US1371995A - Art of electrical precipitation - Google Patents

Description

A. F. NESBIT.

ART OF ELECTRICAL PRECIPITATION. APPLICATION FILED No.10. I920.

Papema Mar. 15,1921.

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UNITED STATES PATENT OFFICE.

ARTHUR F. NESIBIT, OF WILKINSBURG, PENNSYLVANIA.

ART OF ELECTRICAL PRECIPITATION.

To all whom it my concern:

Be it known that I, ARTHUR F. NESBIT, a citizen of the United States, and resident of \Vilkinsbur in the county of Allegheny and State of ennsylvania, have invented certain new and useful Improvements in the Art of Electrical Precipitation, of which the.

following is a specification.

This invention relates to the separation of solid or liquid particles from fluid streams by electrical precipitation, and more parmethods involves the formation of an ionization field produced by opposing electrode systems, the fields being produced in various ways and generally being in the form of discharge and collecting electrodes bet-ween which the field is produced. v

Gaseous fluids such as producer gases and by-product coke oven gases have a very high temperature and carry quantities of coal-tar and other by-products in suspension in the form of finely divided or vaporized particles of liquid and it is the object of the present invention to commercially recover the coal-tar and associated ingredients such as anthracene and naphthalene separately from the gases by reducing the finely vaporized articles of these ingredients to a denser orm by refrigeration and by subjecting them to the action of successive ionization zones and also by causing a mechanical centrifugal action.

The apparatus for accomplishing the above objects is comparatively simple in construction, cheap to manufacture, and durable, as will be readily apparent from the following specification and accompanying drawing herewith. I

Figure 1 is a sectional, somewhat diagrammatic partial side elevation of tower-shaped apparatus embodying the principles of my invention.

Fig. 2 is a continuation of the side elevation of Fig. 1 from the line XX.

Fig. 3 is a detail of a portion of one of Specification of Letters Patent. Patented M 15 1921 Application filed December 10, 1920. Serial No. 429,666.

the discharge electrodes showing the circular. discharge edges.

Fig. 4 isa similar detail View showing "a modified form of discharge electrode. Referring to the drawings, the numeral 2 indicatesa casing or shell having an insulating chamber 3 at its top, a suitable partition 4 acting-as a support for the insulators 3 etc., and the insulators 3 carrying the electrode system, which includes supporting members 5 of proper form, having a de pendlng support 6 and carrying member 7 which preferably is in the form of a spider or frame and supports or carries the dis-- charge electrodes 8 which extend centrally through tubular collecting electrodes 9.

The support 6 is a conductor and carries the charge to the discharge electrodes 8, and is provided adjacent its lower end with collars 6 having a plurality of discharge points. The points ofthe collars 6 set up a discharge from their ends, which'may be identified as an electric wind, and which will throw back any of the gases or fogs formed by the gases thereby compelling them to pass downward through the electrode system.

The discharge electrodes 8 are in the form of rods or small pipes, having several portions, each portion being of less diameter than its immediate preceding portion. The collecting electrodes 9 are likewise successively reduced in diameter to correspond with the reduced diameter of the discharge electrodes 8, thus substantially equalizing the distance between the electrodes 8 and 9 throughout the entire system, so that the resistance to the travel of the electric discharges will be substantially equalized. However, the collecting electrodes are not integral, but are formed of separate tube sections, each section being of less diameter than the preceding section and being arranged sothat the smaller section telescopes an appreciable distance within the preceding larger section, thus forming outlets or traps 10-to permit the escape of the collected mat-,

ter from the section of electrode immediately preceding or above the trap.

Transverse conical shaped partitions 11 are arranged immediately below each of the series of traps formed in the collecting electrodes and are so arranged that their conical peak is slightly below the lower edge of the traps. These artitions 11 are adapted to gather or col ectthe roduct discharged through the traps 10 the collecting electrodes. Suitable outlets or drains 11 are provided-at the bottom edge of the partitions 1.1 to allow for the removal of the separated ingredients as desired.

A partition '11 similar-in construction -and shape to the partitions 11 is arranged' slightly below the top'edge of the collecting electrodes 9and is adapted to collect any ash or dust particles which may be (118- charged over the top of the electrodes-9' due to the centrifugal action of the gases, as

they: enter the tubular electrodes '9; The

, means forcausing the centrifugal action of the gases and the release of the. dustparti point ,will .be hereinafter more cles at this fully described. a

es, as y P ss through the collecting electrode. lt 'will be understood of course, that a helical screw -1 thread may be substituted forthe circular 'ed cs 10 if desired.-

upper portion,

,tracted plurality of vanes 14 forming a plurality of uitable cooling or refrigerating jackets V gtion 4;, the space between the,. part1t1on and 12 are concentrically arranged aroundthe collecting electrodes "to cause condensation; I c J 21.;from which the gases pass into the several field s; provided by the opposing electrode ,are precipitated or of the vapors as the Plecting electrodes'and hurled against the co to generally lower the temperature'of' the gases asjthey traverse theionization'zones orm'edin the spaces between the electrodes hasa-gas outlet 23 and a" bottom discharge opening 24 closed by'bells 25 of the usual 13 is arranged around and in contact with the upper end of "each ,of the discharge secured-to the s ider 7.,

8and9. A direction imparting head or member electrodes and 1 is The members '13.

and the lowerportion is conmore or" lessand providedwith a helical passa' es. i 1

Apart of t e gases will be forced-through the helical passages formed by the vanes 14 and w ll have-a centrifugal w irling'motion' imparted thereto, and will become ionized with and consequently charged with the' Y a same signs-as the discharge electrodes The and, also become charged. The "whole remaining volume ofgases will pass around the sp der member 7 and direction imparting head rmembers 13 and pass 9 where they wil theportion that has passed volume of gas will then enter the space be- -tween the collecting and discharge elec trodes. v a

A second spider member 15 is arranged to hold the lower ends the discharge elecare funnel shape in the over the top trodes 8, and when it is desired to further subject the gases to another set of ionization zones, as is generally the case, a second serles of discharge electrodes, 16 are suspended ingvmembers 18 similar in all respects-tothe members ;13 and surrounding the discharge electrodes 16. It will of course be understood that the discharge electrodes 16 and collecting electrodes -17 are of successively smallerv diameter similar to the electrodes 8 and 9, and that'suitable traps 17 are provided .for allowing the escape of the collected fluids from the collecting electrodes. Alsothat a same purpose as the partitions 11 and drains 11f are arranged below the traps 10. Suit- :able refrigerating jackets 12 will. also hearranged to surround the collecting electrodes,

as described in the main structure.

The casing-2 isprovided-witha gas inlet arrangednbove the upper ends of the collecting "electrodes 9 and below the partithe tops of the electrodes forming a chamber -jTheispace below the electrodes, forms a collecting and discharge chamber 22f which construction. t

The ases as they enter through the inlet 20 are adened with impuritiesfprincipally in the form of vaporized coal-tar'products includin v [naphtha ene. There is alsoa certain amount of-ash particles'carriedin suspension inthe pitch and tar, anthracene and gases.

The tar and path, wing it ar'yhigh boiling point,v 'W I by the centrifugal motion of the-gases and a hurling-force of the successive ionization, zones. Therefore, the-first tubular section of collecting'electrodewill collect 'a tar vand pitch substance, which it will discharge through its trapf10.= v a f Anthracene, having'the next highest boil ing point'tothe. pitch and tar, will be the ingredient next to condense of fluid particlesof suflicient and form a fog to" be precipitated; hencethe second section size and wei htv conical partition 19 and outlets-or'drains 19 iarefarranged below the traps -17;-for the ill= be the first ngredient or Y product to condense forming a, fog ofliquid ggparticles of suflicient size tobe'precipitated' since the head vmembers 13 are connected of thedischarge' electrodes" 9. will collect an anthracene product. p v

Naphthalene, having the lowest hoilin pfinkpf the three ingredientsmentione the last to condensethe vapors,

this product and, therefore, the lower or last trap in the tubular electrodes will discharge a naphthalene product which has been gathered or collected in the collecting elec-' trodes above the last or lowermost trap.

Detailed operations of'the apparatus described, when cleaning producer and coke charged with, the same sign as the discharge electrodes, will cause an initial ionization of the gases passing therethrough. The other portion of the gases will pass around the spider member 7 and direction-imparting members or heads 13 and pass over the top of the collecting electrodes where they will commingle with the portion that has passed through the helical passages and will take on the swirling motion of that portion and alsobecome ionized since said first portion has been subjected to an ionization force.

The rotation causes the heavier particles of dust to be thrown on the outside or periphery of the gas column due to centrifugal force, and since the gases are charged with the same sign as the discharge electrodes 8, the ionization forces will aid in throwing off the dust particles before the gases, enter the ionization zone between the discharge electrodes 8 and the collecting electrodes 9. The ash particles thrown out at this stage will fall over and around the outside of the collecting electrodes and be gathered or caught on the transverse conical partition 11.

As the gases emerge from the members 13 and over the collecting electrode 9, they pass into the ionization zone between the dis charge electrodes 8 and the collecting electrodes 9, and are immediately acted upon by the force of the ionization zones. The heavier particles of liquid, which, in the case of coke oven and producer gases, will be particles of tar and pitch, are hurled or precipielectrodes 9.

ing As the. gases pass on through the first section of tubular collecting electrodes, they are radually cooled, due to the action of there rigerating jackets, and

the finer particles of tar and pitch vapors are caused to' condense, forming a fog of fluid particles, and such particles are precipitated againstthe collecting electrodes 9.

The pitch and tar product which has been precipitated against the first sections'iof collecting electrodes- 9 will flow or run downwardon the inside of the electrode and escape throu h the first series of traps 10 and be 0011601385011 the first conical partition 11, ready to be drawn ofi through the drains 11*.

The ases continue to pass downward between t e second section of the electrodes 8 and 9, and are further refrigerated causing the condensation of anthracene vapors which have a lower boiling point than the tar and.

pitch vapors, andwhich vapors will be condensed, forming a fog of'anthracene particles, and will be precipitated, by the force of the ionization zones, against the second section ofcollecting electrodes. The anthracene precipitated in these sections of collecting electrodes will fall by gravity through the traps 10 and be collected above the second conical partition 11, ready to be drawn off through the drains 11.

The gases pass on downward through the remaimng space between the electrodes 8 and 9 and a portion thereof enter the second set of direction-imparting.- -members 18, which are similar to the members 13, thus having a second whirling or centrifugal motion imparted to them, and they then pass between the second series of discharge electrodes 16 and collecting electrodes 17 The remaining gases pass around the members 18 and into the spaces between the collecting electrodes 17 and discharge electrodes 16 and 'commingle with the first named portion. A ny vapors which have been condensed during the passage of the gases through the last por tions of the electrodes 8 and 9 and through the 'heads or direction-imparting members 18 will be thrown off due to the helical swirl or centrifugal force of the gases before they enter between the electrodes 16 and 17. Thisliquid, when coke oven and producer gases are being treated, will be naphthalene and will be thrown over and around the collect- I ing electrodes 17 and fallby gravity onto the last or lowermost conical partition 19. The body of gases will, continue their course downward into spaces between the electrodes 16 and 17 and be subjected to a further refrigeratin action to condense any remaining napht alene vapors formlng a fog of minute liquid particles which Wlll be precipitated against the collecting electrodes, due to the action of the force of the ionization zones. tated against'the first sections of the collect- These condensed and precipitated liquid particles will escape or flow through the traps 17 '3 onto the conical partition 19 and be drained through the outlets or drains 19.

After the point has been reached where the naphthalene has been condensed and removed the gases are comparatively clean and they then pass out from the space between the electrodes 16 and 17 into the chamber 22 and escape throu h the outlet 23. Any particles which may e precipitated by the ionization action of the electrodes below the traps 17 a will be collected into the bottom of the chamber 22 and removed through the discharge openings 24 which are normally closed by bells 25.

If it is desired or found beneficial, suitable s ray nozzles may be located in the path of ow of the gases at a point above the lower spider members 15 and a liquefied naphthalene product sprayed into the gases to form a nucleus to aid in the gathering of the finer naphthalene particles contained in the gaseous fluids being cleaned.

Experience has shown that, by proper adjustment with regardto the length, of the difierent collecting electrode sections and the amount of refrigeration applied, commercially pure pitch and tar, anthracene, and naphthalene may be separately obtained at ,the various stages of the apparatus above described.

While I have described my apparatus as being particularly adapted to the cleaning and separation of by-products from producer and coke oven gases, it will be, of course, understood, that I do not wish to be limited to this specific application of the apparatus since it may be advantageously used to clean other gases or fluids and to se arate other ingredients than the ones name I claim:

1. Apparatus for removing and separating vaporized products from gaseous fluids comprising a casing, opposing electrode systems within said casing, having a discharge electrode and a tubular collectlng electrode, said electrode s stems being adapted to form ionization eldstherebetween for precipitatin the vaporized products, a plurality o spaced traps formed along the length of each of said collecting electrodes and refrigerating jackets surrounding said collecting electrodes to lower the temperature of the gases and cause condensation of the vaporized products.

2. Apparatus for removing and separating vaporized products from gaseous fluids comprising a casing, opposing electrode systems within said casing, having a discharge electrode and a tubular collectlng electrode.

said electrode systems forming a plurality of ionization fields therebetween for precipitatin the vaporized products, a plurality o spaced traps formed along the length of each of said collecting electrode and refrigerating jackets surrounding said "electrodes, and means located below each of said series of traps for collectin and dispensing the precipitated pro ucts discharged through said traps. w

3. An apparatus of the 'class described comprising a casing having inlet and outlet ports, a supportin structure within said casing, opposing e ectrode systems within said casin having discharge electrodes and tubular co lecting electrodes, said dischar e electrodes being progressively reduced in i' refrigerating jackets ameter toward their lower ends and being supported and mounted in said su porting structure, said tubular collecting electrodes being composed of a plurality of sections, each of said sections being of less diameter than their immediate preceding sections, and telescopically extending within the preceding section an appreciable distance, said telescopic portions of said collecting electrodes, forming traps through which the collected products are adapted to flow, refrigerating jackets surrounding said electrodes and conical transversely extending walls arranged below each of said series of traps adapted to collect and retain the products discharged therethrough.

4. An apparatus of the class described, comprising a casing, having inlet and outlet ports, a supporting structure within said casing, opposing electrode systems within said'casing. having discharge electrodes and tubular collecting electrodes, said discharge electrodes being progressively reduced in diameter, toward their lower end, and being supported and mounted in said su porting structure, said tubular collectin e ectrodes being likewise progressively re need in diameter to correspond with the reduction in diameter of the discharge electrode, a plurality of spaced traps formed along the length of each of said collecting. electrodes diameter toward their lower ends and being supported and mounted in said su porting structure, said tubular collecting e ectrodes being composed of a plurality of sections, each of said sections being of less diameter than their immediate preceding sections and telescopically extending within the precedin sections an -appreciable distance, said te escopic portions of said collecting .electrodes forming outlet traps through which' the collected products are adaptedto flow,

I concentrically arranged aroundeach of said collecting electrodes, and means arranged below each of said series of traps adapted to collect and retain the products discharged there-v throufi.

6. apparatus of the class described, comprising a casing, having inlet and outlet ports, a Supporting structure within said casing, opposing electrode systems within said casing, having discharge electrodes and tubular collecting electrodes, said discharge electrodes being progressively reduced in diameter. toward their lower end, and be ing supported and mounted in said supporting structure, said tubular collecting electrodes being likewise progressively reduced in diameter to correspond with the reduction of the discharge electrode,-a plurality of spaced traps formed along the length of each of said collecting electrodes through which the collected produ'cts precipitated against the collecting electrodes are adapted to escape, refrigerating jackets surrounding said collecting electrodes,.centrifugal head members-mounted in said collecting electrodes, having a plurality of helical passages around their outer periphery through which the gases travel, and conical transversely extending walls arranged below each of said series of traps adapted to collect and retain the products which escape throu h said traps.

7. he method of separating vapor particles from a stream of gaseous fluids, comprising, first, imparting a mechanicalcentrifugal whirling motion thereto, then successively refrigerating said stream to condense liquid vapors held therein, forming a fog of liquid particles, subjecting said refrigerated stream to successive -1onization zones to precipitate the liquid particles forming said fog, and collecting said precipitate'd liquid particles.

8. The method of separating vapor particles from a stream of gaseous fluids, comprising first, initially ionizing said stream and lmparting a mechanical centrifugal whirling motion thereto, then successively refrigerating said stream to condense liquid vapors held therein. forming a fog of liquid particles, subjecting said refrigerated stream to successive ionization zones to precipitate the liquid particles forming fog, and collecting said precipitated liquid particles.

In testimony whereof I have hereunto signed my name.

ARTHUR F. NESBIT.

said

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