In fossil boilers and steam generator of fossil boilers and nuclear power plants, a son-air detector using ultrasonic transducers is employed with a glandless motor pump which may have a vertical top vent pipe to ascertain with fast response if the vent pipe has liquid or not. In the glandless motor pump, the pumped primary liquid per se is used for lubricating the bearings of the motor, whereby, if the lubricating liquid is absent, the motor operation should not be continued. For redundancy, a second transducer may be used, whereby when both the transducers are connected to simultaneously indicate absence of liquid in the vent pipe, suitable corrective action is initiated. A vent pipe filled with liquid will transmit ultrasonic bursts (provided by the transducer) through the liquid, so that the ultrasonic waves are reflected back. An empty vent pipe will not reflect the ultrasonic waves which would simply be dissipated. The motor pump also uses a wrap around type heat exchanger cooler which takes in plain cool water from the outside to cool the outside of the stator. The motor pump optionally is provided with a bearing water thermometer and a purge line.
A system for dissipating heat from a power supply enclosed within a housing having an air inlet and outlet. The system includes fans disposed in a plenum structure adapted to fit over the housing to thereby establish air communication between the fans and the housing inlet so that operation of the fans causes air to flow through the inlet, the power supply, and out through the outlet, thereby dissipating heat from the power supply. Each fan is operable independent of any other of the fans. The relationship between the fans may be serial, parallel, or a combination of serial and parallel. The fans are monitored to detect failure of any of the fans and, upon such detection, an alert is activated.
