A device and method for treating metal descaling wastewater

Abstract

This application relates to a metal descaling wastewater treatment device and method. The metal descaling wastewater treatment device includes: a descaling unit, a sedimentation unit, a water treatment unit, a heat exchange unit, a fine filtration unit, and a rinsing unit. A cyclone separation unit is provided between the descaling unit and the sedimentation unit, and the cyclone separation unit is connected to both the descaling unit and the water treatment unit via pipelines. The heat exchange unit and the fine filtration unit are connected to the water treatment unit via pipelines. The rinsing unit includes a rinsing component and a rinsing component. The heat exchange unit is connected to the rinsing component via a pipeline, and the fine filtration unit is connected to the rinsing component via a pipeline. The rinsing unit is connected to the descaling unit via a pipeline to return the rinsing water to the descaling unit for recycling. This can reduce the pollution caused by descaling wastewater to the environment. This invention can effectively improve the recycling rate of water and abrasive, achieve pollution treatment of descaling wastewater, and reduce the pollution caused by descaling wastewater to the environment.

Description

Technical Field

[0001] This application relates to the field of water pollution control technology, and more specifically, to a metal descaling wastewater treatment device and treatment method. Background Technology

[0002] During the rolling process of metal materials, especially in the production of hot-rolled metal plates or coils, the metal slab will oxidize when heated in the furnace, forming a layer of material called oxide scale. It mainly includes primary oxide scale and secondary oxide scale. Because there are dense cracks on the surface after cooling, resembling fish scales, it is generally called scale skin.

[0003] If these oxide scales are not removed in time before entering the next processing step, they will not only be pressed into the metal surface during the rolling process, significantly reducing the surface quality of the finished metal product, but also accelerate the wear of the rolls, thereby affecting production efficiency and product quality.

[0004] Hybrid jet descaling technology uses a water jet to carry fine hard particles, collectively known as abrasives or media. The water jet accelerates the hard particles to a sufficiently high speed and then washes and bombards the target object, thereby effectively cleaning corrosive layers such as rust, scale, paint, and burrs on the edges and corners of various products.

[0005] Abrasives are expensive and water consumption is enormous. Both abrasives and water need to be recycled. In actual mixed jet descaling production, if the media produced after descaling cannot be recycled, the water consumption will become enormous.

[0006] In addition, the wastewater in the descaling media contains pollutants such as detached iron oxide scale, oil, suspended solids, and potentially dissolved metal ions. If it is not properly recycled and treated, it will cause serious water pollution. Summary of the Invention

[0007] The purpose of this application is to provide a metal descaling wastewater treatment device and method, which can effectively improve the recycling rate of water and abrasive in the metal descaling medium, and achieve pollution treatment of descaling wastewater, thereby reducing the pollution caused by descaling wastewater to the environment.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a metal descaling wastewater treatment device, comprising: a descaling unit, a sedimentation unit, a water treatment unit, a heat exchange unit, a fine filtration unit, and a rinsing unit.

[0009] The sedimentation unit is located between the descaling unit and the water treatment unit. A cyclone separation unit is located between the descaling unit and the sedimentation unit. The cyclone separation unit is connected to the descaling unit and the water treatment unit respectively through pipelines.

[0010] A circulation backflow assembly is provided between the sedimentation unit and the descaling unit;

[0011] The heat exchange unit and the fine filtration unit are respectively connected to the water treatment unit through pipes, and the flushing and rinsing unit includes a flushing component and a rinsing component.

[0012] The heat exchange unit is connected to the flushing assembly via a pipe, and the fine filtration unit is connected to the rinsing assembly via a pipe;

[0013] The rinsing and washing unit is connected to the descaling unit via a pipe to return the rinsing and washing water to the descaling unit for recycling.

[0014] In an optional embodiment, the sedimentation unit includes a first sedimentation tank arranged in sequence, and the descaling unit includes a collection tank for receiving descaling wastewater. The collection tank is connected to the first sedimentation tank through a pipe, and the bottom of the first sedimentation tank is connected to the cyclone separation unit through a lift pump and a lift pipe.

[0015] In an optional embodiment, the cyclone separation unit includes multiple cyclone separators arranged in parallel, each of which is connected to a water outlet pipe and a slurry outlet pipe. The water outlet pipe is connected to the water treatment unit, and the slurry outlet pipe is connected to the collection tank.

[0016] In an optional embodiment, the sedimentation unit further includes a second sedimentation tank, which is located downstream of the first sedimentation tank, and the top of the first sedimentation tank is connected to the second sedimentation tank via a pipe.

[0017] The circulating return assembly includes a suspension pump and a return pipeline. The return pipeline is connected to the bottom of the second sedimentation tank, and the outlet pipeline of the suspension pump is connected to the descaling unit.

[0018] In an optional embodiment, the water treatment unit includes a treatment tank and a filter assembly installed in the treatment tank. The filter assembly is provided with an inlet baffle and an outlet baffle on both sides to divide the interior of the treatment tank into an inlet tank and an outlet tank. The outlet tank is connected to the heat exchange unit and the fine filtration unit through pipes.

[0019] The filtration components include magnetic filter boxes, flat bed filters, coagulation reaction beds, sand filters, or membrane filters.

[0020] In an optional embodiment, the heat exchange unit includes a heat exchanger, a cooling water tank, and a cooling tower. The heat exchanger includes a tube side and a shell side. The tube side is connected to the outlet water tank via a heat exchange water pump and heat exchange pipes. The shell side is connected to the cooling water tank and the cooling tower via a circulating cooling assembly.

[0021] In an optional embodiment, the heat exchanger is connected to a heat exchange outlet water pipe, the flushing assembly includes a flushing jet beam, and the heat exchange outlet water pipe is disposed between the heat exchanger and the flushing jet beam.

[0022] In an optional embodiment, the fine filtration unit includes an inclined plate sedimentation tank, which is connected to the effluent tank via a fine filtration inlet pump and a fine filtration inlet pipe.

[0023] The inclined plate sedimentation tank is connected to a filter press and a fine filtration water tank via pipes. The fine filtration water tank is connected to a fine filtration outlet pump via pipes. The rinsing assembly includes a rinsing jet beam, and the fine filtration outlet pump is connected to the rinsing jet beam via a fine filtration outlet pipe.

[0024] In an optional embodiment, the descaling unit includes a descaling box for allowing the metal plate to pass horizontally, with multiple jet generators respectively arranged on the upper and lower sides of the descaling box, and the bottom of the descaling box connected to the collection box through a pipe.

[0025] The collection box includes multiple funnels located at the bottom, each funnel corresponding to a jet generator. A descaling medium mixer is provided between the jet generator and the funnels. Each of the multiple descaling medium mixers is connected to the circulating water inlet pipe group and is respectively connected to the water inlet branch pipe of the circulating water inlet pipe group.

[0026] An abrasive feed pipe is provided between each of the descaling media mixers and each of the funnels. The descaling media mixer includes a Venturi mixer, which includes an abrasive inlet at the top and a water inlet and a discharge outlet on both sides. The abrasive feed pipe is connected to the abrasive inlet. A circulating water pump is connected to the water inlet and is connected to the water inlet branch pipe. The discharge outlet is connected to the jet generator through a pipe.

[0027] The outlet end of the water outlet pipe is connected to the circulating water inlet pipe assembly.

[0028] Secondly, the present invention provides a method for treating metal descaling wastewater, which is carried out using the metal descaling wastewater treatment device described in the foregoing embodiments, and includes the following steps:

[0029] The metal plate is descaled by jet in the descaling unit, and the descaling wastewater in the descaling unit is passed into the sedimentation unit for settling.

[0030] After settling, the suspension is subjected to cyclone separation and return treatment through the cyclone separation unit and the circulation return assembly. The top suspension of the cyclone separation is fed into the water treatment unit, the abrasive separated by the cyclone separation is returned to the descaling unit, and the returned suspension is returned to the descaling unit and mixed with the abrasive in the descaling unit before being circulated and sprayed for descaling.

[0031] The settled top suspension is fed into the water treatment unit, which is used to filter the received top suspension, and the resulting filter residue is discharged.

[0032] Part of the clear liquid in the water treatment unit is fed into the heat exchange unit, and the other part of the clear liquid is fed into the fine filtration unit.

[0033] The cooling water cooled by the heat exchange unit is fed into the flushing assembly to flush the surface of the descaled metal sheet.

[0034] The filtered water obtained from the fine filtration unit is fed into the rinsing assembly to rinse the surface of the washed metal plates, and the waste obtained from the fine filtration is discharged by pressure filtration.

[0035] Both the flushing water and the rinsing water are recycled back to the descaling unit for reuse in jet descaling.

[0036] The metal descaling wastewater treatment device and method of this invention can realize the recycling and reuse of descaling wastewater, maximize the reuse rate of circulating water, reduce water consumption, and avoid pollution to the environment caused by descaling wastewater.

[0037] By performing multi-stage filtration on the water produced in the descaling unit and recycling it separately, the used working fluid is filtered in different ways and used for mixing abrasives and for rinsing and washing metal parts. This maximizes the utilization of the water produced in the process and completely recovers the abrasives, thereby reducing production costs.

[0038] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the frame structure of the metal descaling wastewater treatment device in this application.

[0041] icon:

[0042] 101 - Jet generator; 109 - Descaling box;

[0043] 200 - Collection tank; 201 - Descaling media mixer; 202 - First sedimentation tank; 203 - Second sedimentation tank; 204 - Suspension pump; 205 - Hydrocyclone separator;

[0044] 301 - Filter assembly; 302 - Fine filtration inlet pump; 303 - Inclined plate sedimentation tank; 304 - Filter press;

[0045] 401-Fine filtration water tank; 402-Fine filtration outlet water pump; 403-Rinsing spray beam; 407-Cooling water tank; 408-Cooling tower; 409-Heat exchanger; 410-Scrubber spray beam; 414-Hot water pump. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0048] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] The metal descaling wastewater treatment device in this application is mainly used in the descaling process of metal plate surfaces, specifically in the treatment of descaling wastewater after removing scale from metal surfaces.

[0050] By treating the descaling wastewater, we can effectively prevent it from polluting the natural water environment, while also achieving the recycling of water and abrasive materials, ensuring the reuse rate of water and abrasive materials.

[0051] The processing device in this invention can completely recover abrasives by treating descaling wastewater at different stages. Combined with cooling the large amount of produced water consumed during the treatment process, it can reduce water evaporation and maximize the recycling rate of abrasives and water.

[0052] In the descaling process of metal sheets, a large amount of water is consumed, whether it's the mixed jet spraying process, the water rinsing of the descaled surface, or the rinsing treatment to maintain cleanliness. Meanwhile, appropriately reducing water temperature is key to minimizing water consumption, as higher temperatures lead to greater water evaporation losses. How to reasonably reduce water consumption, effectively control water temperature, and return the treated abrasive to the mixed jet spraying process are crucial for significantly improving the stability of the descaling system and reducing costs.

[0053] See Figure 1 The metal descaling wastewater treatment device of the present invention is mainly used in the abrasive and water mixed spray descaling system, especially the abrasive and water mixed spray system used for recycling and treatment of the abrasive and water mixed media. It can fully and completely recycle water and abrasive, improve the recycling rate of water and abrasive in metal surface descaling production, and reduce the risk of descaling wastewater polluting the environment.

[0054] In terms of system composition, the metal descaling wastewater treatment device of the present invention mainly includes a descaling unit, a sedimentation unit, a water treatment unit, a heat exchange unit, a fine filtration unit, and a rinsing unit.

[0055] The descaling unit mainly performs the descaling process on metal plates and generates descaling wastewater in the process. The descaling wastewater is fed into the sedimentation unit for preliminary sedimentation treatment, and some of the water and abrasive are returned to the descaling unit. The water treatment unit receives the clear liquid after the preliminary sedimentation treatment in the sedimentation unit and performs filtration treatment.

[0056] The heat exchange unit is used to cool part of the produced water from the water treatment unit and then transport the cooled produced water to the rinsing process, which has a large water consumption. The cooled produced water is used to rinse the surface of the metal plates, thereby reducing evaporation and water consumption by lowering the temperature of the rinsing water.

[0057] The fine filtration unit mainly performs fine filtration on another part of the water produced by the water treatment unit, and then sends the finely filtered water to the rinsing process for rinsing the surface of the metal plates with the clean water.

[0058] Based on the above functional perspective, the sedimentation unit is located between the descaling unit and the water treatment unit, including preliminary sedimentation and secondary sedimentation treatment. It mainly settles the descaling wastewater generated by the descaling unit and then passes it into the water treatment unit for further filtration.

[0059] To enable partial abrasive recovery, a cyclone separator is installed between the descaling and sedimentation units. This cyclone separator is connected to both the descaling and water treatment units via pipelines. Specifically, the cyclone separator treats the initial sedimentation of the bottom suspension, i.e., the initial turbid sediment. The cyclone separator separates the abrasive and the turbid sediment. The separated abrasive is primarily returned to the descaling unit for recycling. The separated turbid sediment is directly fed into the water treatment unit to mix with the clarified liquid after secondary sedimentation for further filtration.

[0060] A circulation backflow component is installed between the sedimentation unit and the descaling unit. The bottom suspension after secondary sedimentation is returned to the descaling unit as circulating water for reuse.

[0061] The heat exchange unit and the fine filtration unit are connected to the water treatment unit through pipes respectively. The flushing and rinsing unit includes a flushing component and a rinsing component. The heat exchange unit is connected to the flushing component through pipes, and the fine filtration unit is connected to the rinsing component through pipes.

[0062] Part of the filtered water from the water treatment unit is pumped to the heat exchange unit. After cooling, it is pumped to the flushing assembly to flush the surface of the metal plates. Another part of the water is pumped to the fine filtration unit for fine filtration and sedimentation. The purified water after fine filtration and sedimentation is pumped to the rinsing assembly to rinse the upper and lower surfaces of the metal plates.

[0063] The rinsing and washing unit is connected to the descaling unit via pipes to return the rinsing and washing water to the descaling unit for recycling. By returning the rinsing and washing water obtained from the rinsing and washing unit to the descaling unit, complete recycling of the circulating water and the rinsing and washing abrasive can be achieved, maximizing the reuse rate of water and abrasive.

[0064] In one specific embodiment, the sedimentation unit includes a first sedimentation tank 202 arranged sequentially, and the descaling unit includes a collection tank 200 for receiving descaling wastewater. The collection tank 200 is connected to the first sedimentation tank 202 through a pipe. The first sedimentation tank 202 receives the suspension from the collection tank 200 in the descaling unit and performs preliminary sedimentation. The bottom of the first sedimentation tank 202 is connected to a cyclone separation unit through a lift pump and a lift pipe to separate the abrasive and wastewater in the bottom suspension after preliminary sedimentation through the cyclone separation unit.

[0065] It should be noted that the descaling wastewater in the collection box 200 of the descaling unit, and the large abrasive particles, that is, reusable abrasive particles, will sink to the bottom of the collection box 200. The suspension in the upper part is a mixture of wastewater, scale, and finely crushed abrasive particles. During the treatment process, the scale and finely crushed abrasive particles are mainly removed and filtered.

[0066] The cyclone separation unit includes multiple cyclone separators 205 arranged in parallel (206-207 in the attached figure are also the same cyclone separators). Each of the cyclone separators is connected to a water outlet pipe and a slurry outlet pipe, which are used to output the separated abrasive and the separated turbid liquid after cyclone separation, respectively.

[0067] The outlet pipe is connected to the water treatment unit, through which the separated turbid liquid is further filtered to remove floating matter. The slurry outlet pipe is connected to the collection box 200, through which the separated abrasive is recycled back to the collection box for further reuse.

[0068] The sedimentation unit also includes a second sedimentation tank 203, which is located downstream of the first sedimentation tank 202. The top of the first sedimentation tank 202 is connected to the second sedimentation tank 203 through a pipe for secondary sedimentation of the clear liquid after initial sedimentation. The suspension after initial sedimentation in the first sedimentation tank 202, i.e. the suspension at the top, enters the second sedimentation tank 203 for secondary sedimentation. The top suspension after secondary sedimentation is then piped from the second sedimentation tank 203 into the water treatment unit.

[0069] After initial settling, the abrasive content in the second sedimentation tank 203 is greatly reduced. The suspension at the bottom of the second sedimentation tank 203 can be returned to the descaling unit as circulating water through the circulation return component.

[0070] The circulation return assembly includes a suspension pump 204 and a return pipe. The return pipe is connected to the bottom of the second sedimentation tank 203, and the outlet pipe of the suspension pump 204 is connected to the descaling unit.

[0071] The water treatment unit includes a treatment tank and a filter assembly 301 installed in the treatment tank. The filter assembly 301 has an inlet baffle and an outlet baffle on both sides to divide the interior of the treatment tank into an inlet tank and an outlet tank. The inlet tank is mainly used to receive the separated turbid liquid from the hydrocyclone separator 205 and the suspension from the top of the second sedimentation tank 203.

[0072] The effluent tank is connected to the heat exchange unit and the fine filtration unit through pipes. After being processed by the filter component 301, it can remove the floating scale and fine abrasive particles in the separated turbid liquid, as well as the floating scale and fine abrasive particles in the top suspension after secondary sedimentation.

[0073] From the perspective of facilitating filtration, the filter assembly 301 includes a magnetic filter box, a flat bed filter, a coagulation reaction bed, a sand filter, or a membrane filter, which can be specifically configured during operation.

[0074] The heat exchange unit includes a heat exchanger 409, a cooling water tank 407, and a cooling tower 408. The heat exchanger 409 includes a tube side and a shell side. The tube side is connected to the outlet water pool through a heat exchange water pump 414 and heat exchange pipes. The shell side is connected to the cooling water tank 407 and the cooling tower 408 respectively through a circulating cooling assembly.

[0075] Specifically, a portion of the filtered water in the water treatment unit is pumped into the tube side of the heat exchanger 409 via the heat exchange pump 414, and then discharged from the heat exchanger 409 after heat exchange with the shell side.

[0076] The shell side is mainly used to introduce refrigerant, which cools the filtered water on the tube side. Furthermore, the shell side is connected to a cooling water tank 407 and a cooling tower 408. The refrigerant is cooled by the cooling tower 408 and then passes through the cooling water tank 407. Specifically, the circulating cooling components include a cooling water pump and cooling pipes, forming an internal circulation between the shell side of the heat exchanger 409 and the cooling water tank 407 and the cooling tower 408.

[0077] The heat exchanger 409 is connected to a heat exchange outlet water pipe. The flushing assembly includes a flushing jet beam 410 (411-413 in the attached diagram are also the same flushing jet beams). The heat exchange outlet water pipe is located between the heat exchanger 409 and the flushing jet beam 410. The cooled water is mainly used to further flush the metal plate through the flushing jet beam 410 to remove residual abrasive from the metal plate during the descaling process. This process has the highest water consumption, so using cooled water for flushing minimizes water evaporation and reduces water consumption.

[0078] Meanwhile, by recycling the flushed water back to the descaling unit, the overall temperature of the descaling wastewater can be reduced, and the wastewater temperature can be kept low throughout the process, thereby ensuring that the amount of water evaporation is kept to a minimum.

[0079] The fine filtration unit includes an inclined plate sedimentation tank 303, which is connected to the effluent tank in the water treatment unit via a fine filtration inlet pump 302 and a fine filtration inlet pipe, so as to pump the filtered water in the effluent tank to the inclined plate sedimentation tank 303.

[0080] The inclined plate sedimentation tank 303 is connected to a filter press 304 and a fine filtration water tank 401 via pipes. Specifically, the filter press 304 is mainly used to filter the waste residue at the bottom of the inclined plate sedimentation tank 303, while the fine filtration water tank 401 is mainly used to receive the produced water after further water purification in the inclined plate sedimentation tank 303.

[0081] The fine filtration water tank 401 is connected to the fine filtration water pump 402 via a pipe. The rinsing assembly includes a rinsing spray beam 403 (404-406 in the attached figure are also the same rinsing spray beams). The fine filtration water pump 402 is connected to the rinsing spray beam 403 via a fine filtration water outlet pipe. It is mainly used to transport the finely filtered water, which has been further optimized, to the rinsing spray beam 403 to rinse the surface of the metal plate after rinsing. The finely filtered water has a high degree of cleanliness, which can meet the cleanliness requirements of the surface of the metal plate after rinsing.

[0082] In addition, the filter press 304 pumps the waste residue from the bottom of the inclined plate sedimentation tank 303 for filtration and pressing. After filtration, a filter cake with lower moisture content is formed, reducing water loss. The obtained filter cake is collected and treated to minimize the amount of waste from descaling wastewater and improve environmental protection requirements.

[0083] The descaling unit includes a descaling box 109 for allowing metal plates to pass horizontally. Multiple jet generators 101 (102-108 in the attached figure are also the same jet generators) are respectively arranged on the upper and lower sides of the descaling box 109. The jet descaling operation on the surface of the metal plate is mainly carried out in the descaling box 109, and descaling wastewater is generated.

[0084] The bottom of the descaling tank 109 is connected to the collection tank 200 via a pipe. Furthermore, the bottom of the descaling tank 109 is funnel-shaped, which is used to allow all the generated descaling wastewater to flow into the collection tank 200 by gravity.

[0085] The collection box 200 includes multiple funnels at the bottom for collecting all the descaling wastewater after descaling. The descaling wastewater automatically flows into the collection box 200 from the bottom of the descaling box 109 based on vertical gravity, and settles at the multiple funnel locations, causing the abrasive to settle at the funnel locations.

[0086] The funnel corresponds one-to-one with the jet generator 101. A descaling media mixer 201 is provided between the jet generator 101 and the funnel. Further, the descaling media mixer 201 mainly includes a water abrasive mixer, which is specifically used to mix circulating water and abrasive. The water abrasive mixer is connected to the collection box 200.

[0087] Furthermore, the descaling media mixer 201, the funnel, and the jet generator 101 correspond one-to-one. Multiple descaling media mixers 201 are connected to the circulating water inlet pipe group and are respectively connected to the inlet branch pipe of the circulating water inlet pipe group, so that the circulating water enters the descaling media mixer 201 through the inlet branch pipe.

[0088] An abrasive feed pipe is provided between each descaling media mixer 201 and each funnel. The descaling media mixer 201 includes a venturi mixer, which includes an abrasive inlet located at the top. The funnel is connected to the abrasive inlet through the abrasive feed pipe so that the abrasive deposited in the funnel is fed into the venturi mixer through the abrasive inlet.

[0089] The Venturi mixer also includes an inlet and an outlet located at both ends. The abrasive feed pipe is connected to the abrasive inlet, and the inlet is connected to a circulating water pump. The circulating water pump is connected to the inlet branch pipe, which is mainly used to increase the inlet flow rate of the circulating water in the Venturi mixer. Combined with the characteristics of the Venturi tube and the connection between the outlet and the jet generator 101 through the pipe, the abrasive and the circulating water are fully mixed and sprayed out at high speed, and finally delivered to the jet generator 101.

[0090] From the angle of the return flow of the circulating water at the bottom of the second sedimentation tank 203, the outlet end of the water outlet pipe is connected to the circulating water inlet pipe group, which can return the working liquid at the bottom of the second sedimentation tank 203 to the circulating water inlet pipe group, and further enter the descaling media mixer 201.

[0091] The present invention also provides a method for treating metal descaling wastewater, comprising the following steps:

[0092] The metal plates undergo jet descaling in the descaling unit, and the descaling wastewater from the descaling unit is passed into the sedimentation unit for settling.

[0093] After settling, the suspension is subjected to cyclone separation and return treatment through the cyclone separation unit and the circulation return assembly. Specifically, the sedimentation unit includes preliminary sedimentation and secondary sedimentation, respectively, performing cyclone separation on the suspension at the bottom of the preliminary sedimentation and returning the suspension at the bottom of the secondary sedimentation.

[0094] The top suspension from the cyclone separation is fed into the water treatment unit, the abrasive from the cyclone separation is returned to the descaling unit, and the returned suspension is returned to the descaling unit and mixed with the abrasive in the descaling unit before being circulated and sprayed for descaling.

[0095] The top suspension after sedimentation in the sedimentation unit is fed into the water treatment unit, which filters the received top suspension to remove scale and fine abrasive particles. The resulting filter residue is then discharged.

[0096] Part of the filtered liquid from the water treatment unit is fed into the heat exchange unit, while another part of the filtered liquid is fed into the fine filtration unit for further water quality optimization.

[0097] Cooling water from the heat exchange unit is fed into the flushing assembly to flush the surface of the descaled metal plate, removing the abrasive residue remaining on the surface of the metal plate after descaling.

[0098] The filtered water obtained from the fine filtration unit is fed into the rinsing assembly to rinse and clean the surface of the metal plate after rinsing. The waste obtained from fine filtration is then discharged through a filter press.

[0099] Both the flushing water and the rinsing water are recycled back to the descaling unit, specifically to the collection box 200 in the descaling unit, for reuse in jet descaling.

[0100] In this invention, the metal surface descaling system typically involves mixing hard particles with a high-speed water flow and then flushing the metal plate to remove the scale from the metal surface. The abrasive mixture after cleaning, which includes both hard abrasives and a large amount of water, needs to be recycled. The unusable sludge, containing unusable hard abrasives and scale, undergoes contaminant treatment.

[0101] The descaling chamber 109 contains eight jet generators 101. Metal plates move from right to left, passing through the middle of the jet generators 101 for descaling. The metal plates are typically flat metal sheets. The descaling wastewater, after being flushed by a mixture of water and abrasive, flows into the bottom of the descaling chamber 109. During the flushing process, water is continuously used to flush the metal plates, washing away the abrasive particles impacting the surface of the metal plates to improve the descaling effect. Simultaneously, the high-speed impact of the abrasive particles from the jet generators 101 on the metal plates during descaling results in relatively high water temperatures, sometimes reaching 70-80°C. To improve system stability, reduce water evaporation, and prevent injury from hot water, the water temperature needs to be lowered.

[0102] The water used for rinsing in the descaling unit requires a large amount of treated recycled water to achieve environmental protection and cost reduction. This water can be recycled back from the subsequent rinsing unit. The descaled metal plates also need to be cleaned by rinsing with water of high purity to complete the descaling process.

[0103] Due to vertical gravity, all descaling water, abrasive particles, and scale are discharged from the descaling tank 109 into the collection tank 200. Larger, reusable abrasive particles sink to the bottom, while the upper suspension is a mixture of water, scale, and finely pulverized abrasive particles. The bottom of the collection tank 200 has several funnels corresponding to the number of jet generators 101. The settled abrasive particles enter the lower descaling media mixer 201, which is essentially a Venturi mixer—a mixer for water and abrasive particles—and the flow rate can be controlled. The other inlet of the Venturi mixer is a water inlet. After mixing in the Venturi mixer, the abrasive and water are pumped separately into the jet generators 101 for reuse. Here, the Venturi mixer is used to mix abrasive and water, and in conjunction with the circulating water pump, it also has a pumping function; other mixing methods can also be used.

[0104] The suspension containing impurities such as scales at the top of the collection tank 200 flows into the first sedimentation tank 202 via physical overflow. After initial settling, the suspension at the top of the first sedimentation tank 202 overflows into the second sedimentation tank 203. The abrasive and water mixture slurry at the bottom of the first sedimentation tank 202 is transported to the hydrocyclone separator 205 via a lift pump and lift pipeline for further separation of the abrasive, improving the recycling rate of the abrasive. The lift pump can be a slurry pump. The three pumps in the attached diagram are in a two-operated-one-standby configuration; the number of pumps is determined based on the workload.

[0105] The hydrocyclone separator 205 receives the slurry containing abrasive particles from the bottom of the first sedimentation tank 202, which is delivered by the booster pump, and performs hydrocyclone separation. The usable abrasive particles are transported to the collection tank 200 for recycling, while the wastewater containing impurities such as scales is transported to the downstream water treatment unit for treatment.

[0106] The wastewater in the upper part of the second sedimentation tank 203 flows into the water treatment unit, while the relatively clear water at the bottom is transported to the descaling unit through the suspension pump 204 and the return pipe. Specifically, it is transported to the circulating water inlet pipe group of the descaling media mixer 201, and then further mixed with abrasive in the descaling media mixer 201 before being sent to the jet generator 101. This is the first recycling of water, which can be relatively turbid water.

[0107] The water treatment unit can be a magnetic filter box, a flat bed filter, a coagulation reaction bed, a sand filter or a membrane filter, etc., to further filter the suspension at the top of the second sedimentation tank 203. Part of the filtered water is pumped to the heat exchanger 409 through the heat exchange pump 414 and heat exchange pipeline.

[0108] The shell-side passage of heat exchanger 409 is a cooling water tank 407 and a cooling tower 408. This passage provides refrigerant to heat exchanger 409 to cool the water filtered by the incoming water treatment unit.

[0109] After cooling, the water can be used to rinse the surface of downstream metal plates. The water temperature from heat exchanger 409 is reduced to normal water temperature and then transported to the rinsing jet beam 410 to rinse the metal plate. This rinses away the abrasive residue generated by the jet generator 101 during the descaling stage. The residue generated by the jet will greatly reduce the descaling effect, so it is necessary to remove the residue from the metal plate by rinsing. At the same time, the abrasive is recycled and reused.

[0110] Since the water required for rinsing accounts for the largest proportion in the descaling device, it is only necessary to cool the water required for rinsing and then circulate and mix it to basically achieve the cooling of the circulating water in the entire system.

[0111] Another portion of the water from the water treatment unit is boosted by the fine filtration inlet pump 302 and sent to the inclined plate sedimentation tank 303 of the fine filtration unit for further water purification. The waste residue after sedimentation in the inclined plate sedimentation tank 303 is pumped to the filter press 304 for treatment. The relatively clean water at the top of the inclined plate sedimentation tank 303 is pumped to the fine filtration water tank 401. The clean water in the fine filtration water tank 401 is boosted by the fine filtration outlet pump 402 and sent to the rinsing jet beam 403 to rinse the metal plate after it has been treated by the jet generator 101 and rinsed, removing the abrasive residue attached to the metal plate.

[0112] In summary, the working fluid of the jet generator 101 mainly consists of water and abrasive. Water is used in very large quantities, and the cost of abrasive is relatively high, both requiring recycling. After the jet descaling process, the liquid in the treated fluid includes not only the abrasive and water that need to be recycled, but also metal surface scale and unusable fragments from broken abrasive. This waste needs to be removed to allow for the recycling of the abrasive and water.

[0113] The recycling of abrasives begins with sedimentation in the collection tank 200. Larger abrasive particles, meaning those with minimal breakage, are then pumped to a Venturi mixer to mix with the circulating return water before being pumped to the jet generator 101 for recycling. Secondly, some abrasive particles in the suspension at the top of the collection tank 200 still meet the jet descaling standards. After initial settling in the first sedimentation tank 202, these particles are screened by a hydrocyclone separator 205 and then transported back to the collection tank 200 for further sedimentation and reuse. This improves the reusability of the abrasives, increases efficiency, and reduces costs.

[0114] Water recycling is crucial in the recycling of working fluids, as the volume of water used is enormous, and both economic and environmental standards must be met. In this application, water is recycled separately according to the different water purity requirements in different work processes, which greatly reduces costs and improves the water recycling rate.

[0115] First, after the suspension is settled and filtered in the second sedimentation tank 203, the water after sedimentation is not very pure, but it can meet the requirements of the working fluid medium of the jet generator 101. Therefore, this part of the settled water can be pumped to the Venturi mixer to be mixed with the abrasive and then transported to the jet generator 101 for use.

[0116] Secondly, the wastewater after removing the abrasive is treated by the water treatment unit and can be used to rinse the metal plates. The main process here is that the metal plates must be rinsed with water after each jet impact to remove abrasive residue and meet the jet requirements. In addition, the high-temperature water generated by the jet also needs to be cooled down. A portion of the water treated by the water treatment unit, which accounts for a large portion of the circulating water, is boosted by the hot water pump 414 and sent to the heat exchanger 409. The refrigerant passage of the heat exchanger 409 consists of the cooling tower 408, the cooling water tank 407, and the shell-side passage of the heat exchanger 409 to cool the water flowing through the heat exchanger 409. Then, it is sent to the rinsing jet beam 410 to rinse the metal plates and clean the abrasive residue on the surface of the metal plates.

[0117] Finally, the water treated by the water treatment unit is purified in the inclined plate sedimentation tank 303, and then transported to the rinsing spray beam 403 through the fine filter water tank 401 and the fine filter outlet water pump 402 to rinse the metal plate, completing the final cleaning of the metal plate. Finally, the rinsing water and the rinsing water are returned to the collection tank 200.

[0118] After the above recycling of abrasive and water, the waste in the inclined plate sedimentation tank 303 is then collected and treated by the filter press 304. This method results in the least amount of waste and is the most environmentally friendly.

[0119] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0120] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A metal descaling wastewater treatment device, characterized in that, include: Descaling unit, sedimentation unit, water treatment unit, heat exchange unit, fine filtration unit, and rinsing unit; The sedimentation unit is located between the descaling unit and the water treatment unit. A cyclone separation unit is located between the descaling unit and the sedimentation unit. The cyclone separation unit is connected to the descaling unit and the water treatment unit respectively through pipelines. A circulation backflow assembly is provided between the sedimentation unit and the descaling unit; The heat exchange unit and the fine filtration unit are respectively connected to the water treatment unit through pipes, and the flushing and rinsing unit includes a flushing component and a rinsing component. The heat exchange unit is connected to the flushing assembly via a pipe, and the fine filtration unit is connected to the rinsing assembly via a pipe; The rinsing and washing unit is connected to the descaling unit via a pipe to return the rinsing and washing water to the descaling unit for recycling. The water treatment unit includes a treatment tank and a filter assembly installed in the treatment tank. The filter assembly is provided with an inlet baffle and an outlet baffle on both sides to divide the interior of the treatment tank into an inlet tank and an outlet tank. The outlet tank is connected to the heat exchange unit and the fine filtration unit through pipes. The filtration assembly includes a magnetic filter box, a flat bed filter, a coagulation reaction bed, a sand filter, or a membrane filter; The heat exchange unit includes a heat exchanger, a cooling water tank, and a cooling tower. The heat exchanger includes a tube side and a shell side. The tube side is connected to the outlet water tank through a heat exchange water pump and heat exchange pipes. The shell side is connected to the cooling water tank and the cooling tower respectively through a circulating cooling assembly. The fine filtration unit includes an inclined plate sedimentation tank, which is connected to the effluent tank via a fine filtration inlet pump and a fine filtration inlet pipe. The inclined plate sedimentation tank is connected to a filter press and a fine filtration water tank via pipes. The fine filtration water tank is connected to a fine filtration water pump via pipes. The rinsing assembly includes a rinsing jet beam. The fine filtration water pump is connected to the rinsing jet beam via a fine filtration water outlet pipe. The sedimentation unit includes a first sedimentation tank, and the descaling unit includes a collection tank for receiving descaling wastewater. The collection tank is connected to the first sedimentation tank via a pipe, and the bottom of the first sedimentation tank is connected to the cyclone separation unit via a lift pump and a lift pipe. The cyclone separation unit includes multiple cyclone separators arranged in parallel. Each cyclone separator is connected to a water outlet pipe and a slurry outlet pipe. The water outlet pipe is connected to the water treatment unit, and the slurry outlet pipe is connected to the collection tank. The sedimentation unit further includes a second sedimentation tank, which is located downstream of the first sedimentation tank. The top of the first sedimentation tank is connected to the second sedimentation tank via a pipe. The top suspension after secondary sedimentation is fed into the water treatment unit through a pipe from the second sedimentation tank. The circulating return assembly includes a suspension pump and a return pipeline. The return pipeline is connected to the bottom of the second sedimentation tank, and the outlet pipeline of the suspension pump is connected to the descaling unit.

2. The metal descaling wastewater treatment apparatus according to claim 1, characterized by The heat exchanger is connected to a heat exchange outlet water pipe, and the flushing assembly includes a flushing jet beam. The heat exchange outlet water pipe is disposed between the heat exchanger and the flushing jet beam.

3. The metal descaling wastewater treatment apparatus according to claim 1, characterized by The descaling unit includes a descaling box for allowing metal plates to pass horizontally. Multiple jet generators are respectively arranged on the upper and lower sides of the descaling box, and the bottom of the descaling box is connected to the collection box through a pipe. The collection box includes multiple funnels located at the bottom, each funnel corresponding to a jet generator. A descaling medium mixer is provided between the jet generator and the funnels, and the multiple descaling medium mixers are respectively connected to the inlet branch pipes of the circulating water inlet pipe group. An abrasive feed pipe is provided between each of the descaling media mixers and each of the funnels. The descaling media mixer includes a Venturi mixer, which includes an abrasive inlet at the top and a water inlet and a discharge outlet on both sides. The abrasive feed pipe is connected to the abrasive inlet. A circulating water pump is connected to the water inlet and is connected to the water inlet branch pipe. The discharge outlet is connected to the jet generator through a pipe. The outlet end of the suspension pump's outlet pipe is connected to the circulating water inlet pipe assembly.

4. A method for treating metal descaling wastewater, characterized by using the metal descaling wastewater treatment device according to claim 1. Includes the following steps: Metal plates are descaled by jet in the descaling unit, and the descaling wastewater in the descaling unit is fed into the first sedimentation tank of the sedimentation unit for the first sedimentation; the top suspension generated by the first sedimentation is fed into the second sedimentation tank for the second sedimentation. The bottom suspension generated during the first settling is separated by a cyclone separation unit. The separated turbid liquid generated by the cyclone separation is fed into the water treatment unit, and the separated abrasive material generated by the cyclone separation is returned to the descaling unit. The bottom suspension generated during the second settling is directly returned to the descaling unit through a circulation return assembly, where it is mixed with the abrasive material and then circulated for descaling. The turbid liquid produced by the hydrocyclone separation and the top suspension produced by the second sedimentation are jointly fed into the water treatment unit for filtration, and the filter residue is discharged externally. A portion of the clear liquid in the water treatment unit is fed into the heat exchange unit, and another portion of the clear liquid is fed into the fine filtration unit. The cooling water cooled by the heat exchange unit is fed into the flushing assembly to flush the surface of the descaled metal sheet. The filtered water obtained from the fine filtration unit is fed into the rinsing assembly to rinse the surface of the washed metal plates, and the waste obtained from the fine filtration is discharged by pressure filtration. Both the flushing water and the rinsing water are recycled back to the descaling unit for reuse in jet descaling.

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