Waste heat boiler

Abstract

A waste heat boiler includes an axial bypass pipe and multiple heat transfer pipes disposed within a cylindrical jacket. A hot exhaust gas stream transported between inlet and outlet ends of the heat transfer pipes is cooled by a coolant. A control system controls gas passage velocity and quantity of the exhaust gas stream through the bypass pipe whereby the exhaust gas stream exhaust temperature is maintained within a predetermined temperature range. The control system includes a stopper disposed at the outlet end of the bypass pipe and has a head plate extending into the outlet end of the bypass pipe. The stopper is axially displaceable from a closed position, where an outer surface of the stopper head plate contacts an inner surface of the bypass pipe outlet end. The gas passage formed between the inner surface of the bypass pipe outlet end and the outer surface of the stopper head plate has a cross-section that increases as the stopper is axially displaced from the closed position.

Description

technical field [0001] The invention relates to a waste heat boiler comprising a plurality of heat transfer tubes and a centrally located bypass tube in a cylindrical housing, each having an inlet port and an outlet port and including a regulating device for exhausting the waste heat boiler The temperature is kept within a certain temperature range. The present invention particularly relates to a waste heat boiler. In order to control the exhaust temperature of the waste heat boiler, its regulating device is installed on the outlet end of the bypass pipe. Background technique [0002] For many chemical and petrochemical processes, waste heat boilers require the flow of different gaseous and / or liquid media through the tubes and shell faces (channel side). Here, the high-temperature exhaust gas from the working process is usually fed to heat transfer tubes and bypass tubes which are arranged as tube bundles in the shell of the waste heat boiler. When the high-temperature ex...

AI Technical Summary

Problems solved by technology

In the control plugs currently used, there is the disadvantage that the exhaust gas flowing out of the open bypass line outlet forms a strong strand (Ströhne), which leads to the risk of hot spots on the exhaust chamber wall

One or more of these hot spots cause thermal damage to the exhaust chamber wall, which in turn leads to undesired shortened maintenance intervals and reduced waste heat boiler life

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