Abstract: A method and apparatus for removing salt-cake deposits from boiler surfaces found in the upper areas of recovery furnaces. More specifically, in the Kraft papermaking process, a black liquor is produced which is combusted in a recovery furnace in order to supply heat for steam generation. Hot flue gases containing inorganic salt combustion by-products are passed through and around boiler heat exchange tubes found in the upper furnace areas. Deposits of the inorganic salt components are formed on the heat exchange tubes, thus insulating the tubes from the hot flue gases and resulting in lower heat recovery boiler efficiency.