| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method for solid fuel enabling water contained in slurry to be efficiently evaporated by increasing heat exchange efficiency.SOLUTION: The production method for solid fuel of the present invention comprises a step of preparing slurry by mixing powdery low-grade coal and oil, a step of evaporating water contained in the slurry by heating it, and a step of subjecting the slurry after the evaporation step to solid-liquid separation. The evaporation step includes a step of preheating the slurry in a first circulation path, and a step of heating the preheated slurry in a second circulation path different from the first circulation path. Preferably, in the preheating step and the heating step, a multitubular heat exchanger is used of which the shell side is supplied with a heating medium and of which the tubular side is supplied with the slurry. Preferably, process steam produced in the evaporation step is used as a heating medium for one of the preheating step and the heating step, while steam introduced from outside is used as a heating medium for the other step.SELECTED DRAWING: Figure 1 |
