Air Pollution Controls

Rapper Controls

Devices, generically called rappers, are used for cleaning the internals (collecting plates and discharge electrodes) of the precipitator.  These rappers are actually single impulse type drop hammers, multi impulse type hammers, electric vibrators, or air solenoids (that control pneumatic vibrators or sonic horns).

The rapper control energizes these devices for a programmable time period and intensity.  The time period and intensity have a direct affect on the efficiency of the precipitator.  If the internals are not kept clean the stack opacity will rise.  If the internals are over cleaned the stack opacity will rise.  It is therefore essential that the microprocessor rapper control be flexible enough to allow optimization of the rapping cycle and intensity.

Redkoh’s MRC-NT microprocessor based rapper control is the most flexible control on the market.  Clock timing (repetition time) by Individual rapper groups, or globally is provided.  Rapper intensity (plunger lift) can be adjusted by individual rapper, by rapper group, or globally.  Six independent rapper programs can be stored for use under varying operating conditions (such as low load, various fuels, boiler tube leak, etc.).  The rapper control(s) can communicate with TR controls for power down rapping, and with a DCS/PLC for data logging and contro

If a device failure occurs, the control indicates the device number, and the cause of the failure, such as open circuit or over current, minimizing maintenance time.  Modularized construction and plug in control card further reduces maintenance time.

Rapper controls should be evaluated every ten years or so to make sure they are up to date and contain the latest strategies for optimal precipitator cleaning.

New controls for back fitting into existing rapper control cabinets can be provided as well as new controls and cabinets.


MRC-NT Microprocessor Rapper and Vibrator Controls Brochure
MRC-NT Microprocessor Rapper Control Troubleshooting Guide
Redkoh - MRC-NT Rapper Control Training
Generic MRC-NT Circuit Diagram DWG

Generic MRC-NT GA Cabinet DWG