IMPERVIOUS CARBON AND GRAPHITE BRICKS & TILES
It is made from low ash,hard calcined grade carbon/electro-graphite powder which are selected carefully and mixed with bituminous binders in varying proportions. The mix is then extruded or moulded as per requirement and heated to high temperatures in a furnance. The stock material formed has high porosity around 25%. since its mechanical strength and abrasion resistance is not adequate, the product is impregnated with resins of unmatched chemical resistance, in vacuum autoclaves depending on duty service. The final material is thus made impervious to liquids and gases.
This process greatly improves all physical properties such as compressive and impact strength, abrasive resistance, bringing down porosity of the brick to minimum. The process though cumbersome has found to be unique in combating any chemical attack of corrosion and abrasion at elevated temperatures.
It has been established that impervious carbon is an excellent material of construction especially in areas where process conditions are highly corrosive and abrasive above 700C
range, where most of the rubber linings and plastics start attaining their distortion temperature and tend to harden and crack gradually. Impervious carbon and graphite materials withstand continously temperatures up to 1900
C and such linings have been known to be working for years, trouble free.
PROPERTIES OF IMPERVIOUS CARBON AND GRAPHITE :
|1. Crushing strength kg/cm. sq
|2. Transverse strength kg/cm.sq.
|3. Bulk density
||1.6 - 1.7
|4. Ash content
|5. Abrasion resistance
|6. Resistance to thermal shock
|7. Thermal conductivity
|8. Mechanical strength
THESE PROPERTIES ARE AVERAGE OF TESTS CONDUCTED BY US.
WHEN TO PREFER CARBON LINING OVER OTHER MATERIALS
1. When there are frequent, temperature fluctuations and reactions in a reactor, acid proof bricks cannot take fluctuations and they crack fast.Over rubber lining of 6 mm thk carbon brick or tile lining gives trouble free service without plant down - time.
2. In hot caustic soda or flourine, chlorine and varying sulphuric acid concentrations , water dilutions, rubber - lining or - proof brick lining is for best performance.
3. Acid - proof brick has a minimum thickness of 40 MM , where as a 12 MM thk. Carbon tile lining is equally strong and anti-corrosive , and does not bring down volume of holding or restrict inner diameters while lining in a M.S.R.L. pipe or ducting.
4. Carbon linings are less than half the weight of acid - proof bricks and can be lined on tank tops covers where acidic vapoures damage rubber - lining.
5. Where S.S.and Hastalloy materials fail due to galvanic attack of Sulphuric acid and halogens.
IMPERVIOUS CARBON & GRAPHITE --- OUTSTANDING PROPERTIES.
1. High crushing strength and impact resistance.
2. Withstands severe corrosion and abrasion upto 190'C.
3. High thermal conductivity --- next to Copper and Aluminium.
4. Excellent resistance to thermal shocks.
5. Not wetted by liquids.
6. Impervious to liquids and gases.
7. One-third the weight of steel.
8. Excellent lubricating properties, and good machinability on lather for any shapes etc'
9. Half the cost of teflon S.S. glass.
USES OF IMPERVIOUS CARBON AND GRAPHITE MATERIALS
1. PHOSPHATIC INDUSTRY.
Carbon bricks and tiles with carbon cements are used for lining of reactors, seal Tanks, flash chambers, flash coolers and ducting, evaporation section spools, Gypsum launders, chutes – holds excellently in vacuum service upto 760 mm of Mercury in vacuum.
Impervious graphite dilution coolers and evaporators acid tees, pipes, lined pipes, insets, lugs and graphite filled repair cements.
2. ALLOY STEEL AND STAINLESS STEEL INDUSTRY:
Impervious Carbon bricks and cements are used for lining of pickling tanks where concentrations of hydrofluoric, nitric, Sulphuric and hydrochloric acid are used in varying proportions upto 900C for descaling of steels.
3. HEAVY CHEMICALS, PESTICIDES AND DYE STUFF INDUSTRY :
Carbon bricks, tiles and cements for lining of reactors, vats and intermediate Paddle mixing vessels where abrasion is envisaged. It is a good substitute lining where silica brick lining, F.R.P., rubber lining S.S. etc. fail frequently causing Plant shut downs and consequent production loss.
Impervious Graphite pump spares, rupture discs, cements, carbons raschig rings, Tower lined internals and gas chambers.
4. WATER TREATMENT PLANTS:
In acid dilution tanks while mixing sulphuric and hydrochloric acid where heat is generated to 1650C. This causes severe thermal shocks causing spalling of other Plastic linings and failure of lead linings which is generally used today for this duty purpose.
Available sizes shapes
- 230 X 115 X 75 MM Thk
- 230 X 115 X 65 MM Thk
- 230 X 115 X 40 MM Thk
- 230 X 114 X 30 MM Thk
- 230 X 65 X 25 MM Thk
- 230 X 65 X 20 MM Thk
- 230 X 65 X 12 MM Thk
Any special shapes & Sizes can be made as per customer request