Patent ID: 9329069
Filing Date: 2016-05-03
CPC Classification: G01F

Claim Text:
1. A system for determining a blowdown condition in a liquid column, the system comprising: a column operable to be fluidly connected to a vessel for holding a liquid so that the level of liquid in the column corresponds to the level of liquid in the vessel, the column including a housing and a plurality of probes, the housing having a first end and a second end, the probes being operable to be inserted at least partially into the housing, the probes being spaced apart in the housing between the first end and the second end; a control unit operable to be electrically connected to each probe, the control unit configured to receive probe readings from each probe, the control unit configured to determine whether each probe is in liquid or in steam and to further determine whether a blowdown condition exists by comparing the probe readings to a plurality of parameters, the control unit using the probe readings, the plurality of parameters, a blowdown timer, and a blowdown flag in determining whether each probe is in liquid or in steam and in further determining whether the blowdown condition exists, the plurality of parameters including a good steam reading, an offset upper threshold, a blowdown upper threshold, a steam/liquid threshold, a blowdown lower threshold, an offset lower threshold, and a good liquid reading, wherein: an output device operable to be electrically connected to the control unit, the output device configured to signal whether each probe is in liquid or in steam and to further signal whether the blowdown condition exists; wherein, when a probe reading for a probe is at or between the offset upper threshold and the offset lower threshold, the blowdown timer is started; wherein, after the blowdown timer is started, when each subsequent probe reading for the probe is at or between the offset upper threshold and the offset lower threshold for a predetermined period of time, the blowdown flag is set; and wherein, after the blowdown flag is set, when a subsequent probe reading for the probe is at or between the blowdown upper threshold and the blowdown lower threshold, the output device signals that the blowdown condition exists.