WATER TUBE BOILER

• Main Authors: KOBASHI TORU, KATSUMURA SHINICHIRO, USUI TOMOMASA
• Format: Patent
• Language: English
• Published: 16.01.1998
• Edition: 6
• Subjects: BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; METHODS OF STEAM GENERATION; STEAM BOILERS; STEAM GENERATION; WEAPONS

PROBLEM TO BE SOLVED: To perform the stable operation of a boiler by controlling the fluctuation in the drum level in switching a downcomer with a bypass pipe. SOLUTION: In a water tube boiler comprising at least a steam drum 3, a downcomer 4, an evaporative water tube 5, and a riser tube, a bypass tube for bypassing the downcomer 4 on the steam generating water tube side 5 of the downcomer 4 is branched, a directional control valve 12 is installed in the bypass tube together with a circulation pump 10, a forced circulation passage through the steam drum 3, the downcomer 4, the bypass tube, the circulating pump 10, the directional control valve 12, the evaporative water tube 5, the riser tube, and the steam drum 3 is formed by operating the circulation pump 10, the forced circulation passage is operated when the boiler is started operating, or the load is low, and the directional control valve 12 is gradually opened when the forced circulation passage is operated. Operability is improved by providing a check valve 11 on the most downstream side of the downcomer 4.