Volute type sedimentation system

Abstract

The invention relates to the technical field of sugar industry, and discloses a worm type sedimentation system which comprises a settler barrel, a negative pressure steam dispersing box, a retarder, a worm type backflow plate, a step-by-step thickening mud scraping mechanism, a mud collecting barrel and an I-shaped juice outlet ring groove. Compared with an existing settler, the device is characterized in that a juice inlet buffer is arranged at the upper part of the center of a worm type backflow plate of the settler, heated cane juice flows out through a negative-pressure steam dispersing box, and the cane juice enters the buffer tangentially after being added with an auxiliary agent and fully mixed, and enters a limited worm type backflow plate along the umbrella-shaped edge of the buffer; the liquid flow gradually settles outwards along the worm type backflow plate, and mud juice generated in the settling process is accumulated at the cone bottom; mud juice is discharged into the mud collecting barrel through the step-by-step thickening mud scraping mechanism and flows out of the mud discharging opening. Clarified juice flows out from a juice outlet ring groove in the periphery of the worm type backflow plate. The device can reduce the retention time of the cane juice in the settler, and has the characteristics of less sucrose conversion, high mud juice concentration, transparent clear juice, small equipment occupied area, large squeezing resistance fluctuation range and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of the sugar industry, and particularly to a spiral settling system. Background Art

[0002] In the technical field of the sugar industry, settlers are divided into two categories: multi-layer and single-layer settlers. For traditional multi-layer settlers, the residence time of sugar juice in the apparatus is too long, the process temperature is too high during sedimentation, and the pH value is not properly adjusted, which easily causes the destruction of reducing sugar or the conversion of sucrose. The single-layer rapid settler has the advantages of simple structure, large processing capacity, relatively small equipment volume, and relatively short sedimentation time, reducing sugar loss to a certain extent, but there are more fine particle suspensions in the clear juice.

[0003] Among the technologies known to the public at home and abroad, such as the utility model patent ZL201320058033.2, this patent proposes a single-layer rapid settler. An annular juice inlet trough is provided in the upper part of the cylinder body, and an annular baffle is provided in the cylinder body below the trough. The sugar juice slowly and evenly flows into the lower part of the cylinder body through the annular juice inlet trough, stably settles in each annular baffle, the juice outlet quality is good, the residence time of the sugar juice in the settler is shorter than that of other settlers, the sludge discharge is firm, the sludge volume is reduced, and the reflux amount is also reduced accordingly, reducing the burden of subsequent filtration and reprocessing.

[0004] The utility model patent ZL201020129790.0, a single-layer juice filtering rapid settler for the sugar industry, includes a direct heater, a buffer steam release box, and a rapid sedimentation separator. The rapid sedimentation separator is provided with a sedimentation device, a clear juice collection device, and a sludge scraping device. The sedimentation device is composed of a juice inlet dosing mixing box, a juice inlet distribution trough, and a sedimentation trough. The clear juice is designed to be discharged in a single layer.

[0005] The utility model patent ZL201020060907.4, a double-layer rapid settler for neutralized juice, is composed of a buffer steam release system and a rapid sedimentation separator. The sedimentation trough of the rapid sedimentation separator is designed with a buffer diversion trough, and the clear juice is designed to be discharged in a double-layer adjustable manner, which can adjust the sedimentation liquid level according to the production situation, avoiding the shutdown losses caused by poor sedimentation due to production fluctuations, inability to discharge juice, or failures in subsequent processes and production interruptions. It has the advantages of rapid sedimentation of a single-layer rapid settler and the buffering function of a multi-layer settler.

[0006] The utility model patent ZL201410165193.6, the present invention provides a rapid settler for sugar clarification. The cylinder body is composed of a cylinder and a conical hopper. An overflow trough is designed in the inner cavity at the upper end of the cylinder body, and the overflow trough is connected to the clear juice outlet. The lower end of the cylinder body is connected to the mud juice outlet pipe; a cane juice deflector is provided, which is in an inverted funnel shape, and the cane juice deflector is placed in the cavity of the cylinder body. The rapid settler has obvious clarification effect, good flocculation effect, fast sedimentation, clear juice outlet, and less floating scum.

[0007] Utility model patent ZL201420398204.0. The utility model provides an efficient multi-layer rapid settler, which includes a buffer steam-dispersing system, a chemical dosing system, and a multi-layer rapid settler body. The juice inlet chemical mixing tank is connected to the secondary buffer steam-dispersing tank; the multi-layer rapid settler body includes a settler tank body, a central rotating shaft arranged in the middle of the settler tank body, and N-layer sedimentation systems surrounding the outside of the central rotating shaft. Each layer of sedimentation in this efficient multi-layer rapid settler can separately inlet and outlet juice, with good clarification effect and stable operation.

[0008] For the settlers proposed by the above patent technologies, in actual production, there are problems such as a significant increase in the fine suspended matter in the clarified juice after using for a period of time, the conversion of sucrose due to the too large volume capacity of the container design resulting in too long effective residence time, the agitation of the mud juice caused by the large-area swirling sweep of the traditional mud scraper leading to the turbidity of the clarified juice, and the low concentration of the mud juice. How to improve the clarification effect of the settler, reduce the residence time of the cane juice and the conversion of sucrose, and increase the concentration of the mud juice have become effective consideration indicators for measuring the performance of the rapid settler. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to eliminate the conversion of sucrose caused by the too long residence time of the cane juice in the settler, reduce the disturbance of the clarified juice by the traditional mud scraper, and physically concentrate the mud juice concentration, reduce the treatment pressure of the subsequent processes and the problem of too many suspended matters in the clarified juice.

[0010] To solve the above technical problems, the present invention proposes a spiral settler system, which has good clarified juice effect, short effective residence time of the cane juice, less conversion of sucrose, high concentration of the mud juice, reduces the treatment pressure of the subsequent processes, and has stable and reliable operation.

[0011] The technical solution adopted by the present invention is: A spiral settler system includes a settler cylinder, a negative pressure steam-dispersing tank, a retarder, a spiral reflux plate, a gradually thickening mud scraping mechanism, a mud collecting cylinder, and a I-shaped juice outlet ring groove. Compared with the existing settler, its characteristics are: an inlet juice retarder is arranged above the center of the spiral reflux plate of the settler. After heating, the cane juice flows out from the negative pressure steam-dispersing tank. After the cane juice is fully mixed with additives, it tangentially enters the retarder and enters the limited spiral reflux plate along its umbrella-shaped edge; the liquid flow gradually settles outward along the spiral reflux plate, and the mud juice generated during the settlement accumulates at the conical bottom; the mud juice is discharged through the gradually thickening mud scraping mechanism and flows out from the mud discharge port of the mud collecting cylinder; the clarified juice flows out from the juice outlet ring groove outside the spiral reflux plate.

[0012] Optimization scheme: The spiral reflux plate adopts a logarithmic spiral plate line structure. Flocculants will be generated in the cane juice after adding additives. The flocculant particles in the cane juice are forced to be fully mixed along the spiral direction of the spiral reflux plate, resulting in collision aggregation, clarification, and settlement. The clarified juice enters the I-shaped juice outlet ring groove from the outermost periphery of the spiral plate.

[0013] Further optimization: Add a step-by-step thickening sludge scraping mechanism. The blades of this mechanism adopt a logarithmic spiral plate line structure, enabling the sedimented molasses to gradually concentrate towards the middle under the slow pushing and peristaltic action of the sludge scraping mechanism and slowly flow into the sludge collection cylinder.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The sedimentation area is the main design parameter of the settler. Theoretically, the larger the sedimentation area, the better the clarification effect. The current mainstream design method for the sedimentation system is to ensure the clarification effect and handle the fluctuating amount of cane juice by increasing the area (or volume) of the sedimentation tank body. In order to ensure an increase in the sedimentation area within a limited volume without affecting the clarification effect and the amount of cane juice processed, the present invention has set a spiral volute plate (4) with a logarithmic spiral line structure in the middle of the settler cylinder. When the cane juice overflows from the upper edge of the retarder (6) and flows into the inner circle of the volute plate (4), a sealing plate (12) is provided at the end of the inner circle, and the flocculent particles in the cane juice are forced to flow along the rotation direction of the spiral volute plate. During the flow of the cane juice, the suspended particulate matter in the cane juice repeatedly undergoes tangential rotational collisions, agglomeration, and molasses spiral sedimentation movements in the spiral volute plate. The deposition of the coarse-grained flocculent matter in the cane juice is in the middle area of the cone bottom, while the fine suspended particulate matter continues to move towards the outer circle along the spiral volute plate. Under the action of its own pure physical movement, the fine suspended particulate matter advances along a rolling spiral collision route. The fine particles continuously agglomerate with the flocculent matter into large particles, and then under the action of gravity, gradually rotate and deposit in the area outside the center of the cone bottom away from the central area. In the existing design scheme, under the ideal condition that the height of the cylinder remains unchanged, whether the juice enters from the side or the middle, the maximum distance that the cane juice travels in the plane is the diameter of the tank body; while with the setting of the logarithmic spiral volute plate structure, the shortest path that the cane juice travels is the circumference of the equidistant spiral line. Within a limited volume, the distance it travels increases several times, increasing the physical full mixing of the flocculent particles and the sedimentation distance of the flocculent matter, separating the sedimentation areas of the fine particulate matter and the large particulate matter, greatly reducing the usage amount of the flocculant in the process, thereby reducing the capacity of the effective volume, greatly reducing the floor area of the equipment, and reducing the manufacturing production cost of the equipment.

[0015] 2. Setting of the stepwise thickening sludge scraping device: Driven by a reduction motor (5), the juice sludge gradually settling at the conical bottom is slowly pushed into the sludge collection cylinder (10), and the blades of the stepwise thickening sludge scraping mechanism (8) adopt a logarithmic spiral structure. The advantages of the sludge scraping device of the present invention are as follows: When the sugarcane juice settles, most of the initially settled sludge juice, due to the large flocculated particulate matter clusters, is close to the center of the conical bottom of the settler; while the dilute sludge juice settles at the outermost periphery of the sludge collection cylinder, that is, in the middle of the logarithmic spiral scraper. When the thickening sludge scraping device rotates slowly, using the relevant principles of the logarithmic spiral, the scraper slowly pushes the dilute sludge juice towards the middle of the second-layer scraper, and the intermediate sludge juice is gradually squeezed into the sludge collection cylinder. Compared with the traditional high-hung large scraper, which causes large-area swirling disturbance to the already stratified sludge layer and makes the clear juice turbid; while the present sludge scraping solution causes little disturbance to the sludge juice, and the sludge juice is pushed from the low-concentration area to the high-concentration area, and the pure physical extrusion thickening makes the sludge juice denser.

[0016] 3. Setting of the negative pressure steam dispersing box: The sugarcane juice flows out from the negative pressure steam dispersing box (3) and tangentially enters the retarder (6) through a pipeline. The retarder (6) is internally provided with a deceleration orifice plate (11). After the sugarcane juice decelerates, it gradually overflows the upper edge of the retarder, and an umbrella-shaped edge is provided at the edge to enter the spiral reflux plate. The innovative design of this part of the solution lies in: (a) The setting of the negative pressure steam dispersing box, and its barrel body adopts an unequal-diameter structure. The establishment of the micro-negative pressure system in the steam dispersing box accelerates the escape of bubbles in the hot sugarcane juice, facilitating the addition of flocculants and the fully mixed sugarcane juice, avoiding the flocs floating on the surface of the clear juice layer in the settler, and accelerating the sedimentation speed of the flocs. (b) The sugarcane juice tangentially enters the retarder (6) and passes through the deceleration orifice plate (11), reducing the impact of the incoming juice in the settler. The sugarcane juice overflowing upward through the orifice plate enters the spiral reflux plate along the edge of the umbrella-shaped opening. The setting of the angle of the annular umbrella-shaped plate is equivalent to an annular deflector, enabling the sugarcane juice to enter the pool body along the inner wall of the spiral reflux plate, avoiding the static impact of the secondary impact of the sugarcane juice on the bottom of the pool body.

[0017] (4) Setting of the I-shaped juice outlet ring groove: The position of the I-shaped juice outlet ring groove (2) is far from the juice inlet center, so that the clear juice avoids the impact of the sugarcane juice entering the sedimentation pool body. The blocking design of the spiral reflux plate enables the sugarcane juice to enter the clear juice ring groove evenly from the periphery of the spiral reflux plate after clarification, avoiding the disturbance impact of the change in the amount of sugarcane juice on the clear juice, and enhancing the static stability of the clarified juice in the pool body. The innovative advantage of using the I-shaped ring groove outlet for the juice outlet ring groove is that when the squeezing amount increases, the clear juice outlet area increases with the increase in the liquid level, thereby increasing the outflow of the clear juice; conversely, the clear juice outlet decreases with the decrease in the squeezing amount, automatically adjusting the squeezing amount fluctuation, with strong anti-fluctuation ability, and eliminating the safety setting of the overflow pipe. Description of the Drawings

[0018] Figure 1 It is the front view of the spiral settler system of the present invention.

[0019] Figure 2This is a top view of the spiral settlement system of the present invention.

[0020] Figure 3 This is a top view of the spiral reflux plate of the spiral settlement system of the present invention.

[0021] Figure 4 This is a front view of the stepwise thickening sludge scraping device of the spiral settlement system of the present invention.

[0022] Figure 5 This is a 3D view of the stepwise thickening sludge scraping device of the spiral settlement system of the present invention. Embodiment

[0023] The present invention will be further described below with specific embodiments.

[0024] Reference Figure 1 and Figure 2 、 Figure 3 、 Figure 4 and Figure 5 A spiral settlement system proposed by the present invention includes a settler cylinder (1), a retarder (6), a negative pressure steam dispersing box (3), a spiral reflux plate (4), a stepwise thickening sludge scraping mechanism (8), a sludge collecting cylinder (10), an I-shaped juice outlet ring groove (2), etc. Its characteristics are as follows: The heated cane juice passes through the negative pressure steam dispersing box (3), and after being mixed with the flocculant, it tangentially flows into the bottom of the retarder (6). The retarder (6) is fixed at the center of the spiral reflux plate (4), and the spiral reflux plate (4) is placed on the bottom bracket (7); the cane juice overflows the orifice plate (11) of the retarder and flows along its umbrella-shaped edge into the spiral reflux plate (4). The cane juice gradually clarifies and settles along the spiral direction of the spiral reflux plate. The clarified clear juice flows out through the I-shaped juice outlet ring groove (2); the thickening sludge scraping mechanism (8) is driven to rotate by a reduction motor (5), and the settled muddy juice is discharged into the sludge collecting cylinder (10) in a stepwise concentration and extrusion manner and flows out through the muddy juice outlet.

[0025] Figure 1 This is a front view of the spiral settlement system of the present invention, Figure 2 is Figure 1Top view. First, the cane juice is heated by a heater and then enters the negative-pressure steam-dispersing tank (3). After the steam is dispersed, the cane juice enters the retarder (6) in the sedimentation tank body. Before entering the retarder (6), a flocculant should be added to the outlet pipe of the negative-pressure steam-dispersing tank (3). Driven by the cane juice, the flocculant is mixed and reacted in the pipe and then enters the retarder (6). The retarder (6) is a hollow cylindrical structure with a sealed bottom and an orifice plate in the middle. The aperture of the orifice plate is 30 - 60 mm, and the number of holes should ensure that the flow-through area is larger than the actual required flow-through area of the juice volume, generally more than 3 times is appropriate. The cane juice overflows through the orifice plate, slowing down the impact speed of the cane juice. The upper edge of the retarder (6) is provided with an outward umbrella-shaped lip. The included angle of the lip is about 30° - 70°, and the length of the lip is not less than 150 mm. The size of the included angle and the length of the lip are related to the inner diameter of the volute-shaped plate, ensuring that the flowing-out cane juice reaches the middle section of the volute-shaped plate wall under the self-flow speed through the diversion of the skirt plate, which helps to reduce the liquid flow impact in the initial stage of starting the sedimentator.

[0026] Figure 2 is the top view of the volute-type sedimentation system of the present invention, Figure 3 is the top view of the volute-type reflux plate (4). The diameter, number of turns, and plate spacing of the volute-type reflux plate (4) are related to the processing capacity of the sedimentator. The retarder (6) is welded to the volute-type reflux plate through a connecting piece to ensure its fixation at the center of the volute-type reflux plate (4). At the starting point of the volute-type reflux plate (4), a plate member is used to connect the retarder (6), which is beneficial for the overflowing cane juice to perform logarithmic spiral sedimentation according to the guidance of the volute-type reflux plate. Connecting pieces in the other three directions can adopt perforated plates or connecting rods to facilitate the flow of cane juice. The volute-type reflux plate (4) is installed on the bottom bracket (7). The bracket beam is welded to the tank body. The bracket beam is fixed in two layers, respectively placed above and below the volute-type reflux plate (4). The top of the sedimentator needs to adopt a conical top cover plate, and an observation port and a steam-dispersing pipe are reserved on the cover plate. The observation port is beneficial for checking the clarification situation, and the setting of the steam-dispersing pipe is beneficial for the secondary discharge of excessive steam in the sedimentator.

[0027] Figure 4 is the front view of the step-by-step thickening sludge scraping device (8) of the present invention, Figure 5 is Figure 4 3D view of. The sludge scraping device of the sedimentator adopts a volute-type scraper. The center of the rotation axis of the scraper passes through the retarder (6), and the bottom of the axis is supported in the bearing seat of the sludge collecting cylinder (10). The height H of the scraper is determined by the thickness h of the sedimented muddy juice layer and is inversely proportional to the rotation speed of the sludge scraping mechanism. Generally, the value of H is 50 - 100 mm. The inner diameter of the sludge scraping device is slightly larger than the diameter of the sludge collecting cylinder. From the sludge scraping device Figure 4As can be seen from the front view, the sludge scraper is in the shape of an inverted truncated cone, and the angle of its cone bottom is equal to that of the cone bottom of the settler, generally taking 8° - 25°. The scraper is connected to the sludge scraping shaft by a connecting rod, and each connecting rod forms a triangular structure with the sludge scraping shaft, which is beneficial to enhancing its rigidity and the stability between the entire scrapers. The end point of the outermost scraper needs to be welded with an inclined scraper, which is 30 mm away from the pool wall, facilitating the diversion of the outermost sludge juice into the outer circle of the scraper for slow concentration. When the sludge scraping shaft rotates slowly, the sludge juice in the outer circle slowly squeezes into the inner circle along the rotation of the scraper. After rotating one circle, the sludge juice moves a spaced distance towards the center of the settler, causing little static disturbance to the pool body.

[0028] The above is a preferred embodiment of the present invention, but the embodiments of the present invention are not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A spiral settlement system, comprising a settlement cylinder body (1), a retarder (6), a negative pressure steam dispersing box (3), a spiral reflux plate (4), a step-by-step thickening sludge scraping mechanism (8), a sludge collecting cylinder (10), an I-shaped juice outlet ring groove (2), etc. It is characterized in that: The heated cane juice passes through the negative pressure steam dispersing tank (3), and after being mixed with the flocculant, it tangentially flows into the bottom of the retarder (6). The retarder (6) is fixed at the center of the spiral reflux plate (4), and the spiral reflux plate (4) is placed on the bottom bracket (7); the cane juice overflows the orifice plate (11) of the retarder and flows along its umbrella-shaped edge into the spiral reflux plate (4). The cane juice gradually clarifies and settles along the spiral direction of the spiral reflux plate. The clarified juice flows out through the I-shaped juice outlet ring groove (2); the thickening sludge scraping mechanism (8) is driven to rotate by the reduction motor (5), and the settled sludge juice is discharged into the sludge collecting cylinder (10) in a gradually thickening and pushing manner and flows out through the sludge juice outlet.

2. The equipment according to claim 1 of the patent right, characterized in that: The spiral reflux plate (4) adopts an Archimedean logarithmic spiral structure. The cane juice overflows from the upper edge of the retarder (6) and flows into the middle of the spiral reflux plate (4), and gradually undergoes forced settlement and clarification along the spiral direction of the spiral plate.

3. The equipment according to claim 1 of the patent right, characterized in that: The reduction motor (5) drives the gradually thickening sludge scraping device (8) to push the settled sludge juice at the conical bottom into the sludge collecting cylinder (10), and the blades of the sludge scraping mechanism adopt a logarithmic spiral structure.

4. The equipment according to claims 1 and 3 of the patent right, characterized in that: One or two bottom sweeping blades (9) are suspended between the spiral blades of the gradually thickening sludge scraping device (8).

5. The equipment according to claim 1 of the patent right, characterized in that: The heated cane juice tangentially enters the negative pressure steam dispersing tank (3), and the negative pressure steam dispersing tank has a structure of a non-uniform diameter box body.

6. The equipment according to claims 1 and 2 of the patent right, characterized in that: The cane juice tangentially enters the retarder (6) through a pipeline, and a reduction orifice plate (11) is installed inside. After the cane juice is decelerated, it gradually overflows the upper edge of the retarder, and the edge has an umbrella-shaped structure.

7. The equipment according to claim 1 of the patent right, characterized in that: An I-shaped juice outlet ring groove (2) is arranged above the inner side of the pool wall of the settler cylinder (1), and a juice outlet is opened on the pool wall to connect to an external clarified juice collecting box and a pipeline outlet.

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