The present disclosure generally relates to the field of down-flow reactors. Particularly, but not exclusively, the present disclosure relates to the construction and mechanism of a novel gas-liquid inlet diffuser for concurrent down flow trickle bed reactor. Further, embodiments of the present disclosure an inlet distribution apparatus for process gases and liquids in a concurrent trickle bed reactor that minimizes flow asymmetry of an inlet fluid.
BACKGROUND
Generally, in a petroleum refinery, fixed bed reactors are employed in hydro processing, reforming and various chemical production reactors. Such fixed bed reactors use concurrent down flow of a fluid such as gas or gas-liquid mixture or the like, through beds of solid catalyst. For the purpose of efficient refinement, these reactors need optimum fluid distribution near the inlet of the reactor. Optimal reactor performance and control may be achieved only when the fluids are uniformly distributed across entire catalyst bed area, so that all the catalyst is contacted by the flowing reactant fluids.
In conventionally known reactors, at the inlet nozzle, fluids are distributed over one or more downstream trays or catalyst beds. The reactors are generally configured with a single inlet pipe that approaches an inlet of the reactor horizontally. For directing the inlet fluids in the downward direction, a connecting means such as a 90° elbow may be provided at the inlet to connect the horizontal inlet pipe with the reactor. Further, there may be provided an inlet nozzle for evenly distributing the inlet fluid in the reactor. Ideally, an inlet nozzle should be configured to erase all angular and radial asymmetries imparted by approach piping, thereby achieving uniform coverage over the tray or solids bed below. Additionally, the entering fluid momentum should be reduced to prevent high velocity erosion of the shell, internals, or solids bed. Fluids at high velocity can

splash off this pre-distributor tray to the final distributor tray, thus compromising two-phase distribution. One more limitation is that the pressure drop across inlet nozzle must be acceptable for optimal reactor flow rates and the distributor must not allow excessive coking and solid accumulation.
Therefore, the researchers have developed a technically advanced mechanism that overcomes the one or more disadvantages associated with the conventional reactors. More specifically, a novel gas-liquid inlet diffuser for down flow reactor that provides optimum distribution of the inlet fluid so as to overcome one or more drawbacks stated above.
SUMMARY
One or more drawbacks of conventional down-flow reactors as described in the prior art are overcome and additional advantages are provided by the novel gas-liquid inlet diffuser for down-flow reactor 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 a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, there is provided a novel gas-liquid inlet diffuser for down flow reactor having a cylindrical housing comprising a hollow internal space. The improved downflow reactor comprises an inlet pipe being configured with the housing to define an inlet of the down flow reactor. An inlet diffuser is located in the hollow internal space of the housing at the inlet. The inlet diffuser comprises an annular chamber having a fluid inlet formed upwardly towards the inlet of the down flow reactor and a fluid outlet formed downwardly. A plurality of vertical baffles to impart uniform discharge to a fluid exiting the annular chamber thereby minimizing flow asymmetry and breaking fluid momentum in a vertically downward direction. The inlet diffuser further comprises a plurality of sieve plates disposed downwardly of the fluid outlet. The plurality of sieve plates is configured to uniformly distribute the fluids exiting the annular chamber. A distributor tray is configured below the inlet diffuser in a region above a catalyst bed of the down flow reactor.

In an embodiment of the present disclosure, the inlet pipe is connected with the housing by means of a 90° elbow so as to feed the fluid perpendicularly along a vertical axis XX.
In another embodiment of the present disclosure, the splash plate comprises a central aperture to allow at least a part of the fluid from the inlet pipe to pass therethrough.
In an embodiment of the present disclosure, the splash plate is configured to radially divert at least a part of the fluid from the inlet pipe towards an inner periphery of the annular chamber.
In an embodiment, the annular chamber of the inlet diffuser has a larger diameter than the inlet Pipe-In an embodiment, the baffles are mounted circumferentially along an inner periphery of the annular chamber.
In an embodiment, the vertical slots are provided to divert fluids from annular chamber to the central hollow space.
In yet another embodiment, the plurality of sieve plates is a combination of different sieve plates disposed at multiple levels with respect to one another.
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 with reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and

advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
Figure 1 is sectional view of an improved down-flow reactor in accordance with the present disclosure.
Figure 2 is a front view of the fluid inlet diffuser of the improved down-flow reactor of Figure 1, according to an embodiment of the present disclosure.
Figure 3 is the top view of the vertical baffles of the novel gas-liquid inlet diffuser for down-flow reactor of Figure 1, according to an embodiment of the present disclosure.
Figure 4 is a perspective top view of the inlet diffuser showing the annular solid portion on the top plate for splash.
Figure 5 depicts the one or more sieve plate type splash plates in accordance with the fluid inlet diffuser of the improved down-flow reactor of Figure 1.
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 assemblies and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
While the invention is subject to various modifications and alternative forms, specific embodiment thereof has 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 invention to the particular forms

disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and scope of the invention as defined by the appended claims.
Before describing in detail, the various embodiments of the present disclosure it may be observed
5 that the novelty and inventive step that are in accordance with a novel gas-liquid inlet diffuser for
down-flow reactor. It is to be noted that a person skilled in the art can be motivated from the present disclosure and can perform various modifications. However, such modifications should be construed within the scope of the invention.
10 Accordingly, the drawings are showing only those specific details that are pertinent to
understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
15 The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-
exclusive inclusion, such that an assembly, setup, system, device 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 device or setup. In other words, one or more elements in the system or apparatus or device proceeded by “comprises a” does not, without more
20 constraints, preclude the existence of other elements or additional elements in the assembly or
system or apparatus. The following paragraphs explain present disclosure. The invention in respect of the same may be deduced accordingly.
Accordingly, it is an aim of the present disclosure to provide a novel gas-liquid inlet diffuser for
25 down-flow reactor whereby all angular and radial asymmetries of an inlet fluid due to inlet piping
are erased, thereby achieving uniform coverage over the tray or solids bed below.
One more aim of the present disclosure is to provide a novel gas-liquid inlet diffuser for down-
flow reactor that provides for breaking momentum of the inlet fluid to prevent high velocity
30 erosion of the shell, internals, or solids bed.
6

One more aim of the present disclosure is to provide a novel gas-liquid inlet diffuser for down-flow reactor whereby pressure drop across inlet nozzle is acceptable for optimal reactor flow rates.
Another aim of the present disclosure is to provide a novel gas-liquid inlet diffuser for down-flow
5 reactor whereby fluid distributor does not allow excessive coking and solid accumulation.
In one non-limiting embodiment of the present disclosure, there is provided improved down flow reactor having a cylindrical housing comprising a hollow internal space. The novel gas-liquid inlet diffuser for downflow reactor comprises an inlet pipe being configured with the housing to define
10 an inlet of the down flow reactor. An inlet diffuser is located in the hollow internal space of the
housing at the inlet. The inlet diffuser comprises an annular chamber having a fluid inlet formed upwardly towards the inlet of the down flow reactor and a fluid outlet formed downwardly. A plurality of vertical baffles to impart uniform discharge to a fluid exiting the annular chamber thereby minimizing flow asymmetry and breaking fluid momentum in a vertically downward
15 direction. The inlet diffuser further comprises a plurality of sieve plates disposed downwardly of
the fluid outlet as shown in Figure 6. The plurality of sieve plates is configured to uniformly distribute the fluids exiting the annular chamber. A distributor tray is configured below the inlet diffuser in a region above a catalyst bed of the down flow reactor. The inlet pipe is connected with the housing by means of a 90o elbow so as to feed the fluid perpendicularly along a vertical axis
20 XX. The splash plate comprises a central aperture to allow at least a part of the fluid from the inlet
pipe to pass therethrough. The splash plate is configured to radially divert at least a part of the fluid from the inlet pipe towards an inner periphery of the annular chamber. The vertical annular chamber of the inlet diffuser has a larger diameter than the inlet pipe. The vertical baffles are mounted circumferentially along an inner periphery of the annular chamber. The plurality of sieve
25 plates is a combination of different sieve plates disposed at multiple levels with respect to one
another.
The following paragraphs describe the present disclosure with reference to Figures 1 to 5. In the
figures the same element or elements which have same functions are indicated by the same
30 reference signs.
7

Now referring to the figures, in which Figure 1 is an exemplary embodiment of the present
disclosure, there is provided an improved down-flow fixed bed reactor. As shown in Figures 1 and
2, the down-flow fixed bed reactor (100) comprises a housing (1) having a hollow internal space
(1a) for accommodating the various components of the fixed bed reactor. In an embodiment, the
5 housing (1) has a generally cylindrical configuration with a dome-shaped upper region. However,
it may be understood by a person skilled in the art that the shape and dimensional configuration of the housing may vary depending on the type of application, requirement of the user/manufacturer etc. The housing (1) comprises an opening being formed centrally in the dome to receive a fluid from an inlet pipe (2). The inlet pipe (2) is connected with the housing (1) at the opening to define
10 an inlet (101) of the down flow reactor (100). The inlet pipe (2) is generally disposed horizontally
and is therefore connected with the opening of the housing (1) by a connecting means such as a 90o elbow so as to feed an inlet fluid perpendicularly along a vertical axis XX. inlet diffuser (3) located in the hollow internal space (1a) of the housing (1) at the inlet (101). The inlet diffuser (3) is a device for decreasing angular and radial asymmetries of the inlet fluid, thereby achieving
15 uniform distribution of the inlet fluid inside the housing (1). The inlet diffuser comprises an annular
chamber (3a) being mounted concentrically in the inlet (101). The annular chamber (3a) comprises a hollow internal section defined between an upper end and a lower end so as to allow the inlet fluid to pass therethrough. A fluid inlet (A) is formed upwardly at the upper end of the annular chamber (3a) towards the inlet (101) of the down flow reactor (100). A fluid outlet (B) is formed
20 downwardly at the lower end of the annular chamber (3a). In a non-limiting embodiment, the
annular chamber (3a) of the inlet diffuser (3) has a larger diameter than the inlet pipe (2). A plurality of sieve plates (3b) may be mounted below the fluid outlet (B). Located below the inlet diffuser (3) is a distributer tray (4) which is configured to allow the inlet fluid from the inlet diffuser (3) to pass through. The distributor plate (4) is adapted to distribute the fluid from the inlet diffuser
25 (3) evenly over a catalyst bed (5) of the down-flow reactor (100). In one embodiment, the shape
and configuration of the distributor plate (4) is identical with the dimensional configuration of the catalyst bed (5). There may be provided some other elements like inert balls in the housing (1) depending on the nature and type of the refinement process. An outlet (not shown) may be provided below the catalyst bed to provide exit to the fluid in the down-flow fluid reactor (100).
30
8

Referring to Figures 2 and 3, the inlet diffuser (3) comprises a plurality of vertical baffles (6) to
impart uniform discharge to the inlet fluid passing through the annular chamber (3a) thereby
minimizing flow asymmetry and breaking fluid momentum in a vertically downward direction and
enhance the fluid mixing. In an embodiment, the baffles (6) have a generally rectangular
5 configuration. The baffles (6) are located equidistant from one another circumferentially along an
inner periphery of the annular chamber (3a). The inlet diffuser (3) further comprises the plurality of sieve plates (3b) disposed downwardly of the fluid outlet (B). During operation of the down-flow reactor, the plurality of sieve plates (3b) is configured to further uniformly distribute the fluids exiting the annular chamber (3a).
10
In one embodiment, as shown in Figures 4, there may be provided a splash plate (7) at the inlet (A) of the annular chamber (3a). The splash plate (7) may be mounting along a horizontal plane perpendicular to the vertical axis XX. The splash plate (7) has a generally circular configuration so as to be mounted concentrically in the annular chamber (3a). In the mounted condition, the
15 splash plate (7) is configured to resist the flow of the inlet fluid from the inlet pipe (2) and evenly
distribute the inlet fluid radially towards the inner periphery of the annular chamber (3a), thereby breaking the momentum of the inlet fluid to prevent high velocity erosion of the shell, internals, or solids bed of the down-flow reactor (100). In an embodiment, as shown in Figure 4, the splash plate (7) comprises a central aperture (7a) to allow at least a part of the inlet fluid from the inlet
20 pipe (2) to pass therethrough vertically downwards.
when the inlet fluid is fed into the inlet diffuser (3), the splash plate (7) diverts only a part of the inlet fluid towards the inner periphery of the annular chamber (3a). This results in even distribution of the inlet fluid in the annular chamber (3a). 25
List of reference numerals:

100 Improved Down-Flow Reactor
101 Inlet of the Improved Down-Flow Reactor
1 Housing
1a Hollow Internal Space of Housing
2 Inlet Pipe
3 Inlet Diffuser
9

3a Annular Chamber of the Inlet Diffuser
3b Plurality of Sieve Plates of the Inlet Diffuser
4 Distributor Tray
5 Catalyst Bed
6 Plurality of Baffles
7 Splash Plate
7a Aperture of the Splash Plate
A Fluid Inlet of the Annular Chamber
B Fluid Outlet of the Annular Chamber
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill
in the art can translate from the plural to the singular and/or from the singular to the plural as is
5 appropriate to the context and/or application. The various singular/plural permutations may be
expressly set forth herein for sake of clarity.
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
10 (e.g., the term “having” should be interpreted as “having at least,” 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
15 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
20 “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). It will be further
10

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."
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.

WE CLAIM

A novel gas-liquid inlet diffuser for down flow reactor comprising;
an inlet pipe (2) being configured with the housing (1) to define an inlet (101) of the down-flow reactor (100);
an inlet diffuser (3) located in the hollow internal space (la) of the housing (1) at the inlet (101); wherein the inlet diffuser (3) comprises;
an annular chamber (3a) having a fluid inlet (A) formed upwardly towards the inlet (101) of the down-flow reactor (100) and a fluid outlet (B) formed downwardly; and a plurality of vertical baffles (6) to impart uniform discharge to a fluid exiting the annular chamber (3a) thereby minimizing flow asymmetry and breaking fluid momentum in a vertically downward direction;
a plurality of sieve plates (3b) disposed downwardly of the fluid outlet (B); the plurality of sieve plates (3b) being configured to uniformly distribute the fluids exiting the annular chamber (3a);
a distributor tray (4) being configured below the inlet diffuser (1) in a region above a catalyst bed (5) of the down-flow reactor (100).
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claim 1, wherein the inlet pipe (2) is connected with the housing by means of a 90° elbow so as to feed the fluid perpendicularly along a vertical axis XX.
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claim 1, wherein a splash plate (7) is mounted horizontally at the fluid inlet (A) of the annular chamber (3a); the splash plate (7) being configured to resist the flow of the fluid from the inlet pipe (2) and evenly distribute the fluid in the inlet diffuser (3).

The novel gas-liquid inlet diffuser for down flow reactor as claimed in claims 1 and 3, wherein the splash plate (7) comprises a central aperture (7a) to allow at least a part of the fluid from the inlet pipe (2) to pass therethrough.
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claims 1 and 3, wherein the splash plate (7) is configured to radially divert at least a part of the fluid from the inlet pipe (3) towards an inner periphery of the annular chamber (3 a).
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claim 1, wherein the annular chamber (3 a) of the inlet diffuser (3) has a larger diameter than the inlet pipe
(2).
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claim 1, wherein the baffles (6) are mounted circumferentially along an inner periphery of the annular chamber (3a).
The novel gas-liquid inlet diffuser for down flow reactor as claimed in claim 1, wherein the plurality of sieve plates (3b) is a combination of different sieve plates disposed at multiple levels with respect to one another.