Lump ore drying system using waste heat of sintering denitration flue gas

Abstract

The utility model discloses a lump ore drying system utilizing waste heat of sintering and denitration flue gas, relates to the technical field of utilization of waste heat of sintering and denitration flue gas, and aims to solve the problem that utilization ways of waste heat of sintering and denitration flue gas need to be increased and improved. The waste heat drying system is provided with an air taking unit, a drying unit, a screening unit and an air returning unit, the air taking unit is arranged between a flue gas denitration device and a pressurizing induced draft fan and is composed of a hot air pipeline, a connector flange and a compensator, and the hot air pipeline is wrapped by a heat preservation layer; outlet air of the air taking unit and discharged materials of the lump ore transfer device are introduced into the drying unit, lump ore discharged materials are connected to the screening unit, a cold smoke air outlet of the drying unit is connected with an inlet of the air return unit, and an outlet of the air return unit is communicated to an air inlet of the pressurization induced draft fan. The device can dry lump ores by using waste heat of sintering denitration flue gas, is beneficial to enhancing the production stability of the blast furnace and reducing the smelting energy consumption, and is low in investment, quick in effect, simple and easy to implement.

Description

Technical Field

[0001] The utility model relates to the technical field of utilization of waste heat from sintering and denitrification flue gas, in particular to a lump ore drying system using waste heat from sintering and denitrification flue gas. Background Art

[0002] Green and low-carbon development has become the future goal of the steel industry.

[0003] At present, the raw materials for pig iron required by the steel industry are mainly provided by blast furnace smelting; natural lump ore is one of the furnace charges, and its addition amount can be up to 30%. Most natural lump ores are imported ores; they are shipped from the sea to the raw material terminal, and then transported to the lump ore shed of the steel enterprise after temporary storage; the transportation and storage process will cause the lump ore powder content and moisture content to increase. After the lump ore enters the furnace, the water gasification requires energy consumption. The high powder rate reduces the permeability of the material layer and increases the coke ratio, resulting in an increase in the blast furnace smelting cost and affecting the stability of the furnace condition. Therefore, the reduction of lump ore powder and moisture content is of great significance to increase the permeability of the blast furnace material layer, enhance the stability of the furnace condition, reduce the energy consumption of blast furnace smelting, and save costs.

[0004] Sintering is an important process in the pre-iron system. It mainly uses solid fuels such as anthracite or coke powder for heating. The flue gas produced contains SO x and NO x It is also a major carbon emitter. According to national environmental protection standards and emission requirements, sintering flue gas must be purified by "desulfurization and dust removal + denitrification" before it can meet emission standards; after denitrification, the flue gas still has a certain amount of heat, about 120°C, which has considerable utilization value. At present, the main utilization of flue gas waste heat is focused on tubular heat exchange-heating water to obtain steam, and there is a lack of research and improvement in other utilization methods. In summary, a sintering denitrification flue gas waste heat block ore drying system is urgently needed to solve this problem. Utility Model Content

[0005] The utility model aims to provide a sintering denitrification flue gas waste heat lump ore drying system to solve the problem that the utilization methods of sintering denitrification flue gas waste heat need to be increased and improved.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a sintering denitrification flue gas waste heat lump ore drying system, including a lump ore dumping system and a sintering flue gas desulfurization and denitrification system. The lump ore dumping system is provided with a lump ore transfer device for transporting lump ore from the lump ore storage shed and a feeding ore trough to be fed into the blast furnace. The sintering flue gas desulfurization and denitrification system is provided with a flue gas denitrification device for denitrification and a booster induced draft fan connected to the gas outlet end thereof; it also includes a waste heat drying system, which is provided with an air intake unit, The drying unit, screening unit and return air unit, the air intake unit is arranged between the flue gas denitrification device and the booster induced draft fan, which is composed of a hot air duct, an interface flange and a compensator, and the hot air duct is wrapped with an insulation layer; the air outlet of the air intake unit and the discharge of the lump ore transfer device are respectively introduced into the drying unit, and the lump ore discharge is connected to the screening unit, which is used to send the lump ore to the loading ore trough after whole grain processing, the cold flue gas outlet of the drying unit is connected to the inlet of the return air unit, and the outlet of the return air unit is connected to the air inlet of the booster induced draft fan.

[0007] Preferably, the waste heat drying system is also provided with a drain unit, and the return air unit includes a cold flue gas duct, a connecting flange and a compensator, wherein the cold flue gas duct is provided with a horizontal section or a U-shaped pipe, one end of the drain unit is connected to the lower end of the horizontal section or the U-shaped pipe for collecting condensed water, and the other end is connected to a nearby ditch or drainage system for discharging condensed water.

[0008] Preferably, a dust collector is also included, and dust and steam outlets are respectively opened at the upper ends of the lump ore transfer device, the loading ore trough, the drying unit, and the screening unit, and are respectively connected to the dust collector through pipelines.

[0009] Preferably, the drying unit includes a drying device, the outer side of which is wrapped with insulation material, the upper end of the drying device is provided with a lump ore transfer inlet, a cold air exhaust outlet and a dust and steam exhaust outlet, the lower end is provided with a hot air inlet and a lump ore unloading outlet, the air outlet of the air intake unit is connected to the hot air inlet through a pipe and a flange; the lump ore transfer device adopts a belt conveyor, and its discharge is connected to the lump ore transfer inlet; the cold air exhaust outlet is connected to the inlet of the return air unit through a pipe and a flange; the lump ore unloading outlet is connected to the feed inlet of the screening unit.

[0010] Preferably, the sintering flue gas desulfurization and denitrification system also includes a sintering large flue, a sintering electrostatic precipitator, a sintering main exhaust fan, a flue gas desulfurization and dust removal device, and a chimney connected to the air outlet of the booster induced draft fan, wherein the air outlet of the flue gas desulfurization and dust removal device is connected to the air inlet of the flue gas denitrification device.

[0011] Preferably, the undersize powder of the screening unit is transported to the sintering batching unit for recycling.

[0012] Preferably, two non-communicating chambers are provided in the drying unit, which are separated by a heat transfer plate, the air intake unit and the return air unit are respectively connected to the two ends of one of the chambers, and the lump ore transfer device and the screening unit are respectively connected to the two ends of the other chamber.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] 1. The sintering denitrification flue gas waste heat lump ore drying system can use the waste heat of the flue gas after denitrification to pre-treat the lump ore from the lump ore terminal and stored in the material shed for a period of time. Through unit operations such as drying and screening, the moisture and dust content in the lump ore can be effectively reduced. The dust can be further removed by setting up a dust collector, which makes full use of the waste heat of the sintering denitrification flue gas, is beneficial to enhancing the stability of blast furnace production and reducing smelting energy consumption, with low investment, quick results, simple and easy operation, and no special equipment, materials and raw materials are required.

[0015] 2. In the sintering denitrification flue gas waste heat block ore drying system, compensators are installed in the pipelines to absorb the thermal expansion of the pipelines and ensure the safety of the facilities; the pipeline interfaces are connected by flanges, which are easy to ensure sealing and convenient for disassembly and maintenance; the outside of the hot air pipeline is wrapped with an insulation layer, and the outside of the drying device is wrapped with insulation materials, which can reduce heat loss and improve heat utilization efficiency.

[0016] 3. The sintering denitrification flue gas waste heat lump ore drying system adopts the method of lump ore entering from top and exiting from bottom, and hot air entering from bottom and exiting from top in the drying unit, which can realize the relative movement of lump ore and hot air, and can carry out continuous, lasting and progressive heat exchange to achieve good drying effect.

[0017] 4. The sintering denitrification flue gas waste heat lump ore drying system screens the lump ore after drying, which can not only reduce the adverse effects of powder on blast furnace production, but also realize the comprehensive utilization of mineral resources.

[0018] 5. The sintering denitrification flue gas waste heat lump ore drying system does not require the addition of other production workshops except the drying unit and screening unit. The scheme is simple and practical, the process operation is simple and reliable, and the dust and wastewater are removed and drained separately to meet environmental protection needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall system structure of the utility model;

[0020] Figure 2 This is a schematic diagram of the drying unit structure of the utility model.

[0021] In the figure: K1 - lump ore wharf, K2 - lump ore storage shed, K3 - lump ore transfer device, K4 - loading ore chute, K5 - blast furnace;

[0022] F1—sintering flue, F2—sintering electrostatic precipitator, F3—sintering main exhaust fan, F4—flue gas desulfurization and dust removal device, F5—flue gas denitrification device, F6—boosting induced draft fan, F7—chimney;

[0023] H1—air intake unit, H2—drying unit, H3—screening unit, H4—return air unit, H5—drainage unit; H201—drying device, H202—lump ore transfer entrance, H203—hot air inlet, H204—cold air outlet, H205—lump ore unloading outlet, H206—dust and steam outlet;

[0024] C1—dust collector, S1—sintering batching unit, P1—drainage system. DETAILED DESCRIPTION

[0025] like Figure 1 As shown, a sintering denitrification flue gas waste heat lump ore drying system includes a lump ore dumping system and a sintering flue gas desulfurization and denitrification system. The lump ore dumping system is provided with a lump ore transfer device K3 for transporting lump ore from a lump ore storage material shed K2 and a feeding ore trough K4 to be fed into a blast furnace K5. The sintering flue gas desulfurization and denitrification system is provided with a flue gas denitrification device F5 for denitrification and a booster induced draft fan F6 connected to its air outlet; it also includes a waste heat drying system, which is provided with an air intake unit H1, a drying unit H2, a screening unit H3 and a return air unit H4. The air intake unit H1 is arranged between the flue gas denitrification device F5 and the booster induced draft fan F6, and is composed of a hot air duct, an interface flange and a compensator. The hot air duct It is wrapped with a heat-insulating layer on the outside; the air outlet of the air intake unit H1 and the output of the lump ore transfer device K3 are respectively introduced into the drying unit H2, and the lump ore output is connected to the screening unit H3, which is used to send the lump ore to the loading ore trough K4 after granulation. The cold smoke outlet of the drying unit H2 is connected to the inlet of the return air unit H4, and the outlet of the return air unit H4 is connected to the air inlet of the booster induced draft fan F6; specifically, two non-communicating chambers are preferably provided in the drying unit H2, which are separated by a heat transfer plate, the air intake unit H1 and the return air unit H4 are respectively connected to the two ends of one of the chambers, and the lump ore transfer device K3 and the screening unit H3 are respectively connected to the two ends of the other chamber, so that the ore and air are indirectly dried separately to avoid smoke blockage.

[0026] In a preferred embodiment, the return air unit H4 includes a cold flue gas duct, a connecting flange and a compensator, wherein the cold flue gas duct is provided with a horizontal section or a U-shaped duct, and the waste heat drying system is also provided with a drain unit H5, one end of the drain unit H5 is connected to the lower end of the horizontal section or the U-shaped duct for collecting condensed water, and the other end is connected to a nearby ditch or drainage system P1 for discharging condensed water.

[0027] In order to further improve the dust removal effect of the system, the waste heat drying system can also include a dust collector C1, see Figure 1The upper ends of the lump ore transfer device K3, the loading ore trough K4, the drying unit H2, and the screening unit H3 are respectively provided with dust and steam ports, which are respectively connected to the dust collector C1 through pipelines. Usually, each dust and steam port is in a slightly negative pressure state, and is generally drained by a dust removal fan to collect and process part of the dust (steam) in each unit. If the drying unit H2 adopts the above-mentioned two-chamber structure, the chamber through which the lump ore passes is connected to the dust collector C1, and the chamber where the flue gas is located is not connected to the dust collector C1.

[0028] See also Figure 2 In a preferred embodiment, the drying unit H2 can adopt the following structure, including a drying device H201, the outer side of which is wrapped with insulation material, the upper end of the drying device H201 is provided with a lump ore transfer entrance H202, a cold air exhaust outlet H204 and a dust and steam exhaust outlet H206, and the lower end is provided with a hot air inlet H203 and a lump ore discharge outlet H205, the air outlet of the air intake unit H1 is connected to the hot air inlet H203 through a pipe and a flange; the lump ore transfer device K3 adopts a belt conveyor, and its discharge is connected to the lump ore transfer entrance H202; the cold air exhaust outlet H204 is connected to the inlet of the return air unit H4 through a pipe and a flange; the lump ore discharge outlet H205 is connected to the feed inlet of the screening unit H3.

[0029] In addition, the sintering flue gas desulfurization and denitrification system also includes a sintering large flue F1, a sintering electrostatic precipitator F2, a sintering main exhaust fan F3, a flue gas desulfurization and dust removal device F4, and a chimney F7 connected to the air outlet end of the booster induced draft fan F6. The air outlet end of the flue gas desulfurization and dust removal device F4 is connected to the air inlet end of the flue gas denitrification device F5 for denitrification.

[0030] Although the main function of the screening unit H3 is to reduce the powder entering the blast furnace, avoid high powder rate reducing the permeability of the material layer and increasing the coke ratio, which is beneficial to saving blast furnace smelting costs and maintaining furnace conditions, the under-screen powder of the screening unit H3 can also be transported to the sintering batching unit S1 for recycling.

[0031] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

[0032] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A sintering denitrification flue gas waste heat lump ore drying system, comprising a lump ore transfer system and a sintering flue gas desulfurization and denitrification system, wherein the lump ore transfer system is provided with a lump ore transfer device (K3) for transporting lump ore from a lump ore storage shed (K2) and a feeding ore trough (K4) to be fed to a blast furnace (K5), and the sintering flue gas desulfurization and denitrification system is provided with a flue gas denitrification device (F5) for denitrification and a booster induced draft fan (F6) connected to the gas outlet end thereof, characterized in that: It also includes a waste heat drying system, which is provided with an air intake unit (H1), a drying unit (H2), a screening unit (H3) and a return air unit (H4). The air intake unit (H1) is arranged between the flue gas denitrification device (F5) and the booster induced draft fan (F6), and is composed of a hot air duct, an interface flange and a compensator. The hot air duct is wrapped with an insulation layer. The air outlet of the air intake unit (H1) and the discharge of the lump ore transfer device (K3) are respectively introduced into the drying unit (H2), and the lump ore discharge is connected to the screening unit (H3) for sending the lump ore to the loading ore trough (K4) after granulation. The cold flue gas outlet of the drying unit (H2) is connected to the inlet of the return air unit (H4), and the outlet of the return air unit (H4) is connected to the air inlet of the booster induced draft fan (F6).

2. The sintering denitrification flue gas waste heat lump ore drying system according to claim 1, characterized in that: The waste heat drying system is also provided with a drain unit (H5), and the return air unit (H4) includes a cold flue gas duct, a connecting flange and a compensator, wherein the cold flue gas duct is provided with a horizontal section or a U-shaped duct, one end of the drain unit (H5) is connected to the lower end of the horizontal section or the U-shaped duct to collect condensed water, and the other end is connected to a nearby ditch or drainage system (P1) to discharge the condensed water.

3. The sintering denitrification flue gas waste heat lump ore drying system according to claim 1, characterized in that: It also includes a dust collector (C1), and the upper ends of the lump ore transfer device (K3), the loading ore trough (K4), the drying unit (H2), and the screening unit (H3) are respectively provided with dust and steam ports, which are connected to the dust collector (C1) through pipelines.

4. The sintering denitrification flue gas waste heat lump ore drying system according to claim 1, characterized in that: The drying unit (H2) comprises a drying device (H201) whose outer side is wrapped with heat-insulating material. The upper end of the drying device (H201) is provided with a lump ore transfer inlet (H202), a cold air outlet (H204) and a dust and steam outlet (H206), and the lower end is provided with a hot air inlet (H203) and a lump ore discharge outlet (H205). The air outlet of the air intake unit (H1) is connected to the hot air inlet (H203) through a pipeline and a flange; the lump ore transfer device (K3) adopts a belt conveyor, and its discharge is connected to the lump ore transfer inlet (H202); the cold air outlet (H204) is connected to the inlet of the return air unit (H4) through a pipeline and a flange; the lump ore discharge outlet (H205) is connected to the feed inlet of the screening unit (H3).

5. The sintering denitrification flue gas waste heat lump ore drying system according to claim 1, characterized in that: The sintering flue gas desulfurization and denitrification system also includes a sintering large flue (F1), a sintering electrostatic precipitator (F2), a sintering main exhaust fan (F3), a flue gas desulfurization and dust removal device (F4) which are connected in sequence according to the flue gas flow direction, and a chimney (F7) connected to the air outlet end of the booster induced draft fan (F6), wherein the air outlet end of the flue gas desulfurization and dust removal device (F4) is connected to the air inlet end of the flue gas denitrification device (F5).

6. The sintering denitrification flue gas waste heat lump ore drying system according to claim 1, characterized in that: The undersize powder from the screening unit (H3) is transported to the sintering batching unit (S1) for recycling.

7. A sintering denitrification flue gas waste heat lump ore drying system according to any one of claims 1 to 6, characterized in that: The drying unit (H2) is provided with two non-communicating chambers separated by a heat transfer plate, the air intake unit (H1) and the air return unit (H4) are respectively connected to the two ends of one of the chambers, and the lump ore transfer device (K3) and the screening unit (H3) are respectively connected to the two ends of the other chamber.

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