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MECHANICAL METHOD OF REMOVING FOAM LAYER FROM MELT SURFACE OF OXY-FUEL FIRED GLASS MELTING FURNACES

IP.com Disclosure Number: IPCOM000199522D
Publication Date: 2010-Sep-07
Document File: 5 page(s) / 256K

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Title:  Mechanical method of removing foam layer from melt surface of oxy-fuel fired glass melting furnaces

Summary of the Invention:

A mechanical method for removing foam layer from melt surface of oxy-fuel fired glass-meting furnaces is invented. The new system includes vacuum pumps, filters, and water-cooled steel pipes. The steel pipes cooled by water are stretched into the furnace from both side walls, which are crossed part of furnace width few millimeters above the top surface of foam layer which is floating on glass melt surface. The pipes could be located at anywhere in front of batch coverage.  The vacuum pump extracts the foam out off the furnace through the piping. When the most part of the foam is removed from the melt surface, the furnace crown temperature will reduce 50K to 100 K. Therefore, a large amount of energy saving will be obtained and the furnace lift will be increased. Heat transfer from combustion space to glass surface, oxy-fuel fired furnace thermal efficiency and glass melt quality will be improved significantly.

Field of the Invention

The present invention relates to a mechanical method of removing foam layer from melt surface of oxy-fuel fired glass-melting furnace by using vacuum pumps, filters, and steel pipes, which improves heat transfer from combustion space to glass surface, furnace thermal efficiency, and glass melt quality.

Description of the Prior Art

The oxy-fuel firing improves combustion, reduces NOx, CO2 and total fuel input. Therefore, many glass-melting furnaces have been switched to oxy-fuel firing system from traditional air-fuel firing system since 1990s.

Gases are released from raw materials and molten glass during batch melting and glass refining process in glass-melting furnaces, which forms a foam layer on the batch and glass surfaces. In air-fuel fired glass-melting furnaces, the foam layer is located at the end of batch area which covers part of melting surface. In oxy-fuel firing glass-melting furnaces, a thick foam layer on glass melt surface is created [1, 2] and it may cover almost all melting surface and large part of refining surface. Heat transfer coefficient of the foam layer is very low [3]. Therefore, the foam layer acts as an insulating layer for the heat transfer from the combustion space to the glass melt. The foam layer increases furnace flame temperature, increases refractory corrosion and reduces furnace life. For keeping desired melting and refining temperature, more fuel is consumed in the furnace. Based on the Computational Fluid Dynamics modeling prediction for a glass melting furnace, the crown temperature will increase 50 K to 100 K when a 25.4 mm thickness foam layer covers on the meting and refiner area for a container glass melt [4]. Research work reported that the foam might be a dominant mechanism for the introduction and/or retention of glass defects [5]. Therefore, the glass melt quality is impacted by large and thick foam layer formed on the melt surface in...