RAPPER MECHANICAL ARRANGEMENT OF A RADIANT SYNGAS COOLER

Abstract

An embodiment in accordance with the present invention provides a device and method for removing ash from an interior surface of a radiant synthesis gas cooler. The device for removing ash includes a rapper actuator, a striker pin coupled to the rapper actuator including a proximal end and a distal end, and a striker target assembly disposed such that a proximal surface of the striker target assembly is in contact with the distal end of the striker pin and a distal surface is in contact with the surface of the radiant synthesis gas cooler.

Description

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates generally to the field of coal gasification and, to a Radiant Synthesis Gas (syngas) Cooler (RSC) for an Integrated Gasification Combined Cycle (IGCC) power plant. More particularly, the present invention relates to a rapper to remove ash from pressure parts within the RSGC.

The Radiant Synthesis Gas Cooler (RSC) is a component of an Integrated Gasification Combined Cycle (IGCC) power plant. Hot gas and molten ash from the gasification process enter the top of a vertical pressure vessel. Inside the vertical pressure vessel are pressure parts that cool the gas and generate steam for the steam turbine cycle. Ash attaches to the pressure parts in a process called ash deposition. Ash deposition reduces the heat transfer through the pressure parts and steam flow to the turbine. Therefore, in order to maintain power output for the plant it is desirable for at least some of the ash to be removed from the pressure parts.

One such method for removing the ash from the pressure parts is to use sootblowers that use nitrogen as a cleaning fluid. However, many of these sootblowers have been removed from service and their effectiveness to clean is not known. Accordingly, it is desirable to provide a method and apparatus to remove the ash from the pressure parts of the RSC.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect a device is provided that in some embodiments removes ash from an interior surface of a radiant synthesis gas cooler in order to increase steam flow and therefore power output in a power plant.

In accordance with one aspect of the present invention, a device for removing ash from a surface of a radiant synthesis gas cooler includes a rapper actuator, a striker pin coupled to the rapper actuator including a proximal end and a distal end, and a striker target assembly disposed such that a proximal surface of the striker target assembly is in contact with the distal end of the striker pin and a distal surface is in contact with the surface of the radiant synthesis gas cooler. The striker target assembly can also include a striker target plate. The striker target plate can include a cylindrical bar or can include two striker target plates.

In accordance with another aspect of the present invention, the striker target assembly includes a wear plate mounted on the interior surface of the radiant synthesis gas cooler such that the wear plate is in contact with the distal end of the striker target plate. Additionally, the rapper actuator can take the form of a pneumatic rapper actuator or an electromagnetic actuator. The striker target assembly can be movably disposed within the radiant synthesis gas cooler.

In accordance with another aspect of the present invention, a striker target assembly for removing ash from an interior surface of a radiant synthesis gas cooler includes a tube cage assembly defining a slot, a striker target plate including a distal surface and a proximal surface, wherein the striker target plate extends through the slot, and a wear plate mounted on the interior surface of the radiant synthesis gas cooler such that the wear plate is in contact with the distal surface of the striker target plate. The striker target assembly can be movably disposed within the radiant synthesis gas cooler, and the striker target assembly can also include a striker pin in contact with the proximal surface of the striker target assembly.

In accordance with yet another aspect of the present invention the striker target plate, the striker pin, and the wear plate are all in alignment. Also, the striker target plate can include two striker target plates. Additionally, the tube cage assembly can include a membrane surrounding an outside surface of the tube cage assembly and the membrane defines an opening through which the striker target plate extends. Further, there can be a gap between the striker target plate and the membrane.

In accordance with still another aspect of the present invention, a method of removing ash from a radiant synthesis gas cooler includes mounting a wear plate on an interior surface of the radiant synthesis gas cooler from which the ash is to be removed and contacting a surface of the wear plate with a distal surface of a striker target plate that extends through a tube cage assembly of the radiant synthesis gas cooler. The method can also include contacting a proximal surface of the striker target plate with a striker pin and inducing a vibration in the interior surface, from which the ash is to be removed, by transmitting a rapping energy through the striker pin to the striker target plate and the wear plate.

In accordance with another aspect of the present invention, the method further includes aligning the wear plate, the striker target plate, and the striker pin. The method can also include producing a rapping energy using a rapper actuator and mounting the striker target plate movably within the radiant synthesis gas cooler. Additionally, the method can include a striker target plate including two striker target plates.

There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view illustrating a rapper in accordance with an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides an apparatus for removing ash from pressure parts of a Radiant Synthesis Gas Cooler (RSC). The embodiments in accordance with the present invention may include a rapper actuator, a striker pin, a striker target, and wear plates.

FIG. 1 is a perspective view illustrating a rapper mechanical arrangement 10, according to one embodiment of the invention. The components are a rapper actuator 12, a striker pin 14, and a striker target assembly 16. The rapper actuator 12 can be pneumatic or electromagnetic. The striker pin 14 is spring loaded to assure that the striker pin 14 is in constant contact with the striker target assembly 16. The striker target assembly 16 is a composite assembly of parts described herein.

The rapper actuator 12 attaches to a flange 18 that is mounted on an outside surface of a wall 20 of a pressure vessel 22. The pressure vessel 22 is operated at pressures above atmospheric pressure and the environment inside the pressure vessel is in general corrosive. There are seals and inert gas purge to allow the penetration of the striker pin 14 through the pressure vessel wall 20 and without leakage of syngas to the atmosphere. Inside the pressure vessel is a tube and membrane construction pressure part assembly, sometimes called a tube cage assembly 24 that is typically round, but can be multiple sided. The tube cage assembly 24 is completely seal welded to contain the syngas. There is a space between the pressure vessel wall 20 and the tube cage assembly 24 called an annulus 26. The annulus 26 is continually purged with an inert gas to assure syngas does not remain in the annulus 26 and cause corrosion of tubes 28 forming the tube cage assembly 24 or the wall 20 of the pressure vessel 22.

On the inside of the tube cage assembly 24 are other pressure part assemblies 30 that absorb heat to produce steam. The pressure part assemblies 30 are sometimes called platens, division walls or wing walls. These internal pressure part assemblies 30 have ash depositing on the surface that reduce heat transfer and steam production. To maintain the required or expected steam production, the internal pressure part assemblies 30 need to be cleaned. Rapping energy induces a vibration in the pressure part assemblies 30 that induces shedding of the ash deposits. The highest rapping energy is transmitted to the internal pressure part assemblies 30 when there is direct contact between the rapper actuator 12 and the internal pressure part assemblies 30 and when the striker pin 14 and striker target assembly 16 are free to move.

One embodiment involves the striker target assembly 16, which includes at least one striker target plate 32. If two striker target plates 32 are used, they are located on opposite sides of a tube. There are slots 34 in the tube cage assembly 24 so that the striker target plate 32 can pass from the annulus 26 to the internal pressure part assemblies 30. The slots 34 are created by leaving a portion of a membrane 40 surrounding the tube cage assembly 24 off the assembly. The striker target plate 32 is sized to provide small gaps around the plate periphery, which minimize the amount of inert purge gas leakage from the annulus and allows for free movement of the target. The close fit between the striker target plate 32 and the tube cage assembly 24 maintains alignment between the striker pin 14 and the striker target assembly 16.

The internal pressure part assembly 30, the tube cage assembly 24, and the pressure vessel 22 operate at different temperatures. The thermal expansion of each component is different. Additionally, the internal pressure part assembly 30 can bow due to differential expansions. The internal pressure part assembly 30 must be oriented inline with the striker pin 14 and the striker target assembly 16. The striker target assembly 16 must also be in alignment with the internal pressure part assembly 30. The alignment is provided with tubes 36 from the pressure part assembly 30 which are bent around the striker target assembly 16. Attached to the tubes 36 are wear plates 38 that protect the tubes 36 and provide the alignment of the striker target assembly 16 and the internal pressure part assembly 30.

Alignment of the striker target assembly 16 to the internal pressure parts assembly 30 is provided while allowing free movement between the internal pressure part assembly 30, tube cage assembly 24, and the striker target assembly 16. Additionally, free movement of the striker target assembly 16 within the tube cage assembly 24 is provided, which maximizes the transmitted energy to the internal pressure part assembly 30. The gap between the annulus 26 and an internal side of the tube cage assembly 24 is minimized, which, in turn, minimizes the amount of inert gas leakage.

The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

1. A device for removing ash from a surface of a radiant synthesis gas cooler comprising:

a rapper actuator;

a striker pin coupled to the rapper actuator including a proximal end and a distal end; and

a striker target assembly disposed such that a proximal surface of the striker target assembly is in contact with the distal end of the striker pin and a distal surface is in contact with the surface of the radiant synthesis gas cooler.

2. The device of claim 1, wherein the striker target assembly comprises a striker target plate.

3. The device of claim 2, wherein the striker target plate comprises a cylindrical bar.

4. The device of claim 2, wherein the striker target plate comprises two striker target plates.

5. The device of claim 2, wherein the striker target assembly comprises a wear plate mounted on the interior surface of the radiant synthesis gas cooler such that the wear plate is in contact with the distal end of the striker target plate.

6. The device of claim 1, wherein the device comprises a pneumatic rapper actuator.

7. The device of claim 1, wherein the device comprises an electromagnetic actuator.

8. The device of claim 1, wherein the striker target assembly is movably disposed within the radiant synthesis gas cooler.

9. A striker target assembly for removing ash from an interior surface of a radiant synthesis gas cooler comprising:

a tube cage assembly defining a slot;

a striker target plate including a distal surface and a proximal surface, wherein the striker target plate extends through the slot; and

a wear plate mounted on the interior surface of the radiant synthesis gas cooler such that the wear plate is in contact with the distal surface of the striker target plate.

10. The striker target assembly of claim 9, wherein the striker target assembly is movably disposed within the radiant synthesis gas cooler.

11. The striker target assembly of claim 9, further comprising a striker pin in contact with the proximal surface of the striker target assembly.

12. The striker target assembly of claim 11, wherein the striker target plate, the striker pin, and the wear plate are all in alignment.

13. The striker target assembly of claim 9, wherein the striker target plate comprises two striker target plates.

14. The striker target assembly of claim 9, wherein the tube cage assembly comprises a membrane surrounding an outside surface of the tube cage assembly and the membrane defines an opening through which the striker target plate extends.

15. The striker target assembly of claim 14, further comprising a gap between the striker target plate and the membrane.

16. A method of removing ash from a radiant synthesis gas cooler comprising:

mounting a wear plate on an interior surface of the radiant synthesis gas cooler from which the ash is to be removed;

contacting a surface of the wear plate with a distal surface of a striker target plate that extends through a tube cage assembly of the radiant synthesis gas cooler;

contacting a proximal surface of the striker target plate with a striker pin; and

inducing a vibration in the interior surface, from which the ash is to be removed, by transmitting a rapping energy through the striker pin to the striker target plate and the wear plate.

17. The method of claim 16, further comprising aligning the wear plate, the striker target plate, and the striker pin.

18. The method of claim 16, further comprising producing a rapping energy using a rapper actuator.

19. The method of claim 16, further comprising mounting the striker target plate movably within the radiant synthesis gas cooler.

20. The method of claim 16, further comprising a striker target plate comprising two striker target plates.