68 2
T H E J O U R N A L OF I X D U S T R I A L AND E N G I N E E R I N G C H E A 4 I S T R Y .
A small stream of water is drawn from the main
SAMPLING CONE.
through valve 0 , passing through the small jacket P, where itpartlycools the water in the i n t e r i o r coil M. From the jacket P, the water flows through V and upwards through K within the steam jacket C, where it is heated to 180200°F The heated water flows past the thermometer T , through the coil M , and finally into the cooling coil of the water jacket D. The water thus heated and cooled flows out below, FIG.1. when the faucet X is opened, either into a cup or into a bubble fountain.
By C. W. KNEFF. Received M a y 28, 1912.
Sept.,
1912
Every one who does ore sampling has noticed that the lumps always roll to the bottom of the pile, when the ore is piled in the form of a cone preparatory to quartering. When the cone is built up by placing shovelfuls of ore on the apex of the cone, this is unavoidable and segregation of lumps and fines always results. By the use of a hopper such as is shown in the sketch, this condition can be almost entirely overcome. The ore is shoveled into the hopper, and allowed to run through the hole in the bottom; each piece of ore remains practically where it falls and when the pile is flattened out for quartering there is no segregation of coarse and fine to be seen. The sketch shows a I inch hole in the bottom of the hopper, but for some work i t should be larger, e . g., for coke, which has a tendency to choke the opening and stop operations. For general work I find a hole
Very efficient cooling can be secured by making coils M and S of tin lined brass pipe. These can be of thin material, since the water pressure inside and outside of them is always alike. I n practice, with such an arrangement, no difficulty was found in cooling the water for drinking t o within '2 of the temperature of the cooling water in the jacket D. For some reason, not well understood, the water thus heated and cooled under pressure is more palatable to some observers than the untreated water supply.
i,Y n.
The water pressure should be about 2 5 pounds greater in the main B, than the steam pressure in A, in order that the water may not boil in the pipe K, which may be made of I / ~ or 3 / 8 inch galvanized or tinned iron pipe. I n cities where the municipal water supply is known t o be contaminated with sewage, causing typhoid fever, the pasteurization of water as it flows from the pipes for drinking purposes appears desirable. In large office buildings, factories, schools, etc., where steam pressure is maintained throughout the summer, and where water flows continually through the mains for supplying toilet rooms, work rooms, etc., such an arrangement for pasteurizing' water for drinking purposes might find useful application. The amount of steam used in such an apparatus is small, because the regenerative cooler P prevents waste of heat. For residences, either gas or electric heat might be substituted for steam in such an arrangement as the one described above. UNIVERSITY OF WISCONSIN, MADISON.
FIG.
1.
C O X E FOR SAMPLING ORE.
of 1 3 / ~ " diameter most satisfactory, but I have some funnels with smaller openings, which I can drop inside the main funnel, and obtain any size of opening desired. As the sample come's from the crusher, the largest piece is about 3 / / , inch and is mixed with considerable fines. This is passed through the hopper three times, which gives a very uniform mix, much better than can
Sept., 1 9 1 2
T H E JOCR.VAL O F ISD1,’STRIAL Ah‘D E-VGINEgRIA‘G C H E - T I I S T R Y .
be obtained by the common practice of piling with a shovel. After quartering, the portion retained is passed through the cone again, and so on till the sample weighs from 8 to I O pounds, after which i t is passed through a K O . 8 sieve and finished in the usual way. SHOENBERGER ETREI. WORKS, PITTSBURGH. PA.
A LABORATORY GLASS-FURNACE. B y S. R. SCHOLES.
Received June 1 7 , 1912.
Experimental glass-making has always been attended by the difficulty of getting the necessary temperature. We have installed in this laboratory a furnace burning natural gas and using the regenerative principle common in glass-factory practice. The designing and construction of this furnace, following our rough sketch, were undertaken by Messrs. Armstrong and Lytil, furnace builders, of Pittsburgh.
683
and connects by a suitable valve with an air inlet. A twenty-five-foot stack is used. Gas is supplied through one-inch pipes, under a pressure equal to eight inches of water. The gas is not “regenerated” but enters, through a three-eighthsinch nozzle, into each regenerator column just below the level of the bench. The furnace can be brought from room temperature to its full heat in about twelve hours. I t is usually maintained at 135oo-r4oo0 C. but a h gher temperature can easily be reached, which is practically limited by the softening of the crucibles. The best efficiency is obtained by reversing gas and air supply every twenty minutes. The gas-consumption is about 2 5 0 cubic feet per hour. Much of the credit for the design of this furnace is due Prof. S. L. Goodale, of the School of Mines. ITDUSTRIAL RESEARCH LABORATORY, UNIVERSITY OF PITTSBURGH.
THE DETERMINATION OF CARBON IN STEEL BY DIRECT COMBUSTION IN THE NEWEST FORM OF SHIMER CRUCIBLE, WITH THE AID OF A PERFORATED CLAY DISC. B y FRANK0 . KICHLINE. Received M a y 31, 1912.
FIG. 1
The accompanying photograph gives a n idea of the general plan of this furnace. It is constructed of standard sizes of furnace blocks. An arched roof of silica brick covers a crucible bench 42 X 2 7 inches, a t the ends of which the gases enter from the vertical regenerators, through openings 9 X 1 2 inches There is thus a space accommodating several crucibles of generous size, such as size “M” of the Battersea make. The regenerator columns enlarge below the bench to 16I/$ X 2 1 inches and are 4 feet high. They are filled with the usual silica checker brick. From the foot of each regenerator a horizontal flue leads to the stack
,
In THISJ O U R N A L , for October, 1909, Dr. P. w. Shimer described a simplified form of his crucible for the determination of carbon in steel by combustion. Two improvements have been made in the use of this crucible for direct combustion. These improvements are ( I ) an increase in the diameter of the crucible, and ( 2 ) the use of perforated clay discs instead of asbestos for covering the charge of drillings. It has been the practice, in the direct combustion of carbon in steel, to place the drillings in a No. ooo Royal Berlin porcelain crucible two-thirds full of silica sand, placing this porcelain crucible inside of the Shimer platinum crucible with a pair of forceps, and covering the charge with a layer of ignited asbestos about 3 j 4 inch thick. The asbestos serves to keep the drillings in place and prevents heat radiation to the water-cooled stopper. A slight increase in the diameter of the Shimer platinum crucible made it possible to use a No. 00 Royal Berlin crucible instead of the No. ooo size. The No. 00 size has a t the top an area 1.41 times that of the No. ooo size, and is filled to only one-half its depth with silica sand. This has the obvious advantage of permitting the use of a heavier charge, full factor weight ( 2 . 7 2 7 3 g . ) , or if the factor weight is preferred it will be less crowded. Dr. Shimer has recently adopted this increased diameter for his standard size crucible. Ignited asbestos as a covering for drillings is very efficient. While results are not vitiated by the presence of ignited asbestos, i t is obvious that the packing in of a layer of asbestos before each burning, and its removal after burning, are both time-consuming and inconvenient, and the source of much dirt around the carbon work table. I n trying to obviate the use of asbestos, the writer
