System for controlling circulatory amount of particles in circulating fluidized bed furnace

A system for controlling an amount of particles to be circulated in a circulating fluidized bed gasification furnace and a fluidized bed combustion furnace wherein the particles are introduced together with char produced through gasification of raw material are introduced into a fluidized bed combustion furnace to heat the particles through fluidized combustion of the char,

• burnt gas taken out from the fluidized bed combustion furnace by exhaust gas induction means being introduced into a separator where the gas is separated into exhaust gas and the particles,
• the separated hot particles and the raw material being supplied to a fluidized bed gasification furnace into which a gasification agent is introduced, the raw material being gasified by a fluidized bed in the gasification furnace, resultant gas generated through gasification of the raw material being taken out from the fluidized bed gasification furnace by a resultant gas induction means, the particles and char produced through gasification of the raw material being circulated to the fluidized bed combustion furnace,
• said system comprising
• said fluidized bed gasification furnace partitioned by partition means into first and second chambers in communication with each other at a lower communicating portion in the fluidized bed, the hot particles from the separator and raw material being introduced into the first chamber, said second chamber for supplying char and particles introduced from said first chamber via the lower communicating portion below the partition means to the fluidized bed combustion furnace through overflow,
• a first pressure sensor for detecting pressure in the first chamber,
• a second pressure sensor for detecting pressure in the second chamber,
• a first pressure controller for controlling the resultant gas induction means so as to keep the pressure in the first chamber to preset pressure and
• a second pressure controller for controlling the exhaust gas induction means so as to make difference in pressure between the first and second chambers to preset differential pressure, whereby the fluidized bed in the first chamber is adjusted in height to control an amount of particles to be circulated.