Steam waste heat recovery and cyclic utilization device for periodic blowdown flash tank

Abstract

The invention discloses a steam waste heat recovery and cyclic utilization device for a periodic blowdown flash tank, and relates to the technical field of heat recovery, the steam waste heat recovery and cyclic utilization device comprises a tank body, the tank body is internally provided with a steam absorption assembly and a heat exchange assembly used for absorbing heat of high-temperature waste hot water and secondary steam; the heat exchange assembly comprises a mounting box, a plurality of horizontally-arranged heat exchange pipes are rotationally arranged in the mounting box, a plurality of buffer plate sets corresponding to the heat exchange pipes are arranged in the mounting box, and belt transmission mechanisms are arranged among the heat exchange pipes. According to the heat exchanger, the rotatable heat exchange pipes are arranged, scale removing scraping strips on the first flow guide plate are matched to automatically remove scale generated in the heat exchange process, and the problem that the heat exchange efficiency is reduced due to scale accumulation is effectively solved; and soft water formed after the bottom surface of the heat exchange pipe and secondary steam are subjected to heat exchange and condensation is collected into the liquid collecting tank, so that secondary utilization of water resources is realized.

Description

Technical Field

[0001] The invention relates to the technical field of heat recovery, and in particular to a device for recovering and recycling waste heat of steam from a fixed-discharge expansion vessel. Background Art

[0002] As the world's energy becomes increasingly tight, saving energy and reducing corporate costs have become the most urgent tasks for all companies. A large number of industrial boilers and power station boilers in enterprises are equipped with deaerators and boiler fixed-discharge expansion tanks and drain expansion tanks equipped with steam-water systems during operation, which produce a large amount of high-temperature wastewater and waste gas to be discharged. The fixed-discharge wastewater contains a large amount of calorific value. It was originally directly discharged into the atmosphere and ditches after expansion and pressure reduction by the expansion tank, which not only causes thermal pollution and water pollution, but also wastes energy. Therefore, some expansion tanks that can recover waste heat have appeared. By installing coils in the expansion tank and passing desalted water inside, the desalted water is heated to recover waste heat.

[0003] After searching, the patent with the authorization announcement number CN107448925B discloses a fixed row expansion tank, including a frame and a shell fixedly installed above the frame, an exhaust port and a liquid discharge port are respectively provided at the upper and lower ends of the shell, a heat exchange tube is provided in the shell, a desalted water source is provided at one end of the heat exchange tube, a wastewater inlet pipe is provided at the lower end of the shell, a booster pump for increasing water pressure is connected to one side of the wastewater inlet pipe, a spray net pipe distributed in a mesh is provided above the wastewater inlet pipe, the upper end of the wastewater inlet pipe is expanded and connected to the lower end face of the spray net pipe, and a spray hole is provided on the upper end face of the spray net pipe, the heat exchange tube includes an inlet pipe passing through the shell, an outlet pipe passing through the shell and a heat exchange unit located in the shell, a water pump is provided on the inlet pipe, a plurality of heat exchange units are provided and connected to each other, and the heat exchange units at the upper and lower ends are respectively connected to one of the inlet pipe and the outlet pipe. The wastewater contacts all the heat exchange tubes during the upward spraying and falling process, thereby extending the heat exchange time and fully recovering the heat energy.

[0004] During the operation of the boiler, various salts, minerals, suspended matter and other impurities will dissolve in the water, and the wastewater discharged into the fixed-discharge expansion tank has a high content of hardness ions such as calcium and magnesium. The method of increasing the heat exchange time by spraying wastewater in the above-mentioned patent can only increase the efficiency of heat recovery in the short term. After a long period of heat exchange between the wastewater and the heat exchange pipe, scale will form on the outer wall of the heat exchange pipe, thereby reducing the heat transfer efficiency and must be cleaned regularly. Once scale is formed, it will tightly adhere to the surface of the container or pipe to form a hard shell layer, which is difficult to remove by simple flushing or wiping. In addition, the space inside the fixed-discharge expansion tank is small, and the cleaning work is limited by space, resulting in cleaning tools being difficult to reach, and the cleaning work is very inconvenient. Summary of the invention

[0005] The purpose of the present invention is to solve the problem in the prior art that after wastewater and heat exchange pipes are heat exchanged for a long time, scale will form on the outer wall of the heat exchange pipe, thereby reducing the heat transfer efficiency, and a steam waste heat recovery and recycling device for a fixed-discharge expansion tank is proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A steam waste heat recovery and recycling device for a fixed-discharge expansion tank comprises a tank body, an exhaust pipe is arranged on the top of the tank body, a liquid inlet pipe is arranged on the side of the tank body, a sewage pipe is arranged on the bottom of the tank body, and a steam absorption component and a heat exchange component for absorbing the heat of high-temperature waste hot water and secondary steam are arranged in the tank body; The steam absorption assembly includes a spray pipe installed above the tank body and a flow guide fixed inside the tank body, a steam absorption zone is formed above the flow guide, and the spray pipe extends into the steam absorption zone; The heat exchange assembly includes an installation box, a steam buffer zone is formed between the installation box and the deflector, a pressure reduction and expansion zone is formed below the installation box, a plurality of horizontally arranged heat exchange tubes are rotatably arranged in the installation box, a U-shaped tube is sealably and rotatably arranged at the ends of the plurality of heat exchange tubes and are interconnected through the U-shaped tube to form a serpentine pipe for one-way flow, an input pipe and an output pipe extending outside the tank body are respectively installed at both ends of the serpentine pipe, a plurality of groups of buffer plate groups corresponding to the heat exchange tubes are arranged in the installation box, a belt drive mechanism is arranged between the plurality of heat exchange tubes, and the belt drive mechanism is driven by a motor fixedly installed on the outer wall of the tank body.

[0007] Preferably, the deflector comprises a plurality of concentrically arranged annular grooves, the plurality of annular grooves are distributed longitudinally to form two groups, the two groups of annular grooves are staggered and spaced apart, and the annular grooves in the same group are connected to the same deflection tube extending to the outside of the tank body.

[0008] Preferably, the cross section of the annular groove is an arc shape with the opening facing upward, and a gap for steam to pass through is reserved between the opening end of the annular groove located at the bottom and the bottom end of the annular groove located at an adjacent position above.

[0009] Preferably, a conical liquefaction hood is fixedly installed outside the spray pipe.

[0010] Preferably, the plurality of heat exchange tubes are distributed in multiple layers along the longitudinal direction, and the heat exchange tubes in each layer are distributed in an array at intervals.

[0011] Preferably, the buffer plate group includes a guide plate 1 and a guide plate 2 which are symmetrically arranged, wherein the guide plate 1 and the guide plate 2 are in contact with the wall of the heat exchange tube at one end close to the heat exchange tube and are inclined downward at the other end.

[0012] Preferably, the guide plate 1 and the guide plate 2 at the adjacent position are close to each other to form a flow channel, and the flow channel corresponds to the heat exchange tube at the adjacent position below.

[0013] Preferably, a descaling scraper is provided on the upper surface of the guide plate 1 where it is in contact with the heat exchange tube, and the descaling scraper is a hard metal scraper.

[0014] Preferably, a liquid collecting scraper is provided on the lower surface of the guide plate 2 where it is in contact with the heat exchange tube. The liquid collecting scraper is a rubber scraper. The bottom end of the guide plate 2 is bent toward one side of the heat exchange tube to form a curled edge to form a liquid collecting trough. The liquid collecting troughs located in the same plane are connected to the same guide tube 2, and multiple guide tubes 2 are connected to the same liquid outlet pipe extending to the outside of the tank body.

[0015] Preferably, the belt drive mechanism includes an external toothed pulley fixedly arranged on the outer wall of the heat exchange tube and the output end of the motor, and two adjacent layers of heat exchange tubes form a transmission group. The external toothed pulleys on the same transmission group are connected by an internal toothed belt one, and one of the external toothed pulleys in a different transmission group is connected to the external toothed pulley at the output end of the motor by an internal toothed belt two.

[0016] Compared with the prior art, the present invention has the following advantages: 1. The use of multiple heat exchange tubes distributed in an array effectively increases the contact area between the wastewater and the heat exchange tubes. In addition, the buffer plate group corresponding to each heat exchange tube effectively slows down the falling speed of the wastewater, prolongs the residence time of the wastewater around the heat exchange tube, thereby improving the adequacy and efficiency of the heat exchange. In addition, the figure-eight structure formed by the guide plate 1 and the guide plate 2 in the buffer plate group can not only effectively block and guide the wastewater into the secondary steam generated by the pressure reduction in the pressure reduction expansion area, but also enables these steam to perform secondary heat exchange with the bottom surface of the heat exchange tube, further improving the overall heat exchange efficiency.

[0017] 2. By setting a rotatable heat exchange tube and continuously rotating the heat exchange tube, not only the uniform distribution of wastewater on the surface of the heat exchange tube is promoted and the heat transfer efficiency is improved, but also the scale removal scraper on the guide plate 1 automatically removes the scale generated in the heat exchange process, effectively preventing the problem of reduced heat exchange efficiency caused by scale accumulation, extending the service life of the equipment, and reducing maintenance costs. The water collection scraper on the guide plate 2 collects the soft water formed after the bottom surface of the heat exchange tube and the secondary steam heat exchange condensation into the liquid collecting tank, realizing the secondary utilization of water resources and improving the comprehensive benefits of wastewater treatment.

[0018] 3. The flow path of the steam is effectively guided by setting up a flow guide, and desalted water is sprayed into the steam through a spray pipe, so that the desalted water and high-temperature steam are fully mixed and heat exchanged during the rising process, reducing the direct loss of high-temperature steam. The high-temperature desalted water that has absorbed heat is then collected and reused through the flow guide, which not only achieves efficient heat recovery, but also significantly reduces energy consumption and heat waste. After the desalted water sprayed out from the spray pipe is mixed with the high-temperature steam, the temperature of the steam can be effectively reduced, so that the final discharge meets the discharge temperature requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the internal structure of a steam waste heat recovery and recycling device for a fixed-discharge expansion tank proposed by the present invention; Figure 2 This is a schematic diagram of the appearance structure of a steam waste heat recovery and recycling device for a fixed-discharge expansion tank proposed by the present invention; Figure 3 This is a cross-sectional structural schematic diagram of a steam waste heat recovery and recycling device for a fixed-discharge expansion vessel proposed by the present invention; Figure 4 This is a schematic diagram of the structure of a flow guide in a steam waste heat recovery and recycling device for a fixed-discharge expansion vessel proposed by the present invention; Figure 5 A schematic diagram of the structure of a heat exchange component in a steam waste heat recovery and recycling device for a fixed-discharge expansion tank proposed by the present invention Figure 1 ; Figure 6 A schematic diagram of the structure of a heat exchange component in a steam waste heat recovery and recycling device for a fixed-discharge expansion tank proposed by the present invention Figure 2 ; Figure 7 This is a schematic diagram of the structure of heat exchange tubes in a steam waste heat recovery and recycling device for a fixed-discharge expansion vessel proposed by the present invention; Figure 8 This is a structural schematic diagram of the positional relationship between heat exchange tubes and buffer plate groups in a steam waste heat recovery and recycling device for a fixed-discharge expansion vessel proposed by the present invention.

[0020] In the figure: 1. tank body; 11. exhaust pipe; 12. liquid inlet pipe; 13. sewage pipe; 14. steam absorption area; 15. steam buffer zone; 16. pressure reduction expansion zone; 2. steam absorption assembly; 21. spray pipe; 211. liquefaction hood; 22. guide; 221. annular groove; 222. guide tube one; 3. heat exchange assembly; 31. installation box; 32. heat exchange tube; 33. buffer plate group; 331. guide plate one; 332. guide plate two; 333. descaling scraper; 334. liquid collection scraper; 335. liquid collection tank; 336. guide tube two; 34. input pipe; 35. output pipe; 36. U-shaped pipe; 37. liquid outlet pipe; 4. motor; 41. external toothed pulley; 42. internal toothed belt one; 43. internal toothed belt two. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0022] Reference Figure 1-3A device for recovering and recycling waste heat from steam in a fixed-discharge expansion tank comprises a tank body 1, an exhaust pipe 11 is arranged on the top of the tank body 1, a liquid inlet pipe 12 is arranged on the side of the tank body 1, a sewage pipe 13 is arranged on the bottom of the tank body 1, a steam absorption component 2 and a heat exchange component 3 for absorbing heat of high-temperature waste hot water and secondary steam are arranged in the tank body 1, the liquid inlet pipe 12 is connected to the drainage pipe of the boiler, and the high-temperature waste hot water discharged from the boiler is discharged into the tank body 1 through the liquid inlet pipe 12, wherein the high-temperature steam generated is absorbed by heat exchange through the steam absorption component 2, and the waste hot water is poured on the heat exchange component 3, and the heat in the waste hot water and the heat in the secondary steam formed by decompressing and reboiling the waste hot water are absorbed and converted through the heat exchange component 3, and finally discharged through the sewage pipe 13.

[0023] The steam absorption assembly 2 includes a spray pipe 21 installed above the tank body 1 and a deflector 22 fixed inside the tank body 1. A steam absorption area 14 is formed above the deflector 22. The spray pipe 21 extends into the steam absorption area 14. After the waste hot water enters the tank body 1, it is input to the bottom of the deflector 22, and steam is generated below the deflector 22. The steam rises and passes through the deflector 22 into the steam absorption area 14. Uniform water mist is sprayed out through the spray pipe 21 to fully combine with the steam in the rising process for heat exchange. Desalted water is introduced into the spray pipe 21. The steam generated by the waste hot water is combined with the desalted water, and the content of hardness ions such as calcium and magnesium is low. The hot water obtained by the mixed heat exchange has low hardness. After being collected by the deflector 22, it can be sent to the deaerator for reuse, thereby reducing the direct loss of high-temperature steam.

[0024] Reference Figure 1-4 The deflector 22 includes a plurality of concentrically arranged annular grooves 221, and the plurality of annular grooves 221 are distributed in the longitudinal direction to form two groups. The cross section of the annular grooves 221 is an arc shape with an opening upward. A gap for steam to pass through is reserved between the open end of the annular groove 221 located at the bottom and the bottom end of the annular groove 221 located at an adjacent position above. During the rising process of the steam, the steam enters the steam absorption area 14 through the gap. The sprayed desalted water is combined with the steam for heat exchange and falls into the annular grooves 221 for collection. The two groups of annular grooves 221 are staggered and spaced, so that the annular grooves 221 completely cover the cross section of the tank body 1 in the longitudinal projection, so that the falling spray water can be The annular groove 221 is completely collected, and the annular grooves 221 of the same group are connected to the same guide pipe 222 extending to the outside of the tank body 1. The mixed hot water collected in the annular groove 221 is transported to the outside of the tank body 1 for use through the guide pipe 222, which not only realizes the efficient recovery of heat, but also significantly reduces energy consumption and heat waste. The non-condensable gas is discharged into the atmosphere through the exhaust pipe 11 on the top of the tank body 1, and the spray water can also absorb the escaped secondary steam. After the desalted water sprayed from the spray pipe 21 is mixed with the high-temperature steam, the temperature of the steam can be effectively reduced, so that the final discharge meets the discharge temperature requirements.

[0025] A conical liquefaction hood 211 is fixedly installed outside the spray pipe 21. The liquefaction hood 211 plays a role in gas-liquid separation, reduces the risk of water escaping with steam, and improves resource utilization efficiency.

[0026] Reference Figure 1-3 and Figure 5-7 The heat exchange component 3 includes an installation box 31. A steam buffer 15 is formed between the installation box 31 and the guide 22. The output end of the liquid inlet pipe 12 is connected to the steam buffer 15. After the waste hot water enters the tank body 1, steam is formed in the steam buffer 15 and rises to the steam absorption area 14. A decompression expansion area 16 is formed below the installation box 31. After the waste hot water flows downward and enters the decompression expansion area 16, the waste hot water will form secondary steam when it boils due to the increase in space and the decrease in pressure. A plurality of horizontally arranged heat exchangers are rotatably arranged in the installation box 31. The heat pipe 32 and the installation box 31 are attached to the tank body 1 and fixedly connected to the tank body 1. The installation box 31 has a rectangular through hole inside, which is convenient for the installation of the heat exchange tube 32. The multiple heat exchange tubes 32 are distributed in multiple layers along the longitudinal direction. Each layer of heat exchange tubes 32 is arranged in an array at intervals. When in use, desalted water is passed into the heat exchange tube 32, and the waste hot water poured on the heat exchange tube 32 exchanges heat with the desalted water through the heat exchange tube 32, so that the desalted water is heated and heat recovery is achieved. The array-distributed heat exchange tubes 32 allow the waste hot water poured downward to exchange heat with different heat exchange tubes. The heat pipes 32 are in full contact, which effectively increases the contact area between the wastewater and the heat exchange pipes 32, and improves the sufficiency and efficiency of heat exchange. The ends of the multiple heat exchange pipes 32 are sealed and rotated with U-shaped pipes 36 and are interconnected through the U-shaped pipes 36 to form a serpentine pipe with one-way flow. The U-shaped pipes 36 are fixed in position, and the heat exchange pipes 32 can be rotated. The multiple heat exchange pipes 32 are connected into a serpentine pipe through the U-shaped pipes 36, which can ensure that the desalted water is kept sufficiently in the heat exchange pipes 32 after being input. In order to shorten the heat exchange time and improve the heat exchange effect, an input pipe 34 and an output pipe 35 extending to the outside of the tank body 1 are installed at both ends of the serpentine pipe respectively. The input pipe 34 is connected to the desalted water inlet pipe, and the output pipe 35 is connected to the deaerator and other equipment that needs hot water to achieve full utilization of hot water. A plurality of buffer plate groups 33 corresponding to the heat exchange tubes 32 are arranged in the installation box 31, which effectively slow down the falling speed of the waste hot water and prolong the residence time of the waste hot water around the heat exchange tubes 32, thereby improving the adequacy and efficiency of the heat exchange.

[0027] A belt drive mechanism is arranged between the multiple heat exchange tubes 32. The belt drive mechanism is driven by a motor 4 fixedly installed on the outer wall of the tank body 1. The motor 4 drives the belt drive mechanism, so that the heat exchange tube 32 rotates continuously. In conjunction with the buffer plate group 33, the scale formed on the outer surface of the heat exchange tube 32 can be effectively cleaned, thereby ensuring efficient heat exchange of the heat exchange tube 32.

[0028] Reference Figure 5-8The buffer plate group 33 includes a symmetrically arranged guide plate 1 331 and a guide plate 2 332. The guide plate 1 331 and the guide plate 2 332 are close to the heat exchange tube 32 at one end and are in contact with the wall of the heat exchange tube 32, and the other end is inclined downward. The contact position between the guide plate 1 331 and the guide plate 2 332 and the heat exchange tube 32 is the key position on both sides of the heat exchange tube 32, and the outer heat exchange surface of the heat exchange tube 32 is divided into an upper heat exchange surface and a lower heat exchange surface. The outer heat exchange surface of the guide plate 1 331 and the guide plate 2 332 The ends are inclined to form an eight-shape, which can effectively delay and guide the wastewater into the pressure reduction expansion zone 16, and prolong the residence time of the wastewater on the heat exchange surface of the heat exchange tube 32. On the other hand, after the waste hot water enters the pressure reduction expansion zone 16, the secondary steam formed by the pressure reduction will be intercepted by the guide plate 1 331 and the guide plate 2 332 under the heat exchange tube 32 during the rising process, so that these secondary steam can perform secondary heat exchange with the lower heat exchange surface of the heat exchange tube 32, thereby further improving the overall heat exchange efficiency.

[0029] Reference Figure 3 and Figure 5-8 The guide plate 1 331 and the guide plate 2 332 at the adjacent position are close to each other to form a flow channel, and the flow channel corresponds to the heat exchange tube 32 at the adjacent position below. Under the drainage of the waste hot water by the guide plate 1 331 and the guide plate 2 332, the waste hot water falls and acts on the heat exchange tube 32 below, which is beneficial to the heat exchange.

[0030] Driven by the motor 4, the plurality of heat exchange tubes 32 continuously rotate in one direction, and the upper heat exchange surface of the heat exchange tube 32 rotates toward the side of the guide plate 331. The upper surface of the guide plate 331 where the heat exchange tube 32 is in contact is provided with a descaling scraper 333. The descaling scraper 333 is a hard metal scraper. During the rotation of the heat exchange tube 32, the descaling scraper 333 continuously scrapes the surface of the heat exchange tube 32. Since the waste hot water is high-hardness waste water discharged from the boiler after long-term use, the content of hardness ions such as calcium and magnesium is high. The deposition of these hardness ions or impurities on the surface of the heat exchange tube 32 will form scale. The scraping of the descaling scraper 333 can clean the hard scale layer before it appears, thereby ensuring efficient heat exchange of the heat exchange tube 32. The scraped scale follows the waste hot water flow into the bottom of the tank body 1 and is discharged.

[0031] Reference Figure 5-8The lower surface of the guide plate 332 where the heat exchange tube 32 is attached is provided with a liquid collecting scraper 334, which is a rubber scraper. The lower heat exchange surface of the heat exchange tube 32 rotates toward the side of the guide plate 332. As the rotation proceeds, the liquid collecting scraper 334 scrapes off the condensed water condensed on the lower heat exchange surface, so that the condensed water flows downward along the guide plate 332. The bottom end of the guide plate 332 is bent toward the side of the heat exchange tube 32 to form a curling edge to form a liquid collecting groove 335. The condensed water is finally collected in the liquid collecting groove 335 along the guide plate 332. Since the liquid collecting groove 335 rolls inward, the waste hot water flows downward through the guide plate 332. The condensed water will not enter the collecting tank 335 and pollute the condensed water. The collecting tanks 335 located on the same plane are connected to the same guide pipe 336. Multiple guide pipes 336 are connected to the same liquid outlet pipe 37 extending to the outside of the tank body 1. The collected condensed water enters the liquid outlet pipe 37 through the guide pipe 336 for collection and use. Since the secondary steam oil waste hot water is evaporated, it is equivalent to a softening treatment. Most of the calcium and magnesium ions are removed from the condensed water formed on the heat exchange surface under the heat exchange tube 32, and its hardness is naturally low. Therefore, the condensed water can be recycled, realizing the secondary utilization of water resources and improving the comprehensive benefits of wastewater treatment.

[0032] Reference Figure 5-6 The belt transmission mechanism includes an external toothed pulley 41 fixedly arranged on the outer wall of the heat exchange tube 32 and the output end of the motor 4. Two adjacent layers of heat exchange tubes 32 form a transmission group. The external toothed pulleys 41 on the same transmission group are connected by an internal toothed belt one 42. One of the external toothed pulleys 41 in different transmission groups is connected to the external toothed pulley 41 at the output end of the motor 4 by an internal toothed belt two 43. After the motor 4 is started, it drives the different transmission groups to move, and then drives all the external toothed pulleys 41 to rotate, so as to drive the heat exchange tube 32. The outer periphery of the external toothed pulley 41 has external teeth, and the internal toothed belt one 42 and the internal toothed belt two 43 have internal teeth. The cooperation of the internal teeth and the external teeth can improve the stability of the transmission.

[0033] The specific working principle of the present invention is as follows: When in use, the liquid inlet pipe 12 is connected to the drainage pipe of the boiler, and the high-temperature waste hot water discharged from the boiler is discharged into the tank body 1 through the liquid inlet pipe 12, and steam is formed in the steam buffer area 15. During the rising process of the steam, the steam enters the steam absorption area 14 through the gap, and the uniform desalted water mist is sprayed out through the spray pipe 21 to fully combine with the steam in the rising process for heat exchange. The falling spray water can be completely collected by the annular groove 221, and the non-condensable gas is discharged into the atmosphere through the exhaust pipe 11 on the top of the tank body 1, which not only realizes the efficient recovery of heat, but also significantly reduces energy consumption and heat waste.

[0034] At the same time, the waste hot water is poured on the heat exchange tube 32 and flows downward into the pressure reduction expansion zone 16. When in use, desalted water is introduced into the heat exchange tube 32, and the waste hot water poured on the heat exchange tube 32 exchanges heat with the desalted water through the heat exchange tube 32, so that the desalted water is heated and heat recovery is achieved. The outer ends of the guide plate 1 331 and the guide plate 2 332 are inclined to form an eight-shaped shape, which can effectively delay and guide the waste water into the pressure reduction expansion zone 16, and prolong the residence time of the waste water on the heat exchange surface of the heat exchange tube 32. On the other hand, after the waste hot water enters the pressure reduction expansion zone 16, the secondary steam formed by the pressure reduction will be intercepted by the guide plate 1 331 and the guide plate 2 332 under the heat exchange tube 32 during the rising process, so that these secondary steam can be subjected to secondary heat exchange with the lower heat exchange surface of the heat exchange tube 32, thereby further improving the overall heat exchange efficiency.

[0035] Driven by the motor 4, the plurality of heat exchange tubes 32 continuously rotate in one direction. During the rotation of the heat exchange tubes 32, the descaling scraper strips 333 continuously scrape the surface of the heat exchange tubes 32. The descaling scraper strips 333 can clean the hard scale layer before it appears, thereby ensuring efficient heat exchange of the heat exchange tubes 32. The scraped scale follows the waste hot water flow into the bottom of the tank body 1 for discharge. At the same time, the liquid collection scraper strips 334 scrape the condensed water condensed on the lower heat exchange surface, so that the condensed water flows downward along the guide plate 2 332 and is finally collected in the liquid collection tank 335 and enters the liquid outlet pipe 37 through the guide pipe 2 336 for collection and use, thereby realizing the secondary utilization of water resources and improving the comprehensive benefits of wastewater treatment.

Claims

1. A steam waste heat recovery and recycling device for a fixed-discharge expansion tank, comprising a tank body (1), an exhaust pipe (11) being arranged on the top of the tank body (1), a liquid inlet pipe (12) being arranged on the side of the tank body (1), and a sewage discharge pipe (13) being arranged on the bottom of the tank body (1), characterized in that: The tank body (1) is provided with a steam absorption component (2) and a heat exchange component (3) for absorbing heat of high-temperature waste hot water and secondary steam; The steam absorption assembly (2) comprises a spray pipe (21) installed above the tank body (1) and a flow guide (22) fixed inside the tank body (1), a steam absorption area (14) is formed above the flow guide (22), and the spray pipe (21) extends into the steam absorption area (14); The heat exchange assembly (3) comprises a mounting box (31), a steam buffer zone (15) is formed between the mounting box (31) and the deflector (22), a pressure reduction expansion zone (16) is formed below the mounting box (31), a plurality of horizontally arranged heat exchange tubes (32) are rotatably arranged in the mounting box (31), U-shaped tubes (36) are rotatably arranged at the ends of the plurality of heat exchange tubes (32) and are interconnected through the U-shaped tubes (36) to form a serpentine pipe for one-way flow, an input pipe (34) and an output pipe (35) extending to the outside of the tank body (1) are respectively installed at both ends of the serpentine pipe, a plurality of buffer plate groups (33) corresponding to the heat exchange tubes (32) are arranged in the mounting box (31), a belt transmission mechanism is arranged between the plurality of heat exchange tubes (32), and the belt transmission mechanism is driven by a motor (4) fixedly installed on the outer wall of the tank body (1).

2. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 1, characterized in that: The flow guide (22) comprises a plurality of concentrically arranged annular grooves (221), wherein the plurality of annular grooves (221) are distributed longitudinally to form two groups, wherein the two groups of annular grooves (221) are arranged at intervals and in a staggered manner, and the annular grooves (221) in the same group are connected to a same flow guide pipe 1 (222) extending to the outside of the tank body (1).

3. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 2, characterized in that: The cross section of the annular groove (221) is an arc shape with an opening upward, and a gap for steam to pass through is reserved between the opening end of the annular groove (221) located at the bottom and the bottom end of the annular groove (221) located at an adjacent position above.

4. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 1, characterized in that: A conical liquefaction cover (211) is fixedly mounted outside the spray pipe (21).

5. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 1, characterized in that: The plurality of heat exchange tubes (32) are distributed in multiple layers along the longitudinal direction, and the heat exchange tubes (32) in each layer are distributed in an array at intervals.

6. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 1, characterized in that: The buffer plate group (33) comprises a guide plate 1 (331) and a guide plate 2 (332) which are symmetrically arranged, wherein one end of the guide plate 1 (331) and the guide plate 2 (332) are close to the heat exchange tube (32) and are in contact with the tube wall of the heat exchange tube (32), and the other end is inclined downward.

7. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 6, characterized in that: The guide plate 1 (331) and the guide plate 2 (332) at an adjacent position are close to each other to form a flow channel, and the flow channel corresponds to the heat exchange tube (32) at an adjacent position below.

8. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 6, characterized in that: A descaling scraper (333) is provided on the upper surface of the portion where the guide plate 1 (331) and the heat exchange tube (32) are in contact with each other. The descaling scraper (333) is a hard metal scraper.

9. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 6, characterized in that: A liquid collecting scraper (334) is provided on the lower surface of the portion where the guide plate 2 (332) and the heat exchange tube (32) are in contact. The liquid collecting scraper (334) is a rubber scraper. The bottom end of the guide plate 2 (332) is bent toward one side of the heat exchange tube (32) to form a curled edge to form a liquid collecting groove (335). The liquid collecting grooves (335) located in the same plane are connected to the same guide tube 2 (336). The plurality of guide tubes 2 (336) are connected to the same liquid outlet pipe (37) extending to the outside of the tank body (1).

10. The device for recovering and recycling waste heat from steam of a fixed-discharge expansion vessel according to claim 1, characterized in that: The belt transmission mechanism comprises an external toothed pulley (41) fixedly arranged on the outer wall of the heat exchange tube (32) and the output end of the motor (4); two adjacent layers of heat exchange tubes (32) form a transmission group; the external toothed pulleys (41) on the same transmission group are connected to each other through an internal toothed belt 1 (42); and one of the external toothed pulleys (41) in a different transmission group is connected to the external toothed pulley (41) at the output end of the motor (4) through an internal toothed belt 2 (43).

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