Oct.,
1911
T H E JOURNAL O F I.VDUSTRIAL A N D E N G I N E E R I X G C H E M I S T R Y .
D is made of thin sheet iron and is oxyacetylene welded. The winding is a molybdenum ribbon, 0.184 mm. thick, 2.54 mm. wide and 44j cm. long. I , I are heavy copper leads. fastened to the ends of
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The clarifying compartment consists of a cylinder filled with a series of conical-shaped, pressed-steel disks, one above the other, about inch apart and held rigidly in position by a central feeding device. The filtering chamber or upper section is also cylindrical in shape, b u t of less diameter. The liquid first enters the bowl a t the point A through the feeding device in the center and drops to the bottom of the clarifying compartments B, where much f sediment is retained. It is then forced outward by the great centrifugal force through openings a t the bottom to the periphery of the compartment C, where the bulk of heavier sediment is deposited. The liquid is next drawn to the center between the several disks. The purpose of these conical disks is to divide the liquid into thin layers, thus the friction on the disks above and below causes it to revolve rapidly and the heavier part, or balance of the sediment, is grad-
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D ' I'rg 2
the coil by twisting thc latter about them. C is the powdered silica packing ; F.F is some asbestos wool, used to prevent the escape of hydrogen at the ends of the casing. H and G are the hydrogen inlet and outlet tubes respectively. I2 is a rubber stopper. With this furnace a temperature of 1600' C. is readily attained. At this temperature it calls for 80 volts and 14.3amperes. The two furnaces above described are adapted to heating the charge in a n atmosphere of hydrogen. In case i t were desirable to heat in an oxidizing atmosphere, i t would be necessary to replace the very porous alundum by porcelain, as otherwise the furnace winding would become oxidized.
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RESEARCH LABORATORY, G E S E R A I . E L E C T R I C COMPASY.
SCHENECTADT, S7 1 ' .
DE LAVAL CENTRIFUGAL CLARIFIER AND FILTER.
The makers claim that in this machine they have solved the problem of the separation of solids from liquids-namely, the separation of a small amount of sediment, etc., from a solution-and t h a t it has already stood the test of practice in the clarification and filtration of varnishes and allied products, oil pharmaceuticals, patent medicines, fruit syrups and extracts, in fact, of many liquids containing either a sediment deposit or the finest flock or both. But as this centrifugal machine will undoubtedly prove useful beyond its present sphere the following notes on its construction and operation should prove valuable. An outside view of this machine is given in Fig. I , which shows the steam-turbine style for direct steam connection. The largest size of this type has a height of 46 inches and requires a floor space of 18 inches by 24 inches, which indicates a big saving in floor space over other separating methods. In works where shafting is already installed the machine may be used with belt drive, while the smaller sizes of the machine are entirely practicable for running by hand. Fig. z is a section of the clarifier and filter bowl. I t contains the two compartments where the work is done, namely, the lower clarifying compartment and the upper filtering chamber
Fig. 1.
ually forced to the under side of the disk above, thence down and out to the pocket C, while the thoroughly clarified liquid passes to the center and is forced upward and out into the sccond or filtering chamber at, D. When the liquid enters this compartment fully 99 per cent. of thc. s d i m e n t a n d foreign
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T H E J O U R N A L OF 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 .
matter has been removed, thus leaving a small though very important work for the filter t o accomplish. The filter chamber is filled with a series of horizontal corrugated plates and perforated retaining rings, between which are placed one or more thicknesses of
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Oct.,
1911
is possible otherwise and continue t o deliver a product of the required fineness. Where it is desirable t o aerate the products to be handled, the separator can be made t o automatically aerate the liquids as they pass through it and thus do away entirely with the necessity of air pumps or other equipment and labor necessary for aerating purposes with other filtering processes. This machine is built b y the De Lava1 Separator Company, 165 Broadway, New York City. The manufacturers state t h a t with due care this clarifier and filter will last a lifetime. The average operator finds no trouble whatever in adjusting or cleaning any of the machine's parts and keeping it ever ready t o perform its work. The chief advantages claimed for this machine are as follows: The clarifier and filter will take any product to which it is adapted immediately after compounding and deliver continuously (except for occasional cleaning of the machine) a finished article ready for the market. I t thus greatly reduces the capital necessarily tied up in settling tanks with other methods. The manufacturer claims a n average saving of 90 per cent. in filter paper and cloths and their subsequent washing and cleaning over that required b y other processes, also a saving of liquid absorbed b y the
Fig. 2 .
filter material, paper, felt, cloth or whatever mal; be best adapted to the work in hand. The liquid is forced from compartment D upward into the compartment E , which is a narrow space between the periphery of the filtering chamber and the filtering disks. This allows a channel for the liquid to pass up, from which i t is delivered into the several compartments F, where it is forced through the filtering material G into compartment H. Here it is again forced t o the center and upwards through channel I to the discharge point J and into the large cover from which it flows into the receptacle awaiting it. The functions of the clarifying and filtering compartments supplement each other very thoroughly. The liquid is so thoroughly clarified by the disk system in the lower clarifying compartment t h a t i t leaves but a small amount of work for the filter to perform. Then, too, the filters being placed horizontally are substantially self-cleaning, for as the sediment or flock forms in any volume on the filters the centrifugal force throws it off and it is deposited at the outside or periphery of the compartments. Thus the filter material will do its work very much longer than
Fig. 3.
filter paper and that lost by evaporation or dripping with other methods, a saving of liquid, labor and the losses that sometimes occur from punctures in paper and a big saving in floor space.
AN AUTOMATIC PIPETTE. B y GEO.
E. BOLTZA N D
CHAS
J. SCHOLLENBERGER
Received August 10, 1911.
Every analyst who makes a large number of determinations of the same character, each involving
