US2946733A

US2946733A - Water demineralizing systems

Info

Publication number: US2946733A
Application number: US703680A
Authority: US
Inventors: Joseph J Gaysowski
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1957-12-18
Filing date: 1957-12-18
Publication date: 1960-07-26
Anticipated expiration: 1977-07-26

Description

July 26, 1960 J. J. eAvsowsKl Filed Dec. 18, 1957 3 Sheets-Sheet 1 //7 v I l I N Raw Wafer 25 I 27 3/ 24- 26 /9 /3 r 2/ I 7 7 7?) Drain I if Drain 5/ 33 Cation all/lion /7 Exchange Bed. 4/ Y Deminera/ized Wafer 42 Power Currenf Responsive Relay Supply 43 60 //8 0C, 1 4 7 E Timer 45 ii/L.

lm/enfor Joseph .1. G'aysowsk/ July 26, 1960 J. J. GAYSOWSKI 7 2,946,733

WATER DEMINERALIZING SYSTEMS Filed Dec. 18, 1957 3 Sheets-Sheet 2 Cafion 8 Anion change 884 7'0 Ora/l) Dem/hem! Wafer Marginal Power //8 I! ac, /4/

Responsive Relay [wen/0r By Joseph J 'aysowskl July 26, 1960 J. J. GAYSOWSKI 2,946,733

WATER DEMINERALIZING SYSTEMS Filed Dec. 18, 1957 5 Sheets-Sheet 3 FIG 3 Exc/r. Bed.

C'L rrenf Responsive Re/ay 260 Recf/fier Inventor Joseph Gaysowsh j f l y km;

AIM.

Unite vState Patent WATER DEMINERALIZING SYSTEMS Joseph J. Gaysowski, Chicago, Ill., assignor to General Electric Company, a corporation of New York Filed Dec. 13, 1951, Ser. No. 703,680 22' Claims; or. 204-229 v The present invention relates to water demineralizing systems, and more particularly to such systems incorporating electro-demineralizing units involving both ion exchange and electrodialysis.

It is a general object of the invention to provide in a water demineralizing system of the character noted, an improved automatic arrangement for controlling the anion concentration in the anolyte in the unit and the cation concentration in the catholyte in the unit.

Another object of the invention. is to provide in an electro-demineralizing unit, a control system of the character noted that is arranged to supply fresh dilute anolyte to the anolyte chamber in the unit and fresh dilute catholyte to the catholyte chamber in the unit in response to undesirable high anion concentration in the anolyte and un-' desirable high cation concentration in the catholyte.

Another object of the invention is to provide in an electro-demineralizing unit, a control system of the character noted, wherein the supply of the fresh dilute anolyte and the supply of the'fresh dilute catholyte are effected in response to the anode-cathode current of the unit.

A further object of the invention is toprovide in an electro-demineralizing unit, an improved arrangement for supplying anolyte and catholyte thereto,- automatically and without stray electric currents exteriorly of the unit through the supply system between the anolyte and the catholyte.

A further object of the invention is to provide in an electro-demineralizing unit, an improved anolyte and catholyte supply system that involves the use of porous diaphragms in the unit.

A further object of the invention is to provide in an electro-demineralizing unit, an improved arrangement for operating the unit under substantially high water pressures.

A further object of the invention is to provide in an electro-demineralizing unit, an improved anolyte and catholyte supply system that involves a pressure equalizing chamber disposed exteriorly of the unit and arranged to insure substantially equal pressures throughout the unit including that of the anolyte in the anolyte chamber therof and that of the catholyte in the catholyte chamber thereof and that of the water in the treatment chamber thereof.

A further object of the invention is to provide in an electro-demineralizing unit, an improved anolyte and cathadditional operating features Patented July 28, 1960 1 'l'heinvention, both asto its organization and method ofoper ation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the acconi panying drawings, in which: v

Figure l is a diagrammatic illustration of a water demineralizing system incorporating an electro-demineralizing unit and provided with an electric control circuitembodying the present invention;

ment is thus subjected to the undesirable heating mentioned. Also, it has been discovered that this expenditure of electric energy is wasted as respects effecting electrodialysis in the unit and causing regeneration of the anion exchange resin'and the cation exchange resin incorporat ed in the ion exchange bed of the unit. ,Also, it is noted that'excessive catholyte concentrations result in excessive precipitate deposits being formed in the catholyte chamber, and excessive anolyte concentrations cause gas (such as chlorine) to be released in the anolyte chamber.

In accordance with the present invention, an automatic arrangement is provided for efiecting the supply of fresh diluteanolyte into the anolyte chamber of the unit and the supply of fresh dilute catholyte into the catholyte chamber of the unit in response to the undesirable high con centrations of anions in the anolyte and cations in the catholyte, as reflected by the total anode-cathode current of the unit. More particularly, the specific resistance of the anolyte decreases substantially in response to themdesirable high concentrations of anions in the anolyte and the specific resistance of the catholyte decreases substantially in response to the undesirable high concentration of cations in the catholyte, whereby the overall resistance of the unit between the anode and the cathode thereof is correspondingly decreased effecting a corresponding increase in the anode-cathode current. In the arrangement, a marginal relay is provided in series circuit relation with the anode and thecathode of the unit; whereby the latter relay is selectively operated and restored in accordance with the anode-cathode current of the unit, and is arranged correspondingly selectively to control the supply of fresh dilute anolyte to the anolyte chamber of the unit and fresh dilute catholyte to the catholyte" chamber of the unit, thereby to avoid the undesirable high anodecathode current of the unit that is largely responsible for the undesirable heating of the water undergoing treatment in the unit.

Referring now to Fig. 1 of the drawings, the dem-ineralizing system there illustrated, and embodying the features of 'the present invention, is' especially designed for home use, and essentially comprises a raw water supply pipe 11, a deminer-alized or treated water supply pipe 12; and an telectro-demineralizing unit 13. The raw water, in the raw water supply pipe 11 is under gauge pressure and is connected to the city water main, not shown; while the deminer'alized .or treated water supplypipe 1-2 is connected to thepotablewater plumbing, not shown, in the home. The rawtwater in the supplypipe 1 1 contains substantial dissolved mineral salts supplying thereto such'cations as: Ca++, M=g++, Fe++, Na- AI+++,

etc. Moreover, this raw water may be quite hard and may have a total dissolved solids content as high as about 70 grains/gallon (1200 p.p.m.), the La Grange Park, Illinois, Well water employed in certain tests discussed hereinafter having a total dissolved solids content of 64 grains/gallon (1090 ppm). In the operation of the unit 13, the raw water is .demineralized;whereby the demineralized or treated water delivered to the supply pipe 12 has a total dissolved solids content not in excess of 3 grains/gallonjSlppmJ. V v H t t V -Preferably, the unit 13 is of the fundamental construction and arrangement disclosed in. the copending application of Edgar S. Stoddard, Serial No. '6 2,202, filed'J'anuary 30, 1956, now Patent i lo, 2,966,:684fahdthe unit 13 essentially comprises atubula r outer shell "14, constituting a cathode, a tubular permeable diaphragm 15 arranged concentrically within the cathode 14 and cooperating to define art annular catholyte chamber 16 thereb etween, a tubular permeable diaphragm 17 arranged concentrically within the diaphragm 15 andcooperating therewith .to define an annula r treatment chamber 18 therebetween, and asuitableanode r19 arranged concentrically within the diaphragm 17 and cooperating therewith to define an annular anolytefchamber 20 therebetween. The elements 14, 15, Hand '19 are arranged in upstanding position; and the upper and lower ends of the

chambers

16, 18 and 20 are respectively closed by upper and'lower insulating

headers

21 and 22. The cathode 14 may be formed of steel; the diaphragms 15 and 17 maybe-formed of a suitable wood or ceramic material; the anode 19 may be formed of carbon, or platinizedmetal wire, etc., and the

headers

21 and 22 may be formed of a suitable synthetic organic resin. Also the treatment chamber 18 disposed intermediate the diaphragms 15 and '17 contains a porous ion exchange bed 23 of substantially annular form and substantially completely-filling the same. More particularly, the bed 23 is of a mixed type com-prising both cation exchange material and anion exchange material (heterogeneously mixed). Specifically, the ion exchange bed 23 accommodates the ready passage therethrough of the water undergoing treatment and essentially comprises a loosely packed mass of first discrete particles of cation exchange material (preferably a synthetic organic polymeric cation exchange resin) and of second discrete particles of anion exchange material (preferably a synthetic organic polymeric'anion exchange'resin), the two types of discrete particles mentioned being soproportioned that substantially equal cation exchange and anion exchange capacities are possessed by the bed 23, Also, it is noted that the bed 23 is sufliciently porous that raw water undergoing treatment suflers no substantial diminution of pressure passing therethrough.

More particularly, this cation exchange resin is of bead-like formation and may comprise the strong-acid resin sold by Rohm and Haas under the name Amberlite IR-lZO; and this anion exchange resin is of headlike formation and may comprise the strong-base resin sold by Rohm and Haas under the names Amberlite IRA-400 and Amberlite IRA-410. A cation exchange resin of the type specified essentially comprises a stable insoluble synthetic organic polymer, active acidic functional groups chemically bonded thereto and dissociable into free mobile cations to impart a negative charge to the polymer, and water .in gel relationship with the polymer. Similarly, an anion exchange resin of the type specified essentially comprises a stable insoluble synthetic organic polymer, active basic function al-groupsrchemically bonded thereto and dissociable into free moblie anions to impart a positive charge to the polymer, and water in gel relationship with the polymer. The active acidic functional groups attached to the associatedorganic polymer are oriented with respect to the interfaces thereof so. as to be partially or-completely dissociable in the internal gel waterinto'fixed negative ions v linked to the polymer and into mobile exchangeable positive ions; and similarly, the active basic functional groups attached to the associated organic polymer are oriented with respect to the interfaces thereof so as to be partially or completely dissociable in the internal gel water into fixed positive ions linked to the polymer and into mobile exhangeable negative ions.

Typical such polymers to which active acidic functional groups may be attached include: phenol-aldehyde resins, polystyrene-divinylbenzene copolymers, and the like; and such suitable active acidic functional groups include: -SO H, COOH, and the like; SO H being usually preferred because of its high dissociation constant. Typical such polymers to which active basic functional groups may be attached include: urea-formaldehyde resins, melamineformaldehyde resins, polyalkylene-polyamine-formaldehyde resins, and the like; and such suitable active basic functional groups include: quaternary ammonium hydroxides, amino groups, the guanidyl group, the dicyanodiamidine group, and, like organic nitrogen-containing basic groups, the quaternary ammonium hydroxide groups, the guanidine and dicyanodiamidine residue being usually preferred because of their high dissociation constants. Normally the water in 'gel relationship with the polymer should be present in an amount of at least 15% of the weight of the dry resin.

Further, the unit 13 comprises anjupstanding conduit 24 communicating with the upper portion'of the catholyte chamber 1d and terminating in a funnel 25 adapted to receive fresh catholyte, and an upstanding conduit 26 communicating with the upper portion of the anolyte chamber 20 and terminating in a funnel 27 adapted to receive fresh anolyte. Also, an upstanding conduit 28 communicates with the lower portion of the catholyte chamber 15 and is provided with an upper substantially inverted J-shaped outlet communicating with drain plumbing, not shown; and similarly, an upstanding conduit 29 communicates with the lower portion of the anolyte chamber 29 andis provided with an upper substantially inverted J-shaped outlet communicating with drain plumbing, not shown. Further, two conduits 3t} and 31 respectively communicate with the lower and upper portions of the treatment chamber 18 and are respectively connected to the inlet and to the outlet of a pump 33; whereby operation of the pump 33 effects local circulation of the water in the treatment chamber 18 downwardly therethrough and through the porous ion exchange bed 23 and into ion exchange relation therewith, the water proceeding from the lower portion of the treatment chamber 18 via the conduit 38 to the pump 33; and therefrom via the conduit 31 back to the upper portion of the treatment chamber 18; whereby the circulated water is demineralized with the corresponding degeneration of the cation exchange material and the anion exchange material in the bed 23.

In the unit 13, the raw water supply pipe 11 is directly connected to the upper portion of the treatment chamber 18; and the demineralized water supply pipe 12 is directly connected to the lower portion of the treatment chamber 18. Also the raw water supply pipe 11 is connected to two conduits 34 and 35 that are disposed above and in cooperating relation with the two

funnels

25 and 27; which conduits 34 and 35 are respectively provided with solenoid controlled

valves

36 and 37. The valve 36 isnormally biased into its closed position and when the solenoid thereof is energized, it is operated into its open position in order to supply raw water as fresh dilute catholyte via the conduit 34, the funnel Z5 and the conduit 24 into the 'catholyte chamber 16, so that catholyte therein is displaced via the conduit 28 to the drain plumbing, with the result that the concentration of the cations in the catholyte in the catholyte chamber16 is reduced. Similarly, the valve 37 is normally biased into its closed position and when the solenoid thereof is energized, it is operated intoits'open positio'n'in order to supply rawwater as fresh dilute anolyte via the conduit-35, the funnel Z7,

and the conduit 26 into the anolyte chamber 20, sothat the anolyte therein is displaced via the conduit 29 to the drain, with the result that the concentration of the anions in the anolyte in the anolyte chamber 20 is reduced.-

In passing, it is noted that it is not essential that

individual valves

36 and 37 be arranged in the respective conduits 34 and 35, as a common valve arranged in the common connection to the raw water supply pipe 11 will serve the function noted, nevertheless, the arrangement disclosed is very convenient in that it absolutely insures the proper division of the anolyte and the catholyte into the

funnels

27 and 25, as described above.

A valve- 38 is arranged in the demineralized water supply pipe 12; and when the valve 38 is opened, the demineralized water flows from the demineralized water supply pipe 12 and raw water flows from the raw water supply pipe 11 into the upper portion of the treatment chamber 23 and thence downwardly through the ion exchange bed 23 and ultimately into thedemineralized water supply pipe 12, with the result that the raw water is demineralized, as previously explained.-

Further, the system 100 comprises a source of electric power supply that may be of 118 volts, A.-C., singlephase and including two conductors 41 and 42, the conductor 41 being connected to ground potential. A rectifier 43 is provided and comprises a pair of input terminals respectively connected to the conductors 41 and 42 and a pair of output terminals respectively connected .to the grounded conductor 41 and to an ungrounded conductor 44, the conductor 44 being connected to the positive output terminal of the rectifier 43 and the grounded conductor 41 being connected to the negative output terminal of the rectifier 43. Also, a timer 45 is provided that includes an electric timer motor 46 of the synchronous type, and preferably a Telechron timer motor; which timer motor 46 selectively controls a pair of. switches 47 and 48. The switch 47 respectively terminates the conduc: tor 44 and a conductor 49; while the switch 48 respectively terminates the conductor 44 .and a conductor 50.

The pump 33 is driven by an electric drive motor 51, one

terminal of which is connected to the grounded conductor 41 and the other. terminal of which is connected to the conductor 50. The solenoids of the

valves

36 and 37 are connected in parallel relation across the grounded conductor 41 and the conductor 49. Further, the system 100 comprises a current responsiverelay 60 that is provided with a winding included in a series connection between the conductor 44 and a conductor 61 connected to the anode 19. Also, the relay 60 is provided with a contact bridging member 62 operatively associated with a pair of contacts respectively terminating the conductors 44 and 49. Finall the cathode 14 is connected to the grounded conductor 41.

In the operation of the unit 13, a direct current is supplied from the conductor 44 via the winding of the relay 60 and the conductor 61 to the anode 19; which current is further conducted through the anolyte in the anolyte chamber 20, the diaphragm 17, the water undergoing treatment in the treatment chamber 18, as wellas the ion exchange bed 23 in the treatment chamber 18, the diaphragm 15 and the catholyte in the catholyte chamber 16 to the cathode 14 and thence to the grounded conductor 41, completing the circuit across the output terminals of the rectifier 43. The magnitude of the anode-cathode current that flows in the above-traced circuit is dependent upon the total resistance of the unit 13 between the anode 19 and the cathode 14; and at this point, it may be assumed that the current mentioned is modest so that the relay 60 remains in its restored position, the relay-60 being of the marginal type. 7

As time proceeds, the resin bed 23 is regenerated, with the result that the sorbed cations of the mineral salts are exchanged forhydrogen ions with the migration ofthe cations of the mineral salts through the diaphragm 15 into the catholyte in the catholyte chamber 16 so. that H the cation concentration in the catholyte is increased, and

with the resultthat the .sorbed anions of the mineral salts are exchanged for hydroxyl ions with the migration of the anions of the mineral salts through the diaphragm '17 into the anolyte in the anolyte chamber 20 so that the anion concentration in the anolyte is increased. As the cation concentration in the catholyte is increased, the specific resistance of this portion of the path between the anode 19 and the cathode 14 is reduced; and likewise, as the anion concentration in the anolyte is increased, the specific resistance of this portion of the path between the anode 19 and the cathode 14 is reduced; whereby the overall resistance of the unit 13 between the anode 19 and the cathode 14 is progressively reduced, with the result that the anode-cathode current is progressively increased.

Ultimately, when the anode-cathode current reaches a predetermined value, the winding of the relay 30 is sufficiently energized that the latter relay operates, whereby the contact bridging member 62 connects the conductor 44 to the conductor 49, with the result that the solenoids of the

valves

36 and 37 are energized in parallel relation causing the

valves

36 and 37 to be operated into their open positions. Thus fresh catholyte is supplied into the catholyte chamber 16 with the resulting dilution of the cation concentration therein, and fresh anolyte is supplied into the anolyte chamber 20 with the resulting dilution of the anion concentration therein; whereby the specific resistance of the catholyte and the specific resistance'of the anolyte are both increased, with a corresponding reduction in the anode-cathode current. Ultimately, the resistance of the unit 13 between the anode 19 and the cathode 14 is increased sutficiently that the anodecathode current is reduced sufficiently that the relay 6i restores, so that the contact bridging member 62 opens the previously tracedci'rcuit for energizing in parallel the solenoids of the

valves

36 and 37. Accordingly,.the

valves

36 and 37 are reclosed cutting off the supply of fresh catholyte intothe catholyte chamber 16 and the supply of fresh anolyte into the anolyte chamber 20.

Also in the operation of the system, the timer 45 periodically closes and thenreopens the switch 47 thereby periodically completing an alternative connection between the conductors 44 and 49 with the result that the

valves

36 and 37 are opened during the completion of the connection in the manner previously explained.

At this point, 'it is noted that the provision of the switch 47 in the timer 45 is altogether alternative with respect to the provision of the current responsive relay 60; whereby the switch 47 in the timer 46 may be omitted, if desired; However, the arrangement of the switch 47 in the timer 45 in the control system is advantageous as it in effect anticipates the expected future operation of the relay 60, thereby minimizing the number of operations of the relay 60 during a protracted time interval.

Also during the operation of the system, the timer 45 intermittently closes and reopens the set of switch springs 48, thereby effecting corresponding intermittent operation of the electric drive motor 51, whereby the pump 33 is correspondingly intermittently operated; More particularly, the pump 33 is operated so that the water in the treatment chamber 18 is circulated therethrough at a relatively low overall rate, the water in the treatment chamber being changed about once per hour.

In a constructional example of the water d'emineralizing unit 13, the external diameter of the diaphragm 17 was 4"; the internal diameter of the diaphragm 15 was about 12''; the internal diameter of the cathode 14 was about 16"; the height of the treatment chamber 18' between the

headers

21 and 22 Was about 36"; and the thickness of the treatment chamber 18 between the diaphragms 17 and 15 was about 4". The volume 'of the treatment chamber 18 was about 2.1 cu. ft.; the water pressure in the treatment chamber was not in excess of 45. p.s.i.;. and

the power consumptionat 60 to volts D.- C. wasin bed 23 was arranged substantially completely to fill the treatment chamber 18; whereby it had a volume of about 2.1 cu. ft. and was composed of substantially equal volurnes of the cation exchange resin Amberlite IR- 120 and of the anion exchange resin Amberlite IRA-410; the pump 33was arranged to circulate water at a rate in the general range 1 to 6 gallons/hour; and the water employed in the test was La Grange Park, Illinois, well water. In the operation of the unit 13, this raw water having a total dissolved solids content of 64 grains/ gallon was demineralized to produce treated water having a total dissolved solids content not in excess of 3 grains/ gallon.

In a test of this embodiment of the system 1%, and with the switch 47 blocked in its open position, a drawoir' of 10 gallons of demineralized water was made from the demineralized water supply pipe 12, with the corresponding supply of 10 gallons of the La Grange Park, Illinois, well waterfront the raw water supply pipe 11 into the treatment chamber 18. During the draw-oft, the relay 6t) operated automatically; and at the time of operation of the relay 60, it was observed: the anodecathode current was 8.1 amperes D.-C.; the pH of the anolyte was 1.7 and had a temperature of 60 C.; the pH of the catholyte was 12.5 and had a temperature of 42 C.; and the temperature of the treated water in the draw-oil was 44 C. When the relay 69 operated, the La Grange Park, Illinois, well water was supplied from the raw water supply pipe 11 in substantially equal amounts as catholyte into the catholyte chamber 16 and as anolyte into the anolyte chamber 20, with the result that the relay 611 restored after about 18 minutes. 01 course, the draw-off took place in a time interval of about 2 minutes, and during the time interval of 18 minutes 4% gallons of the La Grange Park, Illinois,

' well water was supplied substantially equally to the

chambers

16 and 20. At this time, and upon restoration of the relayfit), it was observed that the anodecathode current had declined to 4.3 amperes D.-C.; the pH of the anolyte was increased to 2.3 and the temperature thereof was reduced to 40 C.; the pH of the catholyte was reduced to 12.4 and the temperature thereof was reduced to 40 C. The combined anolyte displaced -from the anolyte chamber 20 and the catholyte displaced from the catholyte chamber 16 was caught and was found to have a volume of 4% gallons; and the pH of the mixture of the anolyte and the catholyte was 12.0.

Operation of the system 161) was continued, and about 2 /2 hours later, the anode-cathode current had declined to 2.9 amperes D.-C.; and another 10 gallon draw-bit was made :from the demineralized water supply pipe 12 with the result that the anode-cathode current increased to 4.3 amperes at the conclusion of this draw-oil. This magnitude of the anode-cathode current was not effective to bring about operation of the relay 60 as it was of the marginal type, as previously noted.

In a protracted and continuous run of the system 1111) without the draw-01f of any dernineralized water therefrom and involving a time interval of about 12 days, it was established that the anode-cathode current did not become excessive by virtue of the automatic intermittent operation of the relay 60 as previously explained. During this protracted run, the daily energy consumption of the unit 13 averaged 2.7 kw] hr. at 30 volts D-C. applied between the anode 19 and the cathode 14.

By way of contrast, it is pointed out that in the absence of the current responsive relay 6% and without control of the supply of fresh anolyte and fresh catholyte to the unit 13, it is not'feasible to permit unattended operation of the unit 13, since the anode-cathode current can progressively increase and ultimately reach a value substantially in excess of -12 amperes D.-C. in about 24 hoursof operation of the unit 13 with damage to the rectifier 43.

'Referring now to Fig. 2 01 the drawings, the demineralizing system 2011 there illustrated is fundamentally of the same construction as the system shown in Fig. 1; whereby corresponding reference characters have been employed therein to identify corresponding elements. Accordingly, the unit 113 comprises the anode 119, the cathode 114, the two diaphragms 115 and 117 and the mixed resinnbed 123, as well as the three

chambers

116, 118 and 121), as previously described. In this arrangement or the unit 113, the catholyte in the catholyte chamber 116 and the anolyte in the anolyte chamber are under pressure, and substantially at the same pressure as the Water in the treatment chamber 118; which result is achieved by forming the diaphra grns 115 and 117 of suitable ceramic or wood material that is not only permeable but also sufliciently porous that the water undergoing treatment in the treatment chamber 118 can penetrate the diaphragms 115 and 117 and thus supply catholyte into the corresponding catholyte chamber 116 and anolyte into the corresponding anolyte chamber 120.

More particularly, in this arrangement of the unit 113, a solenoid controlled valve 136 (corresponding in general function to the valve 36 of the system 100) is arranged in the conduit 128 communicating with the lower portion of the catholyte chamber 116; and similarly, a solenoid controlled valve (corresponding in general function to the valve 35 of the system 1110) is arranged in the conduit 129 communicating with the lower portion of the anolyte chamber 121 Also a float valve is arranged in the conduit v124 communicating with the upper portion of the catholyte chamber 116, and afloat valve is arranged in the conduit 126 communicating with the upper portion of the anolyte chamber 120. The float valve 1811 includes a casing containing a float proper 181 that is adapted to float upon catholyte in the associated casing so as normally to close an associated valve seat communicating via a conduit 182 that communicates with a casing 183 containing catalytic material 184, the casing 183 further communicating with the atmosphere. The float valve 185 includes a casing containing a float proper 186 that is adapted to float upon anolyte in the associated casing so as normally to close an associated valve seat communicating via a conduit 187 with the atmosphere.

In the operation of the unit 113, when the

valves

135 and 136 are opened, anolyte and catholyte proceed from the respective anolyte chamber 1211 and catholyte chamber '116 to drain, with the resulting reduction in pressure in the two chambers 12% and 116. When the pressure of the anolyte in the anolyte chamber 126 is thus reduced, treated water in the treatment chamber 118 proceeds through the associated porous diaphragm 117 into the anolyte chamber 120, thereby diluting the concentration of anions in the anolyte and again filling the anolyte chamber 121) so as to restore the pressure of the anolyte therein. Similarly, when the pressure of the catholyte in the catholyte chamber 116 is thus reduced, treated water in the treatment chamber 118 proceeds through the associated porous diaphragm 115 into the catholyte chamber 1116, thereby diluting the concentration of cations in the catholyte and again filling the catholyte chamber 116 so as to restore the pressure of the catholyte therein.

Of course, when anolyte is withdrawn from the anolyte chamber 120, as described above, the anolyte level therein falls so .that the float 186 opens its associated valve seat with the result that the anolyte chamber 121) is placed in communication with the atmosphere. On the other hand, when the supply of anolyte into the anolyte chamber 120 is restored, it rises through the conduit 126 into. the casing of the float valve 185 returning the float 186 into closed position with its associated valve seat so as to cutofi .the communication between the casing of the float valve 185 and the atmosphere. It will also be understood that this arrangement permits the escape of oxygen and other gaseous products that may accumulatein the anolyte in, the operation ofthe unit 113, since such gaseous products will rise into the casing of the float valve 185 causing the float proper 186 to move into its open position with its associated valve seat with the resulting venting ofthe gaseous products intolthe atmosphere. This venting of the gas from the anolyte chamber 120 reduces the pressure therein so as-to prevent the backflow of anolyte therefrom through the diaphragm 117 into the treatment chamber 118 and into contact with the resin bed 123. Thus, make-up liquid is required to fill the anolyte chamber 120 completely, as a result of the action of the float valve 185.

I Of course, when catholyte is withdrawn from the catholyte chamber 116, as described above, the catholyte level therein falls so that the float 181 opens its associated valve seat with the result that the catholyte chamber 116 is placed in communication with the atmosphere. On the other hand, when the supply of catholyte into the catholyte chamber 116 is restored, it rises through the conduit 124 into the casing of the float valve 180 returning the float 181 into its closed position with its associated valveseat so as to cut-ofi the communication between the casing of the float valve 180 and the atmosphere. It will also be understood that this arrangement permits the escape of hydrogen that may accumulate in the catholyte in the operation of the unit 113, since such gaseous'product will rise into the casing of the float valve 180 causing the float proper 181 to move into its open position with its associated valve seat with the resulting venting of the gaseous hydrogen into the casing 183. This venting of the gas from the catholyte chamber 116 reduces the pressure therein so as to prevent the backflow of catholyte therefrom through the diaphragm 115 into the treatment chamber 118 and into contact with the resin bed 123. .Thus, make-up liquid is required to fill the catholyte chamber 116 completely,as a result of the action of the float valve 180.

As previously noted, the casing 183 contains the charge of catalyst 184 that may essentially comprise platinum beads so as to bring about a water-producing reaction between the hydrogen escaping from the casing of the float valve 180 and atmospheric oxygen. Thewater thusproduced drains from the casing 183 back into the conduit 182 so that it may ultimately be drained back into the casing of the float valve 180 incident'to the next operation thereof into its open position; whereby the water thus produced is returned to the catholyte chamber 116.

The fundamental mode of operation of the unit 113 is the same as that previously described in conjunction with the unit 13, whereby it will be understood that the relay 160 operates and restores in response to respective high and low concentrations of the anions in the anolyte and of the cations in the catholyte correspondingly controlling the solenoids of the

valves

135 and 136 so as to govern the supply of fresh anolyte into the anolyte chamber 120 and the supply of fresh catholyte into the catholyte chamber 116; all in the manner previously described for the purpose explained in conjunction with the system 100. v

Referring now to Fig. 3 of the drawings, the demineralizing system 300 there illustrated is fundamentally the same construction as the system 100 shown in Fig. 1, but incorporate certain features of the system 200 of Fig., 2; whereby corresponding reference characters have been employed therein to identify corresponding elements. Accordingly, the unit 213 comprises the anode 219, the cathode 214, the two

diaphragms

215 and 217 and the mixed resin bed 223, as well as the three

chambers

216, 218 and 220, as previously described. In this arrangement of the unit 213, the catholyte in the catholyte chamber 216 and the anolyte in the anolyte chamber 220 are under pressure, and substantially at thesame pressure as the water in the treatment chamber 218; which result is achieved by the ultilization of a catholyte-anolyte supply tank 293 formed of insulating material and mutually connected to the raw water supply pipe 211 and to the catholyte chamber 216 and to the anolyte chamber 220.

More particularly, an upstanding conduit 291 projects through the bottom header 222 and communicates with the upper portion of the catholyte chamber 216; and similarly, a conduit 292 projects through the bottom header 222 and communicates with the upper portion of the anolyte chamber 220. The supply tank 293 may be formed of a suitable molded organic resin and comprises structure defining therein a central compartment 294, two laterally disposed adjacent end compartments 295 and 296 and a communicating common overhead space 297. The central compartment 294 is connected directly to the raw Water supply pipe 211, while the end compartments 295 and 296 are respectively connected to the outer extremities of the

conduits

291 and 292; and finally a body or charge of pressure-transmitting electrical-insulating liquid 297 is arranged in the common space 297 in contact with the liquids respectively arranged in the

compartments

294, 295 and 296. More particularly, the body of insulating liquid 297' may essentially comprise a light mineral oil; and specifically, the body or charge 297' comprises an insulating liquid that is incompressible and that has a specific gravity that is lower than that of water and that is immiscible with water and that serves to insulate from each other the bodies or pools of water in the

respective compartments

294, 295 and 296. Finally, the overhead space 297 in the supply tank 293 is connected by a conduit 298 with the atmosphere; which conduit 298 includes a normally closed valve 299.

In this arrangement of the unit 213, the

diaphragms

215 and 217 are formed of suitable material such as wood veneer or thin ceramic, that is permeable, but not porous; which diaphragms 215 and 217 are entirely commensurate in construction with the diaphragms 15 and 17 of the unit 13, as distinguished from the diaphragms and 117 of the unit 113 that are also porous. Furthermore, in the unit 213, the

conduits

228 and 229 respectively communicating with the lower portions of the

chambers

216 and 200 respectively include the solenoid controlled valves 236 and 235; while the

conduits

224 and 226 respectively communicating with the upper portions of the

chamber

216 and 200 respectively include the float valves 28!) and 285.

Considering now the general mode of operation of the system390, it will be under-stood that raw water under pressure is supplied from the raw water supply pipe 211 into the treatment chamber 218 in the unit 213, and also into the compartment 294 in the tank 293. The raw water supplied to the treatment chamber 218 proceeds downwardly through the ion exchange bed 223, wherein it is demineralized, in the manner previously explained, and is ultimately supplied into the demineralized water supply pipe 212. Also the raw Water under pressure in the central compartment 294 of the tank 293 exerts pressure upon the insulating liquid 297'; whereby the insulating liquid 297 exerts pressure upon the body of catholyte'contained in the compartment 295 and upon the body of anolyte contained in the compartment 296. Accordingly, the pressure is exerted between the catholyte in the compartment 295 of the tank 293 and the body of catholyte contained in the catholyte chamber 216 of the unit 213, via the conduit 291; and likewise the pressure is exerted between the anolyte in the compartment 296 of the tank 293 and the body of'anolyte contained in the anolyte chamber 220 of the unit 213, via the conduit 292. When the valve 235 is opened, anolyte from the anolyte chamber 220 is conducted to the exterior so that anolyte from the compartment 296 in the tank 293 proceeds through the conduit 292 into the anolyte chamher 220 with. the result that the anolyte in the'anolyte chamber 229 is diluted with respect to the anions therein for the purpose previously explained. Similarly, when the valve 236 is opened, catholyte from the catholyte chamber 216 is conducted to the exterior so that catholyte from the compartment 295 in the tank 233 proceeds through the conduit 291 into the catholyte chamber 216 with the result that the catholyte in the catholyte chamber 216 is diluted with respect to the cations therein for the purpose previously explained. When anolyte is .conducted from the compartment 296 in the tank 293, the pressure therein is momentarily reduced causing lie water in the central compartment 294 to overflow the associated structure and spill into the compartment 296 by virtue of the pressure in the raw water supply pipe 211; which raw water thus supplied to the compartment 294 from the raw water supply pipe 211 proceeds through the body of insulating liquid 2,97, thereby maintaining the pool of raw water in the compartment 294 in insulating relation with respect to the pool of anolyte in the compartment 2%, while supplying the raw water from the compartment 294 as anolyte into the compartment 296. When anolyte is conducted from the compartment 295 in the tank 293, the pressure therein is momentarily reduced causing the Water in the central compartment 2% to overflow the associated structure and spill into the compartment 295 by virtue of the pressure in the raw water supply pipe 211; which raw Water supplied to the compartment 294 from the raw Water supply pipe 211 proceeds through the body of insulating liquid 297, thereby maintaining the pool of raw water in the compartment 294 in insulating relation with respect to the pool of catholyte in the compartment 295, while supplying the raw water from the compartment 294 as catholyte into the compartment 295.

Hence, the tank 293 serves the function of supplying anolyte to the anolyte chamber 220 and catholyte to the catholyte chamber 216 from the raw water supply pipe 211, without electrical conduction between the anolyte and the catholyte in the tank 293, and while maintaining the pressure of the anolyte and the catholyte substantially at the pressure of the raw water in the raw Water supply pipe 211 and consequently at the pressure of the water undergoing treatment in the chamber 218; whereby there is no substantial pressure differential across either of the

diaphragms

215 or 217 in the operation of the system 300.

Also it will be appreciated that the arrangement of the valve 299 in the conduit 298 accommodates initial charging of the insulating liquid 297' into the overhead space 297 in the tank 293, as well as the removal of air or other gases from time to time, as they may accumulate in the upper portion of the tank 293.

The fundamental mode of operation of the unit 213 is the same as that previously described in conjunction with the unit 13; whereby it will be understood that the relay 260 operates and restores in response to respective high and low concentration of the anions in the anolyte and of the cations in the catholyte correspondingly controlling the solenoids of the valves 235 and 236 so as to govern the supply of 'fresh anolyte intorthe anolyte chamber 220 and the supply of fresh catholyte into the catholyte chamber 216; all in the manner previously described for the purpose explained in conjunction with the system 106.

In view of the foregoing, it is apparent that there has been provided a water demineralizing system, incorporating an electro-demineralizing unit involving both ion exchange and electrodialysis, and comprising an automatic control. arrangement for supplying fresh anolyte and fresh catholyte to the unit as required, so as to maintain the anode-cathode current of the unit within the proper operating current range thereof.

While there has been described what is at present considered .to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended I2 claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In a water demineralizing system: a demineralizing unit including structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, and a porous ion exchange bed arranged in said treatment chamber and characterized by both cation exchange and anion exchange; an inlet pipe adapted to contain raw water under pressure and connected to said treatment chamber; an outlet pipe adapted to contain demineralized water under pressure and connected to said treatment chamber; valve mechanism for controlling the flow of water from said inlet pipe through said treatment chamber and into contact with said ion exchange bcd and thence through said outlet pipe with the result that the raw water passing through said treatment chamber is demineralized and said ion exchange bed is correspondingly degenerated; first conduit means for supplying fresh anolyte into said anolyte chamber; second conduit means for supplying fresh catholyte into said catholyte chamber; a power circuit for conducting a direct current from said anode to said cathode, whereby said ion exchange bed is regenerated with the migration of the sorbed anions and cations of the mineral salts respectively into said anolyte and into said catholyte with the result that the ion concentrations therein are increased; valve apparatus for controlling the supply of fresh anolyte from said first conduit means into said anolyte chamber and the supply of fresh catholyte from said second conduit means into said catholyte chamber; and automatic means governed by the ion concentrations in said anolyte and in said catholyte for selectively controlling said valve apparatus, so that said valve apparatus is opened in response to relatively high concentrations of ions in said anolyte and in said catholyte and is closed in response to relatively low concentrations of ions in said anolyte and in said catholyte.

2. The system set forth in claim 1, wherein said bed comprises synthetic organic polymeric cation exchange resin and synthetic organic polymeric anion exchange resm.

3. In a water demineralizing system: a demineralizing unit including structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first diaphragm as a common Wall between said treat-ment chamber and said anolyte chamber and with a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, and a porous ion exchange bed arranged in said treatment chamber and characterized by both cation exchange and anion exchange; an inlet pipe adapted to contain raw water under pressure and connected to said treatment chamber; an outlet pipe adapted to contain demineralized water under pressure and connected to said treatment chamber; valve mechanism for controlling the flow of water from said inlet pipe through said treatment chamber and into contact with said ion exchange bed and thence from said outlet pipe with the result that the raw water passing through said treatment chamber is demineralized and said ion exchange bed is correspondingly degenerated; first conduit means for supplying fresh anolyte into said anolyte chamber; second conduit means for supplying fresh catholyte into said catholyte chamber; a power circuit for conducting, a direct current from said anode to said cathode, whereby said ion exchange bed is; regenerated withflthe migration of the sorbed anions and cations .of the minerai salts respectively into said anolyte and into said oath:-

olyte with the result that the specific resistance f; said power circuit between said' anode and said cathode is reduced; valve apparatus for controlling the supply of fresh anolyte from said first conduit means into said anolyte chamber and the supply of fresh catholyte from said second conduit means into said catholyte chamber; and automatic means governed by the specific resistance of said power circuit between said anode and said cathode for selectively controlling said valve apparatus, so that said valve apparatus is opened in response to a relatively low specific resistance of said power circuit and is closed in response to a relatively high specific resistance of said power circuit.

4. In a water demineralizing system: a demineralizing unit including structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber and a porous ion exchange bed arranged in said treatment chamber and characterized by both cation exchange and anion exchange; an inlet pipe adapted to contain raw water under pressure and connected to said treatment chamber; an outlet pipe adapted to contain demineralized water under pressure and connected to said treatment chamber; valve mechanism for controlling the flow of Water from said inlet pipe through said treatment chamber and into contact with said ion exchange bed and thence from said outlet pipe with the result that the raw water passing through said treatrhent chamber is demineralized and said ion exchange bed is correspondingly degenerated; first conduit means for supplying fresh anolyte into said anolyte chamber; second conduit means for supplying fresh catholyte into said catholyte chamber; means for conducting a direct current from said anode to said cathode, whereby said ion exchange bed is regenerated with the migration of the sorbed anions and cations of the mineral salts respectively into said anolyte and into said catholyte; valve apparatus for controlling the supply of fresh anolyte from said first conduit means into said anolyte chamber and the supply of fresh catholyte from said second conduit means into said catholyte chamber; and automatic means governed by said anode-cathode current for selectively controlling said valve apparatus, so that said valve apparatus is opened in response to a relatively large anode-cathode current and is closed in response to a relatively small anode-cathode current. a

5. The system set forth in claim 4, wherein said automatic means essentially comprises a relay provided with a Winding arranged in series circuit relation with said anode and said cathode.

6. In a water demineralizing system: a demineralizing unit including structure defining a treatment chamber and an anolyte chamber and a catholyte chamber,

with a first diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber and a porous ion exchange bed arranged in said treatment chamber and characterized by both cation exchange and anion exchange; an inlet pipe adapted to contain raw water under pressure and connected to said treatment chamber; an outlet pipe adapted to contain demineralized water under pressure and connected to said treatment chamber; valve mechanism for controlling the fiow of water from said inlet pipe through said treatment chamber and into contact with said ion exchange bed and thence from said outlet pipe with the.

result that the raw water passing through said treatment chamber isdemineralized and said ion exchange bed is correspondingly degenerated; first conduit means for supplying fresh anolyte into said anolyte chamber; second conduit means for supplying fresh catholytev into said catholyte chamber; valve apparatus for controlling the flow of fresh anolyte from said first conduit through said anolyte chamber to the exterior and the flow of fresh catholyte from said second conduit through said catholyte chamber to the exterior; a power circuit for conducting a direct current from said anode to said cathode, whereby said ion exchange bed is regenerated with the migration of the sorbed anions and cations of the mineral salts respectively into said anolyte and into said catholyte with the result that the ion concentrations therein are increased; and automatic means governed by the ion concentrations in said anolyte and in said catholyte for selectively controlling said valve apparatus, so

that said valve apparatus is opened in response to relatively high concentrations of ions in said anolyte and a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber,ta cathode in said catholyte chamber and a porous ion exchange bed arranged in said treatment chamber and characterized by both cation exchange and anion exchange; an inlet pipe adapted to contain raw Water under pressure and connected totsaid treatment chamber; an outlet pipe adapted to contain demineralized water under pressure and connected to said treatment chamber; valve mechanism for controlling the flow of demineralized water from said outlet pipe, whereby raw water is supplied from said inlet pipe into said treatment chamber and into contact with said ion exchange bed with the result that the raw water is demineralized and said ion exchange bed is correspondingly degenerated; first conduit means for supplying fresh anolyte into said anolyte chamber; second conduit means for supplying fresh catholyte into said catholyte chamber; a first valve for controlling the flow of fresh anolyte from said first conduit through said anolyte chamber to the exterior; a second valve for controlling the fresh catholyte from said second conduit through said catholyte chamber to the exterior; a power circuit for conducting a direct current from said anode to said cathode, whereby said ion exchange bed is regenerated with the migration of the sorbed 'anions and cations of the mineral salts respectively into said anolyte and into said catholyte with the result that the ion concentrations therein are increased; and automatic means governed by the ion concentrations in said anolyte and in said catholyte for selectively controlling said valves, so thatsaid valves are opened in response to relatively high concentrations of ions in said anolyte and in said catholyte and are closed in response to relatively low concentrations of ions in said anolyte and in said catholyte. i t

9. The system set forth in claim 8, wherein said first valve is arranged between said first conduit and the inlet of said anolyte chamber and said second valve-is arranged between said second conduit and the inlet of said catholyte chamber.

10. The system set forth in claim 8, wherein said first valve is arranged between the outlet of said anolyte chamber and the exterior, and said second valve is i r arranged between the outlet of said catholyte chamber and the exterior.

11. In a water dernineralizing system: a demineralizing unit including structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, and a cathode in said catholyte chamber; an inlet pipe adapted to contain raw water under pressure and connected to said treatment chamber; an outlet pipe adapted to contain demineralized Water under pressure and connected to said treatment chamber; valve mechanism for controlling the fiow of water from said inlet pipe through said treatment chamber and thence from said outlet pipe; valve apparatus for controlling the flow of raw water from said inlet pipe into said anolyte chamber and into said catholyte chamber and the flow of anolyte from said anolyte chamber to the exterior and the flow of catholyte from said catholyte chamber to the exterior; a source of DC. power; means connecting said source between said anode and said cathode; whereby a D.-C. current flows from said anode to said cathode with the result that the water in said treatment chamber is demineralized with migrations of the anions and the cations of the mineral salts respectively into said anolyte and into said catholyte, so that the ion concentrations therein are increased efiecting a corresponding increase in the anode-cathode current; and relay means governed by the amplitude of the anode-cathode current for selectively controlling said valve apparatus, so that said valve apparatus is opened in response to a relatively large 1 anode-cathode current and is closed in response to a relatively small anode-cathode current.

12. The system set forth in claim 11, wherein said relay means includes a winding arranged in series circuit relation with said anode and said cathode, said relay operating in response to a given anode-cathode current to efiect opening of said valve apparatus and restoring in response to less than said given anode-cathode current to effect closing of said valve apparatus.

13. In an electrolytic system, a unit including first structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first permeable diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second permeable diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying a first aqueous solution containing an electrolyte into said treatment chamber, closed insulating second structure defining therein three separated compartments and a connecting overhead space common to said three compartments, a supply pipe adapted to contain a second aqueous solution under pressure and containing an electrolyte, a first conduit connecting said supply pipe to a first of said compartments, a second conduit connecting a second of said compartments to said anolyte chamber, a third conduit connecting a third of said compartments to said catholyte chamber, means for applying a direct voltage between said anode and said cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of the anions and the cations therein respectively into the anolyte contained in said anolyte chamber and into the catholyte contained in said catholyte chamber, means for selectively controlling the discharge of anolyte from said anolyte chamber to the exterior and the discharge of catholyte from said catholyte chamber to the exterior, and a charge of insulating liquid arranged in said overhead space and in contact with three bodies of said second solution respectively contained in said three compartments, said charge of insulating liquid being incompressible and having a specific gravity lower than that of said second solution and being immiscible therewith and serving to insulate from each other the three bodies of said second solution respectively contained in said three compartments andiserving to transmit the pressure of the body of said second solution contained in said first compartment to the other two bodies of said second solution respectively contained in said second and third compartments, whereby the discharge of anolyte from said anolyte chamber effects the flow of said second solution from said first compartment through said charge of liquid into said second compartment and thence into said anolyte chamber and the discharge of catholyte from said catholyte chamber effects the flow of said second solution from said first compartment through said charge of liquid into said third compartment and thence into said catholyte chamber.

14-. In an electrolytic system, a unit including first structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first permeable diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second permeable diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying a first aqueous solution containing an electrolyte into said treatment chamber, closed insulating second structure defining therein three separated compartments and a connecting overhead space common to said three compartments, a supply pipe adapted to contain a second aqueous solution under pressure and containing an electrolyte, a first conduit connecting said sup-ply pipe to a first of said compartments, a second conduit connecting a second of said compartments to said anolyte chamber, a third conduit connecting a third of said compartments to said catholyte chamber, means for applying a direct voltage between said anode and said cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of the anions and the cations therein respectively into the anolyte contained in said anolyte chamber and into the catholyte contained in said catholyte chamber, so that the ion concentrations therein are increased, valve apparatus for controlling the discharge of anolyte from said anolyte chamber to the exterior and discharge of catholyte from said catholyte chamber to the exterior, automatic means governed by the ion concentrations in said anolyte and in said catholyte for selectively controlling said valve apparatus, and a charge of insulating liquid arranged in said overhead space and in contact with three bodies of said second solution respectively contained in said three compartments, said charge of insulating liquid being incompressible and having a specific gravity lower than that of said second solution and being immisicible therewith and serving to insulate from each other the three bodies of said second solution respectively contained in said three compartments and serving to transmit the pressure of the body of said second solution contained in said first compartment to the other two bodies of said second solution respectively contained in said second and third compartments, whereby the discharge of anolyte from said anolyte chamber effects the flow of said second solution from said first compartment through said charge of liquid into said second compartment and thence into said anolyte chamber and the discharge of catholyte from said catholyte chamber effects the flow of said second solution from said first compartment through said charge of liquid into said third compartment and thence into said catholyte chamber.

15. The system set forth in claim 14, wherein said valve apparatus is opened in response to relatively high concentrations of ions in said anolyte and in said catholyte and is closed in response to relatively low concentrations of ions in said anolyte and in said catholyte.

1-6. In antele ctrolytic system, a unit including structure defining a treatment chamber and ananolyte cham- 17 ber and a catholyte chamber, said structure including a first porous diaphragm as a common wall between'said treatment chamber and said anolyte chamber and a second 'porous diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying an aqueous solution containing an electrolyte into said treatment chamber under pressure, said first diaphragm being characterized by the passage of said solution therethrough from said treatment chamber into said anolyte chamber when the pressure of said solution in said treatment chamber is somewhat greater than that of the anolyte in said anolyte chamber, said second diaphragm being characterized by the passage of said solution therethrough from said treatment chamber into said catholyte chamber when the pressure of said solution in said treatment chamber is somewhat greater than that of the catholyte in said catholyte chamber, first float-valve means for controlling the venting of gas from said anolyte chamber to the exterior when said anolyte chamber contains less than substantially a complete filling of anolyte, second float-valve means for controlling the venting of gas from said catholyte chamber to the exterior when said catholyte chamber contains less than substantially a complete filling of catholyte, means for applying a direct voltage between said anode and said cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of the anions and the cations therein respectively into the anolyte contained in said anolyte chamber and into the catholyte contained in said catholyte chamber, and valve apparatus for controlling the discharge of anolyte from said anolyte chamber to the exterior and the discharge of catholyte from said catholyte chamber to the exterior, and automatic means governed by the ion concentration in said anolyte and in said catholyte for selectively controlling said valve apparatus.

17. The system set forth in claim l6, and further comprising a mass of catalyst arranged in the gas vent from said second float-valve means and characterized 'by the promotion of a water-producing reaction involvnd porous diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying an aqueous solution containing an electrolyte into said treatment chamber under pressure, said first diaphragm being characterized by the passage of said solution therethrough from said treat-;

ment chamber into said anolyte chamber when the pressure of said solution in said treatment chamber is some what greater than that of the anolyte in said anolyte chamber, said second diaphragm being characterized by the passage of said solution therethrough from said treatment chamber into said catholyte chamber when the pressure of said solution in said treatment chamber is somewhat greater than that of the catholyte in said catholyte chamber, first float-valve means for controlling the venting of gas from said anolyte chamber to the exterior when said anolyte chamber contains less than substantially a complete filling of anolyte, second float-valve means for controlling the venting of gas from said catholyte chamber to the exterior when said catholyte chamber contains less than substantially a complete filling of catholyte, means for applying a direct voltage between said anode and said cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of the anions and the cations therein respectively into the anolyte contained in said anolyte chamber andinto the catholyte contained in said catholytelchambereso that the ion concentrations therein are increased, valve 'appa-" ratus for controlling the discharge ot,.anolyte from;said

anolyte chamber tov the exterior: and the discharger of catholyte from said catholyte chamber -to, the exterior and automatic means governed by the ion concentrations in said anolyte and in said catholyte-for selectively con-f trolling said valve apparatus. a 19. The system set -forth .in.; cl

valve apparatus is opened in response to relatively high concentrations of ions in said anolyte and in said catholyte and is closed in response to relatively low concentrations of ions in said anolyte and in said catholyte.

20. In an electrolytic system, a unit including first structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first permeable diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second permeable diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying an aqueous solution containing an electrolyte into said treatment chamber under pressure, means for supplying an anolyte into said anolyte chamber under pressure, means for supplying a catholyte into said catholyte chamber under pressure,

first float-valve means for controlling the venting of gas,

means for applying a direct voltage between said anode and said cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of thc anions and the cations therein respectively into the ano-, lyte contained in said anolyte chamber and into the catholyte contained in said catholyte chamber, and valve apparatus for controlling the discharge of anolyte from said anolyte chamber to the exterior and the discharge of catholyte from said catholyte chamber to the exterior, and automatic means governed by the ion concentrations in said anolyte and in said catholyte for selectively controlling said valve apparatus.

21. In an electrolytic system, a unit including first structure defining a treatment chamber and an anolyte chamber and a catholyte chamber with a first permeable diaphragm as a common wall between said treatment chamber and said anolyte chamber and with a second permeable diaphragm as a common wall between said treatment chamber and said catholyte chamber, an anode in said anolyte chamber, a cathode in said catholyte chamber, means for supplying an aqueous solution containing an electrolyte into said treatment chamber under pressure, means for supplying an anolyte into said anosaid cathode, whereby said first aqueous solution is subjected to electrodialysis with the migration of the anions and the cations therein respectively into the anolyte contained in said anolyte chamber and into the catholyte contained in said catholyte chamber, so that the ionconcentrations therein are increased, valve apparatus for controlling the discharge of anolyte from said anolyte chamber to the exterior and the discharge of catholyte from said catholyte chamber to the exterior, and automafde means gqvemed by th ionconcemrations in said andly te and-i1 1: said eathnlyte. vfor selectively. 'conirdlling said-valv'eihpparatusb* r 22; Thes ystin 's't fdi'thdd claim 21, wherein said valve apfiffit us'fisjbpelied ih res'lionse to relatively" high coneehu gt idns bf ions insaid anolyte and in saidcatholyte and is closed in responsetorelatively low concentrationsflifdiw -in s'ai'd" anolyte and'in said catho1yte.

References Cited, in fil e of this patent UNITED STATES PATENTS w Aderer' July 27, 1915 Simsohn. A1 1g,,23,' 1 921" Gqrdo nz, May 17,1949,

Sqthard; Aug. 19,1932 f Suthard Feb. 19,1957 Pearson Nov. 5, 1957 Stoddard Mar. 4, 1958 V r/ I ;i.i imware 7 UNITED STATES PATENT OFFICE CERTHHCATE OF CORRECTHNN Patent No. 2 946 733 Joseph Jq Gaysowski July 26 1960 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 14 line 52, before "fresh" insert flow of =9 (SEAL) Attest: ERNEST W. SWIDER XXBXXXW Attes ting Oflicer I o ARTHUR w. CROCKER Actlng Commissioner of Patents

Claims

1. IN A WATER DEMINERALINZING SYSTEM: A DEMINERALIZING UNIT INCLUDING STRUCTURE DEFINING A TREATMENT CHAMBER AND AN ANOLYTE CHAMBER AND A CATHOLYTE CHAMBER WITH A FIRST DIAPHRAGM AS A COMMON WALL BETWEEN SAID TREATMENT CHAMBER AND SAID ANOLYTE CHAMBER AND WITH A SECOND DIAPHRAGM AS A COMMON WALL BETWEEN SAID TREATMENT CHAMBER AND SAID CATHOLYTE CHAMBER, AN ANODE IN SAID ANOLYTE CHAMBER, A CATHODE IN SAID CATHCLYTE CHAMBER, AND A POROUS ION EXCHANGE BED ARRANGED IN SAID TREATMENT CHAMBER AND CHARACTERIZED BY BOTH CATION EXCHANGE AND ANION EXCHANGE, AN INLET PIPE ADAPTED TO CONTAIN RAW WATER UNDER PRESSURE AND CONNECTED TO SAID TREATMENT CHAMBER, AN OUTLET PIPE ADAPTED TO CONTAIN DEMINERALIZED WATER UNDER PRESSURE AND CONNECTED TO SAID TREATMENT CHAMBER, VALVE MECHANISM FOR CONTROLLING THE FLOW OF WATER FROM SAID INLET PIPE THROUGH SAID TREAMENT CHAMBER AND INTO CONTACT WITH SAID ION EXCHANGE BED AND THENCE THOUGH SAID OULET PIPE WITH THE RESULT THAT THE RAW WATER PASSING THROUGH SAID TREATMENT CHAMBER IS DEMINERALIZED AND SAID ION EXCHANGE BED IS CORRESPONDINGLY DEGENERATED, FIRST CONDUIT MEANS FOR SUPPLYING FRESH ANOLYTE INTO SAID ANOLYTE CHAMBER, SECOND CONDUIT MEANS FOR SUPPLYING FRESH CATHOLYTE INTO SAID CATHOLYTE CHAMBER, A POWER CIRCUIT FOR CONDUCTING A DIRECT CURRENT FROM SAID ANODE TO SAID CATHODE, WHEREBY SAID ION EXCHANGE BED IS REGENERATED WITH THE MIGRATION OF THE SORBED ANIONS AND CATIONS OF THE MINERAL SALTS RESPECTIVELY INTO SAID ANOLYTE AND INTO SAID CATHOLYTE WITH THE RESULT THAT ION CONCENTRATIONS THEREIN ARE INCREASED, VALVE APPARATUS FOR CONTROLLING THE SUPPLY OF FRESH ANOLYTE FROM SAID FIRST CONDUIT MEANS INTO SAID ANOLYTE CHAMBER AND THE SUPPLY OF FRESH CATHOLYTE FROM SAID SECOND CONDUIT MEANS INTO SAID CATHOLYTE CHAMBER, AND AUTOMATIC MEANS GOVERNED BY THE ION CONCENTRATIONS IN SAID ANOLYTE AND IN SAID CATHOLYTE FOR SELECTIVELY CONTROLLING SAID VALVE APPARATUS, SO THAT SAID VALVE APPARATUS IS OPEN IN RESPONSE TO RELATIVELY HIGH CONCENTRATIONS OF IONS IN SAID ANOLYTE AND IN SAID CATHOLYTE AND IS CLOSED IN REPONSE TO RELATIVELY LOW CONCENTRATIONS OF IONS IN SAID ANOLYTE AND IN SAID CATHOLYTE.