CN209802111U - Direct evaporative cooling device for treating dioxin in electric furnace - Google Patents

Abstract

The utility model discloses a direct evaporative cooling device for controlling dioxin in an electric furnace, which belongs to the technical field of dust removal in the metallurgical industry, and comprises an adiabatic flue, an evaporative cooler, and ash transportation and storage facilities sequentially arranged outside the scrap steel preheating device of the electric furnace. There are at least two waste gas burners distributed along the axial direction of the adiabatic flue at the inlet of the adiabatic flue, several dual-medium spray guns are distributed at the outlet of the adiabatic flue along the circumference of the adiabatic flue, and the evaporative cooler is equipped with The flue gas outlet of the dust removal system pipe connection. The adiabatic flue of the utility model is also used as a flue gas channel and a combustion chamber, and the evaporative cooler is also used as a quenching tower and a settling chamber. The structure is simple, the quenching effect is good, and the automatic cleaning, transportation and centralized storage of dust can be realized.

Description

A direct evaporative cooling device for treating dioxin in electric furnace

technical field

The utility model belongs to the technical field of dust removal in the metallurgical industry, in particular to a direct evaporative cooling device for treating dioxin in an electric furnace.

Background technique

When the primary flue gas produced by the electric furnace passes through the scrap steel preheating device, it will react with the paint and other waste materials on the scrap steel surface to generate highly toxic dioxins. Therefore, the steel industry has clear requirements for dioxin emissions. However, dioxin treatment usually adopts a combination of a combustion settling chamber and a quenching tower. There are various implementations of the quenching link, such as the partition wall heat exchange described in CN201410551669 and CN201711486270, and the regenerative rapid cooling described in CN201110165286. Alkali spray quenching as described in CN201710740785. However, the structure of the above quenching device is relatively complicated, and the upstream of the quenching device is provided with a combustion and settling chamber.

Utility model content

In view of the problems existing in the device for controlling dioxins in the above-mentioned "combustion settling chamber plus rapid cooling tower", and overcoming the defects of the prior art, a device for using direct evaporative cooling technology to control dioxins in electric furnaces is provided to reduce dioxins. The oxins are generated from the source, which simplifies the structure, reduces energy consumption, and facilitates dust removal.

The utility model is achieved through the following technical solutions:

The utility model provides a direct evaporative cooling device for treating dioxin in an electric furnace, which includes an adiabatic flue, an evaporative cooler, and ash transportation and storage facilities arranged in sequence outside the scrap steel preheating device of the electric furnace. There are at least two waste gas burners distributed in the axial direction of the flue, several dual-medium spray guns are distributed at the outlet of the adiabatic flue and along the circumference of the adiabatic flue, and the evaporative cooler is provided with a flue gas outlet connected to the dust removal system pipe .

Further, it also includes an expansion joint installed between the adiabatic flue and the evaporative cooler, the expansion joint is an annular cavity structure made of heat-resistant stainless steel, the cavity is filled with fiber cotton, and is connected with the outlet of the adiabatic flue and the The inlets of the evaporative coolers are flanged.

Further, the heat-insulating flue is a steel flue gas channel with a refractory lining, and the refractory lining can adopt a combined structure of refractory bricks, heat-insulating bricks, and fiber blankets, or can use refractory castables and water-cooled pipes. combined structure.

Further, the medium of the exhaust gas burner adopts one or more combinations of natural gas, combustion-supporting air, and combustion-supporting oxygen; the dual-media spray gun is a double-layer stainless steel structure, the central pipe is passed through water, and the outer layer is passed through compressed air or nitrogen.

Furthermore, the waste gas burner can also be installed on the upstream equipment of the adiabatic flue, and the upstream equipment of the adiabatic flue is a scrap steel preheating device.

Further, the evaporative cooler is composed of a straight section of the cylinder, a lower cone section of the cylinder arranged below the straight section of the cylinder, a fixed support for installing the straight section of the cylinder, and an inspection hole for maintenance. The straight section of the body is a vertical cylinder or square structure welded by steel plates.

Further, the ash transportation and storage facility is composed of ash cleaning device, scraper ash conveyor, bucket elevator, and ash storage bin connected in sequence, and the ash cleaning device is connected to the lower cone section of the cylinder.

Further, the lower cone section of the cylinder can also be used as an ash storage bin.

Further, the average flow velocity of the flue gas in the cooler is 3-4m/s, so that the flue gas at 800-900°C is cooled to 200-250°C within 2-3s, and quickly surpasses the 300-500°C for dioxin synthesis temperature range.

Further, it also includes detection instrument and temperature control system.

The utility model has the advantages of:

1. The waste gas burner is installed on the adiabatic flue of this utility model, which is also used as a flue gas channel and a combustion chamber. There is no need to set up a separate combustion and settling chamber. The rapid cooling link uses direct evaporative cooling technology, and the evaporative cooler also serves as a rapid cooling tower and a settling chamber. Use, simple structure, good quenching effect.

2. The utility model can realize the automatic cleaning, transportation and centralized storage of dust, without using the shutdown period for dust removal.

3. The utility model can reduce the generation of dioxins from the source, and control the emission of dioxins to ≤0.1ng-TEQ/Nm3.

Other advantages, objectives and features of the present utility model will be set forth in the following description to some extent, and to some extent, based on the investigation and research below, it will be obvious to those skilled in the art, 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 through the following description.

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 structural diagram of the first embodiment of the device of the present invention, the flue gas enters the evaporative cooler from the top downward;

Fig. 2 is a structural schematic diagram of the second embodiment of the device of the present invention, the flue gas enters the evaporative cooler from the horizontal radial direction, and the lower cone section of the cylinder is also used as an ash storage bin;

Marking instructions: 1-Adiabatic flue, 2-Exhaust gas burner, 3-Double medium spray gun, 4-Expansion joint, 5-Evaporative cooler, 51-Cylinder straight section, 52-Cylinder lower cone section, 53-Fixed Support, 54-inspection hole, 6-ash transportation and storage facility, 61-ash removal device, 62-scraper ash conveyor, 63-bucket elevator, 64-ash storage bin.

Detailed ways

The implementation of the present utility model is described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The utility model can also be implemented or applied through other different specific implementation modes, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the utility model. It should be noted that the illustrations provided in the following embodiments are only schematically illustrating the basic idea of the present utility model, and the following embodiments and the features in the embodiments can be combined with each other in the case of no conflict.

Example 1:

As shown in Figure 1, the utility model provides a device for controlling dioxin in an electric furnace using direct evaporative cooling technology, including an adiabatic flue 1, an exhaust gas burner 2, a dual-medium spray gun 3, an expansion joint 4, an evaporative cooler 5 and Ash transportation and storage facilities 6, the adiabatic flue 1 is a steel flue gas channel with a refractory lining, connected to the scrap steel preheating device of the electric furnace and the evaporative cooler 5, and the exhaust gas burner 2 is installed in the adiabatic flue 1 In terms of medium, one or more combinations of natural gas, combustion-supporting air and combustion-supporting oxygen are used to ignite the combustible gas in the flue gas, mainly CO, which plays a heating role when the temperature of the flue gas is low. The number of exhaust gas burners and Medium consumption is calculated and determined according to flue gas parameters. The double-medium spray gun 3 has a double-layer structure, the central pipe is passed through water, and the outer layer is passed through compressed air or nitrogen. The water is atomized with compressed air or nitrogen. The double-medium spray gun 3 is installed in On the adiabatic flue 1 upstream of the evaporative cooler, several branches are distributed along the circumferential direction, so that the water mist covers the entire cylinder section. The expansion joint 4 is installed between the adiabatic flue and the evaporative cooler to compensate for the adiabatic flue. 1 and the thermal displacement between the evaporative cooler 5, the evaporative cooler 5 includes a straight section 51 of the cylinder, which is a vertical cylinder or a square structure welded by steel plates, and the sprayed water mist and high-temperature flue gas are in the cylinder The heat and mass exchange is carried out, all the water mist evaporates, and the high-temperature flue gas cools down rapidly. The ash storage facility 6 includes an ash cleaning device 61 , a scraper ash conveyor 62 , a bucket elevator 63 and an ash storage bin 64 .

In this embodiment, the electric furnace primary flue gas from the scrap steel preheating device passes through the adiabatic flue 1, and the CO and other waste gases in the flue gas are ignited by the waste gas burner in the adiabatic flue, and then enter the evaporative cooler 5, and the dual-medium spray gun 3. Spray water mist onto the high-temperature flue gas to play the role of fire extinguishing, cooling and coarse dust removal. The flue gas at 800-900°C cools down to 200-250°C within 2-3 seconds, and quickly crosses the temperature range of dioxin synthesis (i.e. 300 ~ 500 ℃), discharged from the lower part of the cylinder and then enter the dust removal system pipeline to achieve the purpose of reducing the generation of dioxins from the source, and control the emission of dioxins to ≤0.1ng-TEQ/Nm3.

In this embodiment, the water mist evaporates completely in a very short time, the flue gas does not condense, is unsaturated, and does not wet the wall, and the coarse dust in the evaporative cooler 5 is dry ash, which falls to the scraper ash conveyor 62, It is sent to the ash storage bin 64 through the bucket elevator 63 for centralized storage, and is regularly sent out and processed.

In this embodiment, the adiabatic flue 1 maintains a slope of not less than 0.05, and slopes toward the evaporative cooler 5 to guide the residue in the adiabatic flue to the evaporative cooler to reduce ash accumulation in the adiabatic flue.

In this embodiment, the expansion joint 4 is an annular cavity structure made of heat-resistant stainless steel, and the cavity is filled with fiber cotton, and is flanged to the outlet of the adiabatic flue 1 and the inlet of the evaporative cooler 5, which is convenient for disassembly and maintenance .

In this embodiment, the flue gas enters the evaporative cooler 5 from the top downwards. When limited by the installation height, the lower cone section 52 of the evaporative cooler can be set in the pit, and the coarse dust is sent out through the ash storage facility 6 and collected. Centralized storage.

In this embodiment, the evaporative cooler 5 is provided with a fixed support 53, and the cylinder load is transferred to the steel structure frame through the fixed support. The evaporative cooler 5 is provided with an inspection hole 54, so that it can be opened when debugging or maintenance is required. .

In this embodiment, the lower cone section 52 of the evaporative cooler is provided with a cleaning device 61, which can be cleaned by vibrating or gas to avoid hardening of coarse dust on the inner wall.

In this embodiment, it also includes a detection instrument and a temperature control system (not shown), according to the electric furnace smelting conditions, the primary flue gas flow rate and the temperature of each detection point, the number of opening and closing of the waste gas burner 2 and the number of dual-medium spray guns 3 are controlled. Water flow, the inlet/outlet temperature of the evaporative cooler 5 is controlled within a reasonable range.

Example 2:

As shown in Figure 2, as a simplified solution of Embodiment 1, the difference between this embodiment and Embodiment 1 is that the flue gas enters the evaporative cooler 5 from the horizontal radial direction, the overall installation height is reduced, and the lower cylinder of the evaporative cooler The cone section 52 is also used as an ash storage bin, and the outlet at the bottom is connected with a plate valve, a star-shaped ash unloading valve and an ash unloading pipe in sequence.

Example 3:

As a simplified solution of Embodiment 1 or Embodiment 2, the difference between this embodiment and Embodiment 1 or 2 is that the waste gas burner is installed inside the scrap steel preheating device of the electric furnace, and can be installed instead of the waste gas burner On the adiabatic flue, or the waste gas burner is on the electric furnace scrap preheating device and the adiabatic flue at the same time. The exhaust gas burner plays a beneficial role in preheating scrap steel during the process of burning exhaust gas or heating flue gas, which can reduce the power consumption of the electric furnace smelting process. Relatively speaking, installing the waste gas burner on the scrap steel preheating device has stricter requirements on its internal refractory and heat insulation. Due to the influence of the scrap steel feeding process, the inlet temperature of the evaporative cooler fluctuates greatly.

The above are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and equivalent technologies thereof, the utility model is also intended to include these modifications and variations.

Claims (10)

1. The utility model provides a administer direct evaporative cooling device of electric stove dioxin, its characterized in that includes adiabatic flue (1), evaporative cooler (5) and defeated grey facility (6) of storing up that set gradually outside electric stove scrap steel preheating device, has two at least waste gas nozzles (2) in adiabatic flue import and along adiabatic flue axial distribution, has a plurality of two medium spray guns (3) in adiabatic flue export and along adiabatic flue circumference distribution, be equipped with the exhanst gas outlet with dust pelletizing system pipe connection on the evaporative cooler.

2. the direct evaporative cooling device for treating dioxin in electric furnaces according to claim 1, further comprising an expansion joint (4) installed between the heat-insulating flue and the evaporative cooler, wherein the expansion joint is an annular cavity structure made of heat-resistant stainless steel material, the cavity of the expansion joint is filled with fiber cotton, and the expansion joint is connected with the outlet of the heat-insulating flue and the inlet of the evaporative cooler by flanges.

3. The direct evaporative cooling device for treating dioxin in electric furnaces according to claim 1, wherein the heat-insulating flue is a steel flue gas channel with a refractory lining, and the refractory lining can adopt a combined structure of refractory bricks, heat-insulating bricks and fiber blankets and can also adopt a combined structure of refractory castable and water-cooling pipes.

4. The direct evaporative cooling device for treating dioxin in electric furnaces according to claim 1, wherein the medium of the waste gas burner adopts one or a combination of a plurality of natural gas, combustion air and combustion oxygen; the double-medium spray gun is of a double-layer stainless steel structure, water is introduced into the central pipeline, and compressed air or nitrogen is introduced into the outer layer.

5. The direct evaporative cooling apparatus for treating dioxin in electric furnaces according to claim 1, wherein the exhaust gas burner is further installed in an upstream facility of the heat-insulating flue, and the upstream facility of the heat-insulating flue is an electric furnace scrap preheating device.

6. The direct evaporative cooling device for treating dioxin in electric furnaces according to claim 1, wherein the evaporative cooler is composed of a cylinder straight section (51), a cylinder lower conical section (52) arranged below the cylinder straight section, a fixed support (53) for mounting the cylinder straight section, and an inspection hole (54) for inspection, wherein the cylinder straight section is of a vertical cylinder or square structure welded by steel plates.

7. The direct evaporative cooling device for treating dioxin in electric furnaces according to claim 6, wherein the ash conveying and storing facility consists of an ash cleaning device (61), a scraper ash conveyor (62), a bucket elevator (63) and an ash storing bin (64) which are connected in sequence, and the ash cleaning device is connected to the lower conical section of the barrel.

8. the direct evaporative cooling apparatus for treating dioxin in electric furnaces according to claim 7, wherein the lower cone section of the barrel can be used as a dust storage bin.

9. The direct evaporative cooling device for treating dioxin in electric furnaces according to claim 1, wherein the average flow velocity of flue gas in the cooler is 3-4 m/s, the temperature of the flue gas at 800-900 ℃ is reduced to 200-250 ℃ within 2-3 s, and the flue gas rapidly crosses a temperature range of 300-500 ℃ for dioxin synthesis.

10. The direct evaporative cooling apparatus for abatement of furnace dioxins as set forth in claim 1, further comprising a meter and a temperature control system.