US1773963A - Apparatus for electrical precipitation - Google Patents

Description

Aug. 26, 1930. w. DEUTSCH A-PRARATUS FOR ELECTRICAL PRECIPITATION Filed July 25, 1928 2 mu m. m w I f m Patented UNITED STATES PATENT". OFFICE WALTHER DEUTSCH, OI F BANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOB TO INTER- NATIONAL PRECIPITATION COMPANY, 01'! LOS ANGELES, CALIFORNIA, A CORPORA- 'IION OF CALIFORNIA APPARATUS ron' nnnc'rnrcan rmzorrrra'r'ron Application filed m 25, 1928, Serial no.

This invention relates to apparatus for the electrical precipitation of suspended particles from gases. The principal object of the invention is to provide for automatic shutting off of the gas flow through an electrical precipitator upon failure or interruption of the current supplied to the electrodes thereof, so-

i that the possibility of unclean gas passing from the precipitator into the atmosphere or" into subsequent apparatus of any sort, and a particular object of the invention is to prevent this contingency from arising. An example of such a case is in the removal of' arsenic from the gases before entering the contact chamber in the contact process of sulphurlc acid manufacture, since if the gases were'permitted to enter such contact chamher while still containing appreciable quantities of arsenic, the catalytic substance in thechamber would, as is well known, beeffected in a deleterious manner.

With this object .in view the apparatus of my invention comprises essentially an electrical precipitator, an electric circuit for supplying current thereto, means for passing gas therethrough, dampermeans for cutting off the flow of such gas, and means operable upon cessation or undue decrease of current fiow 1n said circuit to close said damper. The means for efie'cting automatic closing of the damper.

may comprisefor example a relay coil or electromagnet connected in the energizing circuito-f the precipitator, and means operable when the current flow therethrough fallsbelow a certain amount to operate through suitable mechanism to cause closing of the damper. The damper may be located either in the inlet or outlet flue of the electrical precipitator.

The accompanying drawings illustrate an embodiment of my invention and referring thereto. Fig. l'is-a partly diagrammaticside ele- 4 s vation of an electrical precipitator showing;

my invention applied thereto.

' Fig. 2 is an' enlarged rear view of part of the damper closing mechanism shown in Fig.1.,"

The electrical precipitator shownin the drawing comprises bottom header 1, top head- 295,340, and in Germany August 20,1887.

er 2 and a plurality of pipes or tubes 3 ex I tending-between said headers and constitutmg the collecting electrode. Gas conducting flues 4 and 5 are shown as connected to the lower and upper headers, one of said flues serving as an inlet flue and the other as an outlet flue for the gases to be treated. Discharge electrode membersfi consisting for example of wires or small rods are suspended Within the respective pipes 3, as by means of a suitable supporting framework 7 mountalternating current at commercial voltage,

and a rectifyingdevice such as a mechanical rectifier consisting of a rotating disc 14 of insulating material and provided in well known manner with two contact segments 15 and16adapted to contact with or to pass in current transmitting relation with-four contact members indicated at 17 "to 20. Two diametrically opposite contact members such as 17 and 19 are connected to the secondary winding of transformer 12, said secondary winding being adapted to give the necessary high voltage for operation of the precipita tor, for example 30,000 to 75,000 volts or more. One of the intermediate contacts such as 18 is connected by wire 23 to some part of the discharge electrode system, for example to a part of the supporting frame 7 I as shown, while the other contact 20 is connected by wire 24 to the collecting electrode 4 system,-said wire being preferably grounded as indicated at 25 so as to ground the col-- lecting electrodes and also the contact 20 'of the rectifier. Included in the wire 24 is a .relay coil or .electromagnet 26, which is adapted as hereinafter described a to cause closing of the damper when the current flow therethrough ceases or falls below a certain value.

The electrical precipitator and energizing circuit therefor above described are already well known and the details thereof form n0 essential part of the invention. The invention is equally applicable to any other form of electrical precipitating apparatus, and other forms of energizing circuit may also be used.

A damper may be provided in either, of the flues 4 or 5. Two arms 31 and 32 are shown as connected to the shaft of said damper, the end of arm 31 being connected to a cable 33 passing over winding drum 34' which is provided with a crank orhandle 35 whereby the damper may be manually moved to open position as shown. The winding drum 34 is provided with a ratchet member 36 and a pawl or catch member 37 is pivoted at 38 and is normally held by spring 39 in engagement with the teeth of said ratchet;

member. Upon the end of arm 32 is hung a suitable weight member 41 which may be. provided with a projecting arm 42. said weight member being operable to move the damper to closed position 11 on movement of pawl member 37 out of e gagement with ratchet 36.

Suitable means are provided for causing such release of pawLmember 37 upon deenergization of electromagnet 26. 7 Such means may comprise an electromagnet 44 adapted to attract an armature 45 on said pawl'member, and a switch controlled by electromagnet 26 and comprising for example a fixed contact member 45 and a contact member 46 on arm 47, which is pivotally mounted at 48 and is provided with an arma-- ture 49 acted upon by electromagnet 46, whereby contact 46 is normally held out of engagement with contact 45, a spring 51 being' provided for closing said contacts when the current flow 1n electromagnet 26 ceases or falls below a certain value, for example below the current value corresponding to the a proper operating voltage or potential between the electrodes of the precipitator. A suitable source of current, such as battery 53 is connected to the relay switch comprising I contact members 45 and 46 and to electro- 'magnet 44 in series. Another pair of contact members 56 and 57 are preferably included in the circuit, said contact members being normally held in closed position by means of leaf spring 58, but; one of said members being mounted upon arm 59 adapted to be engaged by arm 42 on weight member 41 when sa1d we1ght member ispermitted to'fall as hereinafter described.

- The. operation-of the above described'apparatus is as follows. So long as the supply of electric current to the precipitator is malnta'lned, or so long as the current flow therethrough remains above a certain value,

electromagnet 26 will beenergized sufficient- 1y to hold contact member 46 out of engagement with contact 45 against the action of -s ring 51, and magnet 44 will, therefore, be

e-energized, permitting pawl 37 to remain in engagement with ratchet 36, so as'to hold damper 30 in any position to which it may be moved by operation of crank 35. Upon off the flow or gas through the 'precipitator.

As the weight member 41 drops, the arm 42 thereon engages arm 59 and causes contact to 1 be broken-between contact members 56 and 57 thus opening the circuit and preventing the continued drawing of current frombattery 53.

As soon as the power PP 'y to the P cipitator is again established, the damper may again be operated to open position, and

since the contact member 46will then be held by electromagnet 26 out of engagement with contact 45, the pawl 37 will again be held by spring 39 in engagement with ratchet 36.

It will of course be understood that many other arrangements may-be substituted for] the specific form above described, for causing the damper to close when the current in the .precipitator circuit decreases below the predetermined value, this particular form being shown only by way of example.

- I claim:

1. In combination with an electrical precipitator and with an electric circuit for supplying current thereto and means for passage of gas therethrough, a damper in said gas passage vmeans, and meansincluded in said circuit and. operable upon a predetermined decrease in current flow'insaid circuit to cause said damper closed position.

2'. In combination with an electrical p'recipitator and with an electric circuit for supplying current thereto and means for passage of gas therethrough, a damper in said gas passage means, an electromagnet included in said circuit, and means controlled by said electromagnet and operable when the current flow in said electromagnet falls to a certain predetermined value to cause said therefor and means for passage of gas therethrough, a damper in said gas passage means,

catch means tending to hold said damper in to be moved to openpo'sition and means for releasing said catch means when the current in said ciramass:

cuit falls to a certain value, said damper being automaticall movable to closed position upon such're ease of said catch means.

4. In an electrical precipitator, the combination with a treater chamber, an electrode system in said chamber, an electric circuit for supplyin currentto said system and an inlet and out et flue for passing gas through t e said chamber, of means controlled by flow of current in said circuit andoperable when said current falls to a predetermined value to prevent the flow of gas through said chamber. a I

5. The combination with an electrical precipitator having an electric circuit for sup-1 plying current thereto and means for the passage of gas therethrough, of a damper in said gas passage means, means tending to close said damper, a latch for normally retaining said damper in open position, and means including an electromagnet in said electric circuit for tripping said latch when the current supplied to said. precipitator falls to a certain predetermined value. v

In testimony whereof I havehereunto subscribed my name this 3d day ofJuly, 1928.

WALTHER DEUTSOH.

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