Industrial tail gas smoke dust and formaldehyde comprehensive treatment system and process

Abstract

The invention relates to an industrial tail gas smoke dust and formaldehyde comprehensive treatment process and system. The process mainly comprises the following steps that tail gas enters a cyclonedust remover to be subjected to primary dust removal; tail gas enters a quench cooler to perform heat exchange with circulation water; the circulation water enters a rear-end heater after the heat exchange; the tail gas enters a washing device; clean water is used for spraying; the sewage after spraying enters a sewage treatment system; the sewage after the treatment enters the washing device to be cyclically used; the tail gas enters an electric mist eliminator to be subjected to gas-liquid separation; the tail gas enters a heater to perform heat exchange with the circulation water; the circulation water enters a front-end quench cooler after the heat exchange; the tail gas enters a chimney through a smoke discharge fan. The system has the advantages that the cyclone dust remover, the quench coolers, the washing device, the electric mist eliminator and the heater are used for serial connection operation; the smoke dust and the formaldehyde in the industrial tail gas can be removed tothe maximum degree; meanwhile, a white mist phenomenon is eliminated. The operation and the management of the process are convenient; the investment and operation cost is low; no influence can be caused on the existing production process; good application prospects are realized in treatment of industrial tail gas containing the smoke dust and the formaldehyde.

Description

technical field [0001] The invention belongs to the field of industrial tail gas treatment, in particular to a system and process for comprehensive treatment of industrial tail gas dust and formaldehyde. Background technique [0002] In industrial production, especially in the density board production process, the industrial tail gas discharged contains a lot of smoke and formaldehyde. Smoke and dust will cause serious air pollution, inhalation of human body will cause various diseases, smoke and dust suspended in the air will reduce the visibility of the atmosphere and promote the formation of smoke; the concentration of formaldehyde reaches 0.1mg / m 3 Can cause discomfort to the human body, reaching 0.5mg / m 3 Can cause tearing, up to 0.6mg / m 3 It can cause throat discomfort, and when the concentration is higher, it will cause vomiting and even death; at the same time, the industrial tail gas discharged contains a large amount of water vapor, which will produce white fog i...

AI Technical Summary

Problems solved by technology

[0005] (1) The dust removal efficiency of the general-purpose cyclone dust collector is between 70% and 85%. Taking the density board production process as an example, after the industrial tail gas is dusted by the cyclone dust collector, the particle content is about 80-100mg / m 3 , unable to reach the limit value of 20mg / m3 stipulated in the "Petrochemical Industry Pollutant Discharge Standard" 3 , causing serious pollution to the environment

[0006] (2) The cyclone dust collector does not have the function of removing formaldehyde, so after the industrial tail gas is dedusted by the cyclone dust collector, the formaldehyde content does not change, and cannot reach the limit value of 5mg / m3 stipulated in the "Petrochemical Industry Pollutant Discharge Standard" 3 , will cause serious harm to the human body

[0007] (3) The cyclone dust collector does not have the function of removing water vapor, so the industrial tail gas still contains a large amount of water vapor after being dedusted by the cyclone dust collector, and white fog will occur in winter, causing visual pollution

This process can achieve the effect of removing soot and formaldehyde in industrial tail gas through the first-level gravity dust removal, the second-level spraying and the third-level activated carbon adsorption. However, the dust removal efficiency of the gravity dust collector is only between 40% and 60%, which leads to the failure of subsequent dust removal equipment. The load increases; after the industrial tail gas passes through the first stage of dust removal by the gravity dust collector, it directly enters the water shower dust collector without cooling down, which requires a large amount of spray water to fully contact the tail gas to saturate the tail gas and play the role of spraying. The load of the water spray pump will also increase accordingly; the wire mesh demister in the water spray dust collector can only partially remove the water vapor in the industrial tail gas, and the tail gas mixed with water vapor will enter the absorption tank, which will affect the adsorption effect of activated carbon. The structure of the wire mesh demister is a dense wire mesh, and the resistance under humidity conditions is between 500-1000Pa. After the system has been running for a period of time, the wire mesh demister will be blocked, resulting in an increase in the load of the induced draft fan; the activated carbon adsorption layer While adsorbing formaldehyde, it will also adsorb water vapor in industrial tail gas, so the adsorption effect is greatly reduced. At the same time, the desorption and replacement of activated carbon requires manual maintenance; industrial tail gas is directly discharged to the chimney through this process, because the tail gas is still saturated and contains a lot of water. Steam, so white fog phenomenon will be produced in winter, causing visual pollution

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