A ventilation system combining a spray with a mobile exhaust hood

Abstract

The present invention discloses a ventilation system combining spraying with a mobile exhaust hood, which includes a spraying system and a ventilation system. The spraying system includes a hollow cone atomizing nozzle, a water supply system, a gas supply system and a header. Among them, the water supply system and the gas supply system are connected to the header, and the header is connected to the inlet of the hollow cone atomizing nozzle. The ventilation system includes a main air duct of the finishing mill, a linkage controller, a computer control system, a number of fans and a number of exhaust systems. Each fan is connected to the main air duct of the finishing mill. Each exhaust system includes a mobile exhaust hood opening and an air duct. The mobile exhaust hood opening is connected to the main air duct of the finishing mill through the air duct. The computer control system is connected to the control ends of each fan through the linkage controller. This system has a good effect on removing pollutants from the finishing mill and has an energy-saving space.

Description

Technical Field

[0001] The present invention relates to a ventilation system, and more particularly to a ventilation system combining spraying with a movable exhaust hood. Background Art

[0002] During the rolling process, a large amount of particulate matter generated by the strip steel is the main source of particulate matter emission in the finishing mill area. During the finishing rolling process, after one section of strip steel is rolled, there is an interval for a period of time, and then the next section of strip steel is rolled, and so on continuously. Among them, the rolling time of the strip steel and the intermittent time in the finishing rolling process are basically equal. In addition, along the rolling direction, the pollutant exhaust air volume of each finishing mill increases in turn.

[0003] However, at present, the exhaust hoods of the finishing mills in the workshop are continuously operating, and the specifications of the exhaust hoods on each finishing mill in the finishing mill area are the same, and the selected exhaust air volumes are the same. Therefore, the design is not reasonable enough and there is a large energy-saving space. Therefore, the removal effect of pollutants from the finishing mills is poor, and there is also an energy-saving space. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art, and provide a ventilation system combining spraying with a movable exhaust hood, which has a good removal effect on pollutants from the finishing mills and also has an energy-saving space.

[0005] To achieve the above purpose, the ventilation system combining spraying with a movable exhaust hood described in the present invention includes a spraying system and a ventilation system. The spraying system includes a hollow conical atomizing nozzle, a water supply system, an air supply system and a header pipe. Among them, the water supply system and the air supply system are connected to the header pipe, and the header pipe is connected to the inlet of the hollow conical atomizing nozzle.

[0006] The ventilation system includes a main air duct of the finishing mill, a linkage controller, a computer control system, a number of fans and a number of exhaust systems; each fan is connected to the main air duct of the finishing mill, and each exhaust system includes a movable exhaust hood opening and an air duct. The movable exhaust hood opening is connected to the main air duct of the finishing mill through the air duct, and the computer control system is connected to the control ends of each fan through the linkage controller.

[0007] The water supply system includes a water purification device, a water pump, a water switch control valve, a water filter, a water pressure regulator and a water supply pipe. Among them, the outlet of the water purification device is connected to the header pipe through the water pump, the water switch control valve, the water filter, the water pressure regulator and the water supply pipe in sequence.

[0008] The air supply system includes an air switch control valve, an air filter, an air pressure regulator and an air supply pipe. Among them, the air switch control valve is connected to the header pipe through the air filter, the air pressure regulator and the air supply pipe in sequence.

[0009] The movable exhaust hood opening is connected to the air duct through a rotating component.

[0010] It also includes a dust removal system and a dehydrator. The outlet of the main air duct of the finishing mill is connected to the dust removal system through the dehydrator.

[0011] The present invention has the following beneficial effects:

[0012] When the ventilation system combining spraying with a mobile exhaust hood is specifically operated, atomized droplets are sprayed into the rolling area through hollow conical atomizing nozzles to suppress the emission of flue gas. Compared with full cone nozzles, the hollow conical atomizing nozzles can form fine droplets, and the nozzle spacing is 200 - 300 mm to improve the capture efficiency of water mist and dust, reduce the emitted high-temperature pollutants from the source. At the same time, the ventilation system is used to inhale the escaped dust, improve the removal effect of pollutants from the finishing mill, occupy less space. Also, during actual operation, it can be coupled with the working parameters of the finishing mill through a computer control system to control the operation of the fan and reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the present invention;

[0014] Figure 2 It is a position diagram of the mouth 2 of the mobile exhaust hood when rolling the strip steel 3;

[0015] Figure 3 It is a position diagram of the mouth 2 of the mobile exhaust hood when in a non-working state;

[0016] Figure 4 It is a position diagram of the hollow conical atomizing nozzle 1 in the present invention;

[0017] Figure 5 It is a control schematic diagram of the fan 9;

[0018] Figure 6 It is a schematic structural diagram of the spraying system;

[0019] Figure 7 It is a relationship diagram of the hollow conical atomizing nozzle 1 and the header 14;

[0020] Figure 8 It is a working schematic diagram of the mobile exhaust hood;

[0021] Figure 9 It is a control logic diagram of the fan 9;

[0022] Figure 10a It is a flue gas effect diagram without spraying water mist;

[0023] Figure 10b It is a flue gas effect diagram after spraying water mist.

[0024] Among them, 1 is a hollow conical atomizing nozzle, 2 is the mouth of a mobile exhaust hood, 3 is a strip steel, 4 is a rolling mill roll, 5 is a finishing mill, 6 is an air duct, 7 is the main air duct of a single stand finishing mill, 8 is the main air duct of the finishing mill, 9 is a fan, 10 is a linkage controller, 11 is a computer control system, 12 is a water pump, 13 is a water purification device, 14 is a header, 141 is a water supply pipe, 142 is an air supply pipe, 15 is a water switch control valve, 16 is a water filter, 17 is a water pressure regulator, 18 is an air pressure regulator, 19 is an air filter, and 20 is an air switch control valve; Detailed implementation mode

[0025] The present invention will be further described in detail below with reference to the accompanying drawings:

[0026] Refer to Figure 1 , the ventilation system combining spraying and a mobile exhaust hood of the present invention includes a spraying system and a ventilation system. The spraying system includes a hollow conical atomizing nozzle 1, a water supply system, an air supply system, and a header 14. Among them, the water supply system and the air supply system are connected to the header 14, and the header 14 is connected to the inlet of the hollow conical atomizing nozzle 1; the ventilation system includes the main air duct 8 of the finishing mill, a linkage controller 10, a computer control system 11, a plurality of fans 9, and a plurality of exhaust systems; each fan 9 is connected to the main air duct 8 of the finishing mill, and each exhaust system includes the mouth 2 of a mobile exhaust hood and an air duct 6. The mouth 2 of the mobile exhaust hood is connected to the main air duct 8 of the finishing mill through the air duct 6, and the computer control system 11 is connected to the control end of each fan by the linkage controller 10.

[0027] The water supply system includes a water purification device 13, a water pump 12, a water switch control valve 15, a water filter 16, a water pressure regulator 17, and a water supply pipe 141. Among them, the outlet of the water purification device 13 is connected to the header 14 through the water pump 12, the water switch control valve 15, the water filter 16, the water pressure regulator 17, and the water supply pipe 141 in sequence.

[0028] The air supply system includes an air switch control valve 20, an air filter 19, an air pressure regulator 18, and an air supply pipe 142. Among them, the air switch control valve 20 is connected to the header 14 through the air filter 19, the air pressure regulator 18, and the air supply pipe 142 in sequence.

[0029] For the ventilation of a single finishing mill, when rolling the strip steel 3, the mouth 2 of the mobile exhaust hood rotates to the side facing the working roll of the rolling mill roll 4 along the rolling direction, as Figure 2 shown; when in a non-working state, the mouth 2 of the mobile exhaust hood turns away and is on one side of the finishing mill, as Figure 3As shown; if the rolling mill is in the roll-changing state, the hood opening 2 of the mobile exhaust hood of this rolling mill swings towards the adjacent rolling mill side, leaving sufficient space for roll changing and not affecting the process operation. The air duct 6 has a rotating component to drive the small arm of the hood opening 2 of the mobile exhaust hood to rotate.

[0030] For the entire ventilation system of the finishing mill, when rolling the strip steel 3, all the fans 9 are controlled to start and operate by the linkage controller 10. The fans 9 are connected to the hood openings 2 of the respective mobile exhaust hoods through the air ducts 6. Each fan 9 is controlled by the linkage controller 10, and the linkage controller 10 is connected to the computer control system 11. The computer control system 11 has the process operation parameters built-in and coordinates the ventilation system with these process operation parameters.

[0031] Since the strip steel rolling in the finishing process is an intermittent operation, that is, it rolls a section of strip steel 3 and then has an intermittent period, and then rolls the next section of strip steel 3. A large amount of high-temperature pollutants are only generated during the process of rolling the strip steel 3. Therefore, the operation of the fans 9 is coordinated with the rolling process operation parameters. That is, when rolling the strip steel 3, the linkage controller 10 is started, and the fans 9 operate to capture pollutants; during the intermittent period, the fans 9 stop operating or operate at a low frequency. According to the finishing rolling cycle, the start and stop times are both about one minute and fifteen seconds, and the specific time can also be determined according to the specific process conditions. The control principle is as Figure 8 shown.

[0032] As Figure 5 shown, according to the specific relationship of the pollutants increasing in each workshop in turn, through the linkage controller 10, each fan 9 is uniformly controlled, so that each finishing mill is accurately controlled, which not only improves the capture efficiency of each finishing mill in the later stage of rolling, but also does not make the designed exhaust air volume of the finishing mill in the early stage of rolling too large, resulting in energy waste during operation.

[0033] During actual operation, hollow conical atomizing nozzles 1 are used for upper and lower spraying on one side of the roll 4 in each finishing mill, as Figure 4As shown, after the flue gas enters this area, the upper and lower rows of sprays are ejected at a speed of about 3000 m / s under pressure to inhibit the emission of flue gas. Compared with full cone nozzles, the hollow conical atomizing nozzle 1 can form fine droplets, and the nozzle spacing is 200 - 300 mm. The nozzle with an atomization particle size of 30 μm is selected in this invention to improve the capture efficiency of water mist and dust, and reduce the emitted high-temperature pollutants at the source. Due to the high spray speed, during continuous spraying, part of the spray is ejected to the front and rear sides of the finishing mill 5 due to hitting the rolling mill 4. The relatively high spray speed has an entrainment effect, and part of the flue gas will be entrained and directionally escape to the two sides of the finishing mill 5 along with it. Therefore, the mobile exhaust hood opening 2 is set at the position where the flue gas escapes. The length of the mobile exhaust hood opening 2 is 0.8 m, and the width is 0.6 m. It should not be too small. This size can ensure the complete capture of flue gas and will not be blocked by process devices such as spray pipes, making the mobile exhaust hood opening 2 ineffective.

[0034] As Figure 7 shown, the working principle of the ventilation system of this invention is as follows: Utilize the entrainment effect of the spray. The spray speed is relatively high, and the flue gas carried has a directionality and escapes to the front and rear sides of the rolling mill; utilize the dust suppression effect. Due to the principles of aerodynamics, Stefan flow transport theorem, and "cloud" physics, under the action of water mist, the soot agglomerates and settles; utilize the great potential of water to carry away a large amount of heat in a high-temperature environment, greatly reducing the flue gas temperature, reducing the flue gas buoyancy, and reducing the escape speed of the flue gas into the environment, thereby significantly reducing the flue gas emission.

[0035] The water mist dust suppression and ventilation system of this invention for the finishing mill reduces the pollutant emission as much as possible from the pollution source. In cooperation with an energy-saving ventilation system, it is beneficial to create a clean factory environment, reduce the ventilation energy consumption, and maximize energy conservation.

[0036] Simulation experiment

[0037] According to the geometric prototype of the finishing process, reasonable simplification is carried out, modeled with ICEM and meshed, and numerically calculated with FLUENT. The DPM model is used to simulate the spray. Injection selects the hollow conical nozzle. In the simulation, the Realizable k-ε model, which is the most commonly used in engineering, is selected for the turbulence model. The numerical method has been verified. CO is selected as the tracer gas for the high-temperature flue gas. The boundary conditions are set according to the on-site conditions. The spray particle size is set to 30 μm, and the injection speed is set to 3000 m / s. The flue gas effects without spraying water mist and after spraying water mist are as Figure 10a and Figure 10bAs shown, when the spray is not used, a large amount of flue gas escapes from the front and the back of the rolling mill, and the flue gas spreads all around the rolling mill; when the spray is used, it can be clearly seen that the flue gas only escapes directionally from the front of the rolling mill and the front part of the wedge-shaped body on the back of the rolling mill. In the present invention, the hood opening 2 of the mobile exhaust hood is arranged at the two sides where the flue gas escapes. According to the estimation of the area where the flue gas emerges from the source, the length of the hood opening 2 of the mobile exhaust hood required by the present invention is 0.8 m and the width is 0.6 m, which meets the requirement for capturing the flue gas. Therefore, after the hood opening 2 of the mobile exhaust hood of the present invention is used, the flue gas will not escape to the surrounding environment, thus greatly improving the working environment in the finishing mill area and being conducive to creating a clean factory environment.

Claims

1. A ventilation system combining spray and mobile exhaust hood, characterized in that: The invention comprises a spray system and a ventilation system, wherein the spray system comprises a hollow conical atomizing nozzle (1), a water supply system, an air supply system and a header (14), wherein the water supply system and the air supply system are connected to the header (14), and the header (14) is connected to the inlet of the hollow conical atomizing nozzle (1); The ventilation system comprises a main air duct (8) of the finishing mill, a linkage controller (10), a computer control system (11), a plurality of fans (9) and a plurality of exhaust systems; each fan (9) is connected to the main air duct (8) of the finishing mill, each exhaust system comprises a movable exhaust hood opening (2) and an air duct (6), the movable exhaust hood opening (2) is connected to the main air duct (8) of the finishing mill through the air duct (6), and the computer control system (11) is connected to the control end of each fan (9) through the linkage controller (10); A hollow cone atomizing nozzle (1) is used on one side of the roller (4) in each finishing mill to spray upward and downward. The upper and lower rows of spray are sprayed at a speed of 3000 m / s under pressure. The atomized particle size of the hollow cone atomizing nozzle (1) is 30 μm. The movable exhaust hood opening (2) is set at the smoke escape position on both sides of the front and back of the rolling mill to suck the smoke. The length of the movable exhaust hood opening (2) is 0.8 m and the width is 0.6 m. The movable exhaust hood opening (2) is connected to the air duct (6) via a rotating component; When rolling the strip steel (3), the cover opening of the movable exhaust hood (2) rotates to the side facing the working roll of the rolling mill (4) along the rolling direction; when in a non-working state, the cover opening of the movable exhaust hood (2) is turned away and is located on the side of the finishing mill; if the rolling mill is in a roll changing state, the cover opening of the movable exhaust hood (2) of the rolling mill is swung toward the side of the adjacent rolling mill.

2. The ventilation system combining spray and mobile exhaust hood according to claim 1, characterized in that: The water supply system comprises a water purification device (13), a water pump (12), a water switch control valve (15), a water filter (16), a water pressure regulator (17) and a water supply pipe (141), wherein the outlet of the water purification device (13) is connected to the header (14) via the water pump (12), the water switch control valve (15), the water filter (16), the water pressure regulator (17) and the water supply pipe (141) in sequence.

3. The ventilation system combining spray and mobile exhaust hood according to claim 1, characterized in that: The air supply system comprises an air switch control valve (20), an air filter (19), an air pressure regulator (18) and an air supply pipe (142), wherein the air switch control valve (20) is connected to the manifold (14) via the air filter (19), the air pressure regulator (18) and the air supply pipe (142) in sequence.

4. The ventilation system combining spray and mobile exhaust hood according to claim 1, characterized in that: It also includes a dust removal system and a dehydrator, and the outlet of the finishing mill main air duct (8) is connected to the dust removal system through the dehydrator.

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