Apparatus and method for treating gas discharged from cement kiln

Abstract

[Subject] To suppress heat energy loss and generation of organic contaminants, and efficiently recover heavy metals contained in chlorine bypass dust when treating gas extracted from a cement kiln exhaust gas passage. [Means for Solution] A cement kiln exhaust gas treatment device 1 comprising: a probe 42 for extracting a part of combustion gas from a kiln exhaust gas passage running from an inlet end of a cement kiln 41 to a bottom cyclone; a cyclone 44 for classifying a coarse powder D1 from the extracted gas G1; a high-temperature bag filter 2 with heat resistance of 300°C or higher for solid / gas separating an exhaust gas G2 containing a fine powder D2 discharged from the cyclone 44, and others. With this, it becomes unnecessary to cool the extracted gas during gas treatment, which allows heat energy loss to be suppressed, and during the period until the dust is removed in the solid / gas separator 2, a temperature exceeding recomposition temperature of dioxins is maintained, which makes it possible to restrain the recomposition of dioxins.

Description

[0001] This application is a branch of an invention patent application titled "treatment device and method for cement kiln exhaust gas", the international application date is June 5, 2009, the international application number is PCT / JP2009 / 060338, and the national application number is 200980123075.6 case application. technical field [0002] The present invention relates to an apparatus and method for treating gas extracted through a kiln exhaust flow path from the furnace tail of a cement kiln to the lowest-stage cyclone. Background technique [0003] In the past, among chlorine, sulfur, alkali, etc. that have caused problems such as clogging of the preheater in cement manufacturing equipment, especially when chlorine is a problem, using a cyclone that passes from the tail end of the cement kiln to the lowest stage A chlorine bypass system that pumps a part of the combustion gas and removes chlorine from the kiln exhaust flow path of the device. [0004] This chlorine byp...

AI Technical Summary

Problems solved by technology

Therefore, the concentration of heavy metals in chlorine bypass dust increases, and if it is added to cement, there is a problem that there is a possibility that it may exceed the regulatory value

In addition, there is a risk of leaching of these heavy metals from concrete made from cements containing concentrated heavy metals

In addition, since the concentration of heavy metals in the wastewater washed with water and filtered of chlorine bypass dust increases, a large amount of chemicals are required for wastewater treatment, and there is a problem of high running costs.

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