Sea sand purification system

Abstract

The application discloses a kind of sea sand purification systems, belong to sea sand purification field, including flow breaker and sand-water separation device;Flow breaker includes inlet, outlet and flow channel, inlet is used to join by sea sand and water fully mixed and formed sand-water mixture, flow channel is used to make sand-water mixture in flow channel from inlet to outlet with certain flow speed and flow, outlet is used to discharge sand-water mixture;Sand-water separation device is used to sand-water separation to the sand-water mixture discharged from the outlet of flow breaker, remove harmful substances from sea sand and enter water with water discharge together.The application can fully remove harmful substances on the surface of sea sand and in fine gap, pore, improve the chemical combination activity of sand body and cementing material, the chloride ion content of purified sea sand can be reduced to 0.000%~0.002%, reach the state of reducing sea sand into river sand before entering sea, the use of purified sea sand will not cause concrete steel bar corrosion and concrete deterioration, good durability, low cost.

Description

Technical Field

[0001] The present invention relates to the field of sea sand purification, in particular to a sea sand purification system. Background Art

[0002] In engineering construction, concrete is the most widely used and widely used material. In concrete, sand and gravel are densely packed and held together by the physical and chemical bonding of cementitious materials. The better the chemical bonding, the less susceptible it is to changes in the external environment, and the greater its strength and durability. Therefore, the strength, surface activity, cleanliness, gradation, particle shape, and harmful substances (such as chloride ion content, organic matter content, mud content, and mud block content) of construction sand significantly affect the workability, strength, and durability of concrete. Sea sand is terrestrial sand, sharing the same origin as river sand. This is because after natural weathering of rock, it is deposited in different locations by external forces such as mountain torrents and river transport. When deposited on land, it is called river sand, while when deposited in the sea, it is called sea sand. The physical and chemical properties of these two natural sands are similar.

[0003] Sea sand cannot be used directly in construction projects because it contains chloride ions and other harmful substances. If sea sand is used directly in construction projects, it will cause steel corrosion and deterioration of concrete, so sea sand needs to be purified.

[0004] Traditional sea sand purification mainly focuses on the corrosion of steel bars by chloride ions. Based on the characteristics of chloride salts being highly soluble in water and being able to dissolve quickly in water, the mainstream sea sand purification method is water washing. Through water washing, chloride ions are dissolved in water, and then through sand and water separation, the chloride ions dissolved in water are discharged and removed with wastewater.

[0005] However, the traditional sea sand washing method cannot effectively remove the chloride ions in the sea sand. Moreover, the sea sand cleaned by the traditional washing method will continuously precipitate chloride ions, which cannot make the chloride ion content in the sea sand reach the level of river sand, nor can it remove other harmful substances on the surface of the sea sand that cause the deterioration of concrete.

[0006] In 2007, the inventors investigated numerous "sea sand house" projects and discovered that nearly all of them, in addition to steel corrosion, also experienced a decrease in concrete strength and deterioration. This phenomenon also occurred with unreinforced concrete made from sea sand. Some projects, even with chloride ion levels below the maximum chloride ion limit for concrete in corrosive environments, still experienced steel corrosion and concrete degradation.

[0007] Combining this practical research with various indicators of marine substances and sea sand during and after cleaning, we found that, in addition to chloride ions, which cause steel corrosion, sea sand also contains other harmful substances on its surface that can degrade concrete. Traditional sea sand washing methods continuously release chloride ions during cleaning, failing to effectively remove them. Furthermore, they also fail to remove other harmful substances on the sand's surface that contribute to concrete degradation, ultimately failing to restore the sand to its original state before entering the sea. Summary of the Invention

[0008] The present invention provides a sea sand purification system, which can fully remove harmful substances on the surface of sea sand and in fine cracks and pores, so as to restore the sea sand to the state of river sand before entering the sea. The purified sea sand will not cause rust of concrete reinforcement and deterioration of concrete after use, and has good durability and low cost.

[0009] The present invention provides the following technical solutions:

[0010] A sea sand purification system includes a flow flusher and a sand-water separation device;

[0011] The flushing device includes an inlet and an outlet, wherein the inlet and the outlet are connected by a flushing channel, the inlet is used to add a sand-water mixture formed by fully mixing sea sand and water, the flushing channel is used to allow the sand-water mixture to flow from the inlet to the outlet at a certain flushing speed in the flushing channel, and the outlet is used to discharge the sand-water mixture;

[0012] The sand-water separation device is arranged at the outlet of the flusher, and is used to separate the sand-water mixture discharged from the outlet of the flusher, and discharge the harmful substances removed from the sea sand and entering the water together with the water;

[0013] Among them, the amount of water in the sand-water mixture should at least fill the gaps when the sea sand is naturally accumulated to ensure that the sea sand is immersed in water; the selection of the flushing speed should ensure that the sand-water mixture maintains sufficient mixing of sea sand and water during the flushing process to avoid sea sand sedimentation.

[0014] Furthermore, the weight ratio of sea sand to water in the sand-water mixture is not greater than 2.5:1.

[0015] Furthermore, the flow velocity of the sand-water mixture is not less than 1.5 m / s.

[0016] Furthermore, the shape of the flushing channel is a groove with an opening on the upper side. The flushing channel is arranged at an angle. The top end of the flushing channel is the inlet of the flushing device, and the bottom end is the outlet of the flushing device. The sand and water mixture flows from the inlet to the outlet under the action of gravity, water impact force and / or mechanical power.

[0017] Furthermore, the inclination angle range of the flushing channel is [2°, 90°).

[0018] Furthermore, a splash-proof top cover is provided on the upper opening of the flushing channel.

[0019] Furthermore, the shape of the flushing channel is a tube with closed sides, and the flushing channel is arranged horizontally, inclined or vertically. One end of the flushing channel is the inlet of the flusher, and the other end is the outlet of the flusher. The sand and water mixture flows from the inlet to the outlet under the action of gravity, positive pressure pushing force, negative pressure suction force and / or mechanical power.

[0020] Furthermore, the flusher is a single-stage flusher or a multi-stage flusher used in combination. When the flusher is a multi-stage flusher used in combination, the sand-water separation device is provided at the outlet of several stages of flushers including the last stage.

[0021] Furthermore, a dehydration device is provided after the sand-water separation device, and the dehydration device is used to dehydrate the sea sand after the sand-water separation.

[0022] Furthermore, the sea sand purification system also includes a waste screening machine, which is arranged before the inlet of the flushing device and is used to screen out coarse particles of waste in the sea sand.

[0023] Furthermore, the sea sand purification system further includes a conveying device;

[0024] The conveying device is used to add the sand-water mixture into the inlet of the flushing device, or the conveying device is used to add sea sand and water into the inlet of the flushing device.

[0025] Furthermore, a disturbance device for changing the movement direction, movement speed and / or oscillation strength of the sand-water mixture is provided in the flushing channel.

[0026] Furthermore, the disturbance device includes a plurality of raised structures and / or recessed structures arranged on the bottom surface and / or side surfaces of the flushing channel, and adjacent raised structures or recessed structures are spaced a certain distance apart.

[0027] Furthermore, the disturbance device includes a plurality of steel bar grids arranged inside the flushing channel, and a certain distance is spaced between two adjacent steel bar grids.

[0028] Furthermore, the density of the steel bar grid mesh near the outlet of the flow device in the flow channel is greater than the density of the steel bar grid mesh at other locations.

[0029] Furthermore, each steel bar grid mesh includes transverse steel bars and longitudinal steel bars. The longitudinal steel bars of two adjacent steel bar grid meshes are staggered in height, and the transverse steel bars of two adjacent steel bar grid meshes are staggered in the width direction of the flow device.

[0030] Furthermore, the disturbance device includes a plurality of sheet-shaped, spiral-shaped, knife-shaped, triangular and / or columnar disturbers arranged inside the rushing flow channel, wherein:

[0031] The disturber is fixedly arranged, or the disturber actively moves under the drive of the power device, or the disturber passively follows the movement under the impact of the sand-water mixture.

[0032] Furthermore, the disturbance device includes a mechanical vibrator arranged inside the flow channel for changing the oscillation intensity of the sand-water mixture and / or an accelerator for increasing the flow speed of the sand-water mixture.

[0033] Furthermore, the bottom and side surfaces of the flushing channel are covered with wear-resistant materials.

[0034] The present invention has the following beneficial effects:

[0035] The sea sand purification system of the present invention is provided with a flushing device so that the sand-water mixture formed by fully mixing sea sand and water flows in the flushing channel. Through repeated strong collisions and friction between sea sand and sea sand, sea sand and water, and sea sand and the inner wall of the flushing device, the film layer of harmful substances on the surface of the sea sand is gradually peeled off and enters the water, thereby achieving the effect of completely removing harmful substances such as chloride ions on the surface of the sea sand. At the same time, the sea sand continuously collides during the flushing process, and the speed and direction are constantly changing. Through the relative impact of the sea sand and water, the harmful substances in the fine cracks are quickly exchanged with the water outside, and the harmful substances in the fine cracks enter the water and are removed. Finally, the sand and water are separated by a sand-water separation device, and the harmful substances removed from the sea sand and entering the water are discharged together with the water.

[0036] The present invention can fully remove harmful substances from the surface of sea sand and within fine cracks and pores, restoring the sea sand to its pre-seabed state, making it safe for use like river sand. The purified sea sand does not cause corrosion of concrete reinforcement or concrete degradation, and has the advantages of good durability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figures 1-8 Schematic diagrams of different specific implementations of the flow device in the present invention;

[0038] Figure 9 Schematic diagram of how the relative impact force between sea sand and water flow removes harmful substances from the cracks and pores of the sea sand;

[0039] Figure 10 is a schematic diagram of a steel bar grid;

[0040] Figure 11 is a perspective view of an embodiment of the sea sand purification system of the present invention;

[0041] Figure 12 for Figure 11 A top view of

[0042] Figure 13 is a perspective view of another embodiment of the sea sand purification system of the present invention;

[0043] Figure 14 for Figure 13 A top view of

[0044] Figures 15-23 Schematic diagrams of different specific implementations of sea sand purification systems using positive pressure pushing force and negative pressure suction force;

[0045] Figure 24 This is a diagram showing the precipitation of chloride ions in distilled water after Xiyuanxi River sand from Tong'an, Xiamen was soaked in salt water for 180 days;

[0046] Figure 25 This is a graph showing the chloride ion precipitation of raw sea sand from Tongan Bay, Xiamen, when immersed in distilled water over time;

[0047] Figure 26 This figure shows the comparative experimental results of concrete made from sea sand and river sand purified by the system of the present invention;

[0048] Figures 27-33 Schematic diagram of different specific implementation methods of the perturbator. DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0050] The inventors have found that the salt content in general seawater is between 3% and 5%. These salts are mainly inorganic salts such as sodium chloride, magnesium chloride, calcium chloride, magnesium sulfate, and calcium sulfate. These inorganic salts mainly exist in seawater in ionic state. In addition, there are also a large number of microorganisms, algae, secretions of marine animals and plants, organic matter, mud, etc. in seawater.

[0051] Weathered rocks are transported to the ocean and deposited to form sea sand. Long-term immersion in seawater causes the aforementioned harmful substances (inorganic salts, microorganisms, algae, secretions of marine plants and animals, organic matter, mud, etc.) to coexist and grow or deposit on the surface of the sea sand and in its cracks and pores. When the amount of these harmful substances grows, adsorbs, or deposits reaches a certain level, a thin layer forms on the surface of the sea sand, enveloping it. This thin layer is a blend of various substances, some of which are active, such as microorganisms, while others are sticky. These substances, coexisting and accumulating on the sand's surface, have a certain degree of adhesion to the sand. These harmful substances, like a film (because they are a multi-substance accumulator with a certain degree of adsorption, forming a thin, film-like layer, can be called a multi-molecular film), covering the sand's surface.

[0052] The harmful substance film on the surface of sea sand is the main reason why it is difficult to effectively purify sea sand using the original washing method. The existence of the film hinders the hydration reaction between sea sand and cementitious materials (cement, etc.), reducing the bonding strength between sea sand and cementitious materials. This is also one of the important reasons for the corrosion of steel bars and the deterioration of concrete. The specific analysis is as follows:

[0053] 1. Chloride salts in sea sand can be divided into two parts according to the difficulty of removal. One part is simply adsorbed on the outer surface of the sand body. Because chloride salts are easily soluble in water and dissolve quickly, this part of chloride salts can be easily removed by quickly dissolving in water. For example, river sand or purified sea sand that has been purified to a chloride ion content of 0.000% is soaked in salt water for 180 days to obtain sand containing chloride salts (chloride salts are simply adsorbed on the outer surface of the sand body). When this sand is soaked in distilled water, the chloride salts can be completely dissolved in the water within a few minutes and quickly reach a state of equilibrium. If the sand and water are separated, the chloride salts can be discharged along with the water. The precipitation of chloride ions in water by river sand containing chloride salts is as follows: Figure 24 The other part is chloride salts that are difficult to remove. These chloride salts are deposited together with other harmful substances in the film layer on the surface of the sea sand, in the fine cracks and pores of the sand body. The existence of this film layer on the surface of the sea sand blocks the passage of chloride ions in the film layer and in the film layer (including in the fine cracks and pores) to dissolve in water. The chloride ions precipitate slowly. When soaked at room temperature, it takes a long time for the chloride ions to slowly precipitate and dissolve in water to reach the equilibrium value. According to tests, this time is as long as 24-72 hours. Figure 25 shown.

[0054] Second, the presence of this film layer reduces the chemical activity of hydration between the sea sand surface and cement and other binders, hindering or reducing the chemical bonding between the sea sand and the binder (cement, etc.). The presence of this film layer leads to a decrease in the degree of hydration and a weakened chemical bond between the sea sand and the binder. When this incompletely purified sea sand is made into mortar or concrete, the poor chemical bonding between the sand and the binder over time, due to various factors such as thermal expansion and contraction, weakens the bond between the sand and the binder. The sand and the binder separate, forming gaps, leading to a gradual decrease in the strength and deterioration of the concrete and mortar. These gaps between the sand and the binder allow air to penetrate, leading to carbonization and accelerating the corrosion of rebar.

[0055] 3. The film layer adsorbed on the surface of the sea sand is active and sticky, with strong adsorption capacity and a certain bonding force with the sea sand. Therefore, ordinary washing methods cannot separate this film layer from the sea sand. They can only clean and remove mud, inorganic salts (chloride salts), and other harmful substances outside the film layer. Unremoved chloride ions in and from the film layer will continue to precipitate, resulting in the continuous detection of chloride ions over time. As a result, the chloride ions continuously precipitated after the sea sand cleaned by the washing method is used in construction can cause corrosion of steel bars.

[0056] In summary, besides chloride ions, which cause steel corrosion, harmful substances in sea sand also include other harmful substances on the sand's surface that degrade concrete. These harmful substances form a film layer on the sand's surface, and some are deposited within the sand's cracks and pores. The presence of this film layer makes it difficult to effectively remove harmful substances from sea sand using simple washing methods. Because of the obstruction of the film layer, conventional washing methods result in the continuous precipitation of chloride ions from the cleaned sea sand, making it difficult to effectively remove chloride salts from the sand, causing steel corrosion. Furthermore, the film layer hinders the full hydration of the cementitious material and the formation of a chemical bond between the sea sand and the cementitious material, leading to a series of concrete degradation problems and steel corrosion, and accelerating concrete aging.

[0057] Therefore, in order to prevent the corrosion of concrete reinforcement and the deterioration of concrete, it is necessary to effectively remove the chloride ions and harmful substance film in the sea sand. In the present invention, effective removal does not mean completely removing the harmful substances, but means that the content of harmful substances such as chloride ions in the sea sand is less than the prescribed value, so that the properties of the purified sea sand are in the same basic state as river sand.

[0058] The inventors made further important discoveries through further research. They found that the various harmful substances in sea sand will not react chemically with the sand body of the sea sand. Therefore, as long as the bonding force between the film layer and the surface of the sea sand is destroyed by physical methods, this film layer can be removed, so that the chloride salts and other harmful substances on the surface of the sea sand and in the fine cracks can be effectively removed, and the sea sand can be restored to the state of river sand.

[0059] Based on the above findings of the inventor, the embodiment of the present application provides a sea sand purification system, as shown in the figure, which comprises a current breaker 1 and a sand-water separation device 18. Figures 1-33 The current breaker 1 comprises an inlet 2 and an outlet 3, and the inlet 2 and the outlet 3 are connected by a current flow channel 4.

[0060] The inlet 2 of the current breaker 1 is used for adding a sand-water mixture formed by fully mixing sea sand and water, the current flow channel 4 is used for making the sand-water mixture flow in the current flow channel 4 from the inlet to the outlet at a certain current flow speed, and the outlet 3 of the current breaker 1 is used for discharging the sand-water mixture.

[0061] The sand-water separation device 18 is arranged at the outlet 3 of the current breaker 1, and is used for sand-water separation on the sand-water mixture discharged from the outlet 3 of the current breaker 1, so as to discharge the harmful substances removed from the sea sand into the water together with the water.

[0062] The use method of the present application comprises:

[0063] S1: adding a sand-water mixture formed by fully mixing sea sand and water into the inlet of the current breaker 1, wherein the current breaker 1 comprises an inlet 2 and an outlet 3, and the inlet 2 and the outlet 3 are connected by a current flow channel 4.

[0064] In the present application, the fully mixing of sea sand and water means that after the sea sand is mixed with water, the sea sand is dispersed and suspended in the water to form a suspension, and the sea sand and water cannot be layered (the sea sand is deposited in the lower layer and the water is in the upper layer). In order to keep the sea sand in suspension in the water without deposition, a power is needed, which can be the impact force of the water flow itself or the power externally applied to keep the water flow impacting. Under the action of the impact force of the water flow and / or the external force, the sea sand is in a suspended state in the water to form a suspension.

[0065] The suspension can be a complete suspension, in which the sea sand is completely suspended in the water. It can also be a partial suspension, in which a small amount of sea sand is allowed to deposit at the bottom, but the deposited sea sand is not stationary for a long time after deposition, but is always in a state of sliding and jumping. The specific reason is that the relatively coarse sand particles will sink, impact the bottom surface, and then be suspended upward under the impact of water. The process is constantly changing up and down and left and right, and is not in a state of deposition without movement.

[0066] The sea sand purification system of the present application further comprises a conveying device, which can be used to add the sand-water mixture into the inlet of the current breaker, or the conveying device can also be used to add the sea sand and water into the inlet of the current breaker, and the specific implementation mode is as follows:

[0067] 1. The sea sand is added into the inlet 2 of the current flow device 1 by the working of the conveying device 17, which can be a sand-water conveyor, a belt conveyor, a bucket elevator, a wave baffle belt conveyor or a loader, and water is added into the inlet 2 of the current flow device 1 through a pipeline at the same time, and the sea sand and water are fully mixed in the inlet 2 of the current flow device 1 to form a sand-water mixture.

[0068] 2. The sea sand and water are mixed in other devices outside the current flow device 1 to form a sand-water mixture, and then the sand-water mixture is added into the inlet 2 through a pipeline or the like.

[0069] In the present application, the amount of water in the sand-water mixture formed by fully mixing the sea sand and water should not be too small, and the reasons are as follows:

[0070] In the present application, the film layer on the surface of the sea sand is removed by repeatedly colliding and rubbing between the sea sand and the sea sand, between the sea sand and the water, and between the sea sand and the inner wall of the current flow device in the process of current flow. To achieve the repeated collision of the sea sand, the sea sand should be fully mixed with the water to form a suspended state in the water, so that each sea sand particle can move in multiple directions to collide sufficiently.

[0071] When the amount of water is too small, the sea sand cannot form a suspended state in the water, and the sea sand cannot move in multiple directions in the water, which is manifested in the overall slow sliding of the sea sand, the collision of the sea sand is very small, and the impact is low, which is not conducive to stripping the harmful substances on the surface.

[0072] Therefore, the amount of water should be at least to submerge the upper surface of the sea sand and have a certain amount of surplus to ensure that the sea sand is immersed in the water and can be fully moved and collided in the water.

[0073] The sea sand has voids when naturally piled up, and the amount of water in the sand-water mixture should be at least to fill the voids when the sea sand is naturally piled up and have a certain amount of surplus to ensure that the sea sand is immersed in the water. Generally, the mass ratio of sea sand to water should be no more than 2.5:1.

[0074] S2: The sand-water mixture is flowed in the current flow channel 4 from the inlet 2 to the outlet 3 at a certain current flow speed, and the selection of the current flow speed should ensure that the sand-water mixture is fully mixed with the sea sand and water in the process of current flow to avoid the deposition of the sea sand.

[0075] In the process of current flow, the sea sand and the sea sand, the sea sand and the water, and the sea sand and the inner wall of the current flow device collide and rub with each other to strip the harmful substances on the surface of the sea sand into the water; at the same time, the relative speed of the sea sand and the water is different, so that the harmful substances in the sea sand fine cracks enter the water by exchanging with the water, and the specific process is analyzed as follows:

[0076] Since the sea sand cannot chemically react with the substances in the sea, the binding force between the film layer adsorbed on the surface of the sea sand and the sea sand is physical adsorption, so the binding force between the film layer and the sea sand can be destroyed by physical means, and the film layer on the surface of the sea sand can be removed.

[0077] The physical means for destroying the binding force between the film layer and the sea sand is impact friction, and the specific operation is as follows: sea sand and an appropriate amount of water are added to the inlet of the flow er, and the sand-water mixture flows from the inlet to the outlet in the flow er. During the flow, the surface shape and particle size of the sea sand are different, and the movement trajectory of the sea sand in the sand-water mixture due to the action of various forces is irregular, resulting in repeated impact and friction between the sea sand and the sea sand, and repeated impact and friction between the sea sand and water and the inner wall of the flow er, and the speed, direction and impact force of the sea sand in the flow er are constantly changing.

[0078] When the impact, impact force and friction force are greater than the adsorption force between the harmful substance film layer on the surface of the sea sand and the surface, the harmful substance film layer on the surface of the sea sand will gradually peel off and fall off the surface of the sea sand into the water, achieving the effect of removing the harmful substance film layer on the surface of the sea sand.

[0079] Although the harmful substance film layer on the surface of the sea sand is removed by impact friction, there is still harmful substance deposited and adsorbed in the fine gap and pore of the sea sand, and the harmful substance in the fine gap and pore of the sea sand cannot be removed by direct impact and friction.

[0080] However, during the flow, due to the different masses of water and sea sand, the relative speed of the sea sand and water is different, and the movement speed and direction of the sand body are constantly changing, the speed, direction and impact force of the sea sand in the flow er are constantly changing, these factors will accelerate the exchange of harmful substances in the fine gap with the outside water, and accelerate the harmful substances in the fine gap of the sea sand into the water.

[0081] Specifically, as shown in Figure 9 After the harmful substance film layer on the surface of the sea sand 10 is removed, the fine gap and pore 11 on the water-facing surface of the sea sand 10 bear the positive pressure impact and scour of the water flow 12, the harmful substances 13 in the fine gap and pore 11 are subjected to high-speed impact of the front water flow and are repelled out of the fine gap and pore 11 of the sea sand. The backwater surface of the sea sand 10 produces a relative negative pressure area 14, and the fine gap and pore 15 on the backwater surface of the sea sand produce a negative pressure suction flow under the action of the pressure difference, and the harmful substances 16 in the fine gap and pore 15 of the sea sand are passively sucked out under the action of the pressure difference of the negative pressure suction flow, and are separated from the fine gap and pore of the sea sand and enter the water, achieving the effect of effectively removing the harmful substances in the fine gap and pore of the sea sand.

[0082] The present invention requires that the sea sand and water should be fully mixed during the entire process of the sand-water mixture to ensure that the sea sand is suspended in the water. To achieve this requirement, it is necessary to ensure that the amount of water used is not less than the aforementioned requirements, and it is also necessary to ensure that the speed of the sand-water mixture flowing in the flushing device is not too low. The reasons are as follows:

[0083] When the amount of water reaches the requirement, sea sand can be suspended in the water. However, the specific gravity of sea sand is greater than that of water. The sea sand suspended in the water has a tendency to settle downward. The sinking of sea sand can easily lead to stratification of sea sand and water.

[0084] When sea sand and water are separated into layers, the sea sand cannot move fully in the water. Overall, the water flows downward in the upper layer, and the sea sand slides downward in the lower layer. There are few collisions between the sea sands, which reduces the efficiency of stripping harmful substances from the surface.

[0085] Therefore, the flow velocity should be selected so that the sand and water mixture can be fully mixed during the flow process, ensuring that the sea sand is suspended in the water and preventing the sea sand from settling. Generally, the flow velocity of the sand and water mixture should not be less than 1.5m / s.

[0086] S3: The sand-water mixture is discharged from the outlet 3 of the flusher 1, and the discharged sand-water mixture is separated into sand and water by a sand-water separation device, and the harmful substances removed from the sea sand and entering the water are discharged together with the water.

[0087] After the harmful substance film on the surface of the sea sand and the harmful substances deposited and adsorbed in the fine cracks and pores of the sea sand are fully and effectively removed, the sand-water mixture is discharged from the outlet 3 of the flusher 1. The discharged sand-water mixture is separated from the sand and water by the sand-water separation device, and the harmful substances entering the water are discharged together with the water, thereby achieving the purpose of removing chloride ions and other harmful substances in the sea sand, realizing the purification of the sea sand, and restoring the sea sand to the state of river sand.

[0088] In the present invention, the sand-water separation device 18 can be a sand-water separator. After the sand-water mixture is discharged from the outlet 3 of the flushing device 1, it is separated from the water by the sand-water separator 18, and the harmful substances removed from the sea sand and entering the water are discharged together with the water. Figure 13 、 14 shown.

[0089] The selection of the sand-water separator must meet the effect of sand-water separation. The sand-water separator can be a bucket wheel sand-water separator, a linear screen sand-water separator, etc., and the present invention does not limit it.

[0090] The present invention can also be provided with a dehydration device 19 after the sand-water separation device 18, and the dehydration device is used to dehydrate the sea sand after the sand-water separation. Figure 11 、 12As shown, after the sand-water mixture is discharged from the outlet 3 of the flushing device 1, it passes through the sand-water separator 18 for sand and water separation, and is further dehydrated by a dehydration device 19 such as a linear vibrating screen and the sea sand is transferred by the transfer conveyor 20, and the harmful substances removed from the sea sand and entering the water are discharged together with the water.

[0091] The sea sand purification system of the present invention is provided with a flushing device so that the sand-water mixture formed by fully mixing sea sand and water flows in the flushing channel. Through repeated strong collisions and friction between sea sand and sea sand, sea sand and water, and sea sand and the inner wall of the flushing device, the film layer of harmful substances on the surface of the sea sand is gradually peeled off and enters the water, thereby achieving the effect of completely removing harmful substances such as chloride ions on the surface of the sea sand. At the same time, the sea sand continuously collides during the flushing process, and the speed and direction are constantly changing. Through the relative impact of the sea sand and water, the harmful substances in the fine cracks are quickly exchanged with the water outside, and the harmful substances in the fine cracks enter the water and are removed. Finally, the sand and water are separated by a sand-water separation device, and the harmful substances removed from the sea sand and entering the water are discharged together with the water.

[0092] The present invention can fully remove harmful substances from the surface of sea sand and within fine cracks and pores, restoring the sea sand to its pre-seabed state, making it safe for use like river sand. The purified sea sand does not cause corrosion of concrete reinforcement or concrete degradation, and has the advantages of good durability and low cost.

[0093] The chloride ion content of raw sea sand is typically 0.15%. After purification using the present invention, sampling and testing of the purified sea sand revealed that the chloride ion content in the sand can be reduced to between 0.000% and 0.002%, far below the standard specified in JG / T494-2016, "Purified Sea Sand for Construction and Municipal Use." Other harmful substances are effectively removed along with the chloride ions, bringing the purified sea sand to the basic state of river sand. Multiple sampling tests revealed chloride ion contents of 0.001%, 0.001%, 0.001%, 0.001%, 0.0004%, 0.0013%, and 0.000%, respectively. The specific sampling and testing results are shown in Table 1 below.

[0094] Table 1: Summary of sampling and testing of purified sea sand produced by the sea sand purification system of the present invention

[0095] Sample No. Modulus Shell Content (%) Silt Content (%) Chloride Content (%) 1 3.1 1.8 0.5 0.001 2 2.9 1.8 0.2 0.001 3 2.7 2.0 0.4 0.001 4 2.9 2.8 0.6 0.001 5 2.8 0.4 0.0004 6 0.0013 7 2.1 1.2 0.2 0.000

[0096] After three years of testing, the performance indicators of the concrete made from the purified sea sand and high-quality river sand were close to each other, such as Figure 26 shown.

[0097] In the present invention, the length of the flusher 1 should ensure that the harmful substance film on the surface of the sea sand and the harmful substances deposited and adsorbed in the fine cracks and pores of the sea sand are fully and effectively removed. When the space inside the factory building is large enough or no factory building is required, a longer, integrated single-stage flusher can be used to remove harmful substances from the sea sand.

[0098] However, in practice, when setting up a factory building, the space of the general factory building is difficult to meet the requirements of the overall single-stage flow device. To solve this problem, the flow device 1 is set as a multi-stage flow device for combined use in the present invention, and the number of stages of the flow device can be 2, 3, 4, 5, 6, 7, etc.

[0099] When the flusher is a multi-stage flusher used in combination, a sand-water separation device is provided at the outlet of several stages of flushers including the last stage.

[0100] A sand-water separation device can be set at the outlet of each stage of the flow device. When in use, each stage of the flow device executes S1-S3 once, that is, each stage of the flow device performs sand-water separation.

[0101] It is also possible to set up a sand-water separation device only at the outlet of the last stage of the flow device. When in use, the last stage of the flow device executes S1-S3 once, and each stage of the flow device before it only executes S1-S2 once, that is, sand and water separation is only performed in the last stage of the flow device.

[0102] A sand-water separation device can also be set at the outlet of the last-stage flow device and the previous several-stage flow devices. When in use, the last-stage flow device and the previous several-stage flow devices execute S1-S3 once, and each of the other-stage flow devices only executes S1-S2 once, that is, sand and water separation is performed in the last-stage flow device and the previous several-stage flow devices.

[0103] When a dehydration device is also provided, the dehydration device is provided in the same manner as the sand-water separation device, and the dehydration device is provided after the sand-water separation device.

[0104] The water used in the present invention can be tap water, lake water, river water, collected rainwater, desalinated seawater or recycled water, etc. To save water resources, if the production line is built near a sewage treatment plant, the water used in the present invention can also be water treated by the sewage treatment plant and ready for discharge. If the production line is built at the seaside, the purified water can partially use seawater.

[0105] The sea sand purification system of the present invention may further include a waste screening machine, which is arranged before the inlet 2 of the flushing device 1 and is used to screen out coarse particles of waste in the sea sand.

[0106] After the raw sea sand is tested, it is mixed as required and then enters the waste screening machine, through which mud blocks, shells and other coarse particles larger than 5mm in the sea sand are screened out.

[0107] The present invention does not limit the specific shape of the flushing device 1, as long as it can achieve the flushing of the sand-water mixture. Several examples are given below:

[0108] Example 1:

[0109] In this example, the shape of the flushing channel 4 of the flushing device 1 is a groove with an upper opening, and its cross section can be rectangular, trapezoidal, U-shaped, semicircular, diamond-shaped, etc. The upper opening of the flushing channel 4 can be fully open or partially open, such as Figures 1-6 shown.

[0110] The flushing channel 4 is arranged obliquely, the top end of the flushing channel 4 is the inlet 2 of the flushing device 1, and the bottom end is the outlet 3 of the flushing device 1.

[0111] The sand-water mixture in the flushing channel 4 flushes from the inlet 2 at the top to the outlet 3 at the bottom. The power of the flushing flow can be one or more of natural gravity, water impact force, and mechanical power.

[0112] The natural gravity is provided by the inclination of the flushing channel 4, and the inclination angle of the flushing channel 4 cannot be too small. Since the sand-water mixture needs to flow downward at a certain flushing speed, when the inclination angle of the flushing device is too small, the flushing speed of the sand-water mixture cannot meet the requirement or the flushing cannot be carried out, which is not conducive to the removal of harmful substances on the surface of the sea sand.

[0113] If the inclination angle of the flushing channel 4 is too small, if you want to increase the flow speed of the sand-water mixture, you must increase the power. If too much power is applied, the sand-water mixture will splash and overflow from the upper opening of the flow channel 4. Therefore, the inclination angle of the flushing channel 4 cannot be too small. Generally, the inclination angle range of the flushing channel 4 is [2°, 90°].

[0114] When water or sand-water mixture is added into the inlet 2 of the flushing device 1, a certain speed can be provided for the water or sand-water mixture, so that the water or sand-water mixture has a certain impact force, providing a certain power for the flow of the sand-water mixture in the flushing channel 4.

[0115] The mechanical power is the power provided by a mechanical device arranged in the flushing channel 4 and / or at the inlet 2. For example, a driven chain scraper is arranged in the flushing channel 4 to provide a certain power for the flushing of the sand-water mixture.

[0116] In this example, a splash-proof top cover can be provided on the upper opening of the flushing channel 4 to prevent the sand-water mixture from splashing out of the flusher.

[0117] Example 2:

[0118] In this example, the shape of the flushing channel 4 of the flushing device 1 is a tubular shape with closed sides, and its cross section can be rectangular, circular or other closed shapes, etc., and the present invention does not limit this. Figure 7 、 8 shown.

[0119] The flushing channel 4 can be arranged horizontally, inclined, or vertically. One end of the flushing channel 4 is the inlet 2 of the flushing device 1, and the other end is the outlet 3 of the flushing device 1.

[0120] The sand-water mixture in the flushing channel 4 flushes from the inlet 2 to the outlet 3, and the power of the flushing flow can be one or more of natural gravity, positive pressure pushing force, negative pressure suction force, and mechanical power.

[0121] The flushing channel 4 of this example is not an open structure, but a side-closed structure, so the flushing of the sand-water mixture can be achieved by pressure. The pressure can be a negative pressure suction force applied from the outlet 3 of the flusher 1 or a positive pressure pushing force applied from the inlet 2 of the flusher 1 to the outlet 2 of the flusher 1, or a combination of the two.

[0122] In this example, the positive pressure pushing force can be provided by a sand pump, and the negative pressure suction force can be provided by a jet pump or a sand suction pump.

[0123] Several ways to achieve positive pressure push force are as follows:

[0124] 1. The sand-water mixture in the sand-water pool 21 at the entrance is pumped into the inlet 2 of the flushing device 1 by the sand pump 22. The sand pump 22 uses the positive pressure to push the sand-water mixture to the outlet 3 of the flushing device 1 and into the sand-water pool 24 at the outlet. Figure 15 shown.

[0125] 2. The sand-water mixture in the sand-water pool 21 at the entrance is pumped into the inlet 2 of the flusher 1 by the sand pump 22. The sand pump 22 uses the positive pressure to push the sand-water mixture to the outlet 3 of the flusher 1, directly enters the inlet 2 of the next-level flusher 1 and flushes to the outlet 3. The sand-water mixture discharged from the outlet 3 of the flusher 1 is then separated from the sand and water by the sand-water separator 18, and the harmful substances removed from the sea sand and entered into the water are discharged together with the water. The separated sea sand enters the sand-water pool 24 at the outlet. Figure 16 、 17 shown.

[0126] 3. The sand-water mixture in the sand-water pool 21 at the entrance is pumped into the inlet 2 of the flushing device 1 by the sand pump 22. The sand pump 22 uses the positive pressure to push the sand-water mixture to the outlet 3 of the flushing device 1 and enters the transition container 23. The sand-water mixture discharged from the transition container 23 passes through the inlet 2 of the next-level flushing device 1 and flows to the outlet 3 at a certain flushing speed. Then, the sand and water are separated by the sand-water separator 18 and enter the sand-water pool 24 at the outlet. Figure 18 shown.

[0127] The negative pressure suction force is achieved as follows:

[0128] The sand-water mixture in the sand-water pool 21 is sucked to the inlet 2 of the flushing device 1 by the jet pump or the sand suction pump 25. The jet pump or the sand suction pump uses the negative pressure suction force to suck the sand-water mixture to the outlet 3 of the flushing device 1. The sand-water mixture discharged from the outlet 3 of the flushing device 1 is then separated from the sand and water by the sand-water separator 18. Figures 19-21 As shown, harmful substances removed from sea sand and entering the water are discharged together with the water.

[0129] The positive pressure pushing force and negative pressure suction force can be used alone or in combination in each stage of the flow device (such as Figure 22 as shown) or used in combination in a multi-stage flow device (as Figure 23 until the harmful substances in the sea sand are lower than the set value.

[0130] And when the flushing channel 4 is inclined or vertically set, and when the top of the flushing channel 4 is the inlet 2 of the flusher 1 and the bottom is the outlet 3 of the flusher 1, the sand and water mixture can flow from the inlet 2 to the outlet 3 under the action of gravity.

[0131] Similarly, this example can also achieve rushing flow through mechanical power.

[0132] In the above two examples, the structure of the flushing channel can be a combination of one or more of a straight line, a broken line, a curved line, a spiral line, and a convoluted line.

[0133] The present invention does not limit the material of the flow device, and it can be made of metal, non-metal, wood, inorganic, organic, concrete or other mixed materials, etc. Since sea sand frequently collides and rubs against the inner wall of the flow device, to protect the inner wall of the flow device, wear-resistant material such as granite or wear-resistant bricks can be attached to the bottom and side surfaces of the flow device.

[0134] As an improvement to the embodiment of the present invention, Figures 3-6As shown in Figures 8 and 9, the present invention includes a disturbance device within the flushing channel 4 for changing the direction, speed, and / or oscillation intensity of the sand-water mixture. There may be multiple disturbance devices, which may be spaced at varying intervals. However, the placement of the disturbance device should ensure that the sand-water mixture in the flushing device 1 flows smoothly at a predetermined speed.

[0135] During the flushing process, the presence of the disturbance device alters the direction, trajectory, speed, and oscillation and splashing force of the sand-water mixture. This increases the frequency and force of friction between sand and sand, between sand and water, and between sand and the inner wall of the flushing device within the flushing channel. Furthermore, friction between sand and the disturbance device also impacts and rubs against each other, subjecting the entire surface of the sand to more comprehensive impact and friction, making it easier to remove harmful substances from the sand's surface. Furthermore, the disturbance device changes the speed and direction of the sand and water flow, making it easier to remove harmful substances from the fine pores in the sand in all directions.

[0136] The present invention does not limit the specific structural form of the disturbance device. Several specific implementations are given below. These disturbance devices can be used alone or in combination.

[0137] 1. The disturbance device includes a plurality of raised structures 5 and / or recessed structures arranged on the bottom surface and / or side surface of the flow impactor 1, and adjacent raised structures 5 or recessed structures are spaced a certain distance apart.

[0138] Taking the raised structure 5 as an example, the mixture of water flow and sea sand collides and splashes under the obstruction of the raised structure 5, which also causes the sand to be suspended in the water, thereby changing the movement speed and direction of the sea sand and water flow. The mixture of water flow and sea sand repeatedly impacts, bounces and falls on the bottom surface of the flusher, making the friction and collision of the sea sand more frequent and stronger, thereby accelerating the removal of harmful substances in the sea sand.

[0139] Sea sand frequently collides and rubs against the raised and / or recessed structures. To increase the service life of the raised and / or recessed structures, the raised and / or recessed structures can be made of metal materials such as steel, stone, brick, plastic, concrete, and other metal or non-metal materials. When the raised and / or recessed structures are made of stone, the raised and / or recessed structures can be integrated with the wear-resistant stone slab.

[0140] 2. The disturbance device may include a plurality of steel grids 6 arranged inside the flow flusher 1 , with a certain distance between two adjacent steel grids 6 . The mixture of water flow and sea sand changes its trajectory under the obstruction of the steel grids 6 .

[0141] In addition, the density of the steel grille near the outlet of the flushing device in the flushing channel is greater than the density of the steel grille at other locations, which reduces the speed at which the sand-water mixture enters the sand-water separation equipment, reduces the impact force of the sand-water mixture when entering the sand-water separation equipment, and prevents sand and water from splashing.

[0142] Each steel grid 6 includes transverse reinforcement 7 and longitudinal reinforcement 8. The longitudinal reinforcements of two adjacent steel grids are staggered regularly or irregularly in height, and the transverse reinforcements of two adjacent steel grids are staggered regularly or irregularly across the width of the flow device, so that the trajectory and speed of the water and sea sand mixture are repeatedly changed. Multiple steel grids can also be connected together by continuous reinforcement 9 on both sides.

[0143] Steel gratings can be divided into two types: the first type, where the bottom row of transverse steel bars aligns with the bottom surface of the flow device, and the second type, where the bottom row of transverse steel bars is spaced a certain distance from the bottom surface of the flow device.

[0144] The first type of steel grid mesh and the second type of steel grid mesh are staggeredly arranged inside the flusher. When in use, the sand and water mixture is blocked by the steel grid mesh and hits the lower horizontal steel bars of the first type of steel grid mesh, generating parabolic motion. The thrown sand and water mixture hits the lower horizontal steel bars of the second type of steel grid mesh that are higher than the bottom surface of the flusher. At the same time, under the obstruction of the vertical steel bars staggered in the vertical arrangement of the first type of steel grid mesh and the second type of steel grid mesh, the sea sand in the sand and water mixture collides and rubs against each other due to the interception resistance, and collides and rubs against the vertical steel bars.

[0145] 3. The disturbance device includes a plurality of sheet-shaped, spiral-shaped, knife-shaped, triangular and / or column-shaped disturbers arranged inside the flow channel 4, such as Figures 27-33 As shown. However, these shapes are not limited to these. Any device that can change the speed or direction of sand and water movement, or increase or change the frequency or force of sand impact and friction, is considered a disturbance device as described in the present invention. The disturbance device can be used in combination of one or more devices. When multiple devices are used, adjacent two disturbance devices are spaced a certain distance apart.

[0146] More preferably, the disturber can be arranged in a staggered manner, but it can also be arranged in a non-staggered manner.

[0147] The disturber can be fixedly set to change the movement trajectory of the sand-water mixture through the shape of the disturber itself.

[0148] The disturber can also move actively under the drive of the power device, and change the movement direction and speed of the sand-water mixture through active mechanical disturbance.

[0149] The disturbers can also move passively following the impact of the sand-water mixture, and change the moving direction and speed of the sand-water mixture by passive disturbance.

[0150] 4. The disturbance device comprises a mechanical vibrator arranged inside the flow channel, for changing the oscillation intensity of the sand-water mixture. The mechanical vibrator can be one or more, and when there are multiple, the adjacent two are arranged at a certain distance.

[0151] For example, the mechanical vibrator can be a vibration exciter.

[0152] 5. The disturbance device comprises an accelerator arranged inside the flow channel, for increasing the flow speed of the sand-water mixture. The accelerator can be one or more, and when there are multiple, the adjacent two are arranged at a certain distance.

[0153] For example, the structure of the accelerator can be the same as that of the disturbers shown in Figure 27 、 29 , 31, 33, and the disturbers shown in Figure 27 、 29 , 31, 33 are driven by the power device to rotate actively, and when the rotating speed is greater than the flow speed of the sand-water mixture, it plays the role of the accelerator.

[0154] The above is the preferred embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A sea sand purification system, characterized in that: Including flushing device and sand-water separation device; The flushing device includes an inlet and an outlet, wherein the inlet and the outlet are connected by a flushing channel, the inlet is used to add a sand-water mixture formed by fully mixing sea sand and water, the flushing channel is used to allow the sand-water mixture to flow from the inlet to the outlet at a certain flushing speed in the flushing channel, and the outlet is used to discharge the sand-water mixture; The sand-water separation device is arranged at the outlet of the flusher, and is used to separate the sand-water mixture discharged from the outlet of the flusher, and discharge the harmful substances removed from the sea sand and entering the water together with the water; The amount of water in the sand-water mixture should at least fill the gaps in the natural accumulation of sea sand to ensure that the sea sand is immersed in water; the flow rate should be selected to ensure that the sand-water mixture maintains sufficient mixing of sea sand and water during the flow process to prevent sea sand from settling; The weight ratio of sea sand to water in the sand-water mixture is not greater than 2.5:1, and the flow velocity of the sand-water mixture is not less than 1.5 m / s; The flushing channel is provided with a disturbance device for changing the movement direction, movement speed and / or oscillation strength of the sand-water mixture; The disturbance device includes a plurality of steel bar grids arranged inside the flushing channel, with a certain distance between two adjacent steel bar grids; The density of the steel grid mesh near the outlet of the flow device in the flow channel is greater than the density of the steel grid mesh at other locations; Each steel grid mesh includes transverse steel bars and longitudinal steel bars. The longitudinal steel bars of two adjacent steel grid meshes are staggered in height, and the transverse steel bars of two adjacent steel grid meshes are staggered in the width direction of the flow device. The steel grid mesh is divided into a first type of steel grid mesh and a second type of steel grid mesh that are spaced apart from each other. The bottom row of transverse steel bars of the first type of steel grid mesh is in contact with the inner bottom surface of the flow device, and the bottom row of transverse steel bars of the second type of steel grid mesh is spaced a certain distance from the inner bottom surface of the flow device.

2. The sea sand purification system according to claim 1, characterized in that: The shape of the flushing channel is a groove with an opening on the upper side. The flushing channel is arranged at an angle. The top end of the flushing channel is the inlet of the flushing device, and the bottom end is the outlet of the flushing device. The sand and water mixture flows from the inlet to the outlet under the action of gravity, water impact force and / or mechanical power.

3. The sea sand purification system according to claim 2, characterized in that: The inclination angle range of the flushing channel is [2°, 90°).

4. The sea sand purification system according to claim 3, characterized in that: A splash-proof top cover is provided on the upper opening of the flushing channel.

5. The sea sand purification system according to claim 1, characterized in that: The shape of the flushing channel is a tube with closed sides. The flushing channel is arranged horizontally, inclined or vertically. One end of the flushing channel is the inlet of the flusher, and the other end is the outlet of the flusher. The sand and water mixture flows from the inlet to the outlet under the action of gravity, positive pressure pushing force, negative pressure suction force and / or mechanical power.

6. The sea sand purification system according to claim 1, characterized in that: The flusher is a single-stage flusher or a multi-stage flusher used in combination. When the flusher is a multi-stage flusher used in combination, the sand-water separation device is provided at the outlets of several stages of flushers including the last stage.

7. The sea sand purification system according to claim 6, characterized in that: A dehydration device is further provided behind the sand-water separation device, and the dehydration device is used to dehydrate the sea sand after the sand-water separation.

8. The sea sand purification system according to claim 1, characterized in that: The sea sand purification system further comprises a waste screening machine, which is arranged before the inlet of the flushing device and is used for screening out coarse waste particles in the sea sand.

9. The sea sand purification system according to claim 1, characterized in that: The sea sand purification system also includes a conveying device; The conveying device is used to add the sand-water mixture into the inlet of the flushing device, or the conveying device is used to add sea sand and water into the inlet of the flushing device.

10. The sea sand purification system according to claim 1, characterized in that: The bottom surface and side surfaces of the flushing channel are covered with wear-resistant materials.

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