US 2874802 A
Description (OCR text may contain errors)
Feb. 24, 1959 s. GUSTAFSSON ET AL 2,874,802
METHOD FOR CLEANING 'IHE ELECTRODES IN ELECTRO-FILTERS Filed July 6, 1955 FIE. I.
0. 3 Mu 11. all f n m fl/ "J 7 v/m m M f m n 5 6r 1 l 3 IIIIPIHHHHHIIII United States Patent filic Patented Feb. 24, 1959 METHOD FOR CLEANING THE ELECTRODES IN ELECTRO-FILTERS Stig Gustafsson, Jonkoping, and Per-olof hnfeldt, Lidingo, Sweden, assignors to Aktiebolaget Svenska Flaktfabriken, Stockholm, Sweden Application July 6, 1955, Serial No. 520,344
Claims priority, application Sweden July 7, 1954 2 Claims. (Cl. 183-114) The present invention relates to a method for cleaning of the electrodes of electrical precipitators by flushing the electrodes with liquid. In electrical precipitators for gases which on the electrodes cause deposits which cannot be mechanically removed by vibrating or the like it is common to flush the electrodes. In order to avoid interruption of the operation of the precipitators during the flushing it has previously been necessary to use limited quantities of liquid whereby mainly the collecting electrodes have been subjected to said liquid. Because of this the flushing of said collecting electrodes has been unsatisfactory and, further, it has not been possible to remove the dust being accumulated on the emission electrodes.
It is an object of the method according to the invention to eliminate these drawbacks.
All of the objects of the invention, and a suitable apparatus to which the invention may be applied are set forth more fully hereinafter with reference to the accompanying drawing, wherein:
Fig. 1 is a longitudinal section through a precipitator equipped to perform the method of the present invention;
Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; and,
Fig. 3 is a sectional view taken on the line 3-3 of Fig. l.
The method is characterized in that the flushing is performed by means of two separate spray systems 11 and 14 in such a manner that the liquid is supplied in part continuously in the form of one or more curtains 16 of liquid atomized by spray nozzles 15 in the system 14, said curtains being perpendicular to the flow direction of the gas, and in part intermittently with greater intensity in form of similar vertical liquid curtains 17 which are parallel to the gas flow and are formed by nozzles or apertures in the system 11.
According to the invention the liquid particles in the continuous flushing system 14 are evenly distributed on the collecting electrodes 12 by the influence of the electrical field in spite of the fact that the quantity of liquid is limited to such an extent which is suitable for the uninterrupted running of the precipitator. By the cooperation between said continuous flushing system 14 and 2' the intermittent but intensive system 11, both the collecting electrodes 12 and the emission electrodes 9 will be thoroughly cleaned.
The illustrated apparatus comprises an electrical precipitator 7 having horizontal gas flow from the inlet 1 to the outlet 13 and being provided with one or more sections of vertical sheet-like collecting electrodes 12 arranged parallel to the gas flow and with intermediate spaced rows of emission electrodes 9. The emission electrodes 9 comprise wires stretched in conventional manner within supporting frames 8 which are supported in the casing 7 by insulators 6. The sheet-like collecting electrodes 12 are arranged intermediate the frames 8.
The continuous flushing system 14 may be connected to a supply pipe 2 by a branch conduit 3. The intermittent flushing system 11 may be connected to the supply pipe 2 by a branch conduit 5 having an automatic valve 4 therein which is actuated by a suitable timing device or the like which effects intermittent operation of the system 11.
While a particular precipitator is shown in the drawing, the invention may be applied to any other suitable precipitator within the scope of the following claims.
What we claim:
1. The method for cleaning electrodes in electrical precipitators having horizontal gas flow therein between vertical sheet-like collecting electrodes arranged parallel to the flow and intermediate rows of emission electrodes, comprising the steps of continuously causing the gas to flow horizontally through said precipitator and forming a vertical curtain of liquid perpendicular to the gas flow within said precipitator in advance of said collecting electrodes whereby liquid particles from said curtain are entrained in said flow and distributed to the collecting electrodes to partially liquify the deposit thereon and flush the same, the flushed deposit continuously flowing downward on said vertical electrodes transversely to said horizontal gas flow, and intermittently forming other curtains of atomized liquid parallel to the sheet-like collecting electrodes and the gas flow intermediate said electrodes to thoroughly clean both the emission and collecting electrodes.
2. A method according to claim 1 wherein the quantity of liquid in the continuous curtain is limited to an extent which is suitable for the uninterrupted running of the precipitator, and wherein further the operation of the intermittent curtain is more intensive than said continuous curtain.
References Cited in the file of this patent UNITED STATES PATENTS 1,329,737 Wolcott Feb. 3, 1920 1,329,817 Wolcott Feb. 3, 1920 1,905,993 Buff Apr. 25, 1933 2,171,617 Wintermute Sept. 5, 1939 2,748,889 Rcnwanz June 5, 1956