Modified plastic extrusion granulator

Abstract

The invention relates to the technical field of granulators, in particular to a modified plastic extrusion granulator, which comprises an extruder, a pelletizing chamber, a water feeding device, a motor, a material receiving device, a template and a pelletizing module, the extruder comprises a main body and an external expansion section, the template is coaxially connected with the external expansion section, the template is provided with a hole ring I, a hole ring II and a hole ring III, and the hole ring II, the hole ring II and the hole ring III are coaxially connected. The pelletizing module is connected to the left side of the motor and comprises a cutter head, the cutter head is located on the right side of the template, a first cutter, a second cutter and a third cutter are arranged on the left end face of the cutter head from inside to outside in a circumferential array mode, and the first cutter, the second cutter and the third cutter are driven by the motor to rotate synchronously and conduct differential pelletizing on the first hole ring, the second hole ring and the third hole ring. According to the invention, through modular design of the cutters and a mode that the pelletizing speeds of the cutters of different modules are different, the purpose of uniform size of pelletized particles is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of granulators, in particular to a modified plastic extrusion granulator. Background Art

[0002] Modified plastics are obtained by blending ordinary plastics with additives. They will improve their own properties or have one or more additional properties. For example, the mechanical properties, thermal properties and chemical properties of modified resins are improved after modification. In order to facilitate the processing of raw materials, modified plastics are often made into granules, and the extrusion granulator is the key equipment for granulating modified plastics. Common modified plastic extrusion granulators can be divided into water-cooled strand pelletizers and underwater pelletizers according to their working principles. The underwater pelletizer has broad development prospects due to its high pelletizing speed and space saving brought by its compact structure.

[0003] The underwater pelletizer includes an extrusion part and a pelletizing part. The principle is as follows: the extrusion part directly extrude the molten plastic from the die hole on the template, while the extruded molten plastic is cut off by the rotation of the knife disc, and solidified and moved upward by the cooling water in the pelletizing chamber. There is a section of expansion pipe at the discharge end of the extrusion part. The purpose is to gradually increase the cross-section of the flowing raw material while discharging the plastic raw material output from the thinner pipe of the extrusion part to the template, so that each part of the raw material is pressed evenly, avoiding the phenomenon of different granulation sizes caused by different extrusion speeds from different die holes on the template. In order to achieve the above effect, the expansion pipe must have a certain length in both the radial and axial directions, but the raw material close to the pipe wall will lose more temperature, so the increase in the length of the expansion pipe will also make the temperature of the internal raw material more uneven, resulting in a large difference in the fluidity of the raw material, thereby causing the phenomenon of different granulation sizes again. In order to solve this problem, the prior art often arranges a heating belt on the expansion pipe to compensate for the temperature lost at the pipe wall. For example, in an underwater pelletizing system of a large plastic extrusion granulation unit with publication number CN103878898B, the temperature difference of the template granulation belt is reduced through the heat exchange pipeline inside the template, so that the flow of plastic at the template storage is uniform, thereby avoiding the problem of uneven size of granulated particles.

[0004] However, when granulating certain materials, the heating belt will also have a negative impact. For example, when granulating modified resins, the heating belt will increase the temperature of the outer expansion section tube wall, and the high temperature of the inner wall of the outer expansion section will accelerate the speed of carbide formation of the modified resin. The carbides adhering to the inner wall of the outer expansion section will affect the thermal conductivity, and the formation of carbides is uneven. Correspondingly, the impact on the temperature of the raw materials at different locations is also uneven, so the fluidity of the raw materials will be uneven, and there is still the problem of uneven granulation size.

[0005] Therefore, in order to avoid the problem that the heating belt causes the granulated particles to be of different sizes, a modified plastic extrusion granulator is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a modified plastic extrusion granulator, which solves the problem that the heating belt on the expansion section during the modified resin granulation process will cause the granulated particles to be of different sizes. Through the modular design of the cutter and the different cutting speeds of the cutters in different modules, the purpose of making the granulated particles of uniform size is achieved without the need for a heating belt.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A modified plastic extrusion granulator comprises an extruder, a pelletizing chamber, a water supply device, a motor, a material receiving device, a template and a pelletizing module. The extruder comprises a main body and an outward expansion section. The template is coaxially connected to the outward expansion section. A hole ring 1, a hole ring 2 and a hole ring 3 are provided on the template. The pelletizing module is transmission-connected to the motor and comprises a cutter disc. The cutter disc is located on the right side of the template. A cutter 1, a cutter 2 and a cutter 3 are arranged in a circular array from inside to outside on the left end surface of the cutter disc. The cutter 1, the cutter 2 and the cutter 3 are driven by the motor to rotate synchronously and pelletize the hole ring 1, the hole ring 2 and the hole ring 3 at differential speeds.

[0009] Preferably, the pelletizing module also includes a knife shaft and a pressure plate, the right end of the knife shaft is connected to the motor spindle, the pressure plate is nested on the knife shaft, the knife disc also includes a disc body, a fixed rod, pressure ring one, pressure ring two and pressure ring three, the disc body is nested in the left end of the knife shaft, a plurality of fixed rods are connected to the left side of the disc body, pressure ring one, pressure ring two and pressure ring three are all connected to the left side of the fixed rod, and the projections of the three on the right side surface of the template along the left and right directions respectively cover hole ring one, hole ring two and hole ring three, the cutter one, cutter two and cutter three are respectively arranged in a circular array on pressure ring one, pressure ring two and pressure ring three, and the number of arrays of the three is different.

[0010] The plurality of cutters one, two and three are modularized respectively by means of the pressure ring one, the pressure ring two and the pressure ring three, and by adjusting the number of arrays of the cutters on the pressure ring, the pelletizing speeds on the hole ring one, the hole ring two and the hole ring three are made different, and the uniformity of the pelletizing particles is regulated by adjusting the pelletizing speed.

[0011] Preferably, the fixing rod is detachably connected to the disc body, and the pressure ring 1, pressure ring 2 and pressure ring 3 are all non-detachably connected to the fixing rod. On the one hand, the number of fixing rods cannot be too many, otherwise it will affect the discharge of particles, so the connection area between the fixing rod and the pressure ring is limited, and better stability can be guaranteed by the non-detachable connection. On the other hand, the connection between the disc body and the knife shaft is inconvenient to disassemble and assemble, and frequent disassembly and assembly will affect the stability of the connection, so the fixing rod and the disc body are detachably connected to facilitate the disassembly and assembly of the pressure ring, thereby facilitating the adjustment of the cutter spacing, so that the granulated particles can ensure good uniformity under a variety of pelletizing environments.

[0012] Preferably, a plurality of the fixing rods are arranged in a circular array on the left side of the disc body. The circular array makes the fixing rods evenly distributed on the disc body, and the connection points are evenly distributed, avoiding stress concentration, thereby fixing the pressure ring more stably. The fixing rods are inclined to the radial direction of the disc body, so that the contact area between the fixing rods and the disc body is larger, thereby forming a more stable connection. Through the above arrangement, the connection of the cutter on the disc body is more stable, so as to achieve a more uniform and stable granulation effect.

[0013] Preferably, a resistance reducing surface is provided on a portion of the fixing rod that is not connected to the cutter disc. The resistance reducing surface is arranged on the right side surface of the fixing rod, and the resistance reducing surface is inclined toward the direction of movement of the cutter.

[0014] Through the above scheme, the resistance of water flow to the rotation of the disc body is reduced, and the impact of the fixed rod on the formed particles is avoided.

[0015] Preferably, the pressure ring 1 includes a fixed ring and a movable ring, the fixed ring is connected to the left side of the fixed rod, the movable ring is connected to the left side of the fixed ring, a slide groove is opened inside the fixed ring, the slide groove is concentric with the fixed ring, and a circular array of slots is provided on the movable ring, and the number of slots is the same as the number of cutters 1. By setting the number of slots on the movable ring, the number of cutters 1 on the pressure ring can be adjusted, and then the pelletizing speed can be adjusted.

[0016] The slot passes through the left and right sides of the moving ring. The cutter 1 includes a tail, a blade body and a blade head. The tail is matched and installed in the slide slot. The blade head fits the right side of the template. The blade body connects the tail and the blade head, and the blade body is located inside the slot. Through the cooperation of the slide slot and the blade head, the cutter is positioned along the axial and radial directions of the fixed ring; through the cooperation of the slot and the blade body, the cutter is positioned along the circumferential direction of the fixed ring, so that the cutter 1 is fixed on the pressure ring 1. The pressure ring 2 and the pressure ring 3 also have a moving ring and a fixed ring. The cutter 2 and the cutter 3 also include a tail, a blade body and a blade head.

[0017] Preferably, the minimum distance from the cutter head to the fixed ring is recorded as h, and h is not less than the diameter of the granulated particles, the spacing between the fixed ring on the first pressure ring and the fixed ring on the second pressure ring is greater than the spacing between the fixed ring on the second pressure ring and the fixed ring on the third hole pressure ring, and the spacing between the fixed ring on the second pressure ring and the fixed ring on the third pressure ring is not less than the diameter of the granulated particles. By setting the spacing, it can ensure that the granulated particles can be discharged normally and the particles can be better kept spherical.

[0018] Preferably, a cutting edge is provided on the slide groove so that the cutter can be freely disassembled and assembled. Furthermore, the cutting edges on the pressure rings 1, 2 and 3 are arranged along any radius of the disk body, and a closing pin is installed in the cutting edge, so that multiple cutting edges can be controlled by one closure, which facilitates the disassembly and assembly of the cutter.

[0019] Preferably, the inner ring of the fixed ring has a taper, and the major diameter of the inner ring of the fixed ring is on the right side. A drainage groove is arranged on the right side surface of the fixed ring, and the drainage groove is distributed on the edge of the fixed ring so that the water pressure on the right side of the fixed ring is locally reduced, so that the granulated particles are entrained by the water flow and discharged from the gap of the fixed ring.

[0020] Preferably, the fixed ring on the pressure ring two and the pressure ring three has an extension section, which is arranged on the left side of the fixed ring and has a taper consistent with the inner ring of the fixed ring to avoid particles being discharged radially along the disk body and thus being cut twice by the cutter.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention adopts modular design of the cutter on the cutter disc, so that the cutting speed of the cutter for the raw material particles in the inner and outer circles of the template is different, so as to solve the problem of different sizes of granulated particles caused by different fluidity of raw materials inside the expansion section, avoid the use of heating belts, and save the production cost of the granulator.

[0023] 2. The present invention designs the pressure ring on the cutter disc so that each pressure ring can independently control the number of cutters installed to achieve different pelletizing speeds, and the design of the knife inlet on the pressure ring facilitates the installation and removal of the cutter on the pressure ring.

[0024] 3. The present invention avoids secondary cutting of the granulated particles by designing the extension section on the fixed ring, and slows down the water flow between the template and the knife disc, so that the granulated particles can be better spheroidized with the help of higher water temperature. In addition, the extension section and the taper of the fixed ring cooperate with the drainage groove to discharge the particles more smoothly to the receiving pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall right-side section isometric structure of the present invention;

[0026] Figure 2 For the present invention Figure 1 The enlarged schematic diagram of part A in the middle;

[0027] Figure 3 It is a schematic diagram of the overall left-side equiaxed structure of the present invention;

[0028] Figure 4 For the present invention Figure 3 The enlarged schematic diagram of part B in the middle;

[0029] Figure 5 For the present invention Figure 2 The enlarged schematic diagram of part C in the middle;

[0030] Figure 6 It is a schematic diagram of the overall left-side cross-sectional structure of the present invention;

[0031] Figure 7 For the present invention Figure 2 The enlarged schematic diagram of part D in the middle;

[0032] Figure 8 It is a schematic diagram of the overall full-section equiaxed side structure of the present invention;

[0033] Fig. 9 For the present invention Figure 8 Enlarged schematic diagram of part E in the middle.

[0034] In the figure: 1, extruder; 11, main body; 12, expansion section; 2, pelletizing chamber; 3, water supply device; 4, motor; 5, material receiving device; 6, template; 61, hole ring 1; 62, hole ring 2; 63, hole ring 3; 7, pelletizing module; 71, knife disc; 711, cutter 1; 7111, knife tail; 7112, knife body; 7113, knife head; 712, cutter 2; 713, cutter 3; 714, disk body; 715, fixing rod; 7151, resistance reduction surface; 716, pressure ring 1; 7161, fixed ring; 71611, slide groove; 71612, knife edge; 71613, closing pin; 71614, drainage groove; 71615, extension section; 7162, moving ring; 71621, slot; 717, pressure ring 2; 718, pressure ring 3; 72, knife shaft; 73, pressure plate. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figures 1 to 9 The present invention provides a modified plastic extrusion granulator, and the technical solution is as follows:

[0037] A modified plastic extrusion granulator comprises an extruder 1, a pelletizing chamber 2, a water supply device 3, a motor 4, a material receiving device 5, a template 6 and a pelletizing module 7. The extruder 1 comprises a main body 11 and an expansion section 12. The pelletizing chamber 2 is bolted to the right side of the expansion section 12, and a high temperature resistant sealing gasket is added between the two to ensure the sealing performance. The water supply device 3 is usually composed of a water pump and a water pipe. The water pump of the water supply device 3 is arranged at the rear side of the pelletizing chamber 2 and is connected to the pelletizing chamber 2 through a water pipe connected to the lower end of the pelletizing chamber 2. The motor 4 is installed on a frame. The motor 4 should have a certain movable space in the left and right directions so that after connecting to the pelletizing module 7 described below, the knife retreat and knife advance actions can be realized. The function of the material receiving device 5 is to receive and dry the material, which comprises a water pump arranged at The material receiving box in front of the pelletizing chamber 2, and the water pipe connecting the material receiving box and the upper end of the pelletizing chamber 2, the main body 11 has a screw stirring device and a heating device inside, the ordinary plastic particles added to the main body 11 are crushed and heated to a molten state, so as to be mixed with the additive to complete the modification, and the modified resin will form carbides under high temperature, so the underwater pelletizer used for modified resin granulation usually needs to regularly clean the template 6 and the expansion section, in order to avoid the high temperature of the heating belt on the expansion section to accelerate the formation of carbides, and also to save the energy consumption of the heating belt, the present invention considers canceling the heating belt to slow down the accumulation of carbides, and the problem of different granulation sizes after canceling the heating belt is solved by improving the pelletizing module 7. The template 6 is coaxially connected to the expansion section 12, and the template 6 is provided with a hole ring 1 61, a hole ring 2 62 and a hole ring 3 63, which is only for simplifying the description here. In actual production, more hole rings are often set on the template 6 to improve the efficiency of granulation. The pelletizing module 7 is connected to the left side of the motor 4, and the pelletizing module 7 includes a knife disc 71, which is located on the right side of the template 6, and the left end face of the knife disc 71 is provided with a cutter 1 711, a cutter 2 712 and a cutter 3 713 in a circular array from the inside to the outside. By splitting the originally integrated cutter, each hole ring has its own corresponding cutter module. The cutter 1 711, the cutter 2 712 and the cutter 3 713 are driven by the motor 4 to rotate synchronously and perform differential pelletizing on the hole ring 1 61, the hole ring 2 62 and the hole ring 3 63. By adjusting the cutter module, the pelletizing speed of the cutter on the hole ring can be further regulated to ensure the uniformity of the granulated particles under different working conditions.

[0038] As an embodiment of the present invention, refer to Figure 1 and Figure 2The pelletizing module 7 also includes a knife shaft 72 and a pressure plate 73. The right end of the knife shaft 72 is connected to the main shaft of the motor 4 through a coupling. The pressure plate 73 is nested on the knife shaft 72. When the knife shaft 72 moves to the left, the sealing of the pelletizing chamber 2 is completed with the help of a locking device. The knife disc 71 also includes a disc body 714, a fixed rod 715, a pressure ring 1 716, a pressure ring 2 717 and a pressure ring 3 718. The disc body 714 is nested at the left end of the knife shaft 72. A plurality of fixed rods 715 are connected to the left side of the disc body 714. The pressure ring 1 716, the pressure ring 2 717 and the pressure ring 3 718 are all connected to the left side of the fixed rod 715. The projections of the three on the right side of the template 6 in the left and right directions respectively cover the hole ring 1 61, the hole ring 2 62 and the hole ring 3 63. The cutter Cutters one 711, two 712 and three 713 are arranged in a circular array on pressure ring one 716, pressure ring two 717 and pressure ring three 718 respectively. The multiple cutters one 711, two 712 and three 713 are modularized by pressure ring one 716, pressure ring two 717 and pressure ring three 718 respectively, and the modularized cutters correspond to the hole rings respectively, so that the pelletizing parameters of each hole ring can be independently controlled to avoid the isotropy of the integrated cutter during pelletizing.

[0039] Cutter 1 711, Cutter 2 712 and Cutter 3 713 are arranged in different numbers on pressure ring 1 716, pressure ring 2 717 and pressure ring 3 718 respectively. The diameter of the pressure ring is fixed, and the spacing between the cutters can be adjusted by adjusting the number of cutter arrays. In addition, the number of holes on the hole ring is also fixed, so the fewer the number of cutters in the array, the larger the spacing between the cutters. Accordingly, the longer the interval between two adjacent cutters passing through the same hole on the hole ring is, so that the particles can be squeezed out more fully, so as to obtain a larger volume after cutting. Therefore, by adjusting the number of cutter arrays on the pressure ring, the pelletizing speeds on hole ring 1 61, hole ring 2 62 and hole ring 3 63 are different, thereby achieving the regulation of the uniformity of pelletized particles.

[0040] As an embodiment of the present invention, refer to Figures 2 to 4, multiple fixing rods 715 are arranged in a circular array on the left side of the disk body 714. The circular array makes the fixing rods 715 evenly distributed on the disk body 714, so that the connection points are evenly distributed, avoiding stress concentration, and thus the pressure ring can be fixed more stably. The fixing rods 715 are inclined to the radial direction of the disk body 714, so that the contact area between itself and the disk body 714 is larger, thereby forming a more stable connection. Through the above arrangement, the connection of the cutter on the disk body 714 is more stable, so as to achieve a more uniform and stable granulation effect. The fixing rods 715 are bolted to the disk body 714, and the connection between the disk body 714 and the knife shaft 72 is inconvenient to disassemble and assemble, and frequent disassembly and assembly will affect the stability of the connection. Therefore, the fixing rods 715 and the disk body 714 are disassembled and connected to facilitate the disassembly and assembly of the pressure ring, thereby facilitating the adjustment of the cutter spacing, so that the granulated particles can ensure good uniformity under a variety of pelletizing environments. The first pressure ring 716, the second pressure ring 717 and the third pressure ring 718 are all welded to the fixing rod 715. The number of fixing rods 715 cannot be too many, otherwise it will affect the discharge of particles. Therefore, the connection area between the fixing rod 715 and the pressure ring is limited, and good stability can be ensured by the non-detachable connection. In this method, six fixing rods 715 are set, so that each fixing rod 715 is tangent to the peripheral surface of the right side small flange of the disk body 714 to enclose a regular hexagon, thereby enhancing the stability of the support.

[0041] As an embodiment of the present invention, refer to Figure 2 After the granulated particles are discharged from the interval of the fixed ring 7161, they will contact the rotating fixed rod 715. In order to avoid the high-speed rotating fixed rod 715 from damaging the particle surface, a resistance reduction surface 7151 is provided on the fixed rod 715 that is not connected to the cutter disc 71. The resistance reduction surface 7151 is arranged on the right side of the fixed rod 715, and the resistance reduction surface 7151 is inclined in the direction of the cutter movement. At the same time, the setting of the resistance reduction surface 7151 inclined in the direction of the cutter movement effectively reduces the resistance of the water flow to the rotation of the disc body 714, saving the energy consumption of the motor 4.

[0042] As an embodiment of the present invention, refer to Figure 5 The pressure ring 716 includes a fixed ring 7161 and a movable ring 7162. The fixed ring 7161 is connected to the left side of the fixed rod 715, and the movable ring 7162 is connected to the left side of the fixed ring 7161. A slide groove 71611 is provided inside the fixed ring 7161. The slide groove 71611 is concentric with the fixed ring 7161. The movable ring 7162 has a circular array of slots 71621, and the number of the slots 71621 is the same as the number of the cutters 711. By setting the number of the slots 71621 on the movable ring 7162, the number of the cutters 711 on the pressure ring can be adjusted, and then the pelletizing speed can be adjusted.

[0043] The clamping groove 71621 runs through the left and right sides of the moving ring 7162. The cutter 711 includes a tail 7111, a blade 7112 and a blade head 7113. The tail 7111 is matched and installed in the sliding groove 71611. The blade head 7113 fits the right side of the template 6. The blade body 7112 connects the tail 7111 and the blade head 7113, and the blade body 7112 is located inside the clamping groove 71621. Through the cooperation of the sliding groove 71611 and the blade head 7113, the cutter is positioned along the axial and radial directions of the fixed ring 7161; through the cooperation of the clamping groove 71621 and the blade body 7112, the cutter is positioned along the circumferential direction of the fixed ring 7161, so that the cutter 711 is fixed on the pressure ring 1 716. The moving ring 7162 and the fixed ring 7161 are detachably connected. In this method, a threaded connection is used to facilitate the disassembly and assembly of the cutter. The second pressing ring 717 and the third pressing ring 718 also have a movable ring 7162 and a fixed ring 7161 , and the second cutting knife 712 and the third cutting knife 713 also include a knife tail 7111 , a knife body 7112 and a knife head 7113 .

[0044] As an embodiment of the present invention, refer to Figure 7 The inner ring of the fixed ring 7161 has a taper, and the major diameter of the inner ring of the fixed ring 7161 is on the right side. A drainage groove 71614 is arranged on the right side surface of the fixed ring 7161. The drainage groove 71614 is distributed on the edge of the fixed ring 7161. The cooling water around the fixed ring 7161 is moved by the drainage groove 71614 to accelerate the flow of the cooling water, thereby causing the water pressure on the right side of the fixed ring 7161 to drop locally, so that the granulated particles are entrained by the water flow and discharged from the interval of the fixed ring 7161. In addition, after being cut, the granulated particles will float due to the buoyancy of the cooling water, which will cause the particles cut by the cutter 1 711 to be cut again by the cutter 2 712 and the cutter 3 713 during the floating process. To avoid this, an extension section 71615 is provided on the fixed ring 7161 on the pressure ring 2 717 and the pressure ring 3 718. The extension section 71615 is arranged on the left side of the fixed ring 7161, and the extension section 71615 has a taper consistent with the inner circle of the fixed ring 7161. At the same time, the extension section 71615 also slows down the circulation of cooling water between the template 6 and the knife disc 71, thereby making the water temperature therebetween higher, so that when the raw material is extruded from the die hole, it will not be cooled too quickly and cannot be spheroidized by virtue of the isotropy of the force in the water.

[0045] As an embodiment of the present invention, refer to Figure 6, the minimum distance from the cutter head 7113 to the fixed ring 7161 is recorded as h, and h is not less than the diameter of the granulated particles. The distance between the fixed ring 7161 on the pressure ring 1 716 and the fixed ring 7161 on the pressure ring 2 717 is greater than the distance between the fixed ring 7161 on the pressure ring 2 717 and the fixed ring 7161 on the hole pressure ring 3 718, and the distance between the fixed ring 7161 on the pressure ring 2 717 and the fixed ring 7161 on the pressure ring 3 718 is not less than the diameter of the granulated particles. Too small a distance is not conducive to the discharge of the granulated particles, and if the h value is less than the diameter of the granulated particles, the cutter will squeeze the particles that have not yet hardened, making the spheroidization of the particles incomplete. In addition, the h value should not be too large, so as to cooperate with the extension section 71615 to better insulate the cooling water between the template 6 and the cutter disc 71, so that the granulated particles can be better spheroidized.

[0046] As an embodiment of the present invention, refer to Figures 7 to 9 A knife inlet 71612 is provided on the slide groove 71611, so that the cutter can be freely disassembled and assembled. Furthermore, the knife inlets 71612 on the pressing ring 1 716, the pressing ring 2 717 and the pressing ring 3 718 are arranged along any radius of the disk body 714, and a closing pin 71613 is installed in the knife inlet 71612, so that multiple knife inlets 71612 can be controlled by one closure, which facilitates the disassembly and assembly of the cutter.

[0047] During disassembly, after removing the connecting module between the fixed ring 7161 and the fixed rod 715 from the disk body 714, first place the module on a horizontal plane with the fixed rod 715 facing downward, then release the connection between the movable ring 7162 and the fixed ring 7161, then remove the closing pin 71613 and take it out from the cutting edge 71612, then rotate the movable ring 7162 to align the slot 71621 with the cutting edge 71612 to take out the cutter, and repeat the rotation process of the movable ring 7162 until all cutters are taken out. During installation, first place the moving ring 7162 on the fixed ring 7161, and align a certain slot 71621 with the cutting edge 71612, then place the tail 7111 of the cutter with the slot 71621 into the cutting edge 71612, and as the moving ring 7162 enters the slide groove 71611, repeat the above process until all the cutters are installed, then insert the closing pin 71613 into the cutting edge 71612 and fix it, and finally fix the moving ring 7162.

[0048] Working principle: after the heating belt is removed, the temperature of the plastic raw material inside the expansion section is not uniform, and the flow of the raw material in each place will also be different. The closer the raw material is to the center of the template 6, the higher the temperature is, and the faster it is extruded. Correspondingly, when the integrated cutter passes through the die holes on the inner and outer rings of the template 6 at the same time, the size of the cut particles will be different. In order to avoid this phenomenon, the present invention considers making the time intervals between adjacent cutters passing through the same die hole different. The closer the die hole is to the outside, the longer the time interval is (correspondingly, the pelletizing speed of the outer ring relative to the inner ring will be reduced), so that the particles in the outer ring have more time to be extruded to obtain larger particles.

[0049] Specifically, the present invention divides the originally integrated cutter into three parts: cutter one 711, cutter two 712 and cutter three 713, and arranges them in a circular array on pressure ring one 716, pressure ring two 717 and pressure ring three 718 respectively. Pressure ring one 716, pressure ring two 717 and pressure ring three 718 are all fixed on the fixed rod 715 and driven by the motor 4 to rotate synchronously. In order to achieve the above-mentioned effect - the cutter closer to the outer circle takes a longer time to pass through the same mold hole, the number of arrays of cutter one 711, cutter two 712 and cutter three 713 is reduced step by step, so that the distance between the cutters is increased step by step.

[0050] The present invention achieves uniformity of granulation particle size by adjusting the number of cutters on the pressure ring. For different working conditions, the specific number of cutters required is obtained through advance design and calculation on the one hand, and obtained through on-site debugging on the other hand, so the number of cutters on the pressure ring should be adjustable, and the adjustment process should be convenient. Therefore, the present invention divides the pressure ring into two parts, a fixed ring 7161 and a movable ring 7162, and makes the two parts detachably connected. While the positioning of the cutter is achieved through the slide groove 71611 of the fixed ring 7161 and the clamping groove 71621 of the movable ring 7162, the number of cutters on the pressure ring can be adjusted by replacing the movable ring 7162 with a different number of clamping grooves 71621.

[0051] Reference Fig. 9The specific disassembly and assembly process of the cutter is as follows: during disassembly, after removing the connection module between the fixed ring 7161 and the fixed rod 715 from the disk body 714, first place the module on a horizontal plane with the fixed rod 715 facing downward, then release the connection between the movable ring 7162 and the fixed ring 7161, then remove the closing pin 71613 and take it out from the knife feed port 71612, then rotate the movable ring 7162 to align the slot 71621 with the knife feed port 71612 to take out the cutter, and repeat the rotation process of the movable ring 7162 until all cutters are taken out. During installation, first place the moving ring 7162 on the fixed ring 7161, and align a certain slot 71621 with the cutting edge 71612, then place the tail 7111 of the cutter with the slot 71621 into the cutting edge 71612, and as the moving ring 7162 enters the slide groove 71611, repeat the above process until all the cutters are installed, then insert the closing pin 71613 into the cutting edge 71612 and fix it, and finally fix the moving ring 7162.

[0052] After the particles are cut, they float up due to the buoyancy of the cooling water. During this process, the particles cut by the cutter 1 711 will be cut again by the cutter 2 712 and the cutter 3 713, thus damaging the surface of the particles. To prevent this phenomenon, an extension section 71615 is provided on the fixed ring 7161, and the extension section 71615 and the fixed ring 7161 have a taper. With the help of the drainage groove 71614, the particles are discharged along the interval of the fixed ring 7161.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A modified plastic extrusion granulator, comprising an extruder (1), a pelletizing chamber (2), a water supply device (3), a motor (4) and a material receiving device (5), wherein the extruder (1) comprises a main body (11) and an expansion section (12), and is characterized in that: The invention also comprises a template (6) and a pelletizing module (7), wherein the template (6) is coaxially connected to the expansion section (12), the template (6) is provided with a hole ring 1 (61), a hole ring 2 (62) and a hole ring 3 (63), the pelletizing module (7) is connected to the left side of the motor (4), and the pelletizing module (7) comprises a knife disc (71), the knife disc (71) is located on the right side of the template (6), and a cutter 1 (711), a cutter 2 (712) and a cutter 3 (713) are arranged in a circular array from the inside to the outside on the left end surface of the knife disc (71), and the cutter 1 (711), the cutter 2 (712) and the cutter 3 (713) are driven by the motor (4) to rotate synchronously and perform differential pelletizing on the hole ring 1 (61), the hole ring 2 (62) and the hole ring 3 (63).

2. A modified plastic extrusion granulator according to claim 1, characterized in that: The pelletizing module (7) further comprises a knife shaft (72) and a pressure plate (73), wherein the right end of the knife shaft (72) is connected to the main shaft of the motor (4), and the pressure plate (73) is nested on the knife shaft (72). The knife disc (71) further comprises a disc body (714), a fixing rod (715), a first pressure ring (716), a second pressure ring (717) and a third pressure ring (718), wherein the disc body (714) is nested on the left end of the knife shaft (72), and a plurality of the fixing rods (715) are connected to the left side of the disc body (714). The pressure ring 1 (716), the pressure ring 2 (717) and the pressure ring 3 (718) are all connected to the left side of the fixing rod (715), and the projections of the three on the right side surface of the template (6) in the left-right direction respectively cover the hole ring 1 (61), the hole ring 2 (62) and the hole ring 3 (63); the cutter 1 (711), the cutter 2 (712) and the cutter 3 (713) are respectively arranged in a circular array on the pressure ring 1 (716), the pressure ring 2 (717) and the pressure ring 3 (718), and the number of the three arrays is different.

3. A modified plastic extrusion granulator according to claim 2, characterized in that: The fixing rod (715) is detachably connected to the disk body (714), and the first pressing ring (716), the second pressing ring (717) and the third pressing ring (718) are all non-detachably connected to the fixing rod (715).

4. A modified plastic extrusion granulator according to claim 3, characterized in that: A plurality of fixing rods (715) are arranged in a circular array on the left side of the disk body (714), and the fixing rods (715) are inclined to the radial direction of the disk body (714).

5. A modified plastic extrusion granulator according to claim 4, characterized in that: A resistance reducing surface (7151) is provided on a portion of the fixed rod (715) not connected to the cutter disc (71). The resistance reducing surface (7151) is arranged on the right side surface of the fixed rod (715), and the resistance reducing surface (7151) is inclined in the direction of movement of the cutter.

6. A modified plastic extrusion granulator according to claim 2, characterized in that: The pressure ring (716) comprises a fixed ring (7161) and a movable ring (7162), wherein the fixed ring (7161) is connected to the left side of the fixed rod (715), and the movable ring (7162) is connected to the left side of the fixed ring (7161). A slide groove (71611) is provided inside the fixed ring (7161), and the slide groove (71611) is concentric with the fixed ring (7161). A circumferential array of slots (71621) is provided on the movable ring (7162), and the number of the slots (71621) is the same as the number of the cutter (711). The slots (71621) run through the left and right sides of the movable ring (7162), and the cutter (711) The invention comprises a knife tail (7111), a knife body (7112) and a knife head (7113), wherein the knife tail (7111) is matched and installed in a slide groove (71611), the knife head (7113) fits the right side of the template (6), the knife body (7112) connects the knife tail (7111) and the knife head (7113), and the knife body (7112) is located inside the clamping groove (71621), the second pressing ring (717) and the third pressing ring (718) also have a moving ring (7162) and a fixed ring (7161), and the second cutting knife (712) and the third cutting knife (713) also comprise a knife tail (7111), a knife body (7112) and a knife head (7113).

7. A modified plastic extrusion granulator according to claim 6, characterized in that: The minimum distance from the cutter head (7113) to the fixed ring (7161) is denoted as h, and h is not less than the diameter of the granulated particles. The spacing between the fixed ring (7161) on the pressure ring one (716) and the fixed ring (7161) on the pressure ring two (717) is greater than the spacing between the fixed ring (7161) on the pressure ring two (717) and the fixed ring (7161) on the hole pressure ring three (718), and the spacing between the fixed ring (7161) on the pressure ring two (717) and the fixed ring (7161) on the pressure ring three (718) is not less than the diameter of the granulated particles.

8. A modified plastic extrusion granulator according to claim 6, characterized in that: The slide groove (71611) is provided with a cutting edge (71612), and the cutting edges (71612) on the pressure ring 1 (716), the pressure ring 2 (717) and the pressure ring 3 (718) are arranged along any radius of the disk body (714), and a closing pin (71613) is installed in the cutting edge (71612).

9. A modified plastic extrusion granulator according to claim 6, characterized in that: The inner ring of the fixed ring (7161) has a taper, and the major diameter of the inner ring of the fixed ring (7161) is on the right side. A drainage groove (71614) is provided on the right side surface of the fixed ring (7161), and the drainage groove (71614) is distributed on the edge of the fixed ring (7161).

10. A modified plastic extrusion granulator according to claim 9, characterized in that: The fixed ring (7161) on the pressure ring two (717) and the pressure ring three (718) has an extension section (71615), and the extension section (71615) is arranged on the left side of the fixed ring (7161), and the extension section (71615) has a taper consistent with the inner ring of the fixed ring (7161).

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