Device or system used to return a system or a component of it to full strength in a chemical process; examples are a furnace to burn carbon from a catalyst, a tower to wash impurities from clay, and a flush system to clean off the surface of filter media.

1. A circuit that repeatedly supplies current to a display or memory device to prevent data from decaying.

2. See <<repeater>>

A device used with hot-air engines and gas-burning furnaces which transfers heat from effluent gases to incoming air or gas.