US1377478A - Apparatus for generating gases and treating solutions therewith - Google Patents

Description

v H. R. HANLEY. APPARATUS FOR GENERATING GASES AND TREATING SOLUTIONS THEREWITH.

APPLICATION F|LED4N0V.13| 1919.

Patented May 10, 1921.

UNITED STATES PATENT OFFICE.

HERBERT R. HA1\TLEY, or SAN raaucrsco, CALIFORNIA,

APIIARATUS'FOR GENERATING eases AND TREATING SOLUTIONS trn'nnnwrrn.

This invention relates to an apparatus for the generation of gases, particularly hydrogen sulfid, and to the treatment of liquids or solutions with the gases so generatedfor purposes of purification or otherwise.

The invention has for its general objects the economic utilization and complete con-I sumption without waste of the materials used in the generation of the gas, and of the gas itself; the convenient discharge of the products of the reaction andthe thorough and even treatment of the solution to be acted upon to the desired extent without local overtreatment. or. removal therefrom of sub stances not intended. v

In the drawings Figure 1 is a diagrammatic view of. an apparatus arranged in accordance with the invention. Fig. 2 is an end elevation of the generating drum.

Inthe generation of certain gases by the action of an acid upon a solid reagent, for example, in the generation of. hydrogen sulfid by the well known reaction between iron sulfid bearing bodies and acids, it'is found that, as the action proceeds,.the mane gas generation becomes gradually, retarded due.

to the sealing over of the active solids by the inert products of the reaction, and that finally the generation ceases before either of I the reagents has been completely consumed.

It has also been: found that, in order tosecure eflicient gas generatlon, it is necessary to avoid gas pressure. within the generator. Thepresent invention accordingly contemplates the provision of an improved gen-' erator wherein-the mass contained therein may be conveniently agitated in such a manner as to prevent the retardation of gas gen eration by the causes above referred to, and also wherein a condition of partial vacuum may be maintained within the generator in order to prevent the development of fluid pressure therein, said generator being also of such a construction that the residue remain- Specification of Letters Patent. Patented 10, '1921 Original application filed April 15, 1919, Serial No. 290,214. Divided and H this application filed November 13,1919. Serial No. 337,676. 1

ing after the reaction is fully completed may '2 be conveniently removed. f c To these ends the generator as shown com posed of wooden staves and lined with lead. Thelead lining is preferably protected from abrasion by an inner wood covering. The outside wood staves are held together by the usualhoops or bands 11. In addition tothe hoops, there are. circularrails of suitable cross section fastened to the drum and constituting a circular track. The cylinder or prises a cylindrical vessel 10 preferably comdrum 10is mounted upon wheels12 upon which the rails or hoops 11 rest, said rails or hoops constitutin a circular track where'- by sald drum may be readily rotated upon said wheels, as by means of a sprocket chain 13 engaging a suitable toothed. ring 14; car- Y e I i ried by said drum adjacent one end. Said drum 10 isprovided with an openingormanhole 15 normallyclosed by a suitablecover and through which the active solids are in troduced and the inert residue discharged, with theaxial inlet '16 .for the acidor other actlve liquid, and withan axial outlet 17 for the gas generated; The active. solids, in more or less broken or finelyldivided form, may be supplied from [a hopper or recep: tacle 18 having a chute '19 adapted, when the drum 10 is in theposition shown in Fig. 1

and the manhole cover removed, todischarge thedesir'ed quantity. of said solids through said manhole into the interior of. the drum. The acid or other active liquid may be stored in a tank 20 having a valve-controlled'outlet 21 from which} leads a pipe 22 communi eating with a second pipe 23 leading to the 24 adapted to direct material discharged from the drum 10 intoja suitable receptacle or car 25, whereby said material may be disposed of in any desired way.

. inlet 16. Beneath; the wheels 12 is a hopper" In operation, thenecessary reagents hav ing beensupplied to the drum .10 from the receptacle 18 and tank 20, respectively, the

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manhole cover 15 is replaced and the reaction allowed to proceed the usu almannor, the gas generated passing, out of i the drum through the outlet 17. When' the generation ofgasbegins to be retarded, due

by causing the inertcoatings to be removed by attrition, and newsurfaces to be pro.-

1 0.5 to the coating of the active solids with inert l when combined with the acid root to form the resultant neutral salt, will be retained in solution in the liquid present without crystallization. Taking, by way of example, the generation ofhydrogen sulfid by the action of sulfuric acid upon iron sulfid, if the usual strong or relatively concentrated acid is used, say 300 grams of sulfuric acid per liter of liquid, this acid will be capable of dissolving Or combiningwith 171 grams of iron per liter. The generatorsolution, however, can carry only 1 14i grams of iron per liter, which will enter into combination .with only 252 grains of sulfuricacid per liter. The generator solution therefore carries an excess of 18 grams of sulfuric acid per liter at the timesaid solution is saturated with iron, which'means that no further reaction will be possible unless the process is interrupted and water introduced to furnish sufficient liquid. to dissolve the iron capable of combining with the remaining 48 grams of sulfuric acid. This will cause a waste of gas. In accordance with the present invention, however, the acid solution is introduced at such astrength, say, in the example above given, 200 grams of sulfuric acid per liter, that the amount of iron capable of combining therewith will be easily retained in the generator solution at neutrality. In other words, in accordance with the present process, the acid is diluted to such a roportion that the total quantity of liquid is sufficient to retain in solution the product of the reaction when the acid in the said liquid is completely consumed.

From the gas outlet 17 the gas is conveyed to the treating or precipitating tank or chamber 26 in which the solution to be purified or, otherwise treated is placed. In the preferred arrangement shown the outlet 17 communicates with a pipe 27 leading to a separator 28in which any moisture carried by the is removed and from which leads a pipe 29 by which the gas is conveyed to a washer 30 from which said gas passes through a pipe 31 to said treating tank or chamber 26. At some point in the system is provided a pump or suction device whereby a circulation of gas is established and a condition of partial vacuum maintained in the generating drum 10, said device, as

herein shown, comprising a blower 32 in the piping 31. The pipe 31 communicates with the treating tank or chamber 26 at a point below the surface of. the liquid therein, but, for reasons hereinafter explained, preferably above the bottom thereof, through a suitable perforated inlet member 33. Said tank or chamber 26, which is fitted with a closed top, has superimposed thereon a. drum 34E communicating with the interior of the tank. The gas, after passing through the solution in the tank, enters the drum 34:, carrying with it the froth or foam formed by the action of the gas on the solution, said froth or foam being separated from the at.- tcnuated gas in said drum, and the SOllCl'PfLl ticles in suspension returning by gravity to the tank. Leading from' the separating drum 34 is a pipe 35 through which a portion of the attenuated or partially spent gas is returned to the generating chamber. or drum 10, where it is mixed with thefreshly generated gas and again conveyed to the treating tank. The pipe 35 preferably leads to a separator 46 in which the gas is relieved of any moisture takenup during its passage through the precipitating tank 26 and separating drum 34, and from which said gas passes through a pipe l? to the liquid inlet pipe 23 and thence to the drum 10 by way of the inlet 16. In this manner it will be seen that a closed circuit between the generating chamber and the treating chamber is provided, whereby the gas is used repeatedly in order to insure its complete exhaustion.

It has been observed that, when gas is introduced into a liquid, the greatest agitation of the liquid occurs a short distance above the level at which said gas is introduced, but since vigorous agitation isnecessary to the efficient treatment of solutions with hydrogen sulfid, it is desirable that the agitation be made as great as possible immediately adjacent the gas inlet. "To this end there is provided a second pipe 36 lead ing from the drum 34 to the bottom of the tank 26 where it communicates with a suitable perforated inlet member 37; said pipe 36 being provided with a blower or other circulating means 38, wherebya portion of the attenuated or partially spentgas'in the drum is returned to the tank 26. The attenuated gas which thus enters the treating tank below the inlet 33 produces, at a short distance above the inlet 37, and conse quently in the vicinity or zone of the inlet 33, a violent agitation. It will thus be seen that the richer. gas from the inlet 33 enters the solution at a point where violent agitation of the same occurs, which disperses said richer gas through. a, .very large volume of the solution, thereby insuring a relatively even treatment of the solution by the-gas. This is highly desirable, particularly inthe use'of hydrogen sulfid as purifying agent,

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since when said gas is introduced into the solution without additional agitation said solution is frequently locally overtreated.

For example, hydrogen sulfid'isfl frequently used forthe purpose of removin arsenic, copper, cadmium, and other impurities from A. the solutions of zinc sulfate. Overtreatment will resultin the removalqalso of a greater or less amount of zinc, which is object onable but diificult to avoid in apparatus as heretofore arranged and'in which the gas otherwise, means are preferably provided for automatically dischargingfrom the system any excess pressure developed therein, said means being of such a character as fully to utilize the gas discharged so as to prevent wastage thereof. As herein shown a third pipe 39 is led from the separating drum 34, said pipe being provided with a blower or other circulating means 40 and with a relief or check valve 41 adapted, when the pressure in the system exceeds a predetermined maximum, to open and per-- mit a portion of the attenuated gas in the separating drum 54 to be drawn through the pipe 39 by the blower 40. In order that the gas thus drawn through the pipe 39 may be completely utilized or exhausted, said gas may be forced by the blower "40 through a pipe 42 to a secondary or auxiliary precipitating or treating tank or chamber 43, said gas entering said tank or chamber through a suitable inlet 44, and being discharged to the atmosphere through a suit able exhaust pipe 45.

As a further safeguard against the development of pressure in the generating chamber 10, due to accidental obstruction of the system at some point, or otherwise, the separators 28 and 46 are preferably provided with water seals 50 and 51 adapted to be blown off in the event of excess pressure, thereby venting said pressure to the atmosphere. 7

The process above described is not claimed" herein but is claimed in my application No.

290,214, of which this case is a division.

Having thus described my invention I claim and desire to secure by Letters Patent:

1. The combination with a gas generator,

said inlet.

of a treating 'tankin closed circuit with said generator, and meansfor maintaining apartial vacuum 1n said generatori'fi Y combin'at'on'wih a gas generator ccompris'ing'a rotatabledrum having an axial inletand anlaxial outlet, of a closed treating tank, 'a pipe leading from said outlet to said tank, a1 1d apipeleading from saidtank to 3. The combination with a 5 gas generator,

of a closed treating tank, 'a pipe leading from said g'eneratorto said tank, a blower in saidpipa'a pipe le'ading'from said tank to a I.

said generator, and a relief valve adapted, I

when the'pressure in said system exceeds a predetermined maximum, to discharge therefrom a portion of the gas after its passage through said tank.

' 4. he combination witha gas generator, of a treating tank in closed circuit with said generator, meansfor maintaining a condition of partial vacuum in said generator and adjacent parts of the system, means for automatically discharging from the system a quantity of attenuated gas equal approximately to the amount of inward air leakage in said generator or other parts of" the system under partial vacuum, and an auxiliary treating tank through whichsaid dis- I charged gas is passed. I

5. The combination with a gas generator comprising a rotatabledrum having an axial inlet and an axial outlet, of a pipe communieating withsaid inlet for supplying a liquid 7, A

reagent to said drum, a closed treating tank,

a pipe leading from said outlet to said tank,

and a pipe leading from said tankand communicating with said liquid reagent supply a pipe.

fromdifi'erent sources. I s k 7. A treating tank having upper and'lower In an apparatus for treating liquids with gases, a treating tank having gas inlets disposed at different levels and means forsupplying to said inlets respectively gases gas inlets, means for supplyin freshv gas to said upper inlet, and means or conveyin attenuated gas fromthe upper part of sai tank to said lower inlet. c c

8. A treating tank having upper and lower gas inlets, means for supplying. fresh gas to 5 said upper inlet, and means for'forcmg an other gaseous mediumfinto sald lower inlet to cause agitation of the liquid in said tank in the vicinity of said upper inlet.

, 9. A treating tank having upperand lower gas'inlets, means for supplying fresh gas to c said upper inlet, a pipe leading from the upper part of said tank to said lowerinlet for supplying partially spent gases to said lower inlet, and a blower in said pipe.

10. A treating tank having upper and lower gas inlets, means for suppl ing fresh gas tosaid upper inlet, a gas and 0am separator superimposed upon said tankand communicating therewith, and .means or conveyingi attenuated gas, from said sepamtgr to said lower inlet. 7

'11. The corribinatipniyyith a: gas generator,

c se t e t ng .tam avi giupr ran rgas inlets, e n i0 1 supp yin ai upper' inlet wwith gas from ,saidl generator, means for returningv a p rqrti on of the. attenuated gas from the upper part of said; tank to said genergxtor, and. means jior, Qonye'ying another ,portlon of szud attenuated gas to ,saidl lower lnlet.

l2.l,The.qomb ination ith n gas generater,

of cbwdtmting tankhaving pp and fow i g n e nean r vslipplyi Sa pperl nl wi h. gas mm. m izi 'i enera o mee io r urnin @mrt ilthe at e afie gas i th upp nertoisa t nkt fromth System.

In testimony whereof Igflixmygignetnre.

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