Exhaust gas desulfurizing method and system therefor

A method of desulfurizing flue gas in which desulfurization is effected by bringing absorbent slurry containing limestone into contact with flue gas, comprising the steps of:

• classifying absorbent slurry extracted from a desulfurization absorber, returning a fine-side fluid to said desulphurization absorber, and sending a coarse-side fluid to a solid-liquid separator;
• supplying supplied limestone to a limestone grinder to yield limestone slurry;
• classifying said limestone slurry, sending a small-particle fluid component thereof to said desulfurization absorber, and sending a large-particle fluid component thereof to a limestone fine grinder;
• and
• finely grinding limestone contained in said large-particle fluid component by said limestone fine grinder and sending the finely ground limestone to said desulfurization absorber.

A system for desulfurizing flue gas in which desulfurization is effected by bringing absorbent slurry into contact with flue gas, comprising:

• a desulfurization absorber adapted to desulfurize flue gas by circulation of absorbent slurry;
• an absorbent slurry classifier adapted to classify absorbent slurry extracted from said desulfurization absorber and to send a fine-side fluid to said desulfurization absorber;
• a solid-liquid separator adapted to separate a coarse-side fluid separated by said absorbent slurry classifier into a gypsum component and a filtrate component;
• a solid-liquid mixer adapted to mix supplied limestone powder and a portion of the filtrate to yield limestone slurry;
• a limestone slurry classifier adapted to classify said limestone slurry into a small-particle fluid component to be sent to said desulfurization absorber and a large-particle fluid component to be subjected to fine grinding;
• and
• a limestone fine grinder adapted to finely grind said large-particle fluid component and to send the finely ground component to said desulfurization absorber.

A system for desulfurizing flue gas in which desulfurization is effected by bringing absorbent slurry into contact with flue gas, comprising:

• a desulfurization absorber adapted to desulfurize flue gas by circulation of absorbent slurry;
• an absorbent slurry classifier adapted to classify absorbent slurry extracted from said desulfurization absorber and to send a fine-side fluid to said desulfurization absorber;
• a solid-liquid separator adapted to separate a coarse-side fluid separated by said absorbent slurry classifier into a gypsum component and a filtrate component;
• a limestone grinder adapted to grind supplied limestone to yield limestone slurry;
• a limestone slurry classifier adapted to classify said limestone slurry into a small-particle fluid component to be sent to said desulfurization absorber and a large-particle fluid component to be subjected to fine grinding;
• and
• a limestone fine grinder adapted to finely grind said large-particle fluid component and to send the finely ground component to said desulfurization absorber.

A method for desulfurizing flue gas, comprising:

• classifying absorbent slurry extracted from a desulfurization absorber into a first fluid to be returned to the desulfurization absorber and a second fluid;
• separating the second fluid to obtain a filtrate;
• mixing limestone powder and the filtrate to obtain limestone slurry;
• classifying the limestone slurry into a relatively smaller particle fluid to be sent to the desulfurization absorber and a relatively larger particle fluid;
• grinding limestone contained in the relatively larger particle fluid to obtain ground limestone;
• and
• sending the ground limestone to the desulfurization absorber.

A method of desulfurizing flue gas, comprising:

• classifying absorbent slurry extracted from a desulfurization absorber into a first fluid to be returned to the desulfurization absorber and a second fluid;
• grinding limestone with a first grinder to obtain limestone slurry;
• classifying the limestone slurry into a relatively smaller particle fluid to be sent to the desulfurization absorber and a relatively larger particle fluid;
• grinding limestone contained in the relatively larger particle fluid with a second grinder to obtain ground limestone;
• and
• sending the ground limestone to the desulfurization absorber.