Pulse detonation device for coal gasification

In a method of gasifying coal wherein a bed of coal within a gasifier is converted to fuel gases by partial combustion, the improvement comprising:

• providing at least one gasifier pulse detonation device which has a combustion chamber with an open discharge end;
• communicating the discharge end of the gasifier pulse detonation device to the bed of coal within the gasifier;
• injecting a discrete gaseous fuel mixture into the combustion chamber and igniting the fuel mixture to create a detonation wave which discharges from the discharge end, then repeating the injection and ignition of the gaseous fuel mixture at a selected frequency to produce high energy hot exhaust pulses;
• directing the pulses from the gasifier pulse detonation device into the bed of coal within the gasifier to enhance the conversion of coal into fuel gases by retarding slag glomeration;
• mounting a plurality of ceramic filtration candles in a filter chamber, each of the candles having a porous side wall and an interior passage, the interior passages being connected to an outlet manifold which leads out of the filter chamber;
• flowing the fuel gases into the filter chamber, through the side walls of the candles into the interior passages, through the outlet manifold and out of the filter chamber, filtering the fuel gases of particles as the fuel gases pass through the side walls of the candles;
• and wherein the method further comprises periodically cleaning the side walls of the candles of deposited particles by the following steps:
• providing at least one filter pulse detonation device which has a combustion chamber with an open discharge end;
• injecting a discrete gaseous fuel mixture into the combustion chamber of the filter pulse detonation device, and igniting the fuel mixture to create a detonation wave which discharges from the discharge end, then repeating the injection and ignition of the gaseous fuel mixture at a selected frequency to produce high energy hot exhaust pulses;
• and
• momentarily ceasing flow of fuel gases through the candles, and directing the pulses from the filter pulse detonation device into the outlet manifold and into the interior passages of the candles, dislodging deposited particles from the side walls.

A method of gasifying coal, comprising:

• introducing coal into a gasifier, creating a bed of coal;
• injecting air and steam into the gasifier and partially combusting the coal by heat within the gasifier to produce fuel gas;
• providing at least one gasifier pulse detonation device which has a combustion chamber with an open discharge end;
• communicating the discharge end of the gasifier pulse detonation device to the bed of coal within the gasifier;
• injecting substantially pure oxygen and a discrete gaseous fuel mixture into the combustion chamber, and igniting the fuel mixture to create a detonation wave which discharges from the discharge end at a supersonic speed, then repeating the injection and ignition of the gaseous fuel mixture at a selected frequency to produce high energy hot exhaust pulses;
• and
• directing the pulses from the gasifier pulse detonation device into the bed of coal within the gassifier to enhance movement of coal in the bed to improve the conversion of coal into gases.