Electrochemical cells comprising fluidized bed electrodes

Claim 2

An electrode arrangement for an electro-chemical cell comprising an electrode chamber of rectangular horizontal crosssection, a bed of electrically conducting or semi-conducting particles enclosed by said chamber, which chamber in use of the cell is adapted to permit liquid flow upwardly through the bed of particles substantially uniformly over horizontal cross-sections of the chamber, electrically conducting means establishing electrical connection with said particles, at least one side wall of said chamber comprising, at least in part, a permeable or semi-permeable diphragm, the chamber having a tapered bottom portion wherein horizontal cross-sections of the flow path for said liquid flowing through the chamber gradually increase to the full horizontal cross-sectional area of the chamber, the chamber being effectively closed at its lower end, and an inlet into the electrode chamber adjacent the base of said tapered bottom portion, said inlet comprising a slot substantially longer in its horizontal dimension than in its vertical dimension extending substantially across the full horizontal width of said tapered portion, said slot opening into said tapered bottom portion from the side thereof which is opposite the said wall comprising at least in part the permeable or semi-permeable diaphragm, said vertical dimension of the slot being small enough to prevent the majority of said particles contained within the chamber from passing out of the chamber through the slot when the upward flow of liquid ceases.

Claim 3

An electrode arrangement for an electro-chemical cell comprising an electrode chamber of rectangular horizontal cross-section, a bed of electrically conducting or semi-conducting particles enclosed by said chamber, which chamber in use of the cell is adapted to permit liquid flow upwardly through the bed of particles substantially uniformly over horizontal cross-sections of the chamber, electrically conducting means establishing electrical connection with said particles, at least one side wall of said chamber comprising, at least in part, a permeable or semi-permeable diphragm, the chamber having a tapered bottom portion wherein horizontal cross-sections of the flow path for said liquid flowing through the chamber gradually increase to the full horizontal cross-sectional area of the chamber, the chamber being effectively closed at its lower end, and an inlet into the electrode chamber adjacent the base of said tapered bottom portion, said inlet comprising a slot substantially longer in its horizontal dimension than in its vertical dimension extending substantially across the full horizontal width of said tapered portion, said slot opening into said tapered bottom portion from the side thereof which is opposite the said wall comprising at least in part the permeable or semi-permeable diaphragm, said vertical dimension of the slot being small enough to prevent the majority of said particles contained within the chamber from passing out of the chamber through the slot when the upward flow of liquid ceases.

Claim 4

An electrode arrangement for an electro-chemical cell comprising an electrode chamber of rectangular horizontal cross-section, a bed of electrically conducting or semi-conducting particles enclosed by said chamber, which chamber in use of the cell is adapted to permit liquid flow upwardly through the bed of particles substantially uniformly over horizontal cross-sections of the chamber, electrically conducting means establishing electrical connection with said particles, at least one side wall of said chamber comprising, at least in part, a permeable or semi-permeable diphragm, the chamber having a tapered bottom portion wherein horizontal cross-sections of the flow path for said liquid flowing through the chamber gradually increase to the full horizontal cross-sectional area of the chamber, the chamber being effectively closed at its lower end, and an inlet into the electrode chamber adjacent the base of said tapered bottom portion, said inlet comprising a slot substantially longer in its horizontal dimension than in its vertical dimension extending substantially across the full horizontal width of said tapered portion, said slot opening into said tapered bottom portion from the side thereof which is opposite the said wall comprising at least in part the permeable or semi-permeable diaphragm, said vertical dimension of the slot being small enough to prevent the majority of said particles contained within the chamber from passing out of the chamber through the slot when the upward flow of liquid ceases.

Claim 5

An electrode arrangement as claimed in claim 1, wherein said tapered bottom portion is wedge form.

Claim 6

An electro-chemical cell comprising at least one electrode arrangement as claimed in claim 1.

Claim 7

An electrode arrAngement for an electro-chemical cell comprising an electrode chamber of rectangular horizontal cross-section having therein a multitude of electrically conducting or semi-conducting particles and electrically conducting means establishing electrical connection with said particles, said particles being in the form of a fluidized bed by action of liquid flowing upwardly through said chamber substantially uniformly over horizontal cross-sections of the chamber, the improvement which comprises providing said chamber with a lower portion of wedge form that tapers downwardly from the full cross-sectional area of the electrode chamber to the bottom of the lower portion and an inlet slot adjacent said bottom which slot enters into said lower portion at the side, said slot extending substantially across the full horizontal width of said lower portion and having a vertical dimension so narrow that it prevents the majority of said particles contained within said chamber from passing out of said chamber when said upward flow of liquid ceases upon shut-down of the cell.

Claim 8

An electrode arrAngement for an electro-chemical cell comprising an electrode chamber of rectangular horizontal cross-section having therein a multitude of electrically conducting or semi-conducting particles and electrically conducting means establishing electrical connection with said particles, said particles being in the form of a fluidized bed by action of liquid flowing upwardly through said chamber substantially uniformly over horizontal cross-sections of the chamber, the improvement which comprises providing said chamber with a lower portion of wedge form that tapers downwardly from the full cross-sectional area of the electrode chamber to the bottom of the lower portion and an inlet slot adjacent said bottom which slot enters into said lower portion at the side, said slot extending substantially across the full horizontal width of said lower portion and having a vertical dimension so narrow that it prevents the majority of said particles contained within said chamber from passing out of said chamber when said upward flow of liquid ceases upon shut-down of the cell.

Claim 9

An electrode arrangement as claimed in claim 4, wherein said electrically conducting means comprises at least one electric current conducting member positioned within said chamber, part at least of said member being at a level above the upper extension of said chamber lower portion.

Claim 10

An electrode arrangement as claimed in claim 4, wherein said chamber lower portion extends to only a part of the effective height of the fluidized bed of particles.

Claim 11

An electrode arrangement as claimed in claim 4, wherein a tubular feed duct is provided to feed liquid to said slot and the junction between said duct and slot is shaped to provide a smooth transition from the duct to substantially the full width of said slot.