4. DESCRIPTION
FIELD OF THE INVENTION
The present invention relates to development of special packing bricks and interlocking checker work / structure for recovering heat in thermal regenerator which would have high mechanical stability and make the flow turbulent during alternating cycle of gas and cold air for better fuel efficiency. The packing checker brick and checkered work / structure obtained of such checker brick are specifically adapted to absorb heat from the flue and cold air blown through the regenerator so that it can absorb heat from the checkered work before entering the furnace. The checkered bricks are obtained of selective refractory material and are of selectively develop shape and configuration whereby it is possible to have bricks with more surface area and exposed brick surface to act as a thermal surface. The interlocking projection in the bricks impart better mechanical stability and favour more turbulent flow during alternating cycle of gas and cold air.
BACKGROUND ART
Continuous high capacity glass tank furnaces, which operate at high temperature between 1450°C to 1650°C demand efficient heat recovery from the waste gases in conjunction with good heat transfer to provide combustion at a high pre-heat temperature. This ensures that the process operates with good thermal efficiency. The regenerator system made available has played a valuable part for achieving such efficiency for tank furnaces. The continuously operating recuperator does not give such high are preheat temperature as can be obtained with regenerators.

Additional heat recovery method such as waste heat boiler have so far been used in exceptional cases but high energy cause are giving rise to an increase in the use of such equipments.
It would be apparent from the above that there is always the need for providing packing bricks with effective surface area and arrangements whereby the flow would be more turbulent making better contact of air gas with the exposed area and much better heat recovery. Moreover, with required turbulent flow through the check work the stability of the checkered structure is also important and required to be addressed. Moreover, provision is required wherein all the flues can be approached from outside for cleaning.
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide for checkered bricks, which would give rise to more effective surface area, the mass per unit volume can be decreased and thereby facilitate the regeneration process.
Another object of the present invention is to provide for checkered bricks with selective projections and slots, which would impart higher stability to checkered setting protection and make extra heating area.
Yet another object of the present invention is directed to a checker setting which would leave opening in every tire which would facilitate approach to the few passages and make better contact between the heating surface and the air gas resulting in better fuel efficiency.
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Another object of the present invention is to provide for a packing bricks and arrangement of checker works / structure which would enable provision of selective thickness which would favour effective heating to take place resulting in better heat capacity.
Yet further of the present invention is directed to the provision of interlocking checker bricks which would enable forming of checker works / structure to recover heat in regenerator of glass furnace obtain of selective refractory material and defining rectangular projection and slots adapted to make the checker work interlocking with better mechanical stability and make the flow more turbulent during alternative cycle of gas and cold air.
Further object of the present invention is directed to provide maximum exposed surface area increased in the effective mass and increased the turbulence of air gas flow inside the checker work for better contact between the refractory and air gas for better fuel economy.
Another object of the present invention is directed to provide interlocked arrangement in checker brick for a stable checker work, which would be resistant to displacement.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention there is provided a check brick comprising
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a substantially rectangular top surface ;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
said top and bottom surfaces having atleast one projection and two unbound slots at the end regions thereof.
The above check brick thus comprises: a substantially rectangular top surface;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
said top and bottom surfaces having four said spaced apart projections and two said unbound slots at the end regions thereof.
The check brick according to an embodiment can comprise said unbound slots at the end regions are of equal length. Alternatively according to another aspect the check
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brick can comprise of the length of one said unbound slot being higher as compared to the length of the other unbound slot.
Preferably, the dimensions of the projections and slots are selectively determined based on the end use /application. The said spaced apart projections in the brick of the invention can provide for three bounded slots and two said unbound slots on the top and bottom surfaces.
According to another aspect of the invention the cheker brick is obtained of magnesia, alumina, zircon or mixtures thereof which are fired at elevated temperatures. The thickness of the bricks can vary from 50mm to 70mm.
In accordance with another aspect of the present invention there is provided a checker work to recover heat in regenerator furnaces comprising:
tiers of interlocked bricks which are rectangular in transverse and longitudinal cross section each brick includes top and bottom surfaces, two side walls and two end walls, at least two interlocking slots in each brick adapted to receive the interlocking slots of at least two bricks in an adjacent tier, the bricks in each tier being orthogonal to atleast one adjacent brick in an adjacent tier and being arranged in pattern including a series of parallel rows in which the bricks are spaced end to end.
The above checker work according to an embodiment can comprise bricks in alternate rows are of different size and are staggered with respect to the bricks in adjacent rows.
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In the checker work to recover heat in regenerator furnaces as disclosed above the bricks of alternate tiers are interlocked at the slots. The said bricks being interlocked with tier atop and underlying tier.
In accordance with a preferred aspect the checker work to recover heat in regenerator furnaces includes the check bricks comprising:
a substantially rectangular top surface ;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
said top and bottom surfaces having atleast one projection and two unbound slots at the end regions thereof.
In the above checker work the check bricks comprise a selective arrangement of checker bricks having at the top and bottom faces (a) one" projection and two unbound slots at the end regions thereof (b) four said spaced apart projections and two unbound slots of equal length at the end regions thereof and (c) four said spaced apart projections and two said unbound slots wherein the length of one said unbound slot is higher as compared to the length of the other unbound slot.
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In accordance with another aspect of the present invention there is provided a checker work structure to recover heat in regenerator furnaces comprising:
a) a plurality of bricks arranged in layers interlocked one atop the other to form
regenerative surface defining a series of flues for vertical passage of gases
alternatively to heat and to cool the brick;
b) each of the bricks being six sided and including projections and slots both in
top and bottom surfaces co-operating with slots of bricks of contiguous
layers;
c) atleast a majority of the bricks in certain of the layers being spaced from
other brick with four of its six sides in upright orientation and in contact with
passing flue gases and air.
In the above checker work structure to recover heat in regenerator furnaces the majority of bricks each have two of its sides forming upper and lower surfaces and portions of said surfaces are in contact with passing flue gases.
The checker work structure as above comprise a highly stable checker work with all the bricks in the alternate tiers interlocked and with exposed projections adapted to work as active thermal faces. Importantly, in the above checker work structure the projections are adapted to come in direct contact with the flue making the flue turbulent. The said alternate tiers are adapted to form passages for cleaning from outside.
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Checker brick in accordance with the present invention as disclosed above thus comprise a stepped top, stepped base two side walls and two end walls which are rectangular in shape wherein the end walls are right angle to the base.
As further detailed about the checker brick another aspect of the invention can comprise one for multi stepped top or bottom to match the corresponding steps of like bricks. Importantly it is possible to provide three different versions of the bricks depending upon the number of steps slots and length. In two such versions there are provided four steps and five slots, which match with the steps and slots of other bricks when the bricks are stacked one after another in interlocking manner making stable checker work.
The thickness of the brick can be 50-60mm. Or even less still such as to be stacked in an interlocking fashion making a stable checker work. Moreover, thickness of the brick is dictated by the material used to make the brick.
The checker bricks of the invention as discussed about are thus selectively adapted to form checker works that comprise layers of bricks. The bricks are interlock with the bricks of adjacent tire by making the slot of bricks in one tire with slot in bricks of contiguous tire. The bricks of the checker work define uniform flues for passage of gas air. In accordance with embodiment of a checker work made with tire with bricks having one step and two slots, the bricks are positioned perpendicular to two adjacent bricks in the same tire. Additionally, each brick is transverse to bricks located directly above and directly below it in adjacent tiers. Atleast a majority of bricks are each spaced from all other bricks within their respective tier.
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In the tiers comprised of bricks having three projections and five slots, the bricks of each tire is aligned in spaced rows.
The advantages of the reduced thickness of these bricks with projections and checker works constructed with these bricks are many. The shape as well as the arrangements of the bricks in the checker works breaks the symmetry of laminar gas flow making it more turbulent. This makes better contact between the air and gas with the surface of the bricks.
Additionally, this arrangements of the bricks allow increase exposed area due to its shape and space between the bricks. The projection and slots of the bricks contribute extra amount of bricks surface area that acts as an active thermal surface in the checker works wherein the bricks are spaced from all other bricks within their respective tiers. The bricks end walls contribute to the amount of effective exposed brick surface that acts as a thermal surface.
In addition to this, the arrangement of checker work gives more stability to the checker work due to projection and slots against turbulent flow than pigeon hole are basket waved setting against tangential shifting and statistical load.
Assuming the dimension of each flue remain the same in the checker work utilizing the bricks of the invention compare to the dimension of flue of prior checker work made with prior checker bricks, the mass per unit volume decreases. The reduction of mass per unit volume results in decrease of refractory cost. As the exposed area per unit volume increase along with flow area, this includes the thermal efficiency of
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the generator. Because of this improved efficiency the fuel consumption is significantly reduced.
The details of the invention, its object and advantages are explained hereunder in greater details in relation to non-limiting exemplary illustrations as per the following accompanying figures.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1: is a perspective view of an embodiment of a checker brick in accordance
with the present invention;
Figure 2: is a perspective view of another embodiment of the packing brick (PB) in
accordance with the present invention;
Figure 3: is a perspective view of yet another embodiment of the packing brick (PB)
in accordance with present invention; and,
Figure 4: is a fragmentary perspective view of a checker work obtained using a
selective arrangement of the packing bricks as per embodiments according to figures
1 to 3 above.
Reference is first invited to Figure 1 which illustrates the packing brick (PB) in accordance with the present invention obtained of refractory material comprising particularly selected from magnesia, mag-chrome, magnesia zircon having zirconia content from 12-20%. As shown in said figure the brick comprises base and top parallel each other. The brick further includes side walls that are parallel to each other. The end walls (EW) of the bricks is a right angle to the base and that are parallel to each other. Overall the brick is having a rectangular shape.
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Also, as illustrated above embodiment of the packing brick of the invention the top and base portion has one mounting projection (MP). The mounting projection (MP) are also preferably in the shape of rectangle. The top and base include two slots (SL) which are unbounded at the end. The length of the unbounded slots is about 63mm.
Also, for illustrating purposes, the bricks as shown in Figure 1 can have an overall length of 260 mm. The thickness of the brick is 60mm. and the width of the brick is about 170mm. The length of the projection can be about 134mm. With a height of 10 mm.
Reference is now invited to accompanying figure 2 which illustrates a brick having similar shape as in the brick of figure 1 where the top and the base are parallel to each other. The sidewalls and end wall are also shown parallel to each other. However, according to this embodiment, these bricks have four projections (MP) three bounded (BMP) and two unbounded slots (UST).
For illustrating purposes, the overall length of such a brick can be 395mm. The length of projection is 37mm. With a height of 10mm. The length of bounded slot is about 60mm. And unbound slot is about 29mm. The projections and slots are similar in base as well as in the top, The thickness of the brick is 60mm. And the width of the brick is about 135mm.
Reference is now invited to accompanying figure 3 which illustrate a brick i.e. similar in construction to the brick as illustrated in figure 2 but having a different overall length. For illustration purposes, the length of the brick is 427.5mm. The other
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dimension of the brick are same as in figure 2 except the two unbound slots. The length of unbound slot in one side is 25mm. Whereas the length of unbound slot in the other side is 61.5mm.
Reference is now invited to accompanying figure 4 which illustrates a checker work obtained in accordance with the invention utilizing combination of various embodiments of the brick of the invention as shown in figures 1, 2, and 3 above.
As apparent from the said figure, the first tier of the checker work is made of bricks as per figure 1. The bricks embodiment of Figure 1 of the said first tier are spaced from each other such that no part of the brick is in contact with any other brick in this tier. Each brick is placed such that the brick is substantially in the same line in one direction and parallel to adjacent brick in other direction. Therefore, a series of row and column are formed where rows and column are perpendicular to each other. A second tier compression is obtained of brick work comprising of bricks as per the embodiment illustrated in figure 2 and figure 3 which is arranged over the first tier in such a way that each brick of the second tier interlocks with two bricks of the first tier that are located about a vertical plain. This interlocking is accompanied by matching the slots of the bricks in the second layer with the unbound slots of the bricks of the first tier. The bricks of the second tier are also atop and orthogonal to a first tier brick that extend between the two meted first tier bricks.
Subsequent tier are made by the repeatedly mounting the bricks (PB 4) and PB 2, PB - 3 in alternate tier in similar fashion. As shown in figure 4, in the third tier is located directly above its corresponding bricks in the first tier. The positioning of each brick (PB 4) creates a plurality of flues to which heated gas and air travel.
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The checker work is completed by repeatedly forming alternating tier in the described manner. The bricks of each row are aligned end-to-end with each row. Rows of each tier are transverse to rows of adjacent tiers.
The shape of the bricks and spacing between the bricks provide more exposed brick area than prior bricks and checker work and thereby provide a more efficient heat transfer. In the checker work illustrated in figure 4 all six surfaces of the bricks are exposed.
Additionally, each brick aligned and stacked in other bricks in contiguous tiers located below and above them has a projection. Projection exposed which leads to extra exposed the facility. This arrangement of the bricks provides for more turbulence and reduces the laminar flow of gas and air. These advantages are provided by the projection and slot arrangements of the bricks.
Comparative studies were carried out to ascertain the advantages in the packing bricks and the interlocking checker works obtained thereof for recovering heat in thermal regenerators vis-a-vis the conventional chimney block regenerators were carried out and the results noted are provided in following Table 1

TABLE 1
TABLE 1 Furnace no1 Furnace no2 Furnace no3
Furnace (Melter) Size: in M2, 110 105 110
Pulling Rate- T/M2, 2.65-3.3 2.65-3.0 2.9-3.1
Furnace Temp(Melter Tank):(OPT) in °C, 1565-1580 1515-1530 1540-1550
Type of Firing : End End Fired End Fired End fired
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Fired/ Cross Fired,
No of Port- , 2 2 2
Type of Fuel-Oil/natural Gas,3 Natural Gas Furnace Oil Furnace oil
Calorific value-,Net 8410 Kcal/NM3 10000 Kcal/Kg. 10200Kcal/kg
Regenerator:
Single pass/double pass/three pass Single pass Single pass Single pass
Dimension- HXLXB(mm) 15021x7010x 5575 15144x7873x 4136 16370x6050x480 0
transition height: in mm, 2753(1606 from checker top+1147 crown rise) 2993(1734 from checker top +859 crown rise) 2695
Checker bed height: in mm, 11100 10105 12000
Type of packing brick used like- Chimney block Brick Mertz type Chimney block
MAGZIR TY1- Height (mm) 600+2700 805 mm 4500
MAGZIRT TY II-Height, (mm) 4045 9300 mm 7500
Any other - Height, (mm)MGT-98 TYPE-I 3750 Nil Nil
Temp at the top course of regenerator- , 1395 1340 1360
Air quantity blown/hr - ,NM3 140000-16000 11000-13000 14000-16000
Fuel quantity/hr- , 1400-1700 NM3/ hr 1100-1300 Lt./hr 1300-1400 Lt/hr
In-let temp of combustion air entering tank Never measured. It may be around 1200 degC Never measured. It may be around 1200 degC May be around 1200 degC
outlet temp to chimney- °C, 400-435 415-435 400-425
Cycle time- , 20 20 20
% of cullet used- , 30-50 40-60 30-40
Regenerator crown 1317-1390 1325 1320-1350
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temp- °C
Flame temp- °C 1675+-25 1750+/-25 1800+/-25
Mass per unit volume Kg/m3 1127.64 1154.665 965
Effective surface area in m2 6833.16 3962.69 5107.87
Exposed area/m3 in M2 15.75 12.04 14.65
As per the results obtained as above, Furnace no 1 & Furnace no 3 are using chimney blocks in their regenerator where as in Furnace no 2 in accordance with the present invention the packing bricks were used. Although mass/unit volume in furnace no 2 is more compare to other two furnaces but the effective surface area of the furnace no 2 is more than other two furnaces even the dimension of the furnace is smaller compare to furnace no 1 and furnace no 2 where chimney blocks are used. This results in lower fuel consumption in Furnace no 2.
The above thus goes to demonstrate the desired increase in surface area achieved by the system of the invention and also how the present system vis-a-vis the conventional art is also fuel efficient.
It is further possible by way of the above checker work using the combination of bricks of the invention to have a hose and overhanging projection adapted to increase the turbulence within the flues. Air and gas flowing along a brick in one tier is adapted to encounter the base of a brick in the same vertical plain but different tier.
Additionally this checker setting is more stable compare to prior checker work as all the bricks are interlocked in slots and chances of displacement is removed. Also this
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checker work provides facility to clean the flues from outside without disturbing the checker setting or offset firings.
Although the preferred embodiment of this invention have been shown and described it should be noted that various modification and re-arrangement of the bricks and checker works may be made without departing from the scope of the invention as disclosed and claimed herein.
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5. CLAIMS WE CLAIM:
1. A check brick comprising
a substantially rectangular top surface ;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
said top and bottom surfaces having atleast one projection and two unbound slots at the end regions thereof.
2. A check brick as claimed in claim 1comprising
a substantially rectangular top surface;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
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said top and bottom surfaces having four said spaced apart projections and two said unbound slots at the end regions thereof.
3. A check brick as claimed in claim 2 wherein said unbound slots at the end regions
are of equal length.
4. A check brick as claimed in claim 2 wherein the length of one said unbound slot is
higher as compared to the length of the other unbound slot.
5. A check brick as claimed in anyone of claims 1 to 4 wherein the dimensions of the
projections and slots are selectively determined based on the end use /application.
6. A check brick as claimed in anyone of claims 2 to 5 wherein said spaced apart
projections provide for three bounded slots and two said unblound slots on the top
and bottom surfaces.
7. A check brick as claimed in anyone of claims 2 to 6 obtained of magnesia,
alumina, zircon or mixtures thereof which are fired at elevated temperatures.
8. A check brick as claimed in anyone of claims 2 to 7 wherein the thickness of the
bricks vary from 50mm to 70mm.
9. A checker work to recover heat in regenerator furnaces comprising:
tiers of interlocked bricks which are rectangular in transverse and longitudinal cross section each brick includes top and bottom surfaces, two side walls and two end
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walls, at least two interlocking slots in each brick adapted to receive the interlocking slots of at least two bricks in an adjacent tier , the bricks in each tier being orthogonal to atleast one adjacent brick in an adjacent tier and being arranged in pattern including a series of parallel rows in which the bricks are spaced end to end.
10. A checker work to recover heat in regenerator furnaces as claimed in claim 9
wherein the bricks in alternate rows are of different size and are staggered with
respect to the bricks in adjacent rows.
11. A checker work to recover heat in regenerator furnaces as claimed in anyone of
claims 9 or 10 wherein the bricks of alternate tiers are interlocked at the slots.
12. A checker work to recover heat in regenerator furnaces as claimed in claim 10
wherein the bricks are interlocked with tier atop and underlying tier.
13. A checker work to recover heat in regenerator furnaces as claimed in anyone of
claims 9 to 12 wherein the check bricks comprise
a substantially rectangular top surface ;
a substantially rectangular bottom surface, wherein the top and bottom surfaces are parallel to each other;
two rectangular side walls wherein the side walls are parallel to each other and at right angle to top and bottom walls;
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said top and bottom surfaces having atleast one projection and two unbound slots at the end regions thereof.
14. A checker work to recover heat in regenerator furnaces as claimed in
anyone of claims 9 to 13 wherein the check bricks comprise a selective arrangement
of checker bricks having at the top and bottom faces (a) one projection and two
unbound slots at the end regions thereof (b) four said spaced apart projections and
two unbound slots of equal length at the end regions thereof and (c) four said
spaced apart projections and two said unbound slots wherein the length of one said
unbound slot is higher as compared to the length of the other unbound slot.
15. A checker work structure to recover heat in regenerator furnaces comprising:
d) a plurality of bricks arranged in layers interlocked one atop the other to form
regenerative surface defining a series of flues for vertical passage of gases
alternatively to heat and to cool the brick;
e) each of the bricks being six sided and including projections and slots both in
top and bottom surfaces co-operating with slots of bricks of contiguous
layers;
f) atleast a majority of the bricks in certain of the layers being spaced from
other brick with four of its six sides in upright orientation and in contact with
passing flue gases and air.
16. A checker work structure to recover heat in regenerator furnaces as claimed
in claim 15 wherein majority of bricks each having two of its sides forming upper
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and lower surfaces and portions of said surfaces are in contact with passing flue gases,
17. A checker work structure to recover heat in regenerator furnaces as claimed in
anyone of claims 15 or 16 comprising a highly stable checker work with all the bricks
in the alternate tiers interlocked and with exposed projections adapted to work as
active thermal faces.
18. A checker work structure to recover heat in regenerator furnaces as claimed in
anyone of claims 15 to 17 wherein the projections are adapted to come in direct
contact with the flue making the flue turbulent.
19. A checker work structure to recover heat in regenerator furnaces as claimed
in anyone of claims 15 to 18 wherein the said alternate tiers are adapted to form
passages for cleaning from outside.
20. A check brick and a checker work/structure to recover heat in regenerator
furnaces using said checker bricks substantially as herein described and illustrated
with reference to the accompanying figures.
6. DATE & SIGNATURE


Dated this 26th day of April, 2006
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…………………………
GAUTAM BANERJEE Of KHAITAN & CO. (Applicants Agent)