Electrolytic water softener

Abstract

An electrolytic water softener which comprises a container, at least one cathode and at least one anode extending into the container, a power supply operatively connected to the cathode and anode, a vibrating device to vibrate the cathode, and a system for collecting material released from the cathode after operation of the vibration device.

Claims

1. An electrolytic water softener comprising: a container; at least one cathode extending into said container; at least one anode extending into said container; a power supply operatively connected to said at least one cathode and said at least one anode; means to vibrate said cathode; and a system for collecting material released from said cathode after operation of said means to vibrate said cathode.

2. The electrolytic water softener of claim 1 including a plurality of cathodes extending into said container.

3. The electrolytic water softener of claim 2 including a plurality of anodes extending into said container, said plurality of cathodes and said plurality of anodes being arranged sequentially.

4. The electrolytic water softener of claim 1 wherein said means to vibrate said cathode comprise mechanical means.

5. The electrolytic water softener of claim 1 wherein said means to vibrate said cathode comprise pneumatic means.

6. The electrolytic water softener of claim 1 wherein said cathodes are formed of a piezoelectric material.

7. The electrolytic water softener of claim 1 wherein said means to vibrate said cathode comprise an ultrasonic transducer.

8. The electrolytic water softener of claim 1 wherein said cathode is formed of a plastic material having a metallic exterior.

9. The electrolytic water softener of claim 1 wherein said anode is formed of a material selected from the group consisting of platinum mesh, lead oxides, mixed metal oxides, platinum materials, boron doped diamond.

10. The electrolytic water softener of claim 1 wherein said cathode is formed of a metal memory material.

11. The electrolytic water softener of claim 10 wherein said metal memory material is Nitinol or an alloy thereof.

12. The electrolytic water softener of claim 1 wherein said cathode is formed of an electrically conductive polymer in the shape of an angular pouch.

13. A method for softening water comprising the steps of: passing water through a container, the container having at least one cathode and at least one anode extending into said container; supplying power to said at least one cathode and said at least one anode, periodically vibrating said cathode; and collecting material released from said cathode.

14. The method of claim 13 wherein said step of vibrating said cathode comprises mechanically vibrating said cathode.

15. The method of claim 13 wherein said step of vibrating said cathode comprises the step of operating a transducer proximate said cathode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which:

[0037] FIG. 1 is a schematic view illustrating the arrangement of cathodes and anodes which may be utilized with a container to treat water; and

[0038] FIG. 2 is a schematic view illustrating an arrangement wherein precipitates are collected at the bottom of a container.

DETAILED DESCRIPTION OF THE INVENTION

[0039] As shown in FIG. 2, there is provided an electrolytic water softener which is generally designated by reference numeral 10.

[0040] Electrolytic water softener 10 includes a container 12 into which there are inserted a plurality of anodes 14 and a plurality of cathodes 16. An electrode holder or frame member 18 is secured to cathodes 16. A vibrator 20 is connected to one end of electrode holder 18 to impart vibrations thereto.

[0041] Electrolytic water softener 10 includes an inlet conduit 22 to container 12 and an outlet conduit 24. At the bottom of container 12, there is provided a precipitate discharge drain 26. A pump 28 is designed to pump fluid (including the precipitate) through a filter 30 with the filtered liquid re-entering container 12 by means of a return line 32.

[0042] As shown in FIG. 1, vibrator 20 is connected to each cathode 16 and in the illustrated embodiment, comprises a mechanical vibrator designed to impart pulses to electrode holder 18 and thus to cathodes 16. A base plate 34 is provided and springs 36 are mounted between base plate 34 and electrode holder 18.

EXAMPLE 1

[0043] The device of this invention used in this example for the removal of hardness from well water was a prototype consisting of a conical cylinder type reactor as shown in FIG. 2. The removal of hardness from the water was performed by an electrochemical cell that caused the hardness to deposit on its cathode. This hardness layer was then released from the cathode through the use of a mechanical vibrator which actuated every 30 minutes for a period of five seconds. The shaking of the cathode by the mechanical vibrator caused the hardness deposits to fall from the cathode and accumulate in the conical portion of the reactor. Water from this section of the reactor was periodically pumped through a two step filtration process consisting of two cartridge-type sediment filters. The first filtration stage was performed at a porosity of five microns and was followed by a second filtration stage of one micron porosity. The filtered water was then recycled back to the reactor. The vessel of the reactor had diameter of twenty inches, an overall height of thirty inches and a capacity of thirty US gallons.

[0044] The electrochemical cell consisted of fourteen metallic electrodes. Seven electrodes were comprised of a flat platinum plated niobium mesh measuring about six inches by about six inches each. The other seven electrodes were aluminum plates measuring about ten inches wide by about twenty inches long each. The seven platinum electrodes were connected together to define the anode and, similarly, the seven aluminum plates were connected together to define the cathode. These flat electrodes were alternatively positioned so as to face each other and connected to an opposite pole of the power supply such as to define seven consecutive electrolytic cells.

[0045] The direct current power supply was delivering a current of 19.5 amps and 19.5 volts. The water to be treated had an initial Total Hardness Concentration of 414 ppm which, according to Guidelines for Canadian Drinking Water Quality, is considered to be very hard water. This test water originated from a residential artesian well and was used “as is”, that is without the addition of any other chemicals. The Total Dissolved Solids (TDS) concentration of the test water was 410 ppm, which is equivalent to a conductivity of 820 uSiemens/cm.

[0046] About 30 gallons of this well water was placed in the reactor and treated for 150 minutes under the conditions described above. The treated water had a Total Hardness Concentration of 174 ppm, representing a reduction of 58%. After 500 minutes of treatment a reduction of 75% in Total Hardness was achieved yielding a final concentration of 84 ppm.

[0047] The experiment was repeated using 40 amps and a voltage of 40 volts, that is, double the values used in the initial experiment. The volume of water treated in the reactor was the same, namely, 30 US gallons. The doubling of the current density allowed the Total Hardness to be reduced 75% in a treatment time of 120 minutes, dropping from an initial concentration of 420 ppm to a final concentration of 108 ppm in about ¼ of the time used in the initial experiment. The production of mixed oxidants was also measured under these conditions using the DPD colorimetric method. The total concentration of mixed oxidants (the combined total of ozone, hydrogen peroxide, and dissolved oxygen) was found to be 1.6 ppm after 38 minutes of operation and 3.8 ppm after 92 minutes of operation.

EXAMPLE 2

[0048] The device used in this example for the removal of hardness from well water was a prototype consisting of a conical cylinder type reactor as shown in FIG. 2. This prototype differs from the one described in Example 1 in the configuration of the electrochemical cell, in the use of ultrasound waves to release the hardness deposits from the cathodes and in the use of a single stage filtration step. The reactor had diameter of twenty inches, an overall height of thirty (30) inches and a capacity of thirty US gallons.

[0049] The electrochemical cell consisted of six platinum rod electrodes each measuring twenty-four inches long. Five electrodes were placed two centimetres apart in a circular fashion around a central electrode. The five outer electrodes were connected together to define the cathode whereas the central rod served as the anode. The anode and cathode were also two centimetres apart. Piezoelectric ultrasound transducers were connected to the cathode and actuated every second minute for a period of one minute. The ultrasound waves cleaned the cathode of hardness which then accumulated at the bottom of the conical reactor. This water was filtered using a five micron cartridge filter and returned to the reactor.

[0050] The direct current power supply was delivering a current of 8 amps and 40 volts. The water to be treated had an initial Total Hardness Concentration of 420 ppm which, according to Guidelines for Canadian Drinking Water Quality, is considered to be very hard water This test water originated from a residential artesian well to which 1 g/L of sodium bicarbonate was added in order to increase the water's conductivity and achieve a current of 8 amps. After this addition the Total Dissolved Solids (TDS) concentration of the test water was 800 ppm, which is equivalent to a conductivity of 1600 uSiemens/cm.

[0051] About 30 gallons of this well water was placed in the reactor and treated for 280 minutes under the conditions described above. The treated water had a Total Hardness Concentration of 249 ppm, representing a reduction of 41%. After 720 minutes of treatment a reduction of 64% in Total Hardness was achieved yielding a final concentration of 150 ppm.

[0052] The production of mixed oxidants was also observed. Using the DPD colorimetric method the total concentration of mixed oxidants (the combined total of ozone, hydrogen peroxide, dissolved oxygen) was found to exceed 2.2 ppm after 280 minutes of operation.

[0053] It will be understood that the above described embodiment is for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.