US1119469A - Means for removing particles of suspended matter from bodies of gas or fluid. - Google Patents

Description

W. W. STRONG & A. F. NESBIT. MEANS FOR REMOVING PARTICLES OF SUSPENDED MATTER FROM BODIES 0F GAS 0R FLUID.

APPLICATION FILED FEB.11,1913.

Patented Dec. 1, 1914.

Z Qp/ n STATE PATENT oFFIcE.

' WILLIAM WALKER STRONG, F PITTSBURGH, AND ARTHUR F. NESBIT, 0F

KINSIBURG, PENNSYLVANIE ASSIGNORS TO R. B. MELLON, 0F PITTSBURGH,

PENNSYLVANIA. I p

MEANS FOR- nEMovINo PARTICLES or sUsrnNnEn MATTER mom Bonnie or GAS on 4 FLUID. r

Specification or Letters Patent. P t nt 1914 Application filed Tebruerf To all whom it may concern:

11,- 1913. Seria 1N0. 747,753

designated as a stream of ions, orfian electric I 1 pendedMatter from Bo we of Gas or Fluid,

The object of the present invention is to lltlllZG these phenomena in removing sire-""56 pended matter from fluids, by assing. the fiulds containing the matter toge removed." between an'active and agrounded electrode,

the latter'being shaped to secure the peculiar advantages. desired. -60

and ARTHUR F. Nnsnrr, citizens of.-the United States, residing at Pittsburgh and Wilkinsburg, respectively, in the county of Allegheny and State of Pennsylvania," have invented new and useful Improvements in the Means for Removin Particles of S115;

of which the-following is a specification."

This invention relates to improved means, for removing articles of suspended matter from bodies 0 gas or fluids, by the application of electrical discharges to the said bodies. a v V Heretofore electrical dischargeshave been employed for the purpose of removing suspended matter from fluids, etc.-,.which discharges may consist 'of brush discharges, the electrical wind, the corona discharge, etc. The nature of these discharges is not well known, but they. involve among other phenomena, secondary ionization of the fluid medium, which may be dueto the collision of the ions with the fluid particles, or it may be due to electromagnetic pulses or waves. It is known, however, that electrical discharges of this kind result in a copious pro duction of ions. Any discharge can be ef-' fected only by the use of one or'more elec trodes placed in or near the fluid medium, and the electrical discharge'may be caused to takeplace from one electrode which is designated as the active electrode. In the art of'removing matter from fluids the electric field may be made very concentrated near the active electrode in order that the luminous,heat and ionization effects may be localized in the neighborhood of the said electrode. The secondar ionization produced in this region resu' ts in the production of a large number of positive and negative ions. The ions having charges dissimilar to that of the active electrode are attracted-toward it and are'said togive-nm their charge to this electrode as ions of the said sign of charge. Ions possessin a si of charge that is the same as that o the ac" tive electrode'are repelled from it and if the necessary ionization is sufiiciently intense and continuous, this flow of ions will be The shape of the grounded electrode ma varyaccordin'g to the character of thewor to be done de endin upon the conditions under which t e'flui I p'ended matter areftobe treated. The dif-' ferent conditions are well/illustrated in the problems encountered in theprecipitation;

of smokeproduced in round'houses', railroad tunnels, .and 1n general wherever incomplete combustion takes place; the precipitation of fumesand dust from blast furnaces of various types, etc. The velocity of the fluid orfiuids to be treated, the space: available for the precipitation chambers,' and the posdiffer widely, de pending upon the particular; problem under consideration, and the results to be effected.

,sible methods of cleaning The invention will be hereinafter fully set forth and particularly pointed out in the claims. f In the accompanying drawin :Figure.1 1s a perspective view, partial y diagram- ,matic, illustrating our invention. The electric circuits in the high potential side of the transformer may'conslst of resistances, inductances, and capacities distributed in series or parallel groupings in any form most convenient for the results to be effected.

. The resistances may be partly or wholly in the form of s ark gaps. Fig. 2 is a horizontal s'eotiona view. Fig. 3 is a similar view of a slightly modified form. Figs. 4, 5 and 6 are diagrammatic views illustrating the action of the electrodes.

Referring to the drawing, 10 designates a generator of any suitable or preferred ty e, and 11 is the primary low potential coil 0 a transformer 12. Thehigh potential coil 14 of the transformer is connected with a suitable rectifying device 15, the same being utilized for maintaining the potential of the active electrode 16, unipolar. Itwill be un}.

s containing the suse by the portions derstood, however, that we do not desire to limit ourselves to the use of a unidirectional current, or to the use of a rectifier, although I prefer to employ the same.

In Figs. 1 and 2 the grounded electrode is illustrated as cemprislng a series of approximately semicircular concavo-convex portions 17 united by converging fiat portions 18, there being two oppositely disposed grounded. electrodes forming between them a passage way'of" irregular or wave-like form. An entrance conduit or guide is formed by. two parallel plates 19. 7 It will be noted that there is one active electrode 16 for each of the approximately circular cells formed 17, said electrodes 16 being centrally disposed in said cells and extending longitudinally therethrough.

In Fig. 3 we have shown a slight modification whichconsists in connecting the concavoconvex portions 20 forming the circular cells by contractedwalls21 which are curved inwardly instead of being straight as in Fig. 2.

During the operation of the apparatus the bodies containing the suspended matter enter between the plates 19, in the direction of the arrow. and pass successively "through the circular, cells and contracted portions. .until discharged. In their passage through the space between the grounded electrodes the suspended particles may adhere to the said grounded electrodes or be precipitated into a deposition chamber, the bodies containin --said matters passing progressively into. t e influence of he successive active electrodes. "lltis obvious that if desired, fluid bodies could be made to'travel in a direction parallel with the active electrodes 16.

In practice, irrespective of what the directionof travel may be, the fluids, subjected to the action of the ionic currents are wholly or partly cleaned of their solid and liquid matters held in suspension, the latter being deposited upon the inside surface of the grounded electrodes or precipitated into the deposition chamber. When suflicient matter has been deposited upon the surface of one or both electrodes to provide for a gap for a, disruptive discharge to pass, sparking takes place, and this causes more or less of the deposited matter upon or adhering to the electrodes to be loosened from the same. The portions of the deposited matter thus loosened may fall downthrough the cell and be collected in the deposition chamber. In

this 'method of cleaning the electrodes it is tr de 16 i necessary to havecertain predetermined re-v -;lations between the capacity, self induction,

and resistance factors of the high tension circuit so-thatthe discharge is disruptive when the distance between the electrode 16 and the deposited matter is less than the disru'ptive potential of the gases.- For the puret he pose of producing disruptive or oscillatory discharges various suitable conditions may be imposed upon the electrical circuits connected to the active and grounded system of electrodes. For the purpose of illustration beside the resistance, capacity and self-induction of the transformer itself, we have shown in Fig. 1 certain combinations of resistances 22, 23, capacities, 24 and 25, selfinductances, 26 and 27, and spark gaps 28 and 29, distributed in the secondary circuit, so that under Working conditions electromagnetic oscillations "of the proper fre-' quency and damping factor are produced. These resistances, capacities, self-inductances and spark gaps are placed in whatever parts of the .circuit found most suitable or de sirable for the results desired,'a'nd for obvious reasons we do not limit ourselves to" the precise arrangement illustrated. Among other conditions may be included the use of a number of phases of current or electroinotive force; the frequency of these phases may have any suitable value and need not bel ef the same value. Thus one phase may" have the values of its capacity, self inductance and resistance such that a discharge due to this phase would. be disruptive or oscillatory in nature, while the discharges ofthe other phases could be of a flamator or arc-like character. The impression of these electromotive forces and current waves need notjoe simultaneous and may be efiected "by independent electrical circuits. In a like, manner the phase relation between the current and electromotive force waves of any circuit may be regulated so as to produce disruptive or oscillatory discharges, and by this means effect the removal of matter contained in the'fluids subjected to the action of the electrodes. It is obvious, however, that the deposited matter may be removed from the electrodes by causing the latter to vibrate, for instance, by striking them with a hammer, or the like.

llt has been found experimentally that when precipitating the so-called smoke from softv coal furnaces, there is considerable ash and tar carried along with the soot (or carbon) and on account of the high temperature of these ingredients, more or less adheres to the central or active electrode and also to the irmerv walls of the grounded electrode. The actualconditions which have been met may be illustrated by reference to Figs, 4, 5, and 6. In F ig. 4 the active elecfor the sake of illustration may be. taken as about 3 of an inch in radial depth at the position a and at the positions I) and 0, somewhat less. ,As soon as the distance at the point a between the electrode 17 and the deposited matter has been reduced by accumulations upon the electrode 16, to such a value shown as having a deposit, which 12o lod ed the deposit the deposit may vary 3.5 through it decreases,

duce electrical oscillation.

i thataa disruptive discharge takes place, a -momentary spark passes, and simultaneously with the occurrence of posit on the actual ielectrode between the 5 planes or y and u 'v is violently dislod ed and settles into the chamber below. (Sic Fig. 5.) At the same time a large patch ofthe com aratively thin deposit on the inner wall of tl ie grounded electrode would become de- 10 tached from the latter andbreaking into small pieces also fall into. the deposition chamber. The next disruptive discharge wouldin vall robability take place in suc- A -cession at sue positions as b and 0 respectively. It has been our experience that such once in an hour,

of the corona elsewhere along the electrode 16.

The peculiar pro electric are, that t e potential difference across its terminals increases as the current may be utilized to pro- The grounded electrode 17 is shown to be the collecting electrode, in the drawing, the object of making'it such being to minimize 40 the amount of insulationynecessary for the bulky par tslof the electrodes and at the same time properly control the flow of gases, etc., which may be admitted' The electrode 16 is called the active electrode because the electric field and consequent ionization is -most intense at the surface of this electrode' a By converging the approaches to the'bulg- 'ing portions of the grounded electrode the flow of the gaseous or fluid bodies is directed against the active electrode, thereby bringing said bodies into themost intense part of the electric field, resulting in a more effective precipitation of-the suspended matter, and also utilizing the sweeping action of. the gaseous or other. bodies in keeping the active electrodes clean of deposited material. This sweeping action of the bodies scours the walls of.the grounded v electrode tending also to clean said walls of deposited material? Having thus explained. the nature of pur *iiive'ntion, and described an operative manne" of eonstructing and usingthe same, gh without attempting toset forth all this spark the dethe same time causes no apparent diminution erty possessed by ana grounded electrode provided with spac d 1 apart bulging portions connected by intermediate straight walls, and means for maintaining said electrodes at a high difl'erence of potential.

'3. An improvement in' means for removving suspended matter from bodies of fluids and the like comprising a grounded electrode formed of .-oppositely disposed members having bulging portions forming cells,

.an active electrode in each cell, and means for maintaining said active and grounded electrodes at a high difference of potential.

ing suspended matter from bodies of fluid and the like comprising a grounded electrode formed of oppositely disposed members provided with spaced apart bulging portions foriningapproximately cylindrical ,cells, active. electrodes centrally disposcd in -said cells, and means for maintaining said electrodes at-a high difference of potential.

5. An improvement in means for removing suspended matter from bodies of fluid and thevlike comprising a grounded electrode formed of oppositely disposed members having bulging portions forming cells and walls connecting said bulging portions to form constricted passages, active electrodes in said cells, and means for maintaining said electrodes at a high difference of potentlal.

6. An im rovement in means for removing suspen ed matter from bodies of fluid and the like comprising a grounded electrode formed of oppositely disposed members having bulging portions forming cells, said bulging portions being connected by 1ntermediate converging straight walls to form constricted passages, active electrodes in saidpassages, and means for maintaining said "electrodes at a high difference of potential.

7. An im rovement in means for removing suspen ed matter. from bodies of fluid and thelike comprising a grounded electrode provided with a: plurality of spaced apart cells connected by constr cted assage ways, active electrodes in said cel s, and means for maintaining said electrodes at a high difference of potential.

, 4. 'An improvement in means for roniow' an, umeeo 8. An improvement in means for removmg suspended matter from bodies of fluid and the like, comprising a grounded elec-.

trode provided with a passage through which said bodies are caused to travel and having a tapered outlet, an active electrode within said grounded electrode, and means for maintaining said electrodes at'a high difference of potential.

In testimony whereof We have hereunto set 10 VVILIJIAM WALKER STRONG. ARTHUR F. NriSBI'I.

' "Witnesses 'IHoMAs (JAIN, W. J. MOORE.

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