Monatsschrift des Württembg. Vereins für Baukunde in Stuttgart: Sitzungs-Protokolle / Verein für Baukunde in Stuttgart

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Zeitschrift

Persistenter Identifier:: 1466506725020

Titel:: Monatsschrift des Württembg. Vereins für Baukunde in Stuttgart

Erscheinungsort:: Stuttgart

Frühere Titel:: Sitzungs-Protokolle / Verein für Baukunde in Stuttgart (1870-1884); Versammlungs-Berichte / Württembergischer Verein für Baukunde in Stuttgart (1885/86-1892)

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Strukturtyp:: Zeitschrift

Sammlung:: Zeitschriften

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

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Persistenter Identifier:: 1466506725020_1881

Titel:: Sitzungs-Protokolle / Verein für Baukunde in Stuttgart

Untertitel:: : vom ... Halbjahr ...

Jahrgang/Band:: 1881

Verleger/Verlag:: W. Kohlhammer'sche Buchdruckerei

Erscheinungsort:: Stuttgart

Umfang:: getr. Zählung

Sprache:: deutsch

Strukturtyp:: Band

Standort:: Universitätsbibliothek Stuttgart

Signatur:: 1Ba 280-1881

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

166 American Association for the Advancement of Science. { CrgacaL News, average of about 5 per cent of moisture, and as soon as it may be recovered in a very simple manner. The gase this condenses into water there is generally a notable de- can be mixed with a little air if enough of oxygen is not crease in the quantity of fume which subsides. ilready present, and then propelled by means of a steam The fourth class of condensers consists of those which et through a heating apparatus similar to the hot blast have for their principle the passing of the smoke through eaters used in iron smelting works, and the hot sul- a body of water. This principle has been tried in various >hurous acid steam and air passed through common salt ways. The old Stagg’s condenser, in which the smoke according to Hargreaves’s patent process. By this means was drawn in great volumes under the surface of water ead or copper smoke will be rendered not more pernicious by means of powerful pumping is now nearly, if not alto- han that from ordinary chimneys. Any arsenic or zinc gether, obsolete, which reaches the condenser is dissolved in the water, and Our experiments showed that mere bubbling the smoke in that way separated from the lead fume, which subsides through water from a perforated pipe, for example, haslittle io the bottom. The apparatus was tried with hydro. effect in stopping the fume. We made experiments to chloric acid vapour and condensed 97% per cent; of com- prove this, both on the large and small scale. Inthe mon salt vapour it condensed g3 per cent. large one we passed the smoke through a number of hori. We use a Roots blower, with iron revolvers for forcing zontal perforated pipes submerged 11 inches in water. Our he smoke through the apparatus; from 2% to 3 horse- assays showed that only 30 per cent of the fume was Jower is amply sufficient to work a condenser large arrested. Our experiments on a smaller scale gave even :nough for a furpace to smelt 15 tons of lead ore per worse results, The reason why simple bubbling through iwenty-four hours. The weight of a condenser for that water succeeds no better than the shower-bath principle is size of furnace is 18 cwts. The smoke should be cooled that in both cases precisely the same cause operates, viz., lo about 120° to 130° F. by passing it through iron pipes, the surface-tension of the water, which is just the same or any other kind of flue. This is necessary to prevent whether for a concave or convex surface of equal extent. rapid evaporation of the water with which the condenser We can prove that fume is difficult to wet by coating a is supplied. Itis very important to cool the smoke as far glass plate with it, and then dropping water on it while it as possible so as to have a smaller volume to pass, and is held at an angle of about 60° to the horizon: the drops ‘hereby save both power and cost of a larger apparatus. are reflected off without wetting the plate. This question of surface-tension was well illustrated by an experiment made at the suggestion and in the presence of Mr. Alfred E. Fletcher, one of Her Majesty’s Inspeéors. Equal quantities of smoke were bubbled through a wash- bottle arrangement, filled first with water, and then with ordinary rape oil. The oil, which has less than half the surface-tension of water, caught more than three times as much fume as the wates. The considerations led us to seek for some way of destroying the surface-tension of the bubbles, and we hit on the device of using fine wire gauze, made of any metal capable of resisting the corrosive a®ion of sulphurous acid. Copper gauze answered perfectly. In our new apparatus we use wire gauze having about 15 meshes to a lineal inch, the meshes being ahout 1-20th of an inch wide. A number of gauze diaphragms are arranged one above another in horizontal planes, and at small distances apart. The whole are submerged in water. The smoke is equally distributed under these by means of a horizontal series of perforated pipes. The gauze diaphragms do not add much to the resistance which the smoke current has to overcome in its passage through the apparatus ; three diaphragms of the size mentioned above add about } an inch of water pressure. The depth of water usually employed is 7 inches above the perforated pipes, and with this depth the water gauge indicates a resistance of about ro inches, $ an inch only of which is due to the gauze, the remainder being due to the depth to which the smoke depressesthe water at the inlet passages. The ascending gases set up an upward current of water through the gauzes, and to promote a steady circulation of this a return passage is provided, Although we usually work with three diaphragms of wire gauze, double that number may be used without adding appreciably to the resistance, and by so doing still more perfect results may be obtained. Each square foot of area of the diaphragm space is capable of passing about 40 cubic feet of smoke per minute, and when a blast- lurnace is employed for smelting lead ore about 1 foot of area will be required for each ton of ore smelted in twenty. four hours. During the past six months almost daily assays have been made of the smoke before it entered and after jt left the condenser. These have with a few exceptions ex- ceeded g5 per cent of fume caught, The average has been 98 per cent, and in a few cases as bigh as gg} per cent of the metallic contents of the smoke has been caught, After the lead has been removed from the smoke the large quantity of sulphurous acid which is usually contained in Tus Association held its twenty-eighth meeting at Sara- toga Springs, N.Y., beginning August 27th, 1879. The meeting was a memorable one, both on account of the large attendance and the great value of the papers pre- sented. The Association was honoured by the presence of an unusually large number of its Ex-Presidents, no ess than nine being on the platform at one time. The Presiding Officer, Prof, G. F. Barker, M.D., of the University of Pennsylvania, was very happy in condu&ing :he business of the Society, his genial humour in nowise detracting from the dignity of the occasion, and serving as 1 pleasant refreshment. _. The other officers of the Association were as follows :— Vice-President of the Physical Section, Prof. S. P. Lang- ey, of Alleghany, Pa.; Vice-President of the Natural- History Se&ion, Major J. W. Powell, of Washington, 0.C.; Permanent Secretary, Prof. F, W. Putnam, of Zambridge, Mass. In the absence of Dr. Geo. Little, of Atlanta, Ga., Dr. H. Carrington Bolton, of Hartford, who was General Secretary at the St. Louis Meeting (1878) was continued in office. The Chairman of the Subsection of Chemistry, Dr. Ira Remsen, of Baltimore, was unfortunately prevented from attending, and Prof. F, W. Clarke, of Cincinnati, took :he position, One of the features of these meetings is the Address of the Retiring President. On this occasion Prof. O. C. Marsh, of New Haven, had the duty to perform: his sub. et was “ The History and Methods of Paleontological Discovery.” Vice-President Langley gave an Address on ‘ Solar chysics,” a subject to which he himself has materially “ontributed ; and Major J. W. Powell gave an Address on “ Mythologic Philosophy,” having special reference to the nythologics of the Indian tribes. Dr. Ira Remsen’s Address was a plea for the study of Organic Chemistry, a branch which he claims is too often neglected in the courses prescribed in colleges and scien- iific schools. These Addresses will appear in full in the annual volume of Proceedings. Heartily welcomed by the meeting was the distinguished astronomer Dr. Otto Struve, Director of the Pulkowa Ob.

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Inhalt / Download: Chemical news and Journal of physical science (Volume 40, 1879 (July - December))

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