Asphalt Mixing Plants

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Filter media in asphalt mixing plants are exposed to extreme environmental conditions and aggressive corrosive gases. Temperature fluctuations and frequent start- ups and shut-downs with different fuels as well as the resulting potential of sparks put additional strain on the filter media. Depend upon the operating conditions and dust composition, Supertech Fabrics offers technically and economically optimal filter media solution for de dusting your asphalt mixing plant.

TYPICAL OPERATING CONDITIONS:

  • Cont. 100-200°C
  • Temperature (°C):
  • Peak Orientation to the maximum peak temperature of the fiber polymers used
  • Temperature (°C):
  • Dust: Asphalt, Minerals
  • Dust Properties: Abrasive
  • Dust Source: Dryer, Mixer, Rotary Kiln
  • Harmful Gases: NOx, So
  • Cleaning Process: Pulse Jet
  • Fuels: Bio Gas, Fuel Oil, Heavy Oil, Liquid Gas, Natural Gas, Pulverized Lignite

SPECIFIC REQUIREMENTS FOR FILTER MEDIA IN ASPHALT MIXING PLANTS:

  • Robust filter media
  • Continuous temperature resistance up to 200°C
  • Resistant to occasional high temp. upsurge

Cement Mill

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Generally ball mills are used for clinker grinding, additives like limestone, pond ash, fly ash, gypsum, and slag are added depending upon the grade of the cement. Now vertical raw mills are also in use for grinding the clinker.

Operating Data-

  • Bag filter is used for venting of Mills.
  • Dust Handled: Cement Dust
  • Design Temperature: 135 deg C for Polyester and 125 deg C for Acrylic
  • Surge Temperature: 140 deg C for Acrylic and 150 deg C for Polyester
  • Dust Load: 30-600 g/Nm

Problem with conventional filter bags-

  • frequent choking of filter bags
  • High bag house pressure drop
  • Unable to handle larger air flow and production rate
  • Increase maintenance and emissions.

Solution-The only solution is Supertech ePTFE membrane lamination on conventional felt.

Filter Media Used In Cement Mill-

1) Polyester Needle Felt

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Generally ball mills are used for clinker grinding, additives like limestone, pond ash, fly ash, gypsum, and slag are added depending upon the grade of the cement. Now vertical raw mills are also in use for grinding the clinker.

Fabric Treatments We Do:inged, Glazed, Oil, and water repellent finish. Polyester felt with PTFE membrane lamination is also available. Alternatively, microfiber finish is available to lower emissions. We at Supertech do membrane lamination on Polyester needle felt. Polyester also used with antistatic fibers in coal mill application.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Excellent
  • Acid Resistance- Poor
  • Alkali Resistance- Poor
  • Hydrolysis- Poor
  • Max Continuous Temperature- 135 Deg C

Applications-

  • Cement: Finish Mills, Separators, Bulk Pneumatic Conveying, Bin Vent Dust Collectors,Mines.
  • Nuisance Dust Collectors in Chemical Plants
  • Power: Material handling for coal and limestone
  • Polyester has the widest range of application in pulse jet bag filter.

2) Homopolymer Acrylic Needle Felt-

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Used when Moisture is high.

  • Homopolymer acrylic has very good hydrolysis and acid resistance.
  • Acrylic felt is commonly used as an alternative to Polyester for protection against hydrolysis problems.
  • Blends of acrylic and polyester with lower hydrolysis and acid resistance are also available to use in cement mills.
  • Treatments Available: Heat-set, Calendared, Oil & Water Repellency, PTFE Dispersion
  • Acrylic with PTFE membrane lamination available to increase the flow rate through the bag house as well as to lower bag house emissions.
  • Anti-Static version of this felt is generally used in Coal Mill Application.

Mechanical and Textile Properties-

  • Tensile Strength- Good
  • Abrasion Resistance- Good
  • Acid Resistance- Very good
  • Alkali Resistance- Poor
  • Hydrolysis- Very good
  • Max Continuous Temperature- 125 Deg C

Applications-

  • Cement Mill and Coal Mill
  • Lime Kilns at Steel Plants
  • Asphalt Industries.

Coal Mill

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Two types of coal firing are used:

1.Direct Firing
2. Indirect Firing.
Direct firing is when coal is milled and is directly fed to the kiln.
In indirect firing system, coal is milled and stored and fed to the kiln as needed. Most new plants have indirect firing.

Operating Data-

  • Nature of dust: Explosive, Free Flowing
  • Dust Load: 30-500 g/Nm3
  • Design Temperature: 135 deg C for Polyester and 125 deg C for Acrylic
  • Surge Temperature: 140 deg C for Acrylic and 150 deg C for Polyester
  • Coal fineness has a direct relationship with its reactivity.

Problem with conventional filter bags-

  • High-moisture present in fuel
  • Increased pressure drop
  • High maintenance and lesser bag life

Solution-The only solution is Supertech ePTFE membrane lamination on conventional felt.

Filter Media Used In Cement Mill-

  • Polyester Neddle Felt
  • Homopolymer Acrylic needle Felt

Anti-static Polyester Felt-

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To reduce static chrarges in coal mill bag house we recommend to use antistatic treatment felt in bag house to prevent sparking and firing in the filter bag.
Various ways are available to use felt with antistaic property-


  • Blend of carbon yarn in the felt
  • Scrim of carbon in the felt
  • Grounding wire is added to the vertical stitching line during the bag manufacturing process.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Excellent
  • Acid Resistance- Poor
  • Alkali Resistance- Poor
  • Hydrolysis- Poor
  • Max Continuous Temperature- 135 Deg C

Applications-

  • Cement: Coal Mill Filter Bags in Cement Plants
  • Chemicals: Some dryer baghouses with very fine dust
  • Power: Coal handling collectors and coal milling baghouses
  • Polyester has the widest range of application in pulse jet bag filter.

Metals: Process venting and material handling dust collectors for pulverized coal

Anti-Static Homopolymer Felt-

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To reduce static charges in coal mill bag house we recommend to use antistatic treatment felt in bag house to prevent sparking and firing in the filter bag.

Various ways are available to use felt with antistaic property-

  • Blend of carbon yarn in the felt
  • Scrim of carbon in the felt
  • Grounding wire is added to the vertical stitching line during the bag manufacturing process.

Mechanical and Textile Properties-

  • Tensile Strength- Good
  • Abrasion Resistance- Good
  • Acid Resistance- Very good
  • Alkali Resistance- Poor
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 125 Deg C

Applications-

  • Cement- Coal mill bag house.

Klin/Raw Mill

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The raw mill grinds limestone, clay or shale into “Raw Mix”  which is then fed to kiln through preheater. As the mix travels through the rotary kiln, its temperature rises gradually. Flue gas generated in pyro-processing travels in a direction opposite to material flow. Kiln exit gases contain pollutants like SOx and NOx. At preheater outlet, flue gas temperature ranges around 350 Deg C and is brought down by inducing dilution air or water cooling when the Raw Mill is down.
High temperatures, combined with alkaline and acidic gases make selection of right filter media critical at this Important Bag house.

Operating Data-

  • Dust To be handled: Kiln/raw mill gases
  • Nature of dust: Fine, free-flowing, mildly abrasive
  • Typical Gas temperature: 90-240 Celsius
  • Typical Surge Temperature: 260 Celsius
  • Dust Load: 30-80 g/Nm3

Benefits of using Supertech make Membrane laminated fiberglass bags Reduce fan energy costs-

  • Increased bag life
  • Reduce equipment downtime & maintenance
  • Reliably meet emissions regulations
  • Better mill sweep, and less water spraying

There are two types of bag house used in cement industry for kiln/raw mill application-

Pulse jet bag house-In pulse jet bag house we recommend 750 gsm Supertech fiber glass woven fabric with membrane lamination,
Reverse air bag house- In reverse air bag house we recommend 350 or 450 gsm Supertech make fiber glass woven fabric with different coatings, like – SGT, PTFE, ACID RESISTANCE FINISH.

Pulse jet bag house-

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Reverse air bag house-

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For Reverse Air Bag House Application-

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350 GSM AR Fiber Glass With Membrane

The unique speciality of this filter fabric is to be able to withstand high temperatures (260°C) and acid gases which makes it ideal for Reverse Air Filters in Cement Kiln/Raw Mill bag houses.

  • This fabric generally comes in three finishes i.e.,
  • PTFE finish
  • Acid Resistant (AR- most commonly used and pictured here)
  • Older Silicon-Graphite-Teflon (SGT) finish

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Poor
  • Acid Resistance- Good
  • Alkali Resistance- Good
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Cement Kiln/Raw Mill
  • Carbon Black Filters
  • Ferroalloy, Iron, and Steel Plants
  • Tire incinerators, and coal-fired boilers

For Pulse jet With Temperature Upto 260 Deg C-

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750 GSM Fiber Glass With Membrane

  • The AR (acid resistant) finish on the fiberglass increases resistance to acidic gases in the dust.
  • Fiberglass filter bags are the first choice for higher temperature bag filter applications.
  • Fiber glass excellent tensile strength and resistance to hydrolysis.
  • PTFE membrane lamination is provided for better filtration efficiency and to reduce differential pressure.
  • Care should be taken on cage quality while using fiberglass filter bags.
  • Cage should have 18-20 nos vertical wires for fibergalss filter bags.
  • We also provide PTFE felt cuffs (750-850 gsm) at the top, bottom, and cage joints to improve bag life, emissions and prevent middle cgae joint to tear the fabric by abrasion.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Poor
  • Acid Resistance- Good
  • Alkali Resistance- Good
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Commonly used at the cement kiln/raw mill application.
  • Boiler and incinerators.
  • Carbon black main bag filter and purge bag filter.

For Pulse jet With Temperature Upto 240 Deg C

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P-84 Felt

  • Polyimide felt (P84) have quality to resist high abrasion resistance at high temperatures (240 deg C).
  • Multilobal P84 fibres create a low-velocity flow profile thereby increasing filtration efficiency and reducing pressure drop.
  • P84 provides better bag life in applications where Fiberglass is providing poor life due to abrasion-related failures. Fiberglass is highly fragile and over pulsing, excessive cleaning cycles, and high dust loads can lead to abrasion and membrane failures.

Mechanical and Textile Properties-

  • Tensile Strength- Very good
  • Abrasion Resistance- Excellent
  • Acid Resistance- Very good
  • Alkali Resistance- Poor
  • Hydrolysis- Very good
  • Max Continuous Temperature- 240 Deg C

Applications-

  • Cement: ESP-converted hybrid pulse jet filters at the raw mill For better life than fiberglass.
  • Power: Blend of P84 with PPS is often used in Boiler Application to increase filtration efficiency.

Carbon Black

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Carbon black is majorly produced by the incomplete combustion of oils in refractory lined vessels in a process known as the oil furnace process.It is a process-controlled industry and requires durable construction and efficient filter media. Bag filters play an important role in the overall production no matter what type of grade is produced. Technology advancements over the years have allowed plants to extend filter life while increasing production rates and decreasing equipment downtime.

Main Bag Filter-

  • Type of Filters: Pulse Jet & Reverse Air
  • Design Temperature: 230 ~ 260℃

Issues-

  • Premature failure resulting in expensive downtime & labour cost
  • High Pressure Drop
  • Failure due to chemical attack and temperature excursion

Solution-

The use of membrane bags is a proven means of increasing bag life and reducing premature bag failures at the same time allowing for increased production rates.

Dryer Filter-

  • Type of Filter: Pulse Jet 
  • Design Temperature: 190 ~ 260℃

Issues-

  • High moisture and acidic gases
  • Oil exposure to the filter surface
  • Failure due to chemical attack and temperature excursion

Solution-

Downtime can be reduced and filter life can be increased by using 100% PTFE Felt bags in the dryer baghouse where the common operational issues are moisture, acid attack, and higher temperatures excursions.

Filter Media Used-

750 gsm AR fiberglass with Membrane

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  • The AR (acid resistant) finish on the fiberglass increases resistance to acidic gases.
  • Fiberglass filter bags are the first choice for higher temperature industrial applications.
  • It has excellent tensile strength and resistance to hydrolysis.
  • PTFE membrane lamination is provided for better filtration efficiency.
  • Care should be taken on cage quality while using fiberglass filter bags.
  • You may opt for PTFE felt cuffs (750-850 gsm) at the top, bottom, and cage joints to improve bag life and emissions.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Poor
  • Acid Resistance- Good
  • Alkali Resistance- Poor
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Mostly used at the cement kiln/raw mill application.
  • Boiler and incinerators.
  • Carbon black main bag filter and purge bag filter.

100% PTFE FELT -

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Mostly used in moisture and acidic conditions

  • PolyTetraFluoroEthylene (PTFE) felt is an inert felt with excellent hydrophobic properties and resistance to chemical attacks with a 260°C maximum service temperature.
  • PTFE felt is designed to easily handle extreme conditions like high acid gas concentrations (HCL, H2SO4), high humidity, and chemically operative conditions.
  • However PTFE is very expensive material, should only be used when everything else fails.
  • It has very poor abrasion resistance hence a minimum of 20-vertical wire supported cage is recommended.
  • PTFE Felt with PTFE membrane lamination is also available to enhance filtration efficiency and to reduce differential pressure.

Mechanical and Textile Properties-

  • Tensile Strength- Good
  • Abrasion Resistance- Good
  • Acid Resistance- Excellent
  • Alkali Resistance- Excellent
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Medical, municipal, industrial, sewage sludge, biomass, and hospital waste incineration
  • Chemicals Processing: Dryer off gas filtration under chemically or thermally demanding conditions.
  • Titanium Oxide Production
  • Slica Production

Metal Industry

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In the metal industry the reliable reduction of emission in a variety of manufacturing processes has become an indispensable process. High air-to-cloth ratio and different harmful gas compositions (e.g. scrap recycling) can damage the filter media and affect the separation efficiency. Our filter media have excellent filtration properties and have been successfully used for dust removal in metallurgical production plants.

TYPICAL OPERATING CONDITIONS:

  • Cont. 40-250°C
  • Temperature (°C):
  • Peak Orientation to the maximum peak temperature of the fiber polymers used
  • Temperature (°C):
  • Dust: Coke and Coal Dust, Metal Oxides, Reaction Products, Sinter Dust
  • Dust Properties: Abrasive, Agglomerating, Electrostatically Charged, Fine, Pyrophoric
  • Dust Source: Converters, Cupolas, Cyclone, Drying, Dry Sorbent, Electric Arc Furnace, Foundry, Mill, Silo, Sinter Strand, Transport Station, FES System, GCP Area
  • Harmful Gases: H2O, HCl, NOx, SOx,
  • Cleaning Process: Pulse Jet, Reverse Air, Shaker Filter
  • Fuels: Coal, Coke, Pet Coke, Lignite, Natural Gas

SPECIFIC REQUIREMENTS FOR FILTER MEDIA IN ASPHALT MIXING PLANTS:

  • High abrasion resistance
  • Resistance to occasional sparks and pyrophoric dusts
  • Resistance to hydrolysis after quenching
  • Separation of fine dust
  • Suitable to handle very fine dust
  • In the area of steel production, such as in the de-dusting of furnaces or the suctioning of arc furnaces, static charge can enter the dust collector. Depending on the dust collector design, filter media are treated with an additional antistatic Property. Wherever there are abrasive dusts, such as steel dust or aluminum oxide, an additional Silicone-finish applied to the single fiber can protect fibers again moist heat condition & can reduce the mechanical stress on the filter media and thus significantly prolong the operational life.
  • Filter media made of needle felt or fiberglass fabric are particularly suitable for fine dust filtration. Owing to a laminated ePTFE membrane, very fine dust particles are already separated on the surface. Filter media thereby allow compliance with minimal dust emission limit values.

Coal Fired Power Plant

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Coal Is Fired in Boiler to generate heat from boiler. hot flue gases containing fly ash is passed through a baghouse to separate the flyash before allowing the flue gases into the atmosphere through the stack.

Operating Data-

  • Dust To be handled: Flue gases containing fly ash
  • Nature of dust: Fine, free-flowing, abrasive
  • Cleaning Mode: Online/Offline
  • Design Gas temperature: 140 to 160 degree Celsius
  • Design Surge Temperature: 180 to 200 Degree Celsius
  • Dust Load: 5-20 g/m3

Flue gas which is a mixture of many gases is obtained as the byproduct of the combustion process.  These gases are released into the atmosphere which is the root cause of many diseases such as asthma, lung cancer, heart attacks which indirectly leads to early death of living beings. The gases evolved during combustion mainly are Nitrogen dioxide, Carbon dioxide, Sulfur dioxide, water vapor and traces of oxygen.

Fabrics Used –

  • PPS FELT
  • P-84
  • WOVEN FIBER GLASS 750 GSM

These felt can be used with Supertech ePTFE membrane lamination for better filtration, less emission and reduce differential pressure.

PPS FELT-

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Most commonly used felt when O2 is low and the temperature is < 160 deg C. Temp should never exceed 190. Membrane is used if the frequency of steam tube leakages is high. With every steam tube leakage (moisture getting into bag filter), membrane bags recover easier in comparison without removal and manual cleaning. Polyphenylene sulfide (PPS), brand name Ryton or Procon ®, is a commonly used for boiler applications due to excellent resistance to moisture.

  • PPS has excellent resistance to both acids and alkalis. The media also has the ability to operate effectively on applications with O2 content up to 9%.
  • PPS works well in high moisture content applications and where dew point crossings are common. This media is suited for applications where emissions standards are tight.
  • Fabric Treatment: Signed, Glazed, Oil and water repellent & Membrane Lamination
  • Can be blended with P84 to increase filtration efficiency.PPS with PTFE membrane lamination is also available.

Mechanical and Textile Properties-

  • Tensile Strength- Very good
  • Abrasion Resistance- Excellent
  • Acid Resistance- Excellent
  • Alkali Resistance- Very good
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 190 Deg C

Applications-

  • Coal-fired Power Plants
  • Select MSW incinerators
  • Fluidized bed systems
  • Asphalt plants

P84 FELT-

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  • Polyimide felt (P84) have quality to resist high abrasion resistance at high temperatures (240 deg C).
  • P84 fibres create a low-velocity flow profile thereby increasing filtration efficiency and reducing pressure drop.
  • P84 provides better bag life in applications where Fiberglass is providing poor life due to abrasion-related failures. Fiberglass is highly fragile and over pulsing, excessive cleaning cycles, and high dust loads can lead to abrasion and membrane failures.

Mechanical and Textile Properties-

  • Tensile Strength- Very good
  • Abrasion Resistance- Excellent
  • Acid Resistance- Very good
  • Alkali Resistance- Poor
  • Hydrolysis- Very good
  • Max Continuous Temperature- 240 Deg C

Applications-

  • Cement: ESP-converted hybrid pulse jet filters at the raw mill For better life than fiberglass.
  • Power: Blend of P84 with PPS is often used in Boiler Application to increase filtration efficiency

For Pulse jet With Temperature Upto 260 Deg C-

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  • The AR (acid resistant) finish on the fiberglass increases resistance to acidic gases in the dust.
  • Fiberglass filter bags are the first choice for higher temperature bag filter applications.
  • Fiber glass excellent tensile strength and resistance to hydrolysis.
  • PTFE membrane lamination is provided for better filtration efficiency and to reduce differential pressure.
  • Care should be taken on cage quality while using fiberglass filter bags.
  • Cage should have 18-20 nos vertical wires for fibergalss filter bags.
  • We also provide PTFE felt cuffs (750-850 gsm) at the top, bottom, and cage joints to improve bag life, emissions and prevent middle cgae joint to tear the fabric by abrasion.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Poor
  • Acid Resistance- Good
  • Alkali Resistance- Good
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Commonly used at the cement kiln/raw mill application.
  • Boiler and incinerators.
  • Carbon black main bag filter and purge bag filter.

General Boiler Application

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There are many users, who have small capacity boilers in their factory with small qty of bags, These users mostly prefer FMS Or Woven fiberglass fabric as their filter bag media depending upon no of vertical wires in the cage.

Operating Data-

  • Inlet Temp- 180-200 Deg C
  • Emission at stack- 50 mg/nm3
  • Designed Differential Pressure- 120-150 mmWG
  • Cleaning Mode- Online/Offline
  • Purging Pressure- 3-5 kg/cm2 depending on filter media

Fabric Used-

750 GSM Fiber Glass With Membrane

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  • The AR (acid resistant) finish on the fiberglass increases resistance to acidic gases in the dust.
  • Fiberglass filter bags are the first choice for higher temperature bag filter applications.
  • Fiber glass excellent tensile strength and resistance to hydrolysis.
  • PTFE membrane lamination is provided for better filtration efficiency and to reduce differential pressure.
  • Care should be taken on cage quality while using fiberglass filter bags.
  • Cage should have 18-20 nos vertical wires for fibergalss filter bags.
  • Cage should have 18-20 nos vertical wires for fibergalss filter bags.
  • We also provide PTFE felt cuffs (750-850 gsm) at the top, bottom, and cage joints to improve bag life, emissions and prevent middle cgae joint to tear the fabric by abrasion.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Poor
  • Acid Resistance- Good
  • Alkali Resistance- Good
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 260 Deg C

Applications-

  • Commonly used at the cement kiln/raw mill application.
  • Boiler and incinerators.
  • Carbon black main bag filter and purge bag filter.

FMS FABRIC-

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FMS fabric is the good replacement of fiber glass fabric in term of properties of fiber glass and p84 because it contains fiberglass+p84 both. FMS used in huge qty in boiler applications with higher life and low maintenance cost.

Mechanical and Textile Properties-

  • Tensile Strength- Excellent
  • Abrasion Resistance- Good
  • Acid Resistance- Good
  • Alkali Resistance- Satisfactory
  • Hydrolysis- Excellent
  • Max Continuous Temperature- 250 Deg C

Applications-

  • Cement Plant- Clinker Silo
  • Boiler Bag Filter

Textile & Paper Industry

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Textile & paper industry mainly having boilers, in which fuel is coal, wood-chips, briquettes & other secondary fuels etc. & boiler works on high temperature, hence produced fumes having dust with sox, nox & other content, which need to be filter prior to dilute in atmosphere, Hence we offer filter media which is high temperature resistance & good for all type of gaseous conditions, also we can design filter media accordingly to the specific requirement.

TYPICAL OPERATING CONDITIONS:

  • Cont. 50-260°C
  • Temperature (°C):
  • Peak Orientation to the maximum peak temperature of the fiber polymers used
  • Temperature (°C):
  • Dust: Coal, fly ash
  • Dust Properties: Abrasive, chemically aggressive, explosive, fine, coarse, sticky
  • Dust Source: Boiler
  • Harmful Gases: SOx, NOx, volatile chemical substances
  • Cleaning Process: Pulse jet
  • Fuels: coal, secondary fuels

SPECIFIC REQUIREMENTS FOR FILTER MEDIA IN THE TEXTILE AND PAPER INDUSTRY:

  • High abrasion resistance
  • High separation efficiency
  • Good chemical resistance (in hydrolysis & oxidation conditions)

Address

Block No. 1401/A & 1401/B, Luna Patiya,
B/h. Elysium Pharma Mahali Talav,
Vil. Dhabasa, Tal. Padra, Dist. Vadodara,
Gujarat Pin Code: 391440. INDIA

Contact Us

Phone:
+91-2662-222036 / 222037
Email Id:
info@supertechfabrics.com

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