Chimney ignition extinguishing protection device

Abstract

A chimney ignition extinguishing protection device comprises an ignition device arranged at the bottom of a chimney of a hot blast stove and a pneumatic fuel gas quick-closing valve capable of continuously providing fuel gas for the ignition device. The detection assembly comprises an observation pipe used for observing the ignition condition of the ignition device, a flame detection probe connected with the observation pipe and provided with a photoelectric sensor, and a photoelectric sensor used for converting collected ultraviolet and infrared wavelength signals generated by flame in the chimney into electric signals; and the flame detection amplifier is used for enhancing the electric signal output by the photoelectric sensor. The chimney ignition and extinguishment protection device further comprises an integrated control box which is in telecommunication connection with the detection assembly, the control center and the pneumatic gas quick-closing valve. According to the utility model, the traditional manual timing inspection is improved into real-time detection, so that flameout of the ignition device can be found in time, a gas source is automatically cut off, and accidents and risks caused by the fact that flameout is not found in time are completely eradicated.

Description

Technical Field

[0001] This utility model relates to the field of hot blast stove equipment for metallurgical blast furnaces, and in particular to a chimney ignition and extinction protection device and method. Background Technology

[0002] A hot blast stove is a large piece of equipment used to heat the blast furnace in metallurgy. For a hot blast stove to work properly, it is necessary not only to supply the furnace with sufficient fuel and air for combustion, but also to remove the high-temperature exhaust gas generated by combustion, i.e., flue gas, from the furnace. Therefore, a chimney is an essential piece of equipment for a hot blast stove.

[0003] The difference in gas density between the inside and outside of the chimney due to temperature differences creates a pressure difference. This pressure difference, known as chimney draft, overcomes resistance and propels the flue gas flow, maintaining normal gas flow and heat exchange within the hot blast stove. The negative pressure at the bottom of the chimney is the reason for this draft.

[0004] The main factors affecting chimney draft are chimney height, external air temperature, and flue gas temperature. On-site operators cannot change the first two factors; the only controllable factor is the flue gas temperature. However, when the blast furnace is shut down, the hot blast stove stops working and cannot produce high-temperature flue gas. As time goes on, the temperature inside the chimney gradually decreases, thus affecting the chimney draft. To ensure that the chimney draft is not excessively affected before production resumes, on-site operators usually manually ignite the chimney at the bottom during the shutdown period to maintain the temperature inside the chimney.

[0005] However, the chimney ignition devices currently used by on-site operators are quite primitive. They mainly consist of a metal ventilation burner, a metal ignition device, a manual flare plate, and a manual gas shut-off valve. After ignition, operators periodically check the flame status; if the flame goes out, they re-ignite. If the flameout is not detected in time, a large amount of coke oven gas will accumulate at the bottom of the chimney. Since the density limit for coke oven gas to explode is 5%-30%, meaning its lower explosive limit is low and its explosive range is wide, an explosive mixture can easily form inside the chimney. This mixture is highly susceptible to explosion upon contact with an ignition source, creating a very unsafe situation. Utility Model Content

[0006] To address the aforementioned problems, the purpose of this utility model is to provide a chimney ignition failure protection device. This device can monitor the flame status of the chimney ignition device in real time during blast furnace shutdown. If the chimney ignition fails, the gas supply can be immediately cut off, thereby ensuring the safety of the blast furnace chimney.

[0007] To achieve the above objectives, the technical solution of the chimney ignition and flameout protection device of this utility model is as follows:

[0008] A chimney ignition failure protection device, characterized in that it includes:

[0009] An ignition device (ignition gun) is installed at the bottom of the hot blast stove chimney. This chimney ignition device is connected to a pneumatic gas quick-closing valve located outside the furnace that can continuously supply gas.

[0010] A detection component is installed at the outer lining plate of the air box at the bottom of the hot blast stove chimney, the detection component comprising:

[0011] An observation tube that extends into the bottom of the chimney to observe the ignition status of the ignition device.

[0012] The flame detector probe connected to the observation tube is equipped with a photoelectric sensor, which converts the ultraviolet and infrared wavelength signals generated by the flame inside the chimney into electrical signals.

[0013] A fire detection amplifier that enhances the electrical signal output from the photoelectric sensor.

[0014] An integrated control box for telecommunications connection detection components, control center, and pneumatic gas quick-closing valve.

[0015] The chimney ignition and flameout protection device according to this utility model is characterized in that:

[0016] The photoelectric sensor and fire detector amplifier output ultraviolet and infrared wavelength signals, which are converted into electrical signals, to the integrated control box via shielded cables.

[0017] The chimney ignition and flameout protection device according to this utility model is characterized by:

[0018] The integrated control box is equipped with an indicator light that illuminates to indicate "flame detection is active" and an indicator light that illuminates to indicate "flame detection malfunction" when no electrical signal is generated.

[0019] The chimney ignition and flameout protection device according to this utility model is characterized by:

[0020] A chrysanthemum-shaped plate that can rotate to change the amount of combustion air intake is installed at the air inlet of the ignition device located on the outer shroud of the air box.

[0021] The chimney ignition and flameout protection device according to this utility model is characterized by:

[0022] The gas pipe for supplying the ignition gun is inserted into the central through hole of the chrysanthemum-shaped plate. Around the central through hole are two chrysanthemum-shaped panels that can be rotated separately. The two chrysanthemum-shaped panels are spaced apart with fan-shaped holes that allow air to pass through. By rotating the chrysanthemum-shaped panels at different angles, fan-shaped holes with different cross-sectional areas can be formed from the two chrysanthemum-shaped panels. The air channels formed by the fan-shaped holes are used to pass combustion air, thereby adjusting the amount of combustion air intake.

[0023] Therefore, in conjunction with the draft of the chimney, the adjustable chrysanthemum-shaped plate can adjust the air intake to ensure complete combustion of the ignition device.

[0024] The chimney ignition and flameout protection device according to this utility model is characterized by:

[0025] To reduce the possibility of false alarms, a time-delay relay is installed in the integrated control box.

[0026] Therefore, a "flame detection fault" signal can be issued after a few seconds when the electrical signals of the ultraviolet and infrared wavelengths of the flame cannot be collected temporarily.

[0027] The chimney ignition and flameout protection device according to this utility model is characterized in that:

[0028] The on-site integrated control box is also equipped with a "protection activation" switch for flame detection. The "protection activation" switch is turned off before ignition. After the chimney is ignited, the "protection activation" switch is turned on, the "flame detection light" illuminates, and the gas quick-closing valve remains open.

[0029] The chimney ignition and flameout protection device according to this utility model is characterized in that:

[0030] The ignition device and the flame detection device are separated by a steel plate.

[0031] To prevent the flame detection device and cables from being burned by high temperatures when the ignition device is inserted.

[0032] Advantages of this utility model:

[0033] Because of the adoption of a chimney ignition failure protection device, the traditional manual timed inspection has been improved to real-time detection, which can promptly detect ignition device failure and automatically cut off the gas supply, eliminating the huge risk of a large amount of flammable gas accumulating at the bottom of the chimney due to failure to detect ignition failure in time. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the chimney ignition and extinguishing protection device of this utility model.

[0035] Figure 2 , Figure 3 These are three-dimensional views of the rotatable chrysanthemum-shaped plate located at the ignition device insertion port.

[0036] Figure 4 This is the logic control flowchart of the chimney ignition and extinguishing protection device of this utility model.

[0037] Figure 5 Electrical schematic diagram of the internal circuitry of the field integration control box.

[0038] Figure 6 This is the detection control circuit for the flame detection probe (flame detector).

[0039] Figure 7 Electrical schematic diagram of the internal circuitry of the field integration control box. Detailed Implementation

[0040] A chimney ignition and flameout protection device includes:

[0041] An ignition device is installed at the bottom of the hot blast stove chimney. This chimney ignition device is connected to a pneumatic gas quick-closing valve located outside the furnace that can continuously supply gas.

[0042] A detection component is installed at the outer lining plate of the air box at the bottom of the hot blast stove chimney, the detection component comprising:

[0043] An observation tube that extends into the bottom of the chimney to observe the ignition status of the ignition device.

[0044] The flame detector probe connected to the observation tube is equipped with a photoelectric sensor, which converts the ultraviolet and infrared wavelength signals generated by the flame inside the chimney into electrical signals.

[0045] A fire detection amplifier that enhances the electrical signal output from the photoelectric sensor.

[0046] The integrated control box for telecommunications connection detection components, control center and pneumatic gas quick-closing valve detects and judges the ignition status of the ignition device and controls the combustion air flow.

[0047] Sufficient combustion air is required after the chimney is ignited; otherwise, the ignition gun will also extinguish. Therefore, the ignition device is equipped with a rotatable daisy-shaped plate at the ignition gun insertion port.

[0048] like Figure 2 As shown in Figure 3, the gas pipe for supplying the ignition gun is inserted into the central through hole of the chrysanthemum-shaped plate. Around the central through hole are two chrysanthemum-shaped panels that can be rotated separately. The two chrysanthemum-shaped panels are spaced apart with fan-shaped holes that allow air to pass through. By rotating the chrysanthemum-shaped panels at different angles, fan-shaped holes with different cross-sectional areas can be formed from the two chrysanthemum-shaped panels. The air channels formed by the fan-shaped holes are used to pass combustion air, thereby adjusting the amount of combustion air intake.

[0049] Figure 6The detection control loop of the flame detection probe utilizes the photoelectric sensing element of the probe to collect ultraviolet and infrared wavelength signals generated by the flame inside the chimney, converting them into electrical signals. These signals are then transmitted via shielded cable to the integrated control box on-site. The electrical signal is amplified by a flame detector amplifier. The amplifier's output signal illuminates a "flame detected" indicator in the integrated control box, indicating a normal flame. When the probe fails to detect ultraviolet and infrared wavelengths from the flame inside the chimney and no electrical signal is generated, a "flame detection fault" indicator illuminates, indicating the fire is extinguished. To reduce the possibility of false alarms, a time-delay relay is installed in the integrated control box; that is, a "flame detection fault" signal is issued 5 seconds after the probe fails to collect the ultraviolet and infrared wavelength electrical signals from the flame.

[0050] The internal electrical principle of the field integrated control box is as follows: Figure 5 As shown in Figure 7, the "Protection Enable" selector switch for the flame detector is set. Before ignition, the protection is disabled; otherwise, the gas quick-closing valve cannot open. After chimney ignition is complete, the protection is enabled, the "Flame Detector Has Flame" light illuminates, and the gas quick-closing valve remains open. When the "Flame Detector Fault" light illuminates, the gas quick-closing valve immediately closes, cutting off the gas supply.

[0051] The entire chimney ignition failure protection system can be integrated into a DCS (Distributed Control System). Central control personnel can detect chimney ignition failure via audible and visual alarms and the closing of the gas quick-shutdown valve, instructing on-site personnel to go to the chimney to confirm and prepare for re-ignition. This truly achieves real-time monitoring and immediate response, leaving no blind spots.

Claims

1. A chimney ignition failure protection device, characterized in that: include: An ignition device is installed at the bottom of the hot blast stove chimney. This chimney ignition device is connected to a pneumatic gas quick-closing valve located outside the furnace that continuously supplies gas. A detection component is installed at the outer lining plate of the air box at the bottom of the hot blast stove chimney, the detection component comprising: An observation tube that extends into the bottom of the chimney to observe the ignition status of the ignition device. The flame detector probe connected to the observation tube is equipped with a photoelectric sensor, which converts the ultraviolet and infrared wavelength signals generated by the flame inside the chimney into electrical signals. A fire detection amplifier that enhances the electrical signal output from the photoelectric sensor. The integrated control box for telecommunications connection detection components, control center and pneumatic gas quick-closing valve detects and judges the ignition status of the ignition device and controls the combustion air flow.

2. The chimney ignition and flameout protection device according to claim 1, characterized in that: The photoelectric sensor and fire detector amplifier output ultraviolet and infrared wavelength signals, which are converted into electrical signals, to the integrated control box via shielded cables.

3. The chimney ignition and flameout protection device according to claim 1, characterized in that: The integrated control box is equipped with an indicator light that illuminates to indicate "flame detection is active" and an indicator light that illuminates to indicate "flame detection malfunction" when no electrical signal is generated.

4. The chimney ignition and flameout protection device according to claim 1, characterized in that: A chrysanthemum-shaped plate that can rotate to change the amount of combustion air intake is installed at the air inlet of the ignition device located on the outer shroud of the air box.

5. The chimney ignition and flameout protection device according to claim 4, characterized in that: The gas pipe for supplying the ignition gun is inserted into the central through hole of the chrysanthemum-shaped plate. Around the central through hole are two chrysanthemum-shaped panels that can be rotated separately. The two chrysanthemum-shaped panels are spaced apart with fan-shaped holes that allow air to pass through. By rotating the chrysanthemum-shaped panels at different angles, fan-shaped holes with different cross-sectional areas can be formed from the two chrysanthemum-shaped panels. The air channels formed by the fan-shaped holes are used to pass combustion air, thereby adjusting the amount of combustion air intake.

6. The chimney ignition and flameout protection device according to claim 1, characterized in that: To reduce the possibility of false alarms, a time-delay relay is installed in the integrated control box.

7. The chimney ignition and flameout protection device according to claim 3, characterized in that: The on-site integrated control box is also equipped with a "protection activation" switch for flame detection. The "protection activation" switch is turned off before ignition. After the chimney is ignited, the "protection activation" switch is turned on, the "flame detection light" illuminates, and the gas quick-closing valve remains open.

8. The chimney ignition and flameout protection device according to claim 1, characterized in that: The ignition device and the flame detection device are separated by a steel plate.

Images