Sand water separation system and mill scale removal system

Abstract

The present application provides a sand water separation system and an iron oxide scale removal system, the sand water separation system comprising: a separator having an overflow pipe and a sand conveying device, a screening device connected downstream of the sand conveying device; a sand water mixing device outlet connected to a sand water slurry pipe, a clean water outlet pipe of a sewage treatment system in communication with the sand water mixing device, coarse sand screened by the screening device being capable of being conveyed to the sand water mixing device; the separator being used for separating slurry input by a slurry return pipe, and conveying separated sand to the screening device through the sand conveying device, and conveying separated sewage to a cyclone separator through the overflow pipe; the sand water mixing device being capable of mixing coarse sand with clean water conveyed by the clean water outlet pipe, and conveying mixed sand water slurry to a sand water ejector through the sand water slurry pipe, thereby solving the technical problem that the effective action of the circulating sand water slurry gradually decreases in slurry phosphorus removal, and it is difficult to ensure stable long-term circulation of sand water.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot rolling or heat treatment of metal materials, and in particular to a sand-water separation system and an oxide scale removal system. BACKGROUND

[0002] During the hot rolling or heat treatment of metal materials, a dense covering of metal oxides, commonly known as "scale", is formed on the surface of the metal material. The presence of the scale can affect further processing: on the one hand, the surface cracks of the material are not easy to be found, so that the quality of the finished product is affected; on the other hand, the scale is easily pressed into the surface layer of the metal during rolling, and if the subsequent oxide layer falls off, a depression is formed on the surface of the metal plate, causing surface quality problems; at the same time, the presence of the oxide accelerates the wear of the rolling mill or the drawing machine. Therefore, the steel plate must be descaled before entering the cold rolling.

[0003] Currently, the main methods for descaling steel plates are as follows:

[0004] Tool descaling: mainly using steel wire brushes and other tools to polish the surface of the steel, which can remove loose or warped scales, rust, welding slag, etc. Manual tool descaling can achieve Sa2 level; tool descaling is low in efficiency, cannot realize product automation, and is harmful to the human body;

[0005] Acid pickling descaling: strong acid solutions such as sulfuric acid, hydrochloric acid and hydrofluoric acid are commonly used to descale the surface of steel plates. Chemical pickling can remove scales, rust and old coatings. Although chemical cleaning can achieve a certain degree of cleanliness and roughness, acid pickling is prone to over-corrosion and hydrogen embrittlement problems, and acid mist is harmful to the human body and the environment. The production environment of chemical wet pickling process is very poor, and a large amount of residual acid needs to be treated for recycling. The exhaust gas contains a large amount of acidic and corrosive components such as HCl and SO2, which directly pollute the atmosphere;

[0006] Shot blasting descaling: shot blasting is a method of removing metal rust by using metal pellets and using compressed air or mechanical centrifugal force as power and friction. Shot blasting for surface treatment has large impact force and obvious cleaning effect, but shot blasting of steel plates can easily cause workpiece deformation, cause environmental pollution, and can only be operated in a closed space, which is low in working efficiency;

[0007] Slurry descaling: Many domestic and foreign enterprises and research institutions have applied for patent technologies for removing scale from the surface of steel plates using a mixed slurry of particles and water. The main technical solutions are as follows: one is to use high-pressure water jets to carry metal sand particles to impact the surface of the steel plate at high speed to remove the oxide scale; the other is to use a centrifugal shot blasting machine to accelerate the sand-water mixed slurry, and then throw the sand-water mixed slurry onto the surface of the steel plate to remove the oxide scale. The high-pressure water jet method requires a high water supply pressure, and the jet nozzle wears out quickly, with a short service life. The wet shot blasting method requires sand-water separation and water purification and filtration, and the sand-water separation system is complex, with poor sand-water separation effect.

[0008] US patent application US10 / 454357 discloses a cleaning and recycling system for conditioning fluid in a sheet metal trimmer; Chinese invention patent CN103447969B discloses a steel plate descaling, cleaning and air drying device; Chinese utility model patent CN209383520U discloses a working fluid circulating and purifying equipment of a wet shot blasting machine and a wet shot blasting machine; Chinese invention patent CN111376175B discloses a sand liquid circulating system for wet shot blasting. The main shortcomings are as follows: 1. The sand and oxide scale cannot be effectively separated in the sand-water circulating system, which may cause some oxide scale particles to circulate in the sand-water circulating system, and have no effective effect on the removal of the oxide scale on the steel plate; 2. Some sand and oxide scale are discharged from the system at the same time, causing waste of sand and the need to supplement new sand into the system.

[0009] US invention patent US5637029A discloses a method and apparatus for shot blasting a workpiece; Chinese utility model patent CN202922415U discloses a slurry jet wet sand blasting device; Chinese invention patent CN105585163U discloses a water, sand and oxide separation device; Chinese invention patent application CN114031160A discloses a magnetic solid-liquid separation device. The main shortcomings are as follows: 1. The separation effect of sand particles and oxide scale is poor, and the oxide scale particles and fine powder that fall off from the surface of the steel plate cannot be effectively removed, causing the presence of fine oxide iron powder particles in the sand-water circulating system, equipment wear and blockage, and increased power consumption during equipment operation; 2. Broken and worn sand particles cannot be effectively removed after multiple cycles, causing an increase in sand-water circulation, poor oxide scale removal effect, and energy waste.

[0010] Chinese utility model patent CN2936580Y discloses a sand dust separator with a drying device; Chinese utility model patent CN200951525Y discloses a shot separation and dust removal device for a shot blasting machine; Chinese invention patent CN104723225B discloses a magnetic separation device for a shot blasting machine; Chinese utility model patent CN204974175U discloses a magnetic separation device; Chinese invention patent CN110587495B discloses a separation mechanism for impurities of a shot blasting machine. The main shortcomings are as follows: 1, this scheme is only suitable for the separation of dry sand, and the separation effect is poor for the separation of sand-water mixture; 2, the noise is large during the operation of the equipment, and there is a problem of escape of part of the sand particles.

[0011] In summary, in the phosphorus removal of the slurry, the effective action of the circulating sand-water slurry gradually decreases, and it is difficult to ensure the stable and long-term circulation of the sand-water. SUMMARY

[0012] The purpose of the present application is to provide a sand-water separation system and an iron oxide scale removal system to solve the technical problem that the effective action of the circulating sand-water slurry gradually decreases in the phosphorus removal of the slurry, and it is difficult to ensure the stable and long-term circulation of the sand-water.

[0013] The above-mentioned purpose of the present application can be realized by using the following technical scheme:

[0014] The present application provides a sand-water separation system, comprising:

[0015] A separator can be connected to the sewage outlet of the phosphorus removal machine through a slurry return pipe; the separator has an overflow pipe and a sand conveying device;

[0016] A cyclone separator is connected downstream of the overflow pipe, and a sewage treatment system is connected to the sewage outlet of the cyclone separator through a backwater pipeline;

[0017] A screening device is connected downstream of the sand conveying device for screening coarse sand in the sand;

[0018] A sand-water mixing device is connected to the sand-water slurry pipe, the clean water outlet pipe of the sewage treatment system is connected to the sand-water mixing device, and the coarse sand screened by the screening device can be conveyed to the sand-water mixing device;

[0019] The separator is used for separating the slurry input by the slurry return pipe, conveying the separated sand to the screening device through the sand conveying device, and conveying the separated sewage to the cyclone separator through the overflow pipe;

[0020] The sand-water mixing device can mix the coarse sand with the clean water delivered by the clean water outlet pipe, and the mixed sand-water slurry can be delivered to the sand-water thrower through the sand-water slurry pipe.

[0021] In a preferred embodiment, the sand-water separation system comprises a first sedimentation tank and a second sedimentation tank, the overflow pipe, the first sedimentation tank, the second sedimentation tank and the cyclone separator are arranged in sequence, and the sewage separated by the second sedimentation tank can flow to the cyclone separator.

[0022] In a preferred embodiment, a baffle is arranged between the first sedimentation tank and the second sedimentation tank, the baffle is provided with an overflow hole, and the sewage in the first sedimentation tank can flow into the second sedimentation tank through the overflow hole.

[0023] In a preferred embodiment, the overflow hole is circular or polygonal.

[0024] In a preferred embodiment, the length of the overflow hole is not less than 200 mm, or the diameter of the overflow hole is not less than 30 mm.

[0025] In a preferred embodiment, the second sedimentation tank is provided with a ferromagnetic plate.

[0026] In a preferred embodiment, the ferromagnetic plate is arranged on the inclined side wall of the second sedimentation tank, the bottom of the second sedimentation tank is provided with a sand settling baffle, a sand settling area is arranged between the sand settling baffle and the inclined side wall, and the sand can move along the inclined side wall to the sand settling area.

[0027] In a preferred embodiment, the sand-water separation system comprises a sand collecting box, the coarse sand screened by the screening device can be delivered to the sand collecting box, and the sand collecting box is connected with the sand-water mixing device.

[0028] In a preferred embodiment, the particle backflow pipe of the cyclone separator communicates with the sand collecting box to deliver the separated sand to the sand collecting box.

[0029] In a preferred embodiment, the sand collecting box is connected with the abrasive bin through a sand adding amount adjusting valve.

[0030] In a preferred embodiment, the downstream of the sand delivery device is connected with a drying device, the drying device communicates with the sand collecting box through a wet sand adjusting valve, and the drying device communicates with the screening device through a dry sand adjusting valve.

[0031] In a preferred embodiment, a drying device is arranged between the sand delivery device and the screening device.

[0032] In a preferred embodiment, the separator includes a separation chamber and a drum, wherein a magnet device is disposed in the drum, and the drum is at least partially disposed in the separation chamber; the overflow pipe is disposed at the outlet of the separation chamber, and the feed port of the sand conveying device is disposed at the top of the drum.

[0033] In a preferred embodiment, the magnet device is arc-shaped and fixed to the inner wall of the roller.

[0034] In a preferred embodiment, the separation chamber includes an arc-shaped cavity portion, which is coaxial with the roller.

[0035] In a preferred embodiment, the inlet of the separation chamber is provided with a perforated plate.

[0036] In a preferred embodiment, the screening device includes a fine screening zone and a coarse screening zone distributed sequentially from upstream to downstream. A fine sand bin is provided below the fine screening zone, and a coarse sand bin is provided below the coarse screening zone. The coarse sand in the coarse sand bin can be conveyed to the sand-water mixing device.

[0037] In a preferred embodiment, the screening device includes a screw conveyor mechanism and an inner screw guide plate.

[0038] In a preferred embodiment, the screening device includes a sand collection hopper, the outlet of which is connected to the inlet of the screw conveyor mechanism.

[0039] This invention provides an iron oxide scale removal system, comprising: a dephosphorizer, a sand-water ejector, and the aforementioned sand-water separation system. The wastewater outlet of the dephosphorizer is connected to the slurry return pipe, and the sand-water mixing device enables the mixed sand-water slurry to be conveyed to the sand-water ejector through the sand-water slurry pipe.

[0040] The features and advantages of this invention are:

[0041] This sand-water separation system uses a sand-water ejector to project sand-water slurry onto the steel plate surface to remove iron oxide scale. The resulting sand-water mixture is then transported to a separator via a slurry return pipe. The separator efficiently separates sand particles from water. The separated sand particles are conveyed to a screening device, where they are sieved. The coarse sand is then transported to a sand-water mixing device and mixed with purified water treated by a hydrocyclone separator and a wastewater treatment system to form a sand-water slurry. This slurry is then reintroduced into the sand-water ejector for iron oxide scale removal, thus achieving sand particle recycling. This sand-water separation system uses a separator to effectively separate the circulating liquid and abrasive particles, enabling the recycling and purification of both. Furthermore, the screening device effectively removes fine sand particles from the dry sand, ensuring the effective function of the sand-water slurry and minimizing the ineffective energy consumption caused by high fine sand particle content. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the iron oxide scale removal system provided by the present invention;

[0044] Figure 2 This is a schematic diagram of the sand-water separation system provided by the present invention;

[0045] Figure 3 A schematic diagram of the separator in the sand-water separation system provided by the present invention;

[0046] Figure 4 A schematic diagram of the screening device in the sand-water separation system provided by the present invention;

[0047] Figure 5 A schematic diagram of the sand collection box and sand-water mixing device in the sand-water separation system provided by the present invention;

[0048] Figure 6 A schematic diagram of the structure of the primary sedimentation tank and the secondary sedimentation tank in the sand-water separation system provided by the present invention;

[0049] Figure 7 This is a schematic diagram of the descaling machine and sand-water jetting device in the iron oxide scale removal system provided by the present invention.

[0050] Explanation of icon numbers:

[0051] 11. Sand-water slurry pipe; 12. Slurry return pipe; 13. Water return pipe; 14. Particle recovery pipe; 15. Sand collection pipe;

[0052] 2. Separator; 20. Separation chamber; 201. Arc-shaped cavity;

[0053] 21. Overflow pipe; 22. Sand conveying device;

[0054] 23. Perforated plate;

[0055] 24. Drum; 241. Drum shell; 25. Magnet device;

[0056] 26. Slurry distributor; 27. Mortar regulating valve;

[0057] 28. Drying device;

[0058] 281. Wet sand regulating valve;

[0059] 282. Dry sand regulating valve; 283. Sand downcomer;

[0060] 3. Screening device; 31. Screw conveyor mechanism; 32. Inner spiral guide plate;

[0061] 33. Fine screening zone; 331. Fine sand bin; 332. Fine sand regulating valve; 333. Fine sand bucket;

[0062] 34. Coarse screening zone; 341. Coarse sand bin; 342. Coarse sand regulating valve;

[0063] 35. Waste trough; 351. Waste regulating valve; 352. Waste bin;

[0064] 36. Sand collecting hopper; 361. Sand hopper regulating valve;

[0065] 4. Sand collection box; 40. Abrasive particles;

[0066] 41. Granular sedimentation zone; 42. Sand outlet of sedimentation zone; 43. Sand discharge hole of sand collection box; 44. Sand quantity regulating valve;

[0067] 45. Abrasive bin; 451. Sand adding regulating valve;

[0068] 51. Primary sedimentation tank; 511. Primary sand discharge port;

[0069] 512. Drain valve; 513. Wastewater tank;

[0070] 52. Secondary sedimentation tank; 521. Secondary sand discharge port;

[0071] 522. Sewage outlet pipeline; 523. Water flow regulating valve; 524. Second sewage pump; 525. Sewage regulating valve;

[0072] 53. Ferromagnetic plate; 531. Settling baffle; 532. Settling zone;

[0073] 54. Baffle; 541. Overflow hole;

[0074] 6. Hydrocyclone separator;

[0075] 61. Hydrocyclone separator outlet pipeline; 611. Flow regulating valve;

[0076] 62. Sand and water collection chamber; 621. Return sand and water regulating valve;

[0077] 63. Hydrocyclone separator inlet pipe;

[0078] 7. Wastewater treatment system; 71. Wastewater filter;

[0079] 72. Drain valve; 721. Waste discharge bin;

[0080] 73. Clean water tank; 731. Clean water outlet pipe; 732. Clean water regulating valve; 733. Wastewater treatment system inlet;

[0081] 74. Jet pump; 741. Jet water volume regulating valve; 742. Jet water pipeline;

[0082] 8. Sand-water mixing device;

[0083] 81. Export; 811. Export pipe;

[0084] 82. Sand entrance; 83. Water entrance;

[0085] 9. Dephosphorizing machine;

[0086] 91. Pinch roller; 92. Metal plate; 93. Discharge chute; 931. Cleaning and maintenance hole; 932. Discharge regulating valve; 94. Sewage pump;

[0087] 95. Sand and water projectile; 951. Electric motor. Detailed Implementation

[0088] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0089] Option 1

[0090] This invention provides a sand-water separation system, such as Figures 1-7As shown, the sand-water separation system includes: a separator 2, a slurry return pipe 12, a hydrocyclone separator 6, a wastewater treatment system 7, a return water pipe 13, a screening device 3, and a sand-water mixing device 8. The separator 2 is connected to the wastewater outlet of the dephosphorizer 9 via the slurry return pipe 12. The separator 2 has an overflow pipe 21 and a sand conveying device 22. The hydrocyclone separator 6 is connected downstream of the overflow pipe 21, and the wastewater treatment system 7 is connected to the wastewater outlet of the hydrocyclone separator 6 via the return water pipe 13. The screening device 3 is connected downstream of the sand conveying device 22 and is used to screen out coarse sand from the sand. The outlet of the sand-water mixing device 8 is... 81 connects to the sand-water slurry pipe 11. The clean water outlet pipe 731 of the sewage treatment system 7 is connected to the sand-water mixing device 8. The coarse sand screened by the screening device 3 can be conveyed to the sand-water mixing device 8. The separator 2 is used to separate the slurry input by the slurry return pipe 12 and convey the separated sand to the screening device 3 through the sand conveying device 22. The separated sewage is conveyed to the cyclone separator 6 through the overflow pipe 21. The sand-water mixing device 8 can mix the coarse sand with the clean water conveyed by the clean water outlet pipe 731 and convey the mixed sand-water slurry to the sand-water ejector 95 through the sand-water slurry pipe 11.

[0091] In this sand-water separation system, the sand-water ejector 95 ejects the sand-water slurry onto the steel plate surface to remove iron oxide scale. The ejected sand-water slurry is then transported to the separator 2 via the slurry return pipe 12. The separator 2 achieves efficient separation of sand particles and water. The separated sand particles are conveyed to the screening device 3 via the sand conveying device 22. The screening device 3 performs screening, and the screened coarse sand is conveyed to the sand-water mixing device 8 and mixed with the purified water treated by the hydrocyclone separator 6 and the sewage treatment system 7 to form a sand-water slurry. This slurry then re-enters the sand-water ejector 95 to remove iron oxide scale, thus achieving the recycling of sand particles. This sand-water separation system uses the separator 2 to effectively separate the circulating liquid and abrasive particles, enabling the recycling and purification of both. Furthermore, the screening device 3 screens the dry sand, effectively removing fine sand particles, ensuring the effective function of the sand-water slurry, and helping to maintain the coarse sand content while reducing the ineffective energy consumption caused by the high fine sand particle content.

[0092] In one embodiment, the wastewater treatment system 7 includes a wastewater filter 71 and a clean water tank 73. The purified circulating liquid is pumped to a hydrocyclone separator 6 by a second wastewater pump 524 for fine sand removal. The circulating liquid after passing through the hydrocyclone separator 6 enters the wastewater treatment system 7 and is filtered by the wastewater filter 71. The filtered circulating liquid is collected in the clean water tank 73 and pumped to a sand-water mixing device 8 by a jet pump 74 to achieve effective recycling of the circulating liquid.

[0093] Specifically, a sewage filter 71 is installed in the sewage treatment system 7. A drain valve 72 and a clean water outlet pipe 731 are installed at the bottom of the sewage treatment system 7. One end of the clean water outlet pipe 731 is connected to a clean water regulating valve 732. One end of the clean water regulating valve 732 is connected to a jet pump 74. The jet pump 74 is connected to one inlet end of a sand-water mixing device 8 through a jet water pipe 742. The other inlet end of the sand-water mixing device 8 is connected to the outlet of a sand quantity regulating valve 44. The outlet of the sand-water mixing device 8 is connected to a sand-water slurry pipe 11. The outlet of the sand-water slurry pipe 11 is connected to the inlet end of a sand-water ejector 95. A motor 951 drives the sand-water ejector 95 to rotate at high speed, which propels the sand-water slurry onto the surface of the steel plate at high speed. The high-speed impact of the sand-water slurry removes the iron oxide scale from the steel plate. The sand-water mixture that is propped onto the surface of the steel plate collects at the bottom of the descaling tank. During the water circulation, a small amount of fine abrasive particles and detached iron oxide scale particles flow into the sewage treatment system 7 along with the water circulation system. After being filtered by the sewage filter 71, the fine abrasive particles and iron oxide scale are removed by the filter. The extremely fine particles settle at the bottom of the clean water tank 73 and are discharged through the drain valve 72 at the bottom of the clean water tank 73. The discharged fine particles are discharged into the waste discharge bin 721 and collected for recycling as iron-containing sludge raw material.

[0094] In one embodiment, the sand-water separation system includes a primary sedimentation tank 51 and a secondary sedimentation tank 52. An overflow pipe 21, the primary sedimentation tank 51, the secondary sedimentation tank 52, and a hydrocyclone separator 6 are arranged sequentially. Wastewater separated from the secondary sedimentation tank 52 can flow to the hydrocyclone separator 6. Specifically, the primary sedimentation tank 51 is equipped with a primary sand discharge hole 511 for discharging the deposited sand. An empty valve 512 is installed at the bottom of the primary sedimentation tank 51 for draining the sand-water mixture during maintenance. A wastewater tank 513 is located below the first empty valve 512.

[0095] like Figure 6 As shown, a baffle 54 is provided between the primary sedimentation tank 51 and the secondary sedimentation tank 52. An overflow hole 541 is provided on the baffle 54, and the sewage in the primary sedimentation tank 51 can flow into the secondary sedimentation tank 52 through the overflow hole 541.

[0096] Furthermore, the overflow orifice 541 is circular or polygonal. Specifically, the shape of the overflow orifice 541 can be circular, polygonal, arc polygonal, combined polygonal, prism, etc.

[0097] Furthermore, the length of the overflow hole 541 is not less than 200 mm, or the diameter of the overflow hole 541 is not less than 30 mm. When the overflow hole 541 is non-circular, its maximum cross-sectional length is used as the reference, and this length is not less than 200 mm; when the overflow hole 541 is circular, its diameter is used as the reference, and it is not less than 200 mm.

[0098] Specifically, the baffle 54 has at least three layers of overflow holes 541 in its height. The overflow holes 541 can be arranged at equal intervals or non-equal intervals in the height direction; the overflow holes 541 can also be arranged at equal intervals or non-equal intervals in the width direction. The diameter of the overflow holes 541 on the baffle 54 can be arranged with equal diameters or with multiple diameters arranged in different areas.

[0099] In one embodiment, the secondary sedimentation tank 52 is equipped with a ferromagnetic plate 53, which adsorbs fine abrasive particles to achieve secondary purification of the circulating liquid. Preferably, the ferromagnetic plate 53 can be in the form of an electromagnet to achieve dynamic adjustment of the magnetic field strength, thus meeting the dynamic adjustment of the amount of sand adsorbed.

[0100] Specifically, the clear water that has settled in the primary sedimentation tank 51 can flow into the secondary sedimentation tank 52 through the overflow hole 541. A ferromagnetic plate 53 is installed on the side wall of the secondary sedimentation tank 52 near the baffle 54. The ferromagnetic plate 53 can effectively adsorb fine iron particles and steel sand in the secondary sedimentation tank 52, further purifying the circulating liquid. The secondary sedimentation tank 52 is equipped with a sand settling baffle 54 and a sand settling zone. The iron particles and steel sand adsorbed by the ferromagnetic plate 53 are deposited in the sand settling zone and can be discharged through the secondary sand discharge hole 521. A sewage outlet pipe and a water flow regulating valve 523 are installed at the bottom of the secondary sedimentation tank 52. The outlet of the water flow regulating valve 523 is connected to the second sewage pump 524. A sewage regulating valve 525 is installed at the outlet of the second sewage pump 524. The outlet of the sewage regulating valve 525 is connected to the inlet pipe 63 of the hydrocyclone separator. A flow regulating valve 611 is installed at the outlet of the hydrocyclone separator 6. The outlet pipe 61 of the hydrocyclone separator is connected to the return water pipe 13. The outlet of the return water pipe 13 is connected to the sewage treatment system inlet 733.

[0101] Furthermore, the ferromagnetic plate 53 is disposed on the inclined sidewall of the secondary sedimentation tank 52; a sand settling baffle 531 is disposed at the bottom of the secondary sedimentation tank 52, and a sand settling zone 532 is disposed between the sand settling baffle 531 and the inclined sidewall. The sand can move along the inclined sidewall to the sand settling zone 532 to collect iron-containing particles and steel sand particles adsorbed by the ferromagnetic plate 53. After a certain amount of sand has settled in the sand settling zone 532, the sand can be discharged by opening the secondary sand discharge hole 521. Preferably, the ferromagnetic plate 53 is laid on the outer wall of the secondary sedimentation tank 52, and the sand settling baffle 531 and the sand settling zone 532 are located at the bottom of the sidewall of the secondary sedimentation tank 52.

[0102] In one embodiment, the sand-water separation system includes a sand collection box 4, and the coarse sand screened by the screening device 3 can be transported to the sand collection box 4. The sand collection box 4 is connected to the sand-water mixing device 8.

[0103] like Figure 5As shown, a sand outlet 42 is provided at the bottom of the particle sedimentation zone 41 inside the sand collection box 4. A sand quantity regulating valve 44 is installed at the sand outlet 42, which is connected to the sand inlet 82 of the sand-water mixing device 8. A jet water pipe 742 is connected to the water inlet 83 of the sand-water mixing device 8. The sand-water mixing device 8 is connected to the sand-water slurry pipe 11 via an outlet pipe 811. The sand-water mixing device 8 is a three-way mechanism, with one inlet for introducing jet water, another for introducing sand particles, and one outlet for discharging the sand-water mixture. A sand collection box discharge hole 43 is also provided on the side wall of the particle sedimentation zone 41.

[0104] like Figure 2 As shown, a jet water flow regulating valve 741 is installed between the clean water outlet pipe 731 of the sewage treatment system 7 and the sand-water mixing device 8. The sand flow regulating valve 44 can dynamically adjust the sand flow rate of sand particles entering the sand-water mixing device 8 from the sand collection box 4, realizing dynamic adjustment of different sand quantities; the sand flow regulating valve 44 and the jet water flow regulating valve 741 can realize dynamic adjustment of the sand-water ratio.

[0105] Preferably, the ratio of water to solid particles by weight is 1:0.1 to 4, which is achieved by adjusting the sand volume regulating valve 44 and the water jet volume regulating valve 741.

[0106] Preferably, the sand-to-water ratio can be dynamically adjusted by means of the sand volume regulating valve 44 and the water volume regulating valve 523, with the water to solid particles calculated by volume ratio as 1:0.2 to 0.6.

[0107] Preferably, by adjusting the sand volume regulating valve 44 and the water volume regulating valve 523, the sand and water injection rate of a single sand-water mixing device 8 is 200 kg / min to 900 kg / min.

[0108] Preferably, by closing the sand volume regulating valve 44 and opening the water volume regulating valve 523, a single sand-water mixing device 8 can clean the steel plate surface by spraying high-pressure water individually.

[0109] Furthermore, the sand collection box 4 is connected to the abrasive chamber 45 via a sand-adding regulating valve 451, and the abrasive chamber 45 is used to replenish sand to the sand collection box 4. Figure 2 As shown, a sand-adding regulating valve 451 is provided between the abrasive bin 45 and the sand collection box 4 to regulate the amount of sand added to the abrasive bin 45.

[0110] In one embodiment, the particle return pipe of the hydrocyclone separator 6 is connected to the sand collection box 4 to transport the separated sand to the sand collection box 4. The fine sand deposited in the hydrocyclone separator 6 is deposited in the sand-water collection chamber 62. When the deposition amount reaches a predetermined amount, the return sand-water regulating valve 621 is opened to return the particles to the sand collection box 4, realizing the recycling of sand particles. The fine sand can be transported to the sand-water ejector 95 through the sand-water slurry pipe 11. The fine sand is transported to the magnetic separator 2 through the sewage pump 94. Some of the fine sand passes through the drying device 28 and then through the screening device 3 to enter the fine sand chamber 331, thereby removing the failed fine abrasive particles from the circulation system.

[0111] Furthermore, a sand-water collection chamber 62 is provided at the bottom of the hydrocyclone 6. The outlet of the sand-water collection chamber 62 is connected to the return sand-water regulating valve 621. The outlet of the return sand-water regulating valve 621 is connected to the sand collection box 4 through the particle recovery pipe 14, so as to realize the recycling of sand particles in the hydrocyclone 6.

[0112] Preferably, a wastewater regulating valve 525 is provided at the wastewater inlet of the cyclone separator 6, and / or a flow regulating valve 611 is provided at the wastewater outlet of the cyclone separator 6.

[0113] In one embodiment, the separator 2 includes a separation chamber 20 and a drum 24. A magnet device 25 is disposed in the drum 24, and the drum 24 is at least partially disposed in the separation chamber 20. An overflow pipe 21 is disposed at the outlet of the separation chamber 20, and the feed port of the sand conveying device 22 is disposed at the top of the drum 24. The separator 2 is a magnetic separator 2. A magnetic separator 2 is disposed in the sand-water separation system to achieve the initial separation of abrasive particles and circulating liquid. The separated solid particles can have a diameter of 0.30 mm to 0.8 mm, such as steel grit, steel shot, steel shavings, glass microspheres, garnet, sand grains, and brown corundum. Further, the solid particles with a diameter of 0.30 mm to 0.8 mm are ferromagnetic materials that can be adsorbed by the ferromagnetic plate 53, preferably steel grit, steel shot, steel shavings, etc.

[0114] Furthermore, such as Figure 3 As shown, the magnet device 25 is arc-shaped and fixed to the inner wall of the roller 24. The magnet device 25 can rotate together with the roller 24. Specifically, the roller 24 includes a roller housing 241, and the magnet device 25 is attached to the inner wall of the roller housing 241. Furthermore, the separation chamber 20 includes an arc-shaped cavity 201, which is coaxial with the roller 24.

[0115] In one embodiment, an orifice plate 23 is provided at the inlet of the separation chamber 20. The circulating liquid filtered by the orifice plate 23 of the magnetic separator 2 enters the primary sedimentation tank 51 and the secondary sedimentation tank 52 through the overflow pipe 21 for secondary separation of abrasive particles. The orifice plate 23 of the magnetic separator 2 effectively separates sand particles and circulating liquid. The main component of the circulating liquid is water, and the circulating liquid flows into the primary sedimentation tank 51 through the overflow pipe 21. The bottom of the primary sedimentation tank 51 is provided with a primary sand discharge hole 511 and a drain valve 512. A baffle 54 is provided between the primary sedimentation tank 51 and the secondary sedimentation tank 52. A certain number of overflow holes 541 are provided on the baffle 54. The orifice plate 23 and the baffle 54 work together to perform separation in stages.

[0116] In one embodiment, a drying device 28 is provided between the sand conveying device 22 and the screening device 3. The separated ferromagnetic abrasive particles are dried by passing through the drying device 28 after passing through the sand conveying device. The dried sand is then screened by the screening device 3 to remove fine sand particles. The coarse sand particles enter the sand collection box 4 and then enter the sand-water mixing device 8 into the sand-water slurry pipe 11.

[0117] Furthermore, the downstream of the sand conveying device 22 is connected to the drying device 28. The drying device 28 is connected to the sand collection box 4 through the wet sand regulating valve 281 and to the screening device 3 through the dry sand regulating valve 282. Without turning on the drying device 28, the wet sand regulating valve 281 can be opened and the dry sand regulating valve 282 closed, allowing wet sand containing a certain amount of moisture to enter the sand collection box 4 and regulating the moisture content of the abrasive particles 40 in the sand collection box 4. The sand conveying device 22 can be a wet sand screw conveyor. When the sand particles conveyed by the wet sand screw conveyor pass through the drying device 28, the drying device 28 can be closed. The wet sand containing a certain amount of moisture flows into the sand collecting pipe 15 through the regulating valve and finally collects into the sand collection box 4, achieving continuous conveying of wet sand while simultaneously regulating the moisture content of the sand particles in the sand collection box 4.

[0118] In one embodiment, the screening device 3 includes a fine screening zone 33 and a coarse screening zone 34 distributed sequentially from upstream to downstream. A fine sand bin 331 is provided below the fine screening zone 33, and a coarse sand bin 341 is provided below the coarse screening zone 34. The coarse sand in the coarse sand bin 341 can be transported to the sand-water mixing device 8 through the sand collection box 4.

[0119] like Figure 4As shown, the screening device 3 includes a screw conveyor mechanism 31 and an inner screw guide plate 32. The inner screw guide plate 32 is installed on the inner wall of the coarse screening zone 34 and the fine screening zone 33 of the screening device 3 to guide the sand particles during the screening process, promoting the smooth passage of sand particles through the fine screening zone 33 and the coarse screening zone 34. The width of the inner screw guide plate is not less than 20 mm, and the preferred spacing between the guide plates is 200–600 mm. In one embodiment, the screening device 3 may further include a sand collection hopper 36, the outlet of which is connected to the inlet of the screw conveyor mechanism 31.

[0120] The sand-water separation system provided by this invention can be used in conjunction with a phosphorus removal machine 9, such as... Figure 1 As shown, the descaling machine 9 uses a motor 951 to drive a sand-water ejector 95 to propel the sand-water slurry at high speed onto the surface of the steel plate, using the impact of the high-speed particles to remove iron oxide scale. The sand-water mixture after propagation is pumped by a wastewater pump 94 through a slurry return pipe 12 to a magnetic separator 2. The magnetic separator 2 uses a rotating drum 24 structure and a built-in partial magnet device 25 to achieve efficient separation of sand particles and water. The separated sand particles are conveyed by a sand conveying device 22 through a drying device 28, and can optionally enter a sand collecting pipe 15 and flow into a sand collecting box 4; or they can flow into a sand collecting hopper 36 through a sand downcomer 283. The sand flowing into the sand collecting hopper 36 enters a screening device 3 under the condition of flow rate control by a regulating valve. The screening device 3 is a screw conveyor. The system consists of mechanism 31, fine screening zone 33, and coarse screening zone 34. After being dried by drying device 28, sand particles enter sand collection hopper 36 through dry sand regulating valve 282. The sand particles fall into screw conveyor mechanism 31 and are conveyed into fine screening zone 33 for screening. Fine sand falls into fine sand bin 331. Coarse sand is screened in coarse screening zone 34 and falls into coarse sand bin 341. Other large particles of waste fall into waste bin 352 through waste trough 35. Coarse sand in coarse sand bin 341 enters sand collection box 4 through sand quantity regulating valve 44. The sedimented particles in sand collection box 4 are mixed with sand and water by sand-water mixing device 8 to form sand-water slurry, which then enters sand-water ejector 95 for iron oxide scale removal, thus achieving sand particle recycling. Figure 4 As shown, the waste trough 35 is equipped with a waste regulating valve 351.

[0121] Specifically, the operation steps of this sand-water separation system include:

[0122] 1) Load a pre-set amount of abrasive particles into the abrasive bin 45, open the abrasive bin 45 sand quantity regulating valve 44, load a pre-set amount of abrasive particles into the particle sedimentation zone 41 in the sand collection box 4, and close the abrasive bin 45 sand quantity regulating valve 44.

[0123] 2) Open the descaling machine discharge regulating valve 932, open the jet water pipeline 742 jet water volume regulating valve 741, open the mortar regulating valve 27 on the slurry return pipe 12, turn on the motor of the magnetic separator 2, turn on the sand conveying device, turn off the drying device 28, turn off the dry sand regulating valve 282, turn on the wet sand regulating valve 281, open the sewage outlet pipeline 522 water volume regulating valve 523, and open the sewage regulating valve 525 and flow regulating valve 611 of the cyclone separator 6;

[0124] 3) Turn on the sewage filter 71, turn on the motor 951 of the sand and water ejector 95, turn on the jet water pump 74, observe whether the water flow of the sand and water ejector 95 is normal, observe whether the sand and water liquid level in the discharge chute 93 reaches the predetermined height, and turn on the sewage pump 94.

[0125] 4) After the water flow stabilizes and the sand is thrown, open the sand quantity regulating valve 44. When the sand-water mixture is thrown by the sand-water ejector 95 under normal flow conditions, the steel plate in the descaling box is conveyed forward.

[0126] 5) In actual production, the sand volume regulating valve 44 and the spray water volume regulating valve 741 can be dynamically adjusted according to the detected descaling effect on the steel plate surface to adjust the sand-water ratio. At the same time, the flow rate of the sand-water mixture can be adjusted to achieve different sand-water spraying volumes required for different steel plate surface qualities.

[0127] 6) When the sand-water slurry enters the magnetic separator 2 from the slurry distributor 26, the separated circulating liquid flows through the primary sedimentation tank 51 and the secondary sedimentation tank 52. When the height of the circulating liquid in the secondary sedimentation tank 52 reaches the predetermined position, the second sewage pump 524 is turned on.

[0128] 7) During the shutdown process of the steel plate iron oxide scale equipment, after the steel plate descaling is completed, close the sand quantity regulating valve 44, then close the jet water pump 74, close the motor 951 of the sand-water ejector 95, close the discharge regulating valve 932 of the descaling machine 9, close the jet water quantity regulating valve 741 on the jet water pipeline 742 of the sand-water mixing device 8, close the sewage pump 94, close the sewage filter 71; close the magnetic separator 2, close the water quantity regulating valve 523 of the sewage outlet pipeline 522, and close the sewage regulating valve 525 and the flow regulating valve 611 of the cyclone separator 6.

[0129] 8) After the descaling system has been running for a certain period of time, observe the removal effect of iron oxide scale on the steel plate. If the descaling effect is significantly reduced and the fine sand content in the sand particle size distribution exceeds the predetermined ratio, turn on the drying device 28, turn on the dry sand regulating valve 282 set on the sand downcomer 283, turn on the screw conveyor 31, and then turn on the sand hopper regulating valve 361 to screen the dry sand. The fine sand enters the fine sand bin 331 after screening, the coarse sand enters the coarse sand bin 341 after passing through the coarse screening area 34, and other waste enters the waste bin 352 after passing through the waste trough 35. The coarse sand enters the sand collection box 4 through the coarse sand regulating valve 342, and the fine sand enters the fine sand bin 333 through the fine sand regulating valve 332. The fine sand can be used as fine sand for subsequent fine descaling or can be treated as waste.

[0130] The sand-water separation system provided by this invention has the following characteristics and beneficial effects:

[0131] (1) The magnetic separator 2 is used to achieve effective separation of circulating liquid and abrasive particles, and realize the recycling and purification of circulating liquid and abrasive particles;

[0132] (2) The wet sand is dried by the drying device 28 and the dry sand is screened by the screening device 3 to effectively remove fine sand particles, achieve the effective effect of sand-water slurry, and reduce the ineffective energy consumption caused by the content of fine sand particles.

[0133] (3) By using a series connection of primary sedimentation tank 51 and secondary sedimentation tank 52, an overflow hole 541 structure and a ferromagnetic plate 53, the fine sand and iron oxide powder particles in the circulating liquid are effectively removed, reducing the wear and blockage of the water circulation system by the fine sand.

[0134] (4) The fine sand deposited in the cyclone separator 6 is deposited in the sand and water collection bin 62. When the amount of sedimentation reaches the predetermined amount, the return sand and water regulating valve 621 is opened to return the particles to the sand collection box 4, so as to realize the recycling of sand particles. The fine sand can be transported to the sand and water ejector 95 through the sand and water slurry pipe 11. The fine sand is transported to the magnetic separator 2 through the sewage pump 94. Some of the fine sand passes through the drying device 28 and then enters the fine sand bin 331 through the screening device 3, thereby removing the failed fine abrasive particles from the circulation system.

[0135] (5) By adopting different overflow hole 541 shapes, the turbulence of water flowing through the overflow hole 541 can be effectively controlled, thereby improving the efficiency of sand-water separation and the amount of sediment in the primary sedimentation tank 51, and reducing the loss of sediment particles into the secondary sedimentation tank area.

[0136] Option 2

[0137] This invention provides an iron oxide scale removal system, such as... Figure 1As shown, it includes: a dephosphorizer 9, a sand-water ejector 95 and the aforementioned sand-water separation system. The wastewater outlet of the dephosphorizer 9 is connected to the slurry return pipe 12. The sand-water mixing device 8 can transport the mixed sand-water slurry to the sand-water ejector 95 through the sand-water slurry pipe 11.

[0138] During operation, this iron oxide scale removal system utilizes a sand-water ejector 95 for descaling. Abrasive and water are mixed to obtain a slurry, which is then propelled onto the surface of the hot-rolled steel plate through the sand-water ejector 95 to remove the iron oxide scale. A sand-water separation system is used to achieve efficient separation of sand and water, enabling efficient recycling of the sand-water system. This iron oxide scale removal system possesses the technical features and beneficial effects of the aforementioned sand-water separation system, which will not be elaborated further here. Figure 7 As shown, the dephosphorizing machine 9 is equipped with a pinch roller 91, a metal plate 92, and a cleaning and maintenance hole 931.

[0139] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A sand-water separation system, characterized in that, include: The separator and the slurry return pipe are provided, wherein the separator is connected to the wastewater outlet of the phosphorus removal machine via the slurry return pipe; the separator has an overflow pipe and a sand conveying device. The system includes a hydrocyclone separator, a wastewater treatment system, and a return water pipeline. The hydrocyclone separator is connected downstream of the overflow pipe, and the wastewater treatment system is connected to the wastewater outlet of the hydrocyclone separator through the return water pipeline. A screening device, connected downstream of the sand conveying device, is used to screen out coarse sand from the sand. A sand-water mixing device, the outlet of which is connected to a sand-water slurry pipe, the clean water outlet pipe of the sewage treatment system is connected to the sand-water mixing device, and the coarse sand screened out by the screening device can be transported to the sand-water mixing device. The separator is used to separate the slurry input from the slurry return pipe, and to transport the separated sand to the screening device through the sand conveying device, and to transport the separated wastewater to the hydrocyclone separator through the overflow pipe; The sand-water mixing device can mix coarse sand with the clean water delivered by the clean water outlet pipe, and deliver the mixed sand-water slurry to the sand-water ejector through the sand-water slurry pipe. The sand-water separation system includes a primary sedimentation tank and a secondary sedimentation tank. The overflow pipe, the primary sedimentation tank, the secondary sedimentation tank, and the hydrocyclone are arranged in sequence. The wastewater separated by the secondary sedimentation tank can flow to the hydrocyclone separator. A baffle is provided between the primary sedimentation tank and the secondary sedimentation tank, and an overflow hole is provided on the baffle, so that the sewage in the primary sedimentation tank can flow into the secondary sedimentation tank through the overflow hole; The secondary sedimentation tank is equipped with ferromagnetic plates; The ferromagnetic plate is disposed on the inclined side wall of the secondary sedimentation tank; The bottom of the secondary sedimentation tank is provided with a sand settling baffle, and a sand settling zone is provided between the sand settling baffle and the inclined sidewall, so that the sand can move along the inclined sidewall to the sand settling zone.

2. The sand-water separation system according to claim 1, characterized in that, The overflow hole is circular or polygonal.

3. The sand-water separation system according to claim 1, characterized in that, The length of the overflow hole is not less than 200 mm, or the diameter of the overflow hole is not less than 30 mm.

4. The sand-water separation system according to claim 1, characterized in that, The sand-water separation system includes a sand collection box, and the coarse sand screened by the screening device can be transported to the sand collection box. The sand collection box is connected to the sand-water mixing device.

5. The sand-water separation system according to claim 4, characterized in that, The particle return pipe of the cyclone separator is connected to the sand collection box to transport the separated sand to the sand collection box.

6. The sand-water separation system according to claim 4, characterized in that, The sand collection box is connected to the abrasive bin via a sand-adding regulating valve; A drying device is connected downstream of the sand conveying device. The drying device is connected to the sand collection box through a wet sand regulating valve and to the screening device through a dry sand regulating valve.

7. The sand-water separation system according to claim 1, characterized in that, A drying device is provided between the sand conveying device and the screening device; The separator includes a separation chamber and a drum, wherein a magnet device is disposed in the drum, and the drum is at least partially disposed in the separation chamber; The overflow pipe is located at the outlet of the separation chamber, and the feed port of the sand conveying device is located at the top of the roller.

8. The sand-water separation system according to claim 7, characterized in that, The magnet device is arc-shaped and is fixed to the inner wall of the roller.

9. The sand-water separation system according to claim 7, characterized in that, The separation chamber includes an arc-shaped cavity portion, which is coaxial with the roller.

10. The sand-water separation system according to claim 7, characterized in that, The inlet of the separation chamber is provided with a perforated plate.

11. The sand-water separation system according to claim 1, characterized in that, The screening device includes a fine screening zone and a coarse screening zone distributed sequentially from upstream to downstream. A fine sand bin is provided below the fine screening zone, and a coarse sand bin is provided below the coarse screening zone. The coarse sand in the coarse sand bin can be transported to the sand-water mixing device.

12. The sand-water separation system according to claim 11, characterized in that, The screening device includes a screw conveyor mechanism and an inner screw guide plate.

13. The sand-water separation system according to claim 12, characterized in that, The screening device includes a sand collecting hopper, the outlet of which is connected to the inlet of the screw conveyor mechanism.

14. A system for removing iron oxide scale, characterized in that, include: The dephosphorizing machine, the sand-water ejector, and the sand-water separation system according to any one of claims 1-13, wherein the wastewater outlet of the dephosphorizing machine is connected to the slurry return pipe, and the sand-water mixing device enables the mixed sand-water slurry to be conveyed to the sand-water ejector through the sand-water slurry pipe.

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