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Tank furnace

PROCESS DESCRIPTION

Raw materials of batch generally stored in silos. The major component are sand, glass cullet and frit, minor components are Borax, Dolomite, Alumina Hydrate, Limestone. Based on the recipe these components charged into the mixer in a pre-defined order to eliminate separation. The mixed batch than transported to the batch charger – usually pusher or screw type – next to the furnace. The batch is melted at temperatures of 1380 - 1450°C in a tank furnace what can be all-electric, air-fuel or oxy-fuel fired, with or without electric boost. Melted material is conditioned in a refiner on 1150 - 1200 °C before distributed to the fiberizers through the forehearth / feeder channels (1120 - 1175 °C).

GAS APPLICATION

Oxy-Fuel Burners for Tank

The fuel is fired without nitrogen in the applied oxidant (pure oxygen) (lower volumes of flue gases, less diluted) with oxygen quality >90%.

In general, oxy-fuel glass furnaces have the same basic design as recuperative glass melters, with multiple lateral burners and a limited number of exhaust port(s).Typically are only 4 to 6 burners per sidewall installed.

Burners from opposite sidewalls are preferably not placed in one line, but staggered in order not to produce hot spots. A complete oxy-fuel furnace is approximately 25-30% cheaper in comparison to an end fired furnace, and approximately 15-20% cheaper in comparison to a recuperative furnace.

Oxy-fuel melting can be a very effective technique for NOx abatement (see COMMISSION IMPLEMENTING DECISION of 28 February 2012 establishing the best available techniques (BAT) conclusions under Directive 2010/75/EU of the European Parliament and of the Council on industrial emissions for the manufacture of glass).

In case of economy and improvement of emission pollution pure oxy fuel can be applied. Replacement of regenerative firing by oxyfuel burners result in:

  • App. 10 - 20% total fuel saving
  • Better working environment – less noise, less heat from furnace
  • No regenerator required.
  • Lower emissions – NOx (-50%), CO2, particulates
  • Lower emissions (particulates, NOx, HF, HCl …)
  • Less heat loss through the exhaust system
  • Less batch loss by the lower exhaust velocity, less dust emission
  • The capacity of electrostatic precipitator can be reduced by 75%
  • Flue gas channel area can be reduced
  • Faster and more consistent melting; flexibility
  • Better glass quality
  • No significant capital investment required 

Furnace type

Endfired Reg.

Oxy-Fuel

Glass Type

E-Glass

E-Glass

Area (m²)

100%

100%

Daily production (t/day)

100%

133%

NOx emission (kg/t)

100%

40%

Specific energy (kcal/kg melt)

100%

81%

Offgas Volume (Nm3/h)

100%

26%

Operational Data comparison

Oxyfuel Burners - Feeder

If the energy consumption of the melter + refiner/distribution channel + feeder is assumed at 100%, then the ratio of energy consumption of a feeder depends on the glass temperature entering it and length of the feeder. In general this value is between 20 – 50%.

The results of applying oxyfuel burners at feeders are:

  • Lower fuel consumption (up to -60%)
  • Lower emissions (up to -80% NOx)•
  • Better heat transfer by the 3 atom molecules taking place in the combustion - better heat distribution
  • Improved temperature regulation and homogeneity of the glass
  • Improved glass quality
  • Low maintenance
  • No blowers required for the combustion
  • Faster responses
  • Increased glass throughput
  • Longer superstructure refractory life with volatile glasses
  • Higher turndown ratios
  • Option to switch off burners without a risk of back firing

Messer Solution

Oxipyr Burners:

Oxipyr - F

Oxipyr - F micro

Oxipyr - Flat

Oxipyr - Flex3

Oxipyr - P / P LON

Oxipyr - Burner Regulation:

Oxipyr - Advanced regulation

Oxipyr - Basic+, Basic regulation

Oxipyr - 400 regulation