DESC:FIELD
The present disclosure relates to boilers used in process industry and more particularly to an integrated water and a fire tube boiler for oil / gas firing application.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
At present, oil and gas fired boilers are either internal furnace smoke tube type or completely water tube type. In case of internal furnace smoke tube boilers, a furnace made out of rolled plates is placed inside a big drum where combustion of fuel takes place. The heat of the combustion and the flue gases then pass through numerous smoke tubes surrounded by water which gets converted into steam and in the process flue gases get cooled themselves. However, internal furnace boilers have a limitation of the furnace diameter as stipulated by various international design codes. Additionally, there is a limitation of the amount of heat that can be put in a furnace. This creates a limitation in terms of capacity of boiler and the pressure that it can handle. On the other hand, water tube boilers comprise a furnace made out of tubes that are connected to an elevated drum. In some cases, an additional water drum or mud drum is provided for containing the water tubes. Both the drums are then connected by numerous tubes through which water flows. However, water tube boilers have limited water stored within the drums and the tubes, which makes them less responsive to fluctuating steam loads in process application.
There is, therefore, felt a need to overcome the aforementioned problems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a boiler that offers a solution to overcome limitations on the capacity and the pressure at which steam is produced.
Another object of the present disclosure is to provide a boiler that offers an efficient response to fluctuating steam loads in process application.
Still another object of the present disclosure is to provide a boiler that requires less floor space area for installation.
Yet another object of the present disclosure is to provide a boiler which reduces the emissions.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages an integrated operative vertical boiler comprising a drum positioned at an operative top section for containing water and a furnace membrane positioned at an operative bottom section. The furnace membrane has a provision for a heating means at the operative front side of the boiler and a conduit means at the operative rear side of the boiler for conveying hot flue gases produced inside the furnace of the furnace membrane due to burning of fuel by the heating means. The boiler further comprises a steam outlet provided at the operative top end of the top section to extract steam produced in the boiler.
In one embodiment, the longitudinal axis of the drum is positioned offset from the longitudinal axis of the furnace membrane.
The boiler has dimensions of the furnace membrane varying along the length of the boiler and the furnace membrane is sealed from all sides.
A plate is attached to a rear side of the drum, the plate configured to direct the flue gases of combustion from around the furnace membrane into a plurality of smoke tubes of the drum. Further, a plurality of smoke tubes is disposed inside the drum and connected to the plurality of smoke tubes towards a front side of the drum for increased heat transfer.
The boiler further comprises drum support locations are provided on the drum.
The boiler includes a top header pipe and a plurality of riser pipes are disposed in between the furnace membrane and the drum. Additionally, a door is provided at the rear side for manual entry into the boiler.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The boiler of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a schematic of front end view of a boiler, in accordance with an embodiment of the the present disclosure;
Figure 2 illustrates a schematic of side view of the boiler of Figure 1;
Figure 3 illustrates a schematic of rear end view of the boiler of Figure 1;
Figure 4 illustrates a schematic of front end view of a boiler, in accordance with another embodiment of the present disclosure;
Figure 5 illustrates a schematic of rear end view of the boiler of Figure 4;
Figure 6 illustrates a schematic of front end view of a boiler, in accordance with yet another embodiment of the present disclosure; and
Figure 7 illustrates a schematic of rear end view of the boiler of Figure 6.
LIST OF REFERENCE NUMERALS
1 - top header, furnace top header
2 - riser pipe
3 - bottom header, furnace bottom header
4, 34, 64 - downcomer (vertical)
5 - downcomer (horizontal)
6 - main drum
7 - 2nd pass fire tubes
8 - 3rd pass fire tubes
9 - burner mounting location
10 - riser pipe connection to main drum
11 - drum support locations
12 - Rear door
13 - port for temperature / pressure measurement
14 - rear top header
15 - reversal chamber
16 – plurality of tubes
17 – furnace membrane
18 – flat strips
19 – airtight enclosure
20 – first zone
21 – second zone
22 – front side
23 – rear side
25 –back tube plate
26 – convection zone
27 – steam outlet
28 – top section
28a – top end of top section
29 – bottom section
6L – longitudinal axis of drum
17L – longitudinal axis of furnace membrane
41 – Rear Top Collector
42 – Rear Bottom Collector
66 – main bottom header
67 – horizontal collection pipe
100 – boiler
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
Figures 1-3 illustrate an embodiment of a boiler (100) of the present disclosure comprising a drum (6) disposed at a top section (28) of the drum (6). The drum (6) is positioned above a furnace membrane (17) positioned at a bottom section (29) of the boiler (100). The longitudinal axis (6L) of the drum (6) is positioned offset from the longitudinal axis (17L) of the furnace membrane (17). The drum (6) being disposed above the furnace membrane (17) reduces the floor space occupied by the boiler (100). A top header (1) and a bottom header (3) are connected by a plurality of water tubes (16) forming the furnace membrane (17). The plurality of water tubes (16) are connected with flat strips (18) forming an air tight enclosure (19). The air tight enclosure (19) of the furnace membrane (17) is completely sealed from all sides such that pressurised flue gases of combustion do not leak to atmosphere but can only travel along the span of the furnace membrane (17), i.e. from the front side (22) of the boiler (100) to the rear side (23) of the boiler (100). The air tight enclosure (19) of the furnace membrane (17) is divided into two zones, a first zone (20) in which combustion takes place and a second zone (21) through which hot flue gases of the first zone (20) pass, with no combustion taking place in second zone (21). Thus, the second zone (21) acts merely as a conduit means to provide a gas passage to the top section (28). The second zone (21) is taller than the first zone (20). The second zone (21) is connected to a back tube plate (25) on a rear side (23) of the drum (6). The dimensions of the first zone (20) and the second zone (21) are designed in a way to further cool the hot flue gases, thus completing the combustion process. The furnace membrane (17) does not directly connect to the drum (6), instead the furnace membrane (17) is connected to a top header pipe (1) which then further connects to the drum (6). Due to this, a convection zone (26) formed by the drum (6) is protected from heat radiated directly by the furnace membrane (17) thereby preventing overheating of drum (6), tubes (7) and back tube plate (25). The top header (1) and the drum (6) are connected together through a plurality of riser pipes (2). The plurality of riser pipes (2) are attached to the drum (6) by a plurality of riser pipe connections (10) provided on the drum (6). The bottom header (3) is fed with water continuously by a plurality of vertical downcomer pipes (4) and a plurality of horizontal downcomer pipes (5). The number of downcomer pipes (4,5) varies based on the boiler capacity and pressure. A heating means (9) is provided in the air tight enclcosure (19) to mount a burner (not shown in figure) for combustion process, thus constituting a first pass of the boiler (100). The drum (6) comprises a plurality of smoke tubes (7) that constitute a second pass of the boiler (100). Another plurality of smoke tubes (8) which constitute a third pass of the boiler (100) are contained inside the drum (6), and are separated horizontally in space from the second pass smoke tubes (7). Both the second pass smoke tubes (7) and the third pass smoke tubes (8) extend along the span of the furnace membrane (17) and carry hot flue gases. The number of riser connections (10) varies based on the boiler capacity and pressure. A rear door (12) is provided for carrying out inspection and maintenance of the boiler (100). A port (13) is provided for measurement of pressure and temperature of the flue gases inside a reversal chamber (15). The reversal chamber facilitates directing the flue gases into the plurality of second pass smoke tubes (7) mounted inside the drum (6). A rear top header (14) connects the plurality of water tubes (16) forming the reversal chamber (15). The drum (6) is supported at drum support locations (11) along the span of the drum (6). The convection zone (26) is supported at two planes so that the weight of the drum (6) is not transferred completely to the furnace membrane (17) with adequate support columns (not shown in figure) are provided for this purpose.
The working principle of the boiler (100) will now be described referring to figures 1-3. Bottom header (3) is fed water continuously by the plurality of downcomers (4 and 5) that further flows into the plurality of water tubes (16) of the furnace membrane (17). As a result of the combustion of fuel inside the first zone (20), water inside the furnace membrane (17) gets partially converted to steam. The mixture of water and steam is then fed to the top header (1) after which the plurality of risers (2) dispose this mixture into the drum (6) via the plurality of riser pipe connections (10). The steam generated is separated from water through a steam outlet (27) provided at a top end (28a) of the top section (28) of the drum (6). The steam generated into the furnace membrane (17) enhances the response of the boiler (100) to fluctuating steam load demands. The water inside the drum (6) is reheated by the heat of the flue gases flowing inside the second pass smoke tubes (7) and third pass smoke tubes (8). This enhances the efficiency of the boiler (100) as waste heat of flue gases is recovered in the main drum (6). Multiple pass smoke tubes (7,8) ensure increased dwelling time of flue gases which increases amount of heat recovery. The combustion process inside the furnace membrane (17) being confined to the first zone (20), emits flue gases carrying heat into the second zone (21). The flue gases then follow a direction from the front side (22) of the boiler (100) to the rear side (23) of the boiler (100) finally getting diverted by the reversal chamber (15) to be incident on the back tube plate (25). The back tube plate (25) has openings for the second pass smoke tubes (7) which allow passage of the flue gases that follow in a direction from the rear side (23) of the boiler (100) to the front side (22) of the boiler (100). The flue gases then pass through the third pass smoke tubes (8) as the end of second pass smoke tubes (7) and the start of third pass smoke tubes (8) open in a common front smoke chamber (not shown in the figure), and then finally exit the main drum (6) through other openings on the back tube plate (25).
Figures 4-5 illustrate another embodiment of the boiler (100) of the present disclosure. The longitudinal axis (6L) of the drum (6) is disposed horizontally offset to the furnace membrane (17). Thus the mixture of water and steam follows a horizontal path. A plurality of downcomers (34) connect the drum (6) to the bottom header (3). A rear top collector (41) and a rear bottom collector (42) constitutes a reversal chamber (15). The rest of the features of the second embodiment are similar in construction and working to the first embodiment illustrated in figures 1-3.
Figures 6-7 illustrate still another embodiment of a boiler (100) of the present disclosure. The longitudinal axis of the drum (6) is disposed vertically above the furnace membrane (17) due to which the mixture of steam and water follows a perfectly vertical path. A plurality of downcomers (64) connect the main drum (6) to a pair of main bottom headers (66) disposed on each side of the furnace membrane (17). The main bottom headers (66) are connected to a furnace membrane bottom header (3) through a plurality of horizontal pipes (67). The rest of the features of the third embodiment are similar in construction and working principle to the features of the first embodiment illustrated in figures 1-3.
In yet another ambodiment (not shown here), there can be only 2nd (second) pass tubes. Thus the flue gases will exit the boiler from the front side (22).
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an integrated boiler that:
• overcomes limitations on the amount of produced steam as well as the pressures at which steam is produced;
• offers an efficient response to fluctuating steam loads as required by the application;
• occupies less floor space for installation; and
• is eco-friendly to the environment that reduces emissions.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. An integrated operative vertical boiler (100) comprising a drum (6) positioned at an operative top section (28) for containing water and a furnace membrane (17) positioned at an operative bottom section (29); said furnace membrane (17) having a provision for a heating means (9) at the operative front side (22) of said boiler (100) and a conduit means (21) at the operative rear side (23) of said boiler (100) for conveying hot flue gases produced inside the furnace of said furnace membrane due to burning of fuel by said heating means (9); and a steam outlet (27) provided at the operative top end (28a) of said top section (28) to extract steam produced in said boiler (100), wherein said furnace membrane (17) is enveloped from all sides by a plurity of water tubes (16) forming said furnace membrane (17) and a reversal chamber (15).
2. The boiler (100) as claimed in claim 1, wherein the longitudinal axis (6L) of said drum (6) is positioned offset from the longitudinal axis (17L) of said furnace membrane (17).
3. The boiler (100) as claimed in claim 1, wherein dimensions of said furnace membrane (17) vary along the length of said boiler (100).
4. The boiler (100) as claimed in claim 1, wherein a back tube plate (25) is attached to a rear side (23) of said drum (6), said back tube plate (25) configured to direct said flue gases of combustion from around said furnace membrane (17) into a plurality of smoke tubes (7) of said drum (6).
5. The boiler (100) as claimed in claim 1, wherein a plurality of smoke tubes (8) are disposed inside said drum (6) and connected to said plurality of smoke tubes (7) towards a front side (22) of said drum (6) for increased heat transfer.
6. The boiler (100) as claimed in claim 1, wherein drum support locations (11) are provided on said drum (6).
7. The boiler (100) as claimed in claim 1, wherein a top header pipe (1) and a plurality of riser pipes (2) are disposed in between said furnace membrane (17) and said drum (6).
8. The boiler (100) as claimed in claim 1, wherein a door (12) is provided at said rear side (23) for manual entry into said boiler (100).