Combined batch and cullet preheater with separation and remixing

摘要

An improved method preheating cullet and glass batch together for use as feedstock for a glass furnace. The method uses a preheater including a separator and a heat exchanger. The heat exchanger is a direct contact raining bed in which large particles in the feedstock are heated by hot gases as the particles flow down by gravity and fine particles become entrained with the hot gas flow. The separator removes the fine particles entrained in the hot gases and remixes preheated the fine particles with the preheated cullet. Preheater systems are described in which the hot gasses are provided by the glass furnace exhaust, by a separately fired heater, by a separately fired heater combined with the glass furnace exhaust and by a separately fired heater with exhaust gas recirculation.