Stepped multi-stage centrifugal dehydrator

Abstract

An upper mounting opening and a lower mounting opening are formed in a box body, and a multi-stage screen and a supporting seat are arranged at the upper mounting opening; the multi-stage screen is of a stepped structure formed by a plurality of screen sections; a discharging opening of the feeding conveying device hermetically penetrates through the lower mounting opening and then hermetically communicates with a first through hole in the bottom of the multi-stage screen; the top of a main shaft driven by a motor hermetically penetrates through a second through hole in the bottom of the supporting seat and then is supported by an upper supporting bearing seat; a rotor is fixedly arranged on the main shaft, and the rotor is of a step-shaped structure formed by a plurality of rotor sections; discs are arranged at the bottom end of each rotor section and the upper end of the rotor; a plurality of discharging blades are arranged on the rotor section on the highest layer of the rotor, a plurality of conveying blades are arranged on the other rotor sections, and an annular cavity and a discharging pipe are arranged at the position, where the rotor section on the highest layer of the rotor is located, of the supporting seat. The structure has the advantages of low rotating speed, low energy consumption, long service life of the motor, good dehydration effect and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of waste plastic recycling, and particularly relates to a stepped multi-stage centrifugal dehydrator. Background Art

[0002] When hard materials such as waste plastic bottles and waste plastic shells are processed from waste plastics into usable plastic fragments, they need to go through multiple processes such as sorting, crushing, cleaning, dehydration, air separation, and finished product bagging. Among the above processes, dehydration is a very important process. If the plastic fragments finally entering the finished product bagging process contain too much moisture, it will affect the effect of their recycling. Therefore, it is crucial to adopt an effective dehydration method.

[0003] There are three main dehydration methods: hot air drying method, vacuum drying method, and centrifugal dehydration method. Among them, the hot air drying method evaporates the moisture in the plastic fragments through hot air. This method needs to pay attention to controlling the temperature and wind speed to avoid the plastic fragments being deformed or melted by heat. The vacuum drying method is to reduce the boiling point of water by reducing the environmental air pressure in a vacuum environment, thereby accelerating the evaporation of moisture. This method has a high equipment investment cost. The centrifugal dehydration method uses the centrifugal force generated by high-speed rotation to throw out the moisture in the plastic fragments. This method is applicable to most plastic types. Compared with the previous two methods, the centrifugal dehydration method is more commonly used in the field of waste plastic recycling.

[0004] The centrifugal dehydration method mainly relies on a centrifugal dehydrator. At present, there are mainly two methods for centrifugally dehydrating plastic fragments using a centrifugal dehydrator: One method is to equip multiple centrifugal dehydrators with different rotation speeds, and arrange the washed plastic fragments to enter each centrifugal dehydrator in the order of increasing rotation speed of the centrifugal dehydrator from low to high. Using this method requires equipping multiple centrifugal dehydrators. First, the equipment investment cost increases, and the energy consumption also increases accordingly. Second, it occupies a large space, and the required site also increases accordingly. In addition, the feeding and discharging methods of plastic fragments between each centrifugal dehydrator need to be considered, and the operation is also relatively cumbersome.

[0005] Another method is to equip a centrifugal dehydrator with a large capacity and high rotation speed, usually about 1600 r / min. The washed plastic fragments directly enter the high-speed centrifugal dehydrator for dehydration. Using this method, first, at the moment when the centrifugal dehydrator starts, since the linear velocity instantaneously increases from 0 to the maximum value, the resistance will increase when the centrifugal dehydrator starts and drives the water-containing plastic fragments to rotate. This will inevitably increase the energy consumption of the motor of the centrifugal dehydrator. In addition, the instantaneous increase in energy consumption will also reduce the service life of the motor. Second, the problem of plastic fragments being broken will occur at high rotation speeds, resulting in a large amount of powder generated during the dehydration process. This will not only affect the recovery rate but also affect the dehydration efficiency. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a stepped multi-stage centrifugal dehydrator that can ensure the centrifugal dehydration efficiency while reducing the rotational speed, and only one such centrifugal dehydrator needs to be equipped when it is used.

[0007] In a waste plastic recycling production line, in order to ensure the centrifugal dehydration efficiency of the washed plastic fragments, one way is to equip multiple centrifugal dehydrators with different rotational speeds to ensure it. This way has defects such as high equipment investment cost, high energy consumption, and large occupied space. Another way is to equip a centrifugal dehydrator with a large capacity and high rotational speed. This way has problems such as the linear velocity instantly increasing from 0 to the maximum value and relatively high rotational speed, resulting in defects such as high energy consumption, short service life of the motor, and more powder generation, which affects the recovery rate and dehydration efficiency. In view of this situation, this solution adopts the method of reducing the rotational speed and gradually increasing the linear velocity to reduce the resistance, achieve the purpose of reducing energy consumption, extending the service life of the motor, and reducing the loss of plastic fragments. The stepped multi-stage centrifugal dehydrator described in this solution is used to dehydrate the washed plastic fragments, and the water content in the dehydrated plastic fragments is about five-thousandths.

[0008] The technical solution adopted by the present invention is as follows: The described stepped multi-stage centrifugal dehydrator includes: a box body, an upper installation port communicating with the cavity of the box body is arranged at the top of the box body, and a multi-stage screen is arranged at the upper installation port. The upper end of the multi-stage screen is fixed to the top of the box body, and the multi-stage screen passes through the upper installation port downward and hangs in the cavity of the box body; the multi-stage screen is sequentially connected by several screen sections from bottom to top in sequence. The outer contour shapes of each screen section are similar, and the variation rule of the outer contour dimensions of each screen section is gradually increasing from bottom to top, so that the multi-stage screen forms a multi-level stepped structure; among them, the multi-stage screen can be an integrally formed structure, or can be formed by connecting multiple screen sections through welding or other fixed connection methods.

[0009] A support seat is arranged at the upper installation port. The upper part of the support seat is fixed to the top of the box body, and the support seat extends downward into the inner cavity of the multi-stage screen. A hollow first area is formed between the support seat and the multi-stage screen. A hollow second area is formed between the outer periphery of the multi-stage screen and the inner cavity wall of the box body. The first area and the second area are communicated through each screen hole on the multi-stage screen; A lower installation port is arranged at the bottom of the box body. A first through hole is arranged at the bottom of the multi-stage screen, and the upper installation port, the lower installation port, and the first through hole are coaxial; the discharge port of the feed conveying device is hermetically passed through the lower installation port and hermetically communicated with the first through hole; A first drain port communicating with the second area is arranged at the bottom of the box body; A second through hole is provided at the bottom of the support base. The top of the main shaft disposed in the first region is hermetically passed through the second through hole and is supported by an upper support bearing seat fixed to the support base. The main shaft is driven by a motor. A rotor is fixedly provided on the main shaft at the first region. The outer contour of the rotor is sequentially connected by several rotor segments from bottom to top. The outer contour shapes of each rotor segment are similar, and the variation law of the outer contour dimensions of each rotor segment is gradually increasing from bottom to top, so that the rotor forms a multi-level stepped structure. Discs are provided at the bottom end of each rotor segment and at the upper end of the rotor. The number of levels of the rotor is one more than the number of levels of the multi-stage screen. The highest-level rotor segment on the rotor is higher than the upper feed port. A plurality of discharge blades are fixedly provided at equal circumferential intervals on the highest-level rotor segment of the rotor. After the top of the support base passes over the highest-level rotor segment of the rotor, it turns outward and is fixedly connected to the top of the box body to form an annular cavity for accommodating the highest-level rotor segment of the rotor. A discharge pipe communicating with the annular cavity is provided on the support base. The discharge pipe is arranged in the tangential direction of the annular cavity, and the position of the discharge pipe is such that the material entering the annular cavity during the rotation of the rotor can be thrown into the discharge pipe during the rotation of each discharge blade. Except for the highest-level rotor segment on the rotor, the remaining rotor segments correspond to and match each screen segment of the multi-stage screen one by one to form an annular conveying chamber. Each layer of the conveying chamber is arranged in a stepped manner, and each layer of the conveying chamber is sequentially communicated. The conveying chamber at the lowermost layer is communicated with the discharge port of the feed conveying device, and the conveying chamber at the uppermost layer is communicated with the annular cavity. A plurality of conveying blades are fixedly provided at equal circumferential intervals on the remaining rotor segments except for the highest-level rotor segment on the rotor. The inclination directions of the conveying blades are such that the material in the corresponding conveying chamber can be driven upward by each conveying blade during the rotation of the rotor.

[0010] There are various structural forms of the feed conveying devices seen on the market. Considering factors such as the overall structure, energy consumption, and the object being plastic fragments, etc., in this solution, the feed conveying device and the main shaft are directly connected by a motor. Specifically: The structure of the feed conveying device is that a vertical pushing cylinder is hermetically and fixedly inserted into the lower installation opening, and the top of the vertical pushing cylinder is hermetically and fixedly connected to the first through hole. The open top of the vertical pushing cylinder is the discharge port of the feed conveying device, and the bottom end of the vertical pushing cylinder is hermetically sealed by a bottom sealing plate. A third through hole is provided on the bottom sealing plate. The bottom of the conveying screw disposed in the vertical pushing cylinder is hermetically passed through the third through hole and is supported by a lower support bearing seat fixed to the bottom sealing plate. The conveying screw is coaxial with the main shaft, and the top of the conveying screw is fixedly connected to the bottom of the main shaft, or the conveying screw and the main shaft are of an integral structure. A side feed port communicating with the inner cavity of the vertical material pushing cylinder is formed on the outer side wall of the lower section of the vertical material pushing cylinder, and the output end of the screw conveyor is hermetically connected to the side feed port.

[0011] Furthermore, for a stepped multi-stage centrifugal dehydrator as described above, the conveying direction of the pushing screw in the screw conveyor is perpendicular to the conveying direction of the conveying screw, and the axis of the pushing screw and the axis of the conveying screw are in the same plane. A second drain port communicating with the inner cavity of the barrel is provided at the bottom of the barrel of the screw conveyor. A filter screen is installed at the second drain port, and a filter water tank is hermetically connected to the second drain port. A filter water tank drain port is provided on the filter water tank, and a second valve is installed at the filter water tank drain port. A drain tank is hermetically connected to the first drain port. A drain tank drain port is provided on the drain tank, and a first valve is installed at the drain tank drain port. The outlets of the first valve and the second valve can be respectively connected to a drain pipe. The two drain pipes can drain separately, or can be collected and discharged to a designated area uniformly, for example, after subsequent water treatment and then recycled.

[0012] Furthermore, for a stepped multi-stage centrifugal dehydrator as described above, a support cylinder is fixedly provided on the bottom sealing plate, and the lower support bearing seat is fixed to the bottom of the support cylinder. A plurality of through holes are circumferentially spaced and formed on the barrel wall of the support cylinder. The purpose of setting the support cylinder is, firstly, to keep the lower support bearing seat away, reducing the risk of the bearing in the lower support bearing seat being contaminated by water and impurities. Secondly, when the sealing method between the conveying screw in the vertical material pushing cylinder and the third through hole preferably uses asbestos packing for sealing, a pressing structure is used to press the asbestos packing when using asbestos packing for sealing. The setting of the support cylinder with through holes can facilitate the operator to reach the pressing structure through the through holes to adjust the pressing structure. In addition, the setting of the through holes can also reduce the consumables and weight of the support cylinder.

[0013] Furthermore, for a stepped multi-stage centrifugal dehydrator as described above, the inclination angle α of the conveying blade is 12°.

[0014] Furthermore, for a stepped multi-stage centrifugal dehydrator as described above, the outer end of the bottom of the conveying blade extends downward to form a bottom convex plate integral with the conveying blade. The bottom convex plate extends downward beyond the disc at the bottom end of the corresponding rotor section. The inner side edge of the bottom convex plate is an inclined edge that gradually inclines outward from top to bottom, so that the bottom convex plate forms a trapezoidal structure.

[0015] Furthermore, in the aforementioned stepped multi-stage centrifugal dehydrator, the bearings in the upper support bearing seat are preferably a pair of angular contact ball bearings, because angular contact ball bearings have many significant advantages, including high-speed performance, high load bearing, compact design, good self-aligning performance, long life and easy maintenance, etc. During the dehydration process of the centrifugal dehydrator, one is that the cleaned plastic fragments will inevitably carry some impurities, and the other is that in the process of centrifugal dehydration, since the dehydration object is plastic fragments, powder will exist more or less. Therefore, during the use of the centrifugal dehydrator, these impurities and powder will adhere to the multi-stage screen. As the use time of the centrifugal dehydrator increases, the adhered impurities and powder will increase, and eventually block the screen holes on the multi-stage screen, affecting the dehydration efficiency. Therefore, this solution is provided with a screen cleaning device for cleaning the multi-stage screen in the second area; The structure of the screen cleaning device is as follows: a main mounting seat is suspended in the second area, and the main mounting seat is driven to rotate by a driving device; a plurality of lower mounting seats are fixedly arranged at the bottom of the main mounting seat, and each lower mounting seat is evenly spaced circumferentially around the periphery of the multi-stage screen; an internal silicone plate group for cleaning the multi-stage screen is installed on the inner side of each lower mounting seat, and an external silicone plate group for cleaning the side wall of the inner cavity of the box is installed on the outer side of each lower mounting seat.

[0016] Furthermore, in the aforementioned stepped multi-stage centrifugal dehydrator, the inner side of the lower mounting seat is composed of multiple sections of vertical inner side, and each section of the vertical inner side is gradually approached inward from top to bottom to form a stepped shape corresponding to the outer contour of the multi-stage screen; An internal silicone plate is installed on each vertical inner side edge, and all the internal silicone plates on the lower mounting seat form an internal silicone plate group.

[0017] Furthermore, in the aforementioned stepped multi-stage centrifugal dehydrator, the structure of the driving device is as follows: a rotating toothed disc is fixedly arranged on the top of the main mounting seat, and a plurality of supporting gears are supported on the top of the inner cavity of the box body, each supporting gear is meshed with the rotating gear, and each supporting gear is evenly spaced circumferentially around the rotating gear, and one of the supporting gears is driven to rotate by a reduction motor; an upper shoulder is arranged at the upper end of each supporting gear, and a lower shoulder is arranged at the lower end of each supporting gear, and the upper shoulder and the lower shoulder on each supporting gear jointly form axial positioning of the rotating toothed disc.

[0018] The beneficial effects of the present invention are as follows: ① For the stepped multi-stage centrifugal dehydrator of the present invention, the rotational speed can be reduced to 960 - 1000 r / min. The reduction in rotational speed also reduces the loss rate of plastic fragments and energy consumption. While reducing the rotational speed of the stepped multi-stage centrifugal dehydrator, the method of gradually increasing the linear velocity is adopted, which can not only reduce resistance, lower energy consumption, protect the motor, and extend the service life of the motor, but also ensure the dehydration efficiency after centrifugal dehydration. The moisture content in the plastic fragments after dehydration is about five-thousandths, and the dehydration effect is good. ② The main shaft and the conveying screw are directly connected to the motor, sharing the same motor. First, it can simplify the overall structure, and second, it can further reduce energy consumption. ③ The setting of the screen cleaning device can scrape off the attachments on the multi-stage screen and the side wall of the inner cavity of the box body to ensure that the screen holes on the multi-stage screen are always unobstructed, thereby ensuring the dehydration efficiency of the centrifugal dehydrator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic internal structure diagram of a stepped multi-stage centrifugal dehydrator according to the present invention.

[0020] Figure 2 is Figure 1 a partial enlarged structure diagram.

[0021] Figure 3 is Figure 1 a structure diagram in the sectional view direction of A - A in

[0022] Figure 4 is Figure 1 a structure diagram of the main shaft, the conveying screw, and the rotor without sectioning in

[0023] Figure 5 is Figure 4 a partial enlarged structure diagram of part B in

[0024] Figure 6 is Figure 1 a structure diagram of the multi-stage screen in

[0025] Figure 7 is Figure 6 a structure diagram in the top view direction.

[0026] Figure 8 is a schematic internal structure diagram of a stepped multi-stage centrifugal dehydrator with a screen cleaning device according to the present invention.

[0027] Figure 9 is Figure 8 a partial enlarged structure diagram of part C in

[0028] Figure 10 is Figure 8 a structure diagram in the top view direction.

[0029] Wherein: 1. Box body; 11. Upper mounting opening; 12. Lower mounting opening; 13. Drainage tank; 14. First valve; 2. Multi-stage screen; 21. Screen section; 22. Connecting plate; 23. First through hole; 3. Support seat; 31. Second through hole; 32. Annular cavity; 4. Main shaft; 41. Upper support bearing seat; 42. Motor; 5. Rotor; 51. Rotor section; 52. Disc; 53. Highest-level rotor section; 6. Conveyor blade; 61. Bottom convex plate; 62. Inclined edge; 63. Discharge blade; 7. Support cylinder; 71. Through hole; 72. Lower support bearing seat; 81. Vertical pusher cylinder; 82. Conveyor screw; 83. Bottom sealing plate; 84. Side feed port; 85. Screw conveyor; 86. Pusher screw; 87. Filter water tank; 88. Second valve; 9. Main mounting seat; 91. Lower mounting seat; 92. Inner silica gel plate; 93. Long strip silica gel plate; 94. Rotating tooth disc; 95. Support gear; 950. Gear shaft; 951. Upper shoulder; 952. Lower shoulder; 100. Second region; 200. Conveying chamber; 201. Lowest-level conveying chamber; 202. Highest-level conveying chamber; 300. First region. Detailed implementation mode

[0030] The technical solution of the present invention will be further described in detail below with reference to the drawings and preferred embodiments.

[0031] In the following, example embodiments will be described more fully with reference to the drawings. However, the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0032] In the case of no conflict, the various embodiments of the present disclosure and the features in the embodiments may be combined with each other. Embodiment 1

[0033] As Figure 1 、 Figure 6 and Figure 7 shown, a stepped multi-stage centrifugal dehydrator described in this embodiment includes: a box body 1. An upper mounting opening 11 communicating with the cavity of the box body 1 is provided at the top of the box body 1. A multi-stage screen 2 is provided at the upper mounting opening 11. The upper end of the multi-stage screen 2 is fixed to the top of the box body 1. The multi-stage screen 2 passes downward through the upper mounting opening 11 and hangs in the cavity of the box body 1. The multi-stage screen 2 is sequentially composed of several screen sections 21 from bottom to top. The outer contour shapes of the screen sections 21 are similar, and the variation law of the outer contour dimensions of the screen sections 21 is gradually increasing from bottom to top, so that the multi-stage screen 2 forms a multi-level stepped structure; a connecting plate 22 for fixedly connecting with the box body 1 is provided at the top of the multi-stage screen 2.

[0034] Among them, the multi-stage screen 2 can be an integrally formed structure, such as integrally stamping and forming, or can be composed of multiple screen segments 21 connected by welding or other fixed connection methods.

[0035] In addition, for such a common centrifugal dehydrator, compared with a household centrifugal dehydrator, it is much larger. When a certain or some areas of the multi-stage screen 2 are deformed, damaged, etc. and need to be replaced, the multi-stage screen 2 needs to be replaced as a whole. At this time, the components that hinder the removal of the multi-stage screen 2 need to be removed one by one, and then the multi-stage screen 2 can be disassembled. The operation is very cumbersome and time-consuming and laborious. To solve this problem, in this solution, the multi-stage screen is designed as a skeleton structure, and multiple segmented screens are spliced on the skeleton structure. At this time, only the corresponding segmented screen needs to be replaced, and there is no need to remove multiple components anymore.

[0036] As Figure 7 shown, the outer contour of each screen segment 21 preferably selects a regular polygon structure, such as a regular dodecagon.

[0037] As Figure 1 shown, a support seat 3 is provided at the upper mounting port 11. The upper part of the support seat 3 is fixed to the top of the box body 1. The support seat 3 extends downward into the inner cavity of the multi-stage screen 2. A hollow first area 300 is formed between the support seat 3 and the multi-stage screen 2. A hollow second area 100 is formed between the outer periphery of the multi-stage screen 2 and the inner cavity wall of the box body 1. The first area 300 and the second area 100 are communicated through each screen hole on the multi-stage screen 2. At this time, the first area 300 and the second area 100 are in a sealed space.

[0038] As Figure 1 and Figure 6 shown, a lower mounting port 12 is provided at the bottom of the box body. A first through hole 23 is provided at the bottom of the multi-stage screen 2, and the upper mounting port 11, the lower mounting port 12, and the first through hole 23 are coaxial; the discharge port of the feed conveying device passes through the lower mounting port 12 in a sealed manner and is in sealed communication with the first through hole 23. At this time, the discharge port of the feed conveying device is communicated with the first area 300. In this embodiment, the feed conveying device used only needs to be able to send the washed plastic fragments into the first area 300.

[0039] A first drain port communicating with the second area 100 is provided at the bottom of the box body 1. The first drain port can directly lead out the water in the second area 100 through a pipeline connection, or a drain tank 13 is hermetically connected to the first drain port, as Figure 1As shown, a drain opening is provided on the drain tank 13, and a first valve 14 is installed at the drain opening of the drain tank. The water in the second region 100 first enters the drain tank 13 through the first drain opening. When the first valve 14 is opened, the water in the drain tank 13 is discharged through the first valve 14.

[0040] As Figure 1 and Figure 2 As shown, a second through hole 31 is provided at the bottom of the support base 3. The top of the main shaft 4 disposed in the first region 300 is hermetically passed through the second through hole 31 and supported by an upper support bearing seat 41 fixed to the support base 3. The main shaft 4 is driven by a motor 42.

[0041] The bearings in the upper support bearing seat 41 are preferably a pair of angular contact ball bearings, which is considered that angular contact ball bearings have several significant advantages, including high-speed performance, high load-bearing capacity, compact design, good self-aligning performance, long service life and easy maintenance, etc.

[0042] As Figure 1 and Figure 2 As shown, a rotor 5 is fixedly provided on the main shaft 4 at the first region 300. The outer contour of the rotor 5 is sequentially connected by several rotor segments 51 from bottom to top. The outer contour shapes of each rotor segment 51 are similar, and the change rule of the outer contour dimensions of each rotor segment 51 is gradually increasing from bottom to top, so that the rotor 5 forms a multi-level stepped structure; discs 52 are provided at the bottom end of each rotor segment 51 and at the upper end of the rotor 5.

[0043] Considering the installation of the upper support bearing seat 41, the installation of the motor 42 and the shape of the rotor 5, the support base 3 is also set in a stepped shape.

[0044] As Figure 1 , Figure 2 and Figure 3 As shown, the number of levels of the rotor 5 is one more than the number of levels of the multi-stage screen 2. The highest-level rotor segment of the rotor 5 is higher than the upper feed port 11. A plurality of discharge blades 63 are fixedly provided at equal circumferential intervals on the highest-level rotor segment 53 of the rotor 5. The top of the support base 3 is turned outwards after passing over the highest-level rotor segment 53 of the rotor 5 and is fixedly connected to the top of the box body 1 to form an annular cavity 32 for accommodating the highest-level rotor segment of the rotor 5. A discharge pipe 33 communicating with the annular cavity 32 is provided on the support base 3. The discharge pipe 33 is provided in the tangential direction of the annular cavity 32, and the position of the discharge pipe 33 is such that the material entering the annular cavity 32 when the rotor 5 rotates can be thrown into the discharge pipe 33 during the rotation of each discharge blade 63.

[0045] Except for the rotor segment 53 at the highest level on the rotor 5, the remaining rotor segments are in one-to-one correspondence and matching with the respective sieve mesh segments 21 on the multi-stage sieve mesh 2 to form an annular conveying chamber 200. The conveying chambers 200 of each layer are arranged in a stepped manner, and the conveying chambers 200 of each layer are sequentially connected. The conveying chamber 201 at the lowermost layer is connected to the discharge port of the feed conveying device, and the conveying chamber 202 at the uppermost layer is connected to the annular cavity 32.

[0046] As Figure 2 and Figure 4 shown, on the remaining rotor segments except for the rotor segment 53 at the highest level on the rotor 5, a number of conveying vanes 6 are fixedly arranged at equal intervals in the circumferential direction. The inclination direction of each conveying vane 6 enables the materials in the corresponding conveying chamber 200 to be driven upward by each conveying vane 6 when the rotor 5 rotates.

[0047] As Figure 5 shown, in this embodiment, the inclination angle α of the conveying vane 6 is preferably selected as 12°.

[0048] A more preferred solution is that a bottom convex plate 61 integrated with the conveying vane 6 extends downward at the outer end of the bottom of the conveying vane 6. As Figure 2 and Figure 4 shown, the bottom convex plate 61 extends downward beyond the disk 52 at the bottom end of the corresponding rotor segment 51; the inner side edge of the bottom convex plate 61 is an inclined edge 62 that gradually inclines outward from top to bottom, so that the bottom convex plate 61 forms a trapezoidal structure.

[0049] Here, it is illustrated by taking the multi-stage sieve mesh 2 having five sieve mesh segments 21 as an example. At this time, the rotor 5 has five rotor segments 51. Taking one of the centrifugal dehydrators as an example, the rotational speed is set to 1000 r / min. At this time, the linear velocities of each level from bottom to top are: 25.6 m / s, 33.3 m / s, 40.3 m / s, 55.0 m / s, 62.3 m / s, and the linear velocity increases step by step. The washed plastic fragments are sent into the conveying chamber 201 at the lowermost layer through the feed conveying device, and then are centrifugally dehydrated by the corresponding conveying vanes 6 and enter the conveying chamber 200 of the upper layer step by step upward. Finally, they enter the annular cavity 32 from the conveying chamber 202 at the uppermost layer, and then are thrown into the discharge pipe 33 through the respective discharge vanes 63 for discharging.

[0050] The stepped multi-stage centrifugal dehydrator of the present invention can reduce the rotational speed to 960 - 1000 r / min. The reduction of the rotational speed also reduces the loss rate of plastic fragments and energy consumption; while reducing the rotational speed of the stepped multi-stage centrifugal dehydrator, the method of gradually increasing the linear velocity is adopted, which can not only reduce the resistance, reduce the energy consumption, protect the motor, and extend the service life of the motor, but also ensure the dehydration efficiency after centrifugal dehydration. The moisture in the plastic fragments after dehydration is about five per thousand, and the dehydration effect is good. Example Two

[0051] As Figure 1 、 Figure 6 and Figure 7 shown, a stepped multi-stage centrifugal dehydrator described in this embodiment includes: a box body 1. An upper mounting opening 11 communicating with the cavity of the box body 1 is provided at the top of the box body 1. A multi-stage screen 2 is provided at the upper mounting opening 11. The upper end of the multi-stage screen 2 is fixed to the top of the box body 1, and the multi-stage screen 2 passes downward through the upper mounting opening 11 and then hangs in the cavity of the box body 1. The multi-stage screen 2 is sequentially connected by a plurality of screen sections 21 from bottom to top. The outer contour shapes of the respective screen sections 21 are similar, and the variation rule of the outer contour dimensions of the respective screen sections 21 is that they gradually increase from bottom to top, so that the multi-stage screen 2 forms a multi-level stepped structure; a connecting plate 22 for fixedly connecting with the box body 1 is provided at the top end of the multi-stage screen 2.

[0052] As Figure 1 shown, a support seat 3 is provided at the upper mounting opening 11. The upper part of the support seat 3 is fixed to the top of the box body 1, and the support seat 3 extends downward into the inner cavity of the multi-stage screen 2. A hollow first area 300 is formed between the support seat 3 and the multi-stage screen 2. A hollow second area 100 is formed between the periphery of the multi-stage screen 2 and the inner cavity wall of the box body 1. The first area 300 and the second area 100 are communicated through the respective screen holes on the multi-stage screen 2. At this time, the first area 300 and the second area 100 are in a sealed space.

[0053] As Figure 1 and Figure 6 shown, a lower mounting opening 12 is provided at the bottom of the box body. A first through hole 23 is provided at the bottom of the multi-stage screen 2, and the upper mounting opening 11, the lower mounting opening 12, and the first through hole 23 are coaxial; the discharge port of the feed conveying device is hermetically passed through the lower mounting opening 12 and hermetically communicated with the first through hole 23. At this time, the discharge port of the feed conveying device is communicated with the first area 300.

[0054] A first drain port communicating with the second area 100 is provided at the bottom of the box body 1. The first drain port can directly lead out the water in the second area 100 through a pipeline connection, or a drain box 13 is hermetically connected at the first drain port. As Figure 1 shown, a drain box drain port is provided on the drain box 13, and a first valve 14 is installed at the drain box drain port. The water in the second area 100 first enters the drain box 13 through the first drain port. When the first valve 14 is opened, the water in the drain box 13 is discharged through the first valve 14.

[0055] As Figure 1 andFigure 2 As shown, a second through-hole 31 is provided at the bottom of the support base 3. The top of the main shaft 4 disposed in the first region 300 is hermetically passed through the second through-hole 31 and supported by an upper support bearing seat 41 fixed to the support base 3. The main shaft 4 is driven by a motor 42.

[0056] As Figure 1 and Figure 2 shown, a rotor 5 is fixedly provided on the main shaft 4 at the first region 300. The outer contour of the rotor 5 is sequentially connected by several rotor segments 51 from bottom to top. The outer contour shapes of each rotor segment 51 are similar, and the variation rule of the outer contour dimensions of each rotor segment 51 is gradually increasing from bottom to top, so that the rotor 5 forms a multi-level stepped structure; discs 52 are provided at the bottom end of each rotor segment 51 and at the upper end of the rotor 5.

[0057] As Figure 1 , Figure 2 and Figure 3 shown, the number of levels of the rotor 5 is one more than the number of levels of the multi-stage sieve mesh 2. The highest-level rotor segment of the rotor 5 is higher than the upper feed port 11. A plurality of discharge blades 63 are fixedly provided at equal circumferential intervals on the highest-level rotor segment 53 of the rotor 5. The top of the support base 3 is turned outwards after passing over the highest-level rotor segment 53 of the rotor 5 and fixedly connected to the top of the box body 1 to form an annular cavity 32 for accommodating the highest-level rotor segment of the rotor 5. A discharge pipe 33 communicating with the annular cavity 32 is provided on the support base 3. The discharge pipe 33 is arranged in the tangential direction of the annular cavity 32, and the position of the discharge pipe 33 is such that the material entering the annular cavity 32 during the rotation of the rotor 5 can be thrown into the discharge pipe 33 during the rotation of each discharge blade 63.

[0058] Except for the highest-level rotor segment 53 of the rotor 5, the remaining rotor segments are respectively and correspondingly matched with each sieve mesh segment 21 of the multi-stage sieve mesh 2 to form an annular conveying chamber 200. Each layer of the conveying chamber 200 is arranged in a stepped manner, and each layer of the conveying chamber 200 is sequentially communicated. The lowermost conveying chamber 201 is communicated with the discharge port of the feed conveying device, and the uppermost conveying chamber 202 is communicated with the annular cavity 32.

[0059] As Figure 2 and Figure 4 shown, a plurality of conveying blades 6 are fixedly provided at equal circumferential intervals on the remaining rotor segments except for the highest-level rotor segment 53 of the rotor 5. The inclination directions of the conveying blades 6 are such that the materials in the corresponding conveying chambers 200 can be driven upwards by each conveying blade 6 during the rotation of the rotor 5.

[0060] The working process of the stepped multi-stage centrifugal dehydrator is as follows: The cleaned plastic fragments are sent into the lowest conveying chamber 201 through the feeding and conveying device, and then are centrifugally dehydrated by the corresponding conveying blades 6 and enter the upper-layer conveying chamber 200 step by step upward, and finally enter the annular cavity 32 from the uppermost conveying chamber 202, and then are thrown into the discharge pipe 33 through the respective discharge blades 63 for discharging.

[0061] At present, there are various structural forms of the feeding and conveying device seen on the market. Considering factors such as the overall structure and energy consumption, the feeding and conveying device with the following structure is designed in this solution, specifically as follows: As Figure 1 And Figure 2 As shown, the vertical pusher cylinder 81 is hermetically and fixedly inserted through the lower mounting opening 12, and the top of the vertical pusher cylinder 81 is hermetically and fixedly connected to the first through hole 23; the open top of the vertical pusher cylinder 81 is the discharge port of the feeding and conveying device, and the bottom end of the vertical pusher cylinder 81 is hermetically sealed by the bottom sealing plate 83; A third through hole is provided on the bottom sealing plate 83, and the bottom of the conveying screw 82 provided in the vertical pusher cylinder 83 is hermetically passed through the third through hole and supported by the lower support bearing seat 72 fixed on the bottom sealing plate 83; The conveying screw 82 is coaxial with the main shaft 4, and the top of the conveying screw 82 is fixedly connected to the bottom of the main shaft 4, or the conveying screw 82 and the main shaft 4 are of an integral structure.

[0062] A side feeding port 84 communicating with the inner cavity of the vertical pusher cylinder 81 is opened on the outer side wall of the lower section of the vertical pusher cylinder 81, and the output end of the screw conveyor 85 is hermetically connected to the side feeding port 84.

[0063] The conveying direction of the pusher screw 86 in the screw conveyor 85 is perpendicular to the conveying direction of the conveying screw 82, and the axis of the pusher screw 86 and the axis of the conveying screw 82 are in the same plane.

[0064] A second drain port communicating with the inner cavity of the barrel is provided at the bottom of the barrel of the screw conveyor 85. A filter screen is installed at the second drain port, and a filter water tank 87 is also hermetically connected to the second drain port. A filter water tank drain port is provided on the filter water tank 87, and a second valve 88 is installed at the filter water tank drain port.

[0065] A support cylinder 7 is fixedly arranged on the bottom sealing plate 83, and a lower support bearing seat 72 is fixed to the bottom of the support cylinder 7. A plurality of through holes 71 are provided on the cylinder wall of the support cylinder 7 at intervals along the circumferential direction. The purpose of setting the support cylinder 7 is, firstly, to keep the lower support bearing seat 72 away, reduce the risk of the bearing in the lower support bearing seat 72 being contaminated by water and impurities, and increase the service life of the bearing; secondly, the sealing method between the conveying screw 82 in the vertical pushing cylinder 81 and the third through hole is preferably to use asbestos packing for sealing. When the asbestos packing is used for sealing, a compression structure is used to compress the asbestos packing. The setting of the support cylinder 7 with the through hole 71 can facilitate the operator to reach into the compression structure through the through hole 71 to adjust the compression structure. In addition, the setting of the through hole 71 can also reduce the consumables and weight of the support cylinder 7.

[0066] In this solution, the main shaft 4 and the conveying screw 82 are directly connected by a motor, that is, the two share the same motor, which can simplify the overall structure and further reduce energy consumption. Embodiment 3

[0067] This embodiment is based on the first or second embodiment and a net cleaning device is added.

[0068] Whether it is the stepped multi-stage centrifugal dehydrator described in the present application or the centrifugal dehydrator available on the market, when used to dehydrate the cleaned plastic fragments, one is that the cleaned plastic fragments will inevitably carry some impurities, and the other is that in the process of centrifugal dehydration, since the dehydration object is plastic fragments, powder will exist more or less. Therefore, during the use of the centrifugal dehydrator, these impurities and powder will adhere to the multi-stage screen 2. As the use time of the centrifugal dehydrator increases, the adhered impurities and powder will increase, and eventually block the screen holes on the multi-stage screen 2. Therefore, this scheme is provided with a cleaning device for cleaning the multi-stage screen 2 in the second area 100.

[0069] like Figure 8 and Figure 9 As shown, in this embodiment, the structure of the screen cleaning device is as follows: a main mounting seat 9 is suspended in the second area 100, and the main mounting seat 9 is driven to rotate by a driving device; a plurality of lower mounting seats 91 are fixedly arranged at the bottom of the main mounting seat 9, and each lower mounting seat 91 is uniformly spaced circumferentially around the periphery of the multi-stage screen 2; an internal silicone plate group for cleaning the multi-stage screen 2 is installed on the inner side of each lower mounting seat 91, and an external silicone plate group for cleaning the side wall of the inner cavity of the box body 1 is installed on the outer side of each lower mounting seat 91.

[0070] Among them, the inner side of the lower mounting base 91 is composed of multiple vertical inner sides, and each section of the vertical inner side gradually approaches inward from top to bottom, forming a stepped shape corresponding to and matching the outer contour of the multi-stage screen 2; an internal silica gel plate 92 is installed on each section of the vertical inner side, and all the internal silica gel plates 92 on the lower mounting base 91 form an internal silica gel plate group.

[0071] Among them, the outer side of the lower mounting base 91 is a straight edge from top to bottom, so the external silica gel plate group can be a whole long strip-shaped silica gel plate 93.

[0072] The driving device has various structural forms. Here, considering factors such as installation space, the driving device is designed as follows. For example Figure 8 、 Figure 9 and Figure 10 As shown, the structure of the driving device is: a rotating gear disk 94 is fixedly arranged on the top of the main mounting base 9, and a plurality of support gears 95 are supported and arranged on the top of the inner cavity of the box body 1. The gear shafts 950 of the support gears 95 are fixed to the top of the box body 1. Each support gear 95 meshes with the rotating gear disk 94, and each support gear 95 is circumferentially and evenly spaced around the rotating gear disk. One of the support gears 95 is driven to rotate by a reduction motor 96; an upper shoulder 951 is arranged at the upper end of each support gear 95, and a lower shoulder 952 is arranged at the lower end of each support gear 95. The upper shoulder 951 and the lower shoulder 952 on each support gear 95 jointly form an axial positioning for the rotating gear disk 94.

[0073] The setting of the screen cleaning device can scrape off the attachments on the multi-stage screen 2 and the side wall of the inner cavity of the box body 1 to ensure that the screen holes on the multi-stage screen 2 are always unobstructed, thereby ensuring the dehydration efficiency of the stepped multi-stage centrifugal dehydrator.

[0074] The above are only the preferred embodiments of the present invention, and it is not a limitation to the present invention in any other form. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. A stepped multi-stage centrifugal dehydrator, comprising: The box body is characterized in that: an upper mounting opening communicating with the cavity of the box body is arranged at the top of the box body, a multi-stage screen is arranged at the upper mounting opening, the upper end of the multi-stage screen is fixed to the top of the box body, and the multi-stage screen passes downward through the upper mounting opening and is suspended in the cavity of the box body; the multi-stage screen is composed of a plurality of screen segments connected in sequence from bottom to top, the outer contour shapes of the screen segments are similar, and the outer contour size change rule of the screen segments is gradually increased from bottom to top, so that the multi-stage screen forms a multi-level stepped structure; A support seat is provided at the upper installation opening, the upper part of the support seat is fixed to the top of the box, the support seat extends downward into the inner cavity of the multi-stage screen, a hollow first area is formed between the support seat and the multi-stage screen, a hollow second area is formed between the periphery of the multi-stage screen and the inner cavity wall of the box, and the first area and the second area are connected through the screen holes on the multi-stage screen; A lower mounting opening is provided at the bottom of the box body, a first through hole is provided at the bottom of the multi-stage screen, and the upper mounting opening, the lower mounting opening and the first through hole are coaxial; the discharge port of the feed conveying device is sealed and connected to the first through hole after passing through the lower mounting opening; A first drain port communicating with the second area is provided at the bottom of the box; A second through hole is provided at the bottom of the support seat, and the top seal of the main shaft arranged in the first area passes through the second through hole and is supported by an upper support bearing seat fixed on the support seat, and the main shaft is driven by a motor; A rotor is fixedly arranged on the main shaft in the first area, and the outer contour of the rotor is composed of a plurality of rotor segments connected in sequence from bottom to top, and the outer contour shapes of the rotor segments are similar, and the outer contour size of the rotor segments increases step by step from bottom to top, so that the rotor forms a multi-level stepped structure; a disc is arranged at the bottom end of each rotor segment and the upper end of the rotor; The number of levels of the rotor is one more than the number of levels of the multi-stage screen, the rotor segment of the highest level on the rotor is higher than the upper feed port, a plurality of discharge blades are fixedly arranged at even intervals along the circumferential direction on the rotor segment of the highest level on the rotor, the top of the support seat passes over the rotor segment of the highest level on the rotor, flips outwards and is fixedly connected to the top of the box body, forming an annular cavity for accommodating the rotor segment of the highest level on the rotor, a discharge pipe connected to the annular cavity is arranged on the support seat, the discharge pipe is arranged in the tangential direction of the annular cavity, and the position of the discharge pipe allows the material entering the annular cavity when the rotor rotates to be thrown into the discharge pipe during the rotation of each discharge blade; Except for the rotor segments on the highest layer of the rotor, the remaining rotor segments correspond to each segment of the screen on the multi-stage screen one by one to form an annular conveying chamber. The conveying chambers on each layer are arranged in a stepped manner, and the conveying chambers on each layer are connected in sequence. The conveying chamber on the lowest layer is connected to the discharge port of the feed conveying device, and the conveying chamber on the uppermost layer is connected to the annular cavity. A number of conveying blades are fixedly arranged at even intervals along the circumference on the rotor sections except the highest rotor section on the rotor. The inclination direction of each conveying blade ensures that the materials in the corresponding conveying chamber can be driven by each conveying blade to be conveyed upward when the rotor rotates.

2. A stepped multi-stage centrifugal dehydrator according to claim 1, characterized in that: The structure of the feed conveying device is as follows: the vertical push barrel is sealed and fixedly inserted into the lower installation opening, and the top of the vertical push barrel is sealed and fixedly connected to the first through hole; the open opening at the top of the vertical push barrel is the discharge opening of the feed conveying device, and the bottom end of the vertical push barrel is sealed and closed by the bottom sealing plate; A third through hole is provided on the bottom sealing plate, and the bottom seal of the conveying screw arranged in the vertical pushing barrel passes through the third through hole and is supported by a lower support bearing seat fixed on the bottom sealing plate; The conveying screw is coaxial with the main shaft, and the top of the conveying screw is fixedly connected to the bottom of the main shaft, or the conveying screw and the main shaft are an integrated structure; A side feed port connected with the inner cavity of the vertical pushing barrel is provided on the outer side wall of the lower section of the vertical pushing barrel, and the output end of the screw conveyor is sealed and connected with the side feed port.

3. A stepped multi-stage centrifugal dehydrator according to claim 2, characterized in that: The conveying direction of the push screw in the screw conveyor is perpendicular to the conveying direction of the conveying screw, and the axis of the push screw and the axis of the conveying screw are in the same plane; A second drain port connected to the inner cavity of the barrel is provided at the bottom of the barrel of the screw conveyor, a filter screen is installed at the second drain port, a water filter box is also sealed at the second drain port, a water filter box drain port is provided on the water filter box, and a second valve is installed at the water filter box drain port; A drainage box is sealed and connected to the first drainage outlet, a drainage box drainage outlet is arranged on the drainage box, and a first valve is installed at the drainage box drainage outlet.

4. A stepped multi-stage centrifugal dehydrator according to claim 2 or 3, characterized in that: A support cylinder is fixedly arranged on the bottom sealing plate, a lower support bearing seat is fixed to the bottom of the support cylinder, and a plurality of through holes are spaced apart along the circumferential direction on the cylinder wall of the support cylinder.

5. The stepped multi-stage centrifugal dehydrator according to claim 1, characterized in that: The inclination angle α of the conveying blade is 12°.

6. A stepped multi-stage centrifugal dehydrator according to claim 1 or 5, characterized in that: The bottom outer end of the conveying blade extends downward to form a bottom convex plate which is integral with the conveying blade, and the bottom convex plate passes downward over the disc on the bottom end of the corresponding rotor segment; the inner side edge of the bottom convex plate is an inclined edge which gradually inclines outward from top to bottom, so that the bottom convex plate forms a trapezoidal structure.

7. The stepped multi-stage centrifugal dehydrator according to claim 1, characterized in that: The bearings in the upper support bearing seat are a pair of angular contact ball bearings.

8. The stepped multi-stage centrifugal dehydrator according to claim 1, characterized in that: A screen cleaning device for cleaning the screen is provided in the second area; The structure of the screen cleaning device is as follows: a main mounting seat is suspended in the second area, and the main mounting seat is driven to rotate by a driving device; a plurality of lower mounting seats are fixedly arranged at the bottom of the main mounting seat, and each lower mounting seat is evenly spaced circumferentially around the periphery of the multi-stage screen; an internal silicone plate group for cleaning the multi-stage screen is installed on the inner side of each lower mounting seat, and an external silicone plate group for cleaning the side wall of the inner cavity of the box is installed on the outer side of each lower mounting seat.

9. A stepped multi-stage centrifugal dehydrator according to claim 8, characterized in that: The inner side of the lower mounting seat is composed of multiple sections of vertical inner side, and each section of the vertical inner side is gradually approached inward from top to bottom to form a stepped shape corresponding to the outer contour of the multi-stage screen; An internal silicone plate is installed on each vertical inner side edge, and all the internal silicone plates on the lower mounting seat form an internal silicone plate group.

10. A stepped multi-stage centrifugal dehydrator according to claim 8 or 9, characterized in that: The structure of the driving device is as follows: a rotating toothed disc is fixedly arranged on the top of the main mounting seat, and a plurality of supporting gears are supported on the top of the inner cavity of the box body, each supporting gear is meshed with the rotating gear, and each supporting gear is evenly spaced circumferentially around the rotating gear, and one of the supporting gears is driven to rotate by a reduction motor; an upper shoulder is arranged at the upper end of each supporting gear, and a lower shoulder is arranged at the lower end of each supporting gear, and the upper shoulder and the lower shoulder on each supporting gear jointly form axial positioning of the rotating toothed disc.

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