A cooling water deflector for an underwater pellet cutter

Abstract

The utility model provides a kind of cooling water fairing for underwater pelletizer, it is related to polyolefin extrusion granulation field, including fairing body and cooling water guide pipe, both adopt welding mode fixed and internal cavity is connected;Wherein, fairing body is the conical cylinder of two ends open, its big mouth end is towards cutter disc direction, and can cover the flow guide hole area on cutter disc, small mouth end and support fixed connection;The water inlet end of cooling water guide pipe is towards the water inlet of water chamber, and its pipe diameter is less than the water inlet diameter of water chamber, so that cooling water enters from cooling water guide pipe, flows out from big mouth end in the inside of fairing body, then enters between cutter disc and granulating template by flow guide hole, finally is discharged by the water outlet of water chamber.The utility model can shunt cooling water in water chamber, increase the water flow between granulating template and underwater pelletizer, and can effectively block the particle that has been cut back to between granulating template and underwater pelletizer.

Description

Technical Field

[0001] This utility model belongs to the field of polyolefin extrusion granulation, and in particular relates to a cooling water guide cover for an underwater pelletizer. Background Technology

[0002] With the rapid development of industries such as new energy, white goods, and consumer electronics, the market demand for high-performance polyolefin materials is showing a trend of large-scale growth, and higher standards are being set for material strength, weather resistance, and processing performance. In the industrial production of high-performance polyolefin materials, the screw extrusion granulator is a core piece of equipment, undertaking the core processes of material melting, homogenization, and molding. The working principle of this equipment is as follows: after the polyolefin raw material is fed in, it is fully melted and reaches a homogeneous state through the shearing, conveying, and heating action of the screw. The molten material is then pressed into a granulation die, extruded through specific channels on the die, and finally cut at high speed by a matching underwater pelletizer to obtain uniformly sized granular finished products.

[0003] However, in actual production, underwater pelletizers need to maintain high-speed rotation to achieve efficient pelletizing, which creates a localized vacuum area in the tiny gap between the pelletizer and the pelletizing template. When the cooling water used to cool the cut pellets comes into contact with the high-temperature molten material extruded from the pelletizing template, some of the cooling water will rapidly vaporize in the vacuum area, forming tiny bubbles. Subsequently, low-temperature cooling water will continuously fill this vacuum area, causing the formed bubbles to burst instantly, resulting in a sharp fluctuation in local pressure and thus cavitation. Cavitation continuously erodes the surface structure of the pelletizing template, leading to template wear and channel deformation. This not only significantly shortens the service life of the pelletizing template but also increases equipment maintenance costs and downtime frequency, affecting the continuity and stability of production.

[0004] Furthermore, the high-speed rotation of the underwater pelletizer's cutter head creates an irregular turbulent flow field in the gap between it and the pelletizing template. This turbulent flow disrupts the stable flow of cooling water in this area. Under this turbulence, some of the qualified particles that have already been cut will be drawn back into the gap between the pelletizing template and the pelletizer through the guide holes on the cutter head. The drawn-back particles will re-adhere and mix with the newly extruded high-temperature molten material, ultimately leading to various quality defects after cutting, such as sticky particles (particles adhering to each other), particles with tails (particles with irregular extensions at the ends), and debris (tiny broken particles). This not only reduces the finished product qualification rate but may also clog the template channels, further affecting the continuity and stability of production. Utility Model Content

[0005] This invention provides a cooling water guide cover for an underwater pelletizer, which can divert the cooling water in the water chamber, increase the water flow between the pelletizing template and the underwater pelletizer, and effectively prevent the cut particles from being sucked back between the pelletizing template and the underwater pelletizer.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a cooling water guide shroud for an underwater pelletizer. The underwater pelletizer has a water chamber, and an inlet located below and an outlet located above the water chamber. A support is provided inside the water chamber, and the guide shroud is fixed by the support. The guide shroud includes a guide shroud body and a cooling water guide pipe, which are fixed by welding and have interconnected internal cavities. The guide shroud body is a conical cylinder with open ends. Its large end faces the direction of the cutter head and can cover the guide hole area on the cutter head. The small end is fixedly connected to the support. The inlet end of the cooling water guide pipe faces the inlet of the water chamber, and its pipe diameter is smaller than the inlet diameter of the water chamber, so that cooling water enters from the cooling water guide pipe, flows out from the large end inside the guide shroud body, and then enters between the cutter head and the pelletizing template through the guide holes, and finally exits from the outlet of the water chamber.

[0007] Furthermore, the bracket is annular, with bolt connection holes evenly distributed along the circumference on its upper end face, and an annular flange edge is provided at the small opening end of the shroud body, with corresponding bolt connection holes on the flange edge. The bracket and the shroud body are fixed through the bolt connection holes.

[0008] Furthermore, the axis of the cooling water guide pipe is offset relative to the center of the side wall of the guide shroud body, forming an eccentric connection structure.

[0009] Furthermore, the gap between the plane of the large opening end of the fairing body and the plane of the cutter head is 0.5-2mm.

[0010] Furthermore, the guide shield body is fitted around the power input shaft of the cutter head, but does not contact the power input shaft.

[0011] Furthermore, both the fairing body and the cooling water guide pipe are made of wear-resistant steel to resist surface pitting caused by particle impact and scratching.

[0012] Based on the above technical solution, the beneficial effects of this utility model are as follows: 1. In this utility model, the guide shroud body, through a connected cooling water guide pipe, diverts and guides the cooling water entering the water chamber. Most of the cooling water, guided by the guide shroud, flows precisely to the pelletizing template through the guide holes on the underwater pelletizer cutter disc. Simultaneously, the open conical cylindrical structure design at both ends of the guide shroud body increases the water pressure flowing from the cutter disc to the pelletizing template, effectively enhancing the cooling effect and water flow stability in the pelletizing template area. This effectively reduces surface erosion and channel deformation of the pelletizing template, significantly extending its service life and reducing equipment maintenance costs and unplanned downtime.

[0013] 2. In this utility model, the guide hood body can effectively isolate the cut particles in the water chamber from the granulation template area, preventing the cut particles from entering the tiny gap between the granulation template and the underwater pelletizer through the cutter disc guide hole, avoiding the adhesion between the cut particles and the uncut material during the pelletizing process, thus preventing quality problems such as sticky particles, particles with tails, and debris, and greatly improving the uniformity and pass rate of the finished particles.

[0014] 3. In this utility model, a gap is reserved between the guide shroud and the underwater pelletizer cutter disc. This gap allows a small amount of cooling water in the guide shroud to flow directly into the water chamber. The continuously flowing micro-volume cooling water flushes the gap area between the guide shroud and the cutter disc in real time, preventing the accumulation of cut particles in this area. This solves the problems of pipe blockage and equipment jamming caused by material accumulation in the water chamber, ensuring that the entire pelletizing system can operate stably for a long time. Attached Figure Description

[0015] Figure 1 This is a partial structural diagram of an underwater pelletizer. To show the internal structure, the end cap on one side of the water chamber has been removed. Figure 2 for Figure 1 Sectional view along direction AA; Figure 3 This is a schematic diagram of the overall structure of this utility model; Figure 4 A schematic diagram of the particle state without a deflector installed; Figure 5 This is a schematic diagram of the particle state after the deflector is installed.

[0016] The markings in the diagram are: 1. Underwater pelletizer, 2. Water chamber, 201. Water inlet, 3. Granulation template, 4. Power input shaft, 5. Socket head screw, 6. Flow guide, 7. Flow guide body, 8. Cooling water guide pipe, 9. Cutter disc, 10. Flow guide hole, 11. Support, 12. Particle. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0019] like Figure 1-3 As shown, the underwater pelletizer 1 is provided with a water chamber 2, and a water inlet 201 located below the water chamber 2 and a water outlet located above the water chamber 2. The water chamber 2 is provided with a circular support 11, and bolt connection holes are evenly opened on its upper end face along the circumferential direction. The guide shroud 6 can be fixed through the support 11.

[0020] The flow guide 6 includes a flow guide body 7 and a cooling water guide pipe 8, which are fixed by welding and have interconnected internal cavities. The flow guide body 7 is a conical cylinder with open ends. Its larger end faces the cutter head 9 and covers the area of ​​the flow guide hole 10 on the cutter head 9. This design not only increases the water pressure of the cooling water in this area but also accelerates the flow of the cooling water, thereby reducing cavitation and extending the service life of the granulation template 3. The smaller end extends radially inward to form an annular flange edge with bolt connection holes. The flow guide body 7 is secured by passing hexagonal head screws 5 through the bolt connection holes at its smaller end and aligning them with the bolt connection holes at the corresponding positions on the bracket 11, thus achieving a detachable and fixed connection between the flow guide 6 and the bracket 11.

[0021] The inlet end of the cooling water guide pipe 8 faces the inlet 201 of the water chamber 2, and its pipe diameter is smaller than the inlet 201 of the water chamber 2, so that the cooling water enters from the cooling water guide pipe 8, flows out from the large end through the inside of the guide shroud body 7, and then enters between the cutter head 9 and the granulation template 3 through the guide hole 10, and finally is discharged from the outlet of the water chamber.

[0022] In addition, both the shield body 7 and the cooling water guide pipe 8 are made of wear-resistant steel, which can effectively resist surface pitting caused by the impact and scratching of particles 12.

[0023] In specific implementation, the cooling water guide pipe 8 is eccentrically welded to the side wall of the guide shroud body 7, that is, the axis of the cooling water guide pipe 8 is offset relative to the center of the side wall of the guide shroud body 7; the cutter disc 9 is placed between the end face of the granulation template 3 and the large opening end of the guide shroud body 7 via the power input shaft 4, and the axes of the three are collinear. The gap between the plane where the cutter disc 9 is located and the plane where the large opening end of the guide shroud body 7 is located is 0.5-2mm. This gap allows a small portion of the cooling water in the guide shroud 6 to flow through, which can effectively solve the problem that the cooling water flow rate in other positions in the water chamber 2 is reduced due to the diversion of most of the cooling water by the cooling water guide pipe 8, and the particles 12 accumulate between the guide shroud 6 and the underwater pelletizer 1. Moreover, this gap can be adjusted appropriately according to the particles 12; the guide shroud body 7 is sleeved around the power input shaft 4 of the cutter disc 9 and has no contact with the power input shaft 4, which is used to ensure that the guide shroud body 7 does not rotate with the rotation of the power input shaft 4.

[0024] pass Figure 4 and Figure 5 The difference in particle 12 distribution before and after the installation of the deflector 6 can be visually observed. This is especially true when the deflector 6 is not installed (corresponding to...). Figure 4 The pre-cut particles 12 inside the underwater pelletizer 1 are in a completely disordered and freely dispersed state, without clear barriers. Particles 12 can flow freely within the water chamber 2 and easily enter the space between the cutter disc 9 and the pelletizing template 3 through the guide holes 10 on the cutter disc 9. This can cause issues such as stuck particles, particles with tails, and debris during pelleting, affecting the uniformity and yield of the finished particles, and potentially causing pipe blockages and equipment jamming. However, after the guide shroud 6 is installed (corresponding to...), Figure 5 Based on the closed cavity structure formed by welding the guide shroud body 7 and the cooling water guide pipe 8, combined with the physical barrier effect of the guide shroud 6 itself, particles 12 are effectively intercepted outside the area where the guide shroud 6 is located, and cannot enter the interior of this area, nor can they enter between the cutter head 9 and the granulation template 3 through the guide hole 10. This not only ensures the smooth flow of cooling water inside the guide shroud 6, but also provides a clean and interference-free working environment for the stable operation of core components such as the granulation template 3 and the cutter head 9, avoiding various problems caused by the interference of particles 12.

[0025] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A cooling water guide shroud for an underwater pelletizer, the underwater pelletizer (1) having a water chamber (2), and a water inlet (201) located below and an outlet located above the water chamber (2), characterized in that: The water chamber (2) is equipped with a bracket (11) to fix the flow guide (6); The flow guide (6) includes the flow guide body (7) and the cooling water guide pipe (8), which are fixed by welding and have interconnected internal cavities; wherein, the flow guide body (7) is a conical cylinder with open ends, the large end of which faces the direction of the cutter head (9) and can cover the flow guide hole (10) area on the cutter head (9), and the small end is fixedly connected to the bracket (11); The inlet end of the cooling water guide pipe (8) faces the inlet (201) of the water chamber (2), and its pipe diameter is smaller than the inlet (201) diameter of the water chamber (2), so that the cooling water enters from the cooling water guide pipe (8), flows out from the large end through the inside of the guide shroud body (7), and then enters between the cutter disc (9) and the granulation template (3) through the guide hole (10), and finally is discharged from the outlet of the water chamber (2).

2. A cooling water guide shroud for an underwater pelletizer according to claim 1, characterized in that: The bracket (11) is annular, and bolt connection holes are evenly distributed along the circumference on its upper end face. The small end of the shroud body (7) is provided with an annular flange edge, and bolt connection holes are provided on the flange edge accordingly. The bracket (11) and the shroud body (7) are fixed by bolt connection holes.

3. A cooling water guide shroud for an underwater pelletizer according to claim 1, characterized in that: The axis of the cooling water guide pipe (8) is offset relative to the center of the side wall of the guide body (7), forming an eccentric connection structure.

4. A cooling water guide shroud for an underwater pelletizer according to claim 1, characterized in that: The gap between the plane of the large opening end of the fairing body (7) and the plane of the cutter head (9) is 0.5-2mm.

5. A cooling water guide shroud for an underwater pelletizer according to claim 1, characterized in that: The guide shield body (7) is sleeved around the power input shaft (4) of the cutter head (9) and has no contact with the power input shaft (4).

6. A cooling water guide shroud for an underwater pelletizer according to claim 1, characterized in that: Both the shroud body (7) and the cooling water guide pipe (8) are made of wear-resistant steel to resist surface pitting caused by particle (12) impact and scratching.

Images