Modular system and method for the catalytic treatment of a gas stream

Abstract

A system for catalytically treating a gas stream includes a gas phase reactor containing a catalyst for the treatment of the gas stream in at least one catalyst bed having an upstream end and a downstream end, an axial fan positioned upstream of the at least one catalyst bed and having an impeller for moving the gas stream through the gas phase reactor. The gas flow is modified between the impeller and the gas phase reactor to decrease gas stream velocity and increase gas flow uniformity.

Description

CROSS REFERENCE TO RELATED APPLICATION(S) [0001] The present application is a Continuation of co-pending U.S. application Ser. No. 09 / 973,401 filed Oct. 9, 2001, to which priority is claimed and which is herein incorporated by reference.BACKGROUND [0002] 1. Field of the Invention [0003] The invention herein relates to a system and method for catalytically treating a gas stream, and particularly to a system and method for catalytically reducing the content of undesirable compounds in a flue gas resulting from the combustion of fuel. [0004] 2. Description of the Related Art [0005] Catalytic treatment for modifying the composition of gas streams is well known in the art. Various types of catalyst beds have been used such as fixed beds and fluid beds. Among fixed beds there are axial flow reactors, radial flow reactors and parallel flow reactors. [0006] Environmental concerns and new regulations are motivating further research and development in the treatment of gas streams to reduce th...

AI Technical Summary

Benefits of technology

[0013] c) gas flow modification means positioned between the impeller and the gas phase reactor for decreasing gas stream velocity and increasing gas flow uniformity.

[0014] The system advantageously provides increased efficiency by rendering the velocity profile of the gas stream more uniform before it enters the reactor and preventing uneven flow through the catalyst bed. Furthermore, the uniformity of the composition of the gas stream is also increased.

Problems solved by technology

One problem associated with the catalytic treatment of large volumes of gas is providing an even distribution of the gas across the face of the catalyst, and an even mixing of the flue gas with the reducing agent.

As can be readily appreciated, uneven distribution reduces the efficiency of the system.

However, because of the physical bulk of the deNOx / deSOx systems, the flue gas must be diverted to ground level for treatment and then sent back to the stack for subsequent exhaust to the atmosphere.

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