Stable-heating heating equipment, furnace cooling method thereof and method for detecting burning loss condition in billet heating

The invention belongs to the technical field of cold air suction prevention of heating furnaces, and particularly relates to a heating device stable in heating, a furnace cooling method of the heating device stable in heating and a method for detecting the burning loss condition in the heating process of a steel billet. The first end is detachably connected with the slag discharging opening, and the second end is open; the fan is arranged in the deslagging connecting pipe and is close to the second end of the deslagging connecting pipe; the two ends of the main shaft penetrate through the deslagging connecting pipe respectively and extend outwards, and the fan blades are arranged in the circumferential direction of the main shaft. The upper end of the guide plate is in contact with the inner wall of one side of the deslagging connecting pipe, the guide plate is obliquely arranged in the deslagging connecting pipe and is integrally close to the first end of the deslagging connecting pipe, and a gap is reserved