JPS58216772A - Recovering method of dust - Google Patents

Abstract

PURPOSE:To prevent the closing and trouble in the pipeline and heat exchanger in a dust recovery system in the stage of recovering the dust generated from a waste incineration installation, by forming said system in such a way that the dust consisting of low m.p. compds. can be also recovered and discharged to the outside of the system. CONSTITUTION:The waste gas 5 from a melting furnace is introduced into a heat exchanger and is cooled, whereafter the gas is introduced into a exclusive dust collector B separate from a dust collector A. After the dust contained in the gas 5 is dropped downward, the gas is supplied together with the waste gas 3 from an incineration furnace to the dust collector A where the gas is treated. The dust 8 collected in the collector B is introduced into a remelting furnace where the temp. is controlled to an adequate temp. of <=800 deg.C and after the dust is melted therein, the dust is cooled and is discharged as solidified slag 6 to the outside of the system. The dust consisting of low b.p. inorg. components such as Cl, K, Na and S components is also discharged as slag effectively to the outsid of the system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for collecting dust discharged from burning MJ equipment. This paper relates to a dust collection method.

In the equipment that incinerates and buries municipal waste, in order to solidify the incineration residue and recovered dust, a melting furnace is installed in the downstream process of the incinerator, and the incineration residual ffi recovered dust is turned into molten slag, which is then cooled. It is well known that Plan N is proposed.

FIG. 1 is a flow diagram showing a dust recovery V-stem in an incineration treatment facility for carrying out such melting treatment. That is, the waste l collected from the fabric is once stored in a storage pit and then burned in an incinerator. Incineration residues 2 such as ash and non-combustible materials and exhaust gas 8 are discharged from the incinerator, and the former is introduced into a melting furnace heated to a predetermined temperature and turned into molten slag, then cooled and solidified as solid slag 6. Expelled from the system. On the other hand, the latter exhaust gas 8 is an exhaust gas cooling bag M
When the exhaust gas is passed through a water cooling system (for example, a sprinkler type cooling system), it is cooled by K, and the dust F in the exhaust gas is removed by a dust collector A, and then discharged from the chimney. The dust 4 collected in the Bunshu dust machine is introduced into the melting furnace and is turned into molten slag together with the incineration residue 2. Furthermore, the exhaust gas generated when the incineration residue 2 and collected dust 4 are melted in the melting furnace is introduced into the bFi heat exchanger and cooled, and then sent to the dust collection HA together with the front 1a incinerator exhaust gas 8, where the dust is recycled again. It will be collected.

However, in such incineration facilities, as the equipment continues to operate for a long period of time, a considerable amount of dust adheres to the pipes and heat exchangers through which the melting furnace exhaust gas 5 flows, to the extent that there is a risk of blockages or breakdowns. Met. Therefore, in order to clarify the cause, the present inventor, Hiro, investigated the component compositions of the dust contained in the incineration residue 2, the incinerator exhaust gas 8, and the dust contained in the molten fM1 furnace exhaust gas 5. The results shown in Table 1 were obtained.

(Parts by weight) *The components of the dust collected in the flue where the exhaust gas temperature is 400-400℃, that is, the molten fM1 furnace exhaust gas dust that flows through the crystalline area where the through-circuit closure accident etc. occurred as shown in Table 1, are incineration residue and Compare with incinerator exhaust gas dust, ct.

It can be seen that the ratio of K, N & 1S components, etc. (hereinafter referred to as C/component base) is extremely high. This is contained in the incineration residue 2 and recovered dust 4, and the melting point of the 9C/component is low, and it decomposes and boils in the high temperature atmosphere of the melting furnace (1850 "CI!f@), and becomes f# melting furnace exhaust gas. This is thought to be because they were discharged together and cooled in a heat exchanger etc. before reaching the dust collector, becoming solid and becoming part of the dust. Also, these C/component fats were captured by dust collector A and dissolved in IMj. The melting furnace is re-injected into the furnace, but since the melting furnace is operated at considerably high humidity, it decomposes or boils again and is discharged as exhaust gas 6 again, reaching the dust collector A.As a result, low-boiling point inorganic components exit the system. The dust is not discharged and circulates through the dust collection V-stem.

Therefore, since the incinerator exhaust gas 8 is constantly introduced into the dust collector A, the C/component alcohol continues to accumulate in the recovery V stem, and the proportion of C/component etc. in the melting furnace exhaust gas increases. To increase. For these reasons, dust builds up on pipes and heat exchangers through which melting furnace exhaust gas flows, or the load on the dust collector AIC increases.

The present invention has been made with attention to these circumstances, and the present invention can be made without making any major changes to the existing incineration equipment line.
The purpose of this is to provide a dust collection method that can effectively discharge circulating dust from CjfillE fractionation to the outside of the thread.

Therefore, the dust collection method of the present invention includes collecting the dust in the incinerator exhaust gas with a dust collector, guiding it to the melting furnace, reducing the volume together with the incinerated ash, and providing a dust collector exclusively for the melting furnace exhaust gas.
The gist lies in reducing the volume of the bath θ by heating the dust collected by the dedicated dust collector to a pre-bath-tower-lowering temperature range.

In order to solve the above-mentioned Kan-etsu point, the inventor Hiro first focused on the physical characteristics of low-melting point dust and conducted research.

That is, the melting point and boiling point of each shelf label compound constituting the circulating dust are as shown in Table 2.

That is, the above compound is 5j02, which is the main component of incineration residue 2.
(i point: 1610℃ or higher) and A/203 (melting point: 201
The melting point and boiling point are much lower than those of 5°C), and most of them melt or decompose below 800°C and boil above 900°C. Therefore, if these compounds are heated at a suitable temperature υ higher than the melting point and lower than the line point, they can be melted without evaporating (melting), and by cooling and solidifying the obtained l?# melt or mf# compound, it becomes slag. The present invention was completed as a result of intensive research based on the above knowledge.] The present invention will be explained below with reference to the drawings of the embodiment. This invention is not intended to limit the scope of the present invention, and all modifications to the design of the present invention in accordance with the spirit described above and below are within the technical scope of the present invention.

Figure 2 is a flow diagram showing an example dust recovery system to which the method of the present invention is applied.The incinerator line etc. in the system are the same as before, but the exhaust gas 5 from the melting furnace is introduced into a heat exchanger and cooled. After that, it is introduced into a dedicated dust collector B, which is different from the dust collector A, to drop the dust contained in the exhaust gas 5, and then sent to the dust collector A together with the incinerator exhaust gas 8, where it is processed. The dust 8 collected by the dust collector B is introduced into a re-melting furnace whose temperature is adjusted to a suitable temperature of 800°C or less (preferably 550 to 600°C), where it melts into molten slag, and then cooled to form solidified slag 6. is discharged from the system as Although the above knitting degree is lower than the melting point of the ethylides shown in Table 2,
Since the mixture lowers the melting point of the chloride, it can be sufficiently melted at the above temperature. Nao again mm! The temperature of the furnace is raised using recovered heat H from the heat exchanger and an auxiliary combustion burner, but the heat source is not limited to these. For example, a heat exchanger may be placed in the flue between the incinerator and the exhaust gas cooling device. The amount of heat recovered by this K may be utilized.

The present invention is roughly configured as described above, and when collecting dust generated from waste incineration equipment, it is possible to collect dust made of low melting point compounds and discharge it to the outside of the thread. Blockage and breakdown of pipes and heat exchangers could be prevented.

[Brief explanation of the drawing]

FIG. 1 is a flowchart illustrating a conventional exhaust gas dust recovery method, and FIG. 2 is a flowchart illustrating a dust recovery method according to the present invention. 1...City! Waste 2...Incineration residue 8...Incinerator exhaust gas 4...Collected dust [dust collected by A 6...Melting furnace exhaust gas 6...Solidified slag 8...
Dust collected by Dust Collection 411B Applicant: Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] ) Collect the dust in the incinerator exhaust gas with a dust collector and melt it.
41 in the M furnace! , in a method for reducing the volume together with incineration residue and recovering dust in the blast furnace exhaust gas, a collection exclusively for melting furnace exhaust gas llA41! A method for collecting dust, characterized in that the dust F collected by 1Ω in the dedicated dust collector is heated to a temperature lower than that in the 18 melting furnace to melt and reduce the volume.