US1001589A

US1001589A - Electrolytic cell.

Info

Publication number: US1001589A
Application number: US39706007A
Authority: US
Inventors: Henry Stafford Hatfield
Original assignee: Individual
Current assignee: Individual
Priority date: 1907-10-12
Filing date: 1907-10-12
Publication date: 1911-08-22
Anticipated expiration: 1928-08-22

Description

H. S. HATFIELD. ELECTROLYTIC CELL.

I APPLICATION FILED 0OT.12, 1907. 1,()Q1,589 Patented Aug. 22, 1911.

2 SHEETSSHBET 2.

1 II I SEEN-JUAN is to transfer the insulating substance from I be transferred.

HENRY STAFFORD HATFIELD, 0F HOVE, ENGLAND.

- ELECTROLYTIC CELL.

Specification of Letters Patent. Patented Aug. 22, 1911.

Application filed October 12, 1907. Serial No. 397,060.

To all whom 'it may concern:

Be it known that I, HENRY Srarronn HAT- FIELD, a subject of the King of Great Britain and Ireland, residing at 18 Palmeira Square, Hove, in the county of Sussex, England, have invented certain new and useful Impro nents' in Electrolytic Cells, of which the following is a specification.

The invention re ates, notto electrolytic cells in general, but to cells in which the sole result of the passage of a current is, that some substance is transferred from one part of the cell to another. Such cells I call elec-. trolytic transference cells. They are thus distinguished from other cells in'which the result of the passage of a current is to produce permanent changes in the strength or chemical nature of the electrolyte, or to liberate substances from chemical combination or both.-

Electrolytic transference cells need to be distinguished by a name from others, be cause they have quite special applications andadvantages for these applications. The

substance transferred from one part of the cell to another may be thereby rendered morepure, as in the case of the copper rcfining cell. Im ure copper serves as anode;

only copper, an not impurities, is transferred to the cathode by theaction of the current. Again, they are used for'mcasuring pur; poses, as in the W'right mercury meter. The substance after transference always appears on one-electrode; and before my invention,

the mass of substance to be transferred formed the other electrode, or a part of it. No other way of feeding the substance into the electrolyte continuously as the deposition took place at the other electrode was known, and hence a number of substances, such as bromin, which are insulators and cannot therefore be used as electrodes, could not by any known means be electrolytically transferred.

My invention consists'chiefiy in the use of arr-electrolyte, which can dissolve, and is saturated with, an insulating substance to Such electrolytes can be formed to suit many substances never hitherto transferred electrolytically. Further in common with all electrolytic transference cells my electrolyte is not permanently altered in composition bythe passage of the current; the net and sole result of the latter one part of the cell to another by rendering I it-temporarily unsaturated with respectto the insulating substance at one electrode.

As hereinbefore indicated, my invention relates to electrolytic cells of that type in which insulating substances are deposited. Previously to 'my invention only one instance of this type was known and it differs widely from the cells of my invention. For con-. venience I group all cells underthetype above mentioned into two classes, one of;

which constitutes my present invention and the other of which embraces the cell previ-' ously known. In both classes a compound of. the body to be deposited forms a constituent of the electrolyte. This compound ls-decomposed by the electric current. At

one-electrode (hereinafter called the first electrode) the body is deposited; at the other electrode (hereinafter called the second .elclctrode) a compound of the body to be deposited is reformed.

In the already known class the second electrode is formed of aconducting' body capable of dissolving the body to be deposited or uniting with it, and this electrode is placed in contact with a reserve supply of the body to be deposited, so that it may always be saturated therewith. At this electrode, the compound decomposed is reformed, a supply of the body to be deposited being .derivcd from the electrode, and, through the latter, from the reserve supply. It may be said of this known class, that the second electrodeis depolarized by the body to be deposited which is contained in it.

In the class which constitutes my present invention, (hereinafter termed the depolarizing electrolyte class) it is not necessary for the working of the cell that the second electrode should have the power of dissolving the body to be deposited or of uniting withit, and the said electrode need not be in contact with the reserve supply of the body to be deposited. By my invention, the electrolyte is capable of dissolving the body to be deposited and is saturated therewith through being in contar" with a reserve supply of the said body. At the second electrode thecompound decomposed or one similar to it but containing less of the body to be deposited is reformed. the supply of the body to be deposited bringdcrin-d not from the second electrode but directly from the I again saturate it.

' I may arrange to hermetically seal the and further, that when the electrolyte has been unsaturated by abstraction of the deposited body, contact with the latter will cell, and pivot it so that by turning it the depositedbody may be returned to the reservoir from which the'solution at the sec: ond electrode is regenerated; If the body to be depositedbe aliquid I may usea self-' emptying siphon to measure it and give a multiple dial effect, as employed in the measurementof mercury by Wright, Patent No. 702,844, dated 17th June, 1902. Or .I

may: cause the liquid or gas deposited to flow into a. number of tubes-so, arranged that when'one isfull the next thereto will receive the liquid or-gas. V

In order that'lny invention may be more readily understood,. I shallfnow" roceed to describe it withreference to tie accom panyingsheet-of drawings in which,

Figiire 1 is an end elevation of the cell constituting a meter as aforesaid; Fig. 2 is a side elevation'thereof; and Fig. 3 a section on'the line a,-b of Fig. 1'; Fig. 4 shows another "house service meter which diifers from that shown in Figs; -1, 2 and. 3 in that instead of a liquid being deposited at gas is deposited; Fig. 5 shows an electrolytic cell in which the body to be deposited is a solid Fig. 6 illustrates a case in which a liquid or solid is deposited but in which the electrical resistance of the cell is arranged to he as low as possible; 7 illustrates a cell designed for the purification of a gas by elcetro-deposition; and Fig. 8 illustrates a modifiediorm of cell for purifying gas by electro-deposition.

Referring now to I igs. 1,2 and 3, the cell S is of glass divided by the partition H into two parts. -The electrolyte is a dilute solution of hydro-bromic acid saturated with bromin. A pool of bromin 0 lies on the bottom of the cell; in the right-hand compart-merit E itis at a higher level and passes into the left hand compartment and keeps the level of the pool there constant through a hole at F. The cathode B consists of an iridium plate close above the surface of the bromin. The anode A is of platinum and is placed in a'funnel ending in a reading tube 1) (Figs. 1 and 3) which is formed as a self-emptying siphon. IVhen current is passed between the electrodes A (in this case the positive electrode) and I5 bromin is deposited on A. and slnce the solution is already saturatedwith 'bromin the latter drops -froin. the electrode A into the ncas uring tube D. At the electrode B hydrobromic acid is formed by the combination ofthe hydrogen (there released) with the greater part of the current passingthrough low resistance Gris placed in parallel thethis low resistance. "The cell is pivoted S0 that it can be inverted to return the bromin' to the reservoir after-a manner well known, in connection with'mercury electrolytic 1neters. The high resistance is constructed partially of a pure metal such as;1roi'1hav' mg a large positive temperature co efiicie'nt' and partially of a suitable resistance? alloy such as-manganin. The ro ortionof the two metals is such that the whole circuit shall have an approximately constant resistance with change of temperature.

In Fig. at, I illustrate a meter which differs from that previously described in that it is adapted for the measurement of a gas" measurement of a liquid so liberated. The gas designed to be liberated inthe specific liberated by the current instead of the f case now under description is chlorin so that this gaswill be deposited as" in the'former case at the anode, A. The electrolyte employed is a solution of ferric chldrid saturatcd 'with chlorin of which there is a' re-' serve supply in the space C. The chlorin liberated at the anode A is collected at the upper part of the depositing tube D which so constructed as to return upon itself for pur mses of easy resetting. The equivalent of the liquid displaced in the depositing tube overflows into the tube E The elec trolyte which is converted from ferric to ferrous chlorid at the. electrode 13 by the action. of the current is reconverted by contact with the chlorin in the space C, that is to say by purely chemical action, into fcr-' ric chlorid. Measurement may be made of the amount of gas collected in the tube D and orhy measurement of the liquid displaced into the tube E. A scale such for 1 example as is shown in this figure as well as in Fig. I may be employed f r the measurement of the deposited body. I. have spoken of the gas being liberated in this case attlieanode. I do'not imply that in other cases the body to be deposited is neces: sarily liberated at the anode. It will be obvious that the electrode at which the may be introduced as it is dissolved away.

in thebath. The solid deposited on A may fall of itself into the tube E but if it does notdo so it may be periodically or continuously scraped away from the electrode. As an illustrative case I may mention the purification of sulfur. 'lh'eelectrolyte employed in this case will be a" strong solution of sulfid of sodium saturated with sulfur. \Vhile these cells exhibit the principles of my invention in its simplest form they have the drawback that the electrodes are comparatively wide apartin order that solution depleted at the second electrode shall reach the first without, being resaturated with the substance to be deposited. In the use of such cells for the purification on a commercial scale of substances this would lead to an excessive waste of electric energy in the resistance .ofthe cell. For this purpose I prefer to place the electrodes close together and by suitable, means cause a circulation of the liquid away from the first electrode over the second. The electrolyte after passing the second is then brought into contact wit-h substance and saturated, fin; lly returning to its starting position. Two such constructions are figured diagrammatically in Figs. 6 and 7. In Fig. (3 which is suited particularly for purifying a liquid or a solid the two electrodes are placed close together at A and B and a circulation is maintained by a pump D in the direction shown by the airows. In the con'ipartment C the liquid or soli(l.i-' brought into thorough contact with the substance which is to be dissolved and which lies in a pool or mass at the bottom of the said compartment. The electrodes are pierced with holes to allow of tree circulation of liquid througlrthem.

Fig. 7 illustrates a cell which is adapted f relect-ro-dtposition or gas by deriving it from a mixture with other gases. The electrolytc is contained in the cell A. it. ll, F, the first electrode. on which gas is deposited. being the electrode A. and the second electrode 15. The first el ctrode A. is formed in parallel bars on a grating so that the gas which is deposited at its under side can easily escape upward. Electrode l, is porous and the liquid gradually periolatcs through it falling on trays in the absorption chamer through this absorption chamber the impure or mixed gas from which the gas to be deposited has to be separated, is passed. The electrolyte on reaching the bottom of this chamber is restored to the upper part of the cell by a pump at F. At the electrode B the electrolyte becomes unsaturated with respect to the gas to'be deposited and in passing down the absorption chamber becomes resaturated therewith. This apparatus will not be eflieient as applied to the deposition of a gas such as chlorin, the solubility of which in most electrolytes varies considerably with the pressure. If the cell in Fig.7 were used for the deposit-ion of chlorin the liquid being saturated with chlorin atatmospheric pressure. by contact with the electrode A would lose a certain amount of free chlorin by the action of the electrode B and in passing through the absorption chamber CT in which the gas con-' tains chlorin at a lower partial pressure than the atmospheric would not be resaturated here to the strength correspondin to atmospheric pressure. In Fig. 8 this di ficulty is avoided because the gas-absorption chamber D is connected with the cellby a long pipe F, the other details being similar to Fig. 7. It is then possible to either increase the pressure in D above the atmospheric by the amount corresponding to the head of liquid in the pipe 1*,or to decrease the pressure above the cell at the top of F 8 by a corresponding amount. The condition to be fulfilled is that the pressure of the pure gas on the liquid near the-electrode at which it is given off should be equal to or less than thepartial pressure of this "as in the mixed gases in D.

1. An electrolytic transference, cell consisting of an electrolyte in which any insu lating substance deposited b the passage of the current through the cell is soluble and with which it is saturated; two electrodes on one of which the insulatin substance is deposited and at the other 0 which the electrolyte becomes unsaturated with respect to the substance deposited without perma- 1 nent alteration of the electrolyte; and a Supply of the insulating substance deposited r esaturating by contact therewith the liquid which has become unsaturated, the sole result being to transfer the insulating sub- 1 stance from one part of the cell to another, substantially as described.

An electrolytic transference cell consisting of an electrolyte'in which any insulating substancedeposited by the passage of the current through the cell is soluble and. with which it is satul'attd; twoelectrodes on one of which the insulating substance is deposited and at the other of which the electrolyte becomes unsaturated with respect to the substance deposited without per manent alteration of the electrolyte; a supply of the insulating substance deposited lesaturating by contact therewith the liquid whichhas become unsaturated; and a device substantially as described.

for causing the circulation of the electrolyte.

with reference to the resaturating substance,

3. An electrolytic transference cellconsistingof an electrolyte in which any substance deposited by the passage of the current through the cell is soluble;'two electrodes on oneof which the substance is de-' posited and at the other of which the,electi'olyte becomes unsaturated with respect to' the, substance deposited; an absorption chaiuber containing a'supply of the substance deposited resaturating by contact therewith the liquid which has become unsaturated; aud ahead of liquid bet-ween the electrodes and. the absorption chamber; so that the pressure oil-the electrolyte at the' electrodes may be lower than that in the abSOrptiO'n chamber, substantially as de- ;20"scribed." v

4.'An electrolytic transference cell con sisting of an electrolyte in which any substance deposited by the passageof the currentth'rough thecell is soluble; two electrodes, one of-them being porous and on one of which the substance 1s deposited and at the other of which the electrolyte-rhizomes unsaturated, with respect to the substance deposited; and a supply of the substancedeposited resaturating by contact therewith the liquid which has become unsaturated, substantially as described.

In "Witness whereof I have signed my name to this specification in the presence of. two subscribing witnesses. v

I STAFFORD HAHF IELD. Witnesses! 1 H. D. JA EsoN,

F. RAND.