This invention relates to Deduster System at Air Quenching Chamber
(AQC) boiler to prevent particle erosion and reduce pressure drop of waste heat recovery system (WHRS) in Cement Kiln. The De-duster is placed before the Air Quenching Chamber Boiler.
BACKGROUND OF THE INVENTION:
[002] Background description includes information that may be useful in
understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] The Air Quenching Chamber (AQC) boilers of cement kiln are one of
the biggest steam generation facilities using waste heat in RAS location. These boilers utilize the waste heat from clinker cooler for steam generation and further for power generation. The gases from cooler are supplied along with clinker dust particles to the boiler via duct due to high velocity of gas from cooler (20-22 m/s). It was observed that the concentration of particles is in between 90 to 100 mg/Nm3.
[004] The nature of clinker dust particles is abrasive resulting in erosion of
boiler inner surface. Also the pressure drop in AQC boiler inlet duct is high in range of 30 to 35 mmWC. The high pressure drop consumes more power to draw gas flow from the cooler up to boiler via the duct.

[005] Various studies were carried out to explore the technology for particle
separation from gas but due to high temperature and bulk loading no technologies such as Electrostatic precipitator (ESP) or Bag filters etc. are suitable for purpose. The ESP/Bag filter is applicable upto 150 degree centigrade, whereas the clinker cooler is having temperature of more than 500 degree centigrade.
[006] On basis of detail study it was concluded that conceptually there are two
effective methods as follows which can be used for dust separation from gas.
1. Cyclone Separator.
2. Gas velocity reduction with change in particle momentum.
[007] Thereafter, advance computational fluid dynamics for best design selection was adopted.
Cyclone Separator
[008] The cyclone separators are very known and efficient technology for
particle separation from gas but on other hand it is highly energy consuming affair also due to high pressure drop.
[009] First modeling in CFD is run for cyclone separator installation at boiler
inlet.
[0010] Now, reference may be made to Figure l.In CFD simulation of cyclone
model, the separation is achieved as 75% but the pressure drop from clinker cooler tap off to boiler inlet (across Cyclone seperator) is obtained as 135 mmWC , whereas the installed duct pressure drop was only 35 mmWC. The idea was dropped due to very high pressure drop at boiler inlet section.

[0011] In view of the above disadvantages, the present invention has been
devised which can address shortcomings of the prior art and serve the purpose effectively. The instant invention is based on the principle of Gas velocity reduction and change in particle momentum by change in flow direction.
OBJECTS OF THE INVENTION:
[0012] An object of the invention is to provide Deduster System at AQC boiler
to prevent particle erosion and reduce pressure drop of WHRS in Cement Kiln.
[0013] Another object of the invention is to provide Deduster System at AQC
boiler to prevent particle erosion and reduce pressure drop of WHRS in Cement Kiln, which overcomes the drawbacks of Erosion in boiler and Pressure Drop Reduction.
[0014] Still another object of the invention is to provide Deduster System at
AQC boiler to prevent particle erosion and reduce pressure drop of WHRS in Cement Kiln, which is simple in construction and efficient.
[0015] These and other objects and advantages of the present invention will be
apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION:
[0016] One or more drawbacks of conventional systems and process are
overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments

and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[0017] To overcome the problem of particle erosion and pressure drop
reduction it was proposed to install a de-duster chamber at AQC boiler inlet by increase in flow area and change in particle momentum.
[0018] According to this invention, there is provided Deduster
System/chamber at AQC boiler to prevent particle erosion and reduce pressure drop of waste heat recovery system (WHRS) in Cement Kiln comprising a singly structured hollow chamber [1] with area expansion from bottom to top, which is placed between clinker cooler [2] and Air Quenching Chamber Boiler (AQC) [3] wherein said chamber [1] includes a gas inlet [101] in flow communication with the clinker cooler [2] gas outlet, in which the inlet [101] houses a plurality of baffles [102], the upper portion of the gas inlet [101] constituting first part [104] is expanded with respect to the gas inlet [101] so as to reduce the velocity; above the first part [104], second part [106] is located accommodating multiple baffles [107] and is expanded with respect to the first part [104] that the velocity of gas is further reduced; third part [109] is positioned above the second part [106] and is expanded with respect to the second part [106]; wherein the inlet [101] , first part [104], second part [106] and third part [109] provided on one side of the chamber [1] are in flow communication with the other side of chamber including fourth part [110] containing multitude of baffles [111].
[0019] Installation of de-duster chamber at AQC boiler inlet by increase in flow
area & change in particle momentum resulted in separation of around 65% clinker dust particle up to 200 microns before entering into boiler and the pressure drop of gas is getting reduced by 20 mmWC.

[0020] The main inventive features of the invention have been indicated in the
principal claim and subsidiary features of the invention have been depicted in the dependent claims.
[0021] Various objects, features, aspects, and advantages of the inventive
subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[0022] It is to be understood that the aspects and embodiments of the disclosure
described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[0023] The foregoing summary is illustrative only and is not intended to be in
any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0024] The illustrated embodiments of the subject matter will be best
understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-
Figure 1 shows: CFD for cyclone separator installation at boiler inlet.
Figure 2 shows: installation of Deduster chamber/system of the present invention
between cooler and AQC boiler.

Figure 3 shows: Front elevation of the Deduster chamber/system according to the
present invention.
Figure 4 shows: Isometric view of the Deduster chamber/system according to the
present invention.
Figure 5A shows: Dust Streamlines of the invention.
Figure 5B shows: Velocity vectors of the invention.
Figure 5C shows: Velocity contours of the invention.
Figure 5D shows: Contours of particle volume fraction of the invention.
[0025] The figures depict embodiments of the disclosure for purposes of
illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DEATIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF THE PREFERRED EMBODIMENTS:
[0026] 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.
[0027] This invention makes a disclosure regarding a technology pertaining to
an invention directing to Deduster System/chamber at Air Quenching Chamber (AQC) boiler to prevent particle erosion and reduce pressure drop of waste heat recovery system (WHRS) in Cement Kiln.

[0028] The carryover of clinker dust particles along with gas is due to high
escape velocity of gas from cooler (20-22 m/s). The proposed invention has been designed on basis of velocity reduction and change in particle momentum by change in flow direction.
[0029] The deduster system/chamber [1] is placed between cooler [2] on one
side and air quenching chamber boiler [3] on other side as shown in the figure 2. The cooler is used to cool the clinker from cement kiln. The hot gases generated during cooling of the clinker is taken from the cooler to the boiler via chamber [1] of the instant invention for steam generation.
[0030] Now, reference may be made to Figure 3 and 4 illustrating the de
dusting chamber of the instant invention. Here, clinker cooler [2] outlet is in flow communication with gas inlet [101] of the de duster chamber [1]. The gas inlet which is substantially a rectilinear tube houses a plurality of baffles [102] placed at a gap from each other. The baffles [102] are angled plates in this particular embodiment. Further, its function is equal distribution of the hot gas and also guiding the gas in the required upward direction. The profile of said gas inlet [101] and also of other parts of the chamber are designed so as to avoid fouling with adjacent parts of the cooler, boiler etc. Further, the side [103] of the inlet [101] facing towards the chamber [1] itself is provided with slope, which facilitates back flow of particles into the cooler [2] after separation from the gas. A Damper assembly can be provided adjacent to the baffles [102] in order to isolate the chamber during maintenance/shut down/boiler isolation.
[0031] The upper portion of the gas inlet [101] constituting first part [104] is
further expanded with respect to the gas inlet [101] so as to reduce the velocity. The area expansion of the upper portion is accomplished by providing side face [105] at an

obtuse angle with respect to the inlet side face [103]. The area expansion is gradual otherwise recirculation of flow starts, which needs to be avoided.
[0032] Above the first part [104], second part [106] is located accommodating
multiple baffles [107]. Said baffles [107] are plates disposed at a distance from each other. The same is meant for uniform distribution of gas and to guide the gas flow till the top of the chamber [1]. The second part [106] is further expanded with respect to the first part [104], so that the velocity of gas can be further reduced. The side face [108] of the second part [106] is also sloped to help back flow of particles into the cooler [2] after separation of the same from the gas. This side face [108] can be fitted with inspection door for inspection of said chamber upon requirement.
[0033] Thereafter, third part [109] is provided to be positioned just above the
second part [106] in flow communication to each other. The third part [109] is further expanded area wise with respect to the second part [106] as best seen in the figure.
[0034] Thus, area of the chamber [1] is expanded from bottom to top.
[0035] The gas flow includes clinker dust particles. With the reduction in the
velocity of flow, the escape velocity of the particles gets reduced and as a result fall back into the cooler. Further, said velocity reduction leads to pressure drop reduction at the inlet of the boiler, thereby consuming less power to draw hot gas upto the boiler via said chamber [1].
[0036] The aforesaid first part [104], second part [106], third part [109] and
inlet [101] provided on one side of the chamber [1] deal with heavy particles of flow. Here, the heavy particles are separated from the gas mainly due to velocity reduction. The area/volume of this side is comparatively more as compared to the other side of the chamber divided by momentum change plane Y-Z.
[0037] The other side includes fourth part [110] containing multitude of the
baffles [111]. The baffles [111] are disposed maintaining a gap there between, which

uniformly distribute the gas and guide the same downwards in the required direction towards exit part [113] including collection hopper[112].
[0038] The shape of the baffles may vary according to the shape of the
chamber [1]. The gap between the baffles in the inlet [101], second part [106] and fourth part [110] may be same or different. The gap is determined according to the input gas parameters for example velocity of flow, temperature etc. However, the gap is such that it uniformly distributes the gas. The placement/alignment of the baffles is such that, the same directs the gas flow in the required direction inside the chamber [1].
[0039] The momentum change plane Y-Z helps in changing momentum of the
particles. Thus once the gas flow crosses the momentum change plane Y-Z, the momentum of the particles undergoes changes by directional changes of the gas flow from upwards towards downwards.
[0040] The inner side face [114] of exit part [113] of the chamber [1] is devised
with a sharp slope forming sharp turndown, which imparts jerk to the particles so as to direct the same into the hopper [112] at the bottom. The hopper discharges the accumulated particles by means of conveyor system connected thereto. There is provision of at least two outlets [115] on the side of the hopper [112]. The outlets [115] discharging hot gas are in flow communication with the inlets of the boiler.
[0041] The other side deals with lighter particles comparatively. Here, the
lighter particles are separated from the gas mainly due to momentum / directional change of the same.
[0042] The chamber can be made of material such as mild steel (MS) sheet with
inner refractory linear [so as to bear the high temperature] without restricting scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are understood to be within purview of the invention. Said chamber is a single hollow structure.
[0043] The chamber [1] discussed above is exemplary. Hence, it does not have
specific shape as illustrated in figure 3 and 4. The same varies according to the volume

of gas to be handled and available space. The chamber can be expanded vertically or horizontally according to availability of space so as to serve the purpose.
Advantages of Invention
Separation of around 65% clinker dust particle up to 200 microns before entering into boiler.
De-Duster is suitable for separation of dust particles from clinker cooler outlet gas without any pressure drop and auxiliary power consumption like Electro Static Precipitator.
- Reduction in the erosion due to clinker dust particle by reducing the dust load from 90 to 40 gm/Nm3 along with velocity from 22 to 11 m/s.
Reduction in the boiler inlet duct pressure drop from 32 mmWc to 12 mmWC.
Achievement of De-Duster efficiency up to 65 %.
WORKING OF INVENTION:
Gases from cement plant clinker cooler along with clinker dust particles entered to de-duster chamber through set of baffles plates [102].
The objective of baffles [102] is to create a smooth passage for gases entered into de-duster as well as uniform velocity contour.
After passing through baffles [102] arrangement, the cross sectional area started to increase. The baffles [107] are designed such that they can up lift the gases to the top most part of de-duster chamber where particle velocity will further reduce significantly & heavy particles above 1 mm size will separate out from gases & fall back to cooler. Light particle separation takes place in other side because of the theory of change in the direction by change in particle momentum.
The momentum change starts from starting of baffles [111] arrangement where 2 set of curved guide vanes turn the gas back to downward direction towards hopper & entered into boiler section by 90° side entry.

>. Due to sudden momentum change & low velocity zone in hopper the fine particles will
be separated into de-duster hopper. '. The clean gases exit from de-duster chamber from dual outlet [115] into boiler.
The complete de-dusting process does not use any external or additional energy
consumption for particle separation from gases.
TEST RESULT:

LAR UOM (+) 2.36 mm (+) 1.00 mm 0.50 mm (+) 212 |im (+) 180 |im (+) 150 |im (+) 90 |im (+) 75 |im (+) 45 |im () 45 |im EROSIVE PARTICLES FINE PARTICLES OVERA
R INLET % 0.43 6.28 63.8 24.6 1.52 0.56 2.34 0.49 70.5 29.5 100.0
R OUTLET % 0.01 0.13 12.50 19.70 1.34 0.54 2.28 0.48 12.64 24.33 36.97
ON IY % 98.2 97.9 80.4 19.8 11.9 3.2 2.7 2.2 82.1 17.4 63.0
Reference may be made to Figure 5A - 5D.
[0044] Figure 5A indicates Dust Stream Lines:- In this CFD analysis,
the velocity of individual size particles without gases (<90 microns to 2.36 mm) inside the deduster was checked.
[0045] Figure 5B indicates Velocity Vectors:- In this CFD analysis,
the direction of velocity for individual size particles without gases (<90 microns to 2.36 mm) inside the deduster was checked.
[0046] Figure 5C indicates Velocity Contours:- In this CFD analysis,
the velocity of individual size particles along with gases (<90 microns to 2.36 mm) inside the deduster was checked.

[0047] Figure 5D indicates Contours of Particle Volume Fraction:- In this
CFD Analysis, the amount of specific particle or volume of particles along with gases for every individual size of <90 microns to 2.36 mm inside deduster was checked.
[0048] The above reflects Successful and excellent results of De-duster before
AQC boiler.
[0049] Each of the appended claims defines a separate invention, which for
infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0050] Groupings of alternative elements or embodiments of the invention
disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.
[0051] It will be understood by those within the art that, in general, terms used
herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to,"

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

the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A orB" will be understood to include the possibilities of "A" or "B" or "A and B".
[0052] The above description does not provide specific details of manufacture
or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0053] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0054] The claims, as originally presented and as they may be amended,
encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0055] 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:

1. Deduster System/chamber at AQC boiler to prevent particle erosion and reduce pressure drop of waste heat recovery system (WHRS) in Cement Kiln comprising a singly structured hollow chamber [1] with area expansion from bottom to top, which is placed between clinker cooler [2] and Air Quenching Chamber Boiler (AQC) [3] wherein said chamber [1] includes a gas inlet [101] in flow communication with the clinker cooler [2] gas outlet, in which the inlet [101] houses a plurality of baffles [102], the upper portion of the gas inlet [101] constituting first part [104] is expanded with respect to the gas inlet [101] so as to reduce the velocity; above the first part [104], second part [106] is located accommodating multiple baffles [107] and is expanded with respect to the first part [104] that the velocity of gas is further reduced; third part [109] is positioned above the second part [106] and is expanded with respect to the second part [106]; wherein the inlet [101] , first part [104], second part [106] and third part [109] provided on one side of the chamber [1] are in flow communication with the other side of chamber including fourth part [110] containing multitude of baffles [111].
2. The deduster System/chamber as claimed in claim 1, wherein the inlet [101], side face [103] of which facing towards the chamber [1] itself is provided with slope, which facilitates back flow of particles into the cooler [2] after separation of the particles from the gas.
3. The deduster System/chamber as claimed in claims 1-2, wherein a Damper assembly may be provided adjacent to the baffles [102] in order to isolate the chamber [1] during maintenance/shut down/boiler isolation.

4. The deduster System/chamber as claimed in claims 1-3, wherein the side face [108] of the second part [106] is provided with a slope to facilitate back flow of particles into the cooler [2] after separation of the same from the gas, in which the side face [108] may be fitted with inspection door for inspection of said chamber upon requirement.
5. The Deduster System/chamber as claimed in claims 1-4, wherein the baffles [102,107] direct gas flow upwards and the baffles [111] direct the gas downwards towards exit part [113] including collection hopper [112] for collecting the particles.
6. The deduster system/chamber as claimed in claims 1-5, wherein said baffles [102,107,111] are plates disposed at a distance from each other, shape of which may vary according to the shape of the chamber [1], in which the gap between the baffles in the inlet [101], second part [106] and fourth part [110] may be same or different, which is determined according to the input gas parameters including velocity of flow, temperature, wherein the gap is such that it uniformly distributes the gas, and the alignment of the baffles is such that, the same directs the gas flow in the required upward/downward direction inside the chamber [1].
7. The deduster system/chamber as claimed in claims 1-6, wherein the inner side face [114] of exit part [113] of the chamber [1] is devised with a sharp slope forming sharp turndown, which imparts jerk to the particles so as to direct the same into the hopper [112] at the bottom, in which at least two outlets [115] are provided on the side of the hopper [112] for discharging hot gas, wherein the outlets [115] are in flow communication with the inlets of the boiler.

8. The deduster system/chamber as claimed in claims 1-7, wherein the first part [104], second part [106], third part [109] and inlet [101] provided on one side of the chamber [1] deal with heavy particles of flow, which are separated from the gas due to velocity reduction.
9. The deduster system/chamber as claimed in claims 1-7, wherein the other side deals with lighter particles, which are separated from the gas due to momentum / directional change of the particles.
10. The deduster system/chamber as claimed in claims 1-9, wherein the chamber is made of material including mild steel (MS) sheet with inner refractory linear so as to bear the high temperature.