Laser system slag removal

• US 20030222062A1
• Filed: 06/01/2002
• Published: 12/04/2003
• Est. Priority Date: 06/01/2002
• Status: Active Grant

• Current Assignee: First Call Explosive Solutions, Inc.
• Original Assignee: First Call Explosive Solutions, Inc.
• Inventors: Brown, Robert K., Cammarata, Frank A. Jr.
• Granted Patent: US 6,710,285 B2
• Time in Patent Office: Days
• US Class Current: 219/121.68
• CPC Class Codes: B08B 7/0042 by laser
• CPC Class Codes: B08B 9/023 Cleaning the external surface B08B9/021 takes precedence
• CPC Class Codes: B23K 26/0624 using ultrashort pulses, i.e. pulses of 1ns or less
• CPC Class Codes: F28G 13/00 Appliances or processes not covered by groups F28G1/00 - F28G11/00; Combinations of appliances or processes covered by groups F28G1/00 - F28G11/00

Abstract

A system for removing slag from a boiler includes a laser, a targeting system, and a computer system for controlling the operation of the laser and targeting system. Preferably, the laser includes chemicals contained in a mixing pre-chamber. A pump connects to the pre-chamber, and an iodine laser diode connects to the pump. The laser unit also has a power source, cooling system, and a raw beam laser. The targeting system is driven by targeting software and includes an optical targeting system. Preferably, the system also includes a mobile trailer with a computer control room, a main laser operating unit, and a portable optical targeting system connected to the laser unit. Fiber optic cable connects the targeting system and the laser. The online deslagging method includes transporting and setting-up the system, relaying set-up information, feeding targeting information, activating and operating the laser to remove slag from within the boiler.

Claims

1. A boiler deslagging system comprising:

a laser for removing slag from a boiler;

a targeting system operationally connected to the laser; and

a computer system for controlling the operation of the laser and targeting system.

2. The deslagging system of claim 1 wherein the laser is comprised of a chemical laser having at least one of:

hydrogen peroxide, sodium hydroxide, potassium hydroxide, and chlorine.

3. The deslagging system of claim 1 wherein laser includes a mixing pre-chamber, a pump connected to the pre-chamber, and an iodine laser diode connected to the pump.

4. The deslagging system of claim 1 wherein the targeting system is driven by a laser targeting software and wherein the targeting system includes an optical targeting system.

5. A slag removal system for a boiler comprising:

a mobile trailer including a control room;

a main laser operating unit connected with the trailer;

a portable optical targeting system operationally connected to the laser unit;

a computer in the control room for operating the laser unit and the targeting system;

fiber optic cable connecting the targeting system and the laser unit; and

wherein the laser unit includes a power source, cooling system, and a raw beam laser.

6. A method of deslagging a boiler while the boiler is still in operation comprising the steps of:

transporting a deslagging system;

setting-up the deslagging system including the steps of;

booting-up a computer in a control room,

warming up a laser to include mixing chemicals to power a laser,

laying-out fiber optics needed to reach the boiler, and

connecting the fiber optics to a gun targeting system and the laser;

ensuring significant safeguards are in place to prevent inadvertant triggering of the laser, harm to an operator and damage to the fiber optics;

setting-up the gun;

relaying the set-up information to the control room;

feeding targeting information from the control room;

activating the system; and

operating the system to remove slag from internal structures within the boiler.

7. The method of claim 6, further comprising the steps of:

forming a crew consisting of a operator, a supervisor, and control room personnel; and

training the crew to be interchangeable with each other and intimately knowledgeable of the system they are operating.

8. The method of claim 6, further comprising the steps of:

training the crew to have overlapping job duties; and

removing the slag starting from the bottom of the boiler.

9. The method of claim 6, further comprising the steps of:

working the laser beam up the tubes within the boiler starting from the ground level of the boiler.

10. The method of claim 6, further comprising the steps of:

cleaning a boiler to produce a by-product of just ash; and

reducing the amount of dust created up.

11. The method of claim 6, further comprising the step of removing platenization from tubes for non-destructive inspection by power plant personal.

12. A system for extending the typical maintenance schedule of a power plant comprising:

an on-line boiler including walls, an observation portal and a boiler tube having surfaces;

a laser main unit having a laser which does not pit and groove the surfaces of the tube and reduces the mess normally associated with tube cleaning;

a fiber optic cable connected to the laser main unit;

a gun connected to the cable for targeting and safely removing slag from the boiler tube through the observation portal outside the walls of a boiler; and

a measuring system to help determine the distance the slag is from the portal.

13. The system of claim 12, further comprising a computer control system for a deslagging laser comprising:

a rugged design for handling environments in a power plant;

a storage device containing individual boiler parameter data.

14. The system of claim 13, wherein the computer control systems is in located a trailer

15. The system of claim 14, further comprising a wireless controller for targeting and imaging inside the boiler while online.

16. The system of claim 14, wherein the storage device includes reference points from the observation portal to the tube and from the portal.

17. The system of claim 16, wherein the reference points are accessed in at least one the following ways:

from on the tubes, from outside the boiler, and as electronic files to provide a fixed spot to start and reference from, and wherein the points are updated regularly to record any changes to the inside of the boiler.

18. The system of claim 16, wherein the computer system includes 800+ GHz processor and 500+ MB of ram, a high-capacity hard drive, and a system to cool the computers.

19. The system of claim 16, wherein the laser has optics, a front and rear and the front of the laser is cooled by an air curtain between the observation portal and the laser, said air curtain is comprised of at least one of:

cold air and a nitrogen gas.

20. The system of claim 19, wherein the laser further comprises a sapphire crystal, an optical system, and a power generator for appropriately powering the laser to affect the slag material and not the boiler tube substrate;

wherein the laser heats the slag in nanoseconds to the point in which it turns the slag into plasma and subsequently disintegrates it and while bouncing off the tube surface;

wherein the laser is properly calibrated to take into account the wavelength of light inside the boiler and the light the fireball gives off;

wherein the laser is calibrated to take into account the airflow inside the boiler and the fact that airflow draws the ash up and through the boiler; and

wherein the laser is calibrated according to the thickness of to the ash build up on the tubes.