High efficiency prying installation sewage heat method concentration device

Abstract

This invention relates to the field of wastewater treatment technology and relates to a high-efficiency skid-mounted thermal wastewater thickening device. It includes a movable skid-mounted support frame on which a thickening device is integrated. The thickening device comprises a first-effect evaporator and a last-effect evaporator. The heat source end of the first-effect evaporator is connected to a low-temperature heat source, and the condensate outlet of the first-effect evaporator is also connected to the low-temperature heat source via a steam-water balance pipeline. The heat source end of the last-effect evaporator is connected to the secondary steam outlet of the first-effect evaporator. This invention addresses the problems of traditional evaporation and thickening processes requiring extremely high-performance steam compressors, resulting in bulky equipment, large footprint, and inability to achieve multi-point mobile operation; the severe scaling inside heat exchange tubes caused by high-temperature evaporation of traditional high-concentration wastewater; and the high operating costs due to the direct discharge of latent heat from secondary steam and waste heat from condensate, which cannot be utilized in stages.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a high-efficiency skid-mounted thermal wastewater thickening device. Background Technology

[0002] With the continuous development of industrial production, the volume of wastewater requiring treatment is constantly increasing. In particular, industries such as chemical, power, pharmaceutical, food processing, machinery processing, and environmental water treatment generate large amounts of industrial wastewater that is high in salt, hardness, COD, and prone to scaling and corrosion. Direct discharge of this type of wastewater will not only waste water resources but also cause serious environmental pollution. Therefore, it is necessary to concentrate, reduce its volume, and treat it for resource recovery.

[0003] Currently, the treatment of the aforementioned wastewater mostly employs evaporation and concentration processes, such as single-effect evaporation, multi-effect evaporation, and MVR evaporation. However, existing evaporation equipment generally has problems.

[0004] The existing devices have gradually revealed their shortcomings with use, mainly in the following aspects: First, while existing evaporation and concentration technologies are energy-efficient, they place extremely high demands on the materials, control, and pretreatment of the steam compressor. The equipment is prone to scaling and corrosion. Furthermore, this technology results in large equipment sizes and large floor space requirements. Consequently, most of these evaporation devices are fixed structures that require on-site assembly and installation, leading to long construction periods. They cannot be used temporarily or rotated between multiple locations. They cannot meet the needs of emergency response, decentralized treatment, and temporary projects. Moreover, they are also limited by heat source conditions, resulting in unstable operation.

[0005] Secondly, traditional high-concentration wastewater flows inside the heat exchange tubes, and because the heat source is high-temperature evaporation above 100°C, the heat exchange tubes are severely scaled, the heat transfer efficiency drops rapidly, and frequent shutdowns for cleaning are required, affecting continuous operation and posing safety hazards to the system.

[0006] Third, existing evaporation systems generally suffer from insufficient heat recovery. The latent heat of secondary steam and the waste heat of condensate are mostly discharged directly, making it impossible to achieve cascade utilization and recycling. This results in huge steam consumption, high energy consumption, and high operating costs.

[0007] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a high-efficiency skid-mounted thermal wastewater concentration device. This device solves the problems of traditional evaporation concentration processes requiring extremely high-performance steam compressors, resulting in bulky equipment, large footprint, and inability to be used in multiple locations; traditional high-concentration wastewater undergoes high-temperature evaporation from heat sources, leading to severe scaling inside heat exchange tubes; and the latent heat of secondary steam and waste heat of condensate are mostly directly discharged without being utilized in stages, resulting in high operating costs.

[0009] To address the above problems, the present invention provides the following technical solution: A high-efficiency skid-mounted wastewater thermal thickening device includes a movable skid-mounted support, on which a thickening device is integrated. The thickening device includes a first-effect evaporator and a last-effect evaporator. The heat source end of the first-effect evaporator is connected to a low-temperature heat source, and the condensate outlet of the first-effect evaporator is also connected to the low-temperature heat source through a steam-water balance pipeline. The heat source end of the last-effect evaporator is connected to the secondary steam outlet of the first-effect evaporator.

[0010] As an optimized solution, the raw water inlets of the first-effect evaporator and the last-effect evaporator are connected to the raw water inlet pipeline through a preheater.

[0011] As an optimized solution, the concentrated water outlets of the first-effect evaporator and the last-effect evaporator are connected to a concentrated water discharge pipeline, and the concentrated water discharge pipeline is also connected to the raw water inlet pipeline through a circulating concentrated pipeline.

[0012] As an optimized solution, the inner cavities of the first-effect evaporator and the last-effect evaporator are connected to a negative pressure exhaust pipeline.

[0013] As an optimized solution, the secondary steam outlet of the final-effect evaporator is connected to a condenser, the condensate outlet of the condenser is connected to a product water tank, and the condensate outlet of the final-effect evaporator is also connected to the product water tank.

[0014] As an optimized solution, the raw water inlet pipeline is also connected to the condenser.

[0015] As an optimized solution, the product water tank is connected to a product pure water discharge pipeline via a product water pump.

[0016] As an optimized solution, the concentrated water discharge pipeline is located at the concentrated water outlet of the first-effect evaporator and the last-effect evaporator, and a concentrated water tank and a concentrated water pump are sequentially installed along the water outlet direction.

[0017] As an optimized solution, the steam-water balance pipeline is provided with a condensate tank and a condensate pump in sequence along the water outlet direction.

[0018] As an optimized solution, the low-temperature heat source is a steam generator.

[0019] As an optimized solution, a vacuum pump is connected to the negative pressure exhaust pipeline.

[0020] As an optimized solution, the low-temperature heat source is further connected to the heat source end of the first-effect evaporator via a preheating pipeline, and the outlet end of the preheating pipeline is connected to the condensate tank.

[0021] As an optimized solution, both the first-effect evaporator and the last-effect evaporator are falling film evaporation structures.

[0022] Compared with the prior art, the beneficial effects of the present invention are: This device utilizes a steam generator to generate low-temperature steam below 70℃ as a heat source, combined with negative pressure evaporation, abandoning the traditional high-temperature evaporation mode above 100℃. This effectively reduces the crystallization and scaling rate of wastewater on the heat exchange surface, significantly alleviates the problem of scaling and clogging of heat exchange tubes, reduces the frequency of downtime for cleaning, ensures continuous and stable operation of the system, and at the same time reduces the risk of equipment corrosion and extends its service life. The first-effect evaporator and the last-effect evaporator adopt a falling film evaporation structure, in which wastewater forms a film on the outer wall of the heat exchange tube and flows. This is different from the traditional forced circulation structure in which wastewater flows through the tube. Even if scale is generated, it is easier to clean. Structurally, it avoids the problem of scale inside the tube being difficult to clean and affecting system safety. The operation is more stable and the maintenance is simpler.

[0023] The secondary steam generated by the first-effect evaporator is directly used as the heat source for the last-effect evaporator, realizing the cascade utilization of thermal energy; at the same time, the waste heat of the steam in the last-effect evaporator is used to preheat the raw water, so that the thermal energy in the system is maximized to be recovered and recycled, significantly reducing steam consumption and energy consumption, solving the problems of insufficient thermal energy recovery and high operating costs of traditional devices, maximizing the recovery and utilization of system waste heat, significantly improving comprehensive energy efficiency, and making the heat source cost extremely low. By using preheating pipelines, the heat source of the steam generator is used to heat the preheater, enabling the system to supply heat to the preheater and improving the system's energy utilization rate. At the same time, the preheated condensate is recovered to the condensate tank and re-participates in the steam-water balance of the low-temperature heat source, further improving the energy efficiency and operating economy of the unit. The condensate from the first-effect evaporator flows back to the steam generator through the steam-water balance pipeline, forming a heat source water recycling system. This not only recovers heat but also achieves steam-water balance control, maintaining the system's water volume and heat balance. It eliminates the need for frequent replenishment of ambient temperature cold water, further reducing energy consumption. At the same time, it ensures stable evaporation pressure and temperature, improving operational stability and achieving a dual improvement in energy saving and system stability. This solves the problems of high energy consumption for water replenishment, large heat waste, and unstable operation in traditional systems. The concentrated water can be returned to the evaporator through the circulation pipeline for further concentration, achieving high concentration without increasing the equipment volume, improving the wastewater reduction rate, reducing the final discharge volume, and meeting the near-zero discharge requirements for high-salt wastewater. With the help of a vacuum pump, the system achieves a negative pressure environment, resulting in lower evaporation temperature and safer operation. It can adapt to complex water qualities such as high salt content, high hardness, easy scaling, and easy corrosion. Compared with traditional MVR systems, it does not require a high-requirement steam compressor, has lower material and control requirements, and is more stable and reliable in operation. This device achieves overall simplification through the aforementioned structure, enabling the entire device to be integrated onto a skid-mounted support. This allows for factory prefabrication, overall transportation, and rapid on-site installation and commissioning, eliminating the need for complex on-site construction, significantly shortening the construction cycle, and enabling the device to be flexibly moved and used in multiple locations. It can meet the needs of emergency sewage treatment, temporary projects, and decentralized wastewater treatment scenarios, overcoming the limitations of traditional fixed evaporation devices that occupy a large area and have a long installation cycle. This makes it more applicable and more flexible in deployment. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0025] Figure 1 This is a schematic diagram of the device structure of the present invention; Figure 2 This is a schematic diagram of the workflow of the present invention.

[0026] In the diagram: 1-Skid-mounted bracket; 2-First-effect evaporator; 3-Last-effect evaporator; 4-Raw water inlet pipeline; 5-Product pure water outlet pipeline; 6-Concentrated water outlet pipeline; 7-Negative pressure exhaust pipeline; 8-Steam-water balance pipeline; 9-Condensate tank; 10-Condensate pump; 11-Low-temperature heat source; 12-Condenser; 13-Preheater; 14-Product water tank; 15-Product water pump; 16-Concentrate tank; 17-Concentrate pump; 18-Preheating pipeline; 19-Circulating concentration pipeline. Detailed Implementation

[0027] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0028] like Figure 1 and Figure 2As shown, the high-efficiency skid-mounted wastewater thermal thickening device includes a movable skid-mounted support 1, on which a thickening device is integrated. The thickening device includes a first-effect evaporator 2 and a last-effect evaporator 3. The heat source end of the first-effect evaporator 2 is connected to a low-temperature heat source 11, and the condensate outlet of the first-effect evaporator 2 is also connected to the low-temperature heat source 11 through a steam-water balance pipeline 8. The heat source end of the last-effect evaporator 3 is connected to the secondary steam outlet of the first-effect evaporator 2.

[0029] The raw water inlets of the first-effect evaporator 2 and the last-effect evaporator 3 are connected to the raw water inlet pipeline 4 through the preheater 13.

[0030] The concentrated water outlets of the first-effect evaporator 2 and the last-effect evaporator 3 are connected to the concentrated water discharge pipeline 6, which is also connected to the raw water inlet pipeline 4 through the circulating concentrated pipeline 19.

[0031] The inner cavities of the first-effect evaporator 2 and the last-effect evaporator 3 are connected to a negative pressure exhaust pipe 7.

[0032] The secondary steam outlet of the last-effect evaporator 3 is connected to the condenser 12, the condensate outlet of the condenser 12 is connected to the product water tank 14, and the condensate outlet of the last-effect evaporator 3 is also connected to the product water tank 14.

[0033] The raw water inlet pipeline 4 is also connected to the condenser 12.

[0034] Product water tank 14 is connected to product pure water discharge pipeline 5 via product water pump 15.

[0035] The concentrated water discharge pipeline 6 is located at the concentrated water outlet of the first-effect evaporator 2 and the last-effect evaporator 3. Along the water outlet direction, a concentrated water tank 16 and a concentrated water pump 17 are installed sequentially.

[0036] The steam-water balance pipeline 8 is equipped with a condensate tank 9 and a condensate pump 10 in sequence along the water outlet direction.

[0037] Low-temperature heat source 11 is a steam generator.

[0038] A vacuum pump is connected to the negative pressure exhaust line 7.

[0039] The low-temperature heat source 11 is connected to the heat source end of the first-effect evaporator 2 via a preheating pipeline 18, and the outlet end of the preheating pipeline 18 is connected to the condensate tank 9.

[0040] Both the first-effect evaporator 2 and the last-effect evaporator 3 are falling film evaporation structures.

[0041] The pipeline is also equipped with on / off regulating valves, metering and detection instruments, which are well known in the field, so they will not be described in detail here.

[0042] The skid-mounted bracket 1 is also equipped with a dosing unit, including a dosing tank, a stirrer, a dosing pump and a dosing pipeline, which is used to deliver scale inhibitors and defoamers to the raw water inlet pipeline 4.

[0043] The skid-mounted bracket 1 is also equipped with an intelligent control unit, such as an integrated PLC / DCS control system, which monitors key parameters such as flow rate, temperature, pressure, and concentration (conductivity / pH) in real time, and automatically adjusts the steam volume, feed volume, circulation volume, and water production volume to achieve one-button start / stop and fully automatic operation. Multiple layers of supports can be installed on the skid-mounted bracket 1 to assemble and fix the above-mentioned structures.

[0044] The thermal concentration process flow of this device is as follows: The raw water is heated to near the operating temperature of the evaporator by low-temperature steam in the preheater 13; The preheated raw water enters the first-effect evaporator 2 and the last-effect evaporator 3, and is evenly distributed on the surface of the heat exchange tubes. It is heated and evaporated on the tube wall to generate secondary steam. The concentrated liquid in the first-effect evaporator 2 and the last-effect evaporator 3 is collected in the concentrated water tank 16, and then returned to the raw water inlet pipeline 4 via the concentrated water pump 17 and the circulating concentrated pipeline 19 for further circulation and concentration until the designed concentration is reached and then discharged. The steam condensate from the first-effect evaporator 2 is recovered to the condensate tank 9, and then sent back to the steam generator via the condensate pump 10 to maintain the steam-water balance. The secondary steam from the first-effect evaporator 2 enters the last-effect evaporator 3 as a heat source for repeated operation, and the condensate from the last-effect evaporator 3 is connected to the product water tank 14. The secondary steam from the final-effect evaporator 3 is condensed and recovered by the condenser 12 to the product water tank 14, which is the pure water of the product. The intelligent control unit can automatically start and adjust according to operating parameters or requirements to meet the user's need for reduced concentrated brine.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A high-efficiency skid-mounted thermal wastewater thickening device, characterized in that: The device includes a movable skid-mounted bracket (1), on which a concentration device is integrated. The concentration device includes a first-effect evaporator (2) and a last-effect evaporator (3). The heat source end of the first-effect evaporator (2) is connected to a low-temperature heat source (11). The condensate outlet of the first-effect evaporator (2) is also connected to the low-temperature heat source (11) through a steam-water balance pipeline (8). The heat source end of the last-effect evaporator (3) is connected to the secondary steam outlet of the first-effect evaporator (2).

2. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 1, characterized in that: The raw water inlets of the first-effect evaporator (2) and the last-effect evaporator (3) are connected to the raw water inlet pipeline (4) through the preheater (13).

3. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 2, characterized in that: The concentrated water outlets of the first-effect evaporator (2) and the last-effect evaporator (3) are connected to the concentrated water discharge pipeline (6), and the concentrated water discharge pipeline (6) is also connected to the raw water inlet pipeline (4) through the circulating concentrated pipeline (19).

4. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 1, characterized in that: The inner cavities of the first-effect evaporator (2) and the last-effect evaporator (3) are connected to a negative pressure exhaust line (7), and a vacuum pump is connected to the negative pressure exhaust line (7).

5. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 2, characterized in that: The secondary steam outlet of the last-effect evaporator (3) is connected to a condenser (12), the condensate outlet of the condenser (12) is connected to a product water tank (14), and the condensate outlet of the last-effect evaporator (3) is also connected to the product water tank (14); the raw water inlet pipeline (4) is connected to the condenser (12).

6. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 5, characterized in that: The product water tank (14) is connected to a product pure water discharge pipeline (5) via a product water pump (15).

7. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 3, characterized in that: The concentrated water discharge pipeline (6) is located at the concentrated water outlet of the first-effect evaporator (2) and the last-effect evaporator (3), and is provided with a concentrated water tank (16) and a concentrated water pump (17) in sequence along the water outlet direction.

8. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 2, characterized in that: The steam-water balance pipeline (8) is provided with a condensate tank (9) and a condensate pump (10) in sequence along the water outlet direction.

9. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 1, characterized in that: The low-temperature heat source (11) is a steam generator.

10. The high-efficiency skid-mounted thermal wastewater thickening device according to claim 8, characterized in that: The low-temperature heat source (11) is connected to the heat source end of the first-effect evaporator (2) via a preheating pipeline (18), and the outlet end of the preheating pipeline (18) is connected to the condensate tank (9).

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