FIELD OF INVENTION
[001] The present invention relates to manhole assemblies and the like and more
particularly to a pass partition plate arrangement with multiple obround manway
openings in high pressure feed water heaters in thermal power plant.
BACKGROUND OF THE INVENTION
[002] In thermal power plants, feedwater heaters increase the efficiency of the plant
by the increasing the temperature of feedwater entering the boiler. With increase in
MW rating, more flow are heated through feedwater heaters (HP Heater & LP
heater).As a consequence the feedwater heater sizes are getting bigger in size. For
rectification or maintenance of heaters, operator has to enter inside the channel and
perform the inspection and rectification action.
[003] For high pressure feedwater heaters, pass partition plates are provided inside
the Hemispherical Channel head. This pass partition separates the cold and hot
Feedwater inside the HemiHead. For the purpose of inspection and maintenance of
tubes a manway opening is provided on the partition plate. As per HEI the minimum
manway opening dimension shall be elliptical 12” x 16”. It had been found the same
was adequate for a maintenance personal to go inside and check the condition of tubes.
To ensure that maintenance person can reach the farthest tube hole, the manway
opening is placed at the middle of the partition plate. For bigger heaters, this available
provision appeared to be inadequate and to alleviate that problem an innovative design
is developed so that tubes at the extreme left or right can be reachable for the
maintenance person.
[004] Existing prior art such as “CN209131481U “ discloses structure of shell-and-
tube heat exchanger pass partition, it is related to a kind of diaphragm structure, the
utility model is bad in order to solve the problems, such as existing pass partition
economy, it includes fluid outlet adapter tube, fluid inlet adapter tube, bobbin carriage

cylinder and tube sheet, fluid outlet adapter tube is connect with the outlet of bobbin
carriage cylinder upper surface, fluid inlet adapter tube is connect with the entrance of
bobbin carriage cylinder lower surface, and tube sheet is mounted on the right side of
bobbin carriage cylinder. A kind of structure of shell-and-tube heat exchanger pass
partition further includes pass partition, the pass partition is arranged in bobbin
carriage cylinder, the pass partition includes vertical clapboard, horizontal baffle and
manhole device, the upper end of vertical clapboard is connect with the intracorporal
top surface of bobbin carriage cylinder, the connection of the front end of vertical
clapboard and horizontal baffle, and the side of vertical clapboard is vertical with the
upper surface of horizontal baffle, the rear end of horizontal baffle and the middle part
of tube sheet connect, and manhole device is arranged on vertical clapboard. The
utility model is applied to shell-and-tube heat exchanger field.
[005] Another prior art such as “US20170260734A1” discloses a manhole base
assembly and a method for making the same employ a non-cylindrical, low-volume
concrete base that is fully lined to protect the concrete against chemical and physical
attack while in service. This lined concrete manhole base assembly may be readily
produced using a modular manhole form assembly which can be configured for a wide
variety of geometrical configurations compatible with, e.g., varying pipe angles,
elevations and sizes. The form assembly is configurable to provide any desired angle
and elevation for the pipe apertures to interface with various underground systems,
and can be formed on-site to facilitate compatibility with existing structures. The
assembly provides for flexible, modular construction of a wide variety of lined
manhole base assemblies at minimal cost, reduced concrete consumption and reduced
operational complexity. The modular nature of the production form assembly also
facilitates reduced inventory requirements when various manhole base assembly
geometries are needed.
[006] Thus the existing prior arts consists of multiple pieces horizontal pass partition
plate which are sequentially welded. Further it consists of one manhole on the vertical

partition plate. Further the shape of opening is also irregular. For bigger size heaters
single opening is not sufficient for easy maintenance.
[007] The present invention is directed to address the above problems and focus on
two obround shaped manhole openings. Further the present invention with an
innovative idea and with easy approach accommodate all the tubes.
OBJECTS OF THE INVENTION
[008] It is therefore a principal object of the present invention is to propose a pass
partition plate arrangement with multiple obround manway openings in feedwater
heaters in Thermal power plants which eliminates the disadvantages of prior art.
[009] Another object of the present invention is to propose the pass partition plate
arrangement with multiple obround manway openings such that tubes at the extreme
left or right is reachable for the maintenance person.
[0010] Another object of the present invention is to provide multiple obround shaped
openings adjacent to each other, so that both the HEI restrictions (i.e) min opening size
and max cover weight are met.
[0011] These and other objects and advantages of the present subject matter will be
apparent to a person skilled in the art after consideration of the following detailed
description taken into consideration with accompanying drawings in which preferred
embodiments of the present subject matter are illustrated.
SUMMARY OF THE INVENTION

[0012] This summary is provided to introduce concepts relates to a pass partition plate
arrangement with multiple obround manway openings in feed water heaters in thermal
power plant.
[0013] The present invention relates to the pass partition plate arrangement with
multiple obround manway openings in feed water heaters in thermal power plant
comprising fitting an inclined pass partition plate and welded to an inside surface of
Hemihead assembly which further comprises of a feed water (FW) inlet nozzle, a feed
water (FW) outlet nozzle and a manway nozzle which is positioned in the feed water
(FW) inlet side of the inclined pass partition plate. A horizontal pass partition plate is
welded to a tube sheet and to the inclined pass partition plate. The feed water (FW)
inlet nozzle and the feed water (FW) outlet nozzle are positioned to the opposite sides
of the inclined pass partition plate and the horizontal pass partition plate to separate
the cold feed water (FW) inlet and hot feed water (FW) outlet by two separate
chambers. The inclined pass partition plate is configured with multiple obround
manway openings. Each one of the multiple obround manway openings are of identical
shape and size, and are separated by a certain distance and each one of the multiple
obround manway openings are positioned such that the gap between the openings
and the distance between a farthest tube and openings is substantially less than the
arm length of a maintenance worker to inspect and perform maintenance of the farthest
tube.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0014] It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter and are therefore not to be considered for
limiting of its scope, for the invention may admit to other equally effective
embodiments. The detailed description is described with reference to the
accompanying figures. In the figures, a reference number identifies the figure in which

the reference number first appears. The same numbers are used throughout the figures
to reference like features and components. Some embodiments of system or methods
or structure in accordance with embodiments of the present subject matter are now
described, by way of example, and with reference to the accompanying figures, in
which:
[0015] FIG. 1 shows a schematic view of pass partition plate arrangement with single
manway opening in prior art;
[0016] FIG. 2 shows a Hemihead assembly with two section planes, horizontal Section
Plane A-A, and vertical Section Plane B-B in an embodiment of the present invention;
[0017] FIG. 3 shows a pass partition plate assembly (View B-B) in an embodiment of
the present invention; and
[0018] FIG. 4 shows a configuration of pass partition plate arrangement with multiple
obround manway openings (View A-A) in an embodiment of the present invention.
[0019] The figures depict embodiments of the present subject matter for the purposes
of illustration only. A person skilled in the art will easily 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.
Numerals detailed explanation:
1 Tube sheet
2 Hemihead (channel)
3 Manway Nozzle
4. Inclined pass partition plate
4’. Horizontal pass partition plate

5. Tube
6. Feedwater outlet Nozzle
6’. Feedwater inlet Nozzle
7. Stud with nut
8. Manway Opening Cover
9. Cover Handle
10. Gasket
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING
DRAWINGS
[0020] 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.
[0021] The terms “comprises”, “comprising”, or any other variations thereof used in
the disclosure, are intended to cover a non-exclusive inclusion, such that a device,
system, assembly that comprises a list of components does not include only those
components but may include other components not expressly listed or inherent to such
system, or assembly, or device. In other words, one or more elements in a system or
device proceeded by “comprises… a” does not, without more constraints, preclude the
existence of other elements or additional elements in the system or device.
[0022] FIG. 1 shows a schematic view of pass partition plate arrangement with single
manway opening in prior art. As the rating of power plant is increasing, equipment’s
for higher feed water flow, which in turn makes the equipment bigger. For higher

feedwater flow, the tube layout spreads out to bigger diameter. Hence during
maintenance it appears to be difficult for the maintenance person to reach the farthest
tube hole from the manway opening. In FIG. 1 the distance shown by “A” is the
distance from the outer most tube and the opening. When the distance “A” becomes
more than the arm length of the worker, it becomes difficult to perform inspection and
maintenance task for those distant tubes. If single big opening is created, then the
cover plate of the opening is made equally big to cover the opening. The manway
cover plate gets extremely bulky, and violates the codes restriction of maximum cover
weight (50 lb). Thus the single big opening concept is difficult for operation.
[0023] The present invention relates to a pass partition plate arrangement with
multiple obround manway openings in feed water heaters in thermal power plant.
[0024] FIG. 2 shows a Hemihead assembly (2) with two section planes, horizontal
Section Plane A-A, and vertical Section Plane B-B in an embodiment of the present
invention. In a preferred embodiment the Hemihead assembly (2) further comprises
a tube sheet (1), a feed water (FW) inlet nozzle (6’) and a feed water (FW) outlet
nozzle (6). In a preferred embodiment a high pressure feed water (FW) heater is a two
pass shall and tube heat exchanger and through the tubes (5) (shown in Fig.3) feed
water flows and over the tube (5) the steam flows. The feed water picks up the heat
from the steam and is fed to the boiler. The cold and hot feed water fluid is separated
by a solid plate called pass partition plate.
[0025] FIG. 3 shows a pass partition plate assembly (View B-B) in an embodiment of
the present invention. In a preferred embodiment a horizontal pass partition plate (4’)
is welded to a tube sheet (1). An inclined pass partition plate (4) is welded to an inside
surface of Hemihead assembly (2) and welded to the horizontal pass partition plate
(4’). The Hemihead assembly further consists of a manway nozzle (3). The feed water
(FW) inlet nozzle (6’) and the feed water (FW) outlet nozzle (6) are positioned to the

opposite sides of partition plates (4, 4’). The positioning of the inclined pass partition
plate (4) and the horizontal pass partition plate (4’) ensures that partition plates (4,4’)
separate the cold feed water (FW) inlet and hot feed water (FW) outlet by making two
separate chambers. In a preferred embodiment the manway nozzle (3) is placed in feed
water (FW) inlet side of the inclined pass partition plate (4). Further the pass partition
plate arrangement (100) comprises a plurality of the tubes (5) to be accommodated
such that farthest tube from the openings (14, 14’) (shown in FIG.4) are within the
reach of the maintenance operator.
[0026] In a preferred embodiment in the pass partition plate arrangement (100) a
manway cover (8) is fixed on the inclined pass partition plate (4) with a gasket (10)
and a stud with nut (7). The manway cover (8) consists of two cover handles (9) for
easy fit-up and removal.
[0027] FIG. 4 shows a configuration of the pass partition plate arrangement (100) with
multiple obround manway openings (14, 14’) in an embodiment of the present
invention. In the (View A-A), the pass partition plate arrangement (100) consist of a
multiple obround manway openings (14, 14’) of identical shape and identical size
separated by a distance, which to be calculated based on heater size and strength
analysis of the construction. In a preferred embodiment the multiple openings partition
plate thickness is checked by analysis. The horizontal pass partition plate (4’) welded
to the tube sheet (1) and the manway nozzle (3) is configured in feed water inlet side
of the inclined pass partition plate (4). The inclined pass partition plate (4) is further
welded to the inside surface of the Hemihead assembly (2).
[0028] In a preferred embodiment two obround manway openings (14, 14’) are
provided in the inclined pass partition plate (4) and horizontal pass partition plate (4’)
as shown in FIG. 4. Both openings (14, 14’) are of identical shape and size, and are
separated by a certain distance. The openings (14, 14’) are placed so that the gap

between the openings (14, 14’) and the distance between the farthest tube and opening
is less than the arm length of the maintenance worker. This type of configuration
ensures that worker inspect and perform maintenance of the farthest tube (5) with ease.
The pass partition plate arrangement (100) are configured to meet the requirements
and the design and manufacturing is simple due to the multiple obround shape and
identical size of openings (14, 14’). The pass partition plate arrangement (100) also
ensures that the HEI guidelines of minimum opening size and maximum manway
cover weight are met.
[0029] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in the
art that conception and specific embodiment disclosed may be readily utilized as a
basis for modifying or designing other structures for carrying out the same purposes
of the present subject matter. It should also be appreciated by those skilled in the art
that by devising various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter. Furthermore, all examples
recited herein are principally intended expressly to be for pedagogical purposes to aid
the reader in understanding the principles of the present subject matter and the
concepts contributed by the inventor(s) to furthering the art and are to be construed as
being without limitation to such specifically recited examples and conditions. The
novel features which are believed to be characteristic of the present subject matter,
both as to its organization and method of operation, together with further objects and
advantages will be better understood from the following description when considered
in connection with the accompanying figures.
[0030] These and other advantages of the present subject matter would be described
in greater detail with reference to the following figures. It should be noted that the
description merely illustrates the principles of the present subject matter. It will thus

be appreciated that those skilled in the art will be able to devise various arrangements
that, although not explicitly described herein, embody the principles of the present
subject matter and are included within its scope. The present invention will now be
described more specifically with reference to the following specification.
[0031] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled in the
art that conception and specific embodiment disclosed may be readily utilized as a
basis for modifying or designing other structures for carrying out the same purposes
of the present subject matter. It should also be appreciated by those skilled in the art
that by devising various arrangements that, although not explicitly described or shown
herein, embody the principles of the present subject matter and are included within its
spirit and scope. Furthermore, all examples recited herein are principally intended
expressly to be for pedagogical purposes to aid the reader in understanding the
principles of the present subject matter and the concepts contributed by the inventor(s)
to furthering the art and are to be construed as being without limitation to such
specifically recited examples and conditions. The novel features which are believed to
be characteristic of the present subject matter, both as to its organization and method
of operation, together with further objects and advantages will be better understood
from the following description when considered in connection with the accompanying
figures.
[0032] Although embodiments for the present subject matter have been described in
language specific to package features, it is to be understood that the present subject
matter is not necessarily limited to the specific features described. Rather, the specific
features and methods are disclosed as embodiments for the present subject matter.
Numerous modifications and adaptations of the system/device of the present invention
will be apparent to those skilled in the art, and thus it is intended by the appended

claims to cover all such modifications and adaptations which fall within the scope of
the present subject matter.
[0033] 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
particular 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 analogous 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.”
[0034] It will be further appreciated that functions or structures of a plurality of
components or steps may be combined into a single component or step, or the
functions or structures of one-step or component may be split among plural steps or
components. The present invention contemplates all of these combinations. Unless
stated otherwise, dimensions and geometries of the various structures depicted herein
are not intended to be restrictive of the invention, and other dimensions or geometries
are possible. In addition, while a feature of the present invention may have been
described in the context of only one of the illustrated embodiments, such feature may
be combined with one or more other features of other embodiments, for any given
application. It will also be appreciated from the above that the fabrication of the unique
structures herein and the operation thereof also constitute methods in accordance with
the present invention. The present invention also encompasses intermediate and end
products resulting from the practice of the methods herein. The use of “comprising”
or “including” also contemplates embodiments that “consist essentially of” or “consist
of” the recited feature.

[0035] Although embodiments for the present subject matter have been described in
language specific to structural features, it is to be understood that the present subject
matter is not necessarily limited to the specific features described. Rather, the specific
features and methods are disclosed as embodiments for the present subject matter.
Numerous modifications and adaptations of the system/component of the present
invention will be apparent to those skilled in the art, and thus it is intended by the
appended claims to cover all such modifications and adaptations which fall within the
scope of the present subject matter.

WE CLAIM:
1. A pass partition plate arrangement (100) with multiple obround manway openings
(14, 14’) in feed water heaters in thermal power plant comprising:
fitting an inclined pass partition plate (4) and welded to an inside surface of
Hemihead assembly (2) which further comprises of a feed water (FW) inlet nozzl e
(6’), a feed water (FW) outlet nozzle (6) and a manway nozzle (3) which is
positioned in the feed water (FW) inlet side of the inclined pass partition plate
(4);
a horizontal pass partition plate (4’) is welded to a tube sheet (1) and to the
inclined pass partition plate (4);
the feed water (FW) inlet nozzle (6’) and the feed water (FW) outlet nozzle (6)
are positioned to the opposite sides of the inclined pass partition plate (4) and
horizontal pass partition plate (4’) to separate the cold feed water (FW) inlet and
hot feed water (FW) outlet by two separate chambers; wherein
the inclined pass partition plate (4) is configured with multiple obround
manway openings (14, 14’);
each one of the multiple obround manway openings (14, 14’) are of identical
shape and size, and are separated by a certain distance; and
each one of the multiple obround manway openings (14, 14’) are positioned
such that the gap between the openings (14, 14’) and the distance between a
farthest tube (5) and openings (14, 14’) is substantially less than the arm length
of a maintenance worker to inspect and perform maintenance of the farthest tube
(5).