Volute type sedimentation system

Abstract

The utility model 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 invention relates to the technical field of sugar industry, in particular to a spiral sedimentation system. Background Art

[0002] In the field of sugar industry technology, settlers are divided into two categories: multi-layer and single-layer settlers. In traditional multi-layer settlers, the residence time of sugar juice in the device is too long, the process temperature is too high during sedimentation, and the pH value is improperly adjusted, which can easily cause the destruction of reducing sugar or sucrose conversion. The single-layer rapid settler has the advantages of simple structure, large processing capacity, relatively small equipment volume, and relatively short sedimentation time. It reduces sugar loss to a certain extent, but the clear juice has more micro-particles suspended in it.

[0003] Among the technologies known to the public at home and abroad, such as utility model patent ZL201320058033.2, the patent proposes a single-layer rapid settler, in which an annular juice inlet groove is provided in the upper part of the cylinder, and an annular baffle is provided in the cylinder below the groove. The sugar juice is slowly and evenly divided into the lower part of the cylinder through the annular juice inlet groove, and is stably settled in each annular baffle, the juice quality is good, the residence time of the sugar juice in the settler is shorter than that of other settlers, the discharged sludge is firm, the amount of sludge is reduced, and the reflux volume is also reduced, which reduces the burden of later filtration and reprocessing.

[0004] Utility model patent ZL201020129790.0, a single-layer filter juice rapid settler for the sugar industry, includes a direct heater, a buffer vapor box and a rapid sedimentation separator. The rapid sedimentation separator is provided with a sedimentation device, a clear juice collection device and a mud scraping device. The sedimentation device consists of a juice inlet dosing mixing box, a juice inlet distribution tank and a sedimentation tank. The clear juice is designed to be discharged in a single layer.

[0005] Utility model patent ZL201020060907.4, a double-layer rapid settler for neutralized juice, consists of a buffer steam dissipation system and a rapid sedimentation separator. The sedimentation tank of the rapid sedimentation separator is designed with a buffer guide groove, and the clear juice is designed as a double-layer adjustable juice outlet. The sedimentation liquid level can be adjusted according to the production situation, avoiding the downtime loss caused by poor sedimentation and inability to release juice due to production fluctuations or failure of the subsequent process and production interruption. It has the advantages of rapid sedimentation of a single-layer rapid settler and the buffering function of a multi-layer settler.

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

[0007] Utility model patent ZL201420398204.0, this utility model provides a high-efficiency multi-layer rapid settler, including a buffer vapor system, a dosing system and a multi-layer rapid settler body. The juice inlet dosing mixing box is connected to the secondary buffer vapor box; the multi-layer rapid settler body includes a settler tank, a central shaft arranged in the middle of the settler tank, and an N-layer sedimentation system surrounding the outside of the central shaft. Each layer of the high-efficiency multi-layer rapid settler can be independently fed and discharged, with good clarification effect and stable operation.

[0008] The settlers proposed by the above patented technologies all have the problem of significantly increasing the amount of suspended solids in the clear juice after a period of use in actual production. The effective residence time is too long due to the large volume of the container design, which causes the conversion of sucrose. The large-area rotary sweep of the traditional scraper causes the muddy juice to become muddy, and the muddy juice concentration is low. How to improve the clarification effect of the settler, reduce the residence time of the sugarcane juice and the conversion of sucrose, and increase the concentration of the muddy juice have become effective 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 long residence time of sugarcane juice in the settler, reduce the disturbance of clarified juice by traditional scrapers, and physically concentrate the mud juice concentration, reduce the processing pressure of the subsequent process and the problem of a large amount of suspended matter in the clear juice.

[0010] In order to solve the above technical problems, the present invention proposes a spiral sedimentation system, which has good juice clarification effect, short effective residence time of sugarcane juice, less conversion of sucrose, high mud juice concentration, reduced pressure on post-processing, and stable and reliable operation.

[0011] The technical solution adopted by the present invention is:

[0012] A spiral settling system, comprising a settler cylinder, a negative pressure diffuser, a damper, a spiral return plate, a step-by-step thickening and scraping mechanism, a mud collecting barrel and an I-shaped juice outlet ring groove. Compared with the existing settlers, the system is characterized in that: a juice inlet damper is provided at the center upper part of the spiral return plate of the settler, and the heated sugarcane juice flows out through the negative pressure diffuser, and the sugarcane juice is fully mixed after adding additives and then tangentially enters the damper, and enters the limited direction spiral return plate along its umbrella-shaped edge; the liquid flow gradually settles outward along the spiral return plate, and the mud juice generated during the sedimentation process accumulates at the bottom of the cone; the mud juice is discharged into the mud outlet of the mud collecting barrel through the step-by-step thickening and scraping mechanism; the clarified juice flows out from the juice outlet ring groove on the periphery of the spiral return plate.

[0013] Optimization plan: The volute reflux plate adopts a logarithmic spiral plate line structure. After adding additives, the sugarcane juice will produce floccules. The flocculent particles in the sugarcane juice are forced to be fully mixed along the rotation direction of the volute reflux plate, resulting in collision coagulation, clarification and sedimentation. The clear juice enters the I-shaped juice outlet ring groove from the outermost periphery of the volute plate.

[0014] Further optimization: a step-by-step thickening and scraping mechanism is added. The blades of this mechanism adopt a logarithmic spiral plate line structure, so that the settled mud juice is gradually concentrated to the middle under the slow push and creeping action of the scraping mechanism, and slowly flows into the mud collecting barrel.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The sedimentation area is the main design parameter of the settler. In theory, the larger the sedimentation area, the better the clarification effect. The current mainstream sedimentation system design method is to ensure the clarification effect and the processing of fluctuating sugarcane juice by increasing the area (or volume) of the sedimentation tank. In order to ensure that the sedimentation area is increased within a limited volume without affecting the clarification effect and the processing amount of sugarcane juice, the present invention provides a volute return plate (4) with a logarithmic spiral structure in the middle of the settler cylinder. When the sugarcane juice overflows from the upper edge of the damper (6) and flows into the inner circle of the volute plate (4), a sealing plate (12) is provided at the terminal of the inner circle, and the flocculent particles in the sugarcane juice are forced to flow in the direction of rotation of the volute return plate; during the flow of the sugarcane juice, the suspended particles in the sugarcane juice repeatedly undergo tangential rotation collision, clustering and condensation, and spiral sedimentation of mud juice in the volute return plate. The coarse floccules in the sugarcane juice are deposited in the middle area of ​​the cone bottom, while the fine suspended particles continue to move toward the outer circle along the volute return plate. Under the action of its own pure physical movement, the fine suspended particles move forward in a rolling spiral collision route. The fine particles continue to agglomerate with the floccules into large particles, and then gradually rotate away from the central area under the action of gravity and deposit outside the central area of ​​the cone bottom. In the existing design scheme, under the ideal condition that the height of the cylinder remains unchanged, whether the juice is fed from the side or the middle, the maximum distance that the sugarcane juice travels in the plane is the diameter of the pool body; while the logarithmic volute return plate structure is set, the shortest path that the sugarcane juice travels is the circumference of the equidistant spiral line. In a limited volume, the distance it travels is doubled, which increases the physical full mixing of the flocculent particles and the flocculent sedimentation distance, separates the sedimentation area of ​​fine particles and large particles, greatly reduces the amount of flocculant used in the process, thereby reducing the capacity of the effective volume, greatly reducing the equipment footprint, and reducing the manufacturing and production cost of the equipment.

[0017] 2. Setting of the step-by-step thickening and scraping mechanism: driven by the reduction motor (5), the mud juice gradually settled at the bottom of the cone is slowly pushed into the mud collecting barrel (10), and the blades of the step-by-step thickening and scraping mechanism (8) adopt a logarithmic spiral structure, and 1 to 2 bottom sweeping blades (9) are suspended between the spiral blades of the thickening and scraping mechanism. The advantage of the scraping mechanism of the present invention is that when the sugarcane juice settles, most of the mud juice that settles first is close to the center of the cone bottom of the settler due to the large flocculated particle group; while the mud juice with a thin concentration settles at the outermost periphery of the mud collecting barrel, that is, in the middle of the logarithmic spiral scraper. When the thickening and scraping mechanism rotates slowly, the scraper uses the relevant principle of the logarithmic spiral to slowly push the thin mud juice to the middle of the second layer of scrapers, and the mud juice in the middle interval is gradually squeezed into the mud collecting barrel. The bottom sweeping blades suspended between the spiral blades are conducive to promoting the peristalsis of the mud juice settled at the bottom of the cone, avoiding the mud juice from adhering to the bottom of the cone for a long time, producing adverse microorganisms, causing the clear juice to become sour and transform, and affecting the clear juice process indicators. Compared with the traditional high-hanging large scraper, the large-area rotary sweeping disturbance of the stratified and settled mud layer makes the clear juice muddy; the mud scraping scheme has little disturbance to the mud juice, and the mud juice is pushed from the low concentration to the high concentration area, and the pure physical extrusion and concentration makes the mud juice more solid.

[0018] 3. Setting of negative pressure steam box: After heating, the sugarcane juice flows out of the negative pressure steam box (3) and enters the damper (6) tangentially through the pipeline. The damper (6) has a built-in deceleration orifice plate (11). After deceleration, the sugarcane juice gradually overflows the upper edge of the damper, and the edge is provided with an umbrella-shaped edge to enter the volute return plate. The design innovation of this part of the scheme lies in: (a) The setting of the negative pressure steam box, and its cylinder body adopts an unequal diameter structure, and the micro-negative pressure system of the steam box is established, which accelerates the escape of bubbles in the hot sugarcane juice, facilitates the addition of flocculants and fully mixed sugarcane juice, and avoids the floccules floating on the surface of the clear juice layer in the settler, thereby accelerating the sedimentation rate of the floccules. (b) The heated sugarcane juice enters the damper (6) tangentially and passes through the deceleration orifice plate (11), reducing the impact of the incoming juice in the settler. The sugarcane juice that overflows the orifice plate enters the volute return plate along the edge of the umbrella-shaped opening. The setting of the angle of the annular umbrella plate is equivalent to an annular guide plate, which allows the sugarcane juice to enter the tank along the inner wall of the volute return plate, avoiding the static impact of the secondary impact of the sugarcane juice on the bottom of the tank. (c) The use of heated sugarcane juice facilitates the mixing of sugarcane juice with the auxiliary materials added in production, thereby increasing the clarification speed of the sugarcane juice and improving the quality indicators of the clear juice.

[0019] 4. Setting of I-shaped juice outlet ring groove: The position of I-shaped juice outlet ring groove (2) is far away from the juice inlet center, and the clear juice avoids the impact of sugarcane juice entering the sedimentation tank body. The barrier design of the volute return plate allows the sugarcane juice to enter the clear juice ring groove evenly from the periphery of the volute return plate after clarification, avoiding the disturbance of the clear juice by the change of sugarcane juice volume, and enhancing the static stability of the clarified juice in the tank body; and the tank wall is provided with a juice outlet to connect the external clear juice collection box and the pipeline outlet, so that the clear juice can be concentrated and flow out from the juice outlet, and the outlet position can be flexibly set. The innovative advantage of the juice outlet ring groove using an I-shaped outlet is that when the squeezing volume increases, the clear juice outlet area increases with the increase of liquid level, thereby increasing the outflow of clear juice; conversely, the clear juice outlet decreases with the decrease of squeezing volume, automatically adjusting the squeezing volume fluctuation, with strong anti-fluctuation ability, and canceling the safety setting of the overflow pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of the spiral sedimentation system of the present invention.

[0021] Figure 2 It is a top view of the spiral sedimentation system of the present invention.

[0022] Figure 3 It is a top view of the spiral return plate of the present invention.

[0023] Figure 4 A front view of the step-by-step thickening and scraping mechanism of the present invention

[0024] Figure 5 It is a three-dimensional diagram of the step-by-step thickening and scraping mechanism of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with specific embodiments:

[0026] refer to Figure 1 and Figure 2 , Figure 3 , Figure 4 and Figure 5The present invention proposes a spiral sedimentation system comprising a sedimentation vessel body (1), a damper (6), a negative pressure diffuser box (3), a spiral return plate (4), a step-by-step thickening and scraping mechanism (8), a mud collecting cylinder (10) and an I-shaped juice outlet ring groove (2). The invention is characterized in that: the heated sugarcane juice passes through a negative pressure steam diffuser (3), and after being mixed with a flocculant, flows tangentially into the bottom of a damper (6), the damper (6) is fixed at the center of a volute return plate (4), and the volute return plate (4) is placed on a bottom bracket (7); the sugarcane juice overflows the damper orifice plate (11), flows into the volute return plate (4) along its umbrella-shaped edge, and the sugarcane juice gradually clarifies and settles along the rotation direction of the volute return plate, and the clarified clear juice flows out through an I-shaped juice outlet ring groove (2); the thickening and scraping mechanism (8) is driven to rotate by a reduction motor (5), and the settled mud juice is discharged into a mud collecting cylinder (10) in a step-by-step concentrated and squeezed manner, and flows out through a mud juice outlet.

[0027] Figure 1 It is a front view of the spiral type sedimentation system of the present invention, Figure 2 for Figure 1 A top view of the embodiment of the present invention. First, the sugarcane juice is heated by the heater and then enters the negative pressure steam diffuser (3). After the sugarcane juice has been diffused, it enters the damper (6) in the sedimentation tank. Before entering the damper (6), a flocculant should be added to the outlet pipe of the negative pressure steam diffuser (3). Driven by the sugarcane juice, the flocculant is mixed and reacted in the pipe before entering the damper (6). The damper (6) is a hollow cylindrical structure with a sealed bottom and a perforated plate in the middle. The aperture is 30 to 60 mm. The number of holes should ensure that the flow area is larger than the actual flow area required by the amount of juice, and is generally more than 3 times as much. The sugarcane juice overflows the perforated plate, so that the impact speed of the sugarcane juice is slowed down. An outward umbrella-shaped lip is arranged on the upper edge of the damper (6). The angle of the lip is about 30° to 70°, and the length of the lip is not less than 150 mm. The size of the angle is related to the lip length and the inner diameter of the volute plate, ensuring that the outflowing sugarcane juice reaches the middle section of the volute plate wall through the skirt plate at gravity speed, which helps to reduce the liquid flow impact in the initial stage of the settler.

[0028] Figure 2 is a top view of the spiral type sedimentation system of the present invention, Figure 3The top view of the volute return plate (4) is shown. The diameter, number of turns and plate spacing of the volute return plate (4) are related to the processing capacity of the settler. The damper (6) is welded to the volute return plate through a connecting piece to ensure that it is fixed at the center of the volute return plate (4). The damper (6) is connected to the starting point of the volute return plate (4) with a plate, which is conducive to the logarithmic spiral sedimentation of the overflowed sugarcane juice according to the guidance of the volute return plate. The connecting pieces in the other three directions can be perforated plates or connecting rods to facilitate the circulation of sugarcane juice. The volute return plate (4) is installed on the bottom bracket (7), and the bracket beam is welded to the tank body. The bracket beam is fixed in two layers, upper and lower, and is respectively placed on the upper and lower sides of the volute return plate (4). The top of the settler needs to use a conical top cover plate, and an observation port and a steam diffuser are reserved on the cover plate. The observation port is conducive to checking the clarification situation, and the setting of the steam diffuser is conducive to the secondary discharge of excess steam in the settler.

[0029] Figure 4 This is a front view of the step-by-step thickening and scraping mud mechanism (8) of the present invention. Figure 5 for Figure 4 The scraper device of the settler adopts a volute scraper. The center of the scraper's rotating shaft passes through the damper (6). The bottom of the shaft is supported in the bearing seat of the mud collecting barrel (10). The scraper height H is determined by the thickness h of the settled mud layer and is inversely proportional to the rotation speed of the scraper mechanism. The general value is H = 50-100 mm. The inner diameter of the scraper device is slightly larger than the diameter of the mud collecting barrel. Figure 4 From the main view, it can be seen that the scraper is in the shape of an inverted truncated cone, and the angle of its cone bottom is equal to that of the settler, generally 8° to 25°. The scraper is connected to the scraper shaft with a connecting rod, and each connecting rod and the scraper shaft form a triangular structure, which is conducive to enhancing its rigidity and the stability of the entire scraper. The end of the outermost scraper needs to be welded with an inclined scraper, which is 30mm away from the pool wall to facilitate the outermost layer of mud juice to be directed into the outer ring of the scraper for slow concentration. When the scraper shaft rotates slowly, the mud juice on the outer ring slowly squeezes into the inner ring along the rotation of the scraper. After one rotation, the mud juice moves a distance to the center of the settler, which has little static disturbance to the pool body.

[0030] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A spiral sedimentation system, comprising a sedimentation vessel body (1), a damper (6), a negative pressure diffuser (3), a spiral return plate (4), a step-by-step thickening and scraping mechanism (8), a mud collecting tube (10) and a shaped The juice outlet ring groove (2) is characterized by: The heated sugarcane juice passes through a negative pressure steam diffuser (3), and after being mixed with a flocculant, flows tangentially into the bottom of a damper (6), which is fixed at the center of a volute return plate (4), which is placed on a bottom bracket (7); the sugarcane juice overflows the damper orifice plate (11), flows along its umbrella-shaped edge into the volute return plate (4), and the sugarcane juice gradually clarifies and settles along the rotation direction of the volute return plate, and the clarified juice flows out through an I-shaped juice outlet ring groove (2); a thickening and scraping mechanism (8) is driven to rotate by a reduction motor (5), and the settled mud juice is discharged into a mud collecting cylinder (10) in a step-by-step concentrated and squeezed manner, and flows out through a mud juice outlet.

2. A spiral sedimentation system according to claim 1, characterized in that: The volute-type reflux plate (4) adopts a logarithmic spiral structure, and the sugarcane juice overflows from the upper edge of the damper (6) and flows into the middle of the volute-type reflux plate (4).

3. A spiral sedimentation system according to claim 1, characterized in that: The blades of the step-by-step thickening and scraping mechanism (8) adopt a logarithmic spiral structure.

4. The spiral sedimentation system according to claim 1, characterized in that: One to two bottom sweeping blades (9) are suspended between the spiral blades of the step-by-step thickening and scraping mechanism (8).

5. The spiral sedimentation system according to claim 1, characterized in that: The heated sugarcane juice enters the negative pressure steam diffuser box (3) in a tangential direction, and the negative pressure steam diffuser box has a structure of a box body with unequal diameters.

6. The spiral sedimentation system according to claim 1, characterized in that: The sugarcane juice enters the retarder (6) tangentially through the pipeline, and a deceleration orifice plate (11) is built in. After the sugarcane juice is decelerated, it gradually overflows the upper edge of the retarder, and the edge is in an umbrella-shaped structure.

7. The spiral sedimentation system according to claim 1, characterized in that: An I-shaped juice outlet ring groove (2) is arranged on the upper inner side of the pool wall of the settler cylinder (1), and a juice outlet is opened on the pool wall to connect with an external clear juice collection box and a pipeline outlet.

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