Method for treating ash deposition and scaling of GGH (gas-gas heater)

Abstract

The invention discloses a method for treating ash deposition and scaling of a GGH (gas-gas heater). The method for treating ash deposition and scaling of the GGH has the advantages that the steps of blowing ash online by compressed air, flushing online by high-pressure water, flushing by low-pressure water before halting and performing high-pressure flushing by chemical cleaners after halting are adopted, so that the problems of severe ash deposition and scaling of a heated surface of the GGH due to ash deposition, acid coagulation, liquid drop adhesion and the like are solved, blockage resulting from ash deposition and scaling of the GGH is slowed down substantially, normal operation and flue gas desulfurization effect of a desulfurization system are guaranteed, halting times of the desulfurization system are decreased, and safety operation and safety economy of a unit are guaranteed under a rated condition.

Description

technical field [0001] The invention relates to the field of flue gas heat exchangers, in particular to a method for treating the soot and fouling of the flue gas heat exchanger GGH. Background technique [0002] In the desulfurization system (FGD), in order to prevent the low-temperature wet flue gas discharged from the absorption tower from corroding the flue and the inner wall of the chimney, and at the same time increase the lifting height of the flue gas discharged from the chimney to facilitate the diffusion of pollutants and avoid falling droplets of the exhaust gas, the permanent flue gas Heat exchanger (GGH) unit. In the flue gas reheater rotor, the heat transfer elements are closely arranged in the basket frame, and the heat transfer elements have certain flow channels, and the raw flue gas and the clean flue gas pass through the flow channels of the heat transfer elements. When the rotor rotates to the raw flue gas side, the heat transfer element absorbs the heat...

AI Technical Summary

Problems solved by technology

[0005] (2) The effect of the demister is poor: the demisting effect of the demister at the outlet of the absorption tower is not good, or the gypsum deposition of the demister element narrows the channel, resulting in the saturated wet flue gas carrying gypsum slurry

[0006] (3) GGH purging or flushing is abnormal: GGH purging and flushing equipment has a high failure rate, nozzle blockage, flushing pressure and flushing frequency are unreasonable, etc. cannot remove ash in time, and ash accumulation increases the cumulative thickness, eventually causing blockage

[0007] (4) Other reasons: when the pH value in the absorption tower is high, the CaSO carried by the flue gas 2 The content is also high, and they are related to the SO in the original and clean flue gas 2 Continue to react to form crystalline gypsum, which firmly adheres to the GGH heat exchange element and causes blockage