Extruder for large-diameter steel skeleton composite pipe production line

Abstract

According to the extruder for the large-diameter steel skeleton composite pipe production line, when plastic particles are conveyed into a hopper, a feeding opening is closed through an opening and closing mechanism, a negative pressure dust remover is opened, and in the process that the plastic particles are conveyed into a temporary storage bin, dust in the plastic particles can be sucked in a negative pressure mode; flowing air carrying dust enters a negative-pressure dust remover along an annular metal filter plate, an annular negative-pressure box and an annular negative-pressure pipe to be filtered, so that dust in plastic particles (the plastic particles are also raised in the process of entering a temporary storage bin) is sucked and collected under negative pressure; after dust in the temporary storage bin is subjected to negative pressure suction and collection, the feeding opening is opened through the opening and closing mechanism, and plastic particles enter the hopper; and finally, dust in the plastic particles in the temporary storage bin is sucked and collected under negative pressure in batches, the dust removal effect can be improved, and the dust in the plastic particles can be efficiently separated.

Description

Technical Field

[0001] This invention relates to the field of plastic extrusion molding equipment technology, and in particular to an extruder for a large-diameter steel-reinforced composite pipe production line. Background Technology

[0002] The large-diameter steel-reinforced composite pipe production line is mainly used to produce steel-plastic composite structure pipes. The structure includes a polyethylene inner layer, a steel skeleton middle layer, and a polyethylene outer layer. It combines the high strength of steel with the corrosion resistance of plastic and is suitable for municipal engineering, energy transmission, chemical industry and other fields, especially meeting the needs of high pressure and high flow fluid transmission.

[0003] The extruder is the core equipment in the production line, responsible for melting and plasticizing polyethylene plastic granules and extruding them to form a pipe structure with a steel wire skeleton. This directly affects the pipe's strength, uniformity, and production efficiency. However, dust particles entrained in the plastic granules are difficult to completely disperse during the melting process, easily forming local concentration gradients. This causes unstable melt flow, leading to defects such as uneven pipe wall thickness, rough inner walls, and obvious seams. Poor plasticization may result in a "toad skin" texture on the melt surface, affecting the pipe's pressure-bearing capacity. Therefore, there is an urgent need to design an extruder capable of separating dust from the plastic granules. Summary of the Invention

[0004] The purpose of this invention is to provide an extruder for a large-diameter steel-reinforced composite pipe production line, which can separate dust from plastic particles.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: an extruder for a large-diameter steel-reinforced composite pipe production line, comprising an extruder body and a hopper disposed on the extruder body, characterized in that: a feed inlet is provided at the top of the hopper, a buffer chamber is provided on the feed inlet, a first ventilation hole is arranged in a circumferential array on the periphery of the buffer chamber, and a dust removal device for performing negative pressure dust removal on the periphery of the buffer chamber is provided at the top of the hopper;

[0006] The top of the hopper is provided with an opening and closing mechanism to open or close the feed inlet;

[0007] The dust removal device includes an annular negative pressure box fitted around the periphery of the buffer bin, an annular metal filter plate disposed in the inner ring of the annular negative pressure box and corresponding to the first ventilation hole, an annular negative pressure pipe disposed at the top of the hopper, a detachable connecting mechanism disposed between the annular negative pressure box and the annular negative pressure pipe, and a negative pressure dust collector connected to the annular negative pressure pipe; the annular metal filter plate is used to prevent plastic particles from being sucked in and to allow dust to be sucked in.

[0008] By adopting the above technical solution, when conveying plastic granules into the hopper, the feed inlet is first closed by the opening and closing mechanism, and the negative pressure dust collector is opened. During the process of conveying the plastic granules into the buffer bin, the dust in the plastic granules can be suctioned out by negative pressure. The flowing air carries the dust along the annular metal filter plate, the annular negative pressure box, and the annular negative pressure pipe into the negative pressure dust collector for filtration, so as to achieve negative pressure suction and collection of dust in the plastic granules (which will also be raised during the process of the plastic granules entering the buffer bin). After the dust in the buffer bin is suctioned out by negative pressure, the feed inlet is opened by the opening and closing mechanism, so that the plastic granules enter the hopper. Finally, the dust in the plastic granules in the buffer bin is suctioned out by negative pressure in batches, which can improve the dust removal effect and achieve efficient separation of dust in the plastic granules. At the same time, the annular metal filter plate needs to be cleaned during long-term use. The detachable setting of the connecting mechanism, combined with the sleeve installation of the annular negative pressure box, allows the annular negative pressure box to be disassembled for cleaning of the annular metal filter plate.

[0009] A further feature of the present invention is that: the inner ring of the annular negative pressure box is provided with an annular hole, the upper and lower ends of the inner ring of the annular negative pressure box are respectively provided with annular slots, the upper and lower edges of the annular metal filter plate are wrapped with annular rubber rings, the outer side of the annular rubber rings is embedded in the annular slots during installation, and the inner side of the annular rubber rings abuts against the periphery of the buffer chamber.

[0010] By adopting the above technical solution, the upper and lower edges of the annular metal filter plate are wrapped with annular rubber rings. The outer side of the annular rubber ring is embedded in the annular groove during installation to achieve a detachable connection between the annular metal filter plate and the annular negative pressure box. This facilitates cleaning after disassembling the annular metal filter plate and allows for the replacement of annular metal filter plates with different pore sizes to match plastic particles of different sizes. At the same time, the inner side of the annular rubber ring abuts against the periphery of the buffer chamber to ensure the sealing at the connection with the buffer chamber.

[0011] A further configuration of the present invention is as follows: the communication mechanism includes a plurality of connecting annular negative pressure pipes extending to the upper surface of the hopper and a plurality of insertion pipes disposed at the bottom of the annular negative pressure box and inserted into the insertion pipes; two sealing rings are embedded on the periphery of the insertion pipes to achieve sealing during insertion into the insertion pipes; and the insertion pipes are fixedly disposed with the top of the hopper.

[0012] By adopting the above technical solution, the connecting mechanism includes multiple connecting annular negative pressure pipes extending to the upper surface of the hopper, and multiple insertion pipes set at the bottom of the annular negative pressure box and inserted into the receiving seats. Two sealing rings are embedded on the periphery of the insertion pipes to achieve sealing during the insertion into the receiving seats, so as to realize the detachable connection between the annular negative pressure pipes and the annular negative pressure box.

[0013] A further embodiment of the present invention is that the opening and closing mechanism includes a flap hinged to the inside of the hopper, a drive cylinder disposed on the side of the hopper with its piston rod extending into the hopper, and a linkage arm hinged between the piston rod of the drive cylinder and the flap. The flap can open or close the feed inlet under the driving action of the drive cylinder.

[0014] By adopting the above technical solution, during the extension and retraction of the piston rod of the drive cylinder, the flip cover can be rotated through the linkage arm, so that the flip cover can open or close the feed port under the driving action of the drive cylinder.

[0015] A further configuration of the present invention is as follows: the opening and closing mechanism includes a plurality of fixed shafts disposed inside the hopper and surrounding the feed inlet, a cover plate telescopically disposed on the plurality of fixed shafts, a plurality of compression springs respectively sleeved on one end of the plurality of fixed shafts passing through the cover plate, and a plurality of anti-detachment end caps disposed at the lower end of the plurality of fixed shafts and preventing the compression springs from falling off. When a set amount of plastic particles are accumulated in the buffer chamber, the plurality of compression springs drive the cover plate to remain in the closed state of the feed inlet.

[0016] The annular negative pressure pipe is integrally formed with the upper surface of the hopper. The upper surface of the hopper is provided with multiple first connecting holes that connect to the annular negative pressure pipe. The lower surface of the annular negative pressure pipe is provided with multiple second connecting holes corresponding to the first connecting holes. The connecting mechanism includes a first rubber sealing sleeve provided at the first connecting hole, a second rubber sealing sleeve provided at the second connecting hole, a connecting pipe with one end extending and retracting inside the annular negative pressure box and the other end penetrating into the annular negative pressure pipe, a flexible sealing component provided between the upper end of the connecting pipe and the annular negative pressure box and not affecting the lifting and lowering of the connecting pipe, an annular connecting plate provided between multiple connecting pipes, and a lifting component provided between the annular negative pressure box and the annular connecting plate and driving the annular connecting plate to lift and lower. The connecting pipe is provided with a connecting port on the side near the inner wall of the hopper.

[0017] The first ventilation holes of the buffer compartment are arranged in multiple sets along the vertical direction. The annular connecting plate has an annular part that abuts against the periphery of the annular metal filter plate. Multiple sets of second ventilation holes are arranged on the annular part to correspond to or offset multiple sets of first ventilation holes.

[0018] When the connecting pipe moves upward to its limit, the connecting port of the connecting pipe is located inside the annular negative pressure pipe, and the lower surface of the connecting pipe is flush with the lower surface of the second rubber sealing sleeve. Multiple sets of first ventilation holes correspond to multiple sets of second through holes. When the connecting pipe moves downward to its limit, half of the connecting port of the connecting pipe is located inside the annular negative pressure pipe and the other half is located outside the annular negative pressure pipe. Multiple sets of first ventilation holes are staggered with multiple sets of second ventilation holes.

[0019] By adopting the above technical solution, when the lifting component drives the connecting pipe upward to its limit, the cover plate closes the feed inlet, and the connecting port of the connecting pipe is located inside the annular negative pressure pipe. Thus, during the process of plastic particles entering the buffer bin, the dust in the buffer bin is suctioned out by negative pressure. When the lifting component drives the connecting pipe downward to its limit, the cover plate opens the feed inlet, and half of the connecting port of the connecting pipe is located inside the annular negative pressure pipe and the other half is located outside the annular negative pressure pipe. Multiple sets of first ventilation holes and multiple sets of second ventilation holes are staggered, and the plastic particles in the buffer bin enter the hopper. At this time, the top of the hopper is suctioned out by negative pressure, and the dust raised during the process of plastic particles entering the hopper is suctioned out by negative pressure. At this time, the double-layer negative pressure suction ensures efficient separation of dust.

[0020] A further provision of the present invention is that the upper end of the connecting pipe is provided with an annular end, and the flexible sealing assembly includes a telescopic corrugated pipe, a first connecting ring provided at the upper end of the telescopic corrugated pipe and connected to the annular end, and a second connecting ring provided at the lower end of the telescopic corrugated pipe and connected to the annular negative pressure box.

[0021] By adopting the above technical solution, the telescopic corrugated pipe can be stretched, so that when the lifting component drives the connecting pipe to rise and fall, the connection between the connecting pipe and the annular negative pressure box can be sealed without affecting the expansion and contraction of the connecting pipe.

[0022] A further embodiment of the present invention is that: the top of the annular negative pressure box is detachably connected to an end cover by bolts, and the lifting assembly includes a lifting cylinder disposed on the end cover and a connecting joint disposed between the piston rod of the lifting cylinder and the annular connecting plate.

[0023] By adopting the above technical solution, the lifting assembly includes a lifting cylinder mounted on the end cover and a connecting joint mounted between the piston rod of the lifting cylinder and the annular connecting plate, thereby enabling the annular connecting plate and the connecting pipe to be lifted and lowered.

[0024] A further feature of the present invention is that the upper surface of the cover plate is provided with a protrusion extending into the buffer compartment, and the outer diameter of the protrusion gradually decreases along the vertically downward direction.

[0025] By adopting the above technical solution, a protrusion is provided on the upper surface of the cover plate, and the outer diameter of the protrusion gradually decreases along the vertical downward direction. This allows the plastic particles entering the buffer chamber to disperse around the protrusion after impacting it. On the one hand, this increases the degree of dust agitation in the plastic particles, and on the other hand, it allows the plastic particles to approach the annular metal filter plate, ultimately improving the effect of dust extraction and separation in the plastic particles.

[0026] A further provision of the present invention is that the negative pressure suction process for dust in plastic granules includes the following:

[0027] (S1) With the feed inlet closed by the cover plate, plastic granules are quantitatively fed into the buffer bin by an external automatic feeding system;

[0028] (S2) During the process of plastic particles entering the buffer chamber, the negative pressure dust collector is turned on. Air flows along the buffer chamber, the annular metal filter plate, the annular negative pressure box, the connecting pipe, and the annular negative pressure pipe before entering the negative pressure dust collector, so as to achieve negative pressure suction of dust in the plastic particles in the buffer chamber.

[0029] (S3) The lifting assembly drives the connecting pipe to move downward to its limit. The connecting pipe overcomes the elastic force of the compression spring so that the cover plate opens the feed port and the plastic particles flow into the hopper.

[0030] (S4) During the process of plastic particles flowing into the hopper, half of the connecting port of the connecting pipe is located inside the annular negative pressure pipe and the other half is located outside the annular negative pressure pipe. Multiple sets of first ventilation holes and multiple sets of second ventilation holes are staggered. Air enters the negative pressure dust collector along the top of the hopper, the connecting port of the connecting pipe, and the annular negative pressure pipe to achieve negative pressure suction of the dust at the top of the hopper.

[0031] (S5) The lifting assembly moves the cover plate upward to its limit, causing the cover plate to close the feed inlet;

[0032] (S6) Repeat (S1) to (S5) so that the plastic granules are quantitatively and repeatedly subjected to negative pressure dust removal before being transported into the hopper, thereby improving the effect of each negative pressure dust removal.

[0033] The beneficial effects of this invention are as follows: When conveying plastic granules into the hopper, the feed inlet is first closed by the opening and closing mechanism, and the negative pressure dust collector is opened. During the process of conveying the plastic granules into the buffer bin, the dust in the plastic granules can be suctioned out under negative pressure. The flowing air carries the dust along the annular metal filter plate, the annular negative pressure box, and the annular negative pressure pipe into the negative pressure dust collector for filtration, so as to achieve negative pressure suction and collection of dust in the plastic granules (which will also be raised during the process of the plastic granules entering the buffer bin). After the dust in the buffer bin is suctioned out under negative pressure, the feed inlet is opened by the opening and closing mechanism, so that the plastic granules enter the hopper. Finally, the dust in the plastic granules in the buffer bin is suctioned out under negative pressure in batches, which can improve the dust removal effect and achieve efficient separation of dust in the plastic granules. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a structural schematic diagram of Example 1;

[0036] Figure 2 This is an exploded view of a partial structure located at the hopper in Example 1;

[0037] Figure 3 This is a partial structural cross-sectional view of the hopper in Example 1;

[0038] Figure 4 yes Figure 3 A magnified view of the area located at point A;

[0039] Figure 5 yes Figure 3 A magnified view of the area located at point B;

[0040] Figure 6 This is a structural schematic diagram of Example 2;

[0041] Figure 7 yes Figure 6 A schematic diagram of a partial structure based on the basic structure (multiple sections are shown with cross-sectional lines).

[0042] Figure 8 yes Figure 7 A magnified view of the area located at point C.

[0043] In the diagram: 1. Extruder body; 2. Hopper; 21. Feed inlet; 22. First connecting hole; 3. Buffer bin; 31. First ventilation hole; 4. Dust removal device; 41. Annular negative pressure box; 411. Annular hole; 412. Annular groove; 413. End cap; 42. Annular metal filter plate; 421. Annular rubber ring; 43. Annular negative pressure pipe; 431. Second connecting hole; 44. Connecting mechanism; 441. Receiver; 442. Insert pipe; 4421. Sealing ring; 443. First rubber sealing sleeve; 444. Second rubber sealing sleeve; 445. Connecting pipe; 451. Connecting port; 4452. Annular end; 446. Flexible sealing assembly; 4461. Telescopic bellows; 4462. First connecting ring; 4463. Second connecting ring; 447. Annular connecting plate; 4471. Annular part; 4472. Second ventilation hole; 448. Lifting assembly; 4481. Lifting cylinder; 4482. Connecting joint; 45. Negative pressure dust collector; 5. Opening and closing mechanism; 51. Flip cover; 52. Drive cylinder; 53. Linkage arm; 54. Fixed shaft; 55. Cover plate; 551. Protrusion; 56. Compression spring; 57. Anti-detachment end cover. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] Example 1: An extruder for a large-diameter steel-reinforced composite pipe production line, such as... Figure 1 and Figure 2 As shown, the device includes an extruder body 1, a hopper 2 mounted on the extruder body 1, a feed inlet 21 on the top of the hopper 2, a buffer chamber 3 on the feed inlet 21, and a first ventilation hole 31 arranged in a circular array around the periphery of the buffer chamber 3. A dust removal device 4 is mounted on the top of the hopper 2 to perform negative pressure dust removal on the periphery of the buffer chamber 3. An external automatic feeding system is connected to the upper end of the buffer chamber 3.

[0046] like Figure 2 and Figure 3 As shown, the top of the hopper 2 is provided with an opening and closing mechanism 5 for opening or closing the feed inlet 21. The opening and closing mechanism 5 includes a flip cover 51 hinged inside the hopper 2, a drive cylinder 52 located on the side of the hopper 2 with its piston rod extending into the hopper 2, and a linkage arm 53 hinged between the piston rod of the drive cylinder 52 and the flip cover 51. The flip cover 51 can open or close the feed inlet 21 under the driving action of the drive cylinder 52.

[0047] like Figures 1 to 3 As shown, the dust removal device 4 includes an annular negative pressure box 41 sleeved around the buffer chamber 3, an annular metal filter plate 42 (without cross-section) disposed in the inner ring of the annular negative pressure box 41 and corresponding to the first ventilation hole 31, an annular negative pressure pipe 43 disposed at the top inside the hopper 2, a detachable communication mechanism 44 disposed between the annular negative pressure box 41 and the annular negative pressure pipe 43, and a negative pressure dust collector 45 communicating with the annular negative pressure pipe 43; the annular metal filter plate 42 is used to prevent plastic particles from being sucked in and to allow dust to be sucked in.

[0048] like Figures 3 to 5As shown, the inner ring of the annular negative pressure box 41 is provided with an annular hole 411, and the upper and lower ends of the inner ring of the annular negative pressure box 41 are respectively provided with annular grooves 412. The upper and lower edges of the annular metal filter plate 42 are wrapped with annular rubber rings 421. The outer side of the annular rubber ring 421 is embedded in the annular groove 412 during installation, and the inner side of the annular rubber ring 421 abuts against the periphery of the buffer chamber 3. The connecting mechanism 44 includes multiple receiving seats 441 that connect to the annular negative pressure pipes 43 and extend to the upper surface of the hopper 2, and multiple insertion pipes 442 that are provided at the bottom of the annular negative pressure box 41 and inserted into the receiving seats 441. Two sealing rings 4421 are embedded in the periphery of the insertion pipes 442 to achieve sealing during the insertion into the receiving seats 441. The receiving seats 441 are fixedly provided to the top of the hopper 2.

[0049] Implementation effect: When conveying plastic granules into hopper 2, the inlet 21 is first closed by the opening and closing mechanism 5, and the negative pressure dust collector 45 is opened. During the process of conveying the plastic granules into the buffer bin 3, the dust in the plastic granules can be suctioned out by negative pressure. The flowing air carries the dust along the annular metal filter plate 42, the annular negative pressure box 41, and the annular negative pressure pipe 43 into the negative pressure dust collector 45 for filtration, so as to achieve negative pressure suction and collection of dust in the plastic granules (which will also be raised during the process of the plastic granules entering the buffer bin 3); in the buffer bin 3 After the dust inside is collected by negative pressure suction, the feed port 21 is opened by the opening and closing mechanism 5, allowing the plastic particles to enter the hopper 2; finally, the dust in the plastic particles in the buffer bin 3 is collected by negative pressure in batches, which can improve the dust removal effect and achieve efficient separation of dust in the plastic particles; at the same time, the annular metal filter plate 42 needs to be cleaned during long-term use. The detachable setting of the connecting mechanism 44, combined with the sleeve installation of the annular negative pressure box 41, allows the annular negative pressure box 41 to be disassembled to clean the annular metal filter plate 42.

[0050] The upper and lower edges of the annular metal filter plate 42 are wrapped with annular rubber rings 421. The outer side of the annular rubber rings 421 is embedded in the annular grooves 412 during installation to achieve a detachable connection between the annular metal filter plate 42 and the annular negative pressure box 41. This facilitates cleaning after disassembling the annular metal filter plate 42 and allows for the replacement of annular metal filter plates 42 with different apertures to match plastic particles of different sizes. At the same time, the inner side of the annular rubber rings 421 abuts against the periphery of the buffer chamber 3 to ensure a tight seal at the connection with the buffer chamber 3. The connecting mechanism 44 includes multiple receiving seats 441 that connect to the annular negative pressure pipes 43 and extend to the upper surface of the hopper 2, and multiple insertion pipes 442 that are located at the bottom of the annular negative pressure box 41 and inserted into the receiving seats 441. Two sealing rings 4421 are embedded on the periphery of the insertion pipes 442 to achieve a seal during insertion into the receiving seats 441, thereby achieving a detachable connection between the annular negative pressure pipes 43 and the annular negative pressure box 41. During the extension and retraction of the piston rod of the drive cylinder 52, the flip cover 51 can be rotated through the linkage arm 53, so that the flip cover 51 can open or close the feed port 21 under the driving action of the drive cylinder 52.

[0051] Example 2: An extruder for a large-diameter steel-reinforced composite pipe production line, such as... Figure 6 and Figure 7 As shown, it includes an extruder body 1 and a hopper 2 disposed on the extruder body 1. The top of the hopper 2 is provided with a feed inlet 21, and a buffer chamber 3 is provided on the feed inlet 21. The buffer chamber 3 is provided with a first ventilation hole 31 arranged in a circumferential array on its periphery. The top of the hopper 2 is provided with a dust removal device 4 for performing negative pressure dust removal on the periphery of the buffer chamber 3.

[0052] like Figure 7 and Figure 8 As shown, the top of the hopper 2 is provided with an opening and closing mechanism 5 for opening or closing the feed inlet 21. The opening and closing mechanism 5 includes multiple fixed shafts 54 disposed inside the hopper 2 and surrounding the feed inlet 21, cover plates 55 telescopically disposed on the multiple fixed shafts 54, multiple compression springs 56 respectively sleeved on the multiple fixed shafts 54 passing through one end of the cover plates 55, and multiple anti-detachment end caps 57 disposed at the lower end of the multiple fixed shafts 54 to prevent the compression springs 56 from falling off. When a set amount of plastic particles are accumulated in the buffer bin 3, the multiple compression springs 56 drive the cover plates 55 to keep the feed inlet 21 closed.

[0053] like Figures 6 to 8As shown, the dust removal device 4 includes an annular negative pressure box 41 sleeved around the buffer chamber 3, an annular metal filter plate 42 disposed in the inner ring of the annular negative pressure box 41 and corresponding to the first ventilation hole 31, an annular negative pressure pipe 43 disposed at the top inside the hopper 2, a detachable communication mechanism 44 disposed between the annular negative pressure box 41 and the annular negative pressure pipe 43, and a negative pressure dust collector 45 communicating with the annular negative pressure pipe 43; the annular metal filter plate 42 is used to prevent plastic particles from being sucked in and to allow dust to be sucked in.

[0054] In conjunction with Example 1 Figure 4 As shown, the inner ring of the annular negative pressure box 41 is provided with an annular hole 411, and the upper and lower ends of the inner ring of the annular negative pressure box 41 are respectively provided with annular grooves 412. The upper and lower edges of the annular metal filter plate 42 are wrapped with annular rubber rings 421. The outer side of the annular rubber ring 421 is embedded in the annular groove 412 during installation, and the inner side of the annular rubber ring 421 abuts against the periphery of the buffer chamber 3.

[0055] like Figure 7 and Figure 8 As shown. The annular negative pressure pipe 43 is integrally formed with the upper surface of the hopper 2. The upper surface of the hopper 2 is provided with multiple first connecting holes 22 that connect to the annular negative pressure pipe 43. The lower surface of the annular negative pressure pipe 43 is provided with multiple second connecting holes 431 corresponding to the first connecting holes 22. The connecting mechanism 44 includes a first rubber sealing sleeve 443 provided at the first connecting hole 22, a second rubber sealing sleeve 444 provided at the second connecting hole 431, a connecting pipe 445 with one end extending and retracting inside the annular negative pressure box 41 and the other end penetrating into the annular negative pressure pipe 43, a flexible sealing component 446 provided between the upper end of the connecting pipe 445 and the annular negative pressure box 41 and not affecting the lifting and lowering of the connecting pipe 445, an annular connecting plate 447 provided between the multiple connecting pipes 445, and a lifting component 448 provided between the annular negative pressure box 41 and the annular connecting plate 447 and driving the annular connecting plate 447 to lift and lower. A connecting port 4451 is provided on the side of the connecting pipe 445 near the inner wall of the hopper 2.

[0056] like Figure 7 and Figure 8As shown, the buffer compartment 3 has multiple sets of first ventilation holes 31 arranged vertically. The annular connecting plate 447 has an annular portion 4471 that abuts against the periphery of the annular metal filter plate 42. Multiple sets of second ventilation holes 4472 are arranged on the annular portion 4471 to correspond to or offset multiple sets of first ventilation holes 31. When the connecting pipe 445 moves upward to its limit, the connecting port 4451 of the connecting pipe 445 is located inside the annular negative pressure pipe 43, and the lower surface of the connecting pipe 445 is flush with the lower surface of the second rubber sealing sleeve 444. The multiple sets of first ventilation holes 31 correspond to multiple sets of second through holes. When the connecting pipe 445 moves downward to its limit, half of the connecting port 4451 of the connecting pipe 445 is located inside the annular negative pressure pipe 43 and the other half is located outside the annular negative pressure pipe 43. The multiple sets of first ventilation holes 31 are offset from the multiple sets of second ventilation holes 4472.

[0057] like Figure 7 and Figure 8 As shown, the upper end of the connecting pipe 445 is provided with an annular end 4452. The flexible sealing assembly 446 includes a telescopic bellows 4461, a first connecting ring 4462 located at the upper end of the telescopic bellows 4461 and connected to the annular end 4452, and a second connecting ring 4463 located at the lower end of the telescopic bellows 4461 and connected to the annular negative pressure box 41. The top of the annular negative pressure box 41 is detachably connected to an end cap 413 by bolts. The lifting assembly 448 includes a lifting cylinder 4481 located on the end cap 413 and a connecting joint 4482 located between the piston rod of the lifting cylinder 4481 and the annular connecting plate 447. The upper surface of the cover plate 55 is provided with a protrusion 551 extending into the buffer compartment 3, and the outer diameter of the protrusion 551 gradually decreases in the vertically downward direction.

[0058] The negative pressure suction process for dust in plastic granules in this embodiment includes the following:

[0059] (S1) With the cover plate 55 closing the feed port 21, the plastic granules are quantitatively fed into the buffer bin 3 by an external automatic feeding system;

[0060] (S2) During the process of plastic particles entering the buffer chamber 3, the negative pressure dust collector 45 is turned on. Air flows along the buffer chamber 3, the annular metal filter plate 42, the annular negative pressure box 41, the connecting pipe 445, and the annular negative pressure pipe 43 and then enters the negative pressure dust collector 45 to achieve negative pressure suction of dust in the plastic particles in the buffer chamber 3.

[0061] (S3) The lifting assembly 448 drives the connecting pipe 445 to move downward to the limit state. The connecting pipe 445 overcomes the elastic force of the compression spring 56 so that the cover plate 55 opens the feed port 21 and the plastic particles flow into the hopper 2.

[0062] (S4) During the process of plastic particles flowing into the hopper 2, half of the connecting port 4451 of the connecting pipe 445 is located inside the annular negative pressure pipe 43 and the other half is located outside the annular negative pressure pipe 43. Multiple sets of first ventilation holes 31 and multiple sets of second ventilation holes 4472 are staggered. Air enters the negative pressure dust collector 45 along the top of the hopper 2, the connecting port 4451 of the connecting pipe 445, and the annular negative pressure pipe 43 to achieve negative pressure suction of the dust on the top of the hopper 2.

[0063] (S5) The lifting assembly 448 drives the cover plate 55 to move upward to its limit, so that the cover plate 55 is in the state of closing the feed inlet 21;

[0064] (S6) Repeat (S1) to (S5) so that the plastic granules are quantitatively and repeatedly subjected to negative pressure dust removal before being conveyed into hopper 2, thereby improving the effect of each negative pressure dust removal.

[0065] Working principle: When the lifting component 448 drives the connecting pipe 445 to move upward to its limit, the cover plate 55 closes the feed inlet 21. The connecting port 4451 of the connecting pipe 445 is located inside the annular negative pressure pipe 43, thereby achieving negative pressure suction of dust in the buffer chamber 3 during the process of plastic particles entering the buffer chamber 3. When the lifting component 448 drives the connecting pipe 445 to move downward to its limit, the cover plate 55 opens the feed inlet 21. Half of the connecting port 4451 of the connecting pipe 445 is located inside the annular negative pressure pipe 43 and the other half is located outside the annular negative pressure pipe 43. Multiple sets of first ventilation holes 31 and multiple sets of second ventilation holes 4472 are staggered. The plastic particles in the buffer chamber 3 enter the hopper 2. At this time, negative pressure suction is achieved on the top of the hopper 2, and further negative pressure suction is performed on the dust raised during the process of plastic particles entering the hopper 2. At this time, the double-layer negative pressure suction ensures efficient separation of dust.

[0066] The telescopic corrugated pipe 4461 can be stretched, so that when the lifting assembly 448 drives the connecting pipe 445 to rise and fall, the connection between the connecting pipe 445 and the annular negative pressure box 41 can be sealed without affecting the extension and retraction of the connecting pipe 445. The lifting assembly 448 includes a lifting cylinder 4481 set on the end cover 413 and a connecting joint 4482 set between the piston rod of the lifting cylinder 4481 and the annular connecting plate 447, thereby enabling the annular connecting plate 447 and the connecting pipe 445 to rise and fall. The upper surface of the cover plate 55 is provided with a protrusion 551, and the outer diameter of the protrusion 551 gradually decreases in the vertical downward direction, so that the plastic particles entering the buffer chamber 3 can be dispersed around the protrusion 551 after impacting it. On the one hand, this increases the degree of dust agitation in the plastic particles, and on the other hand, it allows the plastic particles to approach the annular metal filter plate 42, ultimately improving the effect of dust extraction and separation in the plastic particles.

Claims

1. An extruder for a large-diameter steel-reinforced composite pipe production line, comprising an extruder body (1) and a hopper (2) disposed on the extruder body (1), characterized in that: The hopper (2) is provided with a feed inlet (21) at the top, and a buffer chamber (3) is provided on the feed inlet (21). The buffer chamber (3) is provided with a first ventilation hole (31) arranged in a circular array on its periphery. The hopper (2) is provided with a dust removal device (4) for performing negative pressure dust removal on the periphery of the buffer chamber (3) at the top. The hopper (2) is provided with an opening and closing mechanism (5) for opening or closing the feed inlet (21) at the top. The dust removal device (4) includes a sleeve fitted around the periphery of the buffer chamber (3). The annular negative pressure box (41), the annular metal filter plate (42) disposed in the inner ring of the annular negative pressure box (41) and corresponding to the first ventilation hole (31), the annular negative pressure pipe (43) disposed at the top of the hopper (2), the detachable communication mechanism (44) disposed between the annular negative pressure box (41) and the annular negative pressure pipe (43), and the negative pressure dust collector (45) connected to the annular negative pressure pipe (43); the annular metal filter plate (42) is used to prevent plastic particles from being sucked and to allow dust to be sucked.

2. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 1, characterized in that: The inner ring of the annular negative pressure box (41) is provided with an annular hole (411). The upper and lower ends of the inner ring of the annular negative pressure box (41) are respectively provided with annular slots (412). The upper and lower edges of the annular metal filter plate (42) are wrapped with annular rubber rings (421). The outer side of the annular rubber ring (421) is embedded in the annular slot (412) during installation. The inner side of the annular rubber ring (421) abuts against the periphery of the buffer chamber (3).

3. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 1, characterized in that: The connecting mechanism (44) includes multiple connecting annular negative pressure pipes (43) extending to the upper surface of the hopper (2) and multiple insertion pipes (442) disposed at the bottom of the annular negative pressure box (41) and inserted into the insertion pipes (441). Two sealing rings (4421) are embedded on the periphery of the insertion pipes (442) to achieve sealing during the insertion into the insertion pipes (441). The insertion pipes (442) are fixedly disposed at the top of the hopper (2).

4. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 1, characterized in that: The opening and closing mechanism (5) includes a flap (51) hinged in the hopper (2), a drive cylinder (52) located on the side of the hopper (2) with its piston rod extending into the hopper (2), and a linkage arm (53) hinged between the piston rod of the drive cylinder (52) and the flap (51). The flap (51) can open or close the feed inlet (21) under the drive of the drive cylinder (52).

5. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 1, characterized in that: The opening and closing mechanism (5) includes multiple fixed shafts (54) arranged inside the hopper (2) and surrounding the feed inlet (21), cover plates (55) telescopically arranged on the multiple fixed shafts (54), multiple compression springs (56) respectively sleeved on the multiple fixed shafts (54) passing through one end of the cover plate (55), and multiple anti-detachment end caps (57) arranged at the lower end of the multiple fixed shafts (54) to prevent the compression springs (56) from falling off. When a set amount of plastic particles are accumulated in the buffer bin (3), the multiple compression springs (56) drive the cover plates (55) to keep the feed inlet (21) closed. The annular negative pressure pipe (43) is integrally formed with the upper surface of the hopper (2). The upper surface of the hopper (2) is provided with a plurality of first connecting holes (22) connecting the annular negative pressure pipe (43). The lower surface of the annular negative pressure pipe (43) is provided with a plurality of second connecting holes (431) corresponding to the first connecting holes (22). The connecting mechanism (44) includes a first rubber sealing sleeve (443) provided at the first connecting hole (22), a second rubber sealing sleeve (444) provided at the second connecting hole (431), and one end extending and retracting inside the annular negative pressure box (41). The other end of the connecting pipe (445) is inserted into the annular negative pressure pipe (43), the flexible sealing component (446) is set between the upper end of the connecting pipe (445) and the annular negative pressure box (41) and does not affect the lifting of the connecting pipe (445), the annular connecting plate (447) is set between multiple connecting pipes (445), and the lifting component (448) is set between the annular negative pressure box (41) and the annular connecting plate (447) and drives the annular connecting plate (447) to lift. The connecting pipe (445) has a connecting port (4451) on the side near the inner wall of the hopper (2). The first ventilation holes (31) of the buffer compartment (3) are arranged in multiple sets along the vertical direction. The annular connecting plate (447) has an annular portion (4471) that abuts against the periphery of the annular metal filter plate (42). Multiple sets of second ventilation holes (4472) are arranged on the annular portion (4471) to correspond to or offset multiple sets of first ventilation holes (31). When the connecting pipe (445) moves upward to its limit, the connecting port (4451) of the connecting pipe (445) is located inside the annular negative pressure pipe (43), the lower surface of the connecting pipe (445) is flush with the lower surface of the second rubber sealing sleeve (444), and multiple sets of first ventilation holes (31) correspond to multiple sets of second through holes; when the connecting pipe (445) moves downward to its limit, half of the connecting port (4451) of the connecting pipe (445) is located inside the annular negative pressure pipe (43) and the other half is located outside the annular negative pressure pipe (43), and multiple sets of first ventilation holes (31) are staggered with multiple sets of second ventilation holes (4472).

6. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 5, characterized in that: The upper end of the connecting pipe (445) is provided with an annular end (4452), and the flexible sealing assembly (446) includes a telescopic bellows (4461), a first connecting ring (4462) provided at the upper end of the telescopic bellows (4461) and connected to the annular end (4452), and a second connecting ring (4463) provided at the lower end of the telescopic bellows (4461) and connected to the annular negative pressure box (41).

7. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 5, characterized in that: The top of the annular negative pressure box (41) is detachably connected to an end cap (413) by bolts. The lifting assembly (448) includes a lifting cylinder (4481) disposed on the end cap (413) and a connecting joint (4482) disposed between the piston rod of the lifting cylinder (4481) and the annular connecting plate (447).

8. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 5, characterized in that: The upper surface of the cover plate (55) is provided with a protrusion (551) extending into the buffer compartment (3), and the outer diameter of the protrusion (551) gradually decreases in the vertical downward direction.

9. The extruder for a large-diameter steel-reinforced composite pipe production line according to claim 5, characterized in that: The process of negative pressure suction to remove dust from plastic granules includes the following: (S1) With the cover plate (55) closing the feed inlet (21), the plastic granules are quantitatively fed into the buffer bin (3) by an external automatic feeding system; (S2) During the process of plastic particles entering the buffer chamber (3), the negative pressure dust collector (45) is turned on. Air flows along the buffer chamber (3), the annular metal filter plate (42), the annular negative pressure box (41), the connecting pipe (445), and the annular negative pressure pipe (43) and then enters the negative pressure dust collector (45) to achieve negative pressure suction of dust in the plastic particles in the buffer chamber (3); (S3) The lifting assembly (448) drives the connecting pipe (445) to move downward to the limit state. The connecting pipe (445) overcomes the elastic force of the compression spring (56) so that the cover plate (55) opens the feed port (21) and the plastic particles flow into the hopper (2). (S4) During the process of plastic particles flowing into the hopper (2), half of the connecting port (4451) of the connecting pipe (445) is located inside the annular negative pressure pipe (43) and the other half is located outside the annular negative pressure pipe (43). Multiple sets of first ventilation holes (31) and multiple sets of second ventilation holes (4472) are staggered. Air enters the negative pressure dust collector (45) along the top of the hopper (2), the connecting port (4451) of the connecting pipe (445), and the annular negative pressure pipe (43) to achieve negative pressure suction of the dust on the top of the hopper (2). (S5) The lifting assembly (448) drives the cover plate (55) to move upward to its limit, so that the cover plate (55) is in the state of closing the feed inlet (21); (S6) Repeat (S1) to (S5) so that the plastic particles are quantitatively and repeatedly subjected to negative pressure dust removal and then transported into the hopper (2) to improve the effect of each negative pressure dust removal.

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