Offloading vacuum tank

1. A method for moving solid material, comprising:

pulling air and solid material through a tube and into a tank, wherein the tank has a vacuum pressure;

conveying material with an internal conveyor to a discharge end of the tank, wherein the internal conveyor is situated entirely within the tank at the vacuum pressure;

transferring material from the discharge end to a first end of an external conveyor, the external conveyor situated entirely outside the tank; and

moving material away from the tank with the external conveyor.

2. The method of claim 1 in which each of the steps occur simultaneously with each of the other steps.

3. The method of claim 1 in which the step of conveying material with an internal conveyor occurs after ceasing the step of pulling air and solid material through a tube and into the tank.

4. The method of claim 1 in which the step of transferring material from the discharge end to the external conveyor occurs after ceasing the step of pulling air and solid material through the tube and into the tank.

5. The method of claim 1 in which the internal conveyor is an auger.

6. The method of claim 1 in which the step of transferring material from the discharge end to the external conveyor comprises:

opening a ground-facing door at the discharge end, the door situated between the material within the tank and an end of the external conveyor.

7. The method of claim 1 in which the step of transferring material from the discharge end to the external conveyor comprises:

rotating an element in an airlock to provide metered release of material from the tank to the external conveyor.

8. The method of claim 1 further comprising:

releasing the material at a second end of the external conveyor.

9. The method of claim 1 wherein the external conveyor is an auger.

10. The method of claim 9 in which the internal conveyor is an auger.

11. The method of claim 1 in which:

the step of pulling air and solid material through the tube comprises:

placing an open end of the tube proximate a solid material to be removed;

actuating a blower in communication with the tube;

forcing the air through the tube and out of the tank through the blower; and

filtering the tank such that the solid material remains within the tank.

12. The method of claim 1 in which the tank comprises downwardly converging sidewalls and in which the internal conveyor is disposed between the downwardly converging sidewalls.

13. A method of handling spoils comprising:

operating a blower to pull air and spoils from an excavation site into a tank;

operating an internal conveyor to move spoils to a discharge end of the tank, wherein the entire internal conveyor is disposed within the tank at a vacuum pressure; and

operating an external conveyor to convey spoils away from the discharge end of the tank, wherein the entire external conveyor is disposed outside the tank.

14. The method of claim 13 further comprising:

maintaining a ground-facing door disposed at the discharge end of the tank and above the external conveyor in an open state.

15. The method of claim 14 in which the ground-facing door is maintained in an open state while the blower is operated.

16. The method of claim 13 further comprising;

removing air from the tank with the blower; and

cleaning the removed air.

17. The method of claim 13 further comprising:

placing an end of the external conveyor above a dump container;

such that spoils conveyed away from the discharge end of the tank are deposited in the dump container when they reach the end of the external conveyor.

18. The method of claim 13 further comprising:

with a microtrenching machine, removing spoils from a trench.

19. The method of claim 18 , further comprising:

placing an end of the external conveyor above the dump container such that spoils conveyed away from the discharge end of the tank are deposited in the dump container when they reach the end of the external conveyor.

20. The method of claim 19 in which the steps are performed simultaneously.