METHOD AND FACILITY FOR MANUFACTURING CROSS-LINKED FIBERGLASS MATERIAL

Abstract

The invention relates to a method and facility for manufacturing a cross-linked fiberglass material, in which melted glass is produced in a melting furnace heated via combustion of a fuel with an oxygen-rich oxidant. The melted glass is converted into glass filaments, the filaments are bonded, a sheet is made from the bonded filaments, and the sheet is then cross-linked. The fumes from the melting furnace are used to preheat a combustion reagent in two steps: a first step in which air is heated via heat exchange with the fumes, and a second step in which the combustion reagent is preheated via heat exchange with the hot air. The air is then used in the cross-linking step of the method for converting the melted glass into a fiberglass material.

Claims

1. A plant comprising a glass melting furnace and a conversion unit for the conversion of molten glass into a glass fiber product, the melting furnace comprising a molten glass outlet, an outlet for flue gases and at least one burner for the combustion of a fuel with a rich oxidizer having an oxygen content of 80 vol % to 100 vol %, the conversion unit comprising: a bushing for the spinning of molten glass resulting from the melting furnace into at least one stream, said bushing being fluidically connected to the molten glass outlet of the furnace; an attenuation device for the attenuation of at least one stream resulting from the bushing into one or more filaments; a collector for the collecting of the filament or filaments resulting from the attenuation device; an adhesive applicator for the application of adhesive (binder) to the filament or filaments upstream of or after the collection; and a crosslinking chamber for the crosslinking of the adhesive-treated collected filament or filaments, wherein: the plant further comprises a heat-exchange assembly for the heating of air by heat exchange with flue gases discharged from the furnace and for the preheating of a combustion reactant by heat exchange with the hot air, with preheated combustion reactant and moderated air being obtained; the heat-exchange assembly is fluidically connected to a source of air, to the flue gas outlet of the furnace and to a source of a combustion reactant chosen between rich oxidizer and gaseous fuel; and the heat-exchange assembly includes a preheated combustion reactant outlet fluidically connected to the burner of the melting furnace and also a moderated air outlet fluidically connected to the crosslinking chamber in order to promote the crosslinking of the adhesive-treated filament or filaments by contact with moderated air resulting from the heat-exchange assembly.

2. The plant of claim 1, wherein the heat-exchange assembly comprises a primary exchanger for heat exchange between the flue gases discharged from the furnace and the air and a secondary exchanger for heat exchange between the heated air resulting from the primary exchanger and the combustion reactant.

3. The plant of claim 1, wherein the collector comprises a conveyor for transporting the filament or filaments collected in the form of a glass fiber fleece toward the crosslinking chamber.

4. The plant of claim 3, wherein the adhesive applicator is located upstream of the conveyor so as to make possible the application of adhesive to the filament or filaments before they are transported in the form of a fleece by the conveyor.

5. The plant of claim 1, wherein the conveyor is gas permeable and in which the crosslinking chamber comprises one or more suction devices for sucking moderated air resulting from the heat-exchange assembly through the glass fiber fleece and the conveyor inside the crosslinking chamber.

6. The plant of claim 1, comprising a shaping unit downstream of the crosslinking chamber for the production of acoustic insulation and/or thermal insulation and/or fire-protection products from the crosslinked fleece.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0116] FIG. 1 is a diagrammatic representation of a process and of a plant for the manufacture of a thermal insulation/acoustic insulation and/or fire-production fleece.

DETAILED DESCRIPTION OF THE INVENTION

[0117] The plant illustrated in FIG. 1 comprises a glass melting furnace 10 heated by a number of burners 12 (just one burner is shown in FIG. 1). To this end, rich oxidizer 28a, typically a gas containing between 95 vol % and 100 vol % of oxygen, and a gaseous fuel 29a, such as natural gas, are supplied to said burners 12.

[0118] The flue gases or combustion gases generated by the combustion of the fuel 29a with the rich oxidizer 28a are discharged from the melting furnace 10 and introduced into a primary exchanger 20 in order to heat the compressed air 24 supplied by the compressor 23. Downstream of the primary exchanger 20, the flue gases are discharged through the chimney 11, typically after having been subjected to a treatment for removal of pollutants. The hot air 25 resulting from the primary exchanger 20 is introduced into a first secondary exchanger 21 for the preheating of the rich oxidizer 28a and subsequently, in the form of partially moderated air 26, into a second secondary exchanger 22 for the preheating of the gaseous fuel 29a. The preheated rich oxidizer 28b resulting from the first secondary exchanger 21 and the preheated gaseous fuel 29b resulting from the second secondary exchanger 22 are supplied to the burners 12 as combustion reactants.

[0119] This makes possible a first very significant saving in energy in the manufacturing process according to the invention.

[0120] The molten glass resulting from the melting furnace 10 is introduced in the form of a stream of molten glass into a centrifuge 34 and the filaments resulting from the centrifuge 34 are attenuated by means of an annular current of attenuation gas generated by the crown-shaped attenuation burner 31.

[0121] The filaments resulting from this attenuation assembly are treated with adhesive by the sprayers 32 of the binder 35 and subsequently dried by jets of gaseous drying agent 36 injected by the dryers 33.

[0122] The stages of drawing, of application of adhesive and of drying are carried out in a controlled environment inside a hood 30.

[0123] The dried adhesive-treated filaments are collected in the form of a fleece 44 of filaments by a conveyor 42 at the bottom of the hood 30.

[0124] The conveyor 42 brings the fleece 44 toward a crosslinking oven 40 in which the adhesive-treated filaments are crosslinked under the effect of heat and thus binds the filaments together. Downstream of the oven 40, the rigid, semirigid or flexible fleece is shaped and wrapped up.

[0125] According to the invention, the residual heat present in the moderated air 27 resulting from the secondary exchangers 21, 22 is made use of in order to improve the energy efficiency of the conversion process downstream of the melting furnace 10.

[0126] Thus, a final portion of the moderated air 27 is introduced into the crosslinking oven and sucked through the fleece 44 inside the oven in order to promote the crosslinking of the filaments in the fleece 44.

[0127] Another portion of the moderated air 27 is used as drying gas 36 by the dryers 33, the residual heat of the moderated air 27 making it possible to accelerate the drying of the filaments.

[0128] In the embodiment illustrated, a final not insignificant portion of the moderated air 27 is introduced as oxidant into the attenuation burner 31 in order to more efficiently generate the attenuation gas current.

[0129] The advantages of the present invention will be better understood in the light of the following example.

[0130] The melting furnace produces 100 tpd of insulating fiber from 5 MW of thermal power. A contribution of electrical energy of the order of 1 to 5 MWe may be necessary according to the production conditions. The combustion flue gases exit at 1350° C. and can be cooled by dilution to reach a temperature of 1200° C. at the inlet of the primary exchanger. The 500 Sm.sup.3/h of natural gas (95% methane, 2% butane, 2% propane and 1% CO.sub.2) are preheated to 450° C. The 1000 Sm.sup.3/h of oxygen are preheated to 550° C. In order to preheat these gases, close to 4000 Sm.sup.3/h of air are necessary. Heated to 650° C. in the primary exchanger, the air is cooled to 400° C. at the outlet of the secondary exchangers.

[0131] This air, which has an energy value of 530 kW, is subsequently conveyed, in a pipe preferably made of stainless steel, toward the crosslinking chamber. By virtue of this hot air, the amount of fuel is significantly reduced (10%). Additional fresh air can be supplied in the downstream part of the chamber for more exhaustive drying.

[0132] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0133] The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

[0134] “Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”.

[0135] “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0136] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0137] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

[0138] All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.