US3194638A - Combined slaker-causticizer apparatus - Google Patents
Combined slaker-causticizer apparatus Download PDFInfo
- Publication number
- US3194638A US3194638A US239118A US23911862A US3194638A US 3194638 A US3194638 A US 3194638A US 239118 A US239118 A US 239118A US 23911862 A US23911862 A US 23911862A US 3194638 A US3194638 A US 3194638A
- Authority
- US
- United States
- Prior art keywords
- vessel
- compartment
- liquor
- slaker
- causticizer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000004891 communication Methods 0.000 claims description 3
- 238000009993 causticizing Methods 0.000 description 19
- 238000006243 chemical reaction Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 14
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 13
- 235000011941 Tilia x europaea Nutrition 0.000 description 13
- 239000004571 lime Substances 0.000 description 13
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 11
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 238000010411 cooking Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 239000000292 calcium oxide Substances 0.000 description 5
- 235000012255 calcium oxide Nutrition 0.000 description 5
- 238000004537 pulping Methods 0.000 description 4
- 229910000029 sodium carbonate Inorganic materials 0.000 description 4
- 239000002585 base Substances 0.000 description 3
- 239000011362 coarse particle Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 241000290143 Pyrus x bretschneideri Species 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 235000011116 calcium hydroxide Nutrition 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 241001062472 Stokellia anisodon Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
- C01D1/04—Hydroxides
- C01D1/20—Preparation by reacting oxides or hydroxides with alkali metal salts
- C01D1/22—Preparation by reacting oxides or hydroxides with alkali metal salts with carbonates or bicarbonates
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/0064—Aspects concerning the production and the treatment of green and white liquors, e.g. causticizing green liquor
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/40—Production or processing of lime, e.g. limestone regeneration of lime in pulp and sugar mills
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S423/00—Chemistry of inorganic compounds
- Y10S423/03—Papermaking liquor
Definitions
- the rst step in recovering these compounds is to lirst concentrate and then burn the spent cooking liquor.
- the smelt obtained isthen dissolved to form what is known as green liquor.
- the Vgreen liquor is essentially a solution of sodiumA carbonate, while in the sulfate process, the green liquor also contains sodium sulphide.
- the next step in recovery is to causticize the green liquor by the addition of quicklime (CaO) to thereby convert the sodium carbonate to sodium hydroxide and produce white liquor suitable for reuse in the cooking process.
- the degritted slurry overows from the claker-classiiier into a level-controlled headbox and is pumped from there through a series of tanks in which it is agitated, and the causticizing reaction, already started in the slarker, is completed.
- the causticized slurry then passes to a clarifier where the precipitated lime mud is separated out and is usually pumped to a thickener for recovery.
- the strong white liquor removed from the clariiier is then ready for use in cooking.
- a serious disadvantage of the conventional slakingcausticizing system is the tendency for portions of the reacting slurry to overflow from one stage to the next without being retained in a particular reaction zone for the full time intended.
- This short-circuiting or bypassing of relatively unreacted chemicals is relatively ineicient and does not utilize the available chemicals to the best advantage.
- a further object is to provide an improved and more efficient method for carrying out the slaking-causticizing operation, utilizing the improved apparatus to insure against short-circuiting or bypassing of relatively unreacted chemicals.
- FIG. 1 is a sectional elevational one embodiment of a combined slaker-causticizer constructed in accordance with this invention and employed in carrying out the improved process.
- FIG. 2 is a perspective view showing in more detail the vertical and horizontal baffle structure in the apparatus.
- FIG. 3 is a perspective view showing the details of a preferred structure for the agitator mechanism in the apparatus.
- FIG. 4 is a perspective View showing in more detail annular seal plates comprising a part of the apparatus structure.
- a preferred embodiment of the combined slaker-causticizer tower comprises a closed vertical cylindrical vessel Ell divided into a top slaking compartment l2, and three causticizing compartments i3, 14 and l5, by hat horizontal floor elements in the form of annular stator baliles le, 17 and 1S suitable supported and mounted therein and provided with annular seal plates 23 extending to the interior lining 48 of vessel 1l.
- These annular baffles are imperforate except for large central circular apertures l5", 2t? and 2l.
- Aperture i9 in baiie le which separates slaking compartment i2 from the first causticizing compartment i3, is preferably flanged upwardly as at Z2 to provide baille 16 with an annular vertical portion. Apertures 26 and 2l do not have such auxiliary central flange.
- the annular baffles are rigidiiied and partially supported by vertical adjuctions 5d extending through each compartment for the full height of the vessel and spaced at intervals.
- the vertical batiles Sti are normally spaced from the interior lining 48 of the vessel to avoid dead areas. it is also understood that more vertical bailies than the number shown in the drawing may be provided.
- Top plate 2d of vessel l1 is provided with a diametrically extending mounting plate 25 carrying an electric motor 26 coupled to a central vertical shaft 27 extending vertically and axially of vessel 1l.
- Shaft 27 is rotatably mounted in bearing 28 on the floor of the vessel, and is provided with a seal 32 where it enters the tower.
- Shaft Z7 has fixed thereon a plurality of rotor bailes in the form of fiat, circular impertorate discs 29, Sti, Eil and agitators 33, 34, 35, and 36.
- Rotor baiiie 29 and agitator 33 are shown in this embodiment to be of unitary construction, while the remaining agitators and rotor battles are in spaced arrangement.
- Bale Z9 and agitator 33 may also oe in spaced arrangement, if desired.
- the rotor batiies are suitably sapced from their respective stator bailies to restrict the passage therethrough of iiuid being treated to prevent intermixing or short circuiting between compartments.
- a typical annular spacing is about l", but it may be varied to suit particular conditions.
- Top plate 24 is provided with a lime feed aperture 37 and an inlet pipe 38 for green liquor.
- the top plate also is equipped with a vent 39 andan access manhole di).
- Cylinder wall 41 in kslaking compartment l2 is provided with a flanged overow outlet 42 connected to the sewer or a suitable collecting vessel.
- a grit withdrawal outlet 43 is also provided in cylinder wall il near the base of slaking compartment l2.
- the cylinder wall in each of the causticizing compartments is provided with llanged discharge or cleanout outlets 4d, 45 and 46 near the base of each compartment with the latter outlet 46 also serving as the conduit for discharging fully causticized white liquor.
- An inspection manhole 47 may also be provided in the lowermost caustisizing compartment l5.
- Those parts of structure which come into contact with the chemical slurry are preferably made of stainless steel or other erosion or corrosion-resistant material.
- the walls and bottom of cylinder 11 may be suitable lined with alkali-resistant brick 48, as shown, if the more expensive stainless steel is not employed for the cylinder wall structure.
- strong green liquor is introduced through inlet 38, and a measured dow of quicktime, either reclaimed lime sludge or fresh lime, is introducedtbrough lime feed aperture 37, while rotor shaft 27, agitator 33 .and ⁇ rotor baille 29 are turned at a speed sullicient'to provide circulation and intimate intermixing of the chemical slurry to assist in the ini-tial slaking reaction while maintaining undissolved materia-ls inV uniform suspension.
- Rotor baille 29 is closely spaced from annular ilange or dam 22 of stator baflle 16 to restrict flow from the slaking compartment l2 into the rst causticizing compartment 13 thus preventing undesirable short-circuiting,
- the annular flange 22 further serves to retain in slaking compartment l2 large grit particles and unreacted material which settles outfor subsequent removal through grit withdrawal outlet 43 suitably equipped with a gate valve or the like.
- Centrifugal action of the agitator 33 and rotor baille 29 also tends to ⁇ direct the undesirable coarse particles of grits and unreacted material in the slurry to the periphery of stator baille 16 from where the particles are removed by continuously or intermittently withdrawing a portion of the slurry through outlet 43 by means or" a suitable exterior pump, not shown.
- the withdrawn portion of the liquor containing the grits is subsequently screened, the grits discarded, and 4the degritted liquor returned to the yslaking compartment.
- the degritted liquor may 'be returned through vent 39 thereby serving as a wash for fumes and dust being vented therethrough.
- the reacted liquor in the slaking compartment llows into the rst causticizing compartment through the -restricted annular .aperture formed by closely spaced rotor baille 29 and dam 22. Such spacing may be adjusted as desired, but a 'spacing of about 1" was found to work satisfactorily.
- the flow continues to each of the causticizing compartments in sequence through the restricted lannular apertures shown, and substantiallyk fully reacted and causticized white liquor is removed continuously through discharge conduit 46. After claricat-ion to remove lime mud, the clarified causticized liquor is ready for use in the pulping operation.
- Thelime mud removed in the clarifying step is washed, thickened and reburnt to convert it to CaO, for subsequent reuse in the slaking-causticizing operation.
- the size of the vessel and each compartment is such that total retention time of the liquor is suillcient to obtain optimum reaction for each stage of the process. For example, about l minutes in the slaking compartment, and a total of about 2 hours in the causticizing section is suillcient to bring the reaction to substantial completeness.
- the causticizing section is compartmented and ⁇ connected by restricted openings as shown, to prevent short-circuiting between reaction zones, and insuresagainst intermixing of less reacted material with more completely reactedmaterial.
- the number and size of the individual causticizing compartments may be varied to suit particular conditions, depending on-total capaoity designed int-o equipment, rate of ilow, andthe like.
- the vessel In startup operation, the vessel is first lilled with green liquor to operating level 49 before lime is introduced. A major portion of the green liquor used in initial filling is substantially unreacted and may be shunted back to the green liquor feed until acceptable ful-l strength white liquor is obtained at the discharge end.
- the apparatus Iand method described in this invention make possible more complete mXIlg, better temperature control, a simpler Vllow pattern, all combining to produce a more uniform liquor than vwas hitherto possible and at substantial savings in cost.
- a combined slaker-causticizer .apparatus comprising a vertical cylindricalvessel, a *pluralityy of spaced ⁇ stationary horizontal imperforate batlles dividing said vessel into superposed compartments, said baflles having central apertures therein for communication between said con1- par-tments, an upstanding iiange disposed around the circumference of :the central aperture in theV uppermost compartment,
- a combined slaker-causticizer apparatus comprising a vertical cylindrical vessel, a plurality of horizontal annular stator imperforate baffles :axially spaced in said vessel to divide said vessel into a plurality of superp-osed reaction chambers, said baflles having centrally disposed circular apertures therein dening communicationcha'nnels'between said chambers, an upwardly extending liange coextensive with the circularfa-perture in thefloor of the uppermost chamber, a plurality of annularly spaced stationary vertical baillesextending radially inward from the outer peripheryof said horizontal batlles, av rotatably mounted shaft extending axially of said vessel, a plurality of ilat horizontal circular rotor imperforate battles mounted on said shaft and closely spaced above each of said apertures to partially' Irestrict communication between said chambers, agitator means mounted on said shaft for rotation in each of said chambers, inlet means above the uppermost chamber for admitting a reactive u
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Paper (AREA)
Description
July 13, 1965 s. M. NEUVILLE 3,194,638
COMBINED sLAxER-CAUSTICIZER APPARATUS Filed Nov. 21. 1962 2 Sheets-Sheet 1 July 13, 1965 s. M. NEUVILLE COMBINED SLAKER-CAUSTICIZER APPARATUS 2 Sheets-Sheet 2 Filed NOV. 2l. 1962 Flc. 2
United States Patent O @$4,638 COMBINED SLAKER-CAUSTHCZER APPARATUS Stewart M. Neuville, Harrison, Wis., assigner to Kimnearly-Clark Corporation, Neenah, Wis., a corporation oi' Delaware Filed Nov. Z1, i962, Ser. No. 239,118 2 Claims. (Cl. 2.3-2S3) This applicationv relates to an improved method and apparatus for the preparation of cooking liquor in the alkaline pulping of cellulosic materials. More specically it relates to a combined lime slaker and causticizer and an improved more ecient method for preparing white liquor for use in. alkaline pulping.
Economic operating of the alkaline pulping process requires the recovery and reuse of the chemicals employed in cooking the cellulosic source material. The rst step in recovering these compounds is to lirst concentrate and then burn the spent cooking liquor. The smelt obtained isthen dissolved to form what is known as green liquor. In the soda process, the Vgreen liquor is essentially a solution of sodiumA carbonate, while in the sulfate process, the green liquor also contains sodium sulphide. The next step in recovery is to causticize the green liquor by the addition of quicklime (CaO) to thereby convert the sodium carbonate to sodium hydroxide and produce white liquor suitable for reuse in the cooking process.
In conventional operations, slaking of the lime and subsequent causticization of the green liquor is done in separate units, each specially designed to carry out a ingle step of the process. Thus, strong green liquor is fed to a lime slaker-classier unit where it is mixed with and slakes a measured liow of quicklime. The resultant milk of lime ows to a classier sectionv for removal of coarse grit and unreacted material by means of a conveyor or rake-like device moving up the inclined bottom of the classifier tank. The degritted slurry overows from the claker-classiiier into a level-controlled headbox and is pumped from there through a series of tanks in which it is agitated, and the causticizing reaction, already started in the slarker, is completed. The causticized slurry then passes to a clarifier where the precipitated lime mud is separated out and is usually pumped to a thickener for recovery. The strong white liquor removed from the clariiier is then ready for use in cooking.
A serious disadavantage of the conventional slakingcausticizing system is the tendency for portions of the reacting slurry to overflow from one stage to the next without being retained in a particular reaction zone for the full time intended. This short-circuiting or bypassing of relatively unreacted chemicals is relatively ineicient and does not utilize the available chemicals to the best advantage. l
It is an object of this invention to combine the slaking and causticizing operation in a single unit thus providing savings in both equipment and space requirements.
A further obiect is to provide an improved and more efficient method for carrying out the slaking-causticizing operation, utilizing the improved apparatus to insure against short-circuiting or bypassing of relatively unreacted chemicals.
. Additional objects and advantages of the invention will become apparent from the following detailed description of certain preferred embodiments together with the accompanying drawing.
In the drawings, e
FIG. 1 is a sectional elevational one embodiment of a combined slaker-causticizer constructed in accordance with this invention and employed in carrying out the improved process.
ICC
FIG. 2 is a perspective view showing in more detail the vertical and horizontal baffle structure in the apparatus.
FIG. 3 is a perspective view showing the details of a preferred structure for the agitator mechanism in the apparatus.
FIG. 4 is a perspective View showing in more detail annular seal plates comprising a part of the apparatus structure.
In accordance with the invention, the primary object is attained by arranging slaking and causticizing units in a single vertical tower. As shown in the drawings, a preferred embodiment of the combined slaker-causticizer tower comprises a closed vertical cylindrical vessel Ell divided into a top slaking compartment l2, and three causticizing compartments i3, 14 and l5, by hat horizontal floor elements in the form of annular stator baliles le, 17 and 1S suitable supported and mounted therein and provided with annular seal plates 23 extending to the interior lining 48 of vessel 1l.. These annular baffles are imperforate except for large central circular apertures l5", 2t? and 2l. Aperture i9 in baiie le, which separates slaking compartment i2 from the first causticizing compartment i3, is preferably flanged upwardly as at Z2 to provide baille 16 with an annular vertical portion. Apertures 26 and 2l do not have such auxiliary central flange. The annular baffles are rigidiiied and partially supported by vertical baies 5d extending through each compartment for the full height of the vessel and spaced at intervals. The vertical batiles Sti are normally spaced from the interior lining 48 of the vessel to avoid dead areas. it is also understood that more vertical bailies than the number shown in the drawing may be provided.
Top plate 2d of vessel l1 is provided with a diametrically extending mounting plate 25 carrying an electric motor 26 coupled to a central vertical shaft 27 extending vertically and axially of vessel 1l. Shaft 27 is rotatably mounted in bearing 28 on the floor of the vessel, and is provided with a seal 32 where it enters the tower. Shaft Z7 has fixed thereon a plurality of rotor bailes in the form of fiat, circular impertorate discs 29, Sti, Eil and agitators 33, 34, 35, and 36. Rotor baiiie 29 and agitator 33 are shown in this embodiment to be of unitary construction, while the remaining agitators and rotor battles are in spaced arrangement. Bale Z9 and agitator 33 may also oe in spaced arrangement, if desired. The rotor batiies are suitably sapced from their respective stator bailies to restrict the passage therethrough of iiuid being treated to prevent intermixing or short circuiting between compartments. A typical annular spacing is about l", but it may be varied to suit particular conditions. Top plate 24 is provided with a lime feed aperture 37 and an inlet pipe 38 for green liquor. The top plate also is equipped with a vent 39 andan access manhole di). Cylinder wall 41 in kslaking compartment l2 is provided with a flanged overow outlet 42 connected to the sewer or a suitable collecting vessel. A grit withdrawal outlet 43 is also provided in cylinder wall il near the base of slaking compartment l2. The cylinder wall in each of the causticizing compartments is provided with llanged discharge or cleanout outlets 4d, 45 and 46 near the base of each compartment with the latter outlet 46 also serving as the conduit for discharging fully causticized white liquor. An inspection manhole 47 may also be provided in the lowermost caustisizing compartment l5. Those parts of structure which come into contact with the chemical slurry are preferably made of stainless steel or other erosion or corrosion-resistant material. For example, the walls and bottom of cylinder 11 may be suitable lined with alkali-resistant brick 48, as shown, if the more expensive stainless steel is not employed for the cylinder wall structure.
In operation, strong green liquor is introduced through inlet 38, and a measured dow of quicktime, either reclaimed lime sludge or fresh lime, is introducedtbrough lime feed aperture 37, while rotor shaft 27, agitator 33 .and `rotor baille 29 are turned at a speed sullicient'to provide circulation and intimate intermixing of the chemical slurry to assist in the ini-tial slaking reaction while maintaining undissolved materia-ls inV uniform suspension. Rotor baille 29 is closely spaced from annular ilange or dam 22 of stator baflle 16 to restrict flow from the slaking compartment l2 into the rst causticizing compartment 13 thus preventing undesirable short-circuiting, The annular flange 22 further serves to retain in slaking compartment l2 large grit particles and unreacted material which settles outfor subsequent removal through grit withdrawal outlet 43 suitably equipped with a gate valve or the like. Centrifugal action of the agitator 33 and rotor baille 29 also tends to `direct the undesirable coarse particles of grits and unreacted material in the slurry to the periphery of stator baille 16 from where the particles are removed by continuously or intermittently withdrawing a portion of the slurry through outlet 43 by means or" a suitable exterior pump, not shown. The withdrawn portion of the liquor containing the grits is subsequently screened, the grits discarded, and 4the degritted liquor returned to the yslaking compartment. The degritted liquor may 'be returned through vent 39 thereby serving as a wash for fumes and dust being vented therethrough. The reacted liquor in the slaking compartment llows into the rst causticizing compartment through the -restricted annular .aperture formed by closely spaced rotor baille 29 and dam 22. Such spacing may be adjusted as desired, but a 'spacing of about 1" was found to work satisfactorily. The flow continues to each of the causticizing compartments in sequence through the restricted lannular apertures shown, and substantiallyk fully reacted and causticized white liquor is removed continuously through discharge conduit 46. After claricat-ion to remove lime mud, the clarified causticized liquor is ready for use in the pulping operation. Thelime mud removed in the clarifying step is washed, thickened and reburnt to convert it to CaO, for subsequent reuse in the slaking-causticizing operation.
The size of the vessel and each compartment is such that total retention time of the liquor is suillcient to obtain optimum reaction for each stage of the process. For example, about l minutes in the slaking compartment, and a total of about 2 hours in the causticizing section is suillcient to bring the reaction to substantial completeness. The causticizing section is compartmented and `connected by restricted openings as shown, to prevent short-circuiting between reaction zones, and insuresagainst intermixing of less reacted material with more completely reactedmaterial. The number and size of the individual causticizing compartments may be varied to suit particular conditions, depending on-total capaoity designed int-o equipment, rate of ilow, andthe like.
In startup operation, the vessel is first lilled with green liquor to operating level 49 before lime is introduced. A major portion of the green liquor used in initial filling is substantially unreacted and may be shunted back to the green liquor feed until acceptable ful-l strength white liquor is obtained at the discharge end.
While this specific example relates to reconstituting green liquor derived from spent alkaline cooking liquor, the process ,and apparatus is equally applicable to the preparation of fresh cooking liquor from unslaked lime and fresh sodium carbonate solution.
The chemical reaction involved in the slaking-causticizing operation is well known and proceeds in two stages. In the first, or slaking, stage, calcium oxide (CaO) lof the lime llrst reacts with the water in the green lliquorto form calcium hydroxide (Ca(OH)2) with thek evolution of considerable heat.l This reaction may be written as follows.
The resultant calcium hydroxide then reacts with the sodium carbonate in the green-liquor to form sodium hydroxide and calcium carbonate precipitate. This causticizing reaction may be written:l
Although written in two stages, the reactions actually overlap, and par-t of the causticizing -occurs almost simultaneously with the slaking. The reaction is reversible to some extent, and lall the sodium carbonate 4cannot be converted to sodium hydroxide no mater how much lime is used.- Howevenfthe use of hot fresh lime, high temperature, and intimate mixing tall aid in improving ellioiency. It is underst'oodVthat means may be provided for regulating temperature of the reaction at its optimum level.
The apparatus Iand method described in this invention make possible more complete mXIlg, better temperature control, a simpler Vllow pattern, all combining to produce a more uniform liquor than vwas hitherto possible and at substantial savings in cost.
When the slaking-causticizing operation is carried out in the apparatus shown and by the method described, several advantages result. The unitary construction is more economical, utilization of Vgravity llow requires less complicated and expensiveauxiliary equipment, and reten- -tion time is more easily controlled thus permitting more complete causticizing and `better overall efficiency.
It will be understood that various changes in fthe process details and arrangements of parts herein described and 4illustrated for the purpose of'explaining the invention may be made by those skilled in the art within the principles and scope of the invention las defined in the appended claim-s.
What is `claimed is: Y 1. A combined slaker-causticizer .apparatus comprising a vertical cylindricalvessel, a *pluralityy of spaced `stationary horizontal imperforate batlles dividing said vessel into superposed compartments, said baflles having central apertures therein for communication between said con1- par-tments, an upstanding iiange disposed around the circumference of :the central aperture in theV uppermost compartment, |a shaft rotatably mounted axially of said vessel and extending through said compartments, hor-izontal rotating imperforate batlles mounted on said shaft adjacent to and closely vspaced from each rof said apertures, agitating means located in each compartment and mounted on said shaft, means forgadrnitting both dry and liquid reaction chemicals into the uppermost of said cornpartments for mixture therein, outlet means near the door of said uppermost compartment and communicating with an exterior of the vessel for withdrawing from the uppermost compartment a portion of the reaction mixture containing coarse particles, and youtlet means at the base of the l'owermost compartment of said vessel-for removing fully reacted chemicals. Y
2. A combined slaker-causticizer apparatus comprising a vertical cylindrical vessel, a plurality of horizontal annular stator imperforate baffles :axially spaced in said vessel to divide said vessel into a plurality of superp-osed reaction chambers, said baflles having centrally disposed circular apertures therein dening communicationcha'nnels'between said chambers, an upwardly extending liange coextensive with the circularfa-perture in thefloor of the uppermost chamber, a plurality of annularly spaced stationary vertical baillesextending radially inward from the outer peripheryof said horizontal batlles, av rotatably mounted shaft extending axially of said vessel, a plurality of ilat horizontal circular rotor imperforate battles mounted on said shaft and closely spaced above each of said apertures to partially' Irestrict communication between said chambers, agitator means mounted on said shaft for rotation in each of said chambers, inlet means above the uppermost chamber for admitting a reactive uid `chemical therein, a second inlet means `above said uppermost chamber for admitting a reactive solid chemical therein, outlet means near the oor of said uppermost chamber and communicating with the exterior of the vessel for withdrawing a portion of the reaction mixture containing coarse particles from said chamber, and outlet mea-ns near the oor of the lowermost chamber for withdrawing fully reacted chemica-ls.
References Cited by the Examiner UNITED STATES PATENTS Zellweger 259-66 Moore et al. 23-133 Robinson et a1. 259-66 Knight 162-30 Walker 23-185 Samaniego et al. 259-108 10 MORRIS o. woLK, Primary Examiner.
WILLIAM B. KNIGHT, Examiner.
Claims (1)
1. A COMBINED SLAKER-CAUSTICIZER APPARATUS COMPRISING A VERTICAL CYLINDRICAL VESSEL, A PLURALITY OF SPACED STATIONARY HORIZONTAL IMPERFORATE BAFFLES DIVIDING SAID VESSEL INTO SUPERPOSED COMPARTMENTS, SAID BAFFLES HAVING CENTRAL APERTURES THEREIN FOR COMMUNICATION BETWEEN SAID COMPARTMENTS, AN UPSTANDING FLANGE DISPOSED AROUND THE CIRCUMFERENCE OF THE CENTRAL APERTURE IN THE UPPERMOST COMPARTMENT, A SHAFT ROTATABLY MOUNTED AXIALLY OF SAID VESSEL AND EXTENDING THROUGH SAID COMPARTMENTS, HORIZONTAL ROTATING IMPERFORATE BAFFLES MOUNTED ON SAID SHAFT ADJACENT TO AND CLOSELY SPACED FROM EACH OF SAID APERTURES, AGITATING MEANS LOCATED IN EACH COMPARTMENT AND
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US239118A US3194638A (en) | 1962-11-21 | 1962-11-21 | Combined slaker-causticizer apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US239118A US3194638A (en) | 1962-11-21 | 1962-11-21 | Combined slaker-causticizer apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3194638A true US3194638A (en) | 1965-07-13 |
Family
ID=22900692
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US239118A Expired - Lifetime US3194638A (en) | 1962-11-21 | 1962-11-21 | Combined slaker-causticizer apparatus |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3194638A (en) |
Cited By (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3269941A (en) * | 1964-03-23 | 1966-08-30 | Kimberly Clark Co | Method of neutralizing acid bleachery effluent |
| US3363994A (en) * | 1966-06-21 | 1968-01-16 | Chemithon Corp | Chemical digester |
| US3408051A (en) * | 1966-02-23 | 1968-10-29 | Mixing Equipment Co Inc | Column mixing apparatus |
| US3495808A (en) * | 1967-08-29 | 1970-02-17 | Owens Corning Fiberglass Corp | Automatic binder mix system |
| US3664506A (en) * | 1968-12-03 | 1972-05-23 | Sertna Soc D Etudes Et De Rech | Apparatus for purifying blood |
| US3718973A (en) * | 1970-05-01 | 1973-03-06 | R Slater | Dental system |
| US3807703A (en) * | 1972-10-12 | 1974-04-30 | Usm Corp | Mixer-emulsators |
| US3977655A (en) * | 1973-04-21 | 1976-08-31 | Sybron Corporation | Liquid agitator with vibration suppressing stabilizers |
| US4333910A (en) * | 1980-01-31 | 1982-06-08 | Krupp-Koppers Gmbh | Arrangement for discharging coke from a cooling shaft supplied with cooling gas |
| US4389376A (en) * | 1979-03-28 | 1983-06-21 | Sadao Kojima | Apparatus for the preparation of slaked lime solution |
| US4400219A (en) * | 1980-10-31 | 1983-08-23 | Graanderivatan Raffinaderijen Amylum, In Het Kort: G.R. Amylum, Vroeger Glucose Ries Reunies Genoemd | Plant for continuously preparing starch glue |
| US4416424A (en) * | 1978-08-14 | 1983-11-22 | Conoco Inc. | Method and apparatus for deashing coal liquefaction effluents |
| US4521349A (en) * | 1983-01-20 | 1985-06-04 | A. R. Wilfley And Sons, Inc. | Fluid diffuser for gases and liquids |
| US4610547A (en) * | 1984-07-30 | 1986-09-09 | Canadian Patents And Development Limited | Particulate material in a liquid |
| US4627888A (en) * | 1983-02-23 | 1986-12-09 | Enso-Gutzeit Oy | Causticizing method |
| US4666690A (en) * | 1985-12-20 | 1987-05-19 | Foster Wheeler Development Corporation | Method for removing sulfur dioxide from flue gases |
| US4668342A (en) * | 1985-12-03 | 1987-05-26 | Canadian Patents And Development Ltd. | Recausticizing kraft green liquor |
| US4762590A (en) * | 1985-03-19 | 1988-08-09 | Enso-Gutzeit Oy | Causticizing process |
| US5145556A (en) * | 1991-07-31 | 1992-09-08 | International Paper Company | Single-stage slaking and causticizing method |
| US5294408A (en) * | 1993-04-16 | 1994-03-15 | Dravo Lime Company | Compact lime slaker |
| US5368731A (en) * | 1993-10-04 | 1994-11-29 | Dorr-Oliver Incorporated | Vacuum assisted slaker classifier |
| US5728893A (en) * | 1995-12-06 | 1998-03-17 | Union Carbide Chemicals & Plastics Technology Corporation | Process using multistaged reactors |
| US6024481A (en) * | 1994-10-25 | 2000-02-15 | Alfa Laval Ab | Mixer for mixing of liquids or suspensions and method for mixing |
| WO2000068496A1 (en) * | 1999-05-07 | 2000-11-16 | Kvaerner Pulping Ab | Feeding device and process and feeding system which utilise the feeding device |
| US20080025143A1 (en) * | 2004-09-15 | 2008-01-31 | Hiroaki Ohashi | Apparatus and Method for Solid-Liquid Contact |
| US20160121276A1 (en) * | 2014-10-31 | 2016-05-05 | Quantum Technologies, Inc. | Dynamic mixing assembly with improved baffle design |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US679587A (en) * | 1899-09-26 | 1901-07-30 | John Zellweger | Apparatus for collecting gases, vapors, and foreign particles from air. |
| US1099565A (en) * | 1913-12-31 | 1914-06-09 | Hugh K Moore | Method of making sulfite liquor. |
| US1776325A (en) * | 1927-10-06 | 1930-09-23 | Gypsum Lime And Alabastine Can | Method of making cellular wall board |
| US2552183A (en) * | 1945-04-07 | 1951-05-08 | Dorr Co | Two-stage causticizing |
| US2560016A (en) * | 1948-01-05 | 1951-07-10 | Traylor Engineering & Mfg Comp | Method of and means for producing milk of lime and for causticizing green liquor |
| US3013866A (en) * | 1959-07-29 | 1961-12-19 | Shell Oil Co | Fluid mixer with rotating baffles |
-
1962
- 1962-11-21 US US239118A patent/US3194638A/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US679587A (en) * | 1899-09-26 | 1901-07-30 | John Zellweger | Apparatus for collecting gases, vapors, and foreign particles from air. |
| US1099565A (en) * | 1913-12-31 | 1914-06-09 | Hugh K Moore | Method of making sulfite liquor. |
| US1776325A (en) * | 1927-10-06 | 1930-09-23 | Gypsum Lime And Alabastine Can | Method of making cellular wall board |
| US2552183A (en) * | 1945-04-07 | 1951-05-08 | Dorr Co | Two-stage causticizing |
| US2560016A (en) * | 1948-01-05 | 1951-07-10 | Traylor Engineering & Mfg Comp | Method of and means for producing milk of lime and for causticizing green liquor |
| US3013866A (en) * | 1959-07-29 | 1961-12-19 | Shell Oil Co | Fluid mixer with rotating baffles |
Cited By (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3269941A (en) * | 1964-03-23 | 1966-08-30 | Kimberly Clark Co | Method of neutralizing acid bleachery effluent |
| US3408051A (en) * | 1966-02-23 | 1968-10-29 | Mixing Equipment Co Inc | Column mixing apparatus |
| US3363994A (en) * | 1966-06-21 | 1968-01-16 | Chemithon Corp | Chemical digester |
| US3495808A (en) * | 1967-08-29 | 1970-02-17 | Owens Corning Fiberglass Corp | Automatic binder mix system |
| US3664506A (en) * | 1968-12-03 | 1972-05-23 | Sertna Soc D Etudes Et De Rech | Apparatus for purifying blood |
| US3718973A (en) * | 1970-05-01 | 1973-03-06 | R Slater | Dental system |
| US3807703A (en) * | 1972-10-12 | 1974-04-30 | Usm Corp | Mixer-emulsators |
| FR2202719A1 (en) * | 1972-10-12 | 1974-05-10 | Usm Corp | |
| US3977655A (en) * | 1973-04-21 | 1976-08-31 | Sybron Corporation | Liquid agitator with vibration suppressing stabilizers |
| US4416424A (en) * | 1978-08-14 | 1983-11-22 | Conoco Inc. | Method and apparatus for deashing coal liquefaction effluents |
| US4389376A (en) * | 1979-03-28 | 1983-06-21 | Sadao Kojima | Apparatus for the preparation of slaked lime solution |
| US4333910A (en) * | 1980-01-31 | 1982-06-08 | Krupp-Koppers Gmbh | Arrangement for discharging coke from a cooling shaft supplied with cooling gas |
| US4400219A (en) * | 1980-10-31 | 1983-08-23 | Graanderivatan Raffinaderijen Amylum, In Het Kort: G.R. Amylum, Vroeger Glucose Ries Reunies Genoemd | Plant for continuously preparing starch glue |
| US4521349A (en) * | 1983-01-20 | 1985-06-04 | A. R. Wilfley And Sons, Inc. | Fluid diffuser for gases and liquids |
| US4627888A (en) * | 1983-02-23 | 1986-12-09 | Enso-Gutzeit Oy | Causticizing method |
| US4610547A (en) * | 1984-07-30 | 1986-09-09 | Canadian Patents And Development Limited | Particulate material in a liquid |
| US4762590A (en) * | 1985-03-19 | 1988-08-09 | Enso-Gutzeit Oy | Causticizing process |
| US4668342A (en) * | 1985-12-03 | 1987-05-26 | Canadian Patents And Development Ltd. | Recausticizing kraft green liquor |
| US4666690A (en) * | 1985-12-20 | 1987-05-19 | Foster Wheeler Development Corporation | Method for removing sulfur dioxide from flue gases |
| US5145556A (en) * | 1991-07-31 | 1992-09-08 | International Paper Company | Single-stage slaking and causticizing method |
| US5294408A (en) * | 1993-04-16 | 1994-03-15 | Dravo Lime Company | Compact lime slaker |
| US5368731A (en) * | 1993-10-04 | 1994-11-29 | Dorr-Oliver Incorporated | Vacuum assisted slaker classifier |
| US6024481A (en) * | 1994-10-25 | 2000-02-15 | Alfa Laval Ab | Mixer for mixing of liquids or suspensions and method for mixing |
| US5728893A (en) * | 1995-12-06 | 1998-03-17 | Union Carbide Chemicals & Plastics Technology Corporation | Process using multistaged reactors |
| WO2000068496A1 (en) * | 1999-05-07 | 2000-11-16 | Kvaerner Pulping Ab | Feeding device and process and feeding system which utilise the feeding device |
| US20030194361A1 (en) * | 1999-05-07 | 2003-10-16 | Lennart Westerberg | Feeding device and process and feeding system which utilise the feeding device |
| US7179437B2 (en) * | 1999-05-07 | 2007-02-20 | Kvaerner Pulping Ab | Feeding device and process and feeding system which utilize the feeding device |
| US20080025143A1 (en) * | 2004-09-15 | 2008-01-31 | Hiroaki Ohashi | Apparatus and Method for Solid-Liquid Contact |
| US8596858B2 (en) * | 2004-09-15 | 2013-12-03 | Kureha Corporation | Apparatus for solid-liquid contact |
| US20160121276A1 (en) * | 2014-10-31 | 2016-05-05 | Quantum Technologies, Inc. | Dynamic mixing assembly with improved baffle design |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3194638A (en) | Combined slaker-causticizer apparatus | |
| US3222141A (en) | Digesting apparatus | |
| US2391738A (en) | Liquid treating apparatus | |
| US3307915A (en) | Apparatus for continuous calcination of gypsum | |
| US3017951A (en) | Transfer of gases into and from liquid media | |
| US3181931A (en) | Process for producing phosphoric acid | |
| US2425372A (en) | Apparatus and process for improving separation of clarified liquid from a slurry by maintaining a slurry circulation including a flow of slurry adjacent the separation interface | |
| US5145556A (en) | Single-stage slaking and causticizing method | |
| CN212092235U (en) | Phenyl silicone rubber production device for quickly separating hydrogen chloride gas | |
| US2404223A (en) | Method of and apparatus for treating sewage | |
| US2539732A (en) | Liquid and solids processing apparatus | |
| US2343185A (en) | Acetylene generation | |
| US3684651A (en) | Digestion of fibre pulp from vegetable raw material including pulp level controls | |
| US2245583A (en) | Liquid treating process and apparatus | |
| US3322505A (en) | Apparatus for treating substances in several stages | |
| CN109316837A (en) | A kind of lime kiln dust removal device and method | |
| US2907712A (en) | Apparatus for anaerobic digestion | |
| US3425899A (en) | Method and apparatus for breaking foam on foaming liquids and use thereof in oxidation system for regeneration of black liquor in sulfate pulp process | |
| US2276300A (en) | Liquid treating process and apparatus | |
| US2368354A (en) | Liquid treating apparatus and process | |
| CN217578657U (en) | Novel sludge dewatering equipment | |
| US2721173A (en) | Water treating apparatus | |
| US2738174A (en) | Reaction apparatus for continuous operation | |
| US2509695A (en) | Clarifying process and apparatus | |
| US2582317A (en) | Tank reactor |