US 2756838 A
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y 1956 M. ROBERTS ELECTRICAL PRECIPITATION APPARATUS Filed 00 28, 1954 l N VEN TOR LAWRENCE M. ROBERTS ATTORNEY atmospheric pressure to nited States Patent 2,756,838 ELECTRICAL PRECIPITATION APPARATUS Lawrence M. Roberts, Bound Brook, N. J., assignor to Research Corporation, New York, N. Y., a corporation of New York Application October 28, 1954, Serial No. 465,317 5 Claims. (Cl. 1837) This invention relates to electrical precipitators and in particular to means whereby electrical precipitation apparatus may be employed in modern high pressure reaction systems. A major engineering difficulty in subjecting gases maintained under high pressure to electrical precipitation treatment is a lack of a satisfactory insulating seal which allows high voltage to be conducted from the precipitator operating under elevated pressures. In general, insulating bushings employed in standard electrical precipitation equipment will not withstand pressures which are appreciably over 100 pounds per square inch without serious leakage of gas.
it is a primary object of the present invention to provide a system whereby standard insulating bushings of the type generally employed in low pressure precipitation equipment may be utilized on electrical precipitators adapted to be operated at high pressures.
It is a further object of the invention to provide such a system that is simple as to its parts, economically feasible to construct, and dependable in operation.
A further object is to provide such a system which may be readily installed on existing electrical precipitation apparatus when it is desired to convert such apparatus to high pressure operation.
Another object of the invention is to provide such a system which may be very satisfactorily used on precipitator installations operating under substantial range of pressures.
These and other objects and advantages are provided in an electrostatic precipitator adapted to operate at super atmospheric pressures including a shell having complementary discharge and collecting electrodes and a source of high voltage electricity, means for energizing the complementary electrodes comprising an insulator housing, partitions dividing the housing into a plurality of insulator compartments arranged in succession with respect to the precipitator shell, high voltage inlet bushings providing an electrical conductive path from the atmosphere through successive insulator compartments to the interior of the precipitator shell, and means for maintaining a predetermined pressure differential in each successive insulator compartment whereby the pressure differential between successive insulator compartments is maintained within the operating characteristics of the insulator bush- Ings.
The invention will be more particularly described with reference to the accompanying drawing of a preferred form of the apparatus of the present invention in vertical section.
Referring to the drawing, static precipitator having a and an insulator housing shell 16 are arranged collecting electrodes electrodes 13.
Each of the discharge electrodes 18 is suspended from a bus bar 29 supported within an insulator compartment 23 by means of insulators 24. An opening 26 is prois the shell of an electrogas inlet 12, a gas outlet 14 15. Within the precipitator a plurality of extended surface 16 and complementary discharge 2,756,838 Patented July 31, 1956 vided between the insulator compartment 22 and the interior of the precipitator shell 10 to provide electrical clearance for the vertical electrical conductive support member 28.
A second insulator compartment 30 is positioned in abutting arrangement with the insulator compartment 22 and sealed therefrom by partition 31, while a third insulator compartment 32 is arranged in abutting arrange ment with respect to insulator compartment 30 and sealed therefrom by partition 33.
Thus it is seen that insulator housing 15 is divided by partitions 31 and 33 into a plurality of insulator compartments 22, 30 and 32 arranged in succession with respect to the precipitator shell 10.
Within each of the insulator compartments 22, 30 and 32 are provided insulator bushings generally designated 34 having electrical conductive conduits 36 sealed therein whereby high voltage electricity may be conducted from a source outside of the electrical precipitator and not shown in the drawing to the discharge electrodes 18 within the precipitator shell 10.
The employment of three successive and abutting insulator compartments as shown in the drawing is for illustrative purposes only. It will be apparent from the following description of the invention that the number of successive insulator compartments employed on a parpressure at which the electrostatic precipitator is to be operated and the particular operating characteristics of the bushings 34. For example, if the precipitator is to be operated at pressures not exceeding 300 pounds per square inch and the insulator bushings 34 are constructed to withstand, without leakage, pressures of about to pounds per square inch the illustrated three insulator compartments would be sufficient for the proper operation of the precipitator as a pressure differential not exceeding 100 pounds pressure per square inch may be maintained without leakage of the insulator bushings in successive insulator compartments.
In order to maintain the desired predetermined pressure in the insulator compartments 22, 30 and 32 a source of high pressure inert or compatible gas generally designated 38 is connected to each compartment 22, 30 and .32 through primary conduit 40 and branch conduits 42, 44 and 46.
Each of the branch conduits 42, 44 and 46 is provided with an electrically controlled pressure reducing valve designated 48, 50 and 52 respectively. The pressure, of the source of fluid pressure 38, is maintained at least slightly greater than the pressure at which the precipitator is intended to be operated, and each pressure reducing valve 48, 50 and 52 is adjusted to maintain a predetermined pressure within the insulator compartments 22, 30 and 32.
For example, if the precipitator is adapted to treat gases at a pressure of about 300 pounds per square inch the pressure of the fluid pressure at source 33 should be slightly in excess thereof whereby insulator compartment 22 may be maintained at a pressure of, for example, 305 pounds so that a slight excess of pressure in the insulator compartment prevents the entry thereinto of the gases being treated within the precipitator shell 16. Valve 50 would then be regulated to maintain a pressure in insulator compartment 30 of about 200 pounds whereby the pressure differential between insulator compartment 22 and insulator compartment 30 would be about 100 pounds or within the operating characteristics of the inlet bushing 34. Valve 52 would be adjusted to maintain a pressure of about 100 pounds per square inch in insulator compartment 32 whereby the pressure differential between insulator compartments 32 and 3t) and insulator 3 compartment 32 and the atmosphere would not exceed about 100 pounds pressure.
In order to maintain the pressure in insulator compartment 22 slightly greater than the operating pressure of the electrostatic precipitator so that-flow of gas through the orifice 26 is from the insulator compartment 22 to the interior of the precipitator shell.10 it is desirable to provide a pressure sensing means 54 within the shell of the precipitator. The pressure sensing means 54 is electrically connected to the adjustable pressure reducing valve 48 by electrical conduits 56. On installations where the operating pressure of the precipitator may vary over a substantial range, it has been found to be advantageous to provide automatic regulating means for the pressure reducing valves 50 and 52 of insulator compartments 30 and 32. The pressure sensing units are shown in the drawing at 58 and 60 and connected respectively to pressure reducing valves 50 and 52 by electrical conduits 62 and 64.
From the foregoing description it will be seen that the present invention provides very satisfactory means for energizing the complementary electrodes of an electrostatic precipitator for operation at super atmospheric pressures wherein the pressure differential in the insulator compartments does not exceed the predetermined operating characteristics of the electrical inlet bushings, whereby the aims objects and advantages of the present invention are fully accomplished.
1. In an electrostatic precipitator for operation at super atmpospheric pressures including a shell containing complementary discharge and collecting electrodes and a source of high voltage electricty, means for energizing the complementary electrodes comprising an insulator housing, partitions dividing the housing into a plurality of insulator compartments arranged in succession with respect to the precipitator shell, high voltage inlet bushings providing an electrical conductive path from atmosphere through successive insulator compartments to the electrodes within the precipitator shell, and means for maintaining predetermined pressure differentials between successive insulator compartments.
2. In an electrostatic precipitator for operation at super atmospheric pressures including a shell containing complementary discharge and collecting electrodes and a sure gas, conduit means connecting said source of high pressure gas to each of the insulator compartments, and pressure reducing valves in the conduits to each of the insulator compartments.
3. The invention defined in claim 2 including pressure sensing means in the shell of the electrostatic precipitator, and means connecting said pressure sensing means to the pressure reducing valve in the insulator compartment immediately adjacent the precipitator shell.
4. The invention defined in claim 2 including pressure sensing means in the precipitator shell, means connecting said pressure sensing means to the pressure reducing valve in the insulator compartment immediately adjacent the precipitator shell, and means connecting the pressure reducing valves in each succeeding insulator compartment to pressure sensing means positioned in the insulator compartment immediately adjacent thereto.
5. The invention defined in claim 2 wherein the high voltage inlet bushings are supported in the partitions dividing the said housing into the plurality of insulator compartments.
References Cited in the file of this patent UNITED STATES PATENTS