US1579462A - Method of and apparatus for separating light materials from gases - Google Patents

Description

April 6 1926. 1,579,462

H. A. WINTERMUTE METHOD OF AND AIfPARATUS FOR SEPARATING LIGHT MATERIALS FROM GASES Filed Feb. 11,- 1925 Patented Apr. 6, 1926.

' UNITED STATES PATENT. OFFICE.

man: A. manners, or nnw Yonr,

N. Y., ASSIGNOR TO RESEARCH CORPORA- nor," on NEW Yonx, N. Y. A conronnrron' on NEW YORK.

IITHOD OF AND APPAB ATUS FOR SEPARATING LIGHT MATERIALS FRbM GASES.

Application filed February 7 To all whom it may concern:

Be it known that I, HARRY A. WINTER- m, a citizen of the United States, residing at New York, in the county of New 6 York and State of New York, have invented certain new and useful Improvements in Methods of and Apparatus for Separating Lilght Materials from Gases, of which the f owing is a specification.

This invention relates to the separation of suspended material from gases and more in particular to electric separation of light ufiy material such as oarbon black.

For a full understanding of the invention reference is made to the accompanying drawing which is a more or less diagrammatic representation of what I' consider a preferred embodiment of the invention.

In the. drawing 10 represents a tubular collecting electrode and 11 a wire discharge electrode commonly used in the art of electric precipitation. It is understood that this form of precipitator' is merely representative of electric recipit-ators in general and has no particu ar or special si 'ficance.

Any other precipitator in which t e collecting electrode surfaces define gas passages may find application.

The lower end of the electrodes 10 and 11 terminates in a lower header 12 and adjacent the header 12 is a compartment 13 for housing the insulator 14 on which is supported a rod 15 or the like for kee ing the dischar e electrode 11 centered, .t e usual ball 16 olding the wire electrode 11 taut.

The gas stream carrying the material in suspenslon enters through the inlet 17.

Above the header 12 is disposed a settling chamber 18 which is in communication with the interior of the collecting electrode 10 through a perforated portion 19 thereof. The collectin electrode 10 terminates above the settling c amber.

. The gas stream entering through 1nlet 45 17 passes up through the tubular collecting electrode 10 and the suspended particles under the action of the discharge electrode are precipitated a ainst the collecting surface.v

I have foun that when the velocity of. the

11, 1925. Serial No. 8,491.

1s dislodged from the electrode surface in the form of large agglomerated masses and carried along the walls of the collecting electrode and may then be separated from the gas stream.

I have also discovered that these agglomerated masses moving with the gas ump back and forth between thedischarge electrode and the collecting electrode much the same as a pith ball jumps back and forth between two oppositely charged plates. When they reach an open space in the collecting electrode, they jump back and forth until the momentum carries them out of the field of influence. They then drop due to gravity action and may be collected.

I have also found it unnecessary to use any of the other methods commonly employed in electrical precipitation, such as rapping, scraping or brushing, for dislodging the material precipitated on the electrodes. This self-cleaning feature is very desirable and advantageous in all precipitation work and especially so in the precipitation of lamp black.

This discovery I may practically utilizein several ways. In actual ractice I have used a rod wound spira ly with the convolutions about 1" a art to form the perforated section 19. Sther constructions may be found suitable for the purpose. While a plain opening is satisfactory to a certain extent, I have ound that provisions for maintaining an electric field through the opening are much more effective and are a practical desideratum. The electric field may be-pr0- duced by an ,metallic frame or screenwork connected w1th the collecting electrode and providing openings large enough for 'the ag lomerated masses to freely pass through.

ilthough there is considerable latitude in regard to the velocity of the as stream in its relation to the potential ifi'erence and gap between the electrodes and the length of the electrodes and the condition of the sea, I have found in practical tests with tu ular collecting electrodes of about 12" diameter" and 18 feet long, that a' gas velocity of 7-9 ft. sec. gives very good results. The dislodgement of agglomerated particles and their motion became apparent about four minutes after starting operations and continued unint'erruptedly so long as the gas flow was maintained. a

When the agglomerated particles reach the perforated section, the to and fro motion under the action of the electric field eventually carries them into the perforations beyond a critical point where the action of the field cannot pull them back and they drop there while the gas itself passes out of the terminal end of the passage defined by the tube or other collecting electrodes.

In the settling chamber the particles are out of the sphere of the kinetic action of the gas stream and can settle and may then be removed.

The principle of operation is not related to what is sometimes called electric wind. In fact, I found that the operation may be carried out with relatively low voltages and that the discharge electrode may advantageously be charged positively rather than negatively as is the general practice for obtaining the highest potential gradient.

The operation depends essentially upon the application of an electric field suflicient to precipitate the fine particles upon the collecting electrode, and upon the rate of gas flow. These forces must be so controlled that the agglomerated material is dislodged and caused to move with a to and fro motion between the collecting and discharge electrodes and in a resultant direction substantially parallel with the gas flow to an opening through which it is removed.

As soon as the opening is reached, the support afforded by the collecting electrode surface up to the opening is no longer prescnt so that the resultant movement of the agglomerated masses due to the kinetic action of the gas stream and the electric action is disturbed and the said masses drop out of the gas stream in the only direction in which theycan drop, i. e. through the opening into the space where there is neither electric action nor akinetic action of gas.

While the movement of the detached agglomerated masses out of the gas stream may be promoted by a slight negative pressure in the settling chamber relative to that in the passage way defined, I have found that such negative pressure is not necessary for successful operation.

While the mode of operation applies especially to the separation of carbon black or the like, it necessarily applies to all light flufly materials having the physical characteristics of electrically precipitated carbon black.

I claim: 1

1. The method of separating light sus-.

pended material from gases, which consists in passing a gas stream carrying the material in suspension through a passage, and subjecting the gas stream to an electric field causing a deposit of the material on the walls of the passage, the gas being passed through the passage at such velocity that under the action of the gas stream masses of the deposit are detached in agglomerated -form and carried onwardly by the stream.

2. Method according to claim 1 including the step of collecting the agglomerated masses after detaclu'nent from the walls of the passage.

The method of separating light sus pended material from gases, which consists in passing a gas stream carrying the material in suspension through an electric precipitator defining a passageway for said gas stream, under such conditions of velocity asto cause the particles deposited and ag;

glomerated under the electric action to be dislodged from the collecting surface and to move parallel to the gas stream and then allowing the dislodged particles to move out of the gas stream under the action of an electric field.

4. The method of separating light suspended material from gases, which consists in passing a gas stream carrying the mate rial in suspension through an electric pre cipitator defining a passageway, subjecting the gas stream to such electric action as to cause collection and agglomeration of the suspended material on the walls of the passage, controlling the rate of flow of the gas stream so as to cause the gases to dislodge the collected and agglomerated material and carry the same substantially parallel to the gas stream, and allowing the dislodged material to move out of the gas stream under the action of the electricfield.

5. The method of separating light suspended material from gases, which consists in passing a gas stream carrying the material in suspension through an electric precipitator defining a passageway, subjecting the gas stream to such electric action as to cause collection and agglomeration of the suspended material on the walls of the passage, controlling the rate of flow of the gas stream so as to cause the gases to dislodge the collected and agglomerated material, and maintain continuously substantially clean electrodes.

6. Apparatus for separating light suspended material from gas, comprising a ver tical tubular collecting electrode having an uninterrupted collecting surface from the bottom to near the top and a perforated portion near the top, defining relatively large openings and a discharge electrode extending through the collecting electrode.

. Apparatus for separating light suspended material from gas, comprising a vertical gas passage imperforate fromthe bottom-to near the to v and constituted at least in part by collecting electrode means, the 5 passage having near its top an openi and a screen in said opening, and a disc arge electrode extending through the gas passage.

8. Apparatus according to claim 7, including a settling chamber surrounding the said gas passage and in communication there- 10 with through said screen:

In test' ony whereof, I aflix my signature.

HARRY A. WINTERMUTE.

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