 The present disclosure relates to the field of optical fibre and in
particular, relates to a method of sintering glass preform with reduced helium
consumption.
10
BACKGROUND
 With the advancement of science and technology, various modern
technologies are being employed for communication purposes. One of the most
15 important modern communication technologies is optical fibre. In general,
optical fibre is a flexible, transparent fibre made by drawing glass (silica) or
plastic to a diameter slightly thicker than that of a human hair. The glass optical
fibre is made from glass “preform”. This preform is sintered soot deposited on
bait rod. The sintering of the soot preform produces a dense and non-porous glass
20 preform. Conventionally, sintering of the preform is performed using high
consumption of helium. However, high consumption of helium increases over all
cost of the manufacturing process as helium is costlier than other inert gases like
argon and nitrogen. In addition, helium consumption in sintering is 390 to 430
times volume of soot at existing level. Further, helium is non-renewable natural
25 resource and is depleting with time. Furthermore, cost and supply of helium is
controlled by foreign countries which makes us dependent.
 In light of the above stated discussion, there is a need of an advanced
method for sintering of a glass preform that overcomes the above stated
30 drawbacks.
SUMMARY
3 / 23
5  In an aspect, the present disclosure provides a method for sintering of a
glass preform with reduced helium gas consumption. The method includes a first
step to perform dehydration of the soot preform inside a dehydration module. In
addition, the method includes a second step to perform down-feeding of the glass
preform inside a sintering furnace. Further, the method includes a third step to
10 perform sintering of the glass preform inside the sintering furnace. Furthermore,
the method includes a fourth step to move the glass preform in upward motion.
Also, the glass preform undergoes dehydration for time period in range of about
20 minutes to 120 minutes. Dehydration of the glass preform is performed in
presence of chlorine gas or mixture of chlorine and other inert gases. Also, down15 feeding of the glass preform is done for about 10 minutes. Also, sintering of the
glass preform is done in one or more sintering stages. The one or more sintering
stages include but may not be limited to first sintering stage, second sintering
stage, and third sintering stage and so on. Also, the glass preform undergoes
upward motion for about 1 minute. Also, the glass preform undergoes re20 sintering for about 10 to 25 minutes.
 In an embodiment of the present disclosure, the dehydration module is
utilized to perform dehydration of the glass preform in presence of helium gas.
25  In an embodiment of the present disclosure, the sintering furnace is
utilized to perform sintering of the glass preform in presence of helium gas.
 In an embodiment of the present disclosure, rate of flow of helium gas
during dehydration of the glass preform is about 5 to 40 standard liter per minute
30 for time period in range of about 20 minutes to 120 minutes.
 In an embodiment of the present disclosure, the glass preform is kept
inside the sintering furnace at temperature of about 1200° to 1400° Celsius for
about 20 to 60 mins.
4 / 23
5
 In an embodiment of the present disclosure, the glass preform is moving
in the sintering furnace for about 5 to 10 minutes.
 In an embodiment of the present disclosure, the glass preform undergoes
10 first sintering stage for about 120 to 160 minutes.
 In an embodiment of the present disclosure, the glass preform is fed with
helium gas during dehydration and sintering in semi-continuous way.
15  In an embodiment of the present disclosure, the glass preform undergoes
second sintering stage for about 100 to 150 minutes.
 In an embodiment of the present disclosure, the glass preform undergoes
third sintering stage for about 80 to 100 minutes.
20
STATEMENT OF THE DISCLOSURE
 The present disclosure provides a method for sintering of a glass preform
with reduced helium gas consumption. The method includes a first step to
25 perform dehydration of the glass preform inside a dehydration module. In
addition, the method includes a second step to perform down-feeding of the glass
preform inside a sintering furnace. Further, the method includes a third step to
perform sintering of the glass preform inside the sintering furnace. Furthermore,
the method includes a fourth step to move the glass preform in upward motion.
30 Moreover, the method includes a fifth step to perform re-sintering of the glass
preform inside the sintering furnace. Also, the glass preform undergoes
dehydration for time period in range of about 20 minutes to 120 minutes.
Dehydration of the glass preform is performed in presence of mixture of chlorine
and inert gas. Also, down-feeding of the glass preform is done for about 10
5 / 23
5 minutes. Also, sintering of the glass preform is done in one or more sintering
stages. The one or more sintering stages include but may not be limited to first
sintering stage, second sintering stage, and third sintering stage and so on. Also,
the glass preform undergoes upward motion for about 1 minute. Also, the glass
preform undergoes re-sintering for about 10 to 25 minutes.
10
OBJECT OF THE DISCLOSURE
 A primary object of the present disclosure is to provide a method for
sintering of a glass preform with reduced helium gas consumption.
15
 Another object of the present disclosure is to provide the glass preform
with reduced cost.
 Yet another object of the present disclosure is to provide the method to
20 reduce helium gas consumption by 30 percent without affecting any optical or
other parameter of the fiber obtained from glass preform processed in this way.
BRIEF DESCRIPTION OF THE DRAWINGS
25  Having thus described the invention in general terms, reference now be
made to the accompanying drawings, which are not necessarily drawn to scale,
and wherein:
 FIG. 1 illustrates a general overview of a system for sintering of a glass
30 preform, in accordance with various embodiments of the present disclosure;
 FIG. 2 illustrates a flowchart describing a method for sintering of the
glass preform, in accordance with various embodiments of the present disclosure;
6 / 23
5
 FIG. 3 illustrates a graph for flow pattern of helium gas consumption
during dehydration and sintering of the glass preform, in accordance with an
embodiment of the present disclosure;
10  FIG. 4 illustrates the graph for flow pattern of helium gas consumption
during dehydration and sintering of the glass preform, in accordance with another
embodiment of the present disclosure;
 FIG. 5 illustrates the graph for flow pattern of helium gas consumption
15 during dehydration and sintering of the glass preform, in accordance with yet
another embodiment of the present disclosure;
 FIG. 6 illustrates the graph for flow pattern of helium gas consumption
during dehydration and sintering of the glass preform, in accordance with yet
20 another embodiment of the present disclosure;
 FIG. 7 illustrates the graph for flow pattern of helium gas consumption
during dehydration and sintering of the glass preform, in accordance with yet
another embodiment of the present disclosure; and
25
 FIG. 8 illustrates the graph for flow pattern of helium gas consumption
during dehydration and sintering of the glass preform, in accordance with yet
another embodiment of the present disclosure.
30  It should be noted that the accompanying figures are intended to present
illustrations of exemplary embodiments of the present disclosure. These figures
are not intended to limit the scope of the present disclosure. It should also be
noted that accompanying figures are not necessarily drawn to scale.
7 / 23
5 DETAILED DESCRIPTION
 Reference will now be made in detail to selected embodiments of the
present disclosure in conjunction with accompanying figures. The embodiments
described herein are not intended to limit the scope of the disclosure, and the
10 present disclosure should not be construed as limited to the embodiments
described. This disclosure may be embodied in different forms without departing
from the scope and spirit of the disclosure. It should be understood that the
accompanying figures are intended and provided to illustrate embodiments of the
disclosure described below and are not necessarily drawn to scale. In the
15 drawings, like numbers refer to like elements throughout, and thicknesses and
dimensions of some components may be exaggerated for providing better clarity
and ease of understanding.
 It should be noted that the terms "first", "second", and the like, herein do
20 not denote any order, ranking, quantity, or importance, but rather are used to
distinguish one element from another. Further, the terms "a" and "an" herein do
not denote a limitation of quantity, but rather denote the presence of at least one
of the referenced item.
25  FIG. 1 illustrates a general overview of a system 100 for sintering of a
glass preform 102, in accordance with various embodiments of the present
disclosure. The system 100 includes the glass preform 102, a dehydration module
104, and a sintering furnace 106.
30  The system 100 includes the glass preform 102. In general, glass
preform is cylindrical body having core structure and cladding structure. In
addition, glass preform is material used for fabrication of optical fibres.
8 / 23
5  In an embodiment of the present disclosure, the glass preform 102 is
manufactured using OVD process. In general, OVD refers to outside vapor
deposition. In addition, outside vapor deposition (OVD) is process in which glass
preform is manufactured by depositing silica soot on surface of some target rod.
10  In another embodiment of the present disclosure, the glass preform 102 is
manufactured using VAD process. In general, VAD process refers to as vapor
axial deposition (VAD) process. In addition, vapor axial deposition process is
used to manufacture porous glass preform. Further, vapor axial deposition
process facilitates fabrication of porous glass preform by depositing fine glass
15 material onto end surface of starting material through flame hydrolysis.
Furthermore, starting material is pulled upward in axial direction and porous glass
preform is grown in the same direction. Moreover, starting material is volatile
organic compound that includes but may not be limited to SiCl4, GeCl4 and O2.
Also, porous glass preform is heated to manufacture transparent fibre preform.
20
 In yet another embodiment of the present disclosure, the glass preform
102 is manufactured using ACVD process. In general, ACVD process refers to
atmospheric chemical vapor deposition process.
25  In yet another embodiment of the present disclosure, the glass preform
102 is manufactured using PCVD process. In general, PCVD process refers to
plasma chemical vapor deposition process.
 In an embodiment of the present disclosure, the glass preform 102 is
30 manufactured by depositing silica soot over glass body. In general, silica soot is
powdery or flaky substance consists largely of amorphous carbon and produced
by incomplete burning of organic matter. In an example, glass body is mounted
on lathe. In addition, lathe is machine tool that rotates glass body about axis of
rotation to perform various operations. Further, various operations performed by
9 / 23
5 lathe are cutting, drilling, knurling, deformation, and the like. Furthermore, glass
body is placed on heat source and reacts with gases.
 In an example, the glass preform 102 is manufactured by depositing
silica soot over glass body. In addition, silica soot deposited over glass body is
10 densified above glass transition temperature. In another example, the glass
preform 102 is manufactured in non-vacuum environment. In addition, nonvacuum environment consolidates silica soot over glass body in presence of inert
gases with high thermal conductivity. Further, inert gases include helium, argon
and the like. Furthermore, inert gases are used for thermal diffusion inside porous
15 soot surface.
 The system 100 includes the dehydration module 104. The dehydration
module 104 is utilized to perform dehydration of the glass preform 102. In
general, dehydration corresponds to drying of glass preform. In addition,
20 dehydration removes water and other impurities from glass preform. Further,
dehydration refers to removal of OH ion content from glass preform. In an
embodiment of the present disclosure, dehydration of the glass preform 102 is
performed inside the dehydration module 104 in presence of chlorine or mixture
of chlorine and inert gas. In another embodiment of the present disclosure,
25 dehydration of the glass preform 102 is performed inside the dehydration module
104 in presence of argon gas. In yet another embodiment of the present
disclosure, dehydration of the glass preform 102 is performed inside the
dehydration module 104 in presence of any suitable gaseous atmosphere.
30  The system 100 includes the sintering furnace 106. The sintering furnace
106 is utilized to perform sintering of the glass preform 102. Further, sintering of
the glass preform 102 causes shrinkage during glass transition temperature.
Furthermore, sintering reduces porosity of the glass preform 102. In addition, the
10 / 23
5 glass preform 102 undergoes down-feeding into the sintering furnace 106. In an
embodiment of the present disclosure, the down-feeding of the glass preform 102
into the sintering furnace 106 is performed in presence of helium gas. The downfeeding of the glass preform 102 into the sintering furnace 106 facilitates sintering
of the glass preform 102. In an embodiment of the present disclosure, the
10 sintering furnace 106 receives helium gas at flow rate in range of about 20
standard litre per minute to 40 standard litre per minute during sintering of the
glass preform 102. In another embodiment of the present disclosure, range of
flow rate of helium gas in the sintering furnace 106 may vary. In another
embodiment of the present disclosure, consumption of helium gas during
15 sintering of the glass preform 102 may vary. In an embodiment of the present
disclosure, flow of helium gas inside the sintering furnace 106 is done in semicontinuous way.
 FIG. 2 illustrates a flow chart 200 describing steps to manufacture the
20 glass preform 102, in accordance with various embodiments of the present
disclosure. The flow chart 200 initiates at step 202. Following step 202, at step
204, dehydration of the glass preform 102 is performed inside the dehydration
module 104. In an embodiment of the present disclosure, the glass preform 102
undergoes dehydration for time period in range of about 20 minutes to 120
25 minutes. In another embodiment of the present disclosure, time period for
dehydration of the glass preform 102 may vary. In an embodiment of the present
disclosure, rate of flow of helium gas during dehydration of the glass preform 102
is about 35 standard litre per minute for time period in range of about 20 minutes
to 40 minutes. In another embodiment of the present disclosure, rate of flow of
30 helium gas during dehydration of the glass preform 102 may vary.
 In an embodiment of the present disclosure, dehydration of the glass
preform 102 is performed in presence of helium gas. In another embodiment of
11 / 23
5 the present disclosure, dehydration of the glass preform 102 is performed in
presence of any suitable inert gas.
 At step 206, the glass preform 102 undergoes down-feeding into the
sintering furnace 106. In an embodiment of the present disclosure, time taken by
10 the glass preform 102 to reach the sintering furnace 106 is about 10 minutes. In
another embodiment of the present disclosure, time taken by the glass preform
102 to reach the sintering furnace 106 may vary. In an embodiment of the present
disclosure, the glass preform 102 undergoes down-feeding inside the sintering
furnace 106. In an embodiment of the present disclosure, rate of flow of helium
15 gas during down-feeding of the glass preform 102 is about 35 standard litre per
minute. In another embodiment of the present disclosure, rate of flow of helium
gas during down-feeding of the glass preform 102 may vary.
 In an embodiment of the present disclosure, the glass preform 102 is kept
20 inside the sintering furnace 106 at temperature of about 1400° Celsius. In another
embodiment of the present disclosure, temperature of the glass preform 102 inside
sintering furnace 106 may vary. In an embodiment of the present disclosure, the
glass preform 102 is kept at temperature 1400° Celsius for time period of about
40 minutes. In another embodiment of the present disclosure, time to maintain
25 temperature of the glass preform 102 at 1400° Celsius may vary. In an
embodiment of the present disclosure, the glass preform 102 is feed with helium
gas at temperature 1400° Celsius. In an embodiment of the present disclosure,
rate of flow of helium gas towards the glass preform 102 at temperature 1400°
Celsius is about 25 to 40 standard liter per minute. In another embodiment of the
30 present disclosure, rate of flow of helium gas towards the glass preform 102 may
vary.
12 / 23
5  In an embodiment of the present disclosure, the glass preform 102 is
moving in the sintering furnace 106 for time period of about 5 to 10 minutes. In
another embodiment of the present disclosure, time period to move the glass
preform 102 in the sintering furnace 106 may vary. In an embodiment of the
present disclosure, the glass preform 102 moves inside the sintering furnace 106
10 in presence of helium gas
 At step 208, the glass preform 102 undergoes sintering inside the
sintering furnace 106. In an embodiment of the present disclosure, sintering of
the glass preform 102 is performed in one or more sintering stages. In an
15 embodiment of the present disclosure, the one or more sintering stages include
but may not be limited to first sintering stage, second sintering stage, and third
sintering stage. In an embodiment of the present disclosure, the glass preform
102 undergoes first sintering stage. In an embodiment of the present disclosure,
the glass preform 102 undergoes first sintering stage for time period of about 150
20 to 200 minutes. In another embodiment of the present disclosure, time period for
sintering of the glass preform 102 at first sintering stage may vary. In an
embodiment of the present disclosure, rate of flow of helium gas during first
sintering stage is about 25 to 40 standard liter per minute. In another embodiment
of the present disclosure, rate of flow of helium gas during first sintering stage
25 may vary.
 In an embodiment of the present disclosure, the glass preform 102
undergoes second sintering stage. In an embodiment of the present disclosure, the
glass preform 102 undergoes second sintering stage for time period of about
30 114.6 minutes. In another embodiment of the present disclosure, time period for
sintering the glass preform 102 during second sintering stage for may vary. In an
embodiment of the present disclosure, rate of flow of helium gas during second
sintering stage is about 35 standard litre per minute. In another embodiment of
13 / 23
5 the present disclosure, rate of flow of helium gas during second sintering stage
may vary.
 In an embodiment of the present disclosure, the glass preform 102
undergoes third sintering stage. In an embodiment of the present disclosure, the
10 glass preform 102 undergoes third sintering stage for time period of about 94.1
minutes. In another embodiment of the present disclosure, time period for
sintering of the glass preform 102 during third sintering stage may vary. In an
embodiment of the present disclosure, rate of flow of helium gas during third
sintering stage is about 35 standard litre per minute. In another embodiment of
15 the present disclosure, rate of flow of helium gas during third sintering stage may
vary.
 At step 210, the glass preform 102 undergoes upward motion after the
one or more sintering stages. In an embodiment of the present disclosure, the
20 glass preform 102 undergoes upward motion for time period of about 1 minute.
In another embodiment of the present disclosure, time period for upward motion
of the glass preform 102 may vary. In an embodiment of the present disclosure,
the glass preform 102 is feed with helium gas during upward motion. In an
embodiment of the present disclosure, rate of flow of helium during upward
25 motion is about 35 standard litre per minute. In another embodiment of the
present disclosure, rate of flow of helium gas during upward motion may vary.
 At step 212, the glass preform 102 undergoes re-sintering. In an
embodiment of the present disclosure, the glass preform 102 undergoes re30 sintering for time period of about 22.7 minutes. In another embodiment of the
present disclosure, time period for re-sintering of the glass preform 102 may vary.
In an embodiment of the present disclosure, rate of flow of helium gas during resintering of the glass preform 102 is about 35 standard litre per minute. In
14 / 23
5 another embodiment of the present disclosure, rate of flow of helium gas during
re-sintering of the glass preform 102 may vary. The flow chart terminates at step
214.
 FIG. 3 illustrates a graph 300 for flow pattern of helium gas
10 consumption during dehydration and sintering of the glass preform 102, in
accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 300 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
introduced in continuous way. In an embodiment of the present disclosure, rate
15 of flow of helium gas as shown in the graph 300 is about 25 standard litre per
minute for any particular time. In another embodiment of the present disclosure,
rate of flow of helium gas may vary for any particular time.
 FIG. 4 illustrates a graph 400 for flow pattern of helium gas
20 consumption during dehydration and sintering of the glass preform 102, in
accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 400 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
introduced in semi-continuous way. In an embodiment of the present disclosure,
25 flow of helium gas for time in between 0 seconds to 55 seconds is 25 standard
litre per minute. In addition, flow of helium gas is halt for time in between 55
seconds to 60 seconds as shown in the graph 400. Further, flow of helium gas for
time in between 60 seconds to 80 seconds is 25 standard litre per minute. In an
embodiment of the present disclosure, helium gas consumption in semi30 continuous way reduces overall consumption of helium gas during dehydration
and sintering of the glass preform 102.
15 / 23
5  FIG. 5 illustrates a graph 500 for flow pattern of helium gas
consumption during dehydration and sintering of the glass preform 102, in
accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 500 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
10 introduced in semi-continuous way. In an embodiment of the present disclosure,
flow of helium gas for time in between 0 seconds to 25 seconds is 25 standard
litre per minute. In addition, flow of helium gas is halt for time in between 25
seconds to 30 seconds as shown in the graph 400. Further, helium gas is reintroduced with flow of about 25 standard litre per minute for time in between 30
15 seconds to 55 seconds. Furthermore, flow of helium gas is halt for time in
between 55 seconds to 60 seconds. Moreover, helium gas is re-introduced for
time in between 60 seconds to 80 seconds with flow of 25 standard litre per
minute.
20  FIG. 6 illustrates a graph 600 for flow pattern of helium gas
consumption during dehydration and sintering of the glass preform 102, in
accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 600 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
25 introduced in non-continuous way. In an embodiment of the present disclosure,
flow of helium gas for time in between 0 seconds to 25 seconds is 25 standard
litre per minute. In addition, flow of helium gas is reduced to 12.5 standard litre
per minute for time in between 25 seconds to 30 seconds. Further, helium gas is
re-introduced with flow of about 25 standard litre per minute for time in between
30 30 seconds to 55 seconds. Furthermore, flow of helium gas is halt for time in
between 55 seconds to 60 seconds. Moreover, helium gas is re-introduced for
time in between 60 seconds to 80 seconds with flow of 25 standard litre per
minute. In an embodiment of the present disclosure, helium gas consumption in
16 / 23
5 non-continuous way reduces overall consumption of helium gas during
dehydration and sintering of the glass preform 102.
 FIG. 7 illustrates a graph 700 for flow pattern of helium gas
consumption during dehydration and sintering of the glass preform 102, in
10 accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 700 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
introduced in non-continuous way. In an embodiment of the present disclosure,
rate of flow of helium gas during dehydration and sintering of the glass preform
15 102 is defined by threshold value. In addition, threshold value for helium gas is
25 standard litre per minute. In an embodiment of the present disclosure, flow of
helium gas for time in between 0 seconds to 5 seconds is 6.25 standard litre per
minute. In an embodiment of the present disclosure, flow of helium gas for time
in between 5 seconds to 10 seconds is 12.5 standard litre per minute. In an
20 embodiment of the present disclosure, flow of helium gas for time in between 10
seconds to 15 seconds is 18.75 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 15 seconds to 20
seconds is 25 standard litre per minute.
25  In an embodiment of the present disclosure, flow of helium gas for time
in between 20 seconds to 25 seconds is 18.75 standard litre per minute. In an
embodiment of the present disclosure, flow of helium gas for time in between 25
seconds to 30 seconds is 12.5 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 30 seconds to 35
30 seconds is 6.25 standard litre per minute. In an embodiment of the present
disclosure, flow of helium gas for time in between 35 seconds to 40 seconds is 0
standard litre per minute.
17 / 23
5  In an embodiment of the present disclosure, flow of helium gas for time
in between 40 seconds to 45 seconds is 6.25 standard litre per minute. In an
embodiment of the present disclosure, flow of helium gas for time in between 45
seconds to 50 seconds is 12.5 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 50 seconds to 55
10 seconds is 18.75 standard litre per minute. In an embodiment of the present
disclosure, flow of helium gas for time in between 55 seconds to 60 seconds is 25
standard litre per minute.
 In an embodiment of the present disclosure, flow of helium gas for time
15 in between 60 seconds to 65 seconds is 18.75 standard litre per minute. In an
embodiment of the present disclosure, flow of helium gas for time in between 65
seconds to 70 seconds is 12.5 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 70 seconds to 75
seconds is 6.25 standard litre per minute. In an embodiment of the present
20 disclosure, flow of helium gas for time in between 75 seconds to 80 seconds is 0
standard litre per minute.
 FIG. 8 illustrates a graph 800 for flow pattern of helium gas
consumption during dehydration and sintering of the glass preform 102, in
25 accordance with an embodiment of the present disclosure. In an embodiment of
the present disclosure, the graph 800 describes flow pattern of helium gas during
dehydration and sintering of the glass preform 102. In addition, helium gas is
introduced in non-continuous way. In an embodiment of the present disclosure,
flow of helium gas for time in between 0 seconds to 5 seconds is 7 standard liter
30 per minute. In an embodiment of the present disclosure, flow of helium gas for
time in between 5 seconds to 10 seconds is 10 standard litre per minute. In an
embodiment of the present disclosure, flow of helium gas for time in between 10
seconds to 15 seconds is 12 standard litre per minute. In an embodiment of the
18 / 23
5 present disclosure, flow of helium gas for time in between 15 seconds to 20
seconds is 13 standard litre per minute.
 In an embodiment of the present disclosure, flow of helium gas for time
in between 20 seconds to 25 seconds is 13 standard litre per minute. In an
10 embodiment of the present disclosure, flow of helium gas for time in between 25
seconds to 30 seconds is 12 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 30 seconds to 35
seconds is 10 standard litre per minute. In an embodiment of the present
disclosure, flow of helium gas for time in between 35 seconds to 40 seconds is 7
15 standard litre per minute. In an embodiment of the present disclosure, flow of
helium gas for time in between 40 seconds to 45 seconds is 0 standard litre per
minute.
 In an embodiment of the present disclosure, flow of helium gas for time
20 in between 45 seconds to 50 seconds is 7 standard litre per minute. In an
embodiment of the present disclosure, flow of helium gas for time in between 50
seconds to 55 seconds is 10 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 55 seconds to 60
seconds is 12 standard litre per minute. In an embodiment of the present
25 disclosure, flow of helium gas for time in between 60 seconds to 65 seconds is 13
standard litre per minute.
 In an embodiment of the present disclosure, flow of helium gas for time
in between 65 seconds to 70 seconds is 13 standard litre per minute. In an
30 embodiment of the present disclosure, flow of helium gas for time in between 70
seconds to 75 seconds is 12 standard litre per minute. In an embodiment of the
present disclosure, flow of helium gas for time in between 75 seconds to 80
seconds is 10 standard litre per minute. In an embodiment of the present
19 / 23
5 disclosure, flow of helium gas for time in between 80 seconds to 85 seconds is 7
standard litre per minute. In an embodiment of the present disclosure, flow of
helium gas for time in between 85 seconds to 90 seconds is 0 standard litre per
minute. In an embodiment of the present disclosure, helium gas consumption in
non-continuous way reduces overall consumption of helium gas during
10 dehydration and sintering of the glass preform 102.
 The present disclosure provides numerous advantages over the prior art.
The present disclosure provides an improved method for sintering of the glass
preform with reduced helium gas consumption. In addition, the method used to
15 provide the glass preform with reduced cost. Further, the method reduces helium
gas consumption by 30 percent without affecting optical parameter of the glass
preform.
 The foregoing descriptions of pre-defined embodiments of the present
20 technology have been presented for purposes of illustration and description. They
are not intended to be exhaustive or to limit the present technology to the precise
forms disclosed, and obviously many modifications and variations are possible in
light of the above teaching. The embodiments were chosen and described in
order to best explain the principles of the present technology and its practical
25 application, to thereby enable others skilled in the art to best utilize the present
technology and various embodiments with various modifications as are suited to
the particular use contemplated. It is understood that various omissions and
substitutions of equivalents are contemplated as circumstance may suggest or
render expedient, but such are intended to cover the application or
30 implementation without departing from the spirit or scope of the claims of the
present technology.

We claim:

1. A method of dehydrating a cylindrical body (102) in a furnace (106), the
10 furnace (106) is defined by a first end and a second end, the method comprising:
injecting a heat transfer media in the furnace (106) from the first end of the
furnace (106), wherein the heat transfer media is injected discontinuously in the
furnace (106); and
15
enabling the heat transfer media to dispense from the second end of the
furnace (106).
2. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
20 wherein the heat transfer media is an inert gas.
3. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
wherein the cylindrical body (102) is a porous preform for use in manufacturing of an
optical fibre.
25
4. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
wherein the injecting comprising:
inserting the heat transfer media from the first end of the furnace (106) for
30 a first pre-defined time period, wherein the heat transfer media is inserted at one
of a pre-defined flow rate and a dynamic flow rate; and
21 / 23
5 halting or reducing flow of the heat transfer media for a second pre-defined
time period, wherein the second pre-defined time period is less than the first
pre-defined time period.
5. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
10 wherein the injecting comprising:
inserting the heat transfer media from the first end of the furnace (106) for
a first pre-defined time period, wherein the heat transfer media is inserted at one
of a pre-defined flow rate and a dynamic flow rate; and
15
halting or reducing flow of the heat transfer media for a second pre-defined
time period, wherein a ratio of the first pre-defined time period and the second
pre-defined time period is between 8 to 12.
20 6. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
wherein the injecting comprising:
inserting the heat transfer media from the first end of the furnace (106) for
a first pre-defined time period, wherein the heat transfer media is inserted at one
25 of a pre-defined flow rate and a dynamic flow rate; and
halting or reducing flow of the heat transfer media for a second pre-defined
time period, wherein a ratio of the first pre-defined time period is in a range of
25 - 60 seconds and the second predefined time period is between 1 to 10.
30
7. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
wherein the furnace (106) is a sintering furnace (106).
22 / 23
5 8. The method of dehydrating the cylindrical body (102) as claimed in claim 1,
wherein the method enables reduction in heat transfer media consumption of more
than 10%.