1. Field of the Invention
This invention relates to apparatus for the generation of hydrogen and oxygen by the electrolysis of water.
2. Summary of the Background Art
Conventional apparatus for generating hydrogen and oxygen by the electrolysis of water includes at least one anodic cell, and at least one cathodic cell, with the cells being filled with a common electrolyte, including water and a salt making the water electrically conductive. An electrical current is driven through the electrolyte between a positive electrode, or anode, within the anodic cell(s) and a negative electrode, or cathode, causing the water molecules to dissociate into positive hydrogen ions, which are driven to form hydrogen bubbles at the cathode(s), and into negative oxygen ions, which are driven to form oxygen bubbles at the anode(s).
One problem associated with the operation of such apparatus arises from a tendency of metals used to form the anode(s) to form ions that are electrodeposited on the cathode(s), depleting material from the anode(s) and causing a possibly uneven and undesirable growth of material on the cathode(s). What is needed is a way to minimize this effect.
U.S. Pat. Nos. 5,846,390 and 6,846,394 each describe apparatus for generating alkaline and acidic water by means of electrolysis, with the electrode polarity being switched to clean an accumulation of a scale composed of materials such as calcium carbonate, calcium hydroxide, and magnesium hydroxide, which forms on the electrode at which alkaline water is accumulated. In the device of U.S. Pat. No. 5,846,390, a cleaning cycle occurs at a time when the water is not being used, with water generated during the cleaning process being drained away. In the device of U.S. Pat. No. 6,846,394, the outputs of the electrolytic cells are switched when the polarities of the electrodes are switched to prevent the formation of scale at the electrode.
U.S. Pat. No. 3,755,113 describes an apparatus for electrorefining nickel, in which a thick coating of nickel is electrodeposited on the cathode, with the process including switching the polarity of the cathode for 3.0 to 8.0 percent of the time, with the process resulting in a more even deposition of the nickel, apparently by reducing variations in the concentration of nickel salts in the solution adjacent the cathode.
While such apparatus uses polarity switching to avoid particular problems occurring at the electrodes during continued operation at a single polarity, what is needed is such an electrolytic apparatus producing hydrogen and oxygen with polarity switching, with the mixing of hydrogen and oxygen bubbles within the anodic and cathodic cells being prevented so that an explosive gas mixture is not produced.
Other references from the patent literature describe configurations for effective electrodes for use in the electrolytic production of hydrogen and oxygen. In general, such methods provide a substantial surface area in which contact occurs between the electrode and the electrolyte. For example, U.S. Pat. App. Pub. No. 2005/011765 A1 describes such electrodes as being formed from a number of spaced-apart disks that are vibrated to facilitate the movement of gas bubbles away from the disks, while U.S. Pat. No. 5,879,522 describes the use of an anode and cathode each including an electrically conductive sheet and adjacent discrete conductive ultramicroelectrode particles.
It is a first objective of the invention to provide an apparatus for generating hydrogen and oxygen in which the polarities of the electrodes within electrolytic cells are intermittently switched to reduce the accumulated effect of plating the electrode material from one electrode to another.
It is another objective of the invention to provide a means providing relative movement between the conduits receiving hydrogen and oxygen and electrolytic cells when the polarities of electrodes within the electrolytic cells are switched, so that one such conduit always receives hydrogen while the other conduit always receives oxygen.
In accordance with a first aspect of the invention, apparatus is provided for generating hydrogen and oxygen by electrolysis of water. The apparatus includes a plurality of electrolytic cells, an electrolyte conduit, a circuit, switching means, an oxygen receiving conduit, and a hydrogen receiving conduits. Each of the electrolytic cells includes an electrode and a container holding a portion of an electrolytic fluid including water in contact with the electrode. The electrolyte conduit extends among the electrolytic cells, holding a portion of the electrolytic fluid in communication with the electrolytic fluid within each of the electrolytic cells. The circuit causes electrical current to flow through positive and negative terminals connected to the electrodes and through the electrolytic fluid within the electrolytic cells and within the conduit during production cycles. The switching means operates during switching cycles occurring between production cycles, in which hydrogen and oxygen is produced, to cause each electrode within the plurality of electrolytic cells to be electrically connected alternately to the positive and negative terminals of the circuit during production cycles. The hydrogen receiving conduit is connected to each electrolytic cell having an electrode electrically connected to the negative terminal of the circuit; while the oxygen receiving conduit is connected to each electrolytic cell having an electrode electrically connected to the positive terminal of the circuit.
Preferably, the apparatus additionally includes an interface plate extending between adjacent electrolytic cells, each of which includes a cell opening extending through the interface plate, with the hydrogen receiving conduit and the oxygen receiving conduit each including conduit opening tubes extending away from the interface plate and moving along the interface plate between adjacent cell openings during switching cycles. Preferably, each of the electrolytic cells extends downward from one of the cell openings, with the conduit opening tubes extending upward from the interface plate, and with a level of the electrolytic fluid being held within the conduit opening tubes above each of the cell openings. The cell openings are preferably spaced apart in a circular pattern within the interface plate, with the switching cycle including relative rotation between the interface plate and the conduit opening tubes about a center of the circular pattern.
In a first version of the invention, the electrolytic cells remain stationary, while the hydrogen receiving conduit and the oxygen receiving conduit, each of which include a flexible portion, move between the cells. Preferably, the cell openings are equally spaced in the circular pattern in the interface plate, with the conduit opening tubes of the hydrogen receiving conduit being disposed in a circular pattern alternating with the conduit openings of the oxygen receiving conduit, and with the conduit openings being moved between adjacent cell openings in alternate directions during alternate switching cycles.
In a second version of the invention, the oxygen receiving conduit and the hydrogen receiving conduit remain stationary, with the electrolytic cells being moved between the hydrogen receiving conduit and the oxygen receiving conduit.
The apparatus may additionally include an overflow tube, connected to the electrolyte conduit, extending upward to an overflow edge from which the electrolytic fluid overflows to maintain a prescribed level within each of the conduit opening tubes. A fluid level switch, operating when the electrolytic fluid within the overflow tube falls below a predetermined level, causes a valve to opening, so that additional electrolytic fluid to enter the electrolytic cells.
The invention will first be described with reference being made to
With the flow of current through the electrolytic fluid 26, oxygen is formed at the electrodes 22 that are electrically connected as anodes, with oxygen bubbles moving upward from the surfaces of such electrodes 22 to release a gas collected by the oxygen receiving conduit 20. Similarly, hydrogen is formed at the electrodes 22 that are electrically connected as cathodes, with hydrogen bubbles moving upward from the surfaces of such electrodes 22 to release a gas connected by the hydrogen receiving conduit 18.
The apparatus 10 is additionally provided with means for establishing a flow of the electrolyte 26 within the apparatus 10 and for replenishing the electrolyte 26 as the water it contains is converted into hydrogen and oxygen. The electrolyte 26 is added through an electrolyte supply tube 46, which empties the electrolyte into a central reservoir tube 48, extending upward with a central housing column 50 from an reservoir channel 52 within the housing base 27 of the generator housing 14. The reservoir channel 52 is in tern connected by a number of holes 54 within the housing base 27 to an inner annular space 56 extending between the container 24 of each of the electrolytic cells 22 and an intermediate cylinder 58 extending around the container 24. The container 24 includes a number of holes 50. permitting a flow of the electrolytic fluid 26 between the inner annular space 56 and the space 62 within the container 24.
A float 84 slidably mounted within the level control tube 78 actuates the float-operated switch 72 when the level of the electrolytic fluid 26 falls to an offset distance below the overflow edge 74. Referring again to
In accordance with the invention, the conduit housing 16 and the generator housing 14 are movable relative to one another, with movement between these housings 14, 16 being used along with switching the electrical polarities of the electrodes 22 to maintain alignment between the conduit opening tubes 36 of the hydrogen receiving conduit 18 with the cell openings 34 of electrolytic cells 12 having electrodes 22 functioning as cathodes, and to maintain alignment between the conduit opening tubes 36 of the oxygen receiving conduit 20 with the cell openings 34 of the electrolytic cells 12 having electrodes 22 functioning as anodes.
In the example of
Preferably, the cell openings 34 are equally spaced in a circular pattern in the interface plate 32, with the conduit opening tubes 36 of the hydrogen receiving conduit 18 being disposed in a circular pattern alternating with the conduit opening tubes 36 of the oxygen receiving conduit 20, and with the conduit openings 18 being moved between adjacent cell openings in alternate directions during alternate switching cycles. Such switching cycles occur between production cycles, in which hydrogen and oxygen is produced within the apparatus 10.
The hydrogen receiving conduit 18 and the oxygen receiving conduit 20 each include a pair of conduit receptacles 102 extending upward from the conduit opening tubes 36, which extend between the interface plate 94 and the top plate 96 for attachment to a flexible conduit portion 104 that deflects with rotation of the conduit housing 16. As shown in
While only part of the hydrogen receiving conduit 18 is shown in the drawings, the flexible conduit portions 104 of this conduit 18 are understood to be joined in a single hydrogen receiving structure to form the hydrogen receiving conduit 18. Similarly, while only part of the oxygen receiving conduit 20 is shown, the flexible conduit portions 104 of this conduit 20 are understood to be joined in a single oxygen receiving structure to form the oxygen receiving conduit 20.
Preferably, such rotational movement occurs in alternating directions, with the conduit housing 16 being rotated through a 90-degree angle in a first direction, with the apparatus 10 then being used to produce hydrogen and oxygen for a time, and with the conduit housing then being rotated through a 90-degree angle in a direction opposite the first direction. In this way, the flexible conduit portions 104 are required to undergo only the deflections associated with 90 degrees of rotation of the conduit housing 16.
Referring to
As shown in
The alternative apparatus 130 rests upon a base 142, which provides an upward-extending central column 144 to which a top plate 146 of the receptacle housing 132 is rigidly attached. The central column 144 additionally includes bearing surfaces 148 upon which an interface plate 150 and a lower structure 152 of the generator housing 134 are rotatably of mounted. The interface plate 150 includes a groove 154 for providing rotational movement to the generator housing 134 through a drive belt 156. In turn, the drive belt 156 is driven by a motor attached, as described above in reference to
Each of the electrodes 135 is attached to a contact spring 158, providing electrical contact with a contact plate 160 attached to the base 142. Since both the receptacle housing 132 and the base 142 remain stationary, a positive voltage is applied to the contact plates 160 directly beneath the conduit receptacles 162 receiving oxygen within the receptacle housing 132, while a negative voltage, relative to the positive voltage, is applied to the contact plate 160 directly below the conduit receptacles 162 receiving hydrogen within the receptacle housing 132. While the polarity of an individual electrodes 135 is switched by its movement between adjacent contact plates 160 having different polarities, the flow of current through all of the electrodes 135 may be interrupted before the rotational movement of the generator housing 132 and resumed after the completion of this rotational movement, with time being provided for bubbles of hydrogen and oxygen to leave the electrolytic fluid 140 within the electrolytic cells 138 before the rotational movement. An upward force, acting upon the generator housing 132 due to the deflection of the contact springs 158, holds sealing elements 160 within the interface plate 150 of the generator housing 134 in contact with an interface plate 164 of the receptacle housing 132, while sealing elements 165 of the interface plate 164 are held against the interface plate 150, preventing leakage of the electrolytic fluid 140 between the interface plates 150, 164. Additional structural elements of the generator housing 134 include, for example, a cylinder 166 extending between the lower structure 152 and the interface plate 150 and a number of tensioning rods 167.
Within the alternative apparatus 130, electrolytic fluid 140 is provided through a central supply hose 168 to central supply tube 170 within the central column 144, which additionally includes a number of holes 172 extending radially to connect the central supply tube 170 with an annular supply reservoir 174 within the lower structure 152 of the generator housing 134. This annular supply reservoir 172 is in turn connected to the space 176 within each of the electrolytic cells 138 through a hole 178 at the bottom of the cell 138. A number of slots 180 and holes 182 disposed within the interface plate 150 in the manner described above in reference to
While the invention has been described in its preferred forms or embodiments with some degree of particularity, it is understood that this description has been given only by way of example, and that many variations can be made without departing from the spirit and scope of the invention, as defined in the appended claims.