Impurity removal device for preparing lightweight aggregate from dredged sediment and preparation method

Abstract

The invention discloses an impurity removal device for preparing lightweight aggregate from dredged sediment and a preparation method, and belongs to the technical field of resource recovery, treatment and utilization. Comprising an outer cylinder, a lower ring and an upper ring are arranged on the inner wall of the lower end of the outer cylinder in parallel, an inner cylinder is arranged between the lower ring and the upper ring, supporting blocks are arranged on the circumference of the outer wall of the inner cylinder and located between the lower ring and the upper ring, an end plate is arranged at the upper end of the outer cylinder, and the upper end of the inner cylinder is rotationally connected to the middle of the end plate; a gear ring is arranged on the outer wall of the portion, below the end plate, of the inner cylinder, an inner ring of the gear ring is fixed to the inner cylinder, a first rotating assembly is arranged on the end plate, a driving gear is arranged at the output end of the first rotating assembly, and the driving gear is connected with the gear ring in a meshed mode; and a plurality of side wall through holes which are uniformly distributed along the circumference are formed in the outer wall of the inner cylinder above the upper ring. According to the technical scheme, the impurity removal effect on the bottom mud is improved, and then the effect that the dredged bottom mud is used for preparing lightweight aggregate is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resource recycling and utilization, and particularly relates to a device for removing impurities from dredged sludge for preparing lightweight aggregate and a preparation method. BACKGROUND

[0002] A large amount of dredged sludge is generated in channel dredging, and the existing treatment method for the dredged sludge is to pile the dredged sludge in low-lying land, beach land and soil pits, etc. However, the dredged sludge has a large amount of mud, a high water content, and is easy to cause secondary pollution to lakes, soil and groundwater under the action of rainwater scouring, and the piling treatment method will occupy a large area of land resources.

[0003] Lightweight aggregate is a man-made or natural porous particle, which can be used to replace ordinary sand and gravel to prepare lightweight concrete, so as to achieve the effects of weight reduction, heat preservation, shock resistance and material saving. It is shown in the prior art that the dredged sludge can be used as one of the raw materials for preparing lightweight aggregate after three pretreatments of removing impurities, dewatering and grinding. Before the dredged sludge is used to prepare lightweight aggregate, the dredged sludge needs to be subjected to the operation of removing impurities, and the effect of removing impurities directly affects the complexity of the subsequent preparation process and the quality of the prepared lightweight aggregate. Therefore, how to improve the effect of removing impurities from the dredged sludge is a problem to be solved. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a device for removing impurities from dredged sludge for preparing lightweight aggregate and a preparation method, so as to improve the effect of removing impurities from the dredged sludge and improve the effect of using the dredged sludge to prepare lightweight aggregate.

[0005] To achieve the above purpose, the present application provides the following technical solutions: The application discloses a device for removing impurities from dredged sludge for preparing light aggregate, which comprises an outer cylinder, a lower ring and an upper ring arranged in parallel on the inner wall of the lower end of the outer cylinder, an inner cylinder arranged between the lower ring and the upper ring, support blocks arranged in a circle on the outer wall of the inner cylinder and located between the lower ring and the upper ring, an end plate arranged at the upper end of the outer cylinder, the upper end of the inner cylinder being rotatably connected to the middle part of the end plate, a gear ring arranged on the outer wall of the inner cylinder below the end plate, the inner ring of the gear ring being fixed to the inner cylinder, a first rotating assembly arranged on the end plate, a drive gear arranged on the output end of the first rotating assembly and meshingly connected with the gear ring, a plurality of side wall through holes arranged in a circle and uniformly distributed on the outer wall of the inner cylinder above the upper ring, a filter plate arranged on the lower inner wall of the inner cylinder, a plurality of bottom through holes arranged on the filter plate, a fixing ring arranged on the outer wall of the lower end of the outer cylinder, the inner ring of the fixing ring being fixed to the outer cylinder, a plurality of support legs arranged on the fixing ring, one end of each support leg being fixed to the fixing ring, a feeding hopper arranged above the inner cylinder, a fixing rod arranged on the outer wall of the feeding hopper and connecting the feeding hopper to the end plate, and a dilution assembly arranged in the feeding hopper and used for supplying water to the inner cylinder.

[0006] Further, a rotating shaft is symmetrically arranged on the outer surface of the filter plate, one end of the rotating shaft is fixed to the inner plate, the other end of the rotating shaft is rotatably connected to the side wall of the inner cylinder and passes through the side wall of the inner cylinder, a clamping block is arranged on the end of the rotating shaft outside the inner cylinder, the clamping block is located between the upper ring and the lower ring, mounting notches are symmetrically arranged on the upper ring and the lower ring, a rotating column is arranged in each mounting notch, the rotating column is in contact with the mounting notch and can rotate in the mounting notch, a sliding groove is arranged in the middle part of the rotating column and communicates with the space between the upper ring and the lower ring, a connecting shaft is arranged at each end of the rotating column, a stop block is arranged on the outer end of one connecting shaft, and a second rotating assembly is arranged on the outer end of the other connecting shaft and fixed to the outer wall of the outer cylinder.

[0007] Further, a plurality of water supply pipes are arranged in a circle on the side wall of the outer cylinder, the water supply pipes are connected to the outer cylinder, a water distribution cavity is arranged on one end of each water supply pipe between the inner cylinder and the outer cylinder, the water distribution cavity is in communication with the water supply pipe on one side, a water outlet pipe assembly corresponding in number and position to a column of the side wall through holes is arranged on the other side of the water distribution cavity, and the water outlet ends of a plurality of water outlet pipe assemblies are arranged in one-to-one correspondence with a column of the side wall through holes.

[0008] Further, the water supply pipe is slidingly connected to the outer cylinder, a baffle ring is arranged on one end of the water supply pipe outside the outer cylinder, a first spring is arranged between the baffle ring and the outer cylinder, the first spring is sleeved on the water supply pipe, sliding rods are symmetrically arranged on the outer wall of the water distribution cavity, one end of each sliding rod is fixed to the water distribution cavity, the other end of each sliding rod slidingly penetrates the outer cylinder, and a detachable limiting hoop is arranged on one end of each sliding rod outside the outer cylinder, a plurality of guide blocks are arranged on the inner cylinder, the guide blocks are in the shape of a right trapezoid in cross section, and the wide sides of the guide blocks are respectively fixed to the surface of the inner cylinder between the through holes of the adjacent two rows of side walls.

[0009] Further, the water supply pipe is slidingly connected to the outer cylinder, a baffle ring is arranged on one end of the water supply pipe outside the outer cylinder, a first spring is arranged between the baffle ring and the outer cylinder, the first spring is sleeved on the water supply pipe, sliding rods are symmetrically arranged on the outer wall of the water distribution cavity, one end of each sliding rod is fixed to the water distribution cavity, the other end of each sliding rod slidingly penetrates the outer cylinder, and a detachable limiting hoop is arranged on one end of each sliding rod outside the outer cylinder, a plurality of guide blocks are arranged on the inner cylinder, the guide blocks are in the shape of a right trapezoid in cross section, and the wide sides of the guide blocks are respectively fixed to the surface of the inner cylinder between the through holes of the adjacent two rows of side walls.

[0010] Further, the water supply pipe is slidingly connected to the outer cylinder, a baffle ring is arranged on one end of the water supply pipe outside the outer cylinder, a first spring is arranged between the baffle ring and the outer cylinder, the first spring is sleeved on the water supply pipe, sliding rods are symmetrically arranged on the outer wall of the water distribution cavity, one end of each sliding rod is fixed to the water distribution cavity, the other end of each sliding rod slidingly penetrates the outer cylinder, and a detachable limiting hoop is arranged on one end of each sliding rod outside the outer cylinder, a plurality of guide blocks are arranged on the inner cylinder, the guide blocks are in the shape of a right trapezoid in cross section, and the wide sides of the guide blocks are respectively fixed to the surface of the inner cylinder between the through holes of the adjacent two rows of side walls.

[0011] A preparation method of dredged sludge for preparing lightweight aggregate, comprising the following preparation steps: S1, impurity removal of the sludge: removing impurities in the dredged sludge by an impurity removal device; S2, water reduction and drying: separating the mixture in the sediment after impurity removal to obtain the dredged sludge after impurity removal, and transferring the dredged sludge to a drying field for dehydration and drying, so that the final water content is not higher than 12%, and a dried mud block is obtained; S3, crushing and screening: crushing the dried mud block by using a high-speed crusher to obtain uniform fine mud powder, and sealing and moisture-proof storage for standby use; S4, base material compounding: taking the dried mud powder, auxiliary cementing material, alkaline activator, microsilica powder, foaming component and structure stabilizer, adding appropriate amount of water to make the system into a flowable slurry, and uniformly stirring; S5, granulation and foaming: introducing the mixed slurry into a disc granulator or an extrusion granulation device, and synchronously introducing trace gas to form wet granular blank with a particle size of 5-15 mm; S6, static curing: placing the wet granules in a curing chamber for static placement to promote preliminary curing and strength development; S7, heat activation treatment: the pre-cured particles are transferred into a rotary kiln or a box furnace, heated at a constant temperature, and then naturally cooled to obtain lightweight aggregate products with porous interiors and vitrified surfaces.

[0012] The present application has the following advantages: (1) The technical scheme dilutes the dredged sludge with poor fluidity by pumping water into the feeding hopper through the dilution assembly, enhances the fluidity of the dredged sludge, and cleans the dredged sludge adhered to impurities, then starts the first rotating assembly to drive the gear to rotate the gear ring, and then drive the inner cylinder to rotate, in the process of rotating the inner cylinder, part of the diluted dredged sludge is thrown out from the side wall through hole of the inner cylinder to the inner wall of the outer cylinder under the action of centrifugal force, and then is intercepted and collected, and then falls downward, part of the diluted dredged sludge is discharged from the bottom through hole of the filter plate, and then is collected and collected at the lower end of the outer cylinder, so as to realize the separation of the dredged sludge and most of the impurities. (2) In the technical scheme, the dredged sludge is recycled after resource disposal, which can reduce the influence of the dredged sludge on the environment after the river dredging, and the prepared lightweight aggregate can also be used as raw material in various fields of the building industry to meet the use demand of the building industry for aggregate.

[0013] Other advantages, objects, and features of the present application will be set forth in the following specification, and in part will become apparent to those skilled in the art from the present application, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and obtained by the following description. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to make the purpose, technical scheme and beneficial effects of the present application clearer, the present application provides the following drawings for illustration: Figure 1 It is a perspective view of the impurity removal device of the present application; Figure 2 It is a sectional view of the impurity removal device of the present application; Figure 3 It is a perspective view of the internal components of the impurity removal device of the present application; Figure 4 It is a perspective view of the internal components of the impurity removal device of the present application; Figure 5 It is a perspective view of the rotating column provided on the lower ring and the upper ring of the impurity removal device of the present application; Figure 6 It is a perspective view of the rotating column provided on the lower ring and the upper ring of the impurity removal device of the present application; Figure 4 Figure 7 ​Figure 2 is a sectional view of the water outlet pipe assembly of the impurity removal device of the present application.

[0015] The reference signs in the drawings are as follows: 1, outer cylinder; 2, lower ring; 3, upper ring; 4, fixed block; 5, inner cylinder; 6, support block; 7, filter plate; 8, bottom through hole; 9, side wall through hole; 10, gear ring; 11, end plate; 12, first rotating assembly; 13, drive gear; 14, rotating shaft; 15, clamping block; 16, rotating column; 17, sliding slot; 18, second rotating assembly; 19, guide block; 20, water outlet pipe assembly; 21, water distribution cavity; 22, water supply pipe; 23, blocking ring; 24, first spring; 25, sliding rod; 26, locking clamp; 27, outer pipe; 28, inner pipe; 29, plugging block; 30, water inlet channel; 31, plugging groove; 32, mounting ring; 33, second spring; 35, support leg; 36, fixed rod; 37, feed hopper; 38, blocking block. DETAILED DESCRIPTION

[0016] As Figures 1-7As shown, a kind of impurity removal device for preparing light aggregate from dredged sediment, including outer cylinder 1, the lower end of outer cylinder 1 The inner wall of parallelly arranged lower ring 2 and upper ring 3, the outer side of upper ring 3 and lower ring 2 is fixed to the inner wall of outer cylinder 1, specifically, fixed is connected by fixed block 4, i.e. There is a gap between upper ring 3 and lower ring 2 and the inner wall of outer cylinder 1, to facilitate the subsequent downward flow of diluted dredged sediment, lower ring 2 and upper ring 3 between them are provided with inner cylinder 5, the outer wall of inner cylinder 5 is provided with support block 6, one end of support block 6 is fixed to the outer wall of inner cylinder 5, the other end of support block 6 is located between lower ring 2 and upper ring 3, i.e. Under the action of support block 6, inner cylinder 5 can rotate between upper ring 3 and lower ring 2, the upper end of outer cylinder 1 is provided with end plate 11, the upper end of inner cylinder 5 is rotatably connected to the middle part of end plate 11, bearing can be provided, to further limit inner cylinder 5, while also improving the rotation effect, the outer wall of inner cylinder 5 below end plate 11 is provided with gear ring 10, the inner ring of gear ring 10 is fixed to inner cylinder 5, first rotating assembly 12 (can be motor, such as high precision servo motor) is arranged on end plate 11, drive gear 13 is arranged on the output end of first rotating assembly 12, drive gear 13 and gear ring 10 are engagedly connected, a plurality of circumferentially distributed side wall through holes 9 are arranged on the outer wall of inner cylinder 5 above upper ring 3, filter plate 7 is arranged on the lower inner wall of inner cylinder 5, a plurality of bottom through holes 8 are arranged on filter plate 7, a fixing ring is arranged on the lower end of outer cylinder 1, the inner ring of fixing ring is fixed to outer cylinder 1, a plurality of support legs 35 are arranged on fixing ring, one end of support leg 35 is fixed to fixing ring, feed hopper 37 is arranged above inner cylinder 5, fixed rod 36 is arranged on the outer wall of feed hopper 37, fixed rod 36 connects feed hopper 37 to end plate 11, dilution assembly is arranged in the interior of feed hopper 37, dilution assembly is used to supply water to inner cylinder 5, dilution assembly can be used in cooperation with water pump and water pipe, water in river channel is pumped into feed hopper 37.

[0017] The working principle of the technical solution is: The dredged sludge is transported into the feeding hopper 37 by the excavator or other conveying components (conveying belt), and the dredged sludge conveyed into the feeding hopper 37 should be removed of obvious larger impurities (such as large-diameter branches), and then diluted by the dilution component to pump water into the feeding hopper 37, dilute the dredged sludge with poor fluidity, enhance the fluidity, and clean the dredged sludge adhered to the impurities, and then the first rotating component 12 is started to rotate the driving gear 13 to drive the gear ring 10 to rotate, and then the inner cylinder 5 rotates, and in the process of rotation of the inner cylinder 5, part of the dredged sludge after dilution is thrown outward from the side wall through hole 9 provided on the inner cylinder 5 to the inner wall of the outer cylinder 1 under the action of centrifugal force, and then is intercepted and collected to fall downward, and part of the dredged sludge after dilution is discharged outward from the bottom through hole 8 provided on the filter plate 7 to be collected and collected at the lower end of the outer cylinder 1, and then the dredged sludge and most of the impurities are separated and filtered out from the side wall and the bottom, the efficiency is improved, and because the impurities in the dredged sludge, such as leaves, stones or branches with relatively large diameter, are left in the inner cylinder 5, when there are many impurities left in the inner cylinder 5, the dredged sludge impurity removal operation can be continued after cleaning.

[0018] In an implementable mode, the outer surface of the filter plate 7 is symmetrically provided with a rotating shaft 14, one end of the rotating shaft 14 is fixed to the inner plate, the other end of the rotating shaft 14 is rotatably connected to the side wall of the inner cylinder 5 and passes through the side wall of the inner cylinder 5, the end of the rotating shaft 14 located outside the inner cylinder 5 is provided with a clamping block 15, the clamping block 15 is located between the upper ring 3 and the lower ring 2, the upper ring 3 and the lower ring 2 are symmetrically provided with mounting notches, the mounting notches are both provided with a rotating column 16, the rotating column 16 is in contact with the mounting notches and can rotate in the mounting notches, the middle part of the rotating column 16 is provided with a sliding groove 17, the sliding groove 17 is in communication with the spacing between the upper ring 3 and the lower ring 2, both ends of the rotating column 16 are provided with connecting shafts, the outer side end of one connecting shaft is provided with a stop block 38, and the outer side end of the other connecting shaft is provided with a second rotating component 18 (which can also be a servo motor), and the second rotating component 18 is fixed to the outer wall of the outer cylinder 1.

[0019] The working principle of the above technical scheme is as follows: The inner part of the rotating column 16 is provided with a sliding groove 17, which is communicated with the space between the upper ring 3 and the lower ring 2, so as to avoid the blocking interference caused by the rotation of the supporting block 6. At the same time, the clamping block 15 is limited by the upper ring 3, the lower ring 2 and the sliding groove 17, so that it cannot be deflected by itself, thereby avoiding the problem of deflection of the filter plate 7 inside the inner cylinder 5. When the filter plate 7 needs to be deflected to discharge the impurities inside, at this time, only the first rotating assembly 12 is controlled to rotate the inner cylinder 5, so that the clamping block 15 is located inside the sliding groove 17, and then the second rotating assembly 18 is controlled to rotate, so as to drive the rotating column 16 to rotate, that is, the rotating column 16 drives the clamping block 15 to rotate, and then drives the filter plate 7 to rotate, that is, a gap is formed between the rotating filter plate 7 and the inner wall of the inner cylinder 5, and then the impurities inside the inner cylinder 5 can be discharged downward through the gap (the rotation and sealing of the filter plate 7 can refer to the design of the butterfly valve in the prior art, and will not be described in detail here), when the impurities are discharged, the lower surface of the filter plate 7 is turned over to the upper side for use (turning over for use), which has the advantages that the filter plate 7 can rotate to discharge the impurities left in the inner cylinder 5, and the turning over for use can wash away the part of the impurities adhered to the bottom through hole 8 by the mixture of mud and water in the inner cylinder 5, so as to realize cleaning. Of course, if there are stones and other impurities clamped in the bottom through hole 8, they can be cleaned by manual use of a rod.

[0020] In an implementable manner, a plurality of water supply pipes 22 are circumferentially arranged on the side wall of the outer cylinder 1. As shown in the specific embodiment, the number of the water supply pipes 22 is four. The water supply pipes 22 are connected to the outer cylinder 1. The water supply pipes 22 are provided with water distribution cavities 21 at one end between the inner cylinder 5 and the outer cylinder 1. One side of the water distribution cavity 21 is communicated with the water supply pipe 22. The other side of the water distribution cavity 21 is provided with water outlet pipe assemblies 20 corresponding to the number and position of the side wall through holes 9. The water outlet ends of the plurality of water outlet pipe assemblies 20 are arranged one by one corresponding to the plurality of side wall through holes 9.

[0021] The working principle of the above technical solution is as follows: When the side wall through holes 9 on the inner cylinder 5 need to be cleaned, at this time, only the water pump and the like are connected to the end of the water supply pipe 22, and then high-pressure water is supplied into the water supply pipe 22, that is, the high-pressure water flow passes through the water distribution cavity 21 and is discharged to the side wall through holes 9 from each water outlet pipe assembly 20, that is, the high-pressure water flow is sprayed into the holes of the water outlet pipe assemblies, so as to wash the impurities in the side wall through holes 9 into the inner cylinder 5, and then discharge downward. It is not difficult to understand that at this time, the first rotating assembly 12 drives the inner cylinder 5 to rotate slowly, so that the plurality of side wall through holes 9 on the surface of the inner cylinder 5 can be affected by the high-pressure water flow, thereby improving the cleaning effect.

[0022] In an implementable mode, the water supply pipe 22 is slidingly connected to the outer cylinder 1, the water supply pipe 22 is provided with a blocking ring 23 on one end outside the outer cylinder 1, a first spring 24 is arranged between the blocking ring 23 and the outer cylinder 1, the first spring 24 is sleeved on the water supply pipe 22, and symmetrical slide rods 25 are arranged on the outer wall of the water distribution cavity 21. The symmetrical slide rods 25 can limit the deflection of the water supply pipe 22, so that the plurality of water outlet pipe assemblies 20 are aligned with the positions of the side wall through holes 9. One end of the slide rod 25 is fixed to the water distribution cavity 21, the other end of the slide rod 25 is slidingly arranged through the outer cylinder 1, and a detachable limiting clamp is arranged on one end of the slide rod 25 outside the outer cylinder 1. The locking clamp 26 can adjust the spacing between the end portions of the water outlet pipe assemblies 20 and the side wall through holes 9, so as to avoid rotating interference with the guide blocks 19 during normal work. The inner cylinder 5 is provided with a plurality of circumferentially distributed guide blocks 19. The cross section of the guide block 19 is a right trapezoid, and the wide side of each guide block 19 is fixed to the surface of the inner cylinder 5 between the adjacent two rows of side wall through holes 9.

[0023] The working principle of the above technical scheme is as follows: Adjust the position of the locking clamp 26 outward (as far as possible, do not block the movement of the subsequent slide rod 25), under the action of the first spring 24 (initially under tension, after adjusting the position of the locking clamp 26, lose external force, return to the initial equilibrium state), drive the water supply pipe 22 to move inward, so that the end portion of the water outlet pipe assembly 20 is located between the adjacent guide blocks 19 (the specific position can be adjusted and set according to the actual situation), that is, when cleaning, the rotating inner cylinder 5 drives the guide block 19 to rotate, that is, the inclined surface of the guide block 19 contacts the end portion of the water supply pipe 22 assembly (the end portion is arranged in an arc shape), thereby pushing the plurality of water outlet pipe assemblies 20 to move outward, thereby driving the water supply pipe 22 to move outward, thereby making the first spring 24 under tension. When the end portion of the water outlet pipe assembly 20 moves to the highest position of the guide block 19, the water outlet pipe assembly 20 will be separated from the guide block 19 for an instant, and then under the action of the first spring 24, the water supply pipe 22 and the end portion of the water outlet pipe assembly 20 will move inward, thereby making the end portion of the water outlet pipe assembly 20 move rapidly into the side wall through hole 9, thereby hammering the impurities such as stones clamped in the side wall through hole 9 inward, thereby achieving the technical effect of cleaning the impurities clamped in the side wall through hole 9. Of course, after the first spring 24 loses the elastic force, the end portion of the water outlet pipe assembly 20 also returns to the initial position.

[0024] In an implementable mode, the water outlet pipe assembly 20 arranged on the water distribution cavity 21 comprises an outer pipe 27, one end of the outer pipe 27 is communicated and arranged on the water distribution cavity 21, an inner part of the outer pipe 27 is provided with a blocking block 29, a middle part of the blocking block 29 is provided with a blocking groove 31, one end of the blocking groove 31 away from the water distribution cavity 21 is arranged through the blocking block 29, an inner part of one end of the blocking block 29 towards the water distribution cavity 21 is provided with a plurality of water inlet channels 30, the water inlet channels 30 are communicated with the middle part of the blocking groove 31, the blocking groove 31 is provided with an inner pipe 28, one end of the inner pipe 28 is slidingly connected in the blocking groove 31, the other end of the inner pipe 28 is slidingly connected with the other end of the outer pipe 27, the inner pipe 28 is fixedly provided with a mounting ring 32, the second spring 33 is arranged on the inner pipe 28.

[0025] The working principle of the above technical solution is as follows: When the end of the water outlet pipe assembly 20 contacts the inclined surface on the guide block 19, at this time, the inner pipe 28 moves into the blocking groove 31 against the force of the second spring 33, when the end of the inner pipe 28 moves beyond the water inlet channel 30, the end of the inner pipe 28 is blocked, that is, at this time, the inner pipe 28 will not outlet water, at this time, the water pressure is accumulated in the outer pipe 27, when the end of the inner pipe 28 is separated from the guide block 19, under the action of the second spring 33, the inner pipe 28 moves outward, that is, the end of the inner pipe 28 is reset, at this time, the end of the inner pipe 28 is communicated with the water inlet channel 30, because the end of the inner pipe 28 is blocked, the water pressure is accumulated, the pressure will increase, therefore, at this time, under the action of the water pressure, the inner pipe 28 will compress the second spring 33, so that the inner pipe 28 moves outward, that is, the first spring 24 drives the inner pipe 28 to move a certain distance, the water pressure drives the inner pipe 28 to move a certain distance, that is, at this time, the inner pipe 28 moves a greater distance in the side wall through hole 9, can act on the deep part of the side wall through hole 9, or the inner wall of the inner cylinder 5 (preferably, the water flow of the end of the inner pipe 28 includes water flow directed to the side wall through hole 9, and also includes water flow outwardly sprayed in a diverging circular manner, that is, at this time, the water flow outwardly sprayed by the inner pipe 28 can act on the inner wall surface of the inner cylinder 5 which is not provided with the side wall through hole 9, such as can flush away the adhered leaves and the like), better dredging effect is achieved, at the same time, when the water pressure in the outer pipe 27 is normal, the inner pipe 28 is also reset under the action of the second spring 33.

[0026] In an implementable mode, the plurality of supporting legs 35 are provided with an inclined arranged material receiving plate, the material receiving plate guides the mixture of the bottom mud and water discharged from the upper part into the sedimentation tank, the material receiving plate is detachably connected to the supporting leg 35. The sedimentation tank can be realized by excavation, the diluted dredged bottom mud is deposited through the sedimentation tank, then the upper layer water is pumped out, the dredged bottom mud after impurity removal is obtained, of course, when the impurities in the inner cylinder 5 are cleaned, the material receiving plate can be detached, or can not be detached, only needs to be dropped into the material receiving plate, then manual cleaning is needed, which will not be described in detail here.

[0027] A preparation method of dredged silt for preparing lightweight aggregate, specifically comprising the following preparation steps: S1, impurity removal of silt: removing impurities in the dredged silt through an impurity removal device; S2, water reduction and drying: separating the mixture in the sediment after impurity removal to obtain the dredged silt after impurity removal, and transferring the dredged silt to a drying field for dehydration and drying, with the final water content controlled to be not higher than 12%, to obtain dried silt blocks; S3, crushing and sieving: crushing the dried silt blocks by using a high-speed crusher, and sieving through a 0.25 mm standard sieve to obtain uniform fine silt powder, which is sealed and moisture-proof for storage; S4, base material compounding: taking 50-65 parts of dried silt powder, 20-30 parts of auxiliary cementing material (such as a compound of fly ash and slag), 5-8 parts of alkaline activator (quicklime or carbide slag), 3-5 parts of microsilica powder, 0.3-1.2 parts of foaming component (such as aluminum powder or hydrogen peroxide), and 0.1-0.4 parts of structure stabilizer (such as carboxymethyl cellulose or stearate), adding an appropriate amount of water to make the system into a flowable slurry, and stirring uniformly; S5, granulation and foaming: injecting the mixed slurry into a disc granulator or an extrusion granulation device, and synchronously introducing trace gas for foaming to form wet granular green bodies with a particle size of 5-15 mm; S6, static curing: placing the wet granules in a curing room with a relative humidity of ≥75% and a temperature of 35-50℃ for 12-18 hours to promote preliminary curing and strength development; S7, thermal activation treatment: transferring the pre-cured granules into a rotary kiln or a box furnace, heating at a rate of 3-8℃ / min to 900-1000℃, maintaining the temperature for 20-40 minutes, and then naturally cooling to obtain lightweight aggregate products with porous interiors and vitrified surfaces.

[0028] It should be noted that the above steps are basic steps for preparing lightweight aggregate from dredged silt, and are only used to prove that dredged silt can be used to prepare lightweight aggregate. The specific values of the bulk density and cylinder compressive strength of the prepared lightweight aggregate are not described in detail here, because lightweight aggregate with different parameters can be used in different places of construction (for example, lightweight aggregate with excellent values can be used for building concrete, and lightweight aggregate with relatively poor values can be used for preparing decorative products such as sidewalks or artificial hills). Of course, in order to make the present scheme more perfect, a specific embodiment of the present preparation scheme is given as follows: The dredged sludge is removed by the impurity removal device, then is plate frame pressure filtered to 35% moisture content, and is dried for 7-10.5 days, then is hammer broken and is passed through a 0.25 mm sieve to obtain fine sludge powder; 60 parts of the dried sludge powder is mixed with 20 parts of fly ash, 6 parts of quicklime, 4 parts of microsilica powder, 0.8 parts of aluminum powder and 0.3 parts of carboxymethyl cellulose, and then 25 parts of water is added to prepare a slurry, and 10 mm green balls are prepared by a disc granulator at 35 rpm, and then the green balls are pre-cultured at 40 DEG C and 80% RH for 16 hours; the green balls are put into a rotary kiln, and the temperature is raised to 980 DEG C at a rate of 5 DEG C / min and is kept for 30 min, and then is naturally cooled to obtain porous lightweight aggregate with a bulk density of 820 kg / m3 and a cylinder compressive strength of 3.4 MPa (the cylinder compressive strength here is the "minimum sintering" strength, at this time the surface of the particles is only initially vitrified, and the internal porosity is 45-55%, which is used to prove that the preparation method is feasible; when it is needed to be used, low-melting fluxing agent (Na2O·SiO2, borax) is added or the temperature is raised, so that the cylinder compressive strength can be raised to more than 6 MPa, which meets the requirements of the national standard lightweight aggregate, and here is not described in more detail).

[0029] Finally, it should be pointed out that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present application.

Claims

1. A device for removing impurities from dredged sediment used in the preparation of lightweight aggregates, characterized in that: The device includes an outer cylinder, on the lower inner wall of which a lower ring and an upper ring are arranged parallel to each other. An inner cylinder is located between the lower and upper rings. A support block is circumferentially arranged on the outer wall of the inner cylinder, located between the lower and upper rings. An end plate is provided at the upper end of the outer cylinder. The upper end of the inner cylinder is rotatably connected to the middle of the end plate. A gear ring is provided on the outer wall of the inner cylinder below the end plate. The inner ring of the gear ring is fixed to the inner cylinder. A first rotating assembly is provided on the end plate. A drive gear is provided on the output end of the first rotating assembly. The drive gear and the gear ring are meshed together. The outer wall of the inner cylinder above the upper ring has several circumferentially distributed side wall through holes. The lower inner wall of the inner cylinder has a filter plate with several bottom through holes. The lower outer wall of the outer cylinder has a fixing ring with its inner ring fixed to the outer cylinder. The fixing ring has several support legs with one end fixed to the fixing ring. The upper part of the inner cylinder has a feed hopper with a fixing rod on its outer wall. The fixing rod connects the feed hopper to the end plate. The inside of the feed hopper has a dilution component for supplying water to the inner cylinder.

2. The impurity removal device for dredged sediment used in the preparation of lightweight aggregates according to claim 1, characterized in that: The outer surface of the filter plate is symmetrically provided with rotating shafts. One end of the rotating shaft is fixed to the inner plate, and the other end of the rotating shaft is rotatably connected to the side wall of the inner cylinder and passes through the side wall of the inner cylinder. A locking block is provided on the end of the rotating shaft outside the inner cylinder. The locking block is located between the upper ring and the lower ring. The upper ring and the lower ring are symmetrically provided with mounting notches. A rotating column is provided in each mounting notch. The rotating column is in contact with the mounting notch and can rotate within the mounting notch. A sliding groove is provided in the middle of the rotating column. The sliding groove is connected to the distance between the upper ring and the lower ring. Both ends of the rotating column are provided with connecting shafts. A stop is provided on the outer end of one connecting shaft, and a second rotating assembly is provided on the outer end of the other connecting shaft. The second rotating assembly is fixed to the outer wall of the outer cylinder.

3. The impurity removal device for dredged sediment used in the preparation of lightweight aggregates according to claim 1, characterized in that: The outer cylinder has several water supply pipes circumferentially arranged on its side wall. The water supply pipes are connected to the outer cylinder. A water distribution cavity is provided at one end of the water supply pipe located between the inner cylinder and the outer cylinder. One side of the water distribution cavity is connected to the water supply pipe. The other side of the water distribution cavity is provided with water outlet pipe assemblies that correspond to the number and position of a row of side wall through holes. The water outlet ends of several water outlet pipe assemblies are arranged one-to-one with a row of side wall through holes.

4. The impurity removal device for dredged sediment used in the preparation of lightweight aggregates according to claim 3, characterized in that: The water supply pipe is slidably connected to the outer cylinder. A retaining ring is provided on one end of the water supply pipe outside the outer cylinder. A first spring is provided between the retaining ring and the outer cylinder. The first spring is sleeved on the water supply pipe. Sliding rods are symmetrically provided on the outer wall of the water distribution cavity. One end of the sliding rod is fixed to the water distribution cavity, and the other end of the sliding rod slides through the outer cylinder. A detachable limiting clamp is provided on one end of the sliding rod outside the outer cylinder. Several circumferentially distributed guide blocks are provided on the inner cylinder. The cross-section of the guide blocks is a right trapezoid. The side with the larger width of the guide blocks is fixed to the inner cylinder surface between two adjacent rows of side wall through holes.

5. The impurity removal device for dredged sediment used in the preparation of lightweight aggregates according to claim 4, characterized in that: The water distribution chamber is provided with several water outlet pipe assemblies, including an outer pipe. One end of the outer pipe is connected to the water distribution chamber. A sealing block is provided inside the outer pipe. A sealing groove is provided in the middle of the sealing block. The end of the sealing groove away from the water distribution chamber passes through the sealing block. Several water inlet channels are provided inside the end of the sealing block facing the water distribution chamber. The water inlet channels are connected to the middle of the sealing groove. An inner pipe is provided in the sealing groove. One end of the inner pipe is slidably connected to the sealing groove. The other end of the inner pipe is slidably connected to the other end of the outer pipe. An installation ring is provided on the inner pipe. A second spring is provided between the installation ring and the other end of the outer pipe. The second spring is sleeved on the inner pipe.

6. The impurity removal device for dredged sediment used in the preparation of lightweight aggregates according to claim 1, characterized in that: An inclined receiving plate is provided between several of the support legs. The receiving plate guides the mixture of bottom mud and water discharged from the top into the sedimentation tank. The receiving plate is detachably connected to the support leg.

7. A method for preparing lightweight aggregate from dredged sediment, characterized in that: The preparation steps include the following: S1. Sediment removal: removing impurities from the dredged sediment using any of the impurity removal devices described in claims 1-6; S2. Water Reduction and Drying: The mixture in the sediment after impurity removal is separated into mud and water to obtain the dredged bottom mud after impurity removal. It is then transferred to the drying yard for dehydration and drying, and the final moisture content is controlled to be no more than 12% to obtain dried mud blocks. S3. Crushing and sieving: Use a high-speed crusher to crush the dried mud blocks to obtain uniform fine mud powder, which is then sealed and stored in a moisture-proof container for later use. S4. Substrate compounding: Take dried mud powder, auxiliary binder, alkaline activator, microsilica powder, foaming component and structural stabilizer, add an appropriate amount of water to make the system a flowable slurry, and stir evenly; S5. Granulation and foaming: The mixed slurry is injected into a disc granulator or extrusion granulator, and a small amount of gas is introduced simultaneously to foam, forming a wet granular preform with a particle size of 5-15mm. S6. Static curing: Place the wet granules in a curing room and let them stand to promote initial curing and strength development; S7. Thermal activation treatment: The pre-cured particles are transferred into a rotary kiln or box furnace, heated at a constant temperature and then cooled naturally to obtain a lightweight aggregate product with internal porosity and surface vitrification.

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