Technical

                                                                                            Cordierite Properties                                                                                        

 

Cordierite Properties
Maximum Service Temperature ( oC ) 1300
Bulk Density (gms/cc) 1.8 – 2.4
Apparent Porosity (%) 14 – 28
Hot Modulus of Rupture at 1200 oC (kg/cm2) 100 min
Thermal Shock Resistance VERY GOOD
Chemical Components (%)
Al2O3 35 – 48
SiO2 45 – 58
MgO 4 – 7
Major Phases Present Cordierite
Mullite

 

                                                                                               Do’s and  Dont’s                                                                                             

• If any damage is noticed then arrange for open delivery of the individual tiles, so that the full extent of damage can be assessed. In such cases care has to be taken to examining visually o.k. Tiles as they might have suffered internal damage.
• This can be checked by tapping with a 10mm dia iron rod of 150mm length and listening to the sound. Ringing sound indicates good ones and dull sound indicate inherent cracks.
• Even Wet Tiles Indicate Dull Sound And Therefore This Test Should Be Done After Drying The Tile If It Is Received In Wet Condition Due To Rain. Damage certificate should be taken from the transporter immediately after receipt of material otherwise insurance claim is not possible.
• If damage noticed customer has to call the local insurance surveyor for assessment of damage – arrange to send the report along with photographs to the supplier within a week time.
• Do Not Store The Tile Flat Up On Each Other
• Tiles should be allowed to rest on the edge and made to lean over the kiln or building wall. Soft gunny like materialsat the base will prevent corner chipping etc…
• The storage area should be covered and protected from rain/water logging problem etc.,
• In Case Tiles Get Wet It Is Necessary To Dry Them By Stacking Vertically In The Drier At 100*C For Sufficient Time
• The Test for Cracks/Soundness To Be Repeated Before Taking The Tile For Placement In The Kiln Car
• Proper refractory materials should be used as supports/props etc., low quality support materials due sagging etc., will induce stresses in the car super structure and results in collapse. Sillimanite or cordierite supports are recommended based on the temperature.
• The car base should be absolutely leveled and lined with proper refractory materials for volume stability.
• It is essential that all support should be in the same vertical line, so that the entire load ils transmitted through them instead of the tiles. (the entire supporting column including the props/1-beams/caps/car base brick work etc., should be material of good cold crushing strength, otherwise collapse of super structure will occur.
The Choice Of Tiles Size Should Be Done Carefully Bearing In Mind The Following:-
• OPTIMUM NUMBER OF PILLARS IN THE CAR DECK
• OPTIMUM SPAN OF TILES TO PREVENT WARPAGE/BREAKAGE
• OPTIMUM THICKNESS TO WITHSTAND THE LOAD
• This Ensures Long Life Of The Tiles Than Choosing Large Sizes And Low Thickness Which Result In Frequent Failure.
• Whenever the tiles are found to bend beyond (0.5%) of the diagonal length it is advisable to turn the tiles to lengthen the useful life of the tile.
• If the process involves rapid heating or cooling the proper kiln furniture material should be chosen by experimentation. Proper geometry and configuration of the tile will proved advantageous for enhancing the performance.
• It May Be Sometimes Advisable To Have One Or Two Dummy Runs With The Tiles (Float Firing) To Get Improved Life.
• It Is Very Important That Recommended Maximum Service Temperature Of The Kiln Furniture Should Never Be Exceeded.
Not to reduce the thickness first for cost/energy saving without full scale trials as it will result in higher consumption. Using higher thickness tile than optimum size will result in poor thermal shock.

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