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    Product Data: Refratherm - Ace

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    Muntandwe george
    This document discusses Refratherm-ACC bricks, which are high strength insulating bricks manufactured through a collaboration between ACC and Refratechnik GmbH. [1] These chemically bonded bricks have high abrasion resistance, are lighter in weight to reduce load on kiln drives, form a protective glassy surface, and have lower thermal conductivity than traditional fireclay bricks to reduce heat loss. [2] The bricks are well-suited for use in preheaters, firing hoods, coolers, and preheating zones in cement plants, as well as other applications where energy conservation can significantly reduce costs.

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    © All Rights Reserved
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    Product Data: Refratherm - Ace

    Uploaded by

    Muntandwe george
    273 views7 pages
    This document discusses Refratherm-ACC bricks, which are high strength insulating bricks manufactured through a collaboration between ACC and Refratechnik GmbH. [1] These chemically bonded bricks have high abrasion resistance, are lighter in weight to reduce load on kiln drives, form a protective glassy surface, and have lower thermal conductivity than traditional fireclay bricks to reduce heat loss. [2] The bricks are well-suited for use in preheaters, firing hoods, coolers, and preheating zones in cement plants, as well as other applications where energy conservation can significantly reduce costs.

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    7818Refratherm_Bricks.pdf

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    This document discusses Refratherm-ACC bricks, which are high strength insulating bricks manufactured through a collaboration between ACC and Refratechnik GmbH. [1] These chemically bonded bricks have high abrasion resistance, are lighter in weight to reduce load on kiln drives, form a protective glassy surface, and have lower thermal conductivity than traditional fireclay bricks to reduce heat loss. [2] The bricks are well-suited for use in preheaters, firing hoods, coolers, and preheating zones in cement plants, as well as other applications where energy conservation can significantly reduce costs.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    273 views7 pages

    Product Data: Refratherm - Ace

    Uploaded by

    Muntandwe george
    This document discusses Refratherm-ACC bricks, which are high strength insulating bricks manufactured through a collaboration between ACC and Refratechnik GmbH. [1] These chemically bonded bricks have high abrasion resistance, are lighter in weight to reduce load on kiln drives, form a protective glassy surface, and have lower thermal conductivity than traditional fireclay bricks to reduce heat loss. [2] The bricks are well-suited for use in preheaters, firing hoods, coolers, and preheating zones in cement plants, as well as other applications where energy conservation can significantly reduce costs.

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    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 7

    PRODUCT DATA

    REFRACTORY BRICKS

    REFRATHERM - ACE
    The technological changes in cement production and the growing
    sizes of rotary kilns require much superior grade and quality
    of bricks to achieve uninterrupted kiln operation and low
    energy consumption. To satisfy this requirement, ACC
    collaborated with world’s largest and most well known refractory
    producer of cement industry - REFRATECHNIK, GmbH of
    Germany. By virtue of this alliance ACE is producing
    REFRATHERM-ACC, a high strength insulating brick for
    calcining zone of cement rotary kilns.

    These chemically bonded bricks are unique because of their


    following features:
    - High CCS ensures better abrasion resistance.
    - Substantial reduction of load on kiln drives due to their lighter
    weight.
    - Formation of glassy surface during application protects the body
    of refractory from destructive effect of alkali penetration.
    - Lower thermal conductivity, compared to high density
    fireclay bricks, ensures reduced heat loss through
    preheating and calcining zones of kiln.

    These bricks are ideally suited for use in the preheaters, firing
    hoods, coolers and preheating zones of cement plants. They are
    also proposed for use as back-up lining in steel plants, for lining
    the kilns in lime plants and other applications where energy
    conservation would lead to substantial reduction in direct
    costs.

    FILENAME Refratherm Bricks


    Page PAGE 1 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    COMMENTS ON REFRATHERM – ACC BRICK DATA

    REFRATHERM-ACC is a high strength insulating brick manufactured by dry pressing


    and subsequent pyroprocessing. Since the product is manufactured from a mixture of
    different raw materials, the properties are subject to variations as the raw material
    themselves may vary.
    The properties shown under typical value column are mean values from quality control
    figures and the properties under specification column are guaranteed values of the
    product.
    NATURE OF BOND : The bond may be ceramic, phosphate or chemical in nature.
    Where several bonds are used together, the bond is designated according to the nature of
    those bonds which play dominant role in the fired product.
    SHAPING : All the values mentioned in the data sheet relate to standard bricks only
    manufactured by dry pressing method.
    RAW MATERIAL BASE : This is the essential raw material conferring particular
    properties to the mixture.
    MAXIMUM SERVICE TEMPERATURE : The temperature is based on the product
    being heated on one face only in a clean atmosphere. Heating on more than one face,
    mechanical load, or the presence of corrosive dust, certain gases or slags will cause the
    maximum service temperature to alter.
    REVERSIBLE THERMAL EXPANSION : This test is done as per IS 1528 (PART
    19) : 1991.
    CHEMICAL ANALYSIS : Carried out according to IS 1527 - 1972.
    BULK DENSITY : Determined according to IS 1528 (PART 12) 1974.
    APPARENT POROSITY : Carried out according to IS 1528 (PART 8) 1974.
    COLD CRUSHING STRENGTH : Carried out according to IS 1528 (PART 4) 1974.
    PYROMETRIC CONE EQUIVALENT : The test is done as per IS 1528 (PART 1) -
    1980.
    REFRACTORINESS UNDER LOAD : Determined according to IS 1528 (PART 2)
    1974.
    THERMAL SHOCK RESISTANCE : Determined as per IS 1528 (PART 3) 1983.
    THERMAL CONDUCTIVITY : Determined as per water calorimetric method.
    SPECIFICATION FOR SHAPED BRICKS
    (1) The data relate to machine moulded standard bricks only.
    (2) For shaped items, specification will be same as standard bricks except
    the following variations :
    BD will be lower by 0.10 gm/cc, AP higher by 2 %, CCS lower by 100 kg/cm2 and RUL
    lower by 20 ºC from the specification values of standard bricks mentioned in data sheet.

    FILENAME Refratherm Bricks


    Page PAGE 2 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    PRODUCT: REFRATHERM-ACC
    TYPE: HIGH STRENGTH INSULATING BRICK
    NATURE OF BOND: CHEMICAL
    SHAPING: DRY PRESSED

    GENERAL PROPERTIES
    RAW MATERIAL BASE: SPECIAL INSULATING GROG
    MAX. SERVICE TEMPERATURE: 1300ºC
    REVERSIBLE THERMAL EXPANSION: 0.50 % at 1000 ºC

    CHEMICAL ANALYSIS, %
    TYPICAL VALUE SPECIFICATION
    SiO2 65.90 65 - 70
    Fe2 O3 2.20 2.50 max.
    TiO2 2.30 -
    CaO 0.75 -
    Al2 O3 23.60 20 - 24
    P2 O5 1.70 -
    MgO 0.68 -
    Na2 O 0.38 -
    K2 O 0.09 -
    LOI 2.00 2.00
    PHYSICAL PROPERTIES
    TYPICAL VALUE SPECIFICATION
    Bulk density, g/cc 1.64 1.55- 1.65
    Apparent porosity, % 34.0 33 - 35
    Cold crushing strength, kg/cm2 230 200 min.

    THERMAL PROPERTIES
    TYPICAL VALUE SPECIFICATION
    Refractoriness, SK/ºc + 18 / +1485 18 / 1485 min.
    2
    Refractoriness under load, 2 kg/ cm load
    Ta ºC 1360 1350 min.
    Te ºC 1470 1450 min.
    Thermal shock resistance, 950 ºC / air + 70 50 cycles min.
    Thermal conductivity, w/mk
    at 300 ºC HF 0.47 0.50 max.
    at 700 ºC HF 0.55 0.60 max.
    at 1000 ºC HF 0.59 0.60 max.
    SIZE TOLERANCE: 1 % or  1.5 mm whichever greater

    FILENAME Refratherm Bricks


    Page PAGE 3 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    REFRATHERM – ACC
    INTRODUCTION

    For conservation of thermal energy in cement plant rotary kilns, Refratechnik


    developed high strength insulating bricks for lining the calcining cone of the rotary
    kiln. These insulating refractory bricks have been marketed for over 20 years under
    the brand names of Refratherm, and are used in more than 400 plants all over the
    world.

    The Associated Cement Companies Ltd., is one of the largest producers of cement in
    India with an annual capacity of over 14 million tonnes. It is also one of the leading
    producers of refractories with an annual capacity of over 120,000 tonnes for use in
    cement and other industries.

    Refratechnik and ACC have now joined together to manufacture energy-saving bricks
    in India. Marketed under the brand names of REFRATHERM, these bricks will help
    reduce thermal consumption in process industries including cement.

    APPLICATION AREAS:

    REFRATHERM bricks are ideally suited for use in the pre-heater, firing hoods,
    coolers, and the calcining (preheating) zones of the rotary kiln in cement plants (Fig.
    1). They are also ideally suited for use as backup lining in steel plants, for lining the
    kilns in lime plants and other applications where energy conservation would lead to
    substantial reduction in direct costs.

    DEVELOPMENT OF TECHNOLOGY:

    The first step towards a better insulation in cement plants began with the use of burnt
    fireclay / high alumina bricks with high porosities. These bricks had enough
    mechanical strength but poor resistance to alkali / sulphate attack resulting in cracking
    and spalling. As the technology developed, double layer linings came into use. The
    relative movements between the two layers resulted in gradual pulverization of the
    backup lining. This problem was eliminated by the development of a combination
    brick. However, these bricks tended to separate at the interface layer due to tensions
    from mechanical stress and different expansion coefficients of the materials.

    FILENAME Refratherm Bricks


    Page PAGE 4 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    A successful solution to this problem was developed and is now adapted by ACC.
    These are chemically bonded Refratherm bricks. They are unique when compared
    with other insulation liners because of their:

    a. Lighter weight.
    b. Lower thermal conductivity.
    c. Better alkali resistance.
    d. Higher thermal shock resistance.

    There have been many attempts to make similar bricks, during the last twenty years of
    their application, but none of these have been successful.

    PERFORMANCE FEATURES:

    The lower thermal conductivity provides lower shell temperatures in working units. A
    comparative study by the research institute of the cement industry in Germany found
    that the use of Orylacc / Refrathacc equivalent bricks reduced shell temperatures by
    as much as 50 degrees C to 70 degrees C (Fig 2). The heat saving therefore is
    enormous. Research studies in operating plants all over the world have shown that
    there is a saving of upto 8.5 K cal per kg of clinker produced in smaller kilns. This
    saving increases to 15 to 30 Kcal / kg of clinker burned for long dry process and wet
    process kilns.

    LOWER FUEL CONSUMPTION

    Table 1 gives comparative data for the above mentioned types of insulating lining as
    regards thermal conductivity, limit of utilization, contact with clinker, shell
    temperatures, heat loss for an internal temperature of 1100 C and weight of the lining
    in tonnes / linear meter. The comparison is based on an overall thickness of 200mm
    for various combinations of dense bricks and insulating bricks.

    LOWER LINING WEIGHT:

    Compared with conventional high alumina bricks, the REFRATHERM range shows
    significant weight savings (Table 1). This reduces the load on the kiln drive
    significantly.

    FILENAME Refratherm Bricks


    Page PAGE 5 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    SUPERIOR ALKALI RESISTANCE

    In this process the lining of the calcining zone, suspension pre-heater, cyclone and
    pre-calciner, are exposed to atmospheres of alkali oxides, sulphates, chlorides and
    fluorides. As a result fireclay bricks with a higher alumina content are affected by
    alkali spalling due to formation of feldspar and subsidence thereof. The
    REFRATHERM bricks on the other hand exhibit excellent alkali resistance in these
    zones.

    PROPERTIES

    The properties of REFRATHERM bricks are given in Table 2. REFRATHERM


    bricks are recommended for larger diameter kilns with suspension pre-heater and / or
    pre-calciners. REFRATHERM is also a recommended product where chloride and
    alkali contents are on the higher side, because of its better alkali resistance properties.

    TABLE - 1

    FILENAME Refratherm Bricks


    Page PAGE 6 of NUMPAGES 7
    PRODUCT DATA
    REFRACTORY BRICKS

    Type of Thermal Limit of Hot face temp. 1100 C Weight of


    lining conductivity application lining 200mm
    (700) at contact T/m Index
    with Heat
    clinker Shell
    Kcal/ loss
    W/Km Temp Wm2
    m2h Kcal/m
    C 2
    h
    High
    Alumina 1.0 – 1.16-
    1200 C 258 4210 4896 3.93 1.0
    /Fireclay 1.16 1.35
    200m
    Compound
    bricks
    0.92 1.07 1200 C 240 3622 4212 3.18 0.81
    200mm
    BD=1.68
    Fireclay
    150mm
    Molar 0.78 0.91 1200 C 184 2400 2791 3.50 0.88
    bricks
    40mm
    Insulating
    light
    1150 C
    weight 0.4 0.47 150 1760 2047 2.55 0.64
    1200 C
    brick
    200mm
    Semi insul.
    Brick 1150 C
    0.6 0.7 189 2500 2908 3.15 0.8
    200mm 1200 C
    BD=1.65

    FILENAME Refratherm Bricks


    Page PAGE 7 of NUMPAGES 7

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