Abstract: A rapper for use in vibrating parts of an electrostatic precipitator by utilizing an impact force. An anvil is connected to a part of an electrostatic precipitator, such as, a section of electrodes either discharge electrodes or collecting plates or electrodes. A striker is engageable with an impact force on the anvil for vibrating the anvil as a result of the striker applying an impact force to the anvil. The vibration of the anvil is transmitted to the part. An elongated connector has one end connected to the striker. Crank means is connected to the elongated connector for raising the striker above the anvil and allowing the striker to drop into impact engagement with the anvil vibrating the anvil and the part of the electrostatic precipitator.