US2592508A - Electrical precipitator - Google Patents

Description

April 8, 1952 J, PHYL 2,592,508

ELECTRICAL PRECIPITATOR Filed. Feb. 10, 1950 3 Sheets-Sheet l Z a- P INVENTOR t sskHP/wg BY M ATTORNEYS April 8, 1952 J. PHYL 2,592,508

ELECTRICAL PRECIPITATOR Filed Feb. 10, 1950 5 Sheets-Sheet 2 v INVENTOR rJbSEPHP/WL,

BY, M W

ATTORNEYS April 8; 1952 J, PHYL 2,592,508

ELECTRICAL PRECIPITATOR Filed Feb. 10, 1950 5 Sheets-Sheet 5 INVENTOR v ATTORNEYS Patented Apr. 8, 1952 ELECTRICAL PRECIPITATOR Joseph 'Phyl, Fanwood, N. J assignor to Research Corporation, New. York, N. Y a corporation of New York Application February 10, 1950, Serial No. 143,509

'7 Glaims. 1

This invention relates to electrical precipita-' tion apparatus for the separation of suspended materials from gases.

More particularly the invention relates to collecting electrodes for use in electrical precipitation apparatus in which the suspended material is precipitated in liquid, or semi-solid form, for example, in the collection of tar particles and sulfuric acid mist, and in the wet type of electrical precipitators in which solid particles are collected in the form of a sludge or are flushed from the collecting electrodes by a liquid. A hopper or collecting pan is generally provided at the bottom of the precipitator to collect the precipi tated liquid, semi-solid or sludge as it drips off the lower edges of the collecting electrodes.

For maximum efiiciency electrical precipitators should be operated with the electrical potential between the discharge and collecting electrodes just below the arcing point. It has been found however that the maximum potential between the discharge and collecting electrodes. must be materially lowered to prevent arcing and corona discharge of reverse polarity from the places where the collected material drips from the collecting electrodes in the above mentioned types of precipitators.

A principal object of the invention is to provide collecting electrodes having means for directing the flow of the liquid, semi-solids or sludge, at the bottom of the electrodes to substantially reduce the possibility of back corona discharge and arcing at the drip point, thus permitting the electrical precipitation apparatus to be operated at a higher potential thanheretofore possible and thereby substantially increasing the efhciency of the apparatus.

For the purpose of illustration the invention will be more particularly described as applied to an electrical precipitator for cleaning hot tarcontaining gases, with reference to the accompanying drawings in which:

Fig. 1 is a vertical section of a vertical flow precipitator employing square pipe collecting electrodes constructed in accordance with the principles of the invention;

Fig. 2 is a sectional view of line 2-2 of the precipitator shown in Fig. 1 of the drawings;

Fig. 3 is an enlarged fragmentary view of a square pipe electrode having modified drip points;

Fig. 4 is an enlarged fragmentary view of a hexagonal pipe collecting electrode constructed in accordance with the principles of the invention;

. Fig. 5 is a diagrammatic vertical section of a horizontal flow precipitator employing plate type collecting electrodes embodying the principles of the invention; and

Fig. 6 is a fragmentary section on line 6-6 of Fig. 5.

Referring to the drawings and in particular to Figs. 1, 2 and 3, H1 is the shell or casing oi the precipitator having a gas inlet H and outlet l2 Within the casing discharge electrodes 13 are shown suspended from a support l4, and passing vertically through the centers of square pipe collecting electrodes l5. A retaining frame I6 is shown at the lower ends of electrodes I3 to so,-v cure them from lateral displacement and from swinging from side to side in the as stream, The precipitated tar is collected in the bottom of the precipitator and is withdrawn through drain IT.

The lower edges of the collecting electrodes are provided with serratures, as more clearly shown in Fig. 3 of the drawings. Points IQ of the serrated electrodes are at the corners of the square pipes and thus provide drip points at the, furthest points from the centrally located discharge electrodes I3.

In operation hot tar-laden gases, enter the precipitator through gas inlet II, and flow upwardly through the square pipe collecting electrodes, wherein the tar particles become ionized and are precipitated upon the inner surfaces of the col.- lecting electrodes. The precipitated tar flows down the electrodes and is directed by the serrated edges 18 to the drippoints ill at the corners of the square pipes. With the drip points located at the corners of the collecting electrodes, the points furthest from the discharge electrodes, the possibility of arcing at the drip Points is sub stantially reduced.

The drip points shown on the electrode illustrated in Fig. 3 of the drawings are provided with smoothly rounded projections 20 having spherically shaped bases, to further reduce the tendency toward back-corona and are overs at the drip points by eliminating the sharp points of the serrated electrodes.

In Fig. 4 of the drawings a hexagonal collecting electrode 2| is shown constructed with a serrated lower end. The drip points l9 are positioned at the corners of the polygonal tubes electrode at the points of greatest distance from the centrally located discharge electrode l3.

With reference to Figs. 5 and 6 of the drawing it will be seen that the principles of the invention are equally adaptable for use on precipitators employing plate type electrodes, and on precipitators operating with a horizontal gas flow. In the illustrative embodiments shown in Figs. 5 and 6, I is the shell of a horizontal gas flow precipitator having a gas inlet and outlet II and I 2' respectively. Within the precipitator are discharge electrodes i3 suspended between the plate type collecting electrodes I5, the lower edges of which are serrated in accordance with the principles of the invention to provide drip points l9 located at a greater distance from the discharge electrodes l3 than the perpendicular distance between the discharge and collecting electrodes.

From the foregoing description it will be seen that the present invention provides a method of constructing collecting electrodes for use in electrical precipitation apparatus in which the suspended material is precipitated in liquid, or semisolid form and in the wet type of electrical precipitators in which solid particles are collected in the form of a sludge or are flushed from the collecting electrodes by a liquid, whereby the aims, objects and advantages of the invention are fully accomplished.

It will be evident that various modifications may be made in the construction of the device and in the form and number of drip points. For example, the lower ends of the collecting electrodes may be scalloped instead of serrated to lessen the possibility of arc over at the drip points.

I claim:

1. In an electrical precipitator for separating suspended materials from gases comprising spaced substantially vertical discharge electrodes, and parallel collecting electrodes adjacent said discharge electrodes, means at the lower ends of the collecting electrodes directing the flow of precipitated liquids, semi-solids and sludge to drip points remote from the discharge electrodes, whereby discharges at the drip points are substantially reduced.

2. In an electrical precipitator for separating suspended materials from gases comprising spaced substantially vertical discharge electrodes, and. parallel collecting electrodes, as defined in claim 1, wherein the means directing the flow of precipitated liquids, semi-solids, and sludge to drip points, comprise serratures at the lower ends of the collecting electrodes.

3. In an electrical precipitator .for separating suspended materials from gases comprising substantially vertical polygonal tube collecting electrodes and substantially vertical discharge electrodes within said tubular collecting electrodes, serratures at the lower ends of the collecting elec-- trodes directing the flow of precipitated liquids, semi-solids and sludge to drip points at the lower corners of the collecting electrodes, whereby dis- 4 charges at the drip points are substantially reduced.

4. In an electrical precipitator for separating suspended materials from gases as defined in claim 3, smoothly rounded members projecting downwardly from the drip points of the collecting electrodes.

5. In an electrical precipitator for separating suspended materials from gases comprising substantially vertical square tube collecting electrodes and substantially vertical discharge electrodes within said tubular collecting electrodes, serratures at the lower ends of the collecting electrodes directing the flow of precipitated liquids, semi-solids, and sludge to drip points at the lower corners of the collecting electrodes, whereby discharges at the drip points are substantially reduced.

6. In an electrical precipitator for separating suspended materials from gases comprising spaced substantially vertical discharge electrodes and parallel plate collecting electrodes adjacent said discharge electrodes, serratures along the lower edges of said plate electrodes directing the flow of precipitated liquids, semi-solids,- and sludge to drip points remote from the discharge electrodes, whereby discharges at the drip points are substantially reduced.

7. In an electrical precipitator for separatin suspended materials from gases comprising spaced substantially vertical discharge electrodes and parallel plate collecting electrodes adjacent said discharge electrodes, means directing the flow of precipitated liquids, semi-solids and sludge t0 drip points positioned along the lower edges of the plate collecting electrodes between the spaced discharge electrodes to substantially reduce discharges at the drip points, said directing means comprising serratures along the lower edges of said plate electrodes. I

JOSEPH PHYL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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