Spiral finned tube heat exchanger

Abstract

The invention discloses a spiral finned tube heat exchanger, and relates to the field of heat exchanger application, the spiral finned tube heat exchanger comprises a box body, a heat exchanger assembly is arranged in the box body, the heat exchanger assembly comprises a plurality of groups of heat exchange tubes which are distributed in a staggered manner, each heat exchange tube comprises a base tube and an outer spiral fin, and an inner spiral fin is arranged in the base tube; and ash removal assemblies are arranged above the multiple sets of heat exchange pipes of the heat exchanger assembly, and the ash removal assemblies are driven by water flow in the water tank. The inner spiral fins are arranged in the base tube, the spiral distribution tracks of the outer spiral fins and the spiral distribution tracks of the inner spiral fins are also the same, and therefore the distance between the fin roots of the outer spiral fins and the outer edges of the inner spiral fins on a heat transfer path is the shortest; heat can be transferred to the inner spiral fins through the shortest heat transfer path, the contact area of the inner spiral fins and the cold medium is larger, and therefore the heat transfer efficiency between smoke and the cold medium can be improved.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger applications, specifically a spiral finned tube heat exchanger. Background Technology

[0002] Flue gas heat exchangers (also known as waste heat exchangers) are core energy-saving devices that recover waste heat from flue gas emitted by industrial equipment. Essentially, they transfer waste heat from the flue gas to a cold medium (such as water, air, or heat transfer oil) through "heat transfer," enabling the reuse of waste heat (such as heating water, preheating combustion air, or generating steam). Ultimately, this improves energy efficiency, reduces flue gas temperature, and decreases pollutant emissions, making it one of the key devices for industrial energy conservation and green production.

[0003] Spiral finned tube heat exchangers are a common type of heat exchanger. Their core feature is that spiral fins are wound, welded, or rolled on the outer surface of the base tube (usually a round tube). This increases the heat transfer area and enhances fluid turbulence to improve heat exchange efficiency. Multiple spiral finned heat exchange tubes are arranged in an alternating pattern. The cold water that needs to be heated flows through the spiral finned heat exchange tubes. High-temperature flue gas is propelled through multiple sets of spiral finned heat exchange tubes by a fan, thereby transferring the heat in the flue gas to the cold water and raising its temperature.

[0004] In practical applications, flue gas heat exchangers typically use multiple sets of spiral finned heat exchange tubes arranged horizontally. Flue gas contains a significant amount of dust, and even after preliminary sieving and filtration, it still contains fine dust particles. Consequently, when the flue gas comes into contact with the heat exchange tubes for heat exchange, the dust accumulates between the spiral fins, especially in the upper fin gaps of the spiral finned heat exchange tubes (for the lower fin gaps, due to gravity, the dust tends to fall naturally into the fin gaps above the lower set of spiral finned heat exchange tubes). The high resistance caused by dust accumulation on the heat exchange tube surface significantly reduces heat transfer efficiency. Therefore, regular dust cleaning is crucial for ensuring the heat exchanger's operating efficiency. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a spiral finned tube heat exchanger to solve the technical problems mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a spiral finned tube heat exchanger, comprising a housing, wherein a heat exchanger assembly is disposed inside the housing, the heat exchanger assembly comprising multiple sets of staggered heat exchange tubes, each heat exchange tube comprising a base tube, one end of which is provided with an inlet and the other end with an outlet, the base tube being provided with external spiral fins, and the interior of the base tube having spiral fitting grooves matching the external spiral fins, the end of the base tube being threadedly connected to a cap, the side of which is connected to an inner spiral fin, the inner edge of which is toothed, the inner spiral fins and... The heat exchanger assembly is installed with spiral interlocking grooves. The inlets of two adjacent sets of heat exchanger tubes are connected to each other, and the outlets of two adjacent sets of heat exchanger tubes are connected to each other by setting bends. The inlet of one set of heat exchanger tubes in the heat exchanger assembly is connected to a main inlet pipe, which is connected to a water supply device. The outlet of one set of heat exchanger tubes in the heat exchanger assembly is connected to a main outlet pipe, which is connected to a water tank. The water tank is connected to a water supply device. A dust removal assembly is installed above each set of heat exchanger tubes in the heat exchanger assembly. The dust removal assembly is driven by the water flow inside the water tank.

[0007] By adopting the above technical solution, the inner spiral fins are movably installed by opening a spiral interlocking groove on the inner side of the base tube. The spiral interlocking groove and the outer spiral fins have the same spiral distribution trajectory, and thus the spiral distribution trajectories of the outer spiral fins and the inner spiral fins are also the same. Therefore, the distance between the fin root of the outer spiral fin and the outer edge of the inner spiral fin is the shortest in the heat transfer path. When the high-temperature flue gas transfers heat to the outer spiral fins, the heat can be transferred to the inner spiral fins through the shortest heat transfer path. The inner spiral fins have a larger contact area with the cold medium, thereby improving the heat transfer efficiency between the flue gas and the cold medium. The inner side of the inner spiral fins is toothed, and the toothed structure can turbulent the cold medium, causing it to generate more eddies, thereby allowing the cold medium to better exchange heat with the inner wall of the base tube and the inner spiral fins.

[0008] The present invention is further configured such that the water tank includes a shell, the interior of the shell is provided with multiple sets of baffles to form an S-shaped waterway, and the bottom of the shell is provided with a drain pipe, which is connected to a water-using device.

[0009] Preferably, by setting up a larger S-shaped water channel, the water level entering the water tank is lowered, meaning that the water level entering the water tank only covers the lower half of the drive impeller. The water flows in the S-shaped water channel to drive the drive impeller to rotate, thereby driving multiple sets of dust removal components to rotate, reducing the accumulation of dust on the top of the heat exchange tubes.

[0010] The present invention is further configured such that one end of the S-shaped waterway is connected to the main outlet pipe and the other end is connected to the drainage pipe, and the diameter of the S-shaped waterway is larger than that of the main outlet pipe.

[0011] Preferably, by setting up an S-shaped waterway, the water entering the water tank can flow in an S-shaped path to drive each set of impellers, thereby driving multiple sets of dust removal components to rotate.

[0012] The present invention is further configured such that the dust removal assembly includes a transmission rod, the transmission rod is rotatably connected to the outer wall of the housing, and the transmission rod extends into the interior of the housing. Multiple sets of dust removal rollers are provided on the outside of the transmission rod, and the multiple sets of dust removal rollers are distributed in the gaps of the outer spiral fins. A drive impeller is provided at one end of the transmission rod located inside the housing.

[0013] Preferably, by installing a dust removal component above the heat exchange tube, the dynamic rotation of the dust removal component can reduce the accumulation of dust in the gaps of the outer spiral fins.

[0014] The invention is further configured such that an opening groove is provided at the top of the outer helical fin, and the opening groove is used to fit the transmission rod.

[0015] Preferably, by opening a slot at the top of the outer spiral fins for installing the transmission rod, the transmission rod can be closer to the outer wall of the base tube, and the cleaning wheel outside the transmission rod can also be closer to the outer wall of the base tube, achieving deep cleaning of the gap between the outer spiral fins. The outer spiral fins are made by spirally winding metal steel strips around the outer wall of the base tube and simultaneously using high-frequency welding. Multiple slots are stamped out of the metal steel strips at equal intervals. Therefore, when the metal steel strips are spirally welded to the outside of the base tube, the multiple slots are distributed along the same axis.

[0016] The present invention is further configured such that the heat exchanger assembly is provided in multiple sets, and the inlet of one set of heat exchanger tubes of the multiple sets of heat exchanger assemblies is connected to the main water inlet pipe.

[0017] Preferably, multiple heat exchanger assemblies are connected in parallel to fully exchange heat with the high-temperature flue gas, thereby improving the working efficiency of the heat exchange equipment.

[0018] The present invention is further configured such that the outlet of one set of heat exchange tubes in the plurality of heat exchanger assemblies is connected to the main outlet pipe.

[0019] Preferably, by connecting multiple heat exchanger assemblies to the same set of inlet and outlet water pipes, the water supply device can supply water to multiple heat exchanger assemblies simultaneously, and the water from multiple heat exchanger assemblies is centrally discharged into the water tank through the outlet water pipe.

[0020] The invention is further configured such that a dust removal door is provided at the bottom of the box for periodically cleaning the dust accumulated inside the box.

[0021] Preferably, a dust removal hatch is installed at the bottom of the enclosure for staff to regularly clean and maintain the heat exchange equipment.

[0022] In summary, the present invention has the following main beneficial effects: This invention involves installing inner spiral fins by creating a spiral interlocking groove on the inner side of the base tube. The spiral interlocking groove and the outer spiral fins have the same spiral distribution trajectory, which in turn makes the spiral distribution trajectories of the outer and inner spiral fins identical. Therefore, the distance between the root of the outer spiral fin and the outer edge of the inner spiral fin is the shortest in the heat transfer path. When high-temperature flue gas transfers heat to the outer spiral fins, the heat can be transferred to the inner spiral fins through the shortest heat transfer path. The inner spiral fins have a larger contact area with the cold medium, thereby improving the heat transfer efficiency between the flue gas and the cold medium. The inner side of the inner spiral fins is toothed, and the toothed structure can turbulentize the cold medium, causing it to generate more eddies, thus allowing the cold medium to better exchange heat with the inner wall of the base tube and the inner spiral fins.

[0023] This invention utilizes rotating dust removal components positioned above each set of heat exchange tubes. The continuous rotation of these components reduces dust accumulation in the gaps between the fins above the heat exchange tubes. Multiple dust removal components extend into a water tank, which serves as a transfer station for the cooling medium. The S-shaped water channels within the tank provide greater flow space, causing the liquid level of the cooling medium flowing from the main outlet pipe to decrease upon entering the tank. The cooling medium flows sequentially through the lower half of the drive impeller of each dust removal component, thereby using the flow of the cooling medium to drive the entire dust removal component to rotate slowly. This dynamic dust removal system reduces the active accumulation of dust in the flue gas, ensuring efficient heat exchange between the flue gas and the heat exchange tubes. Furthermore, the rotation of the dust removal components induces eddies in the flue gas, further improving the heat exchange efficiency between the flue gas and the heat exchange tubes. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the heat exchanger assembly structure of the present invention; Figure 3 This is a schematic diagram of the heat exchange tube structure of the present invention; Figure 4 This is a schematic diagram of the spiral interlocking groove distribution of the present invention; Figure 5 This is a schematic diagram of the internal helical fin structure of the present invention; Figure 6 This is a schematic diagram showing the distribution of the inlet and outlet water mains of the present invention; Figure 7 This is a schematic diagram showing the distribution of the heat exchange tubes and the dust removal assembly of the present invention; Figure 8 This is a schematic diagram of the internal structure of the water tank of the present invention; Figure 9 This is a plan view showing the distribution of the outer helical fins, the base tube, and the inner helical fins of the present invention. Figure 10This is a schematic diagram showing the distribution of the outer and inner helical fins of the present invention.

[0025] Explanation of reference numerals in the attached figures: 1. Housing; 2. Heat exchanger assembly; 3. Heat exchange tube; 301. Base tube; 302. Inlet; 303. Outlet; 304. Outer spiral fins; 305. Opening groove; 306. Spiral fitting groove; 307. Plug; 308. Inner spiral fins; 4. Bend; 5. Inlet main pipe; 6. Outlet main pipe; 7. Water tank; 701. Shell; 702. Baffle; 703. S-shaped water channel; 704. Drainage pipe; 8. Dust removal assembly; 801. Drive rod; 802. Dust removal impeller; 803. Drive impeller. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] The embodiments of the present invention will now be described.

[0028] Please see Figures 1-10 A spiral finned tube heat exchanger includes a housing 1. A heat exchanger assembly 2 is housed inside the housing 1. The heat exchanger assembly 2 includes multiple sets of staggered heat exchange tubes 3. Each heat exchange tube 3 includes a base tube 301. One end of the base tube 301 has an inlet 302, and the other end has an outlet 303. External spiral fins 304 are provided on the outside of the base tube 301. A spiral fitting groove 306 matching the external spiral fins 304 is formed inside the base tube 301. A plug 307 is threadedly connected to the end of the base tube 301. The side of the plug 307 is connected to an inner spiral fin 308. The inner edge of the inner spiral fin 308 is toothed. The inner spiral fin 308 is made of metal steel strip spirally bent, and multiple tooth grooves are punched out of the metal steel strip at equal intervals. The inner spiral fin 308 and the spiral fitting groove 306 are fitted together and installed. Thus, the inner spiral fin 308 can be spirally removed from the inside of the base tube 301. When solidified scale accumulates inside the base tube 301, removing the inner spiral fin 308 can break up the scale and remove some of the scale. In the heat exchanger assembly 2, the inlets 302 of two adjacent sets of heat exchange tubes 3 are connected to each other. The inlets 302 are movable joints, and the outlets 303 of two adjacent sets of heat exchange tubes 3 are connected to each other by setting up bends 4. The bends 4 and outlets 303 are processed by welding. The inlet 302 of one set of heat exchange tubes 3 in the heat exchanger assembly 2 is connected to a main water inlet pipe 5. The main water inlet pipe 5 is connected to a water supply device, which includes a water supply pipe, a water source, a control system, and a water pump. The outlet 303 of one set of heat exchange tubes 3 in the heat exchanger assembly 2 is connected to a main water outlet pipe 6. The main water outlet pipe 6 is connected to a water tank 7. The water tank 7 is connected to a water-using device, such as water for industrial equipment or water for washing in factory dormitories. A dust removal assembly 8 is installed above each set of heat exchange tubes 3 in the heat exchanger assembly 2. The dust removal assembly 8 is driven by the water flow inside the water tank 7.

[0029] Please refer to the above embodiments for further details. Figure 8 The water tank 7 includes a shell 701. The interior of the shell 701 is formed by multiple sets of baffles 702 to form an S-shaped water channel 703. The bottom of the shell 701 is provided with a drain pipe 704, which is connected to the water-using device. By setting up a larger S-shaped water channel 703, the water level entering the water tank 7 is lowered, that is, the water level entering the water tank 7 only covers the lower half of the drive impeller 803. The water flows in the S-shaped water channel 703 to drive the drive impeller 803 to rotate, thereby driving multiple sets of dust removal components 8 to rotate, reducing the accumulation of dust on the top of the heat exchange tube 3.

[0030] Please refer to the above embodiments for further details. Figure 8 One end of the S-shaped water channel 703 is connected to the main water outlet pipe 6, and the other end is connected to the drainage pipe 704. The diameter of the S-shaped water channel 703 is larger than that of the main water outlet pipe 6. By setting the S-shaped water channel 703, the water entering the water tank 7 can flow in an S-shaped path to drive each set of impellers 803, thereby driving multiple sets of dust removal components 8 to rotate.

[0031] Please refer to the above embodiments for further details. Figure 7 The dust removal assembly 8 includes a transmission rod 801, which is rotatably connected to the outer wall of the housing 1 and extends into the interior of the housing 701. Multiple sets of dust removal rollers 802 are provided on the outside of the transmission rod 801 and are distributed in the gaps of the outer spiral fins 304. A drive impeller 803 is provided at one end of the transmission rod 801 inside the housing 701. By setting the dust removal assembly 8 above the heat exchange tube 3 and utilizing the dynamic rotation of the dust removal assembly 8, the accumulation of dust in the gaps of the outer spiral fins 304 can be reduced.

[0032] Please refer to the above embodiments for further details. Figure 3 and Figure 7The top of the outer spiral fin 304 is provided with an opening groove 305 for fitting the transmission rod 801. By opening the opening groove 305 on the top of the outer spiral fin 304 to install the transmission rod 801, the transmission rod 801 can be closer to the outer wall of the base tube 301. Consequently, the cleaning wheel 802 outside the transmission rod 801 can also be closer to the outer wall of the base tube 301, achieving deep cleaning of the gap between the outer spiral fins 304. The outer spiral fin 304 is made by spirally winding a metal steel strip around the outer wall of the base tube 301 and simultaneously using high-frequency welding. Multiple opening grooves 305 are stamped out of the metal steel strip at equal intervals. Therefore, when the metal steel strip is spirally welded to the outside of the base tube 301, the multiple opening grooves 305 are distributed along the same axis.

[0033] Please refer to the above embodiments for further details. Figure 6 The heat exchanger assembly 2 is provided with multiple sets. The inlet 302 of one of the heat exchange tubes 3 of the multiple sets of heat exchanger assemblies 2 is connected to the main water inlet pipe 5. The multiple sets of heat exchanger assemblies 2 are used in parallel, which can fully exchange heat with high-temperature flue gas, thereby improving the working efficiency of the heat exchange equipment.

[0034] Please refer to the above embodiments for further details. Figure 6 The outlet 303 of one of the heat exchange tubes 3 of the multiple heat exchanger assemblies 2 is connected to the main outlet pipe 6. By connecting the multiple heat exchanger assemblies 2 to the same main inlet pipe 5 and main outlet pipe 6, the water supply device can supply water to the multiple heat exchanger assemblies 2 at the same time, and the water from the multiple heat exchanger assemblies 2 is discharged into the water tank 7 through the main outlet pipe 6.

[0035] In the above embodiments, please refer to the specific examples. Figure 1 The bottom of the housing 1 is equipped with a dust removal door for regularly cleaning the dust accumulated inside the housing 1. By setting the dust removal door at the bottom of the housing 1, the heat exchange equipment can be regularly cleaned and maintained by the staff.

[0036] In practical operation, the high-temperature flue gas enters the interior of the housing 1 through the exhaust pipe under the action of the fan. The water supply device pushes water from the main water inlet pipe 5 into the interior of each heat exchanger assembly 2. Cold water enters one of the heat exchanger tubes 3 of the heat exchanger assembly 2 and flows continuously through multiple heat exchanger tubes 3 via the bend pipe 4. Finally, the cold water undergoes heat exchange and is discharged into the water tank 7 through the main water outlet pipe 6.

[0037] When the high-temperature flue gas enters the interior of the housing 1, it exchanges heat with multiple sets of heat exchange tubes 3, transferring the heat from the flue gas to the outer spiral fins 304 and the base tube 301. The heat from the outer spiral fins 304 and the base tube 301 is then transferred to the cold water. Furthermore, the heat from the outer spiral fins 304 is transferred to the inner spiral fins 308 via the shortest possible heat transfer path. The inner spiral fins 308 and the spiral fitting groove 306 are spirally fitted together. In other words, the spiral fitting groove 306 allows the inner spiral fins 308 and... The inner wall of the base tube 301 makes better contact and fit, reducing installation gaps. The more gaps there are, the lower the heat conduction efficiency. The medium flowing inside the base tube 301 can fill the installation gaps, allowing the outer spiral fins 304 and the base tube 301 to exchange heat with the inner spiral fins 308 more efficiently. The inner edge of the inner spiral fins 308 extends to the center of the cold water, and the inner edge of the inner spiral fins 308 is toothed to increase the vortex of the cold water. In other words, the inner spiral fins 308 can exchange heat with the cold water better.

[0038] Multiple sets of heat exchange tubes 3 exchange heat to raise the temperature of the cold water, which is then discharged from the main outlet pipe 6 into the water tank 7, and finally discharged from the drain pipe 704 of the water tank 7 to the water-using device. Because the S-shaped water channel 703 of the water tank 7 has a larger space, when the water enters the water tank 7, the liquid level only covers the lower half of the drive impeller 803. This utilizes hydrodynamics to drive the drive impeller 803 to rotate, which in turn drives the connected transmission rod 801 to rotate. The transmission rod 801 then drives multiple sets of drive impellers 803 to rotate, and the multiple sets of heat exchange tubes 3 and the high-temperature... When the flue gas undergoes heat exchange, dust in the flue gas will accumulate in the gap between the fins above the heat exchange tube 3. In other words, dust tends to accumulate at the locations of multiple drive impellers 803. The dynamic drive impellers 803 can reduce dust accumulation by rotating, and the dynamic drive impellers 803 can increase the vortex of the flue gas, allowing the flue gas to exchange heat with the heat exchange tube 3 better. During daily operation of the heat exchange equipment, the dust cleaned by the dust removal component 8 accumulates at the bottom of the housing 1. The staff can clean it periodically by opening the ash compartment door at the bottom of the housing 1.

[0039] When the staff needs to clean the scale on the heat exchange tubes 3, the heat exchange equipment needs to be temporarily shut down and the valve of the main outlet pipe 6 needs to be closed. Since the multiple sets of heat exchange tubes 3 of the heat exchanger assembly 2 are welded together by multiple sets of bends 4, the plug 307 of the heat exchange tubes 3 can be opened and the inner spiral fins 308 connected to the plug 307 can be unscrewed. When the inner spiral fins 308 rotate out of the base tube 301, the solidified scale can be scraped off. Then, water can be used to rinse the inside of the base tube 301 of each set of heat exchange tubes 3 from the main inlet pipe 5.

[0040] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the invention, but such modifications, substitutions, and variations are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A spiral finned tube heat exchanger, comprising a housing (1), characterized in that: The housing (1) is equipped with a heat exchanger assembly (2). The heat exchanger assembly (2) includes multiple sets of staggered heat exchange tubes (3). Each heat exchange tube (3) includes a base tube (301). One end of the base tube (301) is provided with an inlet (302), and the other end is provided with an outlet (303). The base tube (301) is provided with an outer spiral fin (304). The base tube (301) is provided with a spiral fitting groove (306) that matches the outer spiral fin (304). The end of the base tube (301) is threadedly connected to a plug (307). The side of the plug (307) is connected to an inner spiral fin (308). The inner edge of the inner spiral fin (308) is toothed. The inner spiral fin (308) and the spiral fitting groove (306) are fitted together. In the heat exchanger assembly (2), the inlets (302) of two adjacent heat exchanger tubes (3) are connected to each other, and the outlets (303) of two adjacent heat exchanger tubes (3) are connected to each other by setting up a bend (4). The inlet (302) of one heat exchanger tube (3) of the heat exchanger assembly (2) is connected to a main water inlet pipe (5), the main water inlet pipe (5) is connected to a water supply device, and the outlet (303) of one heat exchanger tube (3) of the heat exchanger assembly (2) is connected to a main water outlet pipe (6), the main water outlet pipe (6) is connected to a water tank (7), the water tank (7) is connected to a water supply device. A dust removal assembly (8) is set above each of the multiple heat exchanger tubes (3) of the heat exchanger assembly (2), and the dust removal assembly (8) is driven by the water flow inside the water tank (7).

2. The spiral finned tube heat exchanger according to claim 1, characterized in that: The water tank (7) includes a shell (701), and an S-shaped waterway (703) is formed inside the shell (701) by setting multiple sets of baffles (702). A drain pipe (704) is provided at the bottom of the shell (701), and the drain pipe (704) is connected to the water-using device.

3. A spiral finned tube heat exchanger according to claim 2, characterized in that: One end of the S-shaped waterway (703) is connected to the main outlet pipe (6), and the other end is connected to the drainage pipe (704), and the diameter of the S-shaped waterway (703) is larger than that of the main outlet pipe (6).

4. A spiral finned tube heat exchanger according to claim 3, characterized in that: The dust removal assembly (8) includes a transmission rod (801), which is rotatably connected to the outer wall of the housing (1). The transmission rod (801) extends into the interior of the housing (701). Multiple sets of dust removal wheels (802) are provided on the outside of the transmission rod (801). The multiple sets of dust removal wheels (802) are distributed in the gaps of the outer spiral fins (304). A drive impeller (803) is provided at one end of the transmission rod (801) inside the housing (701).

5. A spiral finned tube heat exchanger according to claim 4, characterized in that: The top of the outer spiral fin (304) is provided with an opening groove (305), which is used to fit the transmission rod (801).

6. A spiral finned tube heat exchanger according to claim 5, characterized in that: The heat exchanger assembly (2) is provided with multiple sets, and the inlet (302) of one set of heat exchanger tubes (3) of the multiple sets of heat exchanger assemblies (2) is connected to the main water inlet pipe (5).

7. A spiral finned tube heat exchanger according to claim 6, characterized in that: The outlet (303) of one of the heat exchange tubes (3) of the multiple heat exchanger assemblies (2) is connected to the main outlet pipe (6).

8. A spiral finned tube heat exchanger according to claim 7, characterized in that: The bottom of the box (1) is provided with a dust removal door for regularly cleaning the dust accumulated inside the box (1).

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