Ultra-large filter-mixer screen changing device

Abstract

A super-large screen changing device for filtering and mixing, characterized in that it comprises an outer shell composed of an inlet plate, an outlet plate and pads clamped between the upper and lower ends of the inlet plate and the outlet plate, a slide plate type filter unit installed in a slideway composed of the outlet plate, the inlet plate and the upper and lower pads, a power mechanism for driving the slide plate type filter unit to reciprocate along the slideway is connected to one side of the slide plate type filter unit through a connecting block; the slide plate type filter unit is provided with a material channel and an integrated porous plate, and a filter screen is provided on the feed side of the integrated porous plate; a petal-type dynamic sealing disk with a hollow structure in the middle part and a sealing auxiliary spring are provided between the mating surfaces of the inlet plate and the slide plate type filter unit, and the feed port and the mixing channel of the inlet plate are of a honeycomb structure; a petal-type static sealing disk with a hollow structure in the middle part is provided between the mating surfaces of the outlet plate and the slide plate type filter unit, and the discharge port and the mixing channel of the inlet plate are of a honeycomb structure.

Description

Technical Field

[0001] The invention relates to a filtering device used before synthetic resin (polymer) pelletizing in petrochemical industry or before large plastic modification and pelletizing, in particular to an ultra-large special screen changing device with mixing function. Background Art

[0002] The main function of the screen changer is to filter impurities, and secondly to increase the back pressure in front of the pelletizing (granulating) machine head, which helps the devolatilizer to completely remove volatiles, making the material mixing or plasticizing more uniform, and the produced plastic particles denser and brighter. Similarly, in the petrochemical industry, impurities will be generated during the polymerization process of polymer materials or large-scale plastic modification and granulation, so the materials need to be filtered before pelletizing (granulating), and a screen changer should be installed.

[0003] The large-scale screen changers in the prior art are designed with the feed port as large as the screen diameter. The higher the output, the larger the filtration area. Although the screen area of ​​the screen changer is large, the effective flow rate is small, because the integrated porous plate and the solid part of the screen occupy most of the cross-sectional area. The pipeline connected to the screen changer is also designed based on the effective flow rate. Therefore, the material entering from the inlet plate of the screen changer is prone to stagnation in the main body of the screen changer, which in turn produces the consequences of stagnation.

[0004] More specifically, the screen changing device in the prior art mainly has the following shortcomings:

[0005] 1. Because the output of this industry is very high, with a single machine producing more than ten tons per hour, the filter area of ​​the screen changing device is large, and the integrated porous plate is prone to deformation due to lack of a supporting mechanism.

[0006] 2. The industry filters polymer melts, which have high viscosity and poor fluidity. The sealing system of the screen changer is defective and prone to leakage when the melt pressure is high.

[0007] 3. Because the flow rate is large and the filter screen has resistance, the filtration area and the diameter of the channel are also large, but the flow channel diameter of the melt tube is small, and the cross-sectional area of ​​the two differs by 3-4 times. This will inevitably cause the melt in front of the screen to stagnate or be retained, the material is prone to overheating and degradation, and the color of the finished particles is yellow and dark, which reduces the quality of the material.

[0008] 4. Because of the large flow rate and the large channel of the screen changer, the material temperature at the core of the melt is not uniform with the temperature outside, which affects the flow of the material. Both the melt pipe and the screen changer are heated on the outside, and it takes time for the heat to be transferred to the center. If the machine is shut down for maintenance and restarted, the solidified large block of material needs to be preheated for a long time in advance. If the hard block at the core is not melted and forced out, a major accident will occur. Summary of the invention

[0009] The purpose of the present invention is to provide a super-large filter-mixer integrated screen changing device with a more reasonable structure in order to address the deficiencies in the above-mentioned prior art.

[0010] The purpose of the present invention can be achieved by the following measures:

[0011] The filtering and mixing integrated super-large screen changing device of the present invention comprises an outer shell composed of an inlet plate, an outlet plate and a padding strip clamped between the upper and lower ends of the inlet plate and the outlet plate, a slide plate type filter unit installed in a slideway composed of the outlet plate, the inlet plate and the upper and lower padding strips, and a power mechanism for driving the slide plate type filter unit to reciprocate along the slideway is connected to one side of the slide plate type filter unit through a connecting block; the slide plate type filter unit is provided with a material channel and an integrated porous plate, and a filter screen is provided on the feed side of the integrated porous plate; a petal-type dynamic sealing disk with a hollow structure in the middle part and a sealing auxiliary spring are provided between the mating surfaces of the inlet plate and the slide plate type filter unit, and the feed port and the mixing channel of the inlet plate are of a honeycomb structure; a petal-type static sealing disk with a hollow structure in the middle part is provided between the mating surfaces of the outlet plate and the slide plate type filter unit, and the discharge port and the mixing channel of the outlet plate are of a honeycomb structure.

[0012] The right side end of the skateboard type filter unit in the present invention is combined with a hydraulic cylinder used to drive the skateboard type filter unit to reciprocate along the slideway through a connecting block; the hydraulic cylinder is connected to the right side end of the shell through an upper and lower double-headed positioning support rod and a cylinder mounting plate connected to the right end of the upper and lower double-headed positioning support rod.

[0013] The petal-type dynamic sealing disc and the petal-type static sealing disc are respectively embedded in the grooves processed on one side of the matching surface of the inlet plate, the outlet plate and the slide plate type filter unit.

[0014] The present invention provides six supporting points arranged in a ring shape at the middle part of the integrated porous plate. After being subjected to force, all of them act on the supporting ring on the petal-type static sealing disk, and the supporting ring of the static sealing disk acts on the honeycomb structure supporting structure of the outlet plate of the screen changing device. One ring is linked to another, and the overall force is integrated. The force of the integrated porous plate is borne by the whole device, which is safe, reliable and durable.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The design of the honeycomb-structured inlet and outlet and the mixing channel described in the present invention effectively solves the problem in the prior art that the material entering the inlet plate of the screen changer is prone to stagnation in the main body of the screen changer, thereby causing the consequences of stagnation.

[0017] Specifically, the main functions of the inlet and outlet and mixing channel of the honeycomb structure designed by the present invention are as follows: a. Effectively fill the large-diameter flow channel to avoid material stagnation, degradation and discoloration; b. Increase the flow resistance in the middle part, force the surrounding material flow rate to speed up, and avoid material retention at the wall in the circumferential direction, because the polymer melt has a tube wall effect, that is, the middle flow rate is greater than the tube wall; c. Dividing the large cavity of the feed port into several small cavities changes the rheological behavior of the material, which is beneficial to the dispersion, mixing and homogenization of the material and processing aids, especially when combined with other components, the effect is more obvious; d. It is beneficial to the heat transfer of the material, because the honeycomb body and the inlet and outlet plates are an integrated structure, whether it is the introduction of external heat or the dissipation of internal heat, the efficiency is greatly improved, especially when the polymerization or modification device is restarted after overhaul, it is beneficial to the rapid melting of large pieces of material. e. This structure increases the rigidity and strength of the screen changer. The flow channel cavity of the traditional large-scale screen changer is large, poor in integrity, and easy to deform. The honeycomb structure designed by the present invention is equivalent to playing the role of reinforcing ribs, and its practicality is greatly increased.

[0018] 2. The design of the petal-type dynamic sealing disc described in the present invention can effectively solve the following shortcomings caused by the use of annular flexible seals in large-scale screen changers in the prior art: First, the melt pressure of the polymer cannot be effectively utilized, resulting in uneven and insufficient sealing force, causing leakage of the material melt; second, the large volume in the middle of the sealing ring aggravates the stagnation of the material, so the material entering from the screen changer inlet plate is more likely to be retained in the screen changer body, reducing the quality of the material.

[0019] More specifically, the design functions of the petal-type dynamic sealing disk of the present invention are as follows: a. The newly designed sealing disk has a small effective volume to avoid material stagnation; b. The flow resistance of the material in the disk is adjusted to make the flow rate of the peripheral material as consistent as possible to avoid material retention at the wall in the circumferential direction. At the same time, because the middle "petal" of the dynamic sealing disk is pushed forward by the melt, the dynamic sealing disk is forced to fit with the slide of the filter unit, so that the flexible sealing space is evenly stressed and the uncertainty of the seal is eliminated; c. The cavity in the disk is divided into several small cavities, which changes the rheological behavior of the material, which is beneficial to the mixing and homogenization of the material and the processing aid, especially when combined with other components, the effect is more obvious, which is equivalent to a static mixer; d. It is beneficial to the heat transfer of the material, because the sealing disk is embedded in the inlet plate, both the external heat introduction and the internal heat dissipation efficiency are greatly improved, especially when the polymerization or modification device is restarted after overhaul, it is beneficial to the rapid melting of large pieces of material; e. This structure increases the rigidity of the dynamic sealing disk. The dynamic sealing ring used in traditional large-scale screen changers is pure annular and easy to warp and deform. The "petal-shaped" design is equivalent to strengthening the middle filling, which makes the dynamic sealing disc extremely stable in size and extremely long in service life.

[0020] 3. The design of the petal-shaped static sealing disc described in the present invention can effectively solve the following shortcomings caused by the use of annular flexible seals in large-scale screen changers in the prior art: First, it cannot be supported in coordination with the screen changer to avoid deformation of the integrated porous plate under high pressure difference, which may damage the slideway and sealing mechanism at the least, or even damage the integrated porous plate and cause the screen changer to be scrapped. Second, the large volume in the middle of the ring aggravates the stagnation of the material, so the material entering from the outlet of the integrated porous plate is more likely to be retained in the main body of the screen changer, and even degraded and aged.

[0021] More specifically, the petal-shaped static sealing disk of the present invention has the following design functions: a. It is designed as a sealing disk structure with a small internal volume to avoid material stagnation and allow the material to flow away quickly after passing through the screen; b. Both sides of the disk are designed with annular supporting surfaces. When the one-piece porous plate is slightly deformed by the high pressure difference, its supporting point is in close contact with the annular supporting surface of the static sealing disk. The disk assists the deformed one-piece porous plate to bear force together. When the one-piece porous plate is subjected to a further increase in the high pressure difference, the combination formed by the one-piece porous plate and the supported "petal-shaped" static sealing disk is also deformed. The supporting annular surface on the other side of the static sealing disk will naturally act on the honeycomb structure support structure of the outlet plate of the main body of the screen changing device. In this way, the screen changing device is c. Dividing the cavity inside the disk into several small cavities changes the rheological behavior of the material, which is beneficial to the mixing and homogenization of the material and processing aids, especially when combined with other components, the effect is more obvious, which is equivalent to a static mixer; d. It is beneficial to the heat transfer of the material, because the static sealing disk is embedded in the outlet plate, and the efficiency of both the introduction of external heat and the dissipation of internal heat is greatly improved, especially when the polymerization or modification device is restarted after overhaul, which is beneficial to the rapid melting of large blocks of material; e. This structure increases the rigidity of the static sealing disk, and the design of the "petal-type" static sealing disk with support is equivalent to strengthening the middle filling, which makes the sealing disk have excellent dimensional stability and ultra-long service life.

[0022] 4. The present invention provides six supporting points arranged in a ring shape in the middle of the integrated porous plate, forming a slide-type filter unit with supporting points. This effectively solves the following shortcomings existing in the prior art, namely, impurities will be left behind when the polymer melt passes through the filter unit. As the impurities accumulate, the flow resistance becomes larger, the melt pressure increases, and the pressure difference before and after the filter unit becomes larger and larger. The force borne by the integrated porous plate will increase proportionally. The integrated porous plate of a large screen changer has a larger area and bears greater force. In this case, the integrated porous plate is often deformed or broken, with serious consequences.

[0023] More specifically, the present invention provides six supporting points arranged in a ring shape in the middle part of the integrated porous plate. After being subjected to force, all of them act on the supporting ring on the petal-type static sealing disk, and the supporting ring of the static sealing disk acts on the honeycomb structure supporting structure of the outlet plate of the screen changing device. One ring is linked to another, and the overall force is integrated. The force of the integrated porous plate is borne by the entire device, which is safe, reliable and durable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural principle diagram of the present invention in working state.

[0025] Figure 2 yes Figure 1 AA section view.

[0026] Figure 3 yes Figure 1 BB cross-sectional view.

[0027] Figure 4 It is a structural principle diagram of the present invention in a screen changing state.

[0028] Figure 5 yes Figure 4 AA section view.

[0029] Figure 6 yes Figure 4 BB cross-sectional view.

[0030] Serial numbers in the figure: 1 is a hydraulic cylinder, 2 is a connecting block, 3 is a double-headed positioning support rod, 4 is a petal-type static sealing disc, 5 is a slide plate type filter unit, 6 is a gasket, 7 is an inlet plate, 8 is a flexible sealing space, 9 is an integrated porous plate, 10 is a feed port and a mixing channel, 11 is a honeycomb structure at the feed port and the mixing channel, 12 is a filter unit feed port, 13 is a filter screen, 14 is a petal-type dynamic sealing disc, 15 is a sealing auxiliary spring, 16 is an outlet plate, 18 is a discharge port and a mixing channel, 19 is a honeycomb structure at the discharge port and the mixing channel, 20 is a supporting point of the integrated porous plate, 21 is a supporting ring of the petal-type static sealing disc, 22 is an integrated porous plate discharge port, and 23 is a hot kerosene channel. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with embodiments (attached drawings):

[0032] The filtering and mixing integrated super-large screen changing device of the present invention comprises an outer shell composed of an inlet plate 7, an outlet plate 16 and a pad 6 clamped between the upper and lower ends of the inlet plate and the outlet plate, a slide plate type filter unit 5 installed in a slideway composed of the outlet plate, the inlet plate and the upper and lower pads, and a power mechanism for driving the slide plate type filter unit to reciprocate along the slideway is connected to one side of the slide plate type filter unit through a connecting block; the slide plate type filter unit is provided with a material channel and an integrated porous plate 9, and a filter screen 13 is provided on the feed side of the integrated porous plate; a petal-type dynamic sealing disk 14 with a hollow structure in the middle part and a sealing auxiliary spring 15 are provided between the mating surface of the inlet plate 7 and the slide plate type filter unit, and the feed port and the mixing channel 10 of the inlet plate are in a honeycomb structure 11; a petal-type static sealing disk 4 with a hollow structure in the middle part is provided between the mating surface of the outlet plate 16 and the slide plate type filter unit, and the outlet port and the mixing channel 18 of the outlet plate are in a honeycomb structure 19.

[0033] The right side end of the skateboard filter unit 5 described in the present invention is combined with a hydraulic cylinder 1 for driving the skateboard filter unit to reciprocate along the slideway through a connecting block 7; the hydraulic cylinder is connected to the right side end of the outer shell through an upper and lower double-headed positioning support rod 3 and a cylinder mounting plate connected to the right end of the upper and lower double-headed positioning support rod.

[0034] The petal-shaped dynamic sealing disc 14 and the petal-shaped static sealing disc 4 are respectively embedded in the grooves processed on one side of the matching surface of the inlet plate 16, the outlet plate 7 and the slide plate type filter unit.

[0035] The present invention provides six support points 20 arranged in a ring shape at the middle part of the integrated porous plate 9. After being subjected to force, all of them act on the support ring 21 on the petal-type static sealing disk. The support ring 21 of the petal-type static sealing disk acts on the honeycomb structure support structure of the outlet plate of the screen changing device. One ring is linked to another, and the overall force is integrated. The force of the integrated porous plate is borne by the entire device, which is safe, reliable and durable.

[0036] The petal-type dynamic sealing disc, petal-type static sealing disc structure, honeycomb structure at the inlet and outlet, and skateboard-type filter unit of the sealing system of the present invention are scientifically and rationally combined to form an organic whole. On the premise of completing melt filtration, the following functions are highlighted: 1. The new structure makes the sealing system more evenly stressed, more stable and reliable, and ensures no leakage under high output and high pressure. 2. The superimposed support mechanism ensures the normal operation of the integrated porous plate. 3. A simple and practical static mixer is formed, which is equipped with a mixing guide grid. The rheological behavior of the material changes continuously during this process, which is beneficial to the mixing, homogenization and uniform dispersion of processing aids or pigments of the material. 4. Heat complementarity, the material temperature can be quickly transferred to the device body, and the heat of the device body can also fully heat the material to facilitate flow. 5. The combined structure has good stability. In addition to increasing the rigidity of the body, it also protects the screen changing device.

Claims

1. A super-large filter-mixer integrated screen changing device, characterized in that: It includes an outer shell composed of an inlet plate, an outlet plate and pads clamped between the upper and lower ends of the inlet plate and the outlet plate, a slide plate type filter unit installed in a slideway composed of the outlet plate, the inlet plate and the upper and lower pads, and a power mechanism for driving the slide plate type filter unit to reciprocate along the slideway is connected to one side of the slide plate type filter unit through a connecting block; the slide plate type filter unit is provided with a material channel and an integrated porous plate, the feed side of the integrated porous plate is provided with a filter sheet, and six supporting points arranged in a ring are provided in the middle part of the integrated porous plate, and after being subjected to force, they all act on the supporting ring on the petal-type static sealing disk, and the supporting ring of the static sealing disk acts on the honeycomb structure of the outlet plate of the screen changing device On the supporting structure; a petal-shaped dynamic sealing disk with a hollow structure in the middle part and a sealing auxiliary spring are arranged between the mating surfaces of the inlet plate and the skateboard-type filter unit, and the feed port and the mixing channel of the inlet plate are of a honeycomb structure; a petal-shaped static sealing disk with a hollow structure in the middle part is arranged between the mating surfaces of the outlet plate and the skateboard-type filter unit, and the discharge port and the mixing channel of the outlet plate are of a honeycomb structure; the right side end of the skateboard-type filter unit is combined with a hydraulic cylinder for driving the skateboard-type filter unit to reciprocate along the slideway through a connecting block; the hydraulic cylinder is connected to the right side end of the outer shell through an upper and lower double-head positioning support rod and a cylinder mounting plate connected to the right end of the upper and lower double-head positioning support rod.

2. The ultra-large filter-mixer integrated screen changing device according to claim 1, characterized in that: The petal-type dynamic sealing disc and the petal-type static sealing disc are respectively embedded in the grooves processed on one side of the matching surface of the inlet plate, the outlet plate and the slide plate type filter unit.

Images