Evaporative sewage treatment system and treatment method

Abstract

The invention relates to the technical field of sewage heat treatment, and particularly discloses an evaporative sewage treatment system and a treatment method.The evaporative sewage treatment system comprises a falling film evaporator which comprises a heat accumulation bin and a heat exchange tube, and further comprises a separator communicated with the falling film evaporator and internally provided with a heating unit used for generating steam; the compressor is communicated with the separator, a preheating cleaning mechanism is arranged at the output end of the compressor, and the preheating cleaning mechanism comprises a main output pipe. By means of the gathering pipe and the heating through pipe which are arranged on the main output pipe of the compressor, in the preheating stage, steam is generated in the separator through the heating unit, the steam is compressed and heated through the compressor, the steam is directly poured into the heat exchange pipe along the gathering pipe to be preheated, the preheated steam can directly flow circularly, the preheating time is shortened, and the heat exchange efficiency is improved. And the steam is in direct contact with the inner wall of the heat exchange tube, so that dirt on the inner wall of the heat exchange tube is cleaned through the steam, and the disassembly cleaning time is prolonged.

Description

Technical Field

[0001] This invention relates to wastewater thermal treatment technology, specifically an evaporative wastewater treatment system and treatment method. Background Technology

[0002] As is widely known, MVR, also known as mechanical vapor recompression, is the mainstream artificial evaporation technology in industry for the thermal treatment of wastewater. Because it uses electric power to drive the compressor to recover heat energy, it has extremely high thermal efficiency.

[0003] For example, the invention patent with publication number CN107879534A, publication date April 6, 2018, entitled "A Rapid and Efficient Wastewater Treatment System Based on MVR", includes a sludge storage tank. A drain pipe is installed on the left side wall of the sludge storage tank, and a filter device is connected to the right end of the sludge storage tank via a pipe. This invention, through the setting of the filter box, allows the industrial wastewater pumped by the water pump to undergo initial filtration, reducing large particulate matter in the industrial wastewater and minimizing damage to other equipment. Through the setting of the centrifugal filter pump, small particulate matter in the industrial wastewater after filtration by the filter box can be filtered, reducing the content of crystalline impurities when the MVR distillation wastewater treatment device treats industrial wastewater. The MVR distillation wastewater treatment device allows for the recovery of water resources and industrial salt from industrial wastewater, saving resources. At the same time, the MVR distillation wastewater treatment device requires fewer public works facilities, resulting in lower total investment and reduced construction costs. Furthermore, it occupies a small area, saving space.

[0004] The shortcomings of existing technologies are that the equipment needs to be preheated before the MVR system is used to raise the temperature of the entire system. After a period of use, scale easily forms on the heat exchange tubes, requiring manual cleaning. Both preheating and cleaning require a long time of manual preparation and are carried out separately, resulting in high maintenance and cleaning frequency and significant labor and downtime costs. Summary of the Invention

[0005] The purpose of this invention is to provide an evaporative wastewater treatment system and method to address the aforementioned shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an evaporative wastewater treatment system, comprising a falling film evaporator, which includes a heat accumulation chamber and heat exchange tubes, and further comprising: A separator connected to the falling film evaporator is provided with a heating unit for generating steam. A compressor connected to the separator is provided with a preheating and cleaning mechanism at its output end. The preheating and cleaning mechanism includes a main output pipe, which is connected to a collecting pipe and a heating pipe, respectively. The gas collection pipe supplies gas to the heat exchange pipe, and the heating pipe supplies gas to the heat accumulation chamber.

[0007] As a further description of the above technical solution: the diameter of the collecting tube is smaller than that of the main output tube, so that the gas can be introduced along the heat exchange tube.

[0008] As a further description of the above technical solution: an adjusting baffle is rotatably connected to the main output pipe, and the adjusting baffle is driven to rotate and block the collecting pipe or the heating pipe.

[0009] As a further description of the above technical solution: the falling film evaporator also includes an aggregation chamber connected to the separator, and both the separator and the aggregation chamber are provided with a feed pipe.

[0010] As a further description of the above technical solution: a limiting cover is rotatably connected inside the separator. The limiting cover is driven to lock and restrict the airflow from moving toward the inner wall of the separator. The limiting cover rotates with the airflow to agitate the liquid at the bottom of the separator.

[0011] As a further description of the above technical solution: the limiting cover includes a cone cover, on which inclined blades are arranged in a circumferential array, and the first end of the inclined blades is submerged in the liquid at the bottom of the separator.

[0012] As a further description of the above technical solution: the separator and the aggregation chamber are connected by two connecting pipes, and the inner wall of the separator is provided with a side ring channel corresponding to the connecting pipe.

[0013] As a further description of the above technical solution: a limiting column is movably arranged in the feed pipe of the separator, and the limiting column is driven to fit against the limiting cover and lock.

[0014] As a further description of the above technical solution: a gradient angle is provided between the collecting tube and the main output tube, and the adjusting baffle covers ≥50% of the inner wall of the main output tube.

[0015] An evaporative wastewater treatment method specifically includes the following steps: S01, Preheating and Cleaning: Add liquid to the separator and start the heating unit and compressor. The steam enters the heat exchange tube along the collecting tube for cleaning, and then enters the collecting chamber and returns to the separator for preheating cycle. S02, Feeding: Extract the clean liquid from the separator and the collection chamber, switch the main output pipe to the heat accumulation chamber, and add wastewater to the top of the falling film evaporator; S03, Evaporation Recovery: Wastewater is heated along the heat exchange tube to form a steam mixture, which enters the collection chamber for separation. The steam then enters the separator for further separation, and is compressed and heated by the compressor before being sent to the heat accumulation chamber for reuse.

[0016] In the above technical solution, the present invention provides an evaporative sewage treatment system and method. Through the collection pipe and heating pipe set on the main output pipe of the compressor, during the preheating stage, steam is generated in the separator by the heating unit and heated by the compressor. The steam is directly injected into the heat exchange tube along the collection pipe for preheating, so that the preheated steam can circulate directly, accelerate the preheating time, and the steam directly contacts the inner wall of the heat exchange tube, thereby cleaning the dirt on the inner wall of the heat exchange tube with steam and extending the time for disassembly and cleaning. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention; Figure 2 This is an exploded view of the structure of a falling film evaporator provided in an embodiment of the present invention; Figure 3 This is an exploded view of the separator provided in an embodiment of the present invention; Figure 4 This is a schematic cross-sectional view of the preheating and cleaning mechanism provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the separator and confinement cover provided in an embodiment of the present invention; Figure 6 for Figure 5 Enlarged view of point A in the middle; Figure 7 This is a schematic diagram of the preheating and cleaning mechanism provided in an embodiment of the present invention; Figure 8 This is a schematic cross-sectional view of the overall structure provided in an embodiment of the present invention; Figure 9 for Figure 8 Enlarged view of point B in the middle; Figure 10 for Figure 8 Enlarged diagram of point C in the middle.

[0019] Explanation of reference numerals in the attached figures: 1. Falling film evaporator; 11. Heat exchange tube; 12. Heat accumulation chamber; 13. Gathering chamber; 131. First feed pipe; 14. Top discharge area; 141. Diverter; 142. Top cover plate; 2. Separator; 20. Second feed pipe; 21. Restriction hood; 210. Bottom lock; 211. Inclined blades; 212. Conical hood; 213. Side groove; 214. Rotating vane; 22. Collection hood; 23. Restriction column; 24. Side ring channel; 3. Compressor; 4. Preheating and cleaning mechanism; 41. Main output pipe; 42. Interface; 43. Adjustment baffle; 431. Extension rod; 44. Gathering pipe; 441. Gradient angle; 45. Heating pipe; 5. Connecting pipe. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. Example 1

[0021] Please see Figure 1-10 This invention provides a technical solution: an evaporative wastewater treatment system, including a falling film evaporator 1, which includes a heat accumulation chamber 12 and heat exchange tubes 11, and further includes: The separator 2, which is connected to the falling film evaporator 1, is equipped with a heating unit for generating steam. The compressor 3 is connected to the separator 2. The output end of the compressor 3 is equipped with a preheating and cleaning mechanism 4. The preheating and cleaning mechanism 4 includes a main output pipe 41, which is connected to the collecting pipe 44 and the heating pipe 45 respectively. Among them, the collecting pipe 44 supplies gas to the heat exchange pipe 11, and the heating pipe 45 supplies gas to the heat accumulation chamber 12.

[0022] Specifically, the heat exchange tubes 11 of the falling film evaporator 1 are installed in the heat accumulation chamber 12. The top of the heat exchange tubes 11 is provided with a top row area 14 for feeding, and the bottom of the heat exchange tubes 11 is provided with a collection chamber 13 connected to the separator 2. The separator 2 is provided with a heating unit for generating steam. The top of the separator 2 is connected to the main output pipe 41. The compressor 3 is an air compressor. The compressor 3 draws the gas in the separator 2, compresses it and heats it. The heated steam is output as hot gas flow (steam) along the main output pipe 41. During preheating, the hot gas flow enters the top row area 14 along the collection pipe 44 and then directly participates in the circulation in the heat exchange tubes 11 for full preheating. At the same time as preheating, the heat exchange tubes 11 are cleaned to clean the dirt attached to the top row area 14 and the inner wall of the heat exchange tubes 11, thereby extending the maintenance time for disassembly and cleaning.

[0023] After the cleaning and preheating steps, the output path of the main output pipe 41 is switched to the heat accumulation chamber 12, so that the steam accumulates heat in the heat accumulation chamber 12. The sewage to be treated is input along the top discharge area 14 and flows down from the heat exchange tube 11 to heat the steam in the sewage. The steam then flows back along the collection chamber 13, separator 2 and compressor 3, and recirculates back to the heat accumulation chamber 12 to continue heating the heat exchange tube 11.

[0024] Furthermore, the steam entering the separator 2 is generated by the heating unit and can also be transported through pipelines to other external equipment heated by steam. The top of the separator 2 is equipped with a collection hood 22, and a connecting pipe 5 is fixedly connected between the collection hood 22 and the compressor 3.

[0025] In the above scheme, through the gathering pipe 44 and heating pipe 45 set on the main output pipe 41 of the compressor 3, steam is generated in the separator 2 by the heating unit during the preheating stage. After being compressed and heated by the compressor 3, the steam is directly injected into the heat exchange tube 11 along the gathering pipe 44 for preheating. This allows the preheated steam to circulate directly, accelerating the preheating time. The steam also directly contacts the inner wall of the heat exchange tube 11, thereby cleaning the dirt on the inner wall of the heat exchange tube 11 with steam and extending the time for disassembly and cleaning.

[0026] In another embodiment of the present invention, the diameter of the collecting tube 44 is smaller than that of the main output tube 41 so that the gas is introduced along the heat exchange tube 11.

[0027] Specifically, a diverter 141 for uniformly dispersing sewage is installed in the top discharge zone 14. The diverter 141 is covered with a top cover plate 142. A discharge pipe and a collection pipe 44 are fixedly connected to the top cover plate 142. The top cover plate 142 is fixed to the top discharge zone 14 with screws for sealing. The diameter of the collection pipe 44 is smaller than that of the main output pipe 41, so that during the preheating stage, the temperature of the hot steam in the main output pipe 41 is increased again after compression in the collection pipe 44.

[0028] In another embodiment of the present invention, an adjusting baffle 43 is rotatably connected to the main output pipe 41, and the adjusting baffle 43 is driven to rotate and block the collecting pipe 44 or the heating pipe 45.

[0029] Specifically, an interface 42 is provided on the main output pipe 41, and an adjusting baffle 43 is rotatably connected to the interface 42. The adjusting baffle 43 is used to... Figure 4 For reference, it is semi-cylindrical to block the collecting pipe 44 or heating pipe 45. The part of the adjusting baffle 43 facing the outside is provided with an extension rod 431. The extension rod 431 is used to operate the adjustment baffle 43 to rotate to adapt to the preheating stage and the use stage.

[0030] Preferably, the falling film evaporator 1 further includes an accumulation chamber 13 connected to the separator 2. The separator 2 has a second discharge pipe 20 at its bottom and the accumulation chamber 13 has a first discharge pipe 131 at its bottom. During the preheating stage or the use stage, steam will condense and accumulate along the inner wall of the accumulation chamber 13 and the separator 2, so that the condensed liquid can be discharged through the second discharge pipe 20 and the first discharge pipe 131.

[0031] In another embodiment of the present invention, a limiting cover 21 is rotatably connected inside the separator 2. The limiting cover 21 is driven to lock and restrict the airflow from moving toward the inner wall of the separator 2. The limiting cover 21 rotates with the airflow to agitate the liquid at the bottom of the separator 2.

[0032] Specifically, a support ring is provided on the inner wall of the separator 2, and the limiting cover 21 is rotatably connected to the support ring. During the preheating stage, water (30mm~60mm above the bottom of the limiting cover 21) is added to the separator 2. Then, during the preheating stage, the water at the bottom is heated by the heating unit (the heating unit can be a heating rod) to generate steam. At the same time, the compressor 3 is started to drive the gas to circulate. When the circulating gas enters the separator 2 along the collection chamber 13, it will drive the unlocked limiting cover 21 to rotate. Thus, before the water at the bottom is heated to boiling, the limiting cover 21 stirs the water and drives the water to flow. When heating the single-point heating unit, it increases the water's temperature rise rate. During the use stage, the limiting cover 21 is locked. At this time, when the steam in the collection chamber 13 enters the separator 2, the airflow is guided by the limiting cover 21 to impact the inner wall of the separator 2, causing the water in the mixed steam to condense on the inner wall of the separator 2, which helps to condense water droplets.

[0033] Preferably, the separator 2 and the collection chamber 13 are connected by two connecting pipes 5. The limiting cover 21 includes a conical cover 212, on which inclined blades 211 are arranged in a circumferential array. The first end of the inclined blades 211 (with...) Figure 3 For reference, the liquid submerged at the bottom of the separator 2 (with the first end being the lower end) flows along the inclined blades 211 when the limiting cover 21 is locked. The airflow along the inclined blades 211 flows towards the inner wall of the separator 2, assisting the condensation of water droplets in the mixed airflow. At the same time, water droplets will also condense when the liquid impacts the inclined blades 211. Rotating plates 214 are provided (welded) at both ends of the inclined blades 211, and the rotating plates 214 are rotatably connected to the support ring.

[0034] Furthermore, the separator 2 and the collection chamber 13 are connected by two connecting pipes 5. The inner wall of the separator 2 is provided with a side ring channel 24 corresponding to the connecting pipe 5. When the airflow in the collection chamber 13 flows along the connecting pipe 5, a small part enters the side ring channel 24 for diffusion and then enters the inclined blade 211, while most of it directly impacts the side ring channel 24. The inclined blade 211 is provided with a side groove 213 corresponding to the side ring channel 24.

[0035] Preferably, a limiting post 23 is movably disposed in the feed pipe of the separator 2. Liquid accumulates at the second feed pipe 20 on the separator 2, and the liquid can seal the limiting post 23. One end of the limiting post 23 is fixed to the output end of the drive unit (the drive unit can be a telescopic motor or a telescopic cylinder). A bottom locking part 210 is provided at the bottom of the limiting cover 21. The limiting post 23 is driven to fit against the bottom locking part 210 to lock the limiting cover 21.

[0036] Furthermore, the limiting cover 21 can be replaced by the output end of the motor connected to the limiting cover 21, so that the active operation replaces the passive operation. The limiting cover 21 can be directly driven to rotate by the motor, or the motor can be stopped and locked by its self-locking mechanism.

[0037] In another embodiment of the present invention, a gradient angle 441 is provided between the collecting tube 44 and the main output tube 41, and the adjusting baffle 43 covers ≥50% of the inner wall of the main output tube 41.

[0038] Specifically, the gradient angle 441 is used to guide the hot steam from the main output pipe 41 to compress into the small-diameter collecting pipe 44. The adjusting baffle 43 covers ≥50% of the inner wall of the main output pipe 41 to ensure that the adjusting baffle 43 completely blocks the other pipe when the collecting pipe 44 or the heating pipe 45 is fully open. Example 2

[0039] This invention provides a technical solution: an evaporative wastewater treatment method, specifically including the following steps: S01, Preheating and Cleaning: First, rotate the adjusting baffle 43 to connect the main output pipe 41 to the collecting pipe 44. Then, add liquid to the separator 2 and start the heating unit to generate steam (or connect a new pipe to directly add steam). Next, start the compressor 3 to draw the steam in the separator 2, and output the steam from the main output pipe 41. The steam will then enter the heat exchange tube 11 through the collecting pipe 44 for cleaning. Then, it will enter the collecting chamber 13 and return to the separator 2 for preheating circulation. When the airflow returns to the separator 2, it will push the limiting cover 21 to rotate and stir the liquid in the separator 2. S02, Feeding: After preheating, the clean liquid in the separator 2 and the collection chamber 13 is extracted, and the adjusting baffle 43 is rotated to switch the main output pipe 41 to the heat accumulation chamber 12. Then the limiting cover 21 is locked, and wastewater is added to the top of the falling film evaporator 1. S03, Evaporation Recovery: Wastewater is diverted along the distributor 141 on the top discharge zone 13 into multiple heat exchange tubes 11, where it is heated to form a steam mixture. The mixture then enters the collection chamber 13 for separation, separating it into a viscous wastewater and a steam mixture. The steam mixture enters the separator 2, where it is guided by the inclined blades 211 and further separated along the inner wall of the separator 2. This causes the viscous wastewater to accumulate at the bottom of the separator 2 and the collection chamber 12 for easy discharge. Subsequently, the steam in the separator 22 is drawn off, compressed and heated by the compressor 3, and then transported to the heat accumulation chamber 12 for reuse.

[0040] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An evaporative wastewater treatment system, comprising a falling film evaporator (1), which includes a heat accumulation chamber (12) and heat exchange tubes (11), characterized in that, Also includes: A separator (2) connected to the falling film evaporator (1) is provided with a heating unit for generating steam. A compressor (3) connected to the separator (2) is provided with a preheating and cleaning mechanism (4) at the output end of the compressor (3). The preheating and cleaning mechanism (4) includes a main output pipe (41), which is connected to a gathering pipe (44) and a heating pipe (45) respectively. The gathering pipe (44) supplies gas to the heat exchange pipe (11), and the heating pipe (45) supplies gas to the heat accumulation chamber (12).

2. The evaporative wastewater treatment system according to claim 1, characterized in that, The diameter of the collecting tube (44) is smaller than that of the main output tube (41) so that gas can be introduced along the heat exchange tube (11).

3. The evaporative wastewater treatment system according to claim 1, characterized in that, An adjusting baffle (43) is rotatably connected to the main output pipe (41), and the adjusting baffle (43) is driven to rotate and block the collecting pipe (44) or the heating pipe (45).

4. The evaporative wastewater treatment system according to claim 1, characterized in that, The falling film evaporator (1) also includes an aggregation chamber (13) connected to the separator (2), and both the separator (2) and the aggregation chamber (13) are provided with a feed pipe.

5. The evaporative wastewater treatment system according to claim 4, characterized in that, A limiting cover (21) is rotatably connected inside the separator (2). The limiting cover (21) is driven to lock and restrict the airflow to move towards the inner wall of the separator (2). The limiting cover (21) rotates with the airflow to agitate the liquid at the bottom of the separator (2).

6. The evaporative wastewater treatment system according to claim 5, characterized in that, The limiting cover (21) includes a cone cover (212), on which inclined blades (211) are arranged in a circumferential array, and the first end of the inclined blades (211) is submerged in the liquid at the bottom of the separator (2).

7. The evaporative wastewater treatment system according to claim 5, characterized in that, The separator (2) and the aggregation chamber (13) are connected by two connecting pipes (5), and the inner wall of the separator (2) is provided with a side ring channel (24) corresponding to the connecting pipe (5).

8. The evaporative wastewater treatment system according to claim 5, characterized in that, A limiting post (23) is movably installed in the feed pipe of the separator (2), and the limiting post (23) is driven to fit against the limiting cover (21) and lock.

9. An evaporative wastewater treatment system according to claim 3, characterized in that, A gradient angle (441) is provided between the collecting tube (44) and the main output tube (41), and the adjusting baffle (43) covers ≥50% of the inner wall of the main output tube (41).

10. An evaporative wastewater treatment method, characterized in that, The evaporative wastewater treatment system according to any one of claims 1-9 specifically includes the following steps: S01, Preheating and Cleaning: Add liquid to the separator (2) and start the heating unit and compressor (3). The steam enters the heat exchange tube (11) through the gathering tube (44) for cleaning, and then enters the gathering chamber (13) and returns to the separator (2) for preheating cycle. S02, Feeding: Extract the clean liquid from the separator (2) and the collection chamber (13), switch the main output pipe (41) to the heat accumulation chamber (12), and add sewage to the top of the falling film evaporator (1); S03, Evaporation and Recovery: Wastewater is heated along the heat exchange tube (11) to form a steam mixture, which enters the collection chamber (13) for separation. The steam enters the separator (2) for further separation, and the steam is compressed and heated along the compressor (3) and transported to the heat accumulation chamber (12) for reuse.

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