d a physical laboratory for work required in t h e carrying on of its business. We are now erecting a large laboratory building a n d will add very materially t o the equipment already in use, both for conducting many tests on our experimental dryers and evaporators, and also for research work in organic chemical lines. TTe expect t h a t there will be a demand for new apparatus t o handle t h e enlarging field of chemical products, and we hope t o be able t o serve in this development b y having a properly equipped laboratory and competent engineering talent t o carry on some of the research work. However, as t h e old proverb says, “Necessity is the mother of invention,’’ it is important, j r s t , t o know what is required before apparatus can be designed for meeting new requirements. I n t h e manufacture of chemicals, it is t h e man in charge of t h e plant who meets these new problems and who can call upon t h e research a n d designing engineer for his seraices in solving. I t is, therefore, important t h a t t h e chemists in charge of t h e manufacture of chemical products cooperate with t h e machinery manufacturers in speeding
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t h e advance in t h e design of machines t o meet new conditions. It is true t h a t great secrecy surrounds many of the chemical manufacturing processes in this country, and where publicity would affect t h e earnings of chemical companies, it is wise t o avoid undue publicity. But giving due regard t o t h e protecting measures required, I believe it is nevertheless possible for manufacturing chemists t o submit many problems t o t h e manufacturers of chemical equipment, which t h e latter can solve t o the benefit of both sides of t h e industry. BUFFALO FOUNDRY & MACHIHE CO~IPANY BUFFALO, ?\TEW Y O R K
EMULSIFICATION OF MINERAL LUBRICATING OILS' APPARATUS AND TEST METHOD By P. H. CONRADSON Received November 1, 1916
The simple apparatus a n d method of testing described, t o determine t h e emulsibility a n d demulsification (demulsification value) of lubricating oils such as steam-turbine, steam engine, and crank-case oils, have been used in daily routine work for t h e last year or more in t h e writer's laboratory, a n d have been found t o give satisfactory results considered from a practical service standpoint. They are simplifications of a much larger apparatus and more laborious method used previously for several years b y t h e writer, in connection with investigations of principally turbine oils in actual service, with reference t o trouble from emulsifications. Others who have suggested apparatus a n d test
I
c
FIG 1-011. EMELSIFYING TESTING APPARATLS
methods in connection with emulsion tests of lubricating oils, as Phillips,2 Herschel; and Bryan4 have writt e n at considerable length and in elaborate detail on t h e subject: therefore, this paper will be confined t o a brief description of t h e apparatus, method of testing, and interpretation of results. 1 Read before the 19th Annual hleetlng. American Society for Testing Materials, June 27 t o 30, 1916 8 J . SOC.Chem. Ind.. July 15, 1915. 3 Bureau of Standards, Washington, D. C 4 Experimental Station, Navy Department, Annapolis, Md.
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APPARATUS
Fig. I needs b u t little explanation. The apparatus consists of a 4-pint copper retort, provided with a delivery tube, which is joined t o a metal or glass pipe having a n inside diameter of about 6/16 in. and about I j in. long from t h e elbow. The lower end of this pipe is cut off diagonally t o prevent thumping. T h e glass cylinders are graduated t o 2 5 0 cc. They in. and a length have a n inside diameter of about I of about Q ~ in. / ~from t h e bottom t o t h e 2 j o cc. mark. They are I I ~ / Zt o 1 2 in. in overall length, and are made of thin glass, with a flat bottom. I n place of a copper retort for t h e generation of steam, a glass flask or any other suitable source oE steam supply may be used; likewise, ordinary 2 5 0 cc. graduated glass cylinders, of dimensions given above, may be used where emulsion tests are required only occasionally. METHOD O F TESTING
The cylinder is filled with distilled water u p t o t h e 20 cc. mark, then I O O cc. of t h e oil t o be tested are added. To churn t h e mixture. steam a t ordinary pressure is conducted through this oil-water mixture for t e n minutes. The amount of steam passed through is regulated in such a way as t o prevent t h e mixture from splashing over t h e t o p of t h e cylinder, b u t t h e rate may be as rapid as is practical. This is easily regulated by t h e height of t h e gas flame. The churning is begun from t h e time the temperature of t h e mixture has reached zooo F., or when the steam as such passes off t h e mixture. It usually takes from I t o I*/? minutes t o reach this temperature, depending somewhat on t h e body or viscosity of t h e oil. However, even churning with steam for 1 5 minutes does not seem t o make a n y difference in t h e results. When t h e churning is completed, t h e cylinder is immersed for one hour in a water b a t h , kept a t a temperature of 130' F. During this time t h e cylinder a n d its contents are momentarily inspected a t intervals t o note t h e behavior of t h e oil mixture. At t h e expiration of one hour t h e cylinder is removed from t h e water b a t h a n d t h e contents are examined for t h e following: (I) The number of cc. of separated clear or turbid water. ( 2 ) T h e number of cc. of separated emulsified layer. (3) The number of cc. of separated clear or turbid oil above t h e emulsified layer. (4) The percentage of water or moisture in t h e separated oil above t h e emulsified layer. The number of cc. a n d condition of t h e emulsified layer is a n indication of t h e emulsion-forming property or quality of t h e oil. The number of cc. of clear or turbid oil above t h e emulsified layer, less t h e percentage of water or moist u r e contained in t h e oil, is t h e percentage of demulsibility of t h e oil. T h e condition of t h e separated water or watery liquid under t h e emulsified layer, if any, gives a n indication also of t h e behavior of t h e oil in actual service. T h e amount of water held in t h e oil above t h e emulsified layer may be determined as follows:
