Provided are a gasification furnace operating method, a gasification furnace, a two-stage gasification apparatus, a gasification method for an organic raw material, and a two-stage gasification method for organic waste that make it possible to stably operate a gasification furnace over a long period of time. The present invention provides a gasification furnace operating method including, in a gasification furnace into which an organic raw material is introduced and that produces gas and slag, directly or indirectly introducing an alkali metal-containing compound into the gasification furnace to reduce the viscosity of the slag.

Provided are a gasification furnace operating method, a gasification furnace, a two-stage gasification apparatus, a gasification method for an organic raw material, and a two-stage gasification method for organic waste that make it possible to stably operate a gasification furnace over a long period of time. The present invention provides a gasification furnace operating method including, in a gasification furnace into which an organic raw material is introduced and that produces gas and slag, directly or indirectly introducing an alkali metal-containing compound into the gasification furnace to reduce the viscosity of the slag.

A blocking prevention device for a gasification melting system combusts and melts an object to be treated into a slag in a melting furnace after the object to be treated is converted into pyrolysis gas in a gasification furnace, the blocking prevention device including: a slag adhesion prevention device having a slag adhesion prevention capability for preventing adhesion of the slag at an opening part that may be blocked due to the adhesion of the slag; an imaging device that images the opening part; and a control device including a calculation unit that calculates a change rate of an opening area of the opening part using a plurality of images with different capturing times or a video, captured by the imaging device, and a prevention device control unit that changes the slag adhesion prevention capabilities of a plurality of the slag adhesion prevention devices in accordance with the change rate.

A blocking prevention device for a gasification melting system combusts and melts an object to be treated into a slag in a melting furnace after the object to be treated is converted into pyrolysis gas in a gasification furnace, the blocking prevention device including: a slag adhesion prevention device having a slag adhesion prevention capability for preventing adhesion of the slag at an opening part that may be blocked due to the adhesion of the slag; an imaging device that images the opening part; and a control device including a calculation unit that calculates a change rate of an opening area of the opening part using a plurality of images with different capturing times or a video, captured by the imaging device, and a prevention device control unit that changes the slag adhesion prevention capabilities of a plurality of the slag adhesion prevention devices in accordance with the change rate.

A method and apparatus for cleaning a black liquor recovery boiler, where a furnace floor of the boiler is washed by mixing wash water in a wash water pool formed on the floor by at least one mixing device in the wash water pool, and by jetting wash water towards the floor by at least one pressure washer installed into the furnace through an opening in the furnace wall.

A method and apparatus for cleaning a black liquor recovery boiler, where a furnace floor of the boiler is washed by mixing wash water in a wash water pool formed on the floor by at least one mixing device in the wash water pool, and by jetting wash water towards the floor by at least one pressure washer installed into the furnace through an opening in the furnace wall.

The present disclosure concerns a pyrolysis residue-discharge system fluid-tightly connectable to a pyrolysis reactor delimiting a fuel-containing cavity and having a discharge opening extending therethrough, the pyrolysis residue-discharge system comprising a residue discharge duct defining a residue discharge passageway having an inlet port and an outlet port; and a reactor-connecting end portion having a through opening, the reactor-connecting end portion being fluid-tightly connectable to the pyrolysis reactor to fluidly connect the through opening of the reactor-connecting end portion with the discharge opening of the pyrolysis reactor, the reactor-connecting end portion being fluid-tightly connectable to the residue discharge duct at the inlet port thereof to provide a fluid communication between the fuel-containing cavity of the pyrolysis reactor and the residue discharge passageway via the discharge opening. It also concerns a corresponding pyrolysis reactor assembly and a pyrolysis residue discharge method.

A slag discharge system includes a slag bath at a bottom portion of a gasifier; a slag cooling water circulation line that discharges a mixture of slag and a slag cooling water from the slag bath; a coarse slag separator device that separates coarse slag contained in the slag cooling water; a fine slag separator device connected to the coarse slag separator device downstream side, the fine slag separator device separating fine slag; and a circulator pump connected to the fine slag separator device downstream side, the circulator pump creating a water flow in the slag cooling water circulation line; wherein the fine slag separator device includes a branch section where the slag cooling water circulation line branches into a plurality of branch lines and again joins together as one line, a fine slag filter portion, and a shutoff valve and disposed in each of the plurality of branch lines.

A slag discharge system includes a slag bath at a bottom portion of a gasifier; a slag cooling water circulation line that discharges a mixture of slag and a slag cooling water from the slag bath; a coarse slag separator device that separates coarse slag contained in the slag cooling water; a fine slag separator device connected to the coarse slag separator device downstream side, the fine slag separator device separating fine slag; and a circulator pump connected to the fine slag separator device downstream side, the circulator pump creating a water flow in the slag cooling water circulation line; wherein the fine slag separator device includes a branch section where the slag cooling water circulation line branches into a plurality of branch lines and again joins together as one line, a fine slag filter portion, and a shutoff valve and disposed in each of the plurality of branch lines.

A method and apparatus for cleaning a black liquor recovery boiler, where a furnace floor of the boiler is washed by mixing wash water in a wash water pool formed on the floor by at least one mixing device in the wash water pool, and by jetting wash water towards the floor by at least one pressure washer installed into the furnace through an opening in the furnace wall.