The present invention relates to cement kiln burner tip with modular, segmented
refractory block and mode of fixation thereof.
More particularly this invention pertains to modular, segmented refractory blocks for
clamping onto cement kiln burner tip for prolonging the life of burner tubes and also
has a provision for mechanical device to affix the segmented refractory blocks onto
the burner tubes to ensure easy fixation and removal thereof for replacing, as and
when needed.
Life of the burner tip plays a vital role on down time of cement rotary kiln which is
exposed to a number of destructive forces which tend to reduce the life of the burner
tip. Some of these destructive forces, inter alia, are—(1) corrosion from clinker dust,
(2) abrasion on account of high turbulence of clinker dust with high velocity rising up
from the cooler which impinge on the burner tip resulting in erosion of the protective
refractory cover, (3) thermal spalling and falling off of chunks of refractory materials
or appearance of cracks as observed during heating up and also in the course of 'down
time', (4) the burner tip is exposed to high temperature resulting from direct radiation
of flame inside the cement kiln which often proves to be deleterious on continuous
exposure in the course of working of the cement kiln.
Conventionally high alumina castables are normally used for protecting the burner tip.
Casting is done on the burner shell pre-welded with steel anchors by employing
conventional procedures. The standard castables used in cement industries have 'cold
crushing strength (CCS) of around 500 kg./cm.2 after drying at 110°C and around 800
kg./cm.2 after firing at 1500°C.
Generally the life of castable applied in burner tip in a cement kiln varies between 1
and 12 months, depending on the raw mix design, kiln operating condition, burner
placement, type of fuel, degree of turbulence, abrasion with clinker dust, chemical
corrosion, maintenance practice, and the like factors. These factors often vary within
considerable limits depending on the nature of raw materials, size of the kiln and
operating conditions.
The conventional procedures referred to above have been found to suffer from a
number of drawbacks e.g. (i) high installation time, (ii) improper installation—on
account of non-uniformity of castable thickness, (iii) high heat of time and (iv) high
dismantle time, to name a few important factors among others. The foregoing factors
lead to enhancement on down time of cement kiln resulting in production loss.
However, it may be noted that castable can be installed in a deformed shell by
adopting standard means, which may be regarded as an advantage of the prior art.

The most serious drawback of the conventional mode of applying refractory cladding
on cement kiln burner tip is the entire castable structure will have to be brought down
or dismantled in the event of spalling and development of cracks or fissures. A new
casting with castable to be made with anchor welding.
The present invention attempts to overcome the drawbacks pointed out hereinabove
and provide modular, segmented refractory blocks which can be replaced separately in
isolation, leaving the remaining parts or segments intact, in other words, the affected
parts of the burner tip cladding can be replaced by fresh refractory blocks, thereby
reducing down time and also saving considerably in the cost of materials. Apart from
the unique provision of segmented refractory blocks, this invention also provides a
novel way for affixing the segmented refractory blocks on to the burner tip by means
of screws, nuts and bolts, which ensures speedy removal and replacement of the
affected or damaged parts by new bodies provided with adequate housings or recesses
in the segmented block members. Provision for such mechanical means to affix the
fresh block(s) after removal of the affected/damaged block(s) is a totally novel
concept developed by the Applicants which has not been tried in industry or published
anywhere heretofore.
The principal object of this invention is to provide an improved cement kiln burner tip
refractory block which is modular in nature and segmented in structure.
A further object of this invention is to provide an improved refractory bodies which
are endowed with high strength, and offering greater resistance to thermal shock,
abrasion and corrosion.
A still further object of this invention is to provide alumino silicate or aluminous
materials, optionally with cement, and with silicon carbide, with or without inclusion
of zircon sand or flour.
A still further object of this invention is to provide shaped refractories of modular
nature in segmented form using reinforcement such as steel fibre or ceramic fibre.
Another object of this invention is to provide fixing arrangement of steel components
to burner pipe to facilitate affixing of refractory blocks in segmented form with the
help of ceramic or stainless steel fixing means selected from, inter alia, blocks,
anchors, hooks, slots, bolts, clamps with bolts and/or welding, depending on specific
requirements and end usage.
A still another object of this invention is to provide a convenient fixing arrangement
of refractory components to burner pipe.

The foregoing objects are fulfilled by the present invention which provides cement
kiln burner tip refractory block, characterized in that shaped refractories of higher
strength, enhanced thermal shock resistance and resistance against abrasion and
corrosion made from alumino silicate materials selected from the group of bauxite,
fused alumina (white or brown), tubular alumina and/or sintered alumina in amounts
ranging from 5 to 95% by weight, optionally in the presence of cement and silicon
carbide in the range of 1 to 50% by weight, and, if desired, employing steel or ceramic
fibres for reinforcing the cast refractory bodies in modular, segmented form for
cladding round the burner pipe to prevent it from wear and tear and enhance its life by
at least 1.5 times.
The refractory protective cover applied on the burner tube is optimally alumino
silicate material employed in an amount of 30% by weight and silicon carbide is
selected with a size fraction of 1 mm. to 400 mesh, wherein the refractory components
are added to a suitable solvent like water and mixed in a mechanical mixer of inclined
or counter current type having a control shaft, equipped with scraper arrangement
and/or pan rotating arrangements, followed by casting in a mould made of steel, wood
or polymeric materials, optionally with vibration and, if desired, pre-firing the
modular, segmented bodies, cooled them to ambient and then fitting them on burner
tip.
Only high grade alumina with an alumina content of 40% to 95% is employed for
making fire shapes or low impurity alumino silicate materials are used for making
modular segmented refractory bodies with optional inclusion of zircon sand or flour,
and the refractory components may be cast or pressed.
There is included as reinforcements steel fibres of SS200, SS300 series, preferably
SS304, 310 and 316, in an amount of 1 to 10% by weight of the refractory component,
or ceramic fibres like alumino silicates in the same amount, having dia of 0.1 to 1 mm.
and length of 5 to 15 mm., preferably 10 mm.
The subject invention also pertains to a novel mode of fixation of modular, segmented
refractory blocks onto cement kiln burner pipe, which resides in following the under
noted sequence of steps:
(a) cleaning the burner pipe from adhering foreign bodies;
(b) carrying out welding as and when necessary or intended for the purpose of
restoration;
(c) smoothening the surface of the burner pipe by application of refractory mortar,
castables or any other priming means;

(d) fixing to burner pipe steel or ceramic bodies selected from the group of, inter alia,
blocks, anchors, hooks, slots, clamps with bolts and the like, either by welding or
by providing suitable anchoring means for affixing such steel or ceramic bodies to
the said burner pipe;
(e) wrapping the burner pipe with ceramic insulation paper made of alumina or
alumino silicate fibre of thickness varying between 1 and 5 mm., preferably 3 to 5
mm., prior to fixation of the segmented refractory blocks onto designated
locations; and
(f) assembling a plurality of refractory components with thickness variation from 50
to 350 mm., preferably from 50 to 200 mm., for the said components on the upper
part and from 50 to 450 mm., preferably 50 to 300 mm., in the lower part of the
burner pipe.
In fixing the cladding refractory bodies onto burner pipe, clamping arrangements by
way of steel or ceramic blocks are provided with matching bolts for holding the
refractory segments in position, with a minimum of 2 such blocks per refractory
segment, preferably 2 to 6 in number, carrying bolts with spring/split washers, for
cladding the burner pipe.
Separate counter bores are provided in the refractory blocks for socket held bolts,
usually Allen bolts.
An alternative mode of fixation of refractory component may be carried out with the
help of tie rods, numbers of which may vary from 1 to 5 per component, a longer
member of which is used with guide tube filled in block and guide flange welded on
burner tube, at the end of the block towards the burner tube, and the tie rod is
tightened with nut and bolt with spring/split washer in adequate numbers to
compensate for thermal expansion with dynamic tensile and compressive load,
followed by lock nut to prevent any possibility of slippage, wherein all the constituent
components are made either of stainless steel (SS300) or ceramic material.
The present invention will now be further amplified by the illustrative drawings
accompanying this specification, wherein:
Fig. 1 shows an installation with castable single component monolithic
structure of burner tip, which is made in one piece cladding the
burner tube.
Fig. 1(a) gives a perspective view of burner pipe monolithic installation.

Fig. 1(b) depicts a front view of monolithic refractory cover on burner
pipe.
Figs. 2(a) and 2(b) show fixing arrangement of steel components to burner pipe.
Figs. 2(c) and 2(d) show fixing arrangement of refractory segment to burner tip.
Fig. 2(e) gives a cross-sectional view of the segmented refractory bodies
round the burner pipe including the clamping arrangement.
Fig. 3 illustrates a refractory segment assembly with burner pipe by
deploying tie rod arrangement.
Turning next to the individual figure of the drawings, the following numerals
designate specific components of the burner tip assembly.
In Fig. 1(a), '1a1' stands for a perspective view of the burner pipe with monolithic
castable lining. In Fig. 1(b), '1b1' gives a front view of monolithic refractory
installation around a burner pipe.
In Fig. 2(a), numerals '2a' and '2a2' show refractory segments for upper and lower
parts of burner tip, respectively. In Fig. 2(b), numerals '2b|' shows a clamping block,
'2b2' stands for a bolt with spring washer and '2b3' indicates the burner pipe, whereas
in Fig. 2(c), '2c1' indicates the location of a counter bore for socket head bolt, with the
help of which the refractory segments are firmly anchored to the burner tube. With
regard to Fig. 2(d), reference numeral '2d1' indicates the refractory segment covering
the upper part of the burner tip, '2d2' is the nozzle of the burner, '2d3' shows air nozzle
of the burner and '2d4' stands for refractory segment covering the bottom part of
burner tip.
Referring next to Fig. 2(e) showing a cross-section of the segmented refractory
cladding of the burner pipe as well as their mode of fixing, numeral '2e1' illustrates
the clamping arrangement for refractory segment(s) at the upper region of the burner
pipe and '2e2' stands for clamping arrangement of refractory segment at the bottom of
the said pipe.
Fig. 3 represents an alternative feature in regard to the mode of fixing the refractory
segments by deploying tie rod arrangement, wherein '3e1' is the guide flange, '3e2' is
the clamping flange, '3e3' shows tie rod with guide pipe and '3e4' stands for bolt with
spring washer,—the entire arrangement assuming the shape of a space-shuttle module.
As pointed out earlier, the anchoring or clamping arrangements may be made of
stainless steel or ceramic. Usually bolts, clamps, blocks, etc. are made of stainless

steel of SS300 series, preferably selected from SS304, 310 and 316. For higher
diameter burners, refractory components of larger dimensions are fixed and held in
place by tie rods.
Advantages:
The subject invention offers a number of advantages, some of which, inter alia, are
outlined below:
1. For fixing the modular, segmented refractory components time consuming
procedures like air drying, heat treatment and/or curing are not required.
2. Segmented refractory components require substantially less installation time.
3. Mode of installation is user-friendly, as it is capable of achieving rapid heat-up
cycle without formation of cracks/fissures, or any possibility of spalling.
4. Easy repairs, since the invention offers attachment of different refractory
segments to the burner pipe, any damage occurring during operation
necessitates changing only the affected/damaged segment, leaving other
segments intact and undisturbed.
5. Life of the burner pipe has been found to be at least 1.5 times more than prior
art, using monolithic castables.
6. The evolved procedure results in considerable cost saving, reduction in
downtime and enhancement of operational time—all of which render the
invention highly cost-effective.
As the present invention may be embodied in several forms without deviating or
departing from the spirit or essential characteristics thereof, it should be understood
that the above-described features/examples are not limited by any of the details of the
foregoing description, unless otherwise specified, but rather should be construed
broadly within its spirit and scope as defined in the appended claims and, therefore, all
changes and modifications that fall within the meets and bounds of the claims, or
equivalences of such meets and bounds are therefore intended to be embraced by the
claims appended hereafter.

We claim:
1. Cement kiln burner tip refractory block, characterized in that shaped refractories of
high strength, enhanced thermal shock resistance and resistance against abrasion
and corrosion made from alumino silicate materials selected from the group of
bauxite, fused alumina (white or brown), tabular alumina and/or sintered alumina
in amounts ranging from 5 to 95% by weight, optionally in the presence of cement,
and silicon carbide in the range of 1 to 50% by weight and, if desired, employing
steel or ceramic fibres for reinforcing the cast refractory bodies in modular,
segmented form for cladding round the burner pipe to prevent it from wear and
tear and enhance its life by at least 1.5 times.
2. Cement kiln burner tip as claimed in Claim 1, characterized in that optimally
alumino silicate material is employed in an amount of 30% by weight and silicon
carbide is selected with a size fraction of 1 mm. to 400 mesh, wherein the
refractory components are added to a suitable solvent like water and mixed in a
mechanical mixer of inclined or counter current type having a control shaft,
equipped with scraper arrangement and/or pan rotating arrangements, followed by
casting in a mould made of steel, wood or polymeric materials, optionally with
vibration and, if desired, pre-firing the modular, segmented bodies, cooled them to
ambient and then fitting them on burner tip.
3. Cement kiln burner tip as claimed in Claims 1 and 2, characterized in that only
high grade alumina with an alumina content of 40 to 95% is employed for making
fire shapes or low impurity alumino silicate materials are used for making modular
segmented refractory bodies with optional inclusion of zircon sand or flour, and
the refractory components may be cast or pressed.
4. Cement kiln burner tip as claimed in Claims 1 to 3, characterized in that there is
included as reinforcements steel fibres of SS200, SS300 series, preferably SS304,
310 and 316, in an amount of 1 to 10% by weight of the refractory component, or

ceramic fibres like alumino silicates in the same amount, having dia of 0.1 to 1
mm. and length of 5 to 15 mm., preferably 10 mm.
5. Cement kiln burner tip refractory block, substantially as hereinbefore described
with particular reference to the accompanying drawings.
6. Mode of fixation of modular, segmented refractory blocks onto cement kiln burner
pipe, wherein the said refractory blocks are fixed to the exterior of the burner pipe
by following the undernoted sequence of steps:

(a) cleaning the burner pipe from adhering foreign bodies;
(b) carrying out welding as and when necessary or intended for the purpose of
restoration;
(c) smoothening the surface of the burner pipe by application of refractory
mortar, castables or any other priming means;
(d) fixing to burner pipe steel or ceramic bodies selected from the group of,
inter alia, blocks, anchors, hooks, slots, clamps with bolts and the like,
either by welding or by providing suitable anchoring means for affixing
such steel or ceramic bodies to the said burner pipe (2b1, 2b2 and 2b3);
(e) wrapping the burner pipe with ceramic insulation paper made of alumina or
alumino silicate fibre of thickness varying between 1 and 5 mm., preferably
3 to 5 mm., prior to fixation of the segmented refractory blocks onto
designated locations; and
(f) assembling a plurality of refractory components (2a1 and 2a2) with
thickness variation from 50 to 350 mm., preferably from 50 to 200 mm., for
the said components on the upper part (2d1) and from 50 to 450 mm.,
preferably 50 to 300 mm., in the lower part of the burner pipe (2d2).
7. Mode of fixation as claimed in Claim 6, wherein clamping arrangements by way of
steel or ceramic blocks (2b1) are provided with matching bolts for holding the

refractory segments in position, having a minimum of 2 such blocks per refractory
segment, preferably from 2 to 6 in number, carrying bolts with spring/split washers
(2b2), for cladding the burner pipe (2b3).
8. Mode of fixation as claimed in Claims 6 and 7, wherein separate counter bores are
provided in the refractory blocks for socket head bolts, preferably Allen bolts (2c).
9. Mode of fixation as claimed in Claim 6 to 8, wherein an alternative fixation of
refractory component is carried out with the help of tie rods, numbers whereof
vary from 1 to 5 per component, a longer member of which is used with guide tube
(3e2) welded on burner tube, at the end of the block towards the burner tube, and
the tie rod is tightened with nut and bolt with spring/split washer (3e4) in adequate
numbers to compensate for thermal expansion with dynamic tensile slippage, and
wherein all the constituent components are made either of stainless steel (SS300)
or ceramics.
10. Mode of fixation of modular, segmented refractory blocks onto cement kiln burner
pipe, substantially as hereinbefore described with particular reference to the
accompanying drawings.

ABSTRACT

In conventional procedure the cement kiln burner pipe normally used to be
cladded all around by castables provided monolithically which needed plant shut
down for repair work and/or replacement adding to the down-time, loss of production
and escalation of cost for replacement of the entire refractory cover, even if there was
a small crack development and/or spalling.
The present invention attempts to provide an effective answer to the aforesaid
problems associated with the prior art and relates to cement kiln burner tip refractory
block, characterized in that shaped refractories of high strength, enhanced thermal
shock resistance and resistance against abrasion and corrosion made from alumino
silicate materials selected from the group of bauxite, fused alumina (white or brown),
tabular alumina and/or sintered alumina in amounts ranging from 5 to 95% by weight,
optionally in the presence of cement, and silicon carbide in the range of 1 to 50% by
weight and, if desired, employing steel or ceramic fibres for reinforcing the cast
refractory bodies in modular, segmented form for cladding round the burner pipe to
prevent it from wear and tear and enhance its life by at least 1.5 times.
This invention also discloses a mode of fixation of segmented refractory
components to burner pipe.