Electrostatic precipitator rapper control system rapper plunger lift indicator
AssigneeResearch-Cottrell, Inc.
InventorWilliam W. Andrews
Life of this patent
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Abstract
A rapper plunger displacement indicator for an electrostatic rapper control system of the type which supplies a pulse of controlled energy to the rapper coils. Means are provided for sensing current supplied to each rapper coil during the controlled energy pulse. The resultant sensed current is integrated with respect to time over the period of the pulse of controlled energy, and the result of the integration indicates plunger displacement. In a system where a short boost pulse of full lift energy is supplied immediately prior to the lift pulse of controlled energy for enhanced control accuracy, the integration is performed only during the controlled energy pulse, thus ignoring the boost pulse.
Claims11
A rapper plunger displacement indicator for an electrostatic precipitator rapper control system of the type which supplies a pulse of controlled energy to a rapper generally having a movable plunger biased towards an impact and resting position and an electromagnetic means for displacing the plunger away from the impact and resting position in response to the controlled energy pulse and then releasing the plunger, said displacement indicator comprising:
- means for sensing current supplied to the rapper electromagnetic means;
- and
- means for integrating the sensed current with respect to time over the period of the pulse of controlled energy, the result of the integration being indicative of plunger displacement.
A rapper control system for an electrostatic precipitator including a rapper of the type having a movable plunger biased towards an impact and resting position and having electromagnetic means for displacing the plunger away from the impact and resting position, rapping intensity depending upon the distance of plunger displacement before release, said control system comprising:
- means for supplying the rapper electromagnetic means with an electrical energy boost pulse having a predetermined relatively high power level and predetermined duration sufficient to overcome plunger initial sticking forces and to just slightly displace the rapper plunger from its impact and resting position;
- means for supplying the rapper electromagnetic means with an electrical energy pulse of controlled energy for displacing the rapper plunger to a desired position immediately following the boost pulse;
- means for sensing current supplied to the rapper electromagnetic means during the pulse of controlled energy;
- and
- means for integrating the sensed current with respect to time over the period of the pulse of controlled energy, the result of the integration being indicative of plunger displacement before release and of rapping intensity.
A method of determining the displacement of the plunger of an electrostatic precipitator rapper, the rapper being of the type having a plunger and an electromagnetic coil for displacing the plunger, rapping intensity depending upon plunger displacement, said method comprising:
- sensing current through the rapper electromagnetic coil;
- and
- integrating the sensed current with respect to time over the period of the energization pulse, the result of the integration being indicative of plunger displacement.
Dependencies are inferred from the claim text.