Metal descaling wastewater treatment device and treatment method

Abstract

The invention relates to a metal descaling wastewater treatment device and method, and the metal descaling wastewater treatment device comprises a descaling unit, a precipitation unit, a water treatment unit, a heat exchange unit, a fine filtration unit and a washing and rinsing unit; a cyclone separation unit is arranged between the scaling unit and the precipitation unit and is respectively connected with the scaling unit and the water treatment unit through pipelines; the heat exchange unit and the fine filtration unit are respectively connected with the water treatment unit through pipelines, and the washing and rinsing unit comprises a washing assembly and a rinsing assembly; the heat exchange unit is connected with the flushing assembly through a pipeline, and the fine filtration unit is connected with the rinsing assembly through a pipeline; and the washing and rinsing unit is connected with the scaling unit through a pipeline and is used for discharging washing and rinsing water back to the scaling unit for recycling. The pollution of the descaling wastewater to the environment can be reduced. According to the invention, the recycling rate of water and abrasive materials can be effectively improved, pollution treatment of the descaling wastewater is realized, and pollution of the descaling wastewater to the environment is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of water pollution control, and in particular to a metal descaling wastewater treatment device and a treatment method. Background Art

[0002] In the process of rolling and forming metal materials, especially in the production of hot-rolled metal flat plates or coils, the metal slab will oxidize when heated in the heating furnace, forming a layer of substance called oxide scale, which mainly includes primary oxide scale and secondary oxide scale. Because there are dense cracks on the surface after cooling, it looks like fish scales, so 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 metal product, but will also accelerate the wear of the rollers, thereby affecting production efficiency and product quality.

[0004] The mixed jet descaling technology uses a water jet to drive tiny hard particles, collectively known as abrasives, which can also be called media. After the hard particles are accelerated to a sufficiently high speed by the water jet as a carrier, they are flushed and bombarded toward the target object, thereby achieving effective cleaning of corrosion layers on the surface of various products such as rust layers, scales, paint layers, and burrs on corners.

[0005] Abrasives are expensive and the amount of water used is huge. Both abrasives and water need to be recycled. In the actual mixed jet descaling production, if the medium produced after descaling cannot be recycled, the water consumption will become very huge.

[0006] In addition, the wastewater in the descaling medium contains pollutants such as stripped iron oxide, oil, suspended matter, and possibly 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 treatment method, which can effectively improve the recycling rate of water and abrasives in the metal dephosphorization medium, and realize the pollution treatment of descaling wastewater, and reduce the pollution caused by descaling wastewater to the environment.

[0008] In order to achieve the above-mentioned object, 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 flushing and rinsing unit;

[0009] The sedimentation unit is arranged between the descaling unit and the water treatment unit, a cyclone separation unit is arranged between the descaling unit and the sedimentation unit, and the cyclone separation unit is respectively connected to the descaling unit and the water treatment unit through pipelines;

[0010] A circulation backflow component is provided between the precipitation unit and the descaling unit;

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

[0012] The heat exchange unit is connected to the flushing component through a pipeline, and the fine filtration unit is connected to the rinsing component through a pipeline;

[0013] The flushing and rinsing unit is connected to the descaling unit through a pipeline, so as to return the flushing and rinsing water to the descaling unit for recycling.

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

[0015] In an optional embodiment, the cyclone separation unit includes a plurality of cyclone separators arranged in parallel, each of the cyclone separators is respectively 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 box.

[0016] In an optional embodiment, the sedimentation unit further includes a second sedimentation tank, which is arranged downstream of the first sedimentation tank, and the top of the first sedimentation tank is connected to the second sedimentation tank through a pipeline;

[0017] The circulation backflow component comprises a suspension pump and a backflow pipe, the backflow pipe is connected to the bottom of the second sedimentation tank, and the outlet pipe 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, and a water inlet baffle and a water outlet baffle are respectively provided on both sides of the filter assembly to separate the interior of the treatment tank into an inlet tank and an outlet tank, and the outlet tank is respectively connected to the heat exchange unit and the fine filtration unit through pipelines;

[0019] The filter assembly includes a magnetic filter box, a flat bed filter, a coagulation reaction bed, a sand filter or a membrane filter.

[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 water outlet pool through a heat exchange water pump and a heat exchange pipe, and the shell side is respectively connected to the cooling water tank and the cooling tower through a circulating cooling component.

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

[0022] In an optional embodiment, the fine filtration unit includes an inclined plate sedimentation tank, and the inclined plate sedimentation tank is connected to the water outlet tank through a fine filtration water inlet pump and a fine filtration water inlet pipeline;

[0023] The inclined plate sedimentation tank is connected to a filter press and a fine filter water tank through pipelines, the fine filter water tank is connected to a fine filter water pump through pipelines, the rinsing component includes a rinsing spray beam, and the fine filter water pump is connected to the rinsing spray beam through a fine filter water outlet pipeline.

[0024] In an optional embodiment, the descaling unit includes a descaling box for allowing the metal plate to pass horizontally, a plurality of 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 collecting box through a pipeline;

[0025] The collecting box includes a plurality of funnels at the bottom, the funnels correspond to the jet generators one by one, a descaling medium mixer is arranged between the jet generator and the funnel, and the plurality of descaling medium mixers are all connected to the circulating water inlet pipe group and are respectively connected to the water inlet branch pipes of the circulating water inlet pipe group;

[0026] An abrasive feed pipeline is provided between each of the descaling medium mixers and each of the funnels, the descaling medium mixer comprises a Venturi mixer, the Venturi mixer comprises an abrasive inlet located at the top, and a water inlet and a material outlet respectively located at both sides, the abrasive feed pipeline is connected to the abrasive inlet, the water inlet is connected to a circulating water inlet pump, the circulating water inlet pump is connected to the water inlet branch pipe, and the material outlet is connected to the jet generator through a pipeline;

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

[0028] In a second aspect, the present invention provides a method for treating metal descaling wastewater, which is carried out by the metal descaling wastewater treatment device described in the above embodiment, comprising the following steps:

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

[0030] The suspended liquid after sedimentation is subjected to cyclone separation and backflow treatment respectively through the cyclone separation unit and the circulation backflow component, the top suspended liquid of the cyclone separation is introduced into the water treatment unit, the abrasive of the cyclone separation is returned to the descaling unit, and the backflow suspended liquid is returned to the descaling unit and mixed with the abrasive in the descaling unit and then circulated and sprayed for descaling;

[0031] The top suspension after settling is passed into the water treatment unit, and the water treatment unit is used to filter the received top suspension, and the obtained filter residue is discharged;

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

[0033] The cooling water after cooling of the heat exchange unit is passed into the flushing component to flush the surface of the metal plate after descaling;

[0034] The fine filtration water obtained by the fine filtration unit is passed into the rinsing component to rinse the surface of the metal plate after flushing, and the waste obtained by the fine filtration is filtered out by pressure;

[0035] The flushing water and the rinsing water are circulated back to the descaling unit to be reused in the jet descaling.

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

[0037] By multi-stage filtering the water produced in the descaling device, the water is recycled separately. The used working fluid is filtered differently and used as water-abrasive mixing, as well as for flushing and rinsing metal parts. The water produced in the treatment process is utilized to the greatest extent, and the abrasive is completely recovered, thereby reducing production costs.

[0038] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

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

[0041] icon:

[0042] 101-jet generator; 109-descaling box;

[0043] 200-collecting box; 201-de-scaling medium mixer; 202-first sedimentation tank; 203-second sedimentation tank; 204-suspension pump; 205-cyclone separator;

[0044] 301-filter assembly; 302-fine filter water inlet pump; 303-inclined plate sedimentation tank; 304-filter press;

[0045] 401-fine filter water tank; 402-fine filter water pump; 403-rinsing spray beam; 407-cooling water tank; 408-cooling tower; 409-heat exchanger; 410-flushing spray beam; 414-heat exchange water pump. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0048] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] The metal descaling wastewater treatment device in the present application is mainly used in the descaling process of the metal plate surface, and is specifically used in the treatment process of descaling wastewater after removing the scales on the metal surface.

[0050] By treating the descaling wastewater, it is possible to effectively avoid its pollution to the natural water environment, while achieving the recycling of water and abrasives to ensure the reuse rate of water and abrasives.

[0051] The treatment device in the present invention can completely recover the abrasive by targeted treatment of the descaling wastewater at different stages. Combined with cooling the water produced in large consumption during the treatment process, it can reduce the evaporation of water and ensure the recovery rate of abrasive and water to the greatest extent.

[0052] In the process of descaling the surface of metal sheets, whether it is the descaling process of mixed jet injection, or the water flushing of the descaling surface, and the rinsing treatment to keep it clean, a large amount of water medium is required. At the same time, reasonably lowering the water temperature is the key to reducing water consumption, because the higher the temperature, the greater the evaporation loss of water. How to reasonably reduce water consumption, effectively control the water temperature, and return the treated abrasive to the mixed jet injection in the production process of metal surface descaling are the keys to significantly improve the stability of the descaling system and reduce costs.

[0053] See also Figure 1 The metal descaling wastewater treatment device of the present invention is mainly used in the mixed spray descaling system of abrasive and water, and in particular relates to a recovery and treatment device for the used abrasive and water mixed medium of the mixed spray system of abrasive and water, which can fully and completely recycle water and abrasive, improve the recycling rate of water and abrasive in the metal surface descaling production, and reduce the risk of descaling wastewater causing pollution to the environment.

[0054] From the perspective of system composition, the metal descaling wastewater treatment device in 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 flushing and rinsing unit;

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

[0056] The heat exchange unit is used to cool part of the produced water of the water treatment unit, and transport the cooled produced water to the flushing process with large water consumption. It is used to flush the surface of the metal plate with the cooled produced water, so as to reduce the evaporation of the flushing water by lowering its temperature and reduce water consumption.

[0057] The fine filtration unit mainly finely filters another part of the water produced by the water treatment unit, and transmits the finely filtered water to the rinsing process for rinsing the surface of the metal plate with the finely filtered water with higher cleanliness.

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

[0059] In order to realize the return and recovery of part of the abrasive, a cyclone separation unit is arranged between the descaling unit and the sedimentation unit. The cyclone separation unit is connected to the descaling unit and the water treatment unit through pipelines. Specifically, the cyclone separation unit is mainly used to treat the bottom suspension of the initial sedimentation, that is, the initial sedimentation turbid liquid, and obtain the separated abrasive and the separated turbid liquid respectively through the cyclone separation unit. The separated abrasive is mainly returned to the descaling unit for recycling and reuse. The separated turbid liquid is directly transported to the water treatment unit to be mixed with the clear liquid after the secondary sedimentation for further filtration treatment.

[0060] A circulation return assembly is arranged between the sedimentation unit and the descaling unit, through which the bottom suspension after the secondary sedimentation is returned to the descaling unit for reuse as circulating water.

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

[0062] Part of the filtered water obtained from the water treatment unit is pumped to the heat exchange unit, and after cooling treatment, it is pumped to the flushing component to flush the surface of the metal plate; the other part of the water is pumped to the fine filtration unit for fine filtration and sedimentation. The clean water after fine filtration and sedimentation is pumped to the rinsing component for rinsing the upper and lower surfaces of the metal plate.

[0063] The flushing and rinsing unit is connected to the descaling unit through a pipeline to return the flushing and rinsing water to the descaling unit for recycling. By returning the flushing and rinsing water obtained from the flushing and rinsing unit to the descaling unit, the circulating water and the flushing and rinsing abrasive can be fully circulated, thereby maximizing the reuse rate of water and abrasive.

[0064] In one specific embodiment, the sedimentation unit includes a first sedimentation tank 202 arranged in sequence, the descaling unit includes a collecting box 200 for receiving descaling wastewater, the collecting box 200 is connected to the first sedimentation tank 202 through a pipeline, the first sedimentation tank 202 receives the suspension in the collecting box 200 in the descaling unit, and performs preliminary sedimentation, and the bottom of the first sedimentation tank 202 is connected to the cyclone separation unit through a lifting pump and a lifting pipe, so as to separate the abrasive and wastewater from 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-particle abrasive, that is, the reusable abrasive will sink to the bottom of the collection box 200, and the upper suspension is a mixture of wastewater, scales and crushed fine abrasives. During the processing, the scales and the crushed fine abrasives are mainly removed and filtered.

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

[0067] The water outlet pipe is connected to the water treatment unit, and the separated turbid liquid is passed into the water treatment unit for further filtration to remove floating objects. The slurry outlet pipe is connected to the collection box 200, and the separated abrasive is circulated back to the mobile phone box for further reuse.

[0068] The sedimentation unit also includes a second sedimentation tank 203, which is arranged 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 pipeline to carry out secondary sedimentation of the clear liquid after the initial sedimentation. The suspension after the initial sedimentation of the first sedimentation tank 202, that is, the suspension at the top, enters the second sedimentation tank 203 for secondary sedimentation. The top suspension after the secondary sedimentation is passed from the second sedimentation tank 203 to the water treatment unit through a pipeline.

[0069] After the initial sedimentation, the abrasive content in the second sedimentation tank 203 is greatly reduced, and 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 backflow component includes a suspension pump 204 and a backflow pipe. The backflow pipe is connected to the bottom of the second sedimentation tank 203. 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. An inlet baffle and an outlet baffle are respectively arranged on both sides of the filter assembly 301 to separate 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 cyclone separator 205 and the suspended liquid at the top of the second sedimentation tank 203.

[0072] The outlet pool is connected to the heat exchange unit and the fine filtration unit through pipelines. After being processed by the filter component 301, the floating scales and fine abrasive particles in the separated turbid liquid and the floating scales and fine abrasive particles in the top suspension after secondary sedimentation can be filtered out.

[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 water outlet pool through a heat exchange water pump 414 and a heat exchange pipe, and the shell side is connected to the cooling water tank 407 and the cooling tower 408 respectively through a circulating cooling component.

[0075] Specifically, part of the filtered water in the water treatment unit is pumped into the tube side of the heat exchanger 409 by the heat exchange water pump 414 to increase the pressure, and is discharged from the heat exchanger 409 after heat exchange with the shell side.

[0076] The shell side is mainly used for introducing refrigerant, and the filtered water produced on the tube side is cooled by the refrigerant. 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 component includes a cooling water pump and a cooling pipe, which constitute 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 water outlet pipe, and the flushing assembly includes a flushing spray beam 410 (411-413 in the attached figure are also the same flushing spray beams), and the heat exchange water outlet pipe is arranged between the heat exchanger 409 and the flushing spray beam 410. The cooled cooling water is mainly used to further flush the metal plate through the flushing spray beam 410 to flush and remove the residual abrasive on the metal plate in the descaling process. In this process, the water consumption is the largest, so the cooled water is used for flushing to minimize the evaporation of water and reduce the water consumption.

[0078] At the same time, by recycling the flushing water back to the descaling unit, the overall temperature of the descaling wastewater can be reduced, and the descaling wastewater can be kept at a low water temperature in the overall process to ensure that the water evaporation is controlled at the lowest level.

[0079] The fine filtration unit includes an inclined plate sedimentation tank 303 , which is connected to the outlet tank in the water treatment unit through a fine filtration inlet pump 302 and a fine filtration inlet pipeline to pump the filtered water in the outlet tank to the inclined plate sedimentation tank 303 .

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

[0081] The fine filter water tank 401 is connected to the fine filter water outlet pump 402 through a pipeline, and the rinsing component includes a rinsing spray beam 403 (404-406 in the attached figure are also the same rinsing spray beams). The fine filter water outlet pump 402 is connected to the rinsing spray beam 403 through a fine filter water outlet pipeline, and is mainly used to transport the fine filter water with further optimized water quality to the rinsing spray beam 403 to rinse the surface of the metal plate after flushing. The fine filter water has a high degree of cleanliness and can meet the cleanliness requirements of the metal plate surface after rinsing.

[0082] In addition, the filter press 304 pumps the waste residue at the bottom of the inclined plate sedimentation tank 303 to filter the water and compact it. After filtering, a filter cake with a lower water content is formed to reduce water loss. The obtained filter cake is collected and processed to minimize the waste volume of descaling wastewater and improve environmental protection requirements.

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

[0084] The bottom of the descaling box 109 is connected to the collecting box 200 through a pipeline. Furthermore, the bottom of the descaling box 109 is funnel-shaped, which is used to allow all the generated descaling wastewater to flow into the collecting box 200 by gravity.

[0085] The collecting box 200 includes a plurality of funnels at the bottom for collecting all descaling wastewater after descaling. The descaling wastewater automatically flows from the bottom of the descaling box 109 into the collecting box 200 due to vertical gravity, and settles in a plurality of funnel positions, so that the abrasive settles in the funnel positions.

[0086] The funnel corresponds to the jet generator 101 one by one, and a descaling medium mixer 201 is arranged between the jet generator 101 and the funnel. Furthermore, the descaling medium mixer 201 mainly includes a water-abrasive mixer, which is specifically used to mix circulating water and abrasive, and the water-abrasive mixer is connected to the collection box 200.

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

[0088] An abrasive feed pipe is arranged between each descaling medium mixer 201 and each funnel. The descaling medium mixer 201 includes a Venturi mixer. The Venturi mixer 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 passes into the Venturi mixer through the abrasive inlet.

[0089] The venturi mixer also includes a water inlet and a discharge port respectively located at the two side ends. The abrasive feed pipeline is connected to the abrasive inlet. The water inlet is connected to a circulating water inlet pump. The circulating water inlet pump is connected to the water inlet branch pipe, which is mainly used to increase the water inlet flow rate of the circulating water in the venturi mixer. Combined with the characteristics of the venturi tube and the connection between the discharge port and the jet generator 101 through the pipeline, the abrasive and the circulating water are fully mixed and ejected at a high speed, and finally transported to the jet generator 101.

[0090] From the perspective of the return of the circulating water at the bottom of the second sedimentation tank 203 , the outlet end of the outlet pipe is connected to the circulating water inlet pipe group, so that the working fluid at the bottom of the second sedimentation tank 203 can be returned to the circulating water inlet pipe group and further enter the descaling medium mixer 201 .

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

[0092] The metal sheet is jet descaled in the descaling unit, and the descaling wastewater in the descaling unit is introduced into the sedimentation unit for sedimentation.

[0093] The suspended liquid after sedimentation is subjected to cyclone separation and backflow treatment respectively through the cyclone separation unit and the circulation backflow component. Specifically, the sedimentation unit includes primary sedimentation and secondary sedimentation. The suspended liquid at the bottom of the primary sedimentation is subjected to cyclone separation and the suspended liquid at the bottom of the secondary sedimentation is backflowed.

[0094] The top suspension of cyclone separation is introduced into the water treatment unit, the abrasive separated by cyclone is returned to the descaling unit, and the backflow suspension is returned to the descaling unit and mixed with the abrasive in the descaling unit and then circulated and sprayed for descaling.

[0095] The top suspension after sedimentation in the sedimentation unit is passed into the water treatment unit, and the water treatment unit is used to filter the received top suspension, filter the scales and fine abrasive particles in the top suspension, and discharge the obtained filter residue.

[0096] Part of the filtered clear liquid in the water treatment unit is passed into the heat exchange unit, and another part of the filtered clear liquid is passed into the fine filtration unit for further water quality optimization treatment.

[0097] The cooling water after cooling the heat exchange unit is passed into the flushing component to flush the surface of the descaled metal plate, and the abrasive remaining on the surface of the metal plate after descaling is flushed away.

[0098] The fine filtration product water obtained by the fine filtration unit is passed into the rinsing component to rinse the surface of the metal plate after flushing, clean the surface of the metal plate, and the waste obtained by the fine filtration is filtered out.

[0099] The flushing water and the rinsing water are circulated back to the descaling unit, specifically to the collecting box 200 in the descaling unit, to be reused in the jet descaling.

[0100] In the present invention, the metal surface descaling system is generally a system in which hard particles are mixed with a high-speed water flow and then flushed against a metal plate, thereby cleaning the scales on the metal surface. The abrasive mixture after cleaning includes both hard abrasives and a large amount of water, which need to be recycled, and the unusable sewage slurry containing unusable hard abrasives and scales is subjected to pollutant treatment.

[0101] The descaling box 109 has 8 jet generators 101 built in. The metal plate moves from right to left and passes through the middle of the jet generator 101 for descaling and flushing. The metal plate is generally a metal flat plate. The descaling wastewater after flushing with a mixture of water and abrasives flows into the bottom of the descaling box 109. During the flushing process, it is necessary to continuously flush the metal plate with water to flush the abrasives that impact the surface of the metal plate to improve the descaling effect. At the same time, during the descaling process, the abrasives of the jet generator 101 impact the metal plate at high speed, and the water temperature will be relatively high, even reaching about 70-80°C. In order to improve the stability of the system, reduce water evaporation, and avoid high-temperature water from hurting people, the water temperature needs to be lowered.

[0102] The water used for flushing in the descaling unit requires a large amount of treated circulating water to achieve environmental protection and reduce costs. This part of the water can be recycled by recycling the water in the subsequent flushing and rinsing units. The metal plates after descaling also need to be cleaned and rinsed with water with a higher degree of cleanliness to complete the descaling of the metal.

[0103] Based on the vertical gravity, the descaling water, abrasive, scale skin, etc., all enter the collection box 200 through the descaling box 109 through the discharge mode. Among them, the abrasive with large particles, that is, the abrasive that can be reused, will sink to the bottom, and the upper suspension is a mixture of water, scale skin and fine abrasive after crushing. The bottom of the collection box 200 is provided with a number of funnels, corresponding to the number of jet generators 101. The precipitated abrasive enters the descaling medium mixer 201 at the bottom. The descaling medium mixer 201 is specifically a Venturi mixer. Frankly speaking, it is a mixer of water and abrasive, and the flow rate can be controlled. The other inlet of the Venturi mixer is the water inlet. After the abrasive and water are mixed in the Venturi mixer, they are pumped into the jet generator 101 respectively for reuse. Here, the Venturi mixer is used to mix the abrasive and water. At the same time, it has the function of pumping in combination with the circulating water inlet pump. Other methods can also be used to achieve mixing.

[0104] The suspension with impurities such as scales on the top of the collection box 200 enters the first sedimentation tank 202 by physical overflow. After initial sedimentation, the suspension on the top of the first sedimentation tank 202 overflows to the second sedimentation tank 203. The slurry mixed with abrasive and water at the bottom of the first sedimentation tank 202 is transported to the cyclone separator 205 through the lifting pump and the lifting pipeline, which can further separate the abrasive and improve the recycling rate of the abrasive. The lifting pump can be a slurry pump. The three pumps in the figure are in a two-on and one-off state. The number of pumps is set according to the workload.

[0105] The cyclone separator 205 receives the slurry including abrasives at the bottom of the first sedimentation tank 202 delivered by the lifting pump and performs cyclone separation. The usable abrasives are delivered to the collection box 200 for recycling, and the wastewater including impurities such as scales is delivered to the downstream water treatment unit for treatment.

[0106] The sewage in the upper part of the second sedimentation tank 203 flows into the water treatment unit, and the relatively clear water at the bottom is transported to the descaling unit through the suspension pump 204 and the return pipe, specifically to the circulating water inlet pipe group of the descaling medium mixer 201, and further mixed with the abrasive through the descaling medium mixer 201 and 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 top suspension of the second sedimentation tank 203, and a part of the filtered water is pumped to the heat exchanger 409 through the heat exchange water pump 414 and the heat exchange pipe.

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

[0109] The cooled water can be used to flush the surface of the downstream metal plate. The water temperature coming out of the heat exchanger 409 is reduced to normal water temperature and is transported to the flushing spray beam 410 to flush the metal plate, thereby flushing away the abrasive residue from 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 separate the residue from the metal plate by flushing, and at the same time recycle the abrasive for reuse.

[0110] Since the water required for flushing accounts for the largest proportion in the descaling device, it is only necessary to cool the water required for flushing, and then after circulating and mixing, the cooling of the circulating water in the entire system can be basically achieved.

[0111] Another part of the water from the water treatment unit is pumped by the fine filter inlet pump 302 to the inclined plate sedimentation tank 303 of the fine filter 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, and the relatively clean water at the top of the inclined plate sedimentation tank 303 is pumped to the fine filter water tank 401. The clean water in the fine filter water tank 401 is pumped to the rinsing spray beam 403 by the fine filter outlet pump 402 to rinse the metal plate treated by the jet generator 101 and washed, and remove the abrasive residue attached to the metal plate.

[0112] In summary, the working liquid of the jet generator 101 mainly includes water and abrasives. The amount of water used is very large and the cost of abrasives is relatively high, both of which need to be recycled. The liquid treated by the working liquid medium after the jet descaling operation includes not only the abrasives and water that need to be recycled, but also the scales on the metal surface and the unusable fragments after the abrasives are broken. This part of the waste needs to be removed to recycle the abrasives and water.

[0113] The recycling of abrasives is firstly carried out by settling in the collecting box 200. The abrasives with large particles, i.e., the abrasives with small damage, are sucked into the venturi mixer after settling and mixed with the circulating return water, and then pumped to the jet generator 101 for recycling. Secondly, there is still a part of abrasives in the top suspension of the collecting box 200 that meet the jet descaling standard. After preliminary settling in the first settling tank 202, they are screened by the cyclone separator 205 and transported to the collecting box 200 for further settling and utilization, thus improving the reuse of abrasives, increasing benefits and reducing costs.

[0114] The recycling of water is very important in the recycling of working fluid. Due to the huge amount of water used, both economic and environmental protection standards must be met. In this application, according to the different requirements for water purity in different working processes, the water cycle is used separately, which greatly reduces the cost and improves the recycling rate of water.

[0115] First, after the suspension is filtered through the second sedimentation tank 203, although the purity of the precipitated water is not high, it can meet the working fluid medium requirement of the jet generator 101. Therefore, this part of the precipitated 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 waste water after the abrasive is removed can be used for flushing the metal plate after being treated by the water treatment unit. The main process here is that the metal plate must be flushed with water to remove the abrasive residue after each jet impact to meet the jet requirements. In addition, the high-temperature water generated by the jet also needs to be cooled. A part of the water treated by the water treatment unit, which accounts for a large amount of the recycled water, is pumped to the heat exchanger 409 by the heat exchanger water pump 414. The refrigerant channel of the heat exchanger 409 is composed of the cooling tower 408, the cooling water tank 407 and the shell side channel of the heat exchanger 409. The water flowing through the heat exchanger 409 is cooled and then transported to the flushing spray beam 410 for flushing the metal plate to clean the abrasive residue on the surface of the metal plate.

[0117] Finally, another part of the water treated by the water treatment unit is purified by 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 water pump 402 to rinse the metal plate, completing the final cleaning of the metal plate, and finally the flushing water and the rinsing water are returned to the collection box 200.

[0118] After the above recycling of abrasives and water, the waste in the inclined plate sedimentation tank 303 is collected and processed by the filter press 304, so that the waste obtained is the least and it is also the most environmentally friendly.

[0119] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0120] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present 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 flushing and rinsing unit; The sedimentation unit is arranged between the descaling unit and the water treatment unit, a cyclone separation unit is arranged between the descaling unit and the sedimentation unit, and the cyclone separation unit is respectively connected to the descaling unit and the water treatment unit through pipelines; A circulation backflow component is provided between the precipitation unit and the descaling unit; The heat exchange unit and the fine filtration unit are respectively connected to the water treatment unit through pipelines, and the flushing and rinsing unit includes a flushing component and a rinsing component; The heat exchange unit is connected to the flushing component through a pipeline, and the fine filtration unit is connected to the rinsing component through a pipeline; The flushing and rinsing unit is connected to the descaling unit through a pipeline, so as to return the flushing and rinsing water to the descaling unit for recycling.

2. The metal descaling wastewater treatment device according to claim 1, characterized in that: The sedimentation unit includes a first sedimentation tank arranged in sequence, and the descaling unit includes a collecting box for receiving descaling wastewater. The collecting box is connected to the first sedimentation tank through a pipeline, and the bottom of the first sedimentation tank is connected to the cyclone separation unit through a lifting pump and a lifting pipeline.

3. The metal descaling wastewater treatment device according to claim 2, characterized in that: The cyclone separation unit comprises a plurality of cyclone separators arranged in parallel, each of the cyclone separators is respectively connected with a water outlet pipe and a slurry outlet pipe, the water outlet pipe is connected with the water treatment unit, and the slurry outlet pipe is connected with the collection box.

4. The metal descaling wastewater treatment device according to claim 2, characterized in that: The sedimentation unit further comprises a second sedimentation tank, which is arranged downstream of the first sedimentation tank, and the top of the first sedimentation tank is connected to the second sedimentation tank through a pipeline; The circulation backflow component comprises a suspension pump and a backflow pipe, the backflow pipe is connected to the bottom of the second sedimentation tank, and the outlet pipe of the suspension pump is connected to the descaling unit.

5. The metal descaling wastewater treatment device according to claim 1, characterized in that: The water treatment unit comprises a treatment pool and a filter assembly installed in the treatment pool, wherein a water inlet baffle and a water outlet baffle are respectively arranged on both sides of the filter assembly to separate the interior of the treatment pool into a water inlet pool and a water outlet pool, and the water outlet pool is respectively connected to the heat exchange unit and the fine filtration unit through pipelines; The filter assembly includes a magnetic filter box, a flat bed filter, a coagulation reaction bed, a sand filter or a membrane filter.

6. The metal descaling wastewater treatment device according to claim 5, characterized in that: 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 water outlet pool through a heat exchange water pump and a heat exchange pipeline, and the shell side is connected to the cooling water tank and the cooling tower respectively through a circulating cooling component.

7. The metal descaling wastewater treatment device according to claim 6, characterized in that: The heat exchanger is connected to a heat exchange water outlet pipe, the flushing assembly includes a flushing spray beam, and the heat exchange water outlet pipe is arranged between the heat exchanger and the flushing spray beam.

8. The metal descaling wastewater treatment device according to claim 5, characterized in that: The fine filtration unit comprises an inclined plate sedimentation tank, and the inclined plate sedimentation tank is connected to the water outlet tank through a fine filtration water inlet pump and a fine filtration water inlet pipeline; The inclined plate sedimentation tank is connected to a filter press and a fine filter water tank through pipelines, the fine filter water tank is connected to a fine filter water pump through pipelines, the rinsing component includes a rinsing spray beam, and the fine filter water pump is connected to the rinsing spray beam through a fine filter water outlet pipeline.

9. The metal descaling wastewater treatment device according to claim 4, characterized in that: The descaling unit comprises a descaling box for allowing the metal plate to pass horizontally, a plurality of 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 collecting box through a pipeline; The collecting box includes a plurality of funnels at the bottom, the funnels correspond to the jet generators one by one, a descaling medium mixer is arranged between the jet generator and the funnel, and the plurality of descaling medium mixers are all connected to the circulating water inlet pipe group and are respectively connected to the water inlet branch pipes of the circulating water inlet pipe group; An abrasive feed pipeline is provided between each of the descaling medium mixers and each of the funnels, the descaling medium mixer comprises a Venturi mixer, the Venturi mixer comprises an abrasive inlet located at the top, and a water inlet and a material outlet respectively located at both sides, the abrasive feed pipeline is connected to the abrasive inlet, the water inlet is connected to a circulating water inlet pump, the circulating water inlet pump is connected to the water inlet branch pipe, and the material outlet is connected to the jet generator through a pipeline; The water outlet end of the water outlet pipe is connected to the circulating water inlet pipe group.

10. A method for treating metal descaling wastewater, carried out by the metal descaling wastewater treatment device according to claim 1, characterized in that: The following steps are involved: The metal plate is descaled by jet flow in the descaling unit, and the descaling wastewater in the descaling unit is passed into the sedimentation unit for sedimentation; The suspended liquid after sedimentation is subjected to cyclone separation and backflow treatment respectively through the cyclone separation unit and the circulation backflow component, the top suspended liquid of the cyclone separation is introduced into the water treatment unit, the abrasive of the cyclone separation is returned to the descaling unit, and the backflow suspended liquid is returned to the descaling unit and mixed with the abrasive in the descaling unit and then circulated and sprayed for descaling; The top suspension after settling is passed into the water treatment unit, and the water treatment unit is used to filter the received top suspension, and the obtained filter residue is discharged; Part of the clear liquid in the water treatment unit is passed into the heat exchange unit, and the other part of the clear liquid is passed into the fine filtration unit; The cooling water after cooling of the heat exchange unit is passed into the flushing component to flush the surface of the metal plate after descaling; The fine filtration water obtained by the fine filtration unit is passed into the rinsing component to rinse the surface of the metal plate after flushing, and the waste obtained by the fine filtration is filtered out by pressure; The flushing water and the rinsing water are circulated back to the descaling unit to be reused in the jet descaling.

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