System, method and apparatus for solid fuel ignition

1. An ignition system, comprising:

a pulverized fuel pipe receiving a mixture of pulverized fuel and primary air for injection into a combustion chamber for combustion;

an igniter received within the pulverized fuel pipe for igniting the mixture; and

a plurality of angled projections formed on an inner wall of the pulverized fuel pipe, the angled projections being configured to divert at least a portion of the mixture into a flame of the igniter;

wherein the igniter is axially movable within the pulverized fuel pipe; and

wherein the plurality of angled projections are arranged in at least two rows, wherein the projections in one of the rows are radially offset from the projections in another of the rows.

2. The ignition system of claim 1 , further comprising:

an annular gap defined between an outer wall of the igniter and an inner wall of the pulverized fuel pipe for receiving the mixture prior to ignition.

3. The ignition system of claim 2 , further comprising:

a moving mechanism coupled to the igniter for axially moving the igniter within the pulverized fuel pipe.

4. The ignition system of claim 3 , wherein:

the ignition system forms a portion of a round burner.

5. The ignition system of claim 4 , wherein:

the igniter is movable away from an outlet end of the pulverized fuel pipe to increase the ignition residence time; and

the igniter is movable towards the outlet end of the pulverized fuel pipe to decrease the ignition residence time.

6. The ignition system of claim 2 , further comprising:

a core air pipe received within the pulverized fuel pipe;

wherein the igniter is received within the core air pipe; and

wherein the core air pipe is axially movable within the pulverized fuel pipe for maintaining the annular gap when the igniter is moved axially rearward.

7. The ignition system of claim 1 wherein:

the igniter is a plasma igniter.

8. The ignition system of claim 1 further comprising:

an inlet in the igniter for receiving circumferential air into an interior of the igniter, the circumferential air being controllable to selectively increase or decrease pulverized fuel ignition.

9. The ignition system of claim 1 , wherein:

the projections are offset by greater than about 10 degrees.

10. An ignition system, comprising:

a pulverized fuel pipe receiving a mixture of pulverized fuel and primary air for injection into a combustion chamber for combustion;

an igniter received within the pulverized fuel pipe for igniting the mixture; and

a pulverized fuel concentrator positioned within the pulverized fuel pipe adjacent an outlet end of the pulverized fuel pipe and defining an annular passageway between the pulverized fuel concentrator and the pulverized fuel pipe;

wherein the igniter is axially movable within the pulverized fuel pipe; and

wherein when the igniter is moved to a forward position adjacent to the pulverized fuel concentrator, the pulverized fuel concentrator, the igniter and the pulverized fuel pipe form a generally continuous annular gap extending from the igniter to the outlet.

11. A method for igniting a solid fuel, comprising the steps of:

providing a mixture of pulverized fuel and primary air to a pulverized fuel pipe having an outlet end;

igniting the mixture with an igniter received axially within the pulverized fuel pipe; and

varying an ignition residence time of the mixture by axially moving the igniter within the pulverized fuel pipe to vary a distance of a forward end of the igniter with respect to the outlet end of the pulverized fuel pipe;

wherein the pulverized fuel pipe includes a pulverized fuel concentrator positioned within the pulverized fuel pipe adjacent the outlet end and which defines an annular passageway between the pulverized fuel concentrator and the pulverized fuel pipe; and

wherein the method further includes the step of moving the igniter to a forward position adjacent to the pulverized fuel concentrator to form a generally continuous annular gap extending from the igniter to the outlet.

12. The method according to claim 11 , wherein:

an outer wall of the igniter and an inner wall of the pulverized fuel pipe define an annular gap for receiving the mixture prior to ignition.

13. The method according to claim 11 , wherein:

the step of varying the ignition residence time includes moving the igniter away from the outlet end of the pulverized fuel pipe to increase the ignition residence time and moving the igniter towards the outlet end of the pulverized fuel pipe to decrease the ignition residence time.

14. The method according to claim 11 , wherein:

the igniter is a plasma igniter.

15. The method according to claim 11 , further comprising the step of:

deflecting the mixture into a flame generated by the igniter with a plurality of angled projections on an inner wall of the pulverized fuel pipe.