GB1575404A

GB1575404A - Corona discharge electrodes

Info

Publication number: GB1575404A
Application number: GB1442976A
Authority: GB
Original assignee: STURTEVANT GAS CLEANING Ltd
Current assignee: STURTEVANT GAS CLEANING Ltd
Priority date: 1977-03-15
Filing date: 1977-03-15
Publication date: 1980-09-24

Description

(54) IMPROVEMENTS IN AND RELATING TO CORONA DISCHARGE ELECTRODES (71) We, STURTEVANT GAS CLEANING LIMITED, a British Company of Mallinson House, 321 Chase Road, Southgate, London, N.14, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly describd in and by the following statement: - The present invention relates to corona discharge electrodes for use in electrostatic precipitation.

According to the present invention there is provided a corona discharge electrode for use in electrostatic precipitation, the electrode comprising an elongate supporting body and a plurality of elements extending from and connected to the body, each element providing at least one corona discharge tip, wherein the body is made from a strip of metal and has longitudinally extending central stiffening portion, and coplanar longitudinally extending edge portions to each side of the central stiffening portion and from which the elements extend, the central stiffening portion having an open transverse section, including a generally channel-shaped part, and extending to each side of the plane of the edge portions.

In one embodiment, the stiffening portion is longitudinally corrugated so as to provide an open transverse section having two oppositely directed channel-shaped parts.

The elements may be formed integrally with such planar edge portion of the body or may be formed separately and fixed to the respective planar edge portion.

The elements may be formed integrally with the body by cutting the longitudinally extending edge portions and bending the parts defined thereby and forming the elements out of the plane of thedge portion along lines intersecting the longitudinal direction of the body. Adjacent parts may be bent in opposite directions.

In the preferred embodiments, the cuts made in each edge portion are straight, parallel to each other, and inclined to the longitudinal direction, and the parts defined thereby are bent about lines joining the adjacent ends of adjacent cuts. Advantageously the bending lines are perpendicular to the longitudinal direction.

The present invention will be more fully understood from the following description of embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a transverse section through an embodiment of electrode according to the present invention; Figures 2 and 3 are perpendicular side views of the electrode of Figure 1; Figures 4 and 5 are views corresponding to those of Figures 2 and 3 of one end of the electrode of Figure 1; Figure 6 is a diagrammatic plan view of another electrode according to the invention; Figure 7 is a transverse section through the electrode of Figure 6; Figure 8 is a side view of the electrode of Figure 6; Figure 9 is a plan view of an element of the electrode of Figure 7 during manufacture; Figure 10 is a section on the line X-X of Figure 9; and Figures 11 and 12 are plan and side views of the finished element shown in Figure 9.

The corona discharge electrode shown in Figures 1 to 5 comprises an elongate supporting body 1 made from a strip of steel which is shaped to provide the body with a longitudinally extending central stiffening portion 2 and coplanar longitudinal edge portions 3, The stiffening portion 2 is longitudinally corrugated so as to extend to each side of the plate of the edge portion and to provide it with an open transverse sec tion having two oppositely directed channel-shaped parts. The electrode also comprises a plurality of elements 4 each providing a corona discharge tip and extending from the edge portions 3 of the body 1.

In this embodiment, the elements 4 are integral with the body 1 and are formed by making a plurality of inclined, parallel cuts 5 along the edge of each portion 3.

The-parts defined by the cuts are connected integrally to the body 1, and are bent out of the plane of the edge portion about, lines 6 joining adjacent ends of adjacent cuts and intersecting the longitudinal direction of the body 1. Adjacent parts are bent in opposite directions (Figures 1 and 3). In the illustrated embodiment, the lines 6 are perpendicular to the longitudinal direction of the electrode. It will however be appreciated that the lines 6 could be inclined to the longitudinal direction.

For mounting the electrode, at each end of the electrode the body is centrally cut away as shown in Figure 4 and the remaining portions 3 are provided with fixing holes 7 by which it can be connected to a part 8 (Figure 5) of a precipitator framework.

The above described electrode is highly mechanically stable but is yet easy and cheap to make since it can be simply cold rolled and machine pressed from steel strip.

The above described electrode is also described and claimed in copending application No. 35498/78 (Serial No. 1575404).

The corona discharge electrode shown in Figures 6 to 12 is similar to that shown in Figures 1 to 5 in that it comprises the same supporting body 1 with a central stiffening section 2 and planar edge portions 3. However, in this embodiment the elements 9 are made separately and are fixed at longitudinally spaced intervals to the edge portions 3, for example by spot welding. Each element 9 has a substantially planar body by which it is fixed to the edge portion 3 and two corona discharge tips 10 which are bent in opposite directions out of the plane of the element. To provide the tips 10, the free end of each element 9 is generally V shaped, the arms of the V forming the discharge tips 10. For strengthening purposes, each element has a generally Y-shaped depression 11, the arms of which extend along the tips of the element.

The above described electrode is also easy and relatively cheap to manufacture but will be less so than the first embodiment insofar as the manufacture includes the step of fixing the elements to the body.

However since each element provides two discharge tips, only half the number of elements are required for this embodiment than are required for the first embodiment.

WHAT WE CLAIM IS: - 1. A corona discharge electrode for use in electrostatic precipitation, the electrode comprising an elongate supporting body and a plurality of elements extending from and connected to the body, each element providing at least one corona discharge tip, wherein the body is made from a strip of metal and has a longitudinally extending central stiffening portion and coplanar longitudinally extending edge portions to each side of the central stiffening portion and from which the elements extend, the central stiffening portion having an open transverse section, including a generally channel-shaped part, and extending to each side of the plane of the edge portions.

2. An electrode according to claim 1, wherein the central stiffening portion is longitudinally corrugated so as to provide an open transverse section having two oppositely directed channel-shaped parts.

3. An electrode according to either claim 1 or claim 2, wherein the elements are formed separately and fixed to the respective edge portion.

4. An electrode according to claim 3, wherein each element provides a pair of corona discharge tips.

5. An electrode according to claim 4, wherein each element comprises a substantially planar body by which it is fixed to the respective edge portion, and a pair of side by side tips which are bent in opposite directions out of the plane of the body.

6. An electrode according to either claim 1 or claim 2, wherein the elements are formed integrally with each planar edge portion of the body.

7. An electrode according to claim 6, wherein each element provides a single discharge tip, and the elements are formed by cutting the respective edge portion, the parts defined hereby being bent out of the plane of the edge portion along lines intersecting the longitudinal direction of the body.

8. An electrode according to either claim 6 or claim 7, wherein the elements are formed by forming cuts in each edge portion, which cuts are straight, parallel to each other, and inclined to the longitudinal direction of the electrode, and the parts defined thereby are bent about lines, each line joining one end of one cut to the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. tion having two oppositely directed channel-shaped parts. The electrode also comprises a plurality of elements 4 each providing a corona discharge tip and extending from the edge portions 3 of the body 1. In this embodiment, the elements 4 are integral with the body 1 and are formed by making a plurality of inclined, parallel cuts 5 along the edge of each portion 3. The-parts defined by the cuts are connected integrally to the body 1, and are bent out of the plane of the edge portion about, lines 6 joining adjacent ends of adjacent cuts and intersecting the longitudinal direction of the body 1. Adjacent parts are bent in opposite directions (Figures 1 and 3). In the illustrated embodiment, the lines 6 are perpendicular to the longitudinal direction of the electrode. It will however be appreciated that the lines 6 could be inclined to the longitudinal direction. For mounting the electrode, at each end of the electrode the body is centrally cut away as shown in Figure 4 and the remaining portions 3 are provided with fixing holes 7 by which it can be connected to a part 8 (Figure 5) of a precipitator framework. The above described electrode is highly mechanically stable but is yet easy and cheap to make since it can be simply cold rolled and machine pressed from steel strip. The above described electrode is also described and claimed in copending application No. 35498/78 (Serial No. 1575404). The corona discharge electrode shown in Figures 6 to 12 is similar to that shown in Figures 1 to 5 in that it comprises the same supporting body 1 with a central stiffening section 2 and planar edge portions 3. However, in this embodiment the elements 9 are made separately and are fixed at longitudinally spaced intervals to the edge portions 3, for example by spot welding. Each element 9 has a substantially planar body by which it is fixed to the edge portion 3 and two corona discharge tips 10 which are bent in opposite directions out of the plane of the element. To provide the tips 10, the free end of each element 9 is generally V shaped, the arms of the V forming the discharge tips 10. For strengthening purposes, each element has a generally Y-shaped depression 11, the arms of which extend along the tips of the element. The above described electrode is also easy and relatively cheap to manufacture but will be less so than the first embodiment insofar as the manufacture includes the step of fixing the elements to the body. However since each element provides two discharge tips, only half the number of elements are required for this embodiment than are required for the first embodiment. WHAT WE CLAIM IS: -

1. A corona discharge electrode for use in electrostatic precipitation, the electrode comprising an elongate supporting body and a plurality of elements extending from and connected to the body, each element providing at least one corona discharge tip, wherein the body is made from a strip of metal and has a longitudinally extending central stiffening portion and coplanar longitudinally extending edge portions to each side of the central stiffening portion and from which the elements extend, the central stiffening portion having an open transverse section, including a generally channel-shaped part, and extending to each side of the plane of the edge portions.

other end of an adjacent cut.

9. An electrode according to either claim 7 or claim 8, wherein the lines of bending are substantially perpendicular to the longitudinal direction.

10. A corona discharge electrode substantially as herein described with reference to Figures 1 to 5 or Figures 6 to 12 of the accompanying drawings.