Particle resistant enclosure for dead tank circuit breaker
View Patent ↗A tank for a circuit breaker has a body defining an interior volume and having opposing ends. An flange is at each end of the body with the flanges defining a central longitudinal axis of the body. The body has an internal surface defining a top portion of the tank disposed substantially above the axis and defining a bottom portion of the tank disposed substantially below the axis. The top portion is spaced from the axis as defined by at least a first radius from the axis. The bottom portion is spaced from the axis as defined by at least a second radius from axis. The second radius is greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation.
1. A tank for a circuit breaker, the tank comprising:
an integral body defining an interior volume and having opposing ends, and
an annular flange at each end of the body, the flanges defining a central longitudinal axis of the body,
wherein the body has a substantially continuous internal surface defining a top portion of the tank disposed substantially above the central longitudinal axis and in an upper half of the body and the body defining a bottom portion of the tank disposed substantially below the central longitudinal axis and in a bottom half of the body, the top portion being spaced from the central axis as defined by at least a first radius from the central longitudinal axis, and the bottom portion is spaced from the central axis as defined by at least a second radius from central longitudinal axis, with the second radius being greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation,
wherein the body includes transition portions defining a smooth transition between the top portion and the bottom portion, each transition portion being defined by transition radii that are sized so that the first and second radii blend smoothly and wherein each transition portion extends into the upper half of the body.
2. The tank of claim 1 , wherein a dimension of the first radius is based on an impulse voltage of the circuit breaker and a dimension of the second radius is based on power frequency and nominal system voltage such that when the circuit breaker is energized, an electric field in the tank is sufficiently weak so as to not cause foreign charged particles to levitate from the bottom portion of the body.
3. The tank of claim 2 , wherein impulse voltage is BIL or chopped wave.
4. The tank of claim 2 , wherein the nominal voltage is 1 p.u. line to ground voltage of the circuit breaker.
5. The tank of claim 1 , wherein the body further includes a pair of bushing mounts integral there-with and in communication with the interior volume.
6. The tank of claim 1 , further comprising an interrupter disposed in the interior volume and having a longitudinal axis that is aligned with the central longitudinal axis.
7. A dead tank circuit breaker comprising:
a plurality of pole assemblies, each pole assembly including a first electrical conductor carried in a first bushing and a second electrical conductor carried in a second bushing, each pole assembly including a tank, and
a bell crank coupled to each tank,
wherein each tank comprises:
an integral body defining an interior volume and having opposing ends, and
an annular flange at each end of the body, the flanges defining a central longitudinal axis of the body,
wherein the body has a substantially continuous internal surface defining a top portion of the tank disposed substantially above the central longitudinal axis and in an upper half of the body and the body defining a bottom portion of the tank disposed substantially below the central longitudinal axis and in a bottom half of the body, the top portion being spaced from the central longitudinal axis as defined by at least a first radius from the central longitudinal axis, and the bottom portion is spaced from the central longitudinal axis as defined by at least a second radius from central longitudinal axis, with the second radius being greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation,
wherein the body includes transition portions defining a smooth transition between the top portion and the bottom portion, each transition portion being defined by transition radii that are sized so that the first and second radii blend smoothly and wherein each transition portion extends into the upper half of the body.
8. The circuit breaker of claim 7 , wherein a dimension of the first radius is based on an impulse voltage of the circuit breaker and a dimension of the second radius is based on power frequency and nominal system voltage such that when the circuit breaker is energized, an electric field in the tank is sufficiently weak so as to not cause foreign charged particles to levitate from the bottom portion of the body.
9. The circuit breaker of claim 8 , wherein impulse voltage is BIL or chopped wave.
10. The circuit breaker of claim 8 , wherein the nominal voltage is 1 p.u. line to ground voltage of the circuit breaker.
11. The circuit breaker of claim 7 , wherein the body further includes a pair of bushing mounts integral there-with and in communication with the interior volume.
12. The circuit breaker of claim 7 , further comprising an interrupter disposed in the interior volume and having a longitudinal axis that is aligned with the central longitudinal axis.