Rappers

Dust that has accumulated on collection and discharge electrodes is removed by rapping. Dust deposits are generally dislodged by mechanical impulses, or vibrations, imparted to the electrodes. A rapping system is designed so that rapping intensity and frequency can be adjusted for varying operational conditions. Once the operating conditions are set, the system must be capable of maintaining uniform rapping for a long time. Collection electrodes are rapped by hammer/anvil or magnetic impulse systems. Rigid frame discharge electrodes are rapped by tumbling hammers and wires are rapped by vibrators. As stated previously, liquid sprays are also used (instead of rapping) to remove collected particles form both tubes and plates.