Flame detector for heating furnace of propane dehydrogenation device

Abstract

The utility model belongs to the technical field of flame detectors, and particularly relates to a flame detector for a heating furnace of a propane dehydrogenation device, which comprises a flame detector body, a mounting flange, a heat insulation pipe, a sealing window, a first double nipple, a three-way pipe, a second double nipple, a universal joint base, an explosion-proof junction box and a central room cabinet, the flame detector body, the mounting flange, the heat insulation pipe, the sealing window, the first double nipple, the three-way pipe, the second double nipple and the universal joint base are connected in sequence, the anti-explosion junction box is connected with the flame detector body through a cable, and the anti-explosion junction box is electrically connected with a central room cabinet. The lens of the flame detector is not easy to damage, and the flame detection result is accurate after the flame detector is used for a long period.

Description

Technical Field

[0001] The utility model belongs to the technical field of flame detectors, and particularly relates to a flame detector for a heating furnace of a propane dehydrogenation unit. Background Art

[0002] Since the fuel gas of the heating furnace in the PDH unit involves fuel gases such as methane, ethane, and hydrogen, an ion rod flame detector is adopted for the heating furnace flame detector. However, the ion rod is affected by harsh environments such as high temperature, strong corrosion, and hydrogen embrittlement, and the use effect is not obvious, unable to meet the long-term trouble-free operation of users. With the development of the times and the miniaturization of electronic components, the integrated ultraviolet and infrared detector has a fast measurement response speed, fixed-point detection, and low price, and is not affected by the combustion medium of the burner. The ultraviolet and infrared detector has relatively high stability. However, in a harsh environment, the photosensitive element will soon be contaminated with oil and dust, and even if purged with air, it can no longer detect the flame correctly. Due to such technical defects of the flame detector, coupled with the problem that the fire detector itself cannot well solve the high-temperature resistance problem, phenomena such as lens burnout, light guide burnout, and signal cable burnout often occur, which not only increases the operation cost but also increases the on-site maintenance workload, resulting in major hidden dangers to varying degrees in the fire extinguishing protection device. Content of the Utility Model

[0003] The purpose of the utility model is to solve the problem that the flame detector described in the above background art cannot be used for a long period and the lens is easily damaged. Here, a flame detector for a heating furnace of a propane dehydrogenation unit is proposed. The lens of the flame detector for the heating furnace of the propane dehydrogenation unit is not easily damaged, and the flame detection result is accurate after long-term use.

[0004] The technical solution adopted to achieve the above purpose is a flame detector for a heating furnace of a propane dehydrogenation unit. The flame detector for the heating furnace of the propane dehydrogenation unit includes a flame detector body, a mounting flange, a heat-insulating pipe, a sealing window, a first pair of screws, a three-way pipe, a second pair of screws, a universal joint base, an explosion-proof junction box, and a central control room cabinet. The flame detector body, the mounting flange, the heat-insulating pipe, the sealing window, the first pair of screws, the three-way pipe, the second pair of screws, and the universal joint base are connected in sequence. The explosion-proof junction box is connected to the flame detector body through a cable, and the explosion-proof junction box is electrically connected to the central control room cabinet.

[0005] In the above technical solution, a sealing window is installed on the lens side of the flame detector body. This sealing window can block the dirt, debris, or heat blown back, so that heat, water vapor, etc. will not accumulate on the lens of the flame detector body, playing a role in protecting the lens and reducing the influence of the harsh environment on the detection effect. The flame detector is installed through the universal joint base, and thus, by adjusting the angle, the loss of the flame signal can be avoided.

[0006] Further, one end of the tee is connected to the instrument air pipeline, and a rotameter and a filter pressure reducing valve are provided on the instrument air pipeline.

[0007] In the above technical solution, nitrogen or other gases are introduced into the tee through the instrument air pipeline to blow dirt and other impurities, preventing the influence on the flame detector detection and taking away heat.

[0008] Further, the sealing window is made of quartz.

[0009] In the above technical solution, the sealing window needs to allow ultraviolet radiation to pass through, otherwise it will affect the flame detector's detection of the flame condition.

[0010] Further, the cable is an armored cable, and a quick-release joint is provided at the end of the cable.

[0011] In the above technical solution, the armored cable has good high-temperature resistance to avoid damage to the cable due to high temperature.

[0012] Further, the flame detector body includes a flame sensor, a switch relay, a gain selector, two flash frequency filters, a switch timer, and an output unit. The flame sensor is connected to the switch relay, and the switch relay is respectively connected to the gain selector, the switch timer, and the two flash frequency filters. The two flash frequency filters are connected to the output unit.

[0013] In the above technical solution, the flame sensor is used to convert the optical signal of the flame into an electrical signal. The gain selector is used to control the amplitude increase of the electrical signal to avoid the inability to process the weak flame signal. The electrical signal is distributed into a high-gain range signal and a low-gain range signal through the switch relay. The flash frequency filter can correctly filter the environmental signal to avoid affecting the result accuracy. Since the flame signal is a flashing signal and may disappear, the switch timer is used to filter the short flame disappearance signal to prevent obtaining a wrong result of the heating furnace flameout.

[0014] Further, the flame detector body further includes a self-checking circuit and a timer circuit. The flash frequency filter is respectively connected to the self-checking circuit and the timer circuit, and the self-checking circuit is connected to the switch timer.

[0015] Further, the flame detector body further includes a flame relay, and the flame relay is connected to the self-checking circuit.

[0016] In the above technical solution, the flame relay is used to output the signal obtained by the self-checking circuit.

[0017] Further, the output unit includes an analog signal display unit and an LED bar display unit.

[0018] In the above technical solution, the obtained flame signal is presented in an intuitive form, facilitating the understanding of the staff.

[0019] Furthermore, the flame sensor is an infrared and ultraviolet composite sensor.

[0020] The advantages of the present utility model are as follows:

[0021] 1. The present utility model adopts a quartz integrated sealed window to discharge factors affecting the flame detection result, such as dirt, debris, or heat generated by the heating furnace, and protects the lens of the flame detector body.

[0022] 2. The present utility model uses a gimbal base to install the flame detector, and the installation position of the gimbal base can be adjusted to avoid aiming at the target flame horizontally from the center line of the burner, so as to avoid signal loss caused by the instantaneous movement of the flame.

[0023] 3. The present utility model amplifies the flame signal through a gain selector and filters the ambient signal through a flicker frequency filter to ensure that the flame signal is within the selected frequency range and further calculated. Through the setting of the timer and self-checking circuit, incorrect output results are avoided, making the final flame signal detection result more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0025] Figure 1 It is a component composition diagram of the flame detector for the heating furnace of the propane dehydrogenation device of the present utility model;

[0026] Figure 2 It is a circuit connection diagram of the flame detector body of the present utility model.

[0027] Illustration: 1. Flame detector body, 2. Installation flange, 3. Heat insulation pipe, 4. Sealed window, 5. First pair of threads, 6. Three-way pipe, 7. Second pair of threads, 8. Gimbal base, 9. Cable, 11. Flame sensor, 12. Switch relay, 13. Gain selector, 14. Flicker frequency filter, 15. Switch timer, 16. Self-checking circuit, 17. Timer circuit, 18. Flame relay, 19. Analog signal display unit, 20. LED column display unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model rather than all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present utility model.

[0029] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0030] As Figure 1 shown, a flame detector for a heating furnace of a propane dehydrogenation device, the flame detector for the heating furnace of the propane dehydrogenation device is composed of a flame detector body 1, a mounting flange 2, a heat insulation pipe 3, a sealing window 4, a first pair of threads 5, a tee 6, a second pair of threads 7, a universal joint base 8, an explosion-proof junction box and a central chamber cabinet. The explosion-proof junction box and the central chamber cabinet are not shown in the figure. The mounting flange connects the lens side of the flame detector body and one end of the heat insulation pipe. The other end of the heat insulation pipe is connected to one side of the sealing window. The other side of the sealing window is connected to one end of the first pair of threads. The other end of the first pair of threads is connected to the right opening of the tee. The left opening of the tee is connected to one end of the second pair of threads. The other end of the second pair of threads is connected to the universal joint base. The explosion-proof junction box is connected to the flame detector body through a cable. The explosion-proof junction box is connected to the power signal DC 24V and the NUMER switch signal terminal of the central chamber cabinet. The lower opening of the tee is connected to the instrument air pipeline. A rotameter and a filter pressure reducing valve (not shown in the figure) are provided on the instrument air pipeline.

[0031] In this embodiment, the sealing window is made of quartz material.

[0032] In this embodiment, the cable is an armored cable, and a quick-release joint is provided at the end of the cable.

[0033] As Figure 2As shown in the figure, the flame detector body includes a flame sensor 11, a switch relay 12, a gain selector 13, two flicker frequency filters 14, a switch timer 15, a self-checking circuit 16, a timer circuit 17, a flame relay 18 and an output unit. The output unit consists of an analog signal display unit 19 and an LED bar display unit 20. Among them, the flame sensor is connected to the switch relay. The switch relay is composed of a main relay and a sub-relay. The main relay is connected to the switch timer, and the sub-relay is connected to the gain selector and is respectively connected to the two flicker frequency filters. The two flicker frequency filters are respectively connected to the analog signal display unit and the LED bar display unit.

[0034] In this embodiment, the two flicker frequency filters are also respectively connected to the self-checking circuit and the timer circuit. The timer circuit is connected to the switch timer, and the self-checking circuit is connected to the flame relay.

[0035] In this embodiment, the flame sensor is an infrared and ultraviolet composite sensor.

[0036] The working principle of the present utility model:

[0037] The flame sensor converts the optical signal of the flame into an electrical signal. The electrical signal is transmitted through the circuit. The electrical signal is distributed by the switch relay into two independent gain working units. The high gain or low gain can be selected through the gain selector. When the flame exists, the pre-set gain selector is used to amplify the flame signal, and the signal is transmitted to the two flicker frequency filters to judge the presence or absence of the flame, and the signal is further output to display the intensity of the flame. When the flame disappears, the environmental signal can be filtered through the flicker frequency filter, and the signal is evaluated through the self-checking circuit and the timer circuit to eliminate the disappearance error such as flame flicker, and the energization or de-energization of the flame relay is controlled to determine the flame detection result.

[0038] Finally, it should be noted that this embodiment is only used to illustrate the present utility model and does not limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A flame detector for a propane dehydrogenation device heating furnace, characterized in that: The flame detector for a propane dehydrogenation device heating furnace comprises a flame detector body (1), a mounting flange (2), a heat-insulating tube (3), a sealing window (4), a first pair of wires (5), a three-way tube (6), a second pair of wires (7), a universal joint base (8), an explosion-proof junction box and a central room cabinet. The flame detector body, the mounting flange, the heat-insulating tube, the sealing window, the first pair of wires, the three-way tube, the second pair of wires and the universal joint base are connected in sequence. The explosion-proof junction box is connected to the flame detector body through a cable, and the explosion-proof junction box is electrically connected to the central room cabinet.

2. The flame detector for a propane dehydrogenation device heating furnace according to claim 1, characterized in that: One end of the three-way pipe is connected to an instrument air pipeline, and a rotor flowmeter and a filter pressure reducing valve are arranged on the instrument air pipeline.

3. The flame detector for a propane dehydrogenation device heating furnace according to claim 1, characterized in that: The sealing window is made of quartz material.

4. The flame detector for a propane dehydrogenation furnace according to claim 1, characterized in that: The cable is an armored cable, and a quick-release connector is provided at the end of the cable.

5. The flame detector for a propane dehydrogenation device heating furnace according to claim 1, characterized in that: The flame detector body comprises a flame sensor (11), a switch relay (12), a gain selector (13), two flicker frequency filters (14), a switch timer (15) and an output unit, wherein the flame sensor is connected to the switch relay, the switch relay is respectively connected to the gain selector, the switch timer and the two flicker frequency filters, and the two flicker frequency filters are connected to the output unit.

6. The flame detector for a propane dehydrogenation device heating furnace according to claim 5, characterized in that: The flame detector body further comprises a self-checking circuit (16) and a timer circuit (17), the flicker frequency filter is connected to the self-checking circuit and the timer circuit respectively, and the self-checking circuit is connected to the switch timer.

7. The flame detector for a propane dehydrogenation furnace according to claim 6, characterized in that: The flame detector body also includes a flame relay (18), which is connected to the self-checking circuit.

8. The flame detector for a propane dehydrogenation device heating furnace according to claim 5, characterized in that: The output unit comprises an analog signal display unit (19) and an LED columnar display unit (20).

9. The flame detector for a propane dehydrogenation furnace according to claim 5, characterized in that: The flame sensor is an infrared and ultraviolet composite sensor.

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