A modularised electric resistance heater steam electric boiler

Abstract

The present disclosure envisages a modularised electric resistance heater steam electric boiler (100) comprising a drum (102) for accumulating water and separating steam from a steam-water mixture At least one downcomer (104) extends vertically downward from the drum (102) and connects perpendicularly to a first connecting pipe (106). Heater pipes (108) extend perpendicularly from the first connecting pipe (106), each heater pipe having a lower end in fluid communication with the first connecting pipe (106) to receive water and an upper end for discharging a steam-water mixture. At least one electric heater (110) is associated with each heater pipe (108) to heat water therein and generate the steam-water mixture. The mixture is conveyed through at least one second connecting pipe(s) (112) extending from the heater pipes (108) and is directed to the drum (102) through at least one riser pipe (116), to enable steam separation within the drum (102).

Description

[0001] A MODULARISED ELECTRIC RESISTANCE HEATER STEAM ELECTRIC BOILER

[0002] FIELD

[0003] The present disclosure relates to electric steam boilers.

[0004] DEFINITION

[0005] Riser pipe - The term ‘riser pipe’ herein in this disclosure, refers to a conduit for carrying a mixture of water and steam from the heated unit up to the steam drum by forming a natural circulation circuit.

[0006] Collector pipe - The term ‘collector pipe’ herein in this disclosure, refers to a conduit that accumulates process media (water, steam or a mixture thereof) across various heating units.

[0007] BACKGROUND

[0008] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0009] Electric boilers are widely used in various industrial applications for generating steam. These boilers primarily use resistance heaters to heat water and generate steam. Electric steam boilers generally have a drum configuration, and are available in both horizontal and vertical configurations.

[0010] The heaters can be incorporated as a single electric heater bundle or as a plurality of electric heater bundles. In the horizontal configuration of the boiler, the heater bundles are typically inserted from one or both ends of the drum either with the help of a flanged nozzle or are directly fixed onto the flat tube sheet of the drum. In the vertical configuration of the boiler, the heater bundles are inserted from the top inside of the drum, but the top portion of the heater bundle is not immersed in water.

[0011] However, these existing heaters suffer from several limitations. Horizontal drum boilers require a large amount of floor space, and additional clearance is necessary for heater bundle removal during maintenance or replacement. Additionally, the size of the drum in both horizontal and vertical configurations is relatively large, leading to increased material thickness requirements, higher water content, and longer startup times. The higher water content also results in slowerresponses to pressure variations, affecting operational efficiency. Furthermore, complete drainage of the boiler is often required for heater replacement, adding to maintenance downtime and operational inefficiencies.

[0012] Therefore, there is felt a need for a modularised electric resistance heater steam electric boiler.

[0013] OBJECTS

[0014] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0015] It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

[0016] An object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler.

[0017] Another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that has relatively reduced floor space required for the boiler.

[0018] Still another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that eliminates the need of additional space required in front or rear of boiler for heater bundle removal.

[0019] Yet another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that has relatively reduced overall water content of boiler.

[0020] Another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that has a compact configuration.

[0021] Yet another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that is user friendly.

[0022] Still another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that minimises drainage of the boiler water in case of heater maintenance or replacement.

[0023] Yet another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that is cost effective.Still another object of the present disclosure is to provide a modularised electric resistance heater steam electric boiler that exhibits a relatively faster response to load and pressure variations.

[0024] Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.

[0025] SUMMARY

[0026] The present disclosure envisages a modularised electric resistance heater steam electric boiler. The electric boiler comprises a drum that is configured to accumulate and separate steam from a steam-water mixture. At least one downcomer extends vertically downwards from the drum. At least one first connecting pipe is connected perpendicular to the downcomer. A plurality of heater pipes is configured to extend perpendicularly from the first connecting pipe. Each heater pipe defines an operative lower end that is configured to fluidly communicate with the first connecting pipes for receiving water therefrom. Each heater pipe further defines an operative upper end. At least one electric heater is connected to each heater pipe. The heater is configured to facilitate heating of water contained inside the heater pipe for producing a mixture of steam and water. At least one second connecting pipe(s) extends perpendicularly from the heater pipes to receive the steam-water mixture from the operative upper end of the heater pipes. At least one riser pipe is configured to extend from the drum. The riser pipe is further configured to fluidly communicate with the second connecting pipe(s) to receive the steam-water mixture therefrom, and facilitate upward discharge of the steam-water mixture to the drum.

[0027] In an embodiment, the second connecting pipe is a single pipe configured to extend along the length of the heater pipes.

[0028] In another embodiment, the second connecting pipe is defined by a plurality of pipes. Each pipe is configured to extend perpendicularly from a respective heater pipe.

[0029] In an embodiment, the boiler includes a collector pipe that is configured to be fluidly connected to the second connecting pipe(s) and to the riser pipe to facilitate fluid communication therebetween.

[0030] In another embodiment, each electric heater is removably provided in the respective heater pipe through the operative top end thereof in a vertically downward direction.In yet another embodiment, the heater pipes are arranged in parallel to an operative longitudinal axis of the main drum.

[0031] In an embodiment, the drum includes a set of level gauges that are configured to enable continuous monitoring of the water and steam.

[0032] BRIEF DESCRIPTION OF ACCOMPANYING DRAWING

[0033] A modularised electric resistance heater steam electric boiler of the present disclosure will now be described with the help of the accompanying drawing, in which:

[0034] Figure 1 illustrates a block diagram of the electric boiler of the present disclosure; and Figure 2 illustrates a line drawing of the boiler of the present disclosure.

[0035] LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING

[0036] 100 - Boiler

[0037] 102 - Drum

[0038] 104 - Downcomers

[0039] 106 - Water connecting pipe

[0040] 108 - Heater pipe

[0041] 110 - Electric heater

[0042] 112 - Steam connecting pipe

[0043] 114 - Collector pipe (Optional)

[0044] 116 - Riser pipe

[0045] DETAILED DESCRIPTION

[0046] 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.

[0047] 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, elements, modules, units, and / or components, but do not forbid the presence or addition of one or more other features, elements, components, and / or groups thereof.

[0048] A modularised electric resistance heater steam electric boiler of the present disclosure will now be described in detail with reference to Figure 1 and Figure 2. The preferred embodiment does not limit the scope and ambit of the present disclosure.

[0049] The boiler (100) comprises a drum (102). The drum (102) is a pressure vessel configured to accumulate and separate steam from a steam-water mixture returned to it from the heater pipe array. The drum (102) defines atop region in which separated steam accumulates for supply to a downstream process load, and a bottom region. In an embodiment, the orientation of the drum (102), whether horizontal, vertical, or inclined is determined by site and installation requirements and does not affect the operation of the thermosiphon circuit described herein. In another embodiment, water is introduced into the drum (102) prior to startup by means of suitable feed pumps. During normal operation, the water level within the drum (102) is maintained at a level sufficient to ensure continuous gravity-driven flow into the downcomers (104) while preserving adequate steam disengagement space in the top region of the drum. At least one downcomer (104) is configured to extend vertically downwards from the drum (102). At least one first connecting pipe (106) is connected perpendicular to the downcomer (104). The downcomer (104) provides the primary descending water feed path from the bottomregion of the drum (102) to the first connecting pipe (106). The downcomer (104) is oriented vertically so that cooler, denser water descends under gravity from the drum ( 102) into the inlet manifold formed by the first connecting pipe (106).

[0050] A plurality of heater pipes (108) is configured to extend perpendicularly from the first connecting pipe (106), thus being arranged externally of and adjacent to the drum (102). Each heater pipe (108) defines an operative lower end and an operative upper end. The operative lower end of each heater pipe (108) is configured to fluidly communicate with the first connecting pipe (106) for receiving water therefrom. In an embodiment, the first connecting pipes (106) collectively form a common horizontal inlet manifold extending along the base of the array of heater pipes (108). As a result, water distribution to the heater pipe array is substantially simultaneous and uniform across all modules. No sequential or staged filling of individual heater pipes (108) occurs during startup or refilling after a maintenance operation. This parallel distribution arrangement ensures consistent water supply to each heater pipe (108) irrespective of its position within the array.

[0051] The perpendicular orientation of the heater pipes (108), with respect to the first connecting pipe (106), is an essential feature of the invention. By arranging the heater pipes (108) vertically and external to the drum (102), the boiler (100) achieves a compact footprint substantially reduced relative to a conventional horizontal single-shell electric boiler of equivalent capacity. Further, the individual heater pipes (108) are of comparatively smaller diameter than a single equivalent-capacity shell drum. As a result, the aggregate water volume of the circuit is substantially reduced compared to a conventional single-shell electric boiler of equivalent steam-generating capacity. This reduction in water inventory directly shortens boiler startup time and accelerates pressure response to fluctuating load demands.

[0052] At least one electric heater (110) is connected to each heater pipe (108). The electric heater (110) is configured to heat the water contained inside the heater pipe (108) and produce a steam-water mixture. In an embodiment, the electric heater (110) is a resistance-type heater. Each electric heater (110) is provided with its own independent electrical supply connection; whereby individual heaters may be selectively energised or de-energised for stepwise load control. In the event of a fault in any single heater (110), that particular heater (110) is deenergised and isolated while the remaining modules continue to operate, maintaining partial load availability pending repair or replacement. Therefore, an electrical fault in any single heater (110) does not impair the continued operation of the remaining heaters or the boiler(100) as a whole, and the independent supply arrangement simplifies cabling, installation, and fault diagnosis relative to a single large heater bundle serving an equivalent-capacity singleshell boiler.

[0053] At least one second connecting pipe(s) (112) is configured to extend perpendicularly from to the heater pipes (108) to receive the steam-water mixture discharged from the operative upper end of each heater pipe. As the electric heater (110) within each heater pipe (108) heats the water, a portion of the water is converted to steam. The resulting steam-water mixture rises within the heater pipe (108) toward the operative upper end and exits through the second connecting pipe(s) (112). The second connecting pipe(s) (112) provides a common horizontal discharge path through which the steam -water mixture from each heater pipe (108) is consolidated and conveyed toward the collector pipe (114).

[0054] At least one riser pipe (116) is configured to extend from the drum (102). The riser pipe (116) is further configured to fluidly communicate with the second connecting pipe(s) (112) to receive the steam-water mixture therefrom, and facilitate upward discharge of the steam-water mixture into the drum (102).

[0055] Thus, the second connecting pipe(s) (112) provides a common horizontal discharge path through which the steam-water mixture from each heater pipe (108) is consolidated and conveyed toward the collector pipe ( 114) or directly to steam drum via the riser pipe (116). The drum (102), the heater pipes (108), and the interconnecting pipework collectively form a closed thermosiphon circulation circuit through which water is continuously supplied to the heater pipes, converted into a steam-water mixture, and returned to the drum for steam-water separation. The density differential between the descending cool water in the downcomer ( 104) and the buoyant steam -water mixture ascending through the riser pipe (116) is the motive force for the natural thermosiphon circulation of the boiler (100), which operates without requiring a separate mechanical circulation pump. This distributed configuration fundamentally departs from conventional single-shell configurations in that no electric heater is housed within the drum itself; instead, each heater pipe (108) constitutes an independent, self-contained heating module receiving water from a common inlet manifold and discharging a steam-water mixture into a common outlet header. The riser pipe (116) completes the thermosiphon circulation loop by returning the steam-water mixture from the heater pipe array to the steam-water separation space of the drum (102). Within the drum (102), the steam phase separates from the waterphase; separated steam accumulates in the top region for supply to the downstream load, while the separated water remains in the bottom region for recirculation through the downcomer (104). The buoyancy of the ascending steam -water mixture within the riser pipe (116) relative to the descending cool water in the downcomer (104) sustains natural thermosiphon circulation continuously during operation.

[0056] In an embodiment, the second connecting pipe (112) is a single pipe configured to extend along the length of the heater pipes (108). In another embodiment, the second connecting pipe (112) is defined by a plurality of pipes. Each pipe is configured to extend perpendicularly from a respective heater pipe (108).

[0057] In an embodiment, the boiler (100) includes a collector pipe (114) be fluidly connected to the second connecting pipe(s) (112) and to the riser pipe (116) to facilitate fluid communication therebetween. In another embodiment, the collector pipe (114) thus forms a common steamwater mixture outlet header for the entire heater pipe array. The collector pipe (114) receives the consolidated steam-water mixture from the second connecting pipe(s) (112) and delivers it to the riser pipe (116) for recirculation to the drum (102). The collector pipe (114) is configured to accommodate the combined steam -water flow from all heater pipes (108) operating simultaneously at full load without excessive flow velocity or pressure drop. The interposition of the collector pipe (114) between the second connecting pipe(s) (112) and the riser pipe (116) simplifies the piping arrangement and provides a single, well-defined handover point between the heater pipe array and the return circuit to the drum (102).

[0058] In one embodiment, each electric heater (110) is removably provided in the respective heater pipe (108) through the operative upper end thereof in a vertically downward direction. The heater (110) may be withdrawn from the respective heater pipe (108) by pulling it vertically upward through the operative upper end, and a replacement heater may be inserted by lowering it vertically downward through the same opening. This arrangement requires no dismantling of adjacent pipework and no lateral access space.

[0059] In an embodiment, the heater pipes (108) are arranged in parallel to an operative longitudinal axis of the main drum (102). This parallel arrangement positions the heater pipe array alongside the drum (102) in a space-efficient configuration. The first connecting pipe (106) at the base of the array and the second connecting pipe(s) (112) at the top of the array run transversely between adjacent heater pipes (108), and the collector pipe (114) runs longitudinally along thearray parallel to the drum axis to collect the steam-water mixture from the second connecting pipe(s) (112). This configuration results in a compact, rectangular overall footprint that is well-suited to industrial boiler room layouts.

[0060] In one embodiment, the drum (102) includes a set of level gauges configured to enable continuous monitoring of the water and steam within the drum. The level gauges are mounted on dedicated instrument connections provided on the drum (102) and give a direct indication of the water level within the steam-water separation space of the drum independently of the water level within the individual heater pipes (108). Continuous level monitoring enables the boiler operator to maintain the water level within the drum (102) within the required operating range, ensuring adequate water supply to the downcomer (104) and appropriate steam disengagement space in the top region of the drum.

[0061] The foregoing description of the embodiments has been provided for purposes of illustration and is 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.

[0062] TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE

[0063] The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a modularised electric resistance heater steam electric boiler, that:

[0064] • has relatively reduced floor space required for the boiler;

[0065] • eliminates the need of additional space required in front or rear of boiler for heater bundle removal;

[0066] • has relatively reduced overall water content of boiler;

[0067] • has a compact configuration;

[0068] • is user-friendly;

[0069] • exhibits a relatively faster response to load and pressure variations;

[0070] • minimises drainage of the boiler water in case of heater replacement; and

[0071] • is cost effective.The foregoing description of the specific embodiments so fully reveals 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.

[0072] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, or group of elements, but not the exclusion of any other element, or group of elements.

[0073] 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

CLAIMS:

1. A modularised electric resistance heater steam electric boiler (100) comprising:• a drum (102) configured to accumulate and separate steam from a steam-water mixture;• at least one downcomer ( 104) configured to extend vertically downward from the drum (102);• at least one first connecting pipe (106) connected perpendicular to the downcomer (104);• a plurality of heater pipes (108) configured to extend perpendicularly from the first connecting pipe (106), each heater pipe (108) defining an operative lower end configured to fluidly communicate with the first connecting pipe (106) to receive water therefrom, and an operative upper end;• at least one electric heater (110) connected to each heater pipe (108), the heater (110) configured to facilitate heating of water contained inside the heater pipe for producing a mixture of steam and water;• at least one second connecting pipe(s) (112) extending perpendicularly from the heater pipes (108) to receive the steam-water mixture from the operative upper end of the heater pipes (108); and• at least one riser pipe (116) configured to extend from the drum (102), the riser pipe (116) further configured to fluidly communicate with the second connecting pipe(s) (112) to receive the steam-water mixture therefrom, and facilitate upward discharge of the steam-water mixture to the drum (102).

2. The electric boiler (100) as claimed in claim 1, wherein the second connecting pipe (112) is a single pipe configured to extend along the length of the heater pipes (108).

3. The electric boiler (100) as claimed in claim 1, wherein the second connecting pipe (112) is defined by a plurality of pipes, each pipe being configured to extend perpendicularly from a respective heater pipe (108).

4. The electric boiler (100) as claimed in claim 2 and 3, wherein the boiler (100) includes a collector pipe (114) configured to be fluidly connected to the second connecting pipe(s) (112) and to the riser pipe (116) to facilitate fluid communication therebetween.

5. The electric boiler (100) as claimed in claim 1, wherein each electric heater (110) is removably provided in the respective heater pipe (108) through the operative top end thereof in a vertically downward direction.

6. The electric boiler (100) as claimed in claim 1, wherein the heater pipes (108) are arranged in parallel to an operative longitudinal axis of the main drum (102).

7. The electric boiler (100) as claimed in claim 1, wherein the drum (102) includes a set of level gauges configured to enable continuous monitoring of the water and steam.

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