Ash and solids cooling in high temperature and high pressure environment

摘要

Disclosed are cooling and depressurization system equipment, arrangement and methods to cool solid particles from a coal gasifier operating at high temperature and pressure. Ash needs to be continuously withdrawn from a circulating fluidized bed gasifier to maintain the solids inventory in the gasifier. The supports for the cooling surfaces are located on the lower temperature upper section of the primary cooler. The cooled solids along with the fluidizing gas exits the primary cooler to a secondary receiving vessel where the solids can be further cooled by conventional means. The fluidizing and entrained gas entering the secondary vessel is filtered and vented through a vent pressure control valve. The column of cooled solids in the secondary vessel is depressurized by a continuous depressurization system to low pressures which are sufficient for conveying the solids to silos for disposal.

主权项

1. A system of cooling ash and solids from high temperature and high pressure coal gasification environment, the cooling system comprising:
a gasifier; a primary solids cooler; a downcomer connecting the gasifier and the primary solids cooler, and introducing the solids to the bottom of the primary solids cooler; a heat transfer system in the primary solids cooler to exchange heat between the solids and a cooling medium; a support in proximity of the top of the cooler for supporting the heat transfer system; a solids outlet in proximity of the top of the primary solids cooler and below the support; a secondary cooler; a gas-solids separation system at an inlet of the secondary cooler; a vent filter section in proximity of the top of the secondary cooler to limits solids over a predetermined size from entering a vent line; a pressure control vent valve to control the pressure difference between the primary solids cooler and the gasifier; and a continuous pressure letdown system, wherein the cooled solids are withdrawn from the secondary cooler through the continuous pressure letdown system that reduces the solids stream pressure to a desired level for conveying from the secondary cooler.