PURPOSE: To recover the sensible heat of a crude gas generated from a coke oven, by cooling a mixture of a tar flowing down heat transfer tubes with a gas with water spray, separating the cold mixture by the specific gravity, and feeding the resultant diluted tar having a low boiling point to the circulating tar.
CONSTITUTION: A crude gas (G2) generated from a coke oven is brought into contact with a circulating tar 11 charged into a wetted wall cooler 5 and made to flow in vertical heat transfer tubes 12 arranged in the wetted wall cooler 5 to carry out the heat exchange of the crude gas with a fluid flowing around the above-mentioned heat transfer tubes 12 and recover the sensible heat of the crude gas (G2). The resultant mixture of the tar flowing down the heat transfer tubes 12 with the gas is cooled with water spray in a water spray tank 15 and separated in a gas-liquid separation tank 17 by the specific gravity to give a diluted low-boiling tar, which is then fed to the above- mentioned circulating tar 11.
EFFECT: The viscosity of the circulating tar can be reduced without reducing the temperature of the circulating tar, and the following advantages can be obtained; Improvement in cooling performance, reduction in the power of the circulating pump, miniaturization of the apparatus and improved quality of recovered steam.
MAKINO KATSUAKI
TAODA KIYOMICHI
KUWATA TOKIO
NIPPON KOKAN KK