Description:“ARRANGEMENT TO PREVENT LEAKAGE OF ASH FROM SUPER CRITICAL STEAM GENERATOR BASED THERMAL POWER PLANTS”

FIELD OF THE INVENTION:

[0001] This invention relates to an arrangement based on ceramic fiber, refractory adhesive and steel fixing components called Ash Leakage Prevention Solution (ALPS) that will be used to prevent leakage of ash from steam-cooled wall, roof and rear arch areas of super critical Steam Generator based thermal power plants. This invention more particularly relates to in situ installation of a composite fabric comprising multiple layers of ceramic blanket, refractory coating and steel components that are flexible, easy to install in areas of ash leakages that are observed while boiler is in operation.

BACKGROUND OF THE INVENTION:

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] During operation of thermal power plant, a lot of ash is generated by burning of coal. This ash ingress through the expansion gap provisions, damages the expansion seals and finally leaks out of boiler. Ash leakages have been observed in steam-cooled sidewall and roof panel intersection areas, roof panel expansion bellow areas, rear arch panels and extended pass intersection areas. The ash leakages in roof panel area of boiler cause penetration into boiler penthouse, accumulation on top of tube panels, skin casing components and expansion bellows. The accumulated ash thus requires frequent cleaning related maintenance works. More over the fine ash dust gets suspended in air and thereby causing air pollution in the nearby boiler areas.

[0004] A flexible sealing solution is thus required for preventing the ash leakage areas in boiler. Hence, the present invention has been proposed.

OBJECTS OF THE INVENTION:

[0005] An object of the invention is to provide arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants.

[0006] Another object of the present invention is to provide a composite layered design that prevents ash from passing through it and at the same time provides flexibility to thermal expansion movements of steam-cooled panels.

[0007] Still another object of the invention is to provide arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants with easier installation, high temperature withstanding ability and long life period to resist ash leakages from boiler.

[0008] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:

[0009] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.

[0010] According to the present invention, there is provided Arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants comprising of:

[0011] welding of fixing pins (04) to the fins at regular intervals in the area of ash leakages,

[0012] lining the area with a layer of ceramic fiber blanket (01), where the ash sealing is to be carried out,

[0013] providing a layer of refractory coating (02) over the layer of Ceramic fiber blanket (01),

[0014] wrapping a second layer of the ceramic fiber blanket (01) around the already applied coating (02),

[0015] wrapping a steel wire mesh (05) around the layers formed using the ceramic fiber blanket (01),

[0016] welding the retainer (03) to the fixing pins (04),

[0017] applying a layer of refractory coating (02) after securing the composite layers of ceramic fiber blanket (01), refractory coating (02) using mesh (05).

[0018] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0019] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0020] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING:

[0021] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

[0022] Figure 1 shows: Arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants according to the present invention.

[0023] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION WITH REFERENCE TO THE DRAWING:

[0024] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0025] The present invention makes a disclosure regarding a technology pertaining to an invention directing to arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants.

[0026] The Ash Leakage Prevention System (ALPS) of instant invention comprises of installing composite layers of ceramic fiber blankets with refractory coating which are secured safely by a steel mesh using steel fixing components in locations where ash leakages happen. The layers of blanket with refractory coating ensures flexibility of steam cooled wall along with the fabric. A coating of refractory adhesive between layers of ceramic blanket and on the outside of steel mesh ensures that ash cannot pass through these impermeable layers. The composite layers of fabric and mesh are locked in respective positions using steel pins, retainers that are supported from the nearby flat surfaces in steam-cooled walls of boiler. This arrangement can withstand high temperatures of boiler operations up to 9500C.

[0027] The surface of tubes, fins, metallic bellows and other metallic surfaces must be cleaned by using brush/compressed air so that the surfaces where Ash Leakage Prevention Solution (ALPS) is to be applied are free from dust, ash or any other foreign particles.

[0028] Now, reference may be made to figure 1. Steel fixing pins (04) are welded to the fins at regular intervals in the area of ash leakages. The area where the ash sealing is to be carried out is to be first lined with a layer ceramic fiber blanket (01). A thin layer of refractory coating (02) is provided over the 1st layer of Ceramic fiber blanket (01). A second layer of ceramic fiber blanket (01) is wrapped around the already applied coating. Then a steel wire mesh (05) is wrapped around the layers formed using ceramic fiber blanket (01). Steel wire mesh (05) is then properly inserted into the steel fixing Pins (04). A steel retainer (03) is used to lock the steel wire mesh (05) with Steel fixing pins (04). Retainer (03) is tack welded to the steel fixing pins (04) after inserting the Steel mesh in position. After securing the composite layers of ceramic fiber blanket (01), refractory coating (02) using Steel mesh (05), a final layer of refractory coating (02) is to be applied using hand brush.

[0029] The arrangement of sealing based on ceramic fiber, refractory adhesive and steel fixing components can be utilized in super critical boilers.

Advantages of Invention

[0030] - Serves the purpose of arresting ash leakage by being impermeable and also accommodates differential thermal expansion movements of steam cooled walls by being flexible,
[0031] - Performs at high temperatures of up to 9500C,
[0032] - Easy to install during boiler maintenance shutdown,
[0033] - Reduction in the maintenance activities and pollution due to ash accumulation.

WORKING OF THE INVENTION

[0034] This invention prevents ingress of ash through various layers as shown in Fig 1. The refractory adhesive and layers of ceramic blanket form flexible yet impermeable sheath that prevents ash to travel through. The travel of ash from hot flue side of boiler is prohibited through these impermeable layers of refractory adhesive and blankets.

[0036] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0037] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0038] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0039] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0041] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0042] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:We Claim

1. Arrangement to prevent leakage of ash from super critical Steam Generator based thermal power plants comprising of:

Welding of fixing pins (04) to the fins at regular intervals in the area of ash leakages,

Lining the area with a layer of ceramic fiber blanket (01), where the ash sealing is to be carried out,

Providing a layer of refractory coating (02) over the layer of Ceramic fiber blanket (01),

Wrapping a second layer of the ceramic fiber blanket (01) around the already applied coating (02),

Wrapping a steel wire mesh (05) around the layers formed using the ceramic fiber blanket (01),

Welding the retainer (03) to the fixing pins (04),

applying a layer of refractory coating (02) after securing the composite layers of ceramic fiber blanket (01), refractory coating (02) using mesh (05).

2. The Arrangement to prevent leakage of ash as claimed in claim 1, wherein the wire mesh (05) is inserted into the fixing Pins (04).

3. The Arrangement to prevent leakage of ash as claimed in claim 1, wherein the retainer (03) is provided to lock the wire mesh (05) with the fixing pins (04).

4. The Arrangement to prevent leakage of ash as claimed in claim 1, wherein the retainer (03) is tack welded to the fixing pins (04) after inserting the mesh (05) in position.

5. The Arrangement to prevent leakage of ash as claimed in claims 1-4, wherein the retainer (03), the fixing pins (04) and the mesh (05) are made of metal including Steel.