Fly ash smelting pre-treatment system and fly ash treating method

Abstract

The invention provides a fly ash smelting pre-treatment system which comprises a raw material storage bin, a pelleting device and a smelting furnace, wherein the rear part of the raw material storage bin is connected to the pelleting device; the rear part of the pelleting device is connected with a first hoister; the rear part of the first hoister is connected to a finished product bin; the rear part of the finished product bin is connected to a second hoister; the rear part of the second hoister is connected to the smelting furnace; the pelleting device comprises a forced feeding machine connected with the raw material storage bin; the rear part of the forced feeding machine is connected to a piece rolling main engine; the rear part of the piece rolling main engine is connected to a crushing machine; the rear part of the crushing machine is connected to a straightening granulator; the rear part of the straightening granulator is connected with a grading sieve; the grading sieve is connected with the first hoister. According to the fly ash smelting pre-treatment system provided by the invention, powdered fine fly ash are compressed to be blocky, are crushed into particles with proper size by using the crushing machine, and cannot diffuse into air during the transportation process; the particulate matters cannot drift into a tail gas treating system along with tail gas after being conveyed to the thermolysis smelting furnace; therefore, the bridging phenomenon and the phenomenon that particles are adhered to a wall are avoided.

Description

technical field [0001] The invention relates to hazardous waste treatment equipment, in particular to a pretreatment system in fly ash melting and pyrolysis technology. This pretreatment system is a device for morphological treatment of fly ash during the process of transporting fly ash from the fly ash storage area to the pyrolysis melting furnace. Background technique [0002] With the rapid development of domestic waste and medical waste incineration, the output of incineration fly ash is increasing year by year. Waste incineration fly ash contains a large amount of heavy metals, such as Hg, Cd, Pb, Cr and Zn, as well as dioxin and furan organic pollutants, etc. The following table shows the composition of a fly ash and its heavy metal content. [0003] Main components and heavy metal content of a waste incineration fly ash [0004] main ingredient Content / % heavy metal elements Content / mg.kg -1 CaO 26.842 Pb 2055 SiO 2 ...

AI Technical Summary

Problems solved by technology

[0005] The dioxins in the fly ash account for more than 60% of the total dioxins produced in the incineration process. During the treatment, due to the dusty form, it is easy to spread into the air and cause pollution to the environment. The fly ash is transported into the processing equipment It is also easy to be directly removed with the flue gas, resulting in incomplete treatment

[0006] Because the fly ash particles are very small, they are actually suspended in the channel and cannot be directly transported to the processing equipment. During the transport process, they will diffuse into the air through some small gaps between the equipment connection parts and the equipment itself, causing pollution to the environment.

Since many processing equipments are under internal negative pressure, if the fly ash is directly put into the processing equipment, the fly ash particles will be directly scattered into the exhaust gas, and then spread to the exhaust gas treatment system with the exhaust gas, resulting in adverse consequences: secondary fly ash If the output is too high, it can reach 50% of the feed amount, which will make the treatment efficiency low; it will block the rear pipeline and increase the pressure of tail gas treatment, so that the treatment work cannot be carried out continuously

In addition, the small particle size of fly ash leads to large surface area and high friction between particles. During the process of feeding fly ash into the plasma device, "bridging" and wall hanging phenomenon will be formed, resulting in the inability of continuous feeding of fly ash, and forced feeding will make The feeder is stuck

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