SE202327C1

SE202327C1 -

Info

Publication number: SE202327C1
Application number: SE146564A
Authority: SE
Priority date: 1964-02-06
Filing date: 1964-02-06
Publication date: 1966-03-01

Description

Uppfinnare: W Holmberg och H Mueller Prioritet begard fretn den 19 f ebruari 1963 (Parbundsrepubliken Tyskland) Foreliggande uppfinning hanfor sig till en klor-alkalielektrolyscell och avser sarskilt ett vid anden av en sadan cell anordnat amalgamlas. Inventors: W Holmberg and H. Mueller Priority requested from 19 February 1963 (Federal Republic of Germany). The present invention relates to a chlor-alkali electrolysis cell and relates in particular to an amalgam glass arranged at the spirit of such a cell.

Kloralkalielektrolysceller enligt kvicksilverforfarandet besta vanligen av ett brett trag, vars botten är tackt med flytande kvicksilver. Kvicksilvret är under drift katodiskt polariserat och alkalimetall avskiljes elektrolytiskt darpa. Pa sin vag genom elektrolyscellen upptager kvicksilvret, beroende pa strombelastningen och kvicksilvercirkulationen, 0,1 till 0,8 viktprocent alkalimetall. Det bildade alkaliamalgamet lamnar elektrolyscellen, varvid det passerar ett amalgamlas, for att sedan omedelbart eller efter att ha flutit genom en sarskild tvattkammare komma fram till sonderdelaren. Dar sonderdelas amalgamet i narvaro av grafitkorn med vatten, varvid det bildas alkalihydroxidlosning, vale och nastan rent kvicksilver. Det senare pumpas anyo in I elektrolyscellen. Chloral alkali electrolysis cells according to the mercury process usually consist of a wide funnel, the bottom of which is filled with liquid mercury. During operation, the mercury is cathodically polarized and alkali metal is electrolytically separated by dolphin. On its way through the electrolytic cell, the mercury, depending on the current load and the mercury circulation, absorbs 0.1 to 0.8% by weight of alkali metal. The alkali amalgam formed leaves the electrolysis cell, passing an amalgam glass, and then immediately or after flowing through a special washing chamber to reach the probe divider. There, the amalgam is probed in the presence of graphite grains with water, forming alkali hydroxide solution, vale and almost pure mercury. The latter is pumped anyo into the electrolytic cell.

En inom tekniken ofta anvand utfOringsform av amalgamlaset aterges schematiskt i tvarsnitt i fig. 1. Det med 1 betecknade amalgarnet flyter frail elektrolysrummet 2 after att ha passerat fordjupningen 4 in i sanderdelningsrummet 3. Darvid är det for undvikande av bakflode i elektrolyscellen n8dvandigt, att det foreligger en nivaskillnad mellan amalgamytan i fordjupningen vid cellsidan och amalgamytan i sjalva cellen. Amalgamets skikttjocklek vid overgangen frail cellen till fOrdjupningen ar, sksom synes vid 5 i figuren, pa grund av den hogre stromningshastigheten minskad i forhallande till amalgamets skikt tjocklek i cellen. Amalgamets niva pa cellsi-- dan av fOrdjupningen bestammes den i cellen befintliga saltlosningen och klorgastrycket. Det maste emellertid i aila fall sakerstallas, att amalgamnivan pa eellsidan av fordjupningen. inte kan stiga hogre an cellbottnen 6. Skiljevaggen 7 skall doppa ned ungefar 20 till 30 mm i amalgamet. An embodiment of the amalgam glass often used in the art is shown schematically in cross section in Fig. 1. The amal yarn denoted by 1 flows from the electrolysis chamber 2 after passing the recess 4 into the sand division chamber 3. In order to avoid backflow in the electrolysis cell, it is necessary to there is a level difference between the amalgam surface in the depression at the cell side and the amalgam surface in the cell itself. The layer thickness of the amalgam at the transition from the cell to the depression is, as can be seen at 5 in the figure, due to the higher flow rate reduced in relation to the layer thickness of the amalgam in the cell. The level of the amalgam on the cell side of the depression is determined by the saline in the cell and the chlorine gas pressure. In all cases, however, it must be ensured that the amalgam level is on the other side of the depression. can not rise higher than the cell bottom 6. The separator cradle 7 should dip about 20 to 30 mm into the amalgam.

Ett las av detta slag dr behaftat med nackdelar. Det kan inte hindra, att det strommande amalgamet for med sig saltlosning frail elektrolyscellen till sonderdelaren, varvid huvudmangden av den medforda saltlosningen fore-. ligger i dispergerad form i amalgamet. For att rada hot pa denna olagenhet foredrager man att utforma fordjupningens utlopp 8 tamligen brett fOr att ge amalgamet i sjalva fordjupningen tillfalle att stromma lugnare och lata den inneslutna saltlosningen stiga upp i cellen. Trots denna atgard är avskiljningen av saltlosningen ofullstandig, sa att vid stora kvicksilverceller med en belastning av 50 till 200 kA den frail sonderdelaren kommande ungefdr 50-procentiga luten innehaller 50 till 150 mg/1 NaCI, aven om kloridfritt vatten anvandes for sonderdelningen. Bortforandet av saltlosning kan aven begransas genom att man mellan cellen och sonderdelaren insatter en sarskild avdelning, dar det genomstrommande amalgamet tvattas med vatten. A read of this kind has its drawbacks. It cannot prevent the flowing amalgam from carrying saline from the electrolytic cell to the probe divider, whereby the bulk of the entrained saline occurs. lies in dispersed form in the amalgam. In order to counteract this maladaptation, it is preferred to design the outlet 8 of the depression rather wide in order to allow the amalgam in the depression itself to flow more calmly and allow the entrained saline solution to rise into the cell. Despite this action, the separation of the saline solution is incomplete, so that in the case of large mercury cells with a load of 50 to 200 kA, the frail probe divider, approximately 50% liquor, contains 50 to 150 mg / l NaCl, although chloride-free water was used for the probe division. The removal of saline solution can also be limited by inserting a special compartment between the cell and the probe divider, where the flowing amalgam is washed with water.

Bada metoderna betyda dock en merkostnad vad betraffar kvicksilver. I tvattavdelningen bildas dessutom s. k. kvicksilversmor varigenom driften av elektrolyscellen och den vi-dare bearbetningen av amalgamet betydligt forsvaras. Denna »kvicksilversmon kallade Dupl. kl. 12 IL: 1 2 viskosa massa besthr i vanliga fall av amalgam och dari dispergerade vatskor och gaser, Man bar nu funnit, att medbringandet av saltlosningen fran elektrolyscellen med stromman.de kvicksilverkatoder till amalgamsonderdelaren kan nastan fullstandigt forhindras med ett la.s, som bestar av en med amalgam fylld fordjupning, van i en skiljevagg ovanifran delvis stracker sig ned, varvid hinder aro anOrdnade utmed amalgamets vag fean uttradeselektrolyscellen till fordjupningen, om hindren aro anordnade pa en yta, som är nedsankt i forhallande till elektrolysrummets hot-ten och ligger djupare och mynnar ut i fordjupningen och om hindren lOpa tvars mot stromningsriktningen for amalgamet Over ytans hela bredd. Both methods, however, mean an additional cost in terms of mercury. In the washing department, so-called mercury butter is also formed, whereby the operation of the electrolytic cell and the further processing of the amalgam is considerably defended. This "mercury monkey called Dupl. at 12 IL: 1 2 Viscous pulp usually consists of amalgam and dispersed liquids and gases. It has now been found that the entrainment of the salt solution from the electrolytic cell with the stromman.de mercury cathode to the amalgam subdivision can be almost completely prevented with a laser of a depression filled with amalgam, accustomed to a partition wall from above partially extending downwards, whereby obstacles are arranged along the wave of the amalgam exiting the electrolytic cell to the depression, if the obstacles are arranged on a surface which is submerged in relation to the heat of the electrolysis room and lies deep and opens into the depression and if the obstacles run across the direction of flow of the amalgam across the entire width of the surface.

En lilmplig utforingsform av laset enligt foreliggande uppfinning Merges schematiskt I fig. 2. Amalgamet 10 flyter frail cellrummet 11 efter att ha passerat fordjupningen 15 in i sonderdelarrummet 12. Innan amalgamet lo-per in i fordjupningen 15 flyter det fram Over den horisontella eller svagt lutande ytan 16, som är fOrsedd med tvars mot amalgamets stromningsriktning anordnade hinder 17 i form av ribbor. Ytan 16 Or anordnad nagot lagre an cellbottnen 14 och mynnar ut i fordjupningen. Amalgamnivan pa cellsidan av utloppsfordjupningen halles lampligen pa en sadan hojd, att hindren forbliva tackta med ungefar 5 mm amalgam. Detta kan latt ernas genom att nivan vid amalgamuttradet fran fordjupningen, motsvarande saval vatskepeLama vid cell- och sonderdelarsidan som gastrycken vid hada sidorna, halles mer eller mindre hog. Genom nivaskillnaden mellan amalgamytan vid fordjupningens cellsida och cellen kommer amalgamets skikttjocklek pa grund av den okade stromningshastigheten att minskas, sasom liar antytts med 13 i fig., och claimed fOrhindras bakflode i cellen. A suitable embodiment of the laser according to the present invention is schematically shown in Fig. 2. The amalgam 10 flows from the cell space 11 after passing the recess 15 into the probe divider space 12. Before the amalgam runs into the recess 15, it flows over the horizontal or slightly inclined the surface 16, which is provided with obstacles 17 in the form of ribs arranged transversely to the direction of flow of the amalgam. The surface 16 is arranged slightly lower than the cell bottom 14 and opens into the depression. The amalgam level on the cell side of the outlet depression is suitably kept at such a height that the obstacles remain filled with approximately 5 mm of amalgam. This can be facilitated by keeping the level at the amalgam line from the depression, corresponding to the water vessels at the cell and probe divider side, as well as the gas pressures at the hot sides, more or less high. Due to the level difference between the amalgam surface at the cell side of the depression and the cell, the layer thickness of the amalgam will be reduced due to the increased flow rate, as indicated by 13 in Fig., And claimed to prevent backflow in the cell.

En utloppsfordjupning for amalgam enligt foreliggande uppfinning ager en mycket verksam sparrverkan for medbringande saltlosping. Vid drift med stora kvicksilverceller med en belastning pa omkring 50 till 200 kA visar den i sonderdelaren bildade 50-procentiga luten en koksalthalt pa 3 till 12 mg/1, nar kloridfritt vatten anvandes for sonderdelningen. En ytterligare fordel med fordjupningen enligt foreliggande uppfinning bestar i att fOrdjupningens genomlopp 18 kan Wallas mycket trangt. I vanliga fall uppgar genomloppets bredd bara till omkring 10 till 20 mm mot 30 till 50 mm vid genomloppet 8 hos den i fig. 1 atergivna kanda anlaggningen, sa att ansenliga kvicksilvermangder kunna insparas vid cellfyllningen. An outlet recess for amalgam according to the present invention acts as a very effective ratchet effect for entraining salt flossing. When operating with large mercury cells with a load of about 50 to 200 kA, the 50% liquor formed in the probe divider shows a salinity of 3 to 12 mg / l, when chloride-free water is used for the probe division. A further advantage of the recess according to the present invention is that the passage 18 of the recess can be very narrow. In normal cases, the width of the passage only amounts to about 10 to 20 mm, compared with 30 to 50 mm at the passage 8 of the jug plant shown in Fig. 1, so that considerable amounts of mercury can be saved during the cell filling.

Claims

Patent claim: Read for electrolytic cells with flowing mercury, consisting of an amalgam-filled depression, in which a partition wall projects, obstacles being arranged on the amalgam web of the electrolytic cell outlet to the depression, characterized in that the obstacles are arranged on a surface which is arranged on a surface immersed in relation to the bottom of the electrolytic cell and opens into the depression and that the obstacles run across the direction of flow for the amal yarn over the entire width of the surface. Request publications: