US912340A - Process of handling the electrolytic products of brine in the treatment of fiber. - Google Patents

Description

W, V. WBNTWORTH & A. B. LARGHAR. PROOES$ 'or HANDLING THE ELECTROLYTIC PRODUQTSY 0F BRI-NE IN THE TREATMENT OF FIBER.

APPLIUATION FILED JAN.29, 1907.

Patented Feb. 16, 1909.

3 SHEETS-SHEET 1.

. W. V. WBNTWORTH & A. B. LAROHAR. PROCESS OF HANDLING THE BLEGTROLYTIG PRODUCTS 0F BRINE IN THE TREATMENT OF FIBER 1 mm 9 w W .M m a 1 Mb M T v m m w x s M a l M m I w m. e Z M 0 k v M W v .M 6 4; a 9 /J\ a n 3 m 3 D m. 2 E n Fw 2 P N 0 H o M n n I I 2 L n l/ O H w w A a m A m n a wank...i.5::a15:225:15: vxwwll /ia v f 5 1 un 0 4 4 9 u 3 .3 1 f 2 w. V. WENT W0R']3H 60A. B. LAROHAR. I PROCESS OF HANDLING THE ELEGTROLYTIG PRODUCTS 0F BBINB IN THE TREATMENT OF FIBER.

v .APPLIOATIONIILED JAN. 29, 1907.

912,340. Patented Feb. .16, 1909. I a ssnnnws-snm 3.

00000600000 25 H 88888888888 fissssa ssgs 23 l I Z6 I7 33 5] C u WW0; G WIN/14 \maAW/M%6,w

nth/AIM 351322, f f ,0" ap 10 i Heretofo're, caustic soda and ,chl'or'in produced 15 1905)hav e been'appli'ed, respective1y, to the .2 ytic -productsbetween the cell andItheir- "points of ap ""onefor-m of apparatus which may be'usezl to:

.45. separated from llatter; isigjpplied tothe fiber; r r We sTA PATENT-whamm- WALTER PEuoBsoo'r CHEMICAL FIBRE COM " rnocuss OF-IHAN-DLING- To all whom, it; may concern: f 3 Be itknown' that we,jWAL'rER V. Wnirr- WORTH and'AB'rnUn B. LARCHAR, "citizens of the UnitedStates', andresidents of Oldtown, county o f Penobs'cot, State of Maine, have.

invented ,a-new and useful- Improvement in. theProcesses of Handling the Electrolytic Products of Brine in the Treatment of Fiber, of which the following is a specification.

electrolysis of; brine (for example, i'nt e cell shown in U.v S. patents, to

,. f-August 25, 1903, and-793,138 dated June 27,

' separation "of cellulose fiber from wood and to the bleaching thereoti ,presjent mventmn constitutes an roved process' -of handling. said electroication to the fiber.

- In the a companying drawings is shown .carry into execution the process which is- :Flgure l'is a diagrammatic elevation of the apparatus comprised oursystem. Figs. 2, 3, 4 and 5 are detailsgofthe same. 1 1'- and 2 are two electrolytic cells which are referabl-y 0f the construction shown in said atents'793,l38 and. 736,982. .They are suplied with salt brine iromfiie tail; 3, whence it is forced 'by the pump 4 through the pipe 5,

v and the branch pipes-6 and 7 and valved nozchlorin gas product "of the electrolysis leaves the cells through the lazed tilepipe 10 and must be combined wit limeto form bleach before it is ap lied to the fiber. The causticwhich dis'char es into the storage tank 12.

Thiscaiustic 'so a eflluent generally consists of Y -about equal arts of caustic soda and un the caustic soda before the Specification. of Letters Paltezit. I 3 Application filed January. 29,1907. Serial No. 354,609.

1 funnel-shaped or hop v. wuurwoa'rn AND 'ARTHURY'B. LARGHAR, or OLDTOWN, MAINE,'AS SIG gas TO PANY, A CORPORATION OFV-IMAIN 1 Patented Felt-.16, i909.

er-shaped bottom 17. 4 The bank of steam tu es 18, slightly inclined from the horizontal, extends. across .fromside toside .of the shell 16, throu h which tubes 19 and 20. These steam tubes are so located as-to divide-the concentrator chamber into the uppenvapor space 21 and the-settling The portion that isnot vaporized flows down of tubes by the partition 25.

hopper. 17 and thence circulates up again continues until the desired concentration is reached and the strength of the circulation combined -with the continuous removal of the salt crystals as fast as formed preventthe scaling of the steam tubes. The valve 27 being open, the concentrated li'ubr set-' tles intothe receiving tank 28 (whic is, dur

pipe 30 connected by the pipe 31 with a source of compressed air normally shut off by thevalve 32 (Fig.1); I

33 is. he outlet pipe from through the openings inthe horizontal arti- I tion 26 among the tubes 18. 'lhis circu ation ing this operation, maintained under a vacu-' the receiver '28, p

steam is circulated between t e steam pipes space-'22-connected at one side ofthe bankof' 7c a forming vapor'in the chain er 21,whence. it escapes through any suitable opening as 24.

through the. assage 23 which is separated p from the ba It deposits a portionof its salt crystals in the near its bottom-with a perforated horizontal and 345the valve therein. This outlet ,pipe

' leads to the filter tank 35. When the liquorin the receiving tank-28 has reached the do:

desc "be separately the systems i forhandling the caustic s'ddaandthe chlorin,

resgectively, ontheir Way-to-thefiber. '50 a ndling the caustic soda.-..-The v combined fcausticsoda and brine-areaforced by the pump 13 .throu h thefpipe leinto a concen-- traitor lfiwhic isi'shown in detailin Figs. 4

sired concentration, 'the'valve 27 tempora rilyclosed, the valves 32 and 34 are-.-opene'g i and the compressed air blows the contentsfo'f the tank through the pipe 33 into thc filter tank 35. Ifcorn'pressed air is not available, as-pump! may from't ue-5. i'lms ma ts ofashell mm-va abe usedfor. forc'ingthe liquor; e'tank'2'8 ,tothe filter tank 35. t a i e additions- .--liquo'i has been T ereceivingtank evaporation which is proceeding a partly filling pumped into the concentrator 15 from the tank 12 and concentrated, the salt crystals the hopper so that as soon as the valve 27 is again opened, the crystals will wash-down into the tank 28, whereupon the valve 27 isagain closed and the receiver 28 emptied as before. In this way, normal operation, the process becomes substantially continuous since by opening the valve 27 at frequent intervals, the salt crystals accumulated in the hopper are intermittently withdrawn without sto )ping the l70V6. In

other words, the salt crystals accumulate in the downwardly extending hopper-shaped bottom below the zone of evaporation and can bepermitted to discharge periodically Without interfering with the evaporating process going on in the'zone of eva oration. The salt crystals with entraine caustic soda descending into the vacuum receiver 28 as above described, are in a viscous condition and the air by which they are blown from the vacuum receiver to the filter tank prevents the'consolidation of the viscous mass in the receiver 28 because it keeps the mass in a state of agitation as from the perforated above the mass which it must occu y for forcin the mass into the bottom out et 33. The fi ter tank contains above its bottom it passes in separate jets a perforated filter support 36 upon' which is supported'a layer 37,38 preferably of sand. the attempt be made to filter'the viscous mass of salt or stals and entrained caustic soda While stil retaining the heat of ,t11e

separator or evaporator 15, an excessive amount of salt is dissol ed; While if the partially drained mass of crystals is allowed to cool andis washed at a temperaturelow v enough to obviate this diificulty, it is liable to partially congeal so as to prevent the com- .pletion of the operation, and if pressure be applied to force it through the filter, such pressure will tend to force the finer salt crystals through with the caustic soda and possibly, also, particles of the filtering material itself. lVe have made the important discovery, among others, that these difliculties may be avoided by permitting the mass to cool as a preliminary to filtration. Putting this discovery into use and omitting thdpressure, but depending upon gravity for the filtration, we have found the operation to be entirely successful; the mass of salt crystals remaining comparatively loose and ungpnwo advantages are thus attained: (1) The cooling causes the se )aration of a larger percentage of salt crystals; and (2) when the salt crystals cool in the caustic solution, they form a loose mass and are much more easily Washed.

When, therefore, the iilter'tank 35 is being filled from the receiving chamber 28,1110

p1pe 30 to the. POSltIOD.

nected, respectively,

remain so until the mass has had as much time as practicable to cool, when the valve 40 islowed to filter through and drain into the until the efliuent shows the desired reedom from caustic. All of this dilute caustic soda is discharged through the pipe 43 into the tank 12, whence it again passes through the,

separator 15. The valve 41 is now closed and the valve 39 opened and the pure salt crystals remaining on the filter are dissolved by additions of hot water and run into the brine storage tank 44 from which itis raised by the pump 47 throughthe pipe 48 into the brine tank 3,. whence it is returned with additional brine, to the cells 1, 2 and the operation repeated. t at all the salt that escaped decomposition at the outset will be returned after being separated from its entrained caustic soda to the cells until it is completely decomposed, while the separated caustic soda accumulated in the tank 42 will be in a condition of purity enabling it to be applied to the fiber through the proper channels.

is a tank in which fresh salt cristals aredissolved to makebrine and whie is conwith the pipe 48 and tank 44 by the valved pipes 81 and 82.

It will thus be seen- Handling the ChZOT'iRFr' I hG chlorin gas leavin the cells throu h the pipe 10 proceeds throug the series ofa sorptlon towers 51, 52 and 53, each of which is composed of glazed tile. These towers are arran ed in series; the chlorin gas bein discharge( into the first one at the bottom rom the ipe 10, passin thence u ward through the tower an through t 1e pipe 54 downto the bottom of the next tower, thence. up through that tower and through the pipe 55 down to the bottom of the third tower, thence up throu h that tower to the outlet 56, which is umter the slight exhaust of a fan 57. Milk of lime is conveyed into the top of eachtower from the pipe 58 and in descending through each tower it meets the ascending current of chlorin and unites with it forming bleach or chlorid of lime. Each tower is provided with a perforated slate dashlate 58". arranged below the lime inlet an chlorin outlet sons to afford intimacy ofcontact between the lime and the chlorin. VlZhen the lime is fresh, most of the chlorin is absorbed in the first towerbut as the proportion of the towers.

' bleach increases andjthat of free lime decreases, more chlorin passes onto the secondtower and toward the end oi the operation some chlorin reaches the third tower, but only a trace ever. passes through this-thirdtower to the 0utlet56, if the apparatus is in proper working order.

59 and 60 are two milk ofhme tanks below 61 is a concrete trough ihto which all of the towers discharge 'their'liquid chlorid of lime at the bottom and from which trou h such liquid may be discharged'either into t tank .59 through the pipe 62, or into the tank 60 through the-pipe 63; the pi e not in use being closed by a suitable lug 64. Valved outlet pipes 65 and 66 lead from the bottom of each milk of lime tank to the pump 67 by which the milk of lime from the tank in use is pumped through the pipe 58 to the tops of the towers. An agitator 68 in each m1 lime tank keeps the lime in suspension While it is in operation. Each milk of lime tank is provided with a pivoted stand-pipe 69 connected with a valved outlet pipe 70 and controlled by a cord 71 so that the bleach or finished chloridi of lime can 'be drawn offfrom the tank to any depth desired. This bleach is .in proper condition to be aplied through suitable channels to the bleaching of the wood fiber.

In Fig 2 is shown a detail of the dash-' plate 58' and the lime-inlet-pipe 58 in one of the towers. In Fig.3, is shown a detail of the bottom of one or the towers and the chlorin-inlet-pipe 10 and of the liquid-outlet J pipe 61- into the concrete trough 61.

n operation, one of the milk of lime tanks will be-filled with milk of lime which will be circulated by the pump 67 over and over,

through the. absorption towers 51, 52, 53,

until it is all converted substantially into bleachi In the meantime, the other tank will 'be filled with milk of lime so that as soon as the conversion in the-tank 59 is complete, it can be cut oil from the towers and connection made with the tank 60. In this way, the absorption towers will be in substantially continuous operation; the two.

tanks 59 and 60 being alternately employed.

= From the foregoing description, it will be Patent:

The rocess of treatnu brine which con-q sists in electrolyzingthe same, then concentratmg the caustic soda effluent of the electrolysis, then cooling the concentrate and separating the same into its causticsoda and salt constituents.

- In testimony whereof, we have hereunto signed our names in the presence of two subscribing witnesses.

WALTER V. VVENTWORTH. V v ARTHUR B. LARCHAR. Witnesses;

Jos. F. GOULD, CLARA. H. GOULD.

Images