Staggered scraper type extractor and extraction method thereof

Abstract

A staggered scraper type extractor and an extraction method thereof. A chamber (3) is provided with a plurality of longitudinal partition plates (3a) parallel to each other, and the longitudinal partition plates (3a) divide the chamber (3) in the width direction into a plurality of soaking tanks (3k) which are arranged side by side and are sequentially connected in series; each soaking tank (3k) is provided with an inclined bottom wall (3b), and the inclination directions of inclined bottom walls (3b) of adjacent soaking tanks (3k) are opposite; and an annular chain scraping mechanism is provided in each soaking tank (3k), and a temporary storage and feeding device is mounted above a first-stage soaking tank (3k). A chain partition plate (3c) is provided above each inclined bottom wall (3b), each chain partition plate (3c) is parallel to the corresponding inclined bottom wall (3b) below, the upper layer of the chain scraping mechanism moves downwards along the corresponding chain partition plate (3c), and the lower layer of the chain scraping mechanism is used for fishing out materials from the tank bottom of the corresponding soaking tank (3k) and draining, and pushing the materials upwards along the inclined bottom wall (3b). A fresh solvent enters the space below from a slit type opening (3c1) of a last-stage chain partition plate (3c), and after turning from the bottom, the fresh solvent moves upwards by a distance along the chain partition plate (3c) and then overflows to the prior stage; and the advancing direction of the materials is opposite to that of the solvent, achieving full-counterflow soaking type extraction.

Description

Staggered scraper extractor and extraction method thereof Technical Field

[0001] The invention relates to an extraction device, in particular to a staggered scraper type extractor. The invention also relates to an extraction method of the staggered scraper type extractor, belonging to the technical field of solvent extraction. Background Art

[0002] Oil-containing waste clay is a waste product generated during the oil refining process. Taking palm oil refining as an example, during the oil bleaching process, 1.0-2.0 kg of activated clay is typically added per ton of vegetable oil to adsorb pigment particles, colloids, soap particles, and other impurities. After the bleaching process, the clay is filtered through a leaf filter to form a filter cake. This oil-containing filter cake is then purged with compressed air (or saturated steam), yielding waste clay containing 20-40% oil. Improper storage and handling of the waste clay can lead to spontaneous combustion. Exposure to the atmosphere can rapidly cause rancidity, resulting in a pungent odor, the release of contaminated oil, and other adverse effects, leading to high storage and disposal costs. Direct landfilling can contaminate the landfill area and create secondary hazards such as groundwater contamination. With increasing environmental awareness and the need for sustainable development, the harmless treatment of waste clay is becoming increasingly necessary for large-scale oil refining companies.

[0003] The most effective method for treating waste clay is extraction. The extracted acid oil can be used industrially or processed into biodiesel. The main components of clay are aluminum oxide and silicon oxide. After desolventizing and recovering the solvent, it can be used as a building brick material.

[0004] Spent clay exhibits unstable properties under varying moisture content and pressure, sometimes solid and sometimes nearly paste-like. A wide variety of extraction equipment is available on the market. The general principle is to allow the solids to naturally accumulate into a stable bed, or to force a stable bed into place. The extraction or washing liquid is then poured in from above the bed, where it penetrates the bed, completing the mass transfer process. This type of equipment has specific particle size requirements for the solid waste clay. Excessive fineness in the solid waste clay results in insufficient porosity in the bed. When the porosity falls below 5%, the permeation rate decreases or even disappears.

[0005] Chinese invention patent publication number CN 216755454U discloses a flat-bottom immersion scraper extractor. The extractor chamber is equipped with an endless chain, with scrapers mounted at even intervals on the chain. The scrapers extend transversely along the chamber, and the chamber has a horizontal bottom wall. A drive shaft is mounted on the upper portion of the chamber's head end, with a drive sprocket mounted on the drive shaft; a head-end driven shaft is mounted on the head-end driven sprocket; and a tail-end driven shaft is mounted on the tail-end driven sprocket. The endless chain is sequentially wrapped around the drive sprocket, the head-end driven sprocket, and the tail-end driven sprocket, forming a triangle with a vertical section, a horizontal section, and an inclined section. The extractant is stored in an immersion pool at the bottom of the chamber, with the horizontal section entirely submerged in the pool. This extractor structure has limited production capacity and has not yet been applied to large or ultra-large extraction production lines.

[0006] The Chinese invention patent with publication number CN 216755456U discloses a parallel scraper extractor, in which an annular chain is provided in the inner cavity of the box, and scrapers are evenly installed on the annular chain, and the scrapers extend horizontally along the box. The box is provided with an inclined bottom wall with a higher head end and a lower tail end. A drive shaft is provided at the upper part of the head end of the box, and a drive sprocket is installed on the drive shaft; a tensioning shaft is provided at the upper part of the tail end of the box, and a tensioning sprocket is installed on the tensioning shaft; a driven shaft is provided at the lower part of the tail end of the box, and a driven sprocket is installed on the driven shaft; the annular chain is sequentially wrapped around the drive sprocket, the tensioning sprocket and the driven sprocket to form a triangle including a horizontal section, a vertical section and an inclined section, and the inclined section is parallel to the inclined bottom wall of the box. The extraction liquid is stored at the bottom of the box to form an immersion pool, and the lower part of the inclined section is immersed in the immersion pool. The extractor adopts a V-shaped groove, which is suitable for extracting powdered fiber materials. The extraction efficiency is extremely high for powdered materials; however, the production capacity achieved by this structural type is not high and it is not suitable for large and ultra-large leaching production lines.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the problems existing in the prior art and provide a staggered scraper extractor with a reasonable flow channel arrangement, which can realize full countercurrent immersion extraction, maintain a large extraction power throughout the process, operate stably and reliably, and is suitable for large-scale extraction of oil-containing waste white clay.

[0009] In order to solve the above technical problems, the present invention provides an interlaced scraper extractor, comprising a box body, wherein the box body is provided with a plurality of longitudinal partitions extending along the length direction of the box body and parallel to each other, and each longitudinal partition divides the box body into a plurality of soaking pools arranged side by side and connected in series in sequence; each soaking pool is provided with an inclined bottom wall, and the inclined directions of the inclined bottom walls of adjacent soaking pools are opposite, and each soaking pool is provided with an annular chain scraping mechanism, and a temporary storage feeding device is installed above the first-stage soaking pool.

[0010] Furthermore, a chain partition is provided above each inclined bottom wall, and each chain partition is parallel to the inclined bottom wall below. The upper layer of the chain scraper mechanism descends along the corresponding chain partition, and the lower layer of the chain scraper mechanism scoops the material from the bottom of the corresponding immersion pool, drains it, and pushes it upward along the inclined bottom wall.

[0011] Furthermore, the upper end of each inclined bottom wall is provided with a transverse chute for guiding the material to the lower end of the next level of soaking pool.

[0012] Furthermore, each inclined bottom wall is provided with a transverse main inclined chute near the upper end to guide the material to the lower end of the next immersion pool; the uppermost end of each inclined bottom wall is provided with a transverse auxiliary inclined chute to guide the material to the lowest point of the next immersion pool.

[0013] Furthermore, the angle between the bottom wall of the transverse main inclined chute and the transverse auxiliary inclined chute and the horizontal plane is greater than 60°, and the angle between the inclined bottom wall and the horizontal plane is less than 15°.

[0014] Furthermore, the middle sections of adjacent longitudinal partitions are provided with interstage overflow ports for overflowing to the upper level immersion tank, and the interstage overflow ports are respectively located above the chain partition of the current level and below the chain partition of the upper level.

[0015] Furthermore, the interstage overflow ports of two connected stages are staggered with each other in the length direction of the soaking tank.

[0016] Furthermore, a fresh solvent supply inlet is provided above the upper part of the chain partition in the final immersion tank, and a slit is provided above the liquid level of the final chain partition for solvent to pass through; a concentrated solvent outflow outlet is provided on the box wall on the lowest end side of the first immersion tank.

[0017] Furthermore, the fresh solvent first falls on the upper part of the chain partition of the final soaking tank, and in the process of flowing downward and rightward, it covers the full width of the chain partition, and then falls from the slit like a waterfall, enters the soaking space between the final chain partition and the inclined bottom wall, and flows downward and rightward, washing the powder moving in the opposite direction and performing the final extraction. After reaching the bottom of the final soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and leftward.

[0018] The extracting liquid enters the bottom of the chain partition of the upper soaking tank from the interstage overflow port of the last stage, enters the soaking space between the chain partition of this stage and the inclined bottom wall, and flows downward and leftward to extract the powder moving in the opposite direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the top of the chain partition, and then flows upward and rightward; the extracting liquid enters the bottom of the chain partition of the upper soaking tank from the interstage overflow port of this stage, enters the soaking space between the chain partition of this stage and the inclined bottom wall, and flows downward and rightward to extract the powder moving in the opposite direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the top of the chain partition, and then flows upward and leftward; then it enters the upper stage from the interstage overflow port, and so on.

[0019] Furthermore, a first-stage draining tank is provided outside the final soaking tank. The longitudinal partition between the draining tank and the final soaking tank is a closed structure below the liquid level. A chute is provided at the upper end of the inclined bottom wall of the draining tank and is connected to the material outlet.

[0020] Furthermore, the chain scraper mechanism includes a scraper chain and a scraper evenly fixed on the scraper chain. The upper end of each group of scraper chains is wrapped around the head wheel and is located above the liquid surface. The lower end of each group of scraper chains is wrapped around the tail wheel and immersed in the extraction liquid. The head wheels located at the same end of the extractor are commonly fixed on the corresponding driving long shafts. The shaft ends of the two driving long shafts are respectively installed with main driving wheels, and the two main driving wheels are respectively driven by their respective scraper driving mechanisms.

[0021] Furthermore, each tail wheel is fixed to the middle of its own driven short shaft, and both ends of each driven short shaft are supported on the bottom of the longitudinal partition of the adjacent soaking tank through bearings.

[0022] Furthermore, the shaft end of the driven short shaft is supported in a sliding bearing, the sliding bearing is embedded in the driven bearing seat, the outer port of the driven bearing seat is covered with a sealing blind cover, the driven bearing seat is sealed and fixed at the center hole of the driven shaft end plate, and the driven shaft end plate is sealed and fixed on the corresponding longitudinal partition.

[0023] Furthermore, the temporary storage feeding device includes a temporary storage bucket, which is tapered in length and width, narrow at the top and wide at the bottom. A feeding valve is installed at the lower port of the temporary storage bucket, and the feeding valve includes:

[0024] The impeller shafts are provided with two parallel shafts, and extend along the length direction of the feeding valve respectively;

[0025] Feed blades are radially distributed on the outer periphery of the impeller shaft, located in the inner cavity of the valve body and extending along the length direction of the impeller shaft. The outer edge of each feed blade points to the outer wall of the adjacent impeller shaft. The feed blades on adjacent impeller shafts are cross-engaged and the phase difference is half of the angle between two coaxial adjacent feed blades.

[0026] The valve body, the upper and lower ports are both rectangular, and the length direction is provided with an arc-shaped side wall to match the rotation circle of the feeding blade;

[0027] Synchronous gears are respectively mounted on the same side shaft ends of the two impeller shafts and mesh with each other to make the two impeller shafts rotate synchronously in opposite directions;

[0028] The driving wheel is installed on the other side of one of the impeller shafts.

[0029] The feeding speed reduction mechanism has an input end driven by a feeding motor and an output end driving the driving wheel through a chain or a synchronous belt.

[0030] Another object of the present invention is to overcome the problems existing in the prior art and provide an extraction method of a staggered scraper extractor, in which the flow channel is reasonably arranged, full countercurrent immersion extraction can be achieved, a large extraction power is maintained throughout the entire process, the operation is stable and reliable, and it is suitable for large-scale extraction of oil-containing waste white clay.

[0031] In order to solve the above technical problems, the extraction method of the staggered scraper extractor of the present invention adopts the staggered scraper extractor as claimed in claim 8, and comprises the following steps in sequence:

[0032] A1. Fresh solvent first falls on the upper part of the chain partition of the final soaking tank, flows downward and rightward, and covers the entire width of the chain partition. It then falls through the slit like a waterfall and enters the soaking space between the final chain partition and the inclined bottom wall. It flows downward and rightward, washing the powder moving in the opposite direction and performing the final extraction. After reaching the bottom of the final soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then turns upward and flows leftward.

[0033] A2. The extract flows from the interstage overflow port of the final stage into the bottom of the chain partition of the previous soaking tank, then into the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and leftward to extract the powder moving in the opposite direction. After reaching the bottom of this soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then flows upward and rightward.

[0034] A3. The extract flows from the interstage overflow port of this stage into the lower part of the chain partition of the upper soaking tank, then into the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and rightward to extract the powder moving in the opposite direction. After reaching the bottom of the soaking tank of this stage, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then flows upward and leftward.

[0035] A4. The extract then enters the immersion space between the chain partition and the inclined bottom wall of the previous stage from the interstage overflow port, and so on;

[0036] A5. After the extract reaches the bottom of the first-stage immersion tank, it bypasses the lower edge of the chain partition and flows upward from the concentrated solvent outlet.

[0037] Furthermore, the temporary feeding device feeds new materials into the first-stage immersion tank and they fall onto the chain partition. They are pushed downward and rightward by the scraper and immersed under the liquid surface. After reaching the bottom of the first-stage immersion tank, they turn and enter the immersion space between the chain partition and the inclined bottom wall, move upward and leftward, and are extracted. After gradually drying out of the liquid surface, they continue to move upward and leftward and drain.

[0038] The material drained in the first stage slides horizontally from the upper part of the inclined bottom wall of the first stage into the lower end of the second stage soaking tank, moves upward and rightward along the soaking space between the chain partition and the inclined bottom wall of this stage and is extracted. After gradually drying out of the liquid surface, it continues to move upward and rightward and drain, and slides horizontally from the upper part of the inclined bottom wall into the lower end of the third stage soaking tank, and so on.

[0039] The material on the upper end of the inclined bottom wall of the final soaking tank falls into the lower end of the draining tank, climbs along the inclined bottom wall of the draining tank and is finally drained, and then discharged to the material outlet through the discharge chute.

[0040] Compared with the existing technology, the present invention has achieved the following beneficial effects: 1. The temporary storage feeding device solves the demand for temporary storage of materials before immersion, providing a guarantee for continuous and stable feeding; the double impeller structure increases the inlet width, effectively improves the passability of the upper inverted cone-shaped temporary storage bucket, and eliminates arching and bridging; after the lower end of the temporary storage bucket is widened, its effective volume is significantly increased, and the buffer space becomes larger, which can meet the needs of continuous and stable feeding.

[0041] 2. The relative position of the two impellers is determined by synchronous gears. A fixed phase difference is maintained between the two impellers, resulting in counter-rotation similar to meshing. The blades on the two impeller shafts have the function of mutual self-cleaning to prevent the roots of the blades from being stuck to the material. The use of volumetric impellers can accurately control the feed amount to prevent machine blockage caused by excessive feed. The impellers are open at both ends to avoid the formation of gaps between the impellers and the valve body. The impellers do little work on the material, consume less power, and have low operating costs.

[0042] 3. The temporary feeding device has a compact structure and good functionality. The feeding valve is a modular structure, plug and play, convenient and fast; it is suitable for batch production and reduces manufacturing costs by 30% compared to spiral feeding devices.

[0043] 4. The material is immersed in the solvent to achieve immersion, and extraction is carried out by utilizing the mutual solubility of the solute and solvent. Multiple sets of X-shaped immersion tanks effectively compress the length dimension, allowing the main body of the equipment to be appropriately expanded in the width direction, greatly shortening the equipment length. The scraper chains are arranged in a positive and negative pattern across the width of the extractor, which appropriately expands the main body of the equipment in the width direction, significantly shortening the overall length of the multi-stage extraction equipment, extending the effective immersion path, reducing the equipment surface area, and saving materials.

[0044] 5. All levels are fully immersion extraction tanks, which are more suitable for extracting powdered materials than leaching extraction tanks. The mass transfer efficiency during the extraction process is greatly improved. The mass transfer efficiency of full immersion extraction is 300-400% higher than that of traditional leaching extraction. Compared with leaching extraction, which takes 90-120 minutes, immersion extraction can achieve or exceed the same mass transfer efficiency in just 30 minutes.

[0045] 6. The scraper chain's head pulley is the active pulley, eliminating sealing issues between adjacent head pulleys. A common drive shaft drives the entire system, ensuring consistent speeds between stages. A drive shaft is located at each end of the extractor, allowing each shaft to bear only half the load of the immersion tank, reducing failure rates. The scraper chain's tail pulley is an idler pulley, mounted on segmented driven short shafts. Each driven short shaft does not pass through the partitions between adjacent immersion tanks, simplifying sealing, improving reliability, and preventing interstage liquid cross-contamination.

[0046] 7. Multiple sets of X-cross scrapers increase the frequency of material turning, achieve good mixing effect, and improve mass transfer efficiency. The structure of the transmission mechanism is mature and simple, with high efficiency in pushing and discharging materials, ensuring smooth flow of materials inside the equipment.

[0047] 8. The inclination angle between the chain push plate and the horizontal plane is controlled below 15°, which is suitable for the extraction of powder materials with a very small static friction angle. It has high reliability, and the flow channel is reasonably set. The countercurrent flow of the material and the solvent realizes full countercurrent immersion extraction, maintains a large extraction power, and has high extraction efficiency. It can solve the problem of large-scale extraction of oil-containing waste white clay.

[0048] 9. The maximum and minimum liquid levels are fixed, and each stage features a draining process that allows for separation from the liquid surface. A separate draining stage is provided before exiting the extractor, achieving the goal of large-scale, efficient extraction. This system is suitable for harsh working conditions, boasts high reliability, a rational process layout, and a robust and reliable solution. It is particularly suitable for micron-sized powders such as clay, which can "metamorphose" under fluctuating fluid Reynolds numbers. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention.

[0050] FIG1 is a front view of a staggered scraper extractor according to the present invention;

[0051] Figure 2 is a left side view of Figure 1;

[0052] FIG3 is a top view of the extraction tank of the present invention;

[0053] FIG4 is a cross-sectional view along AA in FIG3 ;

[0054] FIG5 is a cross-sectional view along line BB in FIG3 ;

[0055] FIG6 is a cross-sectional view taken along CC in FIG3 ;

[0056] FIG7 is a cross-sectional view along DD in FIG3 ;

[0057] FIG8 is a cross-sectional view along line EE in FIG1 ;

[0058] FIG9 is a cross-sectional view along line FF in FIG8 ;

[0059] FIG10 is a perspective view of the transmission mechanism of the present invention;

[0060] Figure 11 is a cross-sectional view of the tail wheel portion of the transmission mechanism;

[0061] FIG12 is a perspective view of a temporary storage feeding device according to the present invention;

[0062] FIG13 is a cross-sectional view of the feeding valve of the present invention;

[0063] FIG14 is a perspective view of the temporary storage feeding device with the valve body and the protective cover removed;

[0064] Figure: 1. Temporary storage hopper; 1a. Feed inlet; 2. Feed valve; 2a. Valve body; 2b. Feed motor; 2c. Feed reduction mechanism; 2d. Feed chain; 2e. Feed drive wheel; 2f. Synchronous gear; 2g. Impeller shaft; 2g1. Core shaft; 2g2. Steel pipe; 2g3. Annular plate; 2h. Feed blades; 2j. Annular rib plate;

[0065] 3. Box; 3a. Longitudinal partition; 3a1. Interstage overflow port; 3b. Inclined bottom wall; 3c. Chain partition; 3c1. Slit port; 3d. Extraction material inlet; 3e. Horizontal main inclined chute; 3f. Horizontal auxiliary inclined chute; 3g. Material outlet; 3h. Fresh solvent inlet; 3j. Concentrated solvent outlet; 3k. Soaking tank; 3m. Drainage tank;

[0066] 4. Driving long shaft; 5. Head wheel; 6. Scraper chain; 7. Scraper; 8. Tail wheel; 9. Driven short shaft; 10. Driven shaft end plate; 11. Sliding bearing; 12. Driven bearing seat; 13. Sealing blind cover; 14. Driving reducer; 15. Main transmission chain; 16. Main driving wheel.

[0067] Implementation Method

[0068] In the following description of the present invention, the terms "upper," "lower," "front," "back," "left," "right," "inner," and "outer," etc., indicating directions or positions, are based on the directions or positions shown in the accompanying drawings. These terms are used solely to facilitate and simplify the description of the present invention and do not necessarily imply that the device must have a specific orientation. The immersion tank into which the material enters first is referred to as the "upper stage," and the immersion tank into which the material enters later is referred to as the "lower stage."

[0069] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention.

[0071] As shown in Figures 1 to 7, the staggered leaching extraction tank of the present invention includes a box body 3, which is provided with a plurality of longitudinal partitions 3a extending along the length direction of the box body and parallel to each other. Each longitudinal partition 3a divides the box body 3 into a plurality of side-by-side immersion pools 3k in the width direction. Each immersion pool 3k is provided with an inclined bottom wall 3b, and the inclined directions of the inclined bottom walls 3b of adjacent immersion pools 3k are opposite.

[0072] A chain partition 3c is located above each inclined bottom wall 3b, parallel to the inclined bottom wall 3b below. A scraper descends along the chain partitions 3c, reaches the bottom of the soaking tank 3k, turns, and pushes the powder upward along the inclined bottom wall 3b. The angle between the inclined bottom wall 3b and the horizontal plane is less than 35°, facilitating the scraper's upward push of the powder along the inclined bottom wall 3b and reducing resistance.

[0073] Once the material falls into the lower end of the immersion tank (3k) and contacts the solvent surface, efficient mass transfer begins. The solid particles are completely surrounded by solvent, minimizing the mass transfer path. Solutes adsorbed on the surface of the solid particles are dissolved and desorbed within seconds by the turbulent solvent flow. Several countercurrent washes maintain a high extraction dynamics. Finally, fresh solvent washes are applied. Due to the extremely high purity of the fresh solvent, any remaining solutes are completely removed.

[0074] Each inclined bottom wall 3b is equipped near its upper end with a transverse main chute 3e, which guides material to the lower end of the next immersion tank. At the top end of each inclined bottom wall 3b, a transverse auxiliary chute 3f is also installed, which guides material to the lowest point of the next immersion tank. The angle between the bottom walls of the main and auxiliary transverse chutes 3e and 3f and the horizontal plane is greater than 60°, facilitating the natural descent of the powder under the influence of gravity. To prevent powder from accumulating in the main and auxiliary transverse chutes 3e and 3f, nozzles are installed above the corresponding chutes to spray a solvent, causing the powder to collapse and slide rapidly.

[0075] The majority of the powdered material falls preemptively from the transverse main inclined chute 3e onto the inclined bottom wall 3b of the next-stage immersion tank, preventing excessive powder from bypassing the tail shaft and causing blockage. A small amount of powdered material adhering to the chain pusher can further fall as the head wheel rotates, dropping from the transverse auxiliary inclined chute 3f into the very tail of the next-stage immersion tank 3k. This eliminates the problems of material backflow and accumulation on the chain pusher, ensuring smooth conveyance of solid materials. Pushed by the scraper, the material bypasses the tail wheel of the next stage and enters the lower end of the inclined bottom wall 3b, where it is extracted while ascending a gentle slope and gradually emerging from the liquid surface.

[0076] A temporary feeding device is located above the extraction material inlet 3d in the middle of the first-stage immersion tank. Powdered material enters through this inlet, first landing on the chain partition 3c and being pushed downward by the scraper. Upon reaching the lowest point of the immersion tank 3k, it curves and is pushed upward along the inclined bottom wall 3b, undergoing counter-extraction with the extraction liquid. To minimize solute carryover when the powdered material enters the next stage, it undergoes a suitable draining process after exiting the liquid before entering the next extraction stage. This ensures a clear concentration gradient between each stage of the extraction liquid, consistently providing strong extraction power for the granular material.

[0077] When the powder reaches the liquid level above the inclined bottom wall 3b, it enters the draining stage. After continuing to flow upward for a while along the draining stage, most of the powder falls into the second-stage soaking tank through the horizontal main inclined chute 3e. A small amount of powder continues to flow upward and falls into the second-stage soaking tank through the horizontal auxiliary inclined chute 3f. After multiple stages of soaking, it reaches the final soaking tank.

[0078] A fresh solvent inlet 3h is provided above the upper portion of the chain partition 3c in the final immersion tank. A slit 3c1 is provided above the liquid level of the final chain partition, allowing the solvent to pass through. Fresh solvent first falls onto the upper portion of the chain partition 3c in the final immersion tank, dissipating energy while ensuring uniform distribution across the width of the chain partition 3c. It then flows downward along the chain partition 3c for a distance, cascading down through the slit 3c1 like a waterfall, into the immersion space between the chain partition 3c and the inclined bottom wall 3b. It then flows downward along the inclined bottom wall 3b, performing reverse washing and final extraction on the upwardly pushed powder. Upon reaching the bottom of the final immersion tank, the solvent bypasses the lower edge of the chain partition 3c, enters the upper portion, and then flows upward.

[0079] An interstage overflow port 3a1 for overflowing to the upper soaking tank is provided in the middle section of the adjacent longitudinal partition 3a. The interstage overflow port 3a1 is respectively located above the chain partition of the current stage and below the chain partition of the previous stage. The height of the interstage overflow port 3a1 is lower than the slit 3c1 of the last chain partition.

[0080] The overflow ports 3a1 between the two connected stages are staggered in the length direction of the soaking tank, separated by the chain partition 3c and with opposite flow directions, which completely avoids short-circuiting between stages and ensures full countercurrent extraction.

[0081] The extract entering the upper-stage immersion tank from the interstage overflow port 3a1 first flows downward along the immersion space between the chain partition 3c and the inclined bottom wall 3b. After reaching the bottom of the immersion tank, it bypasses the lower edge of the chain partition 3c and enters the upper part of the chain partition 3c, then flows upward until it passes through the interstage overflow port 3a1 and enters the next stage.

[0082] After multiple extraction stages, the extract enters the first-stage immersion tank, flows downward along the immersion space between the chain partition 3c and the inclined bottom wall 3b to the tail end of the first-stage immersion tank, where it overflows upward through the concentrated solvent outlet 3j on the wall of the tank at the tail end of the first-stage immersion tank. The solvent flows autonomously due to the liquid level difference, ensuring that the overflow outlet 3a1 between stages maintains a consistent height.

[0083] For materials with high moisture content and impregnation, such as wet meal, a dedicated draining tank 3m is installed outside the final soaking tank. A longitudinal partition 3a between the draining tank 3m and the final soaking tank is a closed structure below the liquid level to isolate the solvent. Powdered material ascends along the inclined bottom wall 3b of the draining tank 3m to the upper portion and is discharged through a discharge chute to the material outlet 3g at the lower end of the tank side wall.

[0084] As shown in Figures 8 to 11, the transmission mechanism includes multiple groups of head wheels 5, scraper chains 6 and tail wheels 8. Each scraper chain 6 is located in its own soaking pool. Each scraper chain 6 is inclined along the bottom wall of the corresponding soaking pool, and the inclination directions of two adjacent groups of scraper chains 6 are opposite. Scrapers 7 are evenly fixed along the entire length of each scraper chain 6 to push the material to climb along the inclined bottom wall of the soaking pool.

[0085] The upper end of each group of scraper chains 6 is wrapped around the head wheel 5, and each head wheel 5 is located at the high end of the soaking tank. Since the soaking tanks are arranged in sequence, one positive and one negative, the two adjacent head wheels 5 at the same end are separated by the width of a soaking tank, and the head wheel 5 of the soaking tank in the middle is located at the other end of the extractor.

[0086] The head pulleys 5 at the same end of the extractor are fixed to the corresponding drive shaft 4. The ends of the two drive shafts 4 are respectively mounted with main drive wheels 16. The scraper drive mechanism includes a drive reducer 14. The input end of the drive reducer 14 is driven by the scraper motor, and the output end of the drive reducer 14 is connected to the main drive wheel 16 via a main drive chain 15. Because each head pulley 5 is located above the liquid level, the immersion tanks in the same direction share the drive shaft 4, eliminating the problem of extractant leakage and ensuring that the scraper chains 6 at each level operate in complete synchronization.

[0087] The lower end of each group of scraper chains 6 is wrapped around the tail wheel 8, which is immersed in the extraction liquid and located at the lowest end of the immersion tank. The load is extremely light. Each tail wheel 8 is fixed to the middle of its own driven short shaft 9. The two ends of each driven short shaft 9 are supported in the driven bearing seat 12 through sliding bearings 11. The outer port of the driven bearing seat 12 is covered with a sealing blind cover 13. The inner convex ring of the sealing blind cover 13 is embedded in the outer port of the driven bearing seat 12. The flange edge of the sealing blind cover 13 is pressed and fixed to the outer periphery of the driven bearing seat 12 by a sealing gasket.

[0088] The driven bearing seat 12 is fixed to the center hole of the driven shaft end plate 10. The outer flange of the driven bearing seat 12 is compressed and secured to the driven shaft end plate 10 via a gasket. The flange edge of the driven shaft end plate 10 is also secured to the longitudinal partitions of the adjacent soaking tanks via a gasket. Thus, each driven stub shaft 9 is arranged in sections, located at the bottom of each soaking tank. Both ends are completely sealed to the longitudinal partitions of the soaking tanks, eliminating the risk of soaking liquid leaking between adjacent soaking tanks and ensuring effective extraction.

[0089] The material conveying process of the transmission mechanism is highly consistent with the mass transfer principle: the extraction liquid level in the equipment is fixed, and the bottom wall of the immersion tank is set at an angle. Each stage of the conveying process includes the following actions: the drained material is mixed again with the low-concentration extraction liquid for direct mass transfer, the extraction material layer is reconstructed on the inclined bottom of the immersion tank, and a weak stirring effect is achieved under the push and sweep of the scraper to achieve mass transfer. The solute is discharged as much as possible during the drainage process from the liquid surface, which provides a guarantee for further reducing the solute concentration and maintaining the extraction power.

[0090] As shown in Figures 12 to 14, the temporary storage feeding device includes a temporary storage bucket 1 and a feeding valve. The temporary storage bucket 1 is conical in length and width, with a narrow upper end and a wide lower end. The upper end of the temporary storage bucket 1 is provided with a feed port 1a, and the lower end of the temporary storage bucket 1 is installed with a feeding valve 2.

[0091] The feeding valve 2 comprises a valve body 2a, a feeding motor 2b, a feeding reduction mechanism 2c, a feeding chain 2d, a feeding drive wheel 2e, a synchronous gear 2f, an impeller shaft 2g, and feeding blades 2h. Two parallel impeller shafts 2g are arranged along the length of the feeding valve 2. The feeding blades 2h are radially distributed around the outer periphery of the impeller shafts 2g, extending along their length and located within the inner cavity of the valve body 2a. The outer edges of the feeding blades 2h point toward the outer walls of the adjacent impeller shafts 2g, and the feeding blades 2h on adjacent impeller shafts 2g interlock.

[0092] The upper port of the valve body 2a is rectangular and docks with the lower port of the temporary storage bucket 1. The lower port of the valve body 2a is rectangular and docks with the feed port of the extractor. The valve body 2a is provided with an arc-shaped side wall in the length direction to match the rotation circle of the feeding blade 2h.

[0093] Synchronous gears 2f are respectively installed on the same side shaft ends of the two impeller shafts 2g. The two synchronous gears 2f are engaged with each other, so that the two impeller shafts 2g rotate synchronously in opposite directions and maintain a fixed phase difference.

[0094] The feeding reduction mechanism 2c is fixed to the outer wall of the valve body 2a. The high-speed input end of the feeding reduction mechanism 2c is driven by the feeding motor 2b, and the low-speed output end is connected to the feeding drive wheel 2e through the feeding chain 2d or the synchronous belt. The feeding drive wheel 2e is installed on the other side of the active impeller shaft 2g.

[0095] The impeller shaft includes a coaxial core shaft 2g1 and a steel pipe 2g2. The steel pipe 2g2 is sleeved on the outer circumference of the core shaft 2g1. The two ends of the steel pipe 2g2 are welded to the outer circumference of the core shaft 2g1 through an annular web 2g3 and are coaxial. The root of the feeding blade is welded to the outer wall of the steel pipe 2g2.

[0096] At least two annular ribs 2j are symmetrically welded to the outer wall of the steel pipe 2g2. The annular ribs 2j pass through the notches of each feeding blade and are welded together to improve the strength of the feeding blade 2h.

[0097] The working process of this temporary feeding device is as follows:

[0098] Raw material enters the temporary storage hopper 1 through feed port 1a, where it gradually accumulates, forming an inverted conical column. This column maintains a constant height, sealing the medium within the extractor. Feed motor 2b is activated, and after being decelerated by feed reduction mechanism 2c, it drives feed drive wheel 2e via feed chain 2d. Feed drive wheel 2e drives the active impeller shaft 2g, which in turn rotates in the opposite direction via synchronous gear 2f. The material fills the grooves between feed blades 2h. The two impeller shafts 2g rotate outward on the upper portion of valve body 2a to prevent compression. After passing through the valve body arc, the material rotates to the bottom of the impeller, where it falls under the influence of gravity. The impeller speed is adjusted by variable frequency control of feed motor 2b, which is strictly proportional to the feed rate, enabling precise control of the feed rate.

[0099] The relative positions of the two impellers are determined by two synchronous gears 2f, and a fixed phase difference is maintained between them, which is equal to half of the angle between two adjacent feeding blades 2h. The two impellers produce counter-rotation similar to meshing, which plays the role of mutual self-cleaning.

[0100] The impeller has a short blade open structure, and the feed blades are 2h long without sealing plates at both ends. This is an open structure to avoid the gap between the sealing plate and the valve body end cover, which may cause material jamming during operation and high friction. The open impeller can eliminate the jamming phenomenon.

[0101] The tooth-shaped grooves formed by the feeding blades 2h and the steel pipe 2g2 serve as the feed channel. The grooves are shallow and generally less prone to siltation, allowing for precise feeding. Even if there is occasional material in the grooves, the meshing of the two impellers allows for self-cleaning.

[0102] The extraction method of the staggered scraper extractor of the present invention comprises the following steps in sequence:

[0103] A1. Fresh solvent first falls on the upper part of the chain partition of the final soaking tank, flows downward and rightward, and covers the entire width of the chain partition. It then falls through the slit like a waterfall and enters the soaking space between the final chain partition and the inclined bottom wall. It flows downward and rightward, washing the powder moving in the opposite direction and performing the final extraction. After reaching the bottom of the final soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then turns upward and flows leftward.

[0104] A2. The extract flows from the interstage overflow port of the final stage into the bottom of the chain partition of the previous soaking tank, then into the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and leftward to extract the powder moving in the opposite direction. After reaching the bottom of this soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then flows upward and rightward.

[0105] A3. The extract flows from the interstage overflow port of this stage into the lower part of the chain partition of the upper soaking tank, then into the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and rightward to extract the powder moving in the opposite direction. After reaching the bottom of the soaking tank of this stage, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, then flows upward and leftward.

[0106] A4. The extract then enters the immersion space between the chain partition and the inclined bottom wall of the previous stage from the interstage overflow port, and so on;

[0107] A5. After the extract reaches the bottom of the first-stage immersion tank, it bypasses the lower edge of the chain partition and flows upward from the concentrated solvent outlet.

[0108] The temporary feeding device feeds new materials into the first-stage immersion tank and they fall on the chain partition. They are pushed downward and rightward by the scraper and immersed under the liquid surface. After reaching the bottom of the first-stage immersion tank, they turn and enter the immersion space between the chain partition and the inclined bottom wall, move upward and leftward, and are extracted. After gradually drying out of the liquid surface, they continue to move upward and leftward and drain.

[0109] The material drained in the first stage slides horizontally from the upper part of the inclined bottom wall of the first stage into the lower end of the second stage soaking tank, moves upward and rightward along the soaking space between the chain partition and the inclined bottom wall of this stage and is extracted. After gradually drying out of the liquid surface, it continues to move upward and rightward and drain, and slides horizontally from the upper part of the inclined bottom wall into the lower end of the third stage soaking tank, and so on.

[0110] The material on the upper end of the inclined bottom wall of the final soaking tank falls into the lower end of the draining tank, climbs along the inclined bottom wall of the draining tank and is finally drained, and then discharged to the material outlet through the discharge chute.

[0111] The above description is only a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may have other implementation modes without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. Technical features not described in the present invention can be achieved by or using existing technologies, and will not be described here.

Claims

1. A staggered scraper extractor, comprising a box, characterized in that: The box body is provided with a plurality of longitudinal partitions extending along the length direction of the box body and parallel to each other, and each longitudinal partition divides the box body into a plurality of soaking pools arranged side by side and connected in series in the width direction; each soaking pool is provided with an inclined bottom wall, and the inclined directions of the inclined bottom walls of adjacent soaking pools are opposite, and each soaking pool is provided with an annular chain scraping mechanism, and a temporary storage feeding device is installed above the first-stage soaking pool.

2. The staggered scraper extractor according to claim 1, characterized in that: A chain partition is provided above each inclined bottom wall, and each chain partition is parallel to the inclined bottom wall below. The upper layer of the chain scraper mechanism descends along the corresponding chain partition, and the lower layer of the chain scraper mechanism scoops out the material from the bottom of the corresponding immersion pool, drains it, and pushes it upward along the inclined bottom wall.

3. The staggered scraper extractor according to claim 2, characterized in that: The upper end of each inclined bottom wall is respectively provided with a transverse chute for guiding materials to the lower end of the next-level soaking pool.

4. The staggered scraper extractor according to claim 3, characterized in that: A transverse main inclined chute for guiding materials to the lower end of the next soaking pool is provided at the position near the upper end of each inclined bottom wall; and a transverse auxiliary inclined chute for guiding materials to the lowest point of the next soaking pool is provided at the uppermost end of each inclined bottom wall.

5. The staggered scraper extractor according to claim 4, characterized in that: The angle between the bottom wall of the transverse main inclined chute and the transverse auxiliary inclined chute and the horizontal plane is greater than 60°, and the angle between the inclined bottom wall and the horizontal plane is less than 15°.

6. The staggered scraper extractor according to claim 2, characterized in that: An interstage overflow port for overflowing to the upper soaking pool is provided in the middle section of the adjacent longitudinal partitions. The interstage overflow ports are respectively located above the chain partition of the current stage and below the chain partition of the upper stage.

7. The staggered scraper extractor according to claim 6, characterized in that: The interstage overflow ports of two connected stages are staggered with each other in the length direction of the soaking tank.

8. The staggered scraper extractor according to claim 6, characterized in that: A fresh solvent replenishing inlet is arranged above the upper part of the chain partition in the final immersion tank, and a slit for the solvent to pass through is arranged above the liquid level of the final chain partition; a concentrated solvent outflow outlet is arranged on the box wall at the lowest end of the first immersion tank.

9. The staggered scraper extractor according to claim 8, characterized in that: The fresh solvent first falls on the upper part of the chain partition of the final soaking tank, and covers the full width of the chain partition during the downward and rightward flow, and then falls from the slit like a waterfall, enters the soaking space between the final chain partition and the inclined bottom wall, and flows downward and rightward to wash and extract the powder moving in the reverse direction. After reaching the bottom of the final soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and leftward; The extracting liquid enters the lower part of the chain partition of the upper soaking tank from the interstage overflow port of the last stage, enters the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and leftward to extract the powder moving in the reverse direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and rightward; The extract enters the bottom of the chain partition of the upper soaking tank from the interstage overflow port of this stage, enters the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and rightward to extract the powder moving in the opposite direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the top of the chain partition, then flows upward and leftward; then it enters the upper stage from the interstage overflow port, and so on.

10. The staggered scraper extractor according to claim 6, characterized in that: A first-stage draining tank is also arranged outside the final soaking tank. The longitudinal partition between the draining tank and the final soaking tank is a closed structure below the liquid level. A chute is arranged at the upper end of the inclined bottom wall of the draining tank and connected to the material outlet.

11. The staggered scraper extractor according to claim 1, characterized in that: The chain scraper mechanism includes a scraper chain and a scraper evenly fixed on the scraper chain. The upper end of each group of scraper chains is wrapped around the head wheel and is located above the liquid level. The lower end of each group of scraper chains is wrapped around the tail wheel and immersed in the extraction liquid. The head wheels located at the same end of the extractor are commonly fixed on the corresponding driving long shafts. The shaft ends of the two driving long shafts are respectively installed with main driving wheels, and the two main driving wheels are respectively driven by their own scraper driving mechanisms.

12. The staggered scraper extractor according to claim 11, characterized in that: Each tail wheel is fixed to the middle of its own driven short shaft, and both ends of each driven short shaft are supported on the bottom of the longitudinal partition of the adjacent soaking tank through bearings.

13. The staggered scraper extractor according to claim 12, characterized in that: The shaft end of the driven short shaft is supported in a sliding bearing, the sliding bearing is embedded in a driven bearing seat, the outer port of the driven bearing seat is covered with a sealing blind cover, the driven bearing seat is sealed and fixed at the center hole of the driven shaft end plate, and the driven shaft end plate is sealed and fixed on the corresponding longitudinal partition.

14. The staggered scraper extractor according to claim 1, characterized in that: The temporary storage feeding device comprises a temporary storage bucket, which is tapered in length and width directions and narrow at the top and wide at the bottom. A feeding valve is installed at the lower port of the temporary storage bucket, and the feeding valve comprises: The impeller shafts are provided with two parallel shafts, and extend along the length direction of the feeding valve respectively; The feeding blades are evenly distributed radially on the outer periphery of the impeller shaft, located in the inner cavity of the valve body and extending along the length direction of the impeller shaft respectively, the outer edges of each feeding blade point to the outer wall of the adjacent impeller shaft respectively, the feeding blades on the adjacent impeller shafts are cross-engaged and the phase difference is half of the angle between two coaxial adjacent feeding blades; The valve body has a rectangular shape on the upper and lower ports, and has an arc-shaped side wall in the length direction to match the rotation circle of the feeding blade; Synchronous gears are respectively mounted on the same side shaft ends of the two impeller shafts and mesh with each other to make the two impeller shafts rotate synchronously in opposite directions; The driving wheel is installed on the other side of one of the impeller shafts. The feeding speed reduction mechanism has an input end driven by a feeding motor and an output end driving the driving wheel through a chain or a synchronous belt.

15. An extraction method using a staggered scraper extractor, using the staggered scraper extractor as claimed in claim 8, characterized in that: The steps are as follows: A1. The fresh solvent first falls on the upper part of the chain partition of the final soaking tank, and covers the full width of the chain partition during the downward and rightward flow. Then, it falls from the slit like a waterfall, enters the soaking space between the final chain partition and the inclined bottom wall, and flows downward and rightward to wash and extract the powder moving in the reverse direction. After reaching the bottom of the final soaking tank, the solvent bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and leftward. A2. The extract enters the lower part of the chain partition of the upper soaking tank from the interstage overflow port of the last stage, enters the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and leftward to extract the powder moving in the reverse direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and rightward; A3. The extract enters the lower part of the chain partition of the upper soaking tank from the interstage overflow port of this stage, enters the soaking space between the chain partition and the inclined bottom wall of this stage, and flows downward and rightward to extract the powder moving in the reverse direction. After the solvent reaches the bottom of the soaking tank of this stage, it bypasses the lower edge of the chain partition and enters the upper part of the chain partition, and then flows upward and leftward; A4, the extract then enters the immersion space between the chain partition and the inclined bottom wall of the previous stage from the interstage overflow port, and so on; A5. After the extract reaches the bottom of the first-stage immersion tank, it bypasses the lower edge of the chain partition and flows upward from the concentrated solvent outlet.

16. The extraction method of the staggered scraper extractor according to claim 15, characterized in that: The temporary feeding device feeds new materials into the first-stage soaking tank and drops them on the chain partition. The materials are pushed downward and rightward by the scraper and immersed under the liquid surface. After reaching the bottom of the first-stage soaking tank, they turn and enter the soaking space between the chain partition and the inclined bottom wall, move upward and leftward, and are extracted. After gradually drying out of the liquid surface, they continue to move upward and leftward and drain. The first-stage drained material slides horizontally from the upper part of the first-stage inclined bottom wall into the lower end of the second-stage soaking tank, moves upward and rightward along the soaking space between the chain partition and the inclined bottom wall of this stage and is extracted, and after gradually drying out of the liquid surface, continues to move upward and rightward and drain, and slides horizontally from the upper part of the inclined bottom wall into the lower end of the third-stage soaking tank, and so on; The material on the upper end of the inclined bottom wall of the final soaking tank falls into the lower end of the draining tank, climbs along the inclined bottom wall of the draining tank and is finally drained, and then discharged to the material outlet through the discharge chute.

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