Flame sense assembly with ground screen
View Patent ↗A flame sense assembly ( 100 ) includes a flame sense electrode having a sense rod ( 108 ), at least a portion of the sense rod ( 108 ) for placement in a flame area; and an electrically conductive ground screen ( 110 ) for electrical connection to ground, at least a portion of the ground screen ( 110 ) for placement in the flame area; wherein the ground screen ( 110 ) is positioned relative to the sense rod ( 108 ) to allow an electric current to pass between the sense rod ( 108 ) to the ground screen ( 110 ) in the presence of a flame.
1. A flame sense assembly comprising:
a flame sense electrode having a sense rod, at least a portion of the sense rod for placement in a flame area; and
an electrically conductive ground screen for electrical connection to ground, at least a portion of the ground screen for placement in the flame area;
wherein the ground screen is positioned relative to the sense rod to allow an electric current to pass between the sense rod to the ground screen in the presence of a flame;
wherein the ground screen includes a first portion having a first opening for receiving the flame sense electrode and a second portion extending from the first portion, at least part of the second portion for placement in the flame area;
a second flame sense electrode having a second sense rod, at least a portion of the second sense rod for placement in the flame area;
the first portion of the ground screen having a second opening for receiving the second flame sense electrode.
2. The flame sense assembly of claim 1 wherein:
the second portion of the ground screen includes at least one opening therethrough for allowing passage of a flame.
3. The flame sense assembly of claim 1 further comprising:
a ground rod for electrically connecting the ground screen to electrical ground.
4. The flame sense assembly of claim 3 wherein:
the ground rod is mechanically secured to the ground screen.
5. The flame sense assembly of claim 3 further comprising:
an electrically conductive bracket for electrical connection to an electrically grounded housing, the ground rod electrically connected to the bracket.
6. The flame sense assembly of claim 3 wherein:
the ground rod is positioned proximate a distal end of the sense rod to define a spark gap.
7. The flame sense assembly of claim 3 wherein:
the ground rod is a pilot tube, the pilot tube to provide fuel for a pilot flame.
8. The flame sense assembly of claim 7 wherein:
the pilot tube is positioned proximate a distal end of the sense rod to define a spark gap.
9. The flame sense assembly of claim 7 wherein:
the ground screen is mechanically secured to the pilot tube.
10. The flame sense assembly of claim 1 further comprising:
an electrically conductive bracket for electrical connection to an electrically grounded housing, the ground screen electrically connected to the bracket.
11. The flame sense assembly of claim 1 wherein: the second portion of the ground screen is planar.
12. The flame sense assembly of claim 1 wherein:
the second portion of the ground screen has a length, width and height, the length and width each being greater than the height.
13. The flame sense assembly of claim 1 wherein:
the second portion of the ground screen is polygonal.