Submerged combustion melters and methods of feeding particulate material into such melters

Abstract

Methods of melting particulate feedstocks in a submerged combustion melter employing an arrangement of one or more submerged combustion burners emitting combustion products into turbulent molten material. Operating the burners such that there is established a turbulent melting region extending vertically from the floor to a splash region, the splash region extending vertically between the turbulent melting region and a head space region, the head space region extending vertically between the splash region and the melter ceiling, the ceiling positioned above the floor a height H2. Feeding the particulate feedstock into the splash region through one or more inlet ports, the inlet ports positioned at a height H1 measured from the floor, where H1 / H2 ranges from about 0.33 to about 0.67. The SCM may have a baffle extending from the ceiling into the splash region. A particulate feedstock conduit may be employed, having an exit port in the splash region.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is a division of pending U.S. application Ser. No. 15 / 293,463 filed Oct. 14, 2016, the entire disclosure of which is hereby incorporated by reference herein.BACKGROUND INFORMATIONTechnical Field[0002]The present disclosure relates generally to the field of submerged combustion melters and apparatus, and methods of use, and more specifically to submerged combustion melters, and methods of operating same, particularly for melting glass-forming materials, mineral wool and stone wool forming materials, and other predominantly non-metallic inorganic materials.Background Art[0003]A submerged combustion melter (SCM) may be employed to melt glass batch and / or waste glass materials (including waste glass materials that have an organic coating) to produce molten glass, or may melt mineral wool feedstock (basalt rock, sometimes referred to as lava rock) to make mineral wool, by passing oxygen, oxygen-enriched mixtures, or air along w...

AI Technical Summary

Benefits of technology

The present patent discusses methods and systems for improving the mixing of particulate feed materials in a melting process of non-metallic inorganic materials. This can be done by feeding the particulate feed materials into a specific region of the melting process, called the splash zone, to create a more homogeneous melt and reduce feedstock loss through exhaust. The technical effects include higher quality and more efficient production of non-metallic inorganic materials.

Problems solved by technology

The introduction of high flow rates of products of combustion of the oxidant and fuel into the molten material, and the expansion of the gases during submerged combustion (SC), cause rapid melting of the feedstock and much turbulence and foaming.

While aggressive mixing and turbulence are desired for reducing time to melt feedstock, this splashing (where molten material actually breaks away from the turbulent surface and travels upward and then falls back down into the vitreous mass by gravity, or strikes the ceiling or walls of the SCM and drips back down into the molten mass, or solidifies thereon) is problematic as it causes at least some of the particulate batch feed to be splashed to undesired areas within the SCM, and is thus wasteful and decreases melt quality.

What the present inventor has discovered, however, is that the aggressive movement of the molten vitreous material causes even more violent splashing than previously recognized, causing some of the particulate materials to reach undesired areas of the SCM, such as the ceiling, reducing residence time and / or not allowing for a homogeneous melting of raw materials.

Some of the batch or other particulate material may also become entrained in the exhaust gases causing additional waste.

While some of this may be recycled to the feed, it is inefficient from an energy standpoint.

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