US3549511A - Apparatus for the decomposition of an alkali metal mercury amalgam - Google Patents

Apparatus for the decomposition of an alkali metal mercury amalgam Download PDF

Info

Publication number
US3549511A
US3549511A US747304A US3549511DA US3549511A US 3549511 A US3549511 A US 3549511A US 747304 A US747304 A US 747304A US 3549511D A US3549511D A US 3549511DA US 3549511 A US3549511 A US 3549511A
Authority
US
United States
Prior art keywords
decomposition
mercury
pump
chamber
amalgam
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
Application number
US747304A
Other languages
English (en)
Inventor
Robert Schoberle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Solvay SA
Original Assignee
Solvay SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Solvay SA filed Critical Solvay SA
Application granted granted Critical
Publication of US3549511A publication Critical patent/US3549511A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/005—Amalgam decomposition cells
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
    • C25B1/36—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in mercury cathode cells
    • C25B1/42—Decomposition of amalgams

Definitions

  • the apparatus comprises a common chamber which contains the piling used as a catalyst for the decomposition of the amalgam formed in a mobile mercury electrolytic cell and the pump which drives the recovered mercury back toward the cell for reuse.
  • a single tank also contained in the chamber provides for the storage of mercury collected during the decomposition which may be used as a drawing reserve for the centrifugal pump as as well as storage in the event the cell is stopped.
  • the present invention relates to vertical piles used for the decomposition of the amalgam of alkali metal formed in a mobile mercury cathode electrolytic cell. It concerns, more particularly, an apparatus and system for the decomposition of the amalgam which fiows or drips across a fixed bed of catalyst particles in contact with a decomposition liquid which is circulating countercurrent to the amalgam and for recycling the mercury thus obtained toward the mercury cell.
  • the deliver or driving device of the mercury must be capable of guaranteeing a flow on the order of 120 liters per minute at a manometric height often in excess of 3 meters, corresponding to the geometric height of the pile and to the loss of pressure in the delivery pipe, the length of which is substantially that of the cell, namely about 12 to 15 meters, and the section or profile of which is reduced as much as possible so as to limit the amount of mercury immobilized.
  • centrifugal pumps have been mounted outside the pile, in a large tank set up at the level of the base of the pile, in order to collect the mercury of the cell in the event of a stoppage of the installation.
  • the piling which catalyzes the decomposition of the finely divided amalgam and the centrifugal pump which drives the mercury resulting from this decomposition towards the electrolytic cell are arranged in a common chamber.
  • This common chamber simultaneously acts as the decomposition pile, the pump tank and the tank for the storage of mercury required in the event of a stoppage of the electrolytic cell.
  • the installation of the present invention for the decomposition of the amalgam of alkali metal formed in a mobile mercury cathode electrolytic cell and for the delivery of the mercury resulting from this composition toward the electrolytic cell comprises a chamber enclosing a fixed bed of catalyst on which the finely divided amalgam streams or drips in contact with decomposition liquid in countercurrent circulation and also encloses a mercury centrifugal pump.
  • a bafile is mounted in the chamber between the pump and the fixed bed of catalyst to prevent contact between the catalyst and at least the mobile components of the pump.
  • the common chamber which encloses the catalyst bed and the pump is sealed by means of a cover and is provided with means for storing the mercury which results from the decomposition reaction.
  • the common chamber acts as a decomposition pile, a storage tank for the mercury resulting from the decomposition, a mercury drawing reserve for the centrifugal pump and a means for storage of mercury in the event of a stoppage of the electrolytic cell.
  • the present installation is also provided with means for introducing the amalgam into the chamber and onto the fixed bed of catalyst in finely divided form and means for introducing the decomposition liquid into the chamber and into countercurrent contact with the amalgam.
  • FIG. 1 shows a device of the present invention in axial section and FIG. 2 represents the same device in horizontal section following lines A-A of FIG. 1.
  • FIGS. 3, 5, and 7 also show in axial section different embodiments of the devices of the present invention, and FIGS.
  • the electrolytic cell 1 is in communication by means of a conduit or pipe 2 with a cylindrical chamber 3 which is accessible from the floor 4 of the electrolysis room.
  • the chamber 3 houses a fixed bed of catalyst 5, generally a piling of graphite particles.
  • Two perforated discs 6 and 7 are held between the lateral wall of chamber 3 and a perforated cylinder or baflle 8 which connects the two discs 6 and 7 and extends toward the top to a cover 9.
  • a conduit or pipe 10 is provided at the base of chamber 3 for the introduction of the decomposition liquid or solution, and an exit tube 11 for the decomposition solution is provided above the catalyst bed.
  • a pipe 12 is also provided above the bed of catalyst particles for the escape of gases, especially hydrogen formed during the course of the decomposition.
  • At the bottom of the chamber 3 inclined walls lead toward a collector 14 which is situated approximately coaxial with the axis of the cylinder 8.
  • a centrifugal pump 15 is situated in the cylinder 8 which is free from piling. The centrifugal pump 15 is introduced through the top of the chamber 3 with its casing 16 and its discharge pipe 17.
  • the casing 16 is provided with openings 18 for the circulation of the decomposition liquid or solution.
  • the pump 15 is moved or driven by the motor 19 by means of a long shaft 20 which rotates in the decomposition liquid or solution.
  • the motor assembly, shaft, pump, casing, and delivery pipe is supported by a plate 21 which seals the opening provided in the cover 9 for the passage of the pump 15.
  • a packing 22 assures the tightness of the shaft to the plates.
  • a plunger or tube 23 which forms a part of the plate 21 surrounds an upper part of the shaft 20 in order to prevent a massive loss of gas in the event of leakage at the packing 22.
  • the operation of the apparatus is carried out in the following manner.
  • the amalgam coming out of the electrolytic cell 1 flows through the conduit or pipe 2 into the chamber 3 where the amalgam is distributed in a finely divided state as it passes through the perforated discs 6 and 7 onto the piling of catalyst particles 5 which aids its decomposition.
  • the decomposition liquid which is usually water or dilute caustic alkali solution, although other suitable solutions such as polysulfides may be used, is introduced into the base of chamber 3 through conduit 10 and flows through the piling so as to contact the amalgam in a countercurrent stream, and the decomposition solution leaves the chamber through the pipe 11.
  • the perforated cylinder 8 and the openings 18 in the casing 16 permit the circulation of the decomposition liquid in the casing 16 so that the shaft 20 rotates in the decomposition liquid. Hydrogen formed during the course of the decomposition escapes through the pipe 12.
  • the mercury substantially free of alkali metal after it has flowed or dripped through the piling 5 in contact with the decomposition liquid, flows on the inclined bottom of the chamber 3 to the collector 14 which is situated approximately in the axis of the cylinder 8.
  • the mercury collector 14 provides a drawing reserve for the centrifugal pump 15.
  • the mercury gathered in the collector 14 has a double function: on the one hand, it assures the correct operation of the centrifugal pump by playing the role of a plug or stopper, absorbing the inevitable fluctuations in the flow of the mercury and maintaining the minimum level required by the pump, and on the other hand, it serves as a guard or barrier against the pumping of caustic alkali solution.
  • a widely proportioned conduit or pipe is required to prevent pumping of caustic alkali solution which immobilizes a considerable quantity of mercury.
  • the device of the present invention therefore, achieves a considerable economy in the amount of mercury immobilized compared to installations in current use. Moreover, the present invention eliminates the need for a large mercury storage tank with the concomitant requirement of means for rapid water circulation, recycling and refrigeration systems all required in conventional type installations wherein the centrifugal pump is mounted outside of the vertical decomposition pile. Whenever a stoppage of the cell is required or happens by accident, the mercury contained therein can be completely stored in chamber 3 without difficulty or inconvenience.
  • the pump assembly of the present device may be dismantled very rapidly in order to make a replacement or repairs and for general maintenance purposes. In effect, it is sufficient to unbolt plate 21 supporting the assembly. This operation does not require the removal of cover 9 and can be carried out in full safety at the same level of the floor 4 of the electrolysis room.
  • the installation or device of the present invention may be varied in several ways.
  • the cylindrical screen or baffie plate 8 which prevents contact between the shaft of the pump and the catalyst particles may be constituted by the casing of the pump itself.
  • FIGS. 3, 4, 5 and 6 This aspect of the invention is illustrated in FIGS. 3, 4, 5 and 6 wherein the piling particles 5 are prevented from contacting the shaft 20 by the pump housing or casing 16.
  • apertures 18 are provided, which have screens thereon, as shown in the drawing.
  • the pump casing assembly must be put in place before introduction of the piling; the latter is then emptied or removed by suction for example for the dismantling of the pump.
  • the delivery pipe 17 which recycles the mercury back to the electrolytic cell It is not essential for the delivery pipe 17 which recycles the mercury back to the electrolytic cell to be an integral part of the assembly of the centrifugal pump.
  • the delivery pump 17 protrudes directly from the mercury collector 14 and is therefore outside the chamber 3 of which it is an integral part.
  • This variant also makes it possible to increase the quantity of catalyst in the chamber 3, and accordingly, the capacity of the decomposition pile, without changing the dimensions of chamber 3, by the reduction in the section or profile of the perforated cylinder 8 due to the omission of the delivery pipe 17 therefrom.
  • FIGS. 5 and 6 Another variant of the present invention is illustrated in FIGS. 5 and 6, wherein the decomposition liquid or solution is not introduced at the base of the device through the conduit or pipe -10, but rather from the top through the pipe 24 which communicates with the top of the pump housing 16.
  • the casing 16 only communicates through its base, by means of one aperture 18 provided therein with the chamber 3.
  • the decomposition liquid introduced through the conduit 24 flows between the shaft 20 and the casing 16 and enters the decomposition vessel 3 through the screened aperture 18, so that the shaft 20 of the centrifugal pump constantly rotates in the entering decomposition liquid.
  • the shaft 20 of the pump rotates in water, whereas in the installations illustrated in the other figures, it runs in dilute caustic alkali solution.
  • the pipe 10 of FIG. 5 is used only to drain the vessel.
  • the shaft 20 is supported only by a bearing at its upper part; the shaft 20 is thus back balanced and submitted to bending stress. Accordingly, if it is running in caustic solution, caustic embrittlement may cause it to break. Therefore in this preferred embodiment, it is particularly desirable to have the shaft running in water as is possible with the installation illustrated in FIGS. and 6.
  • a further advantage in having the shaft rotate in water instead of caustic alkali solution, as is possible when the decomposition liquid is introduced at the top of the apparatus, is to prevent any of the caustic solution which results from the decomposition reaction from being lead away with the mercury into the electrolytic cell by the pump 15 through the mercury lift pipe 17.
  • the assembly of the centrifugal pump including the pump housing 16, and when present the cylindrical screen or baffie plate 8 and the mercury collector 14 do not have to occupy an appreciably axial position in the chamber 3; they may occupy any other position compatible with the desirable operation of the installation.
  • the pump for example, can be set up against the lateral wall of the chamber 3; the latter may also carry on its lateral wall a vertical by extending lateral protrusion to be used for housing the pump.
  • FIGS. 7 and 8 illustrate an embodiment of the present invention wherein the vessel 3 is provided with a vertically extending lateral protrusion which is substantially as high as the vessel to house the pump 15 and its housing 16.
  • the mercury delivery tube -17 is also located in the projection 25, however as previously indicated, this location is purely optional.
  • the protrusion 25 communicates with the rest of the vessel 3 through two apertures; an aperture 26 for gas at the top and an aperture 27 for mercury at the bottom.
  • Decomposition liquid which enters .the protrusion 25 through the top aperture 26 flows back to the vessel 3 through the bottom aperture 27 thus flowing downwardly in the protrusion 25 where the pump shaft 20 is rotating in the decomposition liquid.
  • Apparatus for the decomposition of an amalgam of alkali metal formed in a mobile mercury cathode electrolysis cell and for the delivery of the mercury resulting from the decomposition to said cell, wherein the decomposition takes place by contacting said amalgam with a decomposition liquid said apparatus comprising means defining a chamber, enclosed in said chamber a fixed bed of catalyst on which finely divided amalgam drips in contact with said decomposition liquid circulating counter-current to said amalgam, a centrifugal pump enclosed in said chamber for discharging mercury from said chamber, means connected to said pump for discharging mercury out of said chamber for delivery to said cell, a means for introducing said amalgam into said chamber and onto said fixed bed of catalyst, means for introducing said decomposition liquid into said chamber and into countercurrent contact with said amalgam, storage means for mercury resulting from said decomposition, said storage means also providing a drawing reserve for said centrifugal pump and being in communication with said bed of catalyst and said pump, means to remove gases from said chamber, and a baffie mounted in said chamber
  • a cover covers said chamber and is provided with an opening for the passage of said centrifugal pump and further comprising a motor mounted above said chamber for driving said pump, a support supporting said motor which seals the opening in said cover, a shaft extending from said motor through the entire height of said fixed bed of catalyst for driving said pump, and a casing surrounding said shaft suspending said pump from said support.
  • Apparatus according to claim 2 which further comprises a pipe in communication with said pump positioned substantially parallel to said shaft along said casing and passing through said support to discharge mercury resulting from said decomposition.
  • said means for introducing said decomposition liquid comprises means to introduce said decomposition liquid at the base of said chamber and in which said casing is provided with openings along its entire height for the passage of gases which form during the decomposition reaction and for passage of the decomposition liquid introduced at the base of the chamber.
  • Apparatus according to claim 1 including means to continuously remove during operation reacted decomposition liquid from said chamber.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Fire-Extinguishing Compositions (AREA)
US747304A 1967-07-26 1968-07-24 Apparatus for the decomposition of an alkali metal mercury amalgam Expired - Lifetime US3549511A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE701848 1967-07-26

Publications (1)

Publication Number Publication Date
US3549511A true US3549511A (en) 1970-12-22

Family

ID=3851228

Family Applications (1)

Application Number Title Priority Date Filing Date
US747304A Expired - Lifetime US3549511A (en) 1967-07-26 1968-07-24 Apparatus for the decomposition of an alkali metal mercury amalgam

Country Status (4)

Country Link
US (1) US3549511A (en, 2012)
BE (1) BE701848A (en, 2012)
GB (1) GB1215220A (en, 2012)
NL (1) NL6809743A (en, 2012)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4204937A (en) * 1978-01-24 1980-05-27 Oronzio Denora Impianti Elettrochimici S.P.A. Novel electrolytic amalgam denuder apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE14491C (de) * J. PlCHONNAT inMehun s. Yevre (Frankreich) Neuerung an Saughebern
GB846603A (en) * 1958-01-15 1960-08-31 Ici Ltd Improvements in or relating to a process for the production of caustic alkali solutions from alkali metal amalgams and to apparatus therefor
US3464910A (en) * 1964-06-15 1969-09-02 Edouard Charles Krebs Aqueous electrolysis cell for saline solutions,especially of alkali chlorides

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE14491C (de) * J. PlCHONNAT inMehun s. Yevre (Frankreich) Neuerung an Saughebern
GB846603A (en) * 1958-01-15 1960-08-31 Ici Ltd Improvements in or relating to a process for the production of caustic alkali solutions from alkali metal amalgams and to apparatus therefor
US3464910A (en) * 1964-06-15 1969-09-02 Edouard Charles Krebs Aqueous electrolysis cell for saline solutions,especially of alkali chlorides

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4204937A (en) * 1978-01-24 1980-05-27 Oronzio Denora Impianti Elettrochimici S.P.A. Novel electrolytic amalgam denuder apparatus

Also Published As

Publication number Publication date
NL6809743A (en, 2012) 1969-01-28
BE701848A (en, 2012) 1968-01-26
GB1215220A (en) 1970-12-09

Similar Documents

Publication Publication Date Title
US3291889A (en) Dielectric interrupter
US3549511A (en) Apparatus for the decomposition of an alkali metal mercury amalgam
CN113652700A (zh) 一种电解水制氢洗涤分离装置
US2336045A (en) Amalgam decomposition
CN214486234U (zh) 一种压力容器气液分离装置
GB516775A (en) Improvements in or relating to fused salt electrolysis cells
DK152858B (da) Vaeskeringskompressoraggregat
GB1137070A (en) Improvements in or relating to electrolysis cells
US2268454A (en) Washing machine
US3215504A (en) Plate tower
US3900010A (en) Method and apparatus for reverse circulating nuclear steam generator secondary fluid
US2307835A (en) Mercury cell
US2141047A (en) Gas and liquor treatment apparatus
US2916425A (en) Apparatus for the electrolysis of alkali metal salts and process therefor
SU505333A3 (ru) Парожидкостной сепаратор
US3118827A (en) Fused salt electrolysis cell
US3607705A (en) Pumping system
US3215614A (en) Amalgam decomposer
CN213761421U (zh) 一种电解阳极板脱模剂混合液的自动制作装置
RU2397141C2 (ru) Способ получения водорода и химический реактор для его осуществления
US3068165A (en) Mercury cathode electrolytic cell
KR20210009220A (ko) 전해조용 기액분리실
CN223089642U (zh) 一种乙炔发生器循环水泵用自引罐及泵送系统
CN104671305A (zh) 一种剩余氨水处理装置和工艺
CN215084998U (zh) 一种用于双氧水生产的氧化残液回收装置