Powder fuel feed apparatus, gasifier unit, and integrated gasification combined cycle and control method of powder fuel feed apparatus

A powder fuel feed apparatus comprising:

• a powder transport pipe;
• a mixing chamber;
• and
• an additional inert gas feed section,
• wherein the powder transport pipe is configured to transport a mixed gas containing moisture and a gas in which powder fuel and an associated inert gas transported with the powder fuel are mixed,
• wherein the mixing chamber is configured to be connected to and arranged in the middle of the powder transport pipe,
• wherein, when a flow velocity of the mixed gas is less than a predetermined threshold, the additional inert gas feed section is configured to additionally supply an additional inert gas to the mixing chamber,
• wherein the additional inert gas feed section is configured to continuously supply a predetermined flow rate of the additional inert gas to the mixing chamber,
• wherein the predetermined flow rate of the additional inert gas is a flow rate that suppresses occurrence of a reverse flow of the mixed gas from the mixing chamber to the additional inert gas feed section,
• wherein the mixing chamber has a plurality of sintered metal filters each made of cylindrical porous material having a predetermined thickness, and
• an annular intermediate ring connected and fixed to an outer circumference portion of each of the plurality of sintered metal filters, and
• wherein a central axis of the plurality of sintered metal filters and a central axis of the annular intermediate ring are provided along a central axis direction of the mixing chamber.