Gas distributor for fluidized bed coal gasifier

Abstract

The invention provides a gas distributor for a fluidized-bed coal gasification furnace, wherein a slag discharge pipe passes through the gasifier shell and communicates with the bottom of an inverted conical distribution plate; a ring pipe is arranged around the slag discharge pipe; The gasifier shell pipeline is connected to the ring pipe, and the lower part of the inverted conical distribution plate is provided with more than 3 through holes. , the cyclone return pipe passes through the gasifier shell and communicates with the conical distribution plate pipeline. The present invention innovatively changes the traditional structure of "central jet and annular pipe slag discharge" of the gasifier into a new structure of "central pipe slag discharge and annular pipe jet", and simultaneously removes the hot coal powder collected by the external cyclone separator. It is transported to the central high temperature zone in the gasifier to directly participate in the reaction, which greatly increases the gas production of the gasifier. The present invention can not only operate safely and stably for a long time, but also has high carbon efficiency, simple structure, low cost and simple operation, and is suitable for large Scale promotion and application.

Description

technical field [0001] The invention relates to the technical field of gas distributors, in particular to the technical field of gas distributors for gasification furnaces, and in particular to a gas distributor for fluidized bed coal gasification furnaces. Background technique [0002] In my country's natural resources, the basic characteristics are rich in coal, poor in oil, and little in gas, which determines the important position of coal in primary energy. Compared with oil and natural gas, my country's coal reserves are relatively rich, accounting for 11.6% of the world's reserves, making it the world's largest coal producer. The direct utilization of coal is not only inefficient, but also causes serious environmental pollution. In order to improve the efficiency of coal utilization and reduce environmental pollution, since the 1970s, the research and development of clean coal technology has arisen in the world. The core technology of clean and efficient utilization o...

AI Technical Summary

Problems solved by technology

This structure of "central jet flow, ring pipe slag discharge" has the following problems: (1) when the ash is discharged from the ring pipe, the high-temperature airflow entrains the ash and slag will scour the outer wall of the center pipe, which will eventually cause the center pipe to wear or break; in addition , the upper part of the slag discharge pipe is generally designed as a Venturi structure, and the Venturi structure is easier to be worn out than a straight pipe with the same upper and lower diameters; (2) The annular gap formed by the center pipe and the slag discharge pipe If the slag block or the internal lining of the gasifier shell falls off, it will block the ring pipe and affect the normal slag discharge of the gasifier; (3) The straight part of the center pipe is long. To prevent the center pipe from shaking, it is necessary to add support in the ring pipe If the support is directly washed by ash and slag, it will eventually fall off, causing the center tube to shake, and the center jet will deviate from the central area of ​​the gasifier, resulting in poor fluidization in the bed to form a dead zone, resulting in coking in the furnace

The disadvantages of this gas distributor are: (1) the upper surface of the conical distribution plate is easy to wear. The effect and the performance of the gas-solid two-phase reaction have a decisive influence. Since the surface of the conical distribution plate is easy to wear, the conical distribution plate will be worn through quickly, resulting in the use of the conical distribution plate and the gasifier. (2) The number of distributed injection pipes is at least 3, the number of openings in the gasifier shell will increase, and each injection pipe needs to be adjusted with a valve, which will increase the manufacturing cost of the gasifier; The gas volume of one injection pipe needs to be the same to ensure that the gas injected by all injection pipes can converge in the central area of ​​the gasifier, which requires that the valves of each injection pipe need to be adjusted synchronously to control the gas volume, which will increase the gasification rate. Difficulty of operating the furnace

The disadvantages of this gas distributor are: (1) There are at least three symmetrical gasification agent jet nozzles distributed on the pre-separation reducer, which is the same as the ash fusion fluidized bed gasification furnace disclosed in the above application number: 201210346022.4 The disadvantages of using a gas distributor (2) are the same; (2) the upper end of the inverted conical gas distribution plate is directly connected to the cylindrical gas chamber shell, and the high temperature in the gasifier will be transmitted to the gasifier shell through the inverted conical distribution plate body, causing the shell temperature to exceed the design temperature, and the coal gasifier belongs to class II or class III pressure vessel, the allowable stress of the plate will drop rapidly after the shell exceeds the temperature, there will be a danger of explosion, and there are serious safety hazards in the operation of the gasifier (3) The upper end of the slag discharge pipe is a pre-separation reducer, and the air flow and slag discharge under high temperature conditions lead to serious wear of the pre-separation reducer, making it difficult for the gasifier to operate for a long period

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