Apparatus for backwashing filter

Abstract

The reliability of backwashing valves constituted of first backwashing valves and second backwashing valves is ensured. A first backwashing valve (backwashing-gas rear valve) ( 7 ) that controls gas for backwashing and a second backwashing valve (backwashing-gas front valve) ( 6 ) that operates at slower speed than the first backwashing valve ( 7 ) are disposed, in a series including two or more thereof, at backwashing-gas introducing pipes individually provided for each of the filter blocks.

1 . An apparatus for backwashing filter in a dust removal device using porous material, having a plurality of filter blocks which are constituted of a plurality of filter elements accommodated in a pressure vessel and partitioning plates that partition or support these filter blocks, the pressure vessel being internally divided into a space for dust-containing gas, which includes a dust hopper, and a plurality of spaces for purified gas;
 in an apparatus for backwashing filter that periodically performs backwashing of the filter elements for each of the filter blocks, wherein a backwashing nozzle directed toward the filter elements is provided inside purified-gas lead-out pipes or inside spaces upstream thereof, each of which is connected to the plurality of spaces for the purified gas or a filter-element outlet,   a first backwashing valve that controls gas for backwashing and a second backwashing valve that operates at slower speed than the first backwashing valve are disposed, in a series including two or more thereof, at backwashing-gas introducing pipes individually provided for each of the filter blocks.   
     
     
         2 . An apparatus for backwashing filter in a dust removal device using porous material, having a plurality of filter blocks which are constituted of a plurality of filter elements accommodated in a pressure vessel and partitioning plates that partition or support these filter blocks, the pressure vessel being internally divided into a space for dust-containing gas, which includes a dust hopper, and a plurality of spaces for purified gas;
 in an apparatus for backwashing filter that periodically performs backwashing of the filter elements for each of the filter blocks, wherein a backwashing nozzle directed toward the filter elements is provided inside purified-gas lead-out pipes or inside spaces upstream thereof, each of which is connected to the plurality of spaces for the purified gas or a filter-element outlet,   a first backwashing valve and a second backwashing valve are disposed, in a series including two or more thereof, at backwashing-gas introducing pipes individually provided for each of the filter blocks, and gas for backwashing is controlled by the first backwashing valve alone.   
     
     
         3 . An integrated coal gasification combined cycle system equipped with the apparatus for backwashing filter according to  claim 1 . 
     
     
         4 . An integrated coal gasification combined cycle system equipped with the apparatus for backwashing filter according to  claim 2 .