Method for reduction of slagging and fouling of the waterwalls and of the firebox and superheater and reheater of steam boilers with coal combustion

A method of reducing slagging and fouling in a furnace of a coal-fired steam boiler, the method comprising:

• a. atomizing a water-based coolant, wherein the water-based coolant is a sorbent water slurry, and further wherein the slurry includes water and a sorbent material, the sorbent material being magnesium-based;
• b. injecting the water-based coolant through at least one of one or more ports into an upper section of a firebox in the furnace;
• and
• c. mixing the water-based coolant with hot flue gas from the furnace, the hot flue gas having a higher temperature than the water-based coolant,
• wherein the mixing reduces the higher temperature to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. a flue gas duct coupled to a flue gas filter, and further coupled to one or more ports in an upper section of a firebox in the furnace, wherein the flue gas duct as configured to divert cooled flue gas, and further wherein the flue gas filter is configured to clean the cooled flue gas and receive flue gas from an air preheater, the air preheater receiving the flue gas from the furnace;
• b. at least one fan configured to propel the cooled flue gas through the flue gas duct;
• and
• c. at least one recirculation jet to inject the cooled flue gas into one or more of the ports in the upper section of the firebox,
• wherein the cooled flue gas is mixed with hot flue gas from the furnace, and the cooled flue gas reduces the temperature of the hot flue gas from the furnace to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. at least one atomizer for atomizing a water-based coolant, wherein the water-based coolant is a sorbent water slurry, and further wherein the slurry includes water and a sorbent material, the sorbent material being magnesium-based;
• and
• b. at least one injection jet for injecting the atomized water-based coolant through one or more ports into an upper section of a firebox in the furnace to mix with hot flue gas from the furnace, the hot flue gas having a higher temperature than the water-based coolant,
• wherein the mixing reduces the higher temperature to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. means for diverting cooled flue gas from an output of a flue gas filter, wherein the flue gas filter is configured to clean the cooled flue gas by removing fly ash particulates and receive flue gas from an air preheater, the air preheater receiving the flue gas from the furnace;
• b. means for recirculating the cooled flue gas to one or more ports in an upper section of a firebox in the furnace;
• c. means for injecting the cooled flue gas into one or more of the ports in the upper section of the firebox;
• and
• d. means for mixing the cooled flue gas with hot flue gas from the furnace, the hot flue gas having a higher temperature than the cooled flue gas,
• wherein the mixing reduces the higher temperature to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. means for atomizing a water-based coolant, wherein the water-based coolant is a sorbent water slurry, and further wherein the slurry includes water and a sorbent material, the sorbent material being magnesium-based;
• b. means for injecting the water-based coolant through one or more ports into an upper section of a firebox in the furnace;
• and
• c. means for mixing the water-based coolant with hot flue gas from the furnace, the hot flue gas having a higher temperature than the water-based coolant,
• wherein the mixing reduces the higher temperature to below a threshold temperature.

A method of reducing slagging and fouling in a furnace of a coal-fired steam boiler, the method comprising:

• a. diverting cooled flue gas from an output of a flue gas filter, wherein the flue gas filter is configured to clean the cooled flue gas by removing fly ash particulates;
• b. recirculating the cooled flue gas to one or more ports in an upper section of a firebox in the furnace;
• c. injecting the cooled flue gas into at least one of the one or more of the ports into the upper section of the firebox;
• d. atomizing a water-based coolant;
• e. injecting the water-based coolant through at least one of the one or more ports into the upper section of the firebox in the furnace;
• and
• f. mixing the cooled flue gas and the water-based coolant with hot flue gas from the furnace, the hot flue gas having a higher temperature than the cooled flue gas and the water-based coolant,
• wherein the mixing reduces the higher temperature to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. a flue gas duct coupled to a flue gas filter, and further coupled to one or more ports in an upper section of a firebox in the furnace, wherein the flue gas duct is configured to divert cooled flue gas, and further wherein the flue gas filter is configured to clean the cooled flue gas;
• b. at least one fan configured to propel the cooled flue gas through the flue gas duct;
• c. at least one recirculation jet to inject the cooled flue gas into at least one of the one or more of the ports into the upper section of the firebox;
• d. at least one atomizer for atomizing a water-based coolant;
• and
• e. at least one injection jet for injecting the water-based coolant into at least one of the one or more ports into the upper section of the firebox in the furnace,
• wherein the cooled flue gas and the water-based coolant mix with hot flue gas from the furnace having a higher temperature than the cooled flue gas and the water-based coolant mix, and the cooled flue gas and the water-based coolant reduce the temperature of the hot flue gas to below a threshold temperature.

A system for reducing slagging and fouling in a furnace of a coal-fired steam boiler, the system comprising:

• a. means for diverting cooled flue gas from an output of a flue gas filter, wherein the flue gas filter is configured to clean the cooled flue gas by removing fly ash particulates;
• b. means for recirculating the cooled flue gas to one or more ports in an upper section of a firebox in the furnace;
• c. means for injecting the cooled flue gas into at least one or the one or more of the ports into the upper section of the firebox;
• d. means for atomizing a water-based coolant;
• e. means for injecting the water-based coolant through at least one of the one or more ports into the upper section of the firebox in the furnace;
• and
• f. means for mixing the cooled flue gas and the water-based coolant with hot flue gas from the furnace, the hot flue gas having a higher temperature than the cooled flue gas and the water-based coolant,
• wherein the mixing reduces the higher temperature to below a threshold temperature.