Tubular flue gas cooler

Abstract

The utility model discloses a tubular flue gas cooler which comprises a flue gas inlet box, an inlet gas cooling tube bundle vertically connected to the bottom of the inlet gas box, a flue gas outlet box and an outlet gas cooling tube bundle vertically connected to the bottom of the outlet gas box, and the bottoms of the two tube bundles are communicated through an ash hopper to form a flue gas flow channel; a plurality of axial flow fans are arranged outside the flue gas flow channel, and air outlets of the axial flow fans are communicated with the outer wall space of the cooling tube bundle; a vibrating ash removal mechanism is arranged on the tube bundle; the axial flow fan and the temperature sensor group are interlocked to form a temperature adjusting assembly; and the vibration ash removal mechanism and the pressure transmitter group are interlocked to form a pressure difference response ash removal assembly. The air indirect cooling mode and the U-shaped flue gas flow channel design are adopted, forced convection heat exchange is conducted on the outer wall of the tube bundle through the variable-frequency axial flow fans, the moisture content and corrosivity of flue gas are prevented from being increased, and the cooling efficiency is improved by prolonging the residence time.

Description

Technical Field

[0001] This utility model belongs to the field of industrial high-temperature flue gas cooling technology, specifically a tubular flue gas cooler. Background Technology

[0002] In industrial sectors such as metallurgy, waste incineration, and cement production, furnaces and kilns generate large amounts of high-temperature, dust-laden flue gas during operation, with temperatures generally exceeding 130°C and sometimes reaching several hundred degrees Celsius. If this flue gas is emitted directly without treatment, it not only wastes thermal energy, but the pollutants such as dust, sulfides, and nitrogen oxides it contains also pose serious threats to the atmospheric environment and human health. Therefore, domestic and international environmental regulations strictly stipulate that industrial flue gas must undergo cooling, dust removal, desulfurization, and denitrification treatment to meet emission standards before being released into the atmosphere.

[0003] Currently, cooling processes for high-temperature flue gas are mainly divided into two categories: direct cooling and indirect cooling.

[0004] Indirect cooling technology isolates the flue gas from the heat exchange medium to avoid altering the flue gas composition. It mainly includes indirect water cooling and indirect air cooling.

[0005] Indirect water cooling uses water pipes or water jackets to absorb heat from flue gas, resulting in high cooling efficiency. However, it requires a continuous supply of large amounts of cooling water (making it difficult to promote, especially in water-scarce areas), and scale easily forms on the inner walls of the water pipes. Experiments show that when the cooling water temperature exceeds 45°C, the deposition rate of carbonate scale increases exponentially, leading to a 30%-50% decrease in the heat transfer coefficient. This necessitates frequent acid washing or pipe replacement, resulting in high maintenance costs.

[0006] Indirect air cooling uses air as the cooling medium, making it particularly suitable for water-scarce regions. Traditional solutions often employ plate heat exchangers, but their narrow flow channel design (typically only 5-10mm) makes them extremely sensitive to dusty flue gas: dust gradually accumulates in the flow channel, forming an insulation layer, causing the heat exchange efficiency to decrease rapidly over time; in severe cases, dust caking can completely block the flow channel, forcing the system to shut down for manual cleaning, affecting production continuity.

[0007] Further research indicates that existing indirect air-cooling technologies still have two major common drawbacks:

[0008] Insufficient temperature control accuracy: The flow rate and temperature of high-temperature flue gas often fluctuate with the production process (such as the feeding cycle of metallurgical furnaces and the change in the amount of feed in incinerators). Traditional coolers lack dynamic adjustment capabilities and can only perform rough temperature control by fixing the air volume or simply starting and stopping the fan, resulting in an outlet temperature fluctuation range of ±20℃, which is difficult to meet the strict requirements of precision dust removal equipment for inlet temperature.

[0009] Difficulties in dust removal and maintenance: The enclosed structure of plate heat exchangers makes it difficult to install mechanical vibration dust removal devices. When dust accumulation is severe, it is even necessary to remove part of the outer shell for manual cleaning, which increases safety hazards and prolongs downtime. In addition, key parameters (such as tube bundle differential pressure and ash hopper level) lack real-time monitoring and intelligent interlocking, often relying on manual experience to judge the timing of dust removal, which easily leads to problems of untimely or excessive dust removal.

[0010] In summary, developing an indirect air-cooled device that can adapt to high-dust conditions, achieve precise temperature control, and is easy to maintain has become a critical technological bottleneck that urgently needs to be overcome in the field of industrial flue gas treatment. This is especially true in typical scenarios such as copper smelting anode furnaces, where the dust content of the flue gas is high (up to 50g / m³). 3 The above conditions and large temperature fluctuations place higher demands on the reliability, adjustment flexibility, and ease of cleaning of the cooler. Utility Model Content

[0011] The main purpose of this utility model is to provide a tube-type flue gas cooler with automatic temperature regulation function and convenient cleaning of dust and dirt inside the heat exchange tubes.

[0012] The tubular flue gas cooler provided by this utility model includes a flue gas inlet box and an inlet cooling tube bundle vertically connected to the bottom of the inlet box, a flue gas outlet box and an outlet cooling tube bundle vertically connected to the bottom of the outlet box, and the bottoms of the two tube bundles are connected through an ash hopper to form a flue gas flow channel; multiple axial flow fans are arranged outside the flue gas flow channel, and their air outlets are connected to the space of the outer wall of the cooling tube bundle; a rapping cleaning mechanism is provided on the tube bundle; the axial flow fans are interlocked with a temperature sensor group to form a temperature regulation component; the rapping cleaning mechanism is interlocked with a pressure transmitter group to form a differential pressure response cleaning component.

[0013] In one embodiment of the above-mentioned cooler, the inlet cooling tube bundle and the outlet cooling tube bundle are composed of seamless steel tubes arranged in an alternating equilateral triangle pattern.

[0014] In one embodiment of the above-mentioned cooler, the inlet and outlet directions of the flue gas inlet box and the flue gas outlet box are arranged orthogonally; and a removable maintenance cover is provided on the top of both.

[0015] In one embodiment of the above-mentioned cooler, the temperature sensor group includes at least one inlet temperature sensor disposed at the flue gas inlet box and at least one outlet temperature sensor disposed at the flue gas outlet box.

[0016] In one embodiment of the above-mentioned cooler, the pressure transmitter group includes an inlet pressure transmitter disposed at the flue gas inlet box and an outlet pressure transmitter disposed at the flue gas outlet box.

[0017] In one embodiment of the above-mentioned cooler, the ash hopper is equipped with a hopper wall vibrator, a rotary level gauge, and a series ash discharge channel including a manual slide gate valve and a star-shaped discharge valve.

[0018] In one embodiment of the aforementioned cooler, the rapping and dust removal mechanism includes a chain-driven hammer lifting device that converts the impact force into vibration waves and transmits them to the tube bundle via a disc spring.

[0019] In one embodiment of the above-mentioned cooler, the axial flow fans are arranged in zones along the flow channel, and the speed of each zone fan is independently adjusted according to temperature fluctuations.

[0020] In one embodiment of the aforementioned cooler, a support frame is also provided, with spiral staircases arranged around the frame and guardrails installed.

[0021] In one embodiment of the above-mentioned cooler, a manhole is provided on the ash hopper.

[0022] The beneficial effects of this utility model are as follows:

[0023] 1. The system adopts an indirect air cooling method and a U-shaped flue gas flow channel design. Multiple variable frequency axial flow fans are used to force convection heat exchange on the outer wall of the tube bundle, which avoids increasing the moisture content and corrosiveness of the flue gas and improves the cooling efficiency by extending the residence time.

[0024] 2. Through the interlocking control of temperature sensor and variable frequency axial flow fan, combined with the start-stop of each fan along the U-shaped flow channel and the coordinated operation of variable frequency regulating fan, precise closed-loop control of flue gas outlet temperature can be achieved, which can dynamically adapt to complex working conditions such as flue gas volume, inlet temperature and ambient temperature fluctuations.

[0025] 3. A large-diameter heat exchange tube bundle is used in conjunction with a spring hammer rapping and dust removal device, combined with the differential pressure monitoring interlocking mechanism of the inlet / outlet pressure transmitters, to form an intelligent judgment of the degree of dust accumulation and a graded dust removal strategy. This not only ensures the daily rapping and dust removal effect, but also triggers high-frequency rapping and manual intervention prompts when the differential pressure exceeds the limit, effectively maintaining heat exchange efficiency and preventing channel blockage. Attached Figure Description

[0026] Figure 1 This is a front view structural diagram of an embodiment of the present invention.

[0027] Figure 2 for Figure 1 A side view structural diagram.

[0028] Figure 3 for Figure 1 A top-view structural diagram.

[0029] Figure 4 for Figure 3Schematic diagram of the cross-sectional structure of the inlet cooling tube bundle and the outlet cooling tube bundle.

[0030] Figure label:

[0031] 1. Flue gas inlet box, 11. Inlet temperature sensor, 12. Inlet pressure transmitter, 2. Flue gas outlet box, 21. Outlet temperature sensor, 22. Outlet pressure transmitter, 3. Inlet cooling tube bundle, 4. Outlet cooling tube bundle, 5. Ash hopper, 51. Bin wall vibrator, 52. Rotary paddle level gauge, 53. Manual slide gate valve, 54. Rotary rotary valve, 55. Manhole door, 6. Frame, 7. Axial flow fan, 8. Vibrating dust removal device. Detailed Implementation

[0032] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments, and not all of the embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model.

[0033] like Figures 1 to 3 As shown, the tubular flue gas cooler disclosed in this embodiment includes a flue gas inlet box 1, a flue gas outlet box 2, an inlet cooling tube bundle 3, an outlet cooling tube bundle 4, an ash hopper 5, a frame 6, an axial flow fan 7, and a rapping cleaning device 8.

[0034] The flue gas inlet box 1 and flue gas outlet box 2 are located on the upper part of the cooler, and adopt a box-type structure with a removable maintenance cover on the top. The inlet box is connected to the external high-temperature flue gas pipeline through the upper flue gas inlet, and the outlet box is connected to the subsequent dust collection equipment through the upper flue gas outlet.

[0035] In this embodiment, the flue gas inlet box and flue gas outlet box are equipped with maintenance covers to facilitate the thorough removal of accumulated ash and dirt inside the tube bundle during maintenance, thereby improving heat exchange efficiency.

[0036] In this embodiment, the inlet and outlet directions of the flue gas inlet box 1 and the flue gas outlet box 2 are arranged at 90°. The flue gas inlet and outlet directions can be determined according to the specific pipe connection direction.

[0037] The inlet cooling tube bundle 3 is vertically connected to the bottom of the flue gas inlet box 1, and the outlet cooling tube bundle 4 is vertically connected to the bottom of the flue gas outlet box 2; the bottom of both tube bundles is connected to the ash hopper 5.

[0038] The ash hopper 5 has a conical structure, and the two tube bundles are connected at the bottom of the ash hopper through a folding structure.

[0039] The flue gas flow path of this cooler is as follows:

[0040] High-temperature flue gas enters from the top of the flue gas inlet box 1, flows downward through the inlet cooling tube bundle 3 to the bottom of the ash hopper 5, turns back and flows upward through the outlet cooling tube bundle 4 into the flue gas outlet box 2, and finally exits from the top, forming a U-shaped flow path.

[0041] like Figure 4 As shown, in this embodiment, the inlet cooling tube bundle 3 and the outlet cooling tube bundle 4 are made of φ168×5.5 seamless steel pipes, arranged in an alternating equilateral triangle pattern with a tube center distance of 252mm. The inlet cooling tube bundle is divided into 12 rows, with 6 tubes per row, for a total of 72 tubes. The outlet cooling tube bundle is also divided into 12 rows, with 6 rows of 6 tubes and 6 rows of 5 tubes, for a total of 66 tubes. Tube bundles A and B together have a total of 138 tubes. The specifications, length, and arrangement of the tube bundles can be designed according to the flue gas volume, flue gas temperature, and other conditions of the specific project.

[0042] The frame 6 includes I-beam columns and a No. 16 channel steel frame, which support the aforementioned components such as flue gas inlet box 1, flue gas outlet box 2, inlet cooling tube bundle 3, outlet cooling tube bundle 4, and ash hopper 5.

[0043] The framework 6 is surrounded by spiral staircases. The staircase railings consist of Φ40 handrails, Φ40 vertical bars, and Φ30 horizontal bars, with a height of 1.1m, meeting the requirements for maintenance access.

[0044] Six variable frequency axial flow fans 7 are arranged along the U-shaped flue gas flow channel. The axial flow fans are fixed to the outside of the inlet cooling tube bundle 3 and the outlet cooling tube bundle 4 by the frame 6. The air outlet of the fan is connected to the space of the outer wall of the cooling tube bundle, and indirect air cooling heat exchange is carried out through the tube wall.

[0045] Two spring hammer oscillating dust removal devices 8 are installed at the middle of the height direction of the inlet cooling tube bundle 3 and the outlet cooling tube bundle 4.

[0046] The rapping and dust removal device 8 includes a motor, a worm gear reducer, a drive sprocket, a chain, a hammer lifting device, and a spring rapping rod.

[0047] The electric motor drives the drive sprocket via a worm gear reducer, which in turn drives the hammer-lifting device via a chain. The hammer is raised to a set height, and then, under the action of the drop hammer device, it falls, striking the spring-loaded vibrating rod. The hammer-lifting mechanism continues to rotate with the driven wheel, is guided back to its original position by the spring, and then lifts the hammer again for a second strike, thus repeating the cycle continuously. The spring-loaded vibrating rod is equipped with a pair of disc springs, which cause the vibration force to form a specific frequency that is transmitted to the dust-accumulated cooling tube bundle, thereby shaking off the accumulated dust.

[0048] The rapping and dust removal device in this embodiment uses a spring hammer rapping and dust removal device. Alternatively, a pneumatic rapping device, a cantilever hammer rapping device, or other dust removal methods can be used depending on the specific circumstances.

[0049] The cooler not only has the function of cooling flue gas, but also can collect dust to a certain extent during the flue gas flow. Therefore, an ash hopper 5 is set at the bottom for ash storage.

[0050] One bin wall vibrator 51 is installed on each of the two adjacent sides of the ash hopper 5, and a rotary level gauge 52 is installed on the other side. A manual slide valve 53 and a star-shaped discharge valve 54 are connected in sequence to the bottom of the ash hopper to form a two-stage ash discharge channel.

[0051] The rotary paddle level gauge 52 is used to monitor the material level in the ash hopper. Once a signal is received, it will issue a "high material level" alarm to remind the operator to unload the ash in time to avoid blocking the flue gas passage.

[0052] The rotary valve 54 and the bin vibrator 51 are manually controlled, with a single knob controlling both start and stop. Manual operation: Press and hold the start button on the bin vibrator to start it. Release the button to turn it off.

[0053] A manhole 55 is provided on the ash hopper 5 for observation and maintenance of ash accumulation and blockage.

[0054] The flue gas inlet box 1 is equipped with an inlet temperature sensor 11 and an inlet pressure transmitter 12; the flue gas outlet box 2 is equipped with an outlet temperature sensor 21 and an outlet pressure transmitter 22; these are used to monitor temperature and pressure.

[0055] Temperature monitoring is used to meet cooling requirements; the temperature sensor is interlocked with the variable frequency axial flow fan. When the flue gas volume, flue gas temperature and external ambient temperature fluctuate, causing changes in heat exchange capacity, the required air volume for cooling is adjusted by starting and stopping the axial flow fan one by one and then adjusting the outlet temperature of the cooler to the required temperature range.

[0056] Monitoring the inlet and outlet pressures is used to determine whether the inlet and outlet cooling tube bundles are severely dusty, thereby increasing the dust removal frequency. The pressure transmitter is interlocked with the rapping dust removal device; the degree of internal dust accumulation is monitored by pressure comparison, and when the pressure difference reaches a certain threshold, the rapping frequency is increased, and a reminder is given to address the dust accumulation problem.

[0057] Three outlet temperature sensors 21 and three inlet temperature sensors 11 are provided so that the system can continue to operate even if one of them is damaged or malfunctions.

[0058] A platform is provided on hopper 5 for maintaining the hopper wall vibrator, the rotary level gauge, and the manhole.

[0059] The axial flow fan 3, the rapping dust removal device 4, the top flue gas inlet box 1, the flue gas outlet box 2, the top inspection door, and the inlet and outlet connection are all equipped with platforms to facilitate maintenance.

[0060] All platforms are made of 4mm patterned steel plate.

[0061] The modules are connected by flange bolts, and the ash hopper and the tube bundle are sealed by welding.

[0062] This tubular flue gas cooler uses indirect air-cooled heat exchange through a U-shaped flue gas flow channel. Its specific working principle is as follows:

[0063] High-temperature, dust-laden flue gas enters from the top of the flue gas inlet box, flows downward through the inlet cooling tube bundle to the bottom of the ash hopper, then turns back upward through the outlet cooling tube bundle into the flue gas outlet box, and finally exits from the top, forming a U-shaped flow path. Cooling air is blown into the external space of the cooling tube bundle by multiple variable frequency axial flow fans, where it comes into contact with the tube wall for indirect heat exchange. The heat from the flue gas is transferred to the air medium through the tube wall, achieving cooling.

[0064] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A shell-and-tube flue gas cooler, characterized by: It comprises a flue gas inlet tank, a flue gas inlet cooling pipe bundle vertically connected to the bottom of the inlet tank, a flue gas outlet tank, a flue gas outlet cooling pipe bundle vertically connected to the bottom of the outlet tank, and a flue gas flow channel formed by the two pipe bundles through a hopper; A plurality of axial flow fans are arranged outside the flue gas flow channel, the air outlets of which are in space communication with the outer wall of the cooling pipe bundle; a rapping and ash removal mechanism is arranged on the pipe bundle; the axial flow fan and the temperature sensor group are interlocked to form a temperature regulating assembly; the rapping and ash removal mechanism and the pressure transmitter group are interlocked to form a differential pressure response ash removal assembly.

2. The tubular flue gas cooler according to claim 1, characterized in that: The inlet and outlet cooling pipe bundles are composed of seamless steel pipes arranged in a regular triangle.

3. The tubular flue gas cooler according to claim 1, characterized in that: The inlet and outlet of the flue gas inlet tank and the flue gas outlet tank are arranged in a normal direction; removable maintenance cover plates are arranged on the top of the two tanks.

4. The tubular flue gas cooler according to claim 1, characterized in that: The temperature sensor group comprises at least one inlet temperature sensor arranged at the inlet of the flue gas inlet tank and at least one outlet temperature sensor arranged at the outlet of the flue gas outlet tank.

5. The tubular flue gas cooler according to claim 1, characterized in that: The pressure transmitter group comprises an inlet pressure transmitter arranged at the inlet of the flue gas inlet tank and an outlet pressure transmitter arranged at the outlet of the flue gas outlet tank.

6. The tubular flue gas cooler according to claim 1, characterized in that: The hopper is provided with a bin wall vibrator, a material level meter, and a series ash discharge channel comprising a manual gate valve and a star-shaped discharge valve.

7. The tubular flue gas cooler according to claim 1, characterized in that: The rapping and ash removal mechanism comprises a chain-driven hammer lifting device, which converts impact force into vibration waves through a disc spring and transmits the vibration waves to the pipe bundle.

8. The tubular flue gas cooler according to claim 1, characterized in that: The axial flow fans are arranged in different regions along the flow channel, and the rotational speed of each fan is independently adjusted according to temperature fluctuation.

9. The tubular flue gas cooler according to claim 1, characterized in that: A support frame is further provided, and spiral stairs are arranged around the frame and provided with protective railings.

10. The tubular flue gas cooler according to claim 1, characterized in that: A manhole door is arranged on the hopper.

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