Cooled gasifier vessel throat plug with instrumentation cavity

1. A throat plug for a gasifier vessel, the throat plug comprising:

a first cavity, the first cavity being configured to hold at least one device in the first cavity, the first cavity being accessible through a hole formed in the throat plug;

a second cavity, the second cavity being nested within the first cavity, the second cavity being configured to hold a fuel injector; and

a third cavity that surrounds the first cavity along an outer radial surface of the first cavity and along an inner radial surface of the first cavity opposite the outer radial surface, the third cavity configured to circulate a coolant through the third cavity to cool a temperature of the first cavity.

2. The throat plug of claim 1 , further comprising:

at least one tube that extends through an entire length of the first cavity and is sealed off from an inside of the first cavity.

3. The throat plug of claim 2 , the at least one tube having an opening at each end of the throat plug.

4. The throat plug of claim 1 , further comprising:

a first opening in the throat plug to introduce the coolant into the third cavity; and

a second opening in the throat plug to facilitate the exit of the coolant from the third cavity.

5. The throat plug of claim 1 , further comprising:

a flange located at an outside end of the first cavity, the second cavity, and the third cavity; and

a gasket configured to be located between the flange of the throat plug and a flange of the fuel injector.

6. The throat plug of claim 1 , the throat plug being cylindrical in shape, the at least one first cavity and the at least one second cavity being cylindrical in shape.

7. The throat plug of claim 6 , the at least one first cavity encircling the at least one second cavity.

8. The throat plug of claim 1 , wherein the throat plug comprises one of a cobalt- and a nickel-based alloy.