CN204202409U - A kind of cooperation-removal dust is Ji the equipment of bioxin - Google Patents

Abstract

The utility model provides a device for synergistically removing dust and dioxin, which belongs to the technical field of flue gas purification. The equipment includes 3 channels, 2 dust collectors, 2 induced draft fans and 2 chimneys; among them, channel Ⅰ is connected to the electrode hole on the airtight cover of the kennel of the electric furnace, and is used to process the four-hole exhaust gas; channel Ⅱ is connected to the electric furnace The through-hole connection of the kennel airtight cover is used to process the flue gas of the kennel; the channel III is connected to the roof cover of the electric furnace kennel airtight cover, and is used to process the smoke of the roof cover; the end of the channel I is connected to the channel II, and then connected to the dust removal in turn Device I, induced draft fan I and chimney I; the channel III is connected to dust collector II, induced draft fan II and chimney II. After the utility model synergistically purifies the dioxin and particulate matter in the flue gas of the electric furnace, the dioxin concentration and particulate matter dust concentration are guaranteed to meet the national environmental protection standard; and the structure is simple, the operation is stable and reliable, the investment is small, and the operation and maintenance cost Low.

Description

A device for synergistically removing dust and dioxin

technical field

The utility model relates to the technical field of flue gas purification, in particular to a device for synergistically removing dust and dioxin.

Background technique

Dioxin is the most poisonous substance in the world, and its toxicity is 1000 times that of potassium cyanide. The survey shows that the annual emission of various dioxins in my country is about 10.2kg-TEQ, of which the emission from iron and steel smelting is 4.59kg-TEQ, accounting for 45% of the total, and the emission from the electric furnace process in the iron and steel industry is close to 50%.

my country has promulgated the "Steel Electric Furnace, Pellet Industry Air Pollutant Emission Standard" (GB28662-2012), which has clear requirements for the emission of dioxins and particulate matter, but there is no mature and reliable dioxin purification technology in electric furnaces The machine is used in industrial applications, and there is a long way to go to meet the emission standards of dioxin emissions from electric furnaces.

The current purification of particulate matter in electric furnaces is mainly based on the filter dust removal process, which can efficiently remove dust particles in the flue gas, but there is no effective and simultaneous treatment of particulate matter and dioxins in the flue gas.

Explain the characteristics of the dust-removing flue gas in electric furnace smelting: there are three types of dust-removing flue gas during the smelting process, four-hole fume exhaust, doghouse dust-removing flue gas, and roof hood dust-removing flue gas. Among them, the flue gas from the four-hole exhaust includes the flue gas from the scrap steel preheating and the fourth hole of the electrode; the flue gas from the kennel dust removal is the flue gas in the airtight hood during the smelting process; the dust removal during the non-smelting period belongs to the roof hood dust removal.

The study found that the formation mechanism of dioxins in the electric furnace smelting process: in the early stage of melting/scrap steel preheating, organic matter such as oil, paint and coatings reacts with heat to form "precursors", which are then formed through organic compound reactions; dioxins are completely decomposed in the high temperature section , but in the cooling process, it will be synthesized again from scratch.

Combined with the generation mechanism of electric furnace smelting flue gas and dioxin, it is found that the flue gas of doghouse and four-hole flue gas contains dioxin, and the flue gas of roof hood does not contain dioxin. Moreover, scholars have found that controlling the cooling process of the flue gas from the four-hole exhaust can reduce the dioxin content in the four-hole exhaust.

At present, the removal technology of electric furnace dioxin is mainly rapid cooling, such as "Devices and methods for reducing dioxin emission in electric furnace steelmaking", which rapidly cools the high-temperature flue gas within 1-3 seconds, and controls the de novo synthesis of dioxin. The disadvantages of the rapid cooling method are: the equipment cost is high, and the amount of flue gas is increased after spraying water. At the same time, the flue gas has a high water content, and it is easy to condense on the surface of the bag filter. Moreover, the rapid cooling method can only remove dioxins in the flue gas of the four-hole flue gas exhaust, and is not suitable for the dust removal flue gas of the kennel.

Therefore, it is necessary to study a new process to simultaneously remove the dioxins in the four-hole exhaust gas, the doghouse dust removal flue gas, and the dust particles in the four-hole exhaust gas, doghouse, and roof cover flue gas.

Contents of the invention

In view of this, the purpose of this utility model is to provide a device for synergistically removing dust and dioxins, which has the advantages of simple structure, safe and stable operation, high dust removal efficiency, and no secondary pollution.

A device for synergistic removal of dust and dioxins, including 3 channels, 2 dust collectors, 2 induced draft fans and 2 chimneys; among them, channel I is connected to the electrode hole on the airtight cover of the electric furnace kennel for processing Four-hole smoke exhaust; channel Ⅱ is connected with the through hole of the airtight cover of the electric furnace kennel, used to process the smoke of the kennel; channel Ⅲ is connected with the roof cover of the airtight cover of the electric furnace kennel, used to process the smoke of the roof cover;

The channel I is sequentially provided with a water-cooled flue, a combustion settling chamber, a waste heat boiler/mechanical air cooler; the end of the channel I is connected to the channel II, and then connected to the dust collector I, the induced draft fan I and the chimney I in sequence; the channel I Ⅲ is then connected to dust collector Ⅱ, induced draft fan Ⅱ and chimney Ⅱ.

Further, the dust collector I is a catalytic filter dust collector, and the dust collector II is a filter dust collector, and the two dust collectors are independently controlled by their own automatic control systems.

Further, the catalytic filter type dust collector includes a filter bag, and the filter bag includes a filter film on the surface and a fiber material inside.

Further, the filter membrane has micropores, and the average particle diameter of the micropores is 0.8-1.2 μm.

Further, the fiber material is made of polytetrafluoroethylene or glass fiber, and catalyst powder is mixed in the fiber material.

Further, the catalyst powder contains one or several elements of V, Ti, W, Mo, and after being mixed in a certain proportion, it adheres to the surface of the fiber material, or is blocked in the pores of the fiber material, or is loaded on the surface of the fiber material in the form of a salt solution. in fiber material.

The beneficial effects of the utility model are:

1) After the utility model is used for synergistic purification of dioxins and particulates in the flue gas of the electric furnace, the concentration of dioxins in the exhausted flue gas after purification is guaranteed to be 0-0.5ng-TEQ/Nm ³ , and the dust concentration of particulates is ≤20mg/Nm 3 . Nm ³ , up to the national environmental protection standard;

2) Thoroughly catalyze and decompose the dioxin produced by electric furnace smelting, without secondary pollution;

3) For existing projects, there is no need to improve the existing dust removal process, just replace the filter bag directly, which is simple and fast, and the one-time investment is reduced;

4) According to the different content of dioxins, the flue gas from the roof cover, the flue gas from the dust removal from the kennel, and the flue gas from the four-hole fume exhaust are treated separately, and the 2 Evils, reducing the one-time investment and maintenance costs;

5) The dust-free gas after preliminary purification reacts at the catalyst, the catalyst is not easy to be poisoned, and the reactivity is improved;

6) The utility model has the advantages of simple structure, stable and reliable operation, small investment and low operation and maintenance costs.

Other advantages, objectives and features of the present utility model will be set forth in the following specification to some extent, and to some extent, will be obvious to those skilled in the art based on the investigation and research below, or can be Get teaching from the practice of the utility model. The objectives and other advantages of the utility model can be realized and obtained by the structure particularly pointed out in the following description, claims and accompanying drawings.

Description of drawings

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings, wherein:

Fig. 1 is a schematic diagram of the equipment structure of a kind of collaborative dust and dioxin removal of the utility model;

Fig. 2 is the effect schematic diagram of the catalytic filter type dust catcher of the present utility model;

In the figure: 1-electric furnace kennel airtight cover; 1.1-electric furnace body; 1.2-electrode; 1.3-roof cover; 2-channel Ⅰ; 3-channel Ⅱ; 4-channel Ⅲ; Settling chamber; 7- Jili air cooler/waste heat boiler; 8- dust collector Ⅰ; 9- induced draft fan Ⅰ; 10- chimney Ⅰ; 11- dust collector Ⅱ; 12- induced draft fan Ⅱ; 13- chimney Ⅱ; English; 14.2-dust particles; 15-gas flow direction; 16-clean gas; 17.1-filter membrane; 17.2-fiber material.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Example 1

Fig. 1 is a schematic diagram of the equipment structure of a kind of collaborative dust and dioxin removal of the utility model, as shown in the figure, a 50t electric furnace comprises the electric furnace kennel airtight cover 1 and the electric furnace furnace body 1.1, and the electric furnace furnace body 1.1 is provided with four The root electrode 1.2 is used to discharge and smelt scrap steel through electrode 1.2, and the four-hole smoke exhaust gas is discharged from the electrode holes of the fourth electrode ^. The concentration of dioxin is 2-10ng-TEQ/m ³ , and the gas velocity is about 1.5m/s.

During the smelting process, kennel flue gas will be produced at the same time, the initial temperature is about 80°C, and the dioxin concentration in it is 2-10ng-TEQ/m ³ ; during the non-smelting period, a roof cover will be generated in the kennel enclosure 1 of the electric furnace Flue gas 4, the temperature is about 30°C-40°C, and the flue gas does not contain dioxins.

This equipment includes 3 channels, 2 dust collectors, 2 induced draft fans and 2 chimneys; among them, channel Ⅰ2 is connected with the electrode hole on the airtight cover of the electric furnace kennel, and is used to process the four-hole exhaust gas; channel Ⅱ3 is connected with the electric furnace The kennel airtight cover 1.1 is connected to deal with the kennel flue gas; channel Ⅲ 4 is connected to the roof cover 1.3 of the electric furnace kennel airtight cover to process the roof hood flue gas;

The channel I is sequentially provided with a water-cooled flue 5, a combustion settling chamber 6, and a waste heat boiler/mechanical air cooler 7; the end of the channel I2 is connected to the channel II3, and then successively connected to the dust collector I8, the induced draft fan I9 and the chimney I10; The channel III4 is connected to the dust collector II11, the induced draft fan II12, and the chimney II13.

Fig. 2 is the schematic diagram of the effect of the catalytic filter type dust collector of the present utility model, as shown in Fig. 2, described dust collector I is a catalytic filter type dust collector, and dust collector II is a filter type dust collector, and 2 dust collectors are composed of respective The automatic control system is controlled separately. The catalytic filter type dust collector includes a filter bag, and the filter bag includes a filter film 17.1 on the surface and a fiber material 17.2 inside. And there are micropores on the filter membrane 17.1, and the average particle size of the micropores is 0.8-1.2 μm. The fiber material 17.2 is made of polytetrafluoroethylene or glass fiber, and catalyst powder is mixed in the fiber material 17.2; the catalyst powder contains one or more elements of V, Ti, W, Mo, and sticks after mixing in a certain proportion. Attached to the surface of the fiber material, or blocked in the pores of the fiber material, or loaded into the fiber material in the form of a salt solution, and other processes that mix the catalyst powder in the fiber material.

Example 2

Referring to Figure 1, under the action of the induced draft fan I9, the flue gas from the four-hole exhaust and the flue gas from the kennel respectively pass through the channel I2 and the channel II3 to cool down, and then lead into the dust collector I8; the channel I2 is sequentially equipped with a water-cooled flue 5. Combustion settling chamber 6. Waste heat boiler/mechanical air cooler 7; at dust collector Ⅰ8, the particulate dust in the four-hole smoke exhaust gas and doghouse flue gas is filtered on the surface of the filter bag of dust collector Ⅰ8 to realize smoke Purification of dust in the air; the purified flue gas passes through the catalyst powder contained in the fiber material inside the filter bag to realize the catalytic decomposition of dioxins in the four-hole smoke exhaust gas and doghouse flue gas, and is finally discharged through the chimney I2; the roof Under the action of the induced draft fan II12, the smoke from the hood enters the dust collector II11 through the channel III4, and after the dust particles are purified, it is discharged into the atmosphere from the chimney II13; It is discharged from the outlet of the clean air chamber of dust collector Ⅰ8 and dust collector Ⅱ11.

In this embodiment, the initial temperature of the four-hole flue gas is 1200°C-1400°C, and after passing through the combustion settling chamber, the temperature of the flue gas is 800°C-1200°C. The temperature of the flue gas is 500°C to 700°C, and after cooling down with the flue gas from the kennel, the temperature of the flue gas is 250°C to 350°C.

Referring to Fig. 2, the dust-laden flue gas flows from left to right, the flue gas contains dioxin 14.1 and dust particles 14.2, the dust particles 14.2 are intercepted when passing through the filter membrane 17.1, and the dioxin 14.1 passes through the filter The film 17.1 is completely disintegrated at the fibrous material 17.2. Finally, the clean flue gas 16 passes through the filter bag and exits the catalytic filter dust collector. Through this purification method, it is ensured that the dioxin concentration in the exhausted flue gas after purification is 0-0.5ng-TEQ/Nm ³ , and the particulate matter concentration is ≤20mg/Nm ³ .

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present utility model without limitation. Although the utility model has been described with reference to the preferred embodiment of the utility model, those of ordinary skill in the art should understand that, Various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (4)

1. A device for synergistically removing dust and dioxin, characterized in that it includes 3 channels, 2 dust collectors, 2 induced draft fans and 2 chimneys; wherein channel I is connected to the electrode on the airtight cover of the electric furnace kennel The hole connection is used to deal with the flue gas of the four-hole exhaust; the channel Ⅱ is connected with the through hole of the airtight cover of the electric furnace kennel, which is used to process the flue gas of the kennel; the channel Ⅲ is connected with the roof cover of the airtight cover of the electric furnace kennel, and is used for processing roof cover smoke; The channel I is sequentially provided with a water-cooled flue, a combustion settling chamber, a waste heat boiler/mechanical air cooler; the end of the channel I is connected to the channel II, and then connected to the dust collector I, the induced draft fan I and the chimney I in sequence; the channel I Ⅲ is then connected to dust collector Ⅱ, induced draft fan Ⅱ and chimney Ⅱ. 2. A device for collaborative dust and dioxin removal according to claim 1, characterized in that: said dust collector I is a catalytic filter dust collector, dust collector II is a filter dust collector, and two The dust collectors are individually controlled by their respective automatic control systems. 3. A kind of equipment for synergistically removing dust and dioxin according to claim 2, characterized in that: the catalytic filter type dust collector includes a filter bag, and the filter bag includes a filter film on the surface and a fiber inside Material. 4. The equipment for synergistic removal of dust and dioxins according to claim 3, characterized in that: the filter membrane has micropores, and the average particle size of the micropores is 0.8-1.2 μm.