Abstract: A slag monitoring device 100 for a coal gasifier includes a slag hole camera 11 that observes a slag hole 3 from which molten slag flows out, a water surface camera 12 that observes a situation in which the slag flowing out from the slag hole 3 falls onto a water surface 5H of cooling water 5, a falling sound sensor 13 that observes a sound of the slag falling onto the water surface 5H, and a processing device 20 that determines a solidification and adhesion position of the slag based on an opening area of the slag hole 3 observed by the slag hole camera 11 and falling lines and falling positions of the slag observed by the water surface camera.

Abstract: A leading end located in a two-stage entrained-flow bed coal gasifier has a double-walled structure including an outer cylinder and an inner cylinder, and cooling water for cooling the leading end is supplied through an interior of the inner cylinder to cool the leading end and is then returned to a base end through a space formed between the outer cylinder and the inner cylinder. The space formed between the outer cylinder and the inner cylinder has a smaller channel area than the interior of the inner cylinder, and a swirling flow along a guide formed on an outer circumferential surface of the inner cylinder and a substantially linear flow in a longitudinal direction of the outer cylinder and the inner cylinder are applied to the cooling water returned to the base end through the space formed between the outer cylinder and the inner cylinder.