Abstract: A flame detection device that uses a breakthrough voltage across a pair of electrodes located in a flame zone to detect the presence of a flame. The flame detection device may be used with a burner that is part of a furnace in a central heating system for a home or building. Unlike conventional flame detection devices that measure ionization current in a flame, the flame detection device detects a flame by determining the voltage required for a spark event across a spark gap located in a flame zone (also referred to as the breakthrough voltage), and evaluating the breakthrough voltage and/or its various characteristics to detect the presence or absence of a flame. According to one example, the flame detection device includes a power supply, an ignition unit, output wires, insulators, and electrodes.

Abstract: A bushing formed of different alloys selected to accommodate different operating conditions is provided. For example, the bushing could include an iron-based alloy in a portion of the bushing exposed to lower temperatures, and a cobalt-based alloy in a portion of the bushing exposed to higher temperatures. The first and second alloys could be axially or radially aligned. The iron based alloy includes 10 to 30 wt % Cr, 0 to 21 wt % Ni, 0 to 10 wt % Mo, 0 to 5 wt % W, 0 to 3 wt % C, 0 to 4 wt % V, 0 to 20 wt % Co, and a balance of Fe; and the cobalt based alloy includes 10 to 30 wt % Cr, 5 to 21 wt % Ni, 0 to 10 wt % Mo, 0 to 10 wt % W, 0 to 3 wt % V, 0.5 to 3 wt % C, and a balance of Co.

Abstract: A bushing formed of different alloys selected to accommodate different operating conditions is provided. For example, the bushing could include an iron-based alloy in a portion of the bushing exposed to lower temperatures, and a cobalt-based alloy in a portion of the bushing exposed to higher temperatures. The first and second alloys could be axially or radially aligned. The iron based alloy includes 10 to 30 wt % Cr, 0 to 21 wt % Ni, 0 to 10 wt % Mo, 0 to 5 wt % W, 0 to 3 wt % C, 0 to 4 wt % V, 0 to 20 wt % Co, and a balance of Fe; and the cobalt based alloy includes 10 to 30 wt % Cr, 5 to 21 wt % Ni, 0 to 10 wt % Mo, 0 to 10 wt % W, 0 to 3 wt % V, 0.5 to 3 wt % C, and a balance of Co.