Discharging structure of mist discharging fan

Abstract

The invention discloses an exhaust structure of a mist exhaust fan, which comprises an air pipe for conveying mixed gas containing rust residues and water vapor; the inlet end of the blow-off pipe is connected to the bottom of the main air pipe, and the outlet end of the blow-off pipe is connected to the drainage pipeline, so that rust residues in the air pipes enter the drainage pipeline through the blow-off pipe under the action of gravity to be discharged; the straight-through sight glass is installed on the monitoring section of the drainage pipeline and used for observing the water flow state in the drainage pipeline in real time; the overflow pipe is welded to the side wall of the drainage pipeline, and a liquid level sensor is installed on the vertical section of the overflow pipe; and the PLC control system is in signal connection with the liquid level sensor and is used for receiving the liquid level signal and triggering an alarm when the liquid level value is higher than a set liquid level threshold value. The drainage pipe is installed, rust residues in the air duct enter the drainage pipeline under the action of gravity so as to be drained away along with water, collision and friction between the rust residues and the fan impeller are avoided, the through sight glass and the liquid level sensor are additionally arranged to monitor the blockage condition of the drainage pipeline, and excessive water accumulation of the fan impeller is avoided.

Description

Technical Field

[0001] This invention relates to the field of continuous casting machine de-misting fan technology, and in particular to a de-misting fan exhaust structure. Background Technology

[0002] During the casting process of a small billet continuous casting machine, it is necessary to operate the de-misting fan to promptly remove the water mist generated by the cooling water in the secondary cooling chamber. This ensures that the water mist does not accumulate in the plant, affecting the normal operation of other equipment and the normal work of the staff. The normal operation of the de-misting fan is crucial to production. Currently, the air ducts and drainage pipes of the continuous casting machine's de-misting fan are opaque, and there is no mechanical connection between the air duct and the drainage pipe. Water vapor and rust residue in the air duct flow into the fan impeller and are then discharged from the bottom drainage pipe. The rust residue collides with the fan impeller, accelerating impeller wear and reducing its service life.

[0003] Because the air ducts and drainage pipes are opaque, staff cannot identify the operating status of the defogging fan during routine equipment inspections. They can only maintain and replace the defogging fan periodically when the machine is shut down, which can easily lead to untimely maintenance or premature replacement, increasing production risks and costs. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a mist exhaust fan structure, which mainly improves the mechanical structure of the mist exhaust fan duct and drainage pipe, and at the same time installs a liquid level sensor to provide timely alarm, reminding operators to handle faults in a timely manner, and ensuring the normal operation of the mist exhaust fan.

[0005] The technical solution adopted by this invention to solve its technical problem is: a mist exhaust fan structure, comprising:

[0006] Ductwork is used to transport mixed gases containing rust residue and moisture.

[0007] The sewage pipe has its inlet end connected to the bottom of the main air duct and its outlet end connected to the drainage pipe, so that the rust residue in the air duct can be discharged into the drainage pipe under the action of gravity.

[0008] A sight glass, installed in the monitoring section of a drainage pipe, is used to observe the water flow status inside the drainage pipe in real time.

[0009] An overflow pipe is welded to the side wall of the drainage pipe, and a liquid level sensor is installed on the vertical section of the overflow pipe to detect the liquid level height.

[0010] The PLC control system is connected to the liquid level sensor signal to receive the liquid level signal and trigger an alarm when the liquid level value is higher than the set liquid level threshold.

[0011] By setting up an independent drain pipe, rust residue is allowed to directly enter the drainage pipe, avoiding contact with the fan impeller, significantly reducing impeller wear and extending equipment lifespan; a straight-through sight glass enables real-time visual monitoring of the drainage pipe status, facilitating timely detection of blockages by maintenance personnel; the combined design of the overflow pipe and liquid level sensor can trigger an alarm by the rise in liquid level when the drainage pipe is blocked, preventing motor overload caused by water accumulation on the fan impeller; the introduction of the PLC control system enables automated monitoring and alarms, improving system response speed and reliability.

[0012] As a further improvement of the present invention: the drain pipe is a flexible metal hose. The flexible metal hose has good flexibility and corrosion resistance, can adapt to the vibration and high-temperature environment of the ductwork, and ensures long-term stable operation; the hose structure is easy to install and adjust, and can adapt to the connection needs of ductwork and drainage pipes with different layouts.

[0013] As a further improvement of the present invention: the air duct is provided with a guide section, the guide section is inclined relative to the ground, and the inlet end of the sewage pipe is located at the lowest end of the guide section.

[0014] As a further improvement of the present invention: the air duct is provided with a guide section, the guide section is arranged in an arc bend, and the inlet end of the sewage pipe is located in the middle of the guide section.

[0015] As a further improvement of the present invention: both ends of the through-view mirror are connected to the drainage pipes via flanges.

[0016] As a further improvement of the present invention: a detachable filter assembly is provided at the connection between the sewage pipe and the bottom of the air duct. The filter assembly includes a filter screen and a frame for fixing the filter screen. The filter screen intercepts and stores larger particles of rust residue.

[0017] As a further improvement of the present invention: a protective cover is slidably fitted on the outer periphery of the through-view mirror, and the inner diameter of the protective cover is larger than the outer diameter of the flange.

[0018] As a further improvement of the present invention: the downstream section of the drainage pipe is provided with a high-pressure flushing branch, the inlet of the high-pressure flushing branch is connected to a high-pressure water supply source, and the outlet of the high-pressure flushing branch is connected to the drainage pipe in the counter-current direction.

[0019] When the level sensor triggers a blockage alarm or the PLC system detects a periodic decrease in flow rate, the high-pressure flushing program is automatically started.

[0020] The flushing pressure is set to 5-10 MPa, and the jet is continuously sprayed for 10-30 seconds to create a reverse pulse water flow that impacts the sediment.

[0021] After flushing, the pipe patency is verified through a sight glass. If the liquid level does not return to normal, the process is upgraded to manual maintenance.

[0022] As a further improvement of the present invention: the high-pressure flushing branch is equipped with a double check valve assembly and a pressure relief valve.

[0023] As a further improvement of the present invention: a flushing nozzle is installed at the outlet of the high-pressure flushing branch, and a spiral guide vane is provided inside the flushing nozzle.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention installs a drain pipe between the air duct and the drainage pipe, allowing rust residue in the air duct to enter the drainage pipe under gravity and be discharged with the water, thus avoiding collision and friction between the rust residue and the fan impeller and reducing the wear of the fan impeller.

[0026] 2. Adding a straight-through sight glass facilitates observation of water flow during routine equipment inspections, making it easier to confirm whether the drainage pipe is blocked. The liquid level sensor monitors the drainage pipe for blockages, and an alarm is triggered in time to remind staff to clear the drainage pipe promptly. This prevents excessive water accumulation on the fan impeller, which increases the load on the misting fan, exacerbates motor heating, and can cause the motor to burn out and short-circuit. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 This is a schematic diagram of the inclined guide section provided on the air duct of the present invention.

[0029] Figure 3 This is a schematic diagram of the structure of the air duct with an arc-shaped guide section in this invention.

[0030] Figure label:

[0031] 1. Air duct, 2. Sewage pipe, 3. Mist exhaust fan, 4. Straight-through sight glass, 5. Liquid level sensor, 6. Overflow valve. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] In order to solve the technical problems in the prior art, the present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0034] like Figure 1As shown, this invention discloses a mist exhaust fan structure, comprising: a duct 1 for conveying a mixed gas containing rust residue and water vapor; a drain pipe 2, the inlet end of which is connected to the bottom of the main duct 1, and the outlet end of which is connected to a drainage pipe, so that the rust residue in the duct 1 is discharged into the drainage pipe through the drain pipe 2 under gravity; a sight glass 4, installed on the monitoring section of the drainage pipe for real-time observation of the water flow status in the drainage pipe; an overflow pipe, welded to the side wall of the drainage pipe, with a liquid level sensor 5 installed on the vertical section of the overflow pipe for detecting the liquid level height; and a PLC control system, connected to the liquid level sensor 5 for receiving the liquid level signal and triggering an alarm when the liquid level value is higher than a set liquid level threshold.

[0035] Rust residue is directly diverted through drain pipe 2 to achieve directional separation of rust residue, preventing it from entering the fan impeller and reducing the risk of impeller wear. Straight-through sight glass 4 provides visual monitoring, allowing maintenance personnel to judge the pipeline status without stopping the machine, thus improving inspection efficiency. Overflow pipe and liquid level sensor 5 form a U-shaped liquid level monitoring structure, which, together with the PLC system, constitutes an intelligent alarm that can trigger a response in the early stage of blockage, avoiding motor overload.

[0036] The components, including duct 1, drain pipe 2, straight-through sight glass 4, overflow pipe, and PLC control system, form a triple protection system of "mechanical separation - manual observation - automatic protection." These components work together to prevent impeller wear and water overload, comprehensively improving the fan's operational stability.

[0037] Furthermore, the sewage pipe 2 is made of flexible metal hose.

[0038] The sewage pipe 2 is made of flexible metal hose. Stainless steel corrugated pipe can also be used, as it can withstand fan vibration and high temperature and humidity environments, avoiding the risk of pipe rupture. At the same time, the hose structure facilitates installation and adjustment, compensates for positional deviations between duct 1 and the drainage pipe, and reduces assembly difficulty.

[0039] In the exhaust fan 3 duct, rust residue generated in the pipes flows through the metal flexible hose connected to duct 1 and is discharged into the drain pipe due to gravity. This avoids collision and friction between the rust residue and the fan impeller, reducing wear on the impeller. During routine equipment inspections, staff can more easily check for blockages in the drain pipe by observing the water flow through the sight glass 4, preventing water accumulation on the fan impeller.

[0040] Meanwhile, an overflow pipe is added to the drainage pipe, and a liquid level sensor 5 is installed on the overflow pipe. When the drainage pipe is blocked, the water level in the overflow pipe will rise due to the U-shaped pipe principle. When the liquid level rises to the specified level, the liquid level sensor 5 will be triggered, and a voice alarm will be sounded in the main control room to promptly remind the staff to unclog the drainage pipe and avoid excessive water accumulation in the impeller of the fan, which would increase the load on the motor of the fan 3, aggravate the motor's heating, cause the motor to burn out and short-circuit, and in severe cases, cause the entire casting machine's power system to trip.

[0041] In some embodiments, a detachable filter assembly is provided at the connection between the metal flexible hose and the bottom of the air duct 1. The filter assembly includes a filter screen and a frame. The mesh size of the filter screen is screened to effectively intercept larger rust particles and prevent them from entering the metal flexible hose and causing blockage. The frame is adapted to the bottom of the air duct 1 and the connection part of the metal flexible hose, making it easy to disassemble and clean regularly.

[0042] The filter components intercept large particles of debris, preventing blockage of the drain pipe 2 and extending the system maintenance cycle.

[0043] In some implementations, a straight-through sight glass 4 is used in the middle section of the drainage pipe to connect with the original iron pipe through a flange. The straight-through sight glass 4 is made of transparent and high-strength glass. The flanges at both ends of the sight glass are completely matched with the flanges of the iron pipe of the drainage pipe in terms of size and bolt hole position. A tight connection is achieved through a gasket and fastening bolts, which allows the staff at the station to clearly observe the water accumulation in the fan impeller, providing convenience for daily equipment inspection.

[0044] Furthermore, a protective cover is slidably fitted around the outer periphery of the through-view mirror 4, and the inner diameter of the protective cover is larger than the outer diameter of the flange.

[0045] The protective cover prevents the sight glass from being damaged by external forces, while not affecting observation and improving equipment reliability. The operator can slide the protective cover to expose the straight-through sight glass 4 for observing the internal condition of the drainage pipe; the operation is simple.

[0046] In some implementations, a non-contact liquid level sensor 5 is used, which works by sensing the capacitance of the liquid in the overflow pipe or by ultrasonic reflection. The liquid level sensor 5 is installed on the side of the overflow pipe close to the drainage pipe, and its sensing part is sealed to the overflow pipe wall to ensure accurate and stable operation in harsh water vapor environment. When the liquid level rises to the designated position, the liquid level sensor 5 is triggered and sends a signal to the main control room.

[0047] In some implementations, such as Figure 2 As shown, the air duct 1 is provided with a guide section, which is inclined relative to the ground, and the inlet end of the sewage pipe 2 is located at the lowest end of the guide section.

[0048] Duct 1 is equipped with an inclined guide section, and the inlet of sewage pipe 2 is located at the lowest point of the guide section. The inclined structure uses gravity to accelerate the collection of residue, so that more rust residue is concentrated at the inlet of sewage pipe 2. The slope of the guide section ensures that the residue does not stagnate or slide, and eliminates turbulence noise caused by local accumulation in duct 1.

[0049] The slope of the diversion section can be set gently; specifically, the angle of inclination of the diversion section relative to the ground is between 25° and 45°.

[0050] In some implementations, such as Figure 3 As shown, the duct 1 is provided with a guide section, which is arranged in an arc shape. The inlet end of the sewage pipe 2 is located in the middle of the guide section. Specifically, the middle of the arc-shaped guide section can protrude upwards or downwards. Of course, the arc-shaped section can also protrude horizontally forwards or backwards.

[0051] Duct 1 has an arc-shaped bend guiding section, and the inlet of sewage pipe 2 is located in the middle. The arc structure generates centrifugal force, causing rust residue to accumulate on the pipe wall in advance. The inlet of sewage pipe 2, located in the middle of the guiding section, can capture residue in the airflow.

[0052] In some embodiments, the downstream section of the drainage pipe is provided with a high-pressure flushing branch, the inlet of which is connected to a high-pressure water supply source, and the outlet of which is connected to the drainage pipe in the counter-current direction.

[0053] When the level sensor 5 triggers a blockage alarm or the PLC system detects a periodic decrease in flow rate, the high-pressure flushing program is automatically started:

[0054] The flushing pressure is set to 5-10 MPa, and the jet is continuously sprayed for 10-30 seconds to create a reverse pulse water flow that impacts the sediment.

[0055] After flushing, verify the pipe patency through sight glass 4. If the liquid level does not return to normal, proceed to manual maintenance.

[0056] The high-pressure flushing branch is connected to the main drainage pipe via a flange; the added high-pressure flushing branch adopts a reverse jet design, with high-pressure water flow impacting from the downstream to the upstream of the drainage pipe to clear blockages in the drainage pipe.

[0057] Furthermore, design a multi-mode flushing logic:

[0058] Automatic mode: The PLC system is associated with the liquid level sensor 5 signal. When the liquid level exceeds the limit for ≥2 minutes, flushing is automatically triggered. The flushing frequency is dynamically adjusted based on historical blockage data. When the average daily blockage exceeds 3 times, daily preventive flushing is initiated.

[0059] High-pressure flushing and drainage are controlled in a coordinated manner. The liquid level sensor alarms at level 5 → the PLC starts high-pressure flushing → the pneumatic valve opens the spray → the flow meter verifies the water flow recovery → if the unblocking is successful, the system is reset.

[0060] Manual mode: A physical flushing button is installed in the control box of the drainage pipe, which can be used by maintenance personnel to force high-pressure flushing; during manual flushing, the operator ID and timestamp are automatically recorded and synchronized to the maintenance database.

[0061] Maintenance personnel manually start flushing with a button → the system disables automatic power-off logic → flushing pressure curve is displayed in real time → a flushing report is generated upon completion of the operation.

[0062] In some embodiments, the high-pressure flushing branch is equipped with a double check valve assembly to prevent sewage from flowing back into the water supply system; the flushing pipeline is equipped with a pressure relief valve that automatically releases pressure when the pressure exceeds 12MPa to protect the pipeline structure.

[0063] Furthermore, a flushing nozzle is installed at the outlet of the high-pressure flushing branch, and the flushing nozzle is equipped with a spiral guide vane, i.e., a rotary nozzle is installed.

[0064] An overload protection device is installed at the motor of the de-misting fan 3. This device includes a current detection module, a control unit, and an actuator. The current detection module is integrated into the fan motor power supply circuit and uses a Hall effect sensor. The module monitors the motor operating current of the de-misting fan 3 in real time. When the drainage pipe is blocked, causing an increase in motor load and the current exceeds a set threshold, the control unit receives the signal from the current detection module and controls the actuator to cut off the motor power supply. This prevents the motor from burning out and short-circuiting due to overload and ensures the stable operation of the entire casting machine's power system. The current detection module is connected to the PLC control system. When the current exceeds the set threshold, an alarm signal is sent to remind the operator to check the system.

[0065] When the fan is running, the residue is directly discharged into the drainage pipe through the flow guide module (sewage pipe 2). The operator monitors the water flow status through the straight-through sight glass 4. If a blockage occurs, the accumulated water rushes into the overflow pipe and triggers the liquid level sensor 5. The PLC system immediately starts the alarm and records the fault data. Based on the alarm information and the observation results of the sight glass, the maintenance personnel unclog the pipe by cleaning the cover or replace the metal hose, forming a closed loop of operation-monitoring-maintenance.

[0066] Implementation Case 1:

[0067] like Figure 1 As shown, this embodiment of the invention discloses a mist exhaust fan discharge structure. A metal flexible hose 2 is connected to the bottom of the duct 1 of the mist exhaust fan 3 and connected to the drainage pipe. A straight-through sight glass 4 is used to connect the drainage pipe to the original iron pipe flange in the middle part. At the same time, an overflow pipe is added to the drainage pipe, and a liquid level sensor 5 and an overflow valve 6 are installed on the overflow pipe.

[0068] In this embodiment, rust residue falling into duct 1 flows directly from the metal hose into the drainage pipe and is discharged as water vapor flows, avoiding collision and friction between the rust residue and the fan impeller, thus reducing wear on the fan impeller. The straight-through sight glass 4 facilitates observation of water accumulation in the fan impeller, providing convenience for equipment inspection by on-site personnel.

[0069] When the drainage pipe becomes blocked, the water level in the overflow pipe will rise due to the U-shaped pipe principle as the water in the impeller of the de-fogging fan 3 rises. When the water level reaches the specified level, it will trigger the signal of the level sensor 5 and issue a voice alarm in the main control room, reminding the staff to clear the drainage pipe in time. This is to prevent excessive water accumulation in the impeller of the fan, which would increase the load on the motor of the de-fogging fan 3, aggravate the motor's heat generation, and easily cause the motor to burn out and short-circuit. In severe cases, it could cause a power outage in the entire casting machine's power system, affecting the stable operation of production.

[0070] The main functions of this invention are:

[0071] 1. In the exhaust fan duct, rust residue entering the pipe will be discharged into the drain pipe due to gravity at the metal flexible hose connected to the duct, thus avoiding collision and friction between the rust residue and the fan impeller and reducing the wear of the fan impeller.

[0072] 2. During routine equipment inspections, staff can more easily check for blockages in drainage pipes by observing the water flow through the sight glass, thus preventing water accumulation on the fan impeller.

[0073] 3. In the event of a blockage in the drainage pipe, the system can detect the blockage through a liquid level sensor signal and issue a voice alarm in the main control room. This will promptly remind staff to clear the drainage pipe and prevent excessive water accumulation in the fan impeller, which could increase the load on the misting fan motor, exacerbate motor overheating, cause the motor to burn out and short-circuit, and affect production stability.

[0074] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A mist exhaust fan structure, characterized in that, include: Ductwork is used to transport mixed gases containing rust residue and moisture. The sewage pipe has its inlet end connected to the bottom of the main air duct and its outlet end connected to the drainage pipe, so that the rust residue in the air duct can be discharged into the drainage pipe under the action of gravity. A sight glass, installed in the monitoring section of a drainage pipe, is used to observe the water flow status inside the drainage pipe in real time. An overflow pipe is welded to the side wall of the drainage pipe, and a liquid level sensor is installed on the vertical section of the overflow pipe to detect the liquid level height. The PLC control system is connected to the liquid level sensor signal to receive the liquid level signal and trigger an alarm when the liquid level value is higher than the set liquid level threshold.

2. The exhaust structure of a mist exhaust fan according to claim 1, characterized in that, The sewage pipe is a flexible metal hose.

3. The exhaust structure of a mist exhaust fan according to claim 1 or 2, characterized in that, The duct is provided with a guide section, which is inclined relative to the ground, and the inlet end of the sewage pipe is located at the lowest end of the guide section.

4. The exhaust structure of a mist exhaust fan according to claim 1 or 2, characterized in that, The duct is provided with a guide section, which is arranged in an arc bend, and the inlet end of the sewage pipe is located in the middle of the guide section.

5. The exhaust structure of a mist exhaust fan according to claim 1, characterized in that, Both ends of the through-view mirror are connected to the drainage pipe via flanges.

6. The exhaust structure of a mist exhaust fan according to claim 1, characterized in that, A detachable filter assembly is provided at the connection between the sewage pipe and the bottom of the air duct. The filter assembly includes a filter screen and a frame for fixing the filter screen. The filter screen intercepts and stores larger particles of rust residue.

7. The exhaust structure of a mist exhaust fan according to claim 5, characterized in that, A protective cover is slidably fitted around the outer periphery of the through-view mirror, and the inner diameter of the protective cover is larger than the outer diameter of the flange.

8. The exhaust structure of a mist exhaust fan according to claim 1, characterized in that, The downstream section of the drainage pipe is equipped with a high-pressure flushing branch. The inlet of the high-pressure flushing branch is connected to a high-pressure water supply source, and the outlet of the high-pressure flushing branch is connected to the drainage pipe in the counter-current direction. When the level sensor triggers a blockage alarm or the PLC system detects a periodic decrease in flow rate, the high-pressure flushing program is automatically started. The flushing pressure is set to 5-10 MPa, and the jet is continuously sprayed for 10-30 seconds to create a reverse pulse water flow that impacts the sediment. After flushing, the pipe patency is verified through a sight glass. If the liquid level does not return to normal, the process is upgraded to manual maintenance.

9. The exhaust structure of a mist exhaust fan according to claim 8, characterized in that, The high-pressure flushing branch is equipped with a double check valve assembly.

10. The exhaust structure of a mist exhaust fan according to claim 1, characterized in that, An overflow valve is installed on the overflow pipe.

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