CN108295531B - Filtration system - Google Patents
Filtration system Download PDFInfo
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- CN108295531B CN108295531B CN201810338944.8A CN201810338944A CN108295531B CN 108295531 B CN108295531 B CN 108295531B CN 201810338944 A CN201810338944 A CN 201810338944A CN 108295531 B CN108295531 B CN 108295531B
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- filter
- melt
- backflushing
- shaft
- primary
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- 238000001914 filtration Methods 0.000 title claims abstract description 84
- 239000000155 melt Substances 0.000 claims abstract description 146
- 239000007788 liquid Substances 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 21
- 230000008569 process Effects 0.000 claims abstract description 19
- 230000004907 flux Effects 0.000 claims abstract description 14
- 239000012535 impurity Substances 0.000 claims abstract description 14
- 230000001172 regenerating effect Effects 0.000 claims abstract description 4
- 238000011010 flushing procedure Methods 0.000 claims description 43
- 230000001276 controlling effect Effects 0.000 claims description 6
- 238000007599 discharging Methods 0.000 claims description 6
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 238000011001 backwashing Methods 0.000 abstract 2
- 229920000728 polyester Polymers 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 230000009471 action Effects 0.000 description 5
- 238000004140 cleaning Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000004043 dyeing Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
- B01D29/05—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements supported
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
- B01D29/13—Supported filter elements
- B01D29/15—Supported filter elements arranged for inward flow filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
- B01D29/52—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
- B01D29/56—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in series connection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/62—Regenerating the filter material in the filter
- B01D29/66—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps
- B01D29/68—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps with backwash arms, shoes or nozzles
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Filtration Of Liquid (AREA)
Abstract
The invention discloses a filtering system which is used for regenerating melt with high temperature and impurities and at least comprises a booster pump, a primary filter and a secondary filter which are connected in sequence; the first-stage filter is an automatic melt backflushing filter; the secondary filter is a filter element type melt filter; the control unit is respectively connected with two pressure sensors positioned at two sides of the primary filter, a pressure sensor positioned at the liquid outlet of the secondary filter, a booster pump, the primary filter and the secondary filter. The invention also discloses an operation process of the filtering system. According to the invention, the filter screen of the primary filter is automatically washed, when the pressure difference between the melt outlet and the melt inlet of the primary filter is excessive, a back washing process is automatically started, and the position and the moving distance of the back washing shaft of the filter of the primary filter are accurately controlled; the circuit structural design is reasonable, the pertinence of the high-temperature melt filtration is high, the flux of the normal melt is large during backflushing, the filtration period is long, frequent replacement of the filter is avoided, the filtration is stable, and the filtration efficiency is high.
Description
Technical Field
The invention belongs to the field of filtering equipment, and particularly relates to a filtering system suitable for high-temperature melt.
Background
At present, the filtering of materials is generally carried out in a single-filter filtering mode, the pertinency is low, the filtering effect is poor, and impurities such as gel formed at high temperature in the chemical reaction process, carbonization caused by long-term heat history and the like need to be removed in the PET thermoplastic polyester production process, so that the filtering process is often involved. The original polyester has short heat history and low impurity content, the technical scheme that a candle filter is arranged before final polycondensation is adopted, the regenerated polyester is produced by taking bottle flakes, waste silk and waste textiles as raw materials, the sources and the components are complex, the impurity content is high, the components such as spinning oil, printing and dyeing auxiliary and the like in the raw materials are easy to degrade, carbonize and generate gel, and if primary filtration is adopted, the service cycle of the filter is extremely short and the filter is replaced frequently, so that the production of the regenerated polyester needs to be designed with multi-stage filtration.
On the other hand, because of high impurity content, the regenerated polyester production process mostly adopts a filter capable of being back-flushed on line, and when the filter is blocked, the filter can be back-flushed, and meanwhile, the normal conveying process is uninterrupted. However, when a conventional backflushing filter backflushes, 25% of the melt flux is used for backflushing, and only 75% of the melt can be normally transported.
Therefore, the two-stage filter is arranged, the filtering precision is sequentially improved, the filtering effect can be improved, the service life of the filter is prolonged, and the influence of backflushing on the normal melt conveying efficiency is reduced.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a filtering system which has high pertinence, large flux, high filtering efficiency, good filtering effect and long service life of a filter.
The technical scheme adopted for solving the technical problems is as follows: a filtering system is used for regenerating melt with high temperature and high impurity content and at least comprises a booster pump, a primary filter and a secondary filter which are connected in sequence;
the primary filter is an automatic melt backflushing filter and at least comprises a cylindrical barrel and a central control system, wherein a filter backflushing shaft, a filter disc, a filter screen and a supporting framework are arranged in the center of the barrel; the bottom of the cylinder body is provided with a melt inlet, the upper part of the cylinder body is provided with a melt outlet, and pressure sensors are arranged at the melt inlet and the melt outlet; a plurality of symmetrical transverse backflushing channels are arranged on the backflushing shaft of the filter; the supporting framework forms a plurality of S-shaped melt flow passages; the transverse recoil channels and the melt flow channels are mutually staggered and communicated one by one;
the secondary filter is a filter element type melt filter, the filtering precision of the secondary filter is greater than that of the primary filter, the secondary filter comprises a hollow cover plate which is vertically symmetrical and a filter element column which is arranged in the middle, a round melt inlet is formed in the side face of the lower cover plate, a round melt outlet is formed in the side face of the upper cover plate, and the filter element column consists of a hollow shell, a filter rod which is arranged in the shell and a filter medium which surrounds the filter rod.
The control unit is respectively connected with two pressure sensors positioned at two sides of the primary filter, a pressure sensor positioned at the liquid outlet of the secondary filter, a booster pump, the primary filter and the secondary filter, and when the pressure difference between the liquid inlet and the liquid outlet of the primary filter reaches a set value, the control unit controls the primary filter to perform back flushing, and the booster pump is regulated to increase flux; when the pressure difference of two pressure sensors at the liquid inlet and the liquid outlet of the secondary filter reaches a set value, the control unit adjusts the secondary filter to perform back flushing; the control unit is also used for controlling the primary filter and the secondary filter to start the back flushing program at the same time.
The central position of the primary filter is provided with the filter backflushing shaft, and the plurality of transverse backflushing channels on the filter backflushing shaft are controlled to be communicated with the melt flow channel or not through the up-down movement of the filter backflushing shaft, so that the automatic flushing of the filter screen of the primary filter is realized, the cleaning efficiency is high, the cleaning effect is good, the filtration and the cleaning can be in seamless butt joint, and a plurality of disassembly and assembly processes are saved; the arrangement of the central control system realizes the accurate control of the up-and-down movement of the filter backflushing shaft, is convenient for the alignment of the transverse backflushing channel and the melt flow channel, and is also convenient for controlling the up-movement distance of the filter backflushing shaft; the pressure sensors of the melt inlet and the melt outlet are arranged, so that the impurity accumulation condition on the filter screen in the filter is conveniently monitored, the back flushing of the filter screen is conveniently and timely carried out, and the orderly filtration is ensured.
The primary filter can be back-flushed on line, the service life of the filter is long, the filtering precision is high, but the pressure resistance of the filter screen is insufficient, and the filter screen is suitable for being used as a primary filter for regenerating high impurity-containing media such as polyester melt; the secondary filter cannot be back-flushed on line, has the service life lower than that of the primary filter, has high filtering precision and high pressure resistance, is suitable for filtering gel and other impurities, is often used as a final filter, and has higher filter element replacement cost; the invention combines the primary filter and the secondary filter, combines the advantages of the primary filter and the secondary filter, effectively avoids the problems of overhigh pressure, serious degradation and increased color value caused by singly using one filter, does not have the situation that color matching is difficult to control in the subsequent dyeing process, prevents the single filter from being in an excessive use state to cause difficult later cleaning, shortens the service life, increases the normal transmission melt channel, prolongs the service life of the filter, has long filtering period, avoids frequent filter replacement, has better adaptability to high-temperature melt filtering and has high filtering precision.
Further, when the primary filter works, the transverse backflushing channels and the melt flow channels are mutually staggered, the transverse backflushing channels are closed, the melt enters the melt flow channels through the melt inlet, passes through the filter screen downwards and flows out of the filter upwards; during backflushing, the central control system controls the filter backflushing shaft to move, the transverse backflushing channels are communicated with the melt flow channels one by one, the melt backflushes the filter screen, and the melt enters the filter backflushing shaft through the transverse backflushing channels and is discharged.
Furthermore, the melt inlet and the melt outlet are provided with pressure sensors, when the pressure difference reaches a set value, the central control system controls the discharge valve at the bottom of the filter backflushing shaft to be opened and controls the filter backflushing shaft to move according to the pressure difference signal, the central control system controls the transverse backflushing channel to be communicated with the melt flow channel by setting the moving position of the filter backflushing shaft, and the central control system controls the moving distance of the filter backflushing shaft by setting the residence time.
Further, a jacket is arranged outside the cylindrical barrel, and the temperature of the jacket is 260-330 ℃. The temperature of the melt in the filter is ensured by the arrangement of the jacket, and the melt is prevented from excessively dropping in the filtering process, so that the influence on the subsequent process is avoided.
Further, a discharge pipe is arranged at the melt inlet of the primary filter. At the initial stage of the melt flowing into the first-stage filter, the flow speed and the flow rate of the melt are not very stable, at the moment, the discharge pipe is opened, the melt at the front section is discharged, after the supply of the melt reaches a stable state, the discharge pipe is closed, the melt is guided into the first-stage filter for filtering, and the filtering stability is ensured.
Further, an exhaust port is arranged at the melt outlet of the primary filter. When the melt flows into the first-stage filter, the exhaust port is opened, air in the first-stage filter is extruded and discharged, after the melt is completely or nearly completely filled in the filter, the exhaust port is closed for normal filtration, and the phenomenon that the relative pressure is excessive due to the fact that excessive air is accumulated in the first-stage filter is avoided, and the influence is caused on the circulation of the melt in the first-stage filter.
Further, a stroke sensor matched with the central control system and used for controlling the moving distance of the filter recoil shaft is arranged at the end part of the filter recoil shaft.
Further, the filtering precision of the primary filter is 20-60 microns; the filtering precision of the secondary filter is 20-40 micrometers. The gradient arrangement of different filter accuracies prolongs the service cycle of the filter and avoids frequent replacement of the filter.
Further, the ratio of the number of the transverse recoil channels to the number of the melt channels is less than or equal to 10%. Assuming that the melt flow channels are 100 groups, when only 1 transverse backflushing channel is arranged on the backflushing shaft of the filter, the backflushing shaft of the filter needs to move 100 times to complete the whole backflushing process, and the normal melt flux of the filter is 99%; if the number of the transverse backflushing channels is 4, the backflushing process is completed only by 25 times, the normal flux of the melt during backflushing is 96%, that is, the more the number of the transverse backflushing channels is, the faster the backflushing is, but the less the normal flux of the melt is, the frequent fluctuation of the melt at the outlet of the filter during the backflushing is, and the fluctuation of the melt pressure is set within 10%, so that the result of considering the flux of the melt and the backflushing efficiency is achieved, and the fluctuation of the pressure during the backflushing can be reduced.
Further, the two-stage filters are at least two and are arranged on different branches and are respectively connected with the first-stage filters through multi-way valves. The arrangement of the two secondary filters ensures normal filtration, when one secondary filter filters, the other secondary filter is in a standby state, and when one secondary filter performs back flushing, the other secondary filter can be started to operate, so that continuous and stable filtration is ensured.
The invention also discloses an operation process of the filtering system, which comprises the following steps:
1) Setting the pressure difference of the two side pressure sensors of the primary filter to be 30-80bar, setting the pressure difference of the two side pressure sensors of the secondary filter to be 10-40bar, and setting the backflushing frequency value of the second filter on any branch;
2) Closing a discharge valve of the primary filter, opening a discharge pipe for discharging for one minute, opening an exhaust port, allowing the melt to enter a large channel from an inlet valve at a flow rate of 0.2-2t/h, allowing the melt to enter a melt flow channel through a liquid inlet on the side wall of the large channel for step-by-step filtration, and closing the exhaust port for continuous filtration when the melt is full of the whole cylinder;
3) Adjusting a booster pump to ensure that the inlet pressure of the melt of the primary filter is more than 65bar, and adjusting the temperature of a jacket to 260-330 ℃;
4) When the pressure difference value of the pressure sensors at the two sides of the primary filter is ultrahigh in a set value, the primary filter starts back flushing, the central control system controls the discharge valve to be opened, the filter back flushing shaft automatically moves downwards, the transverse back flushing channels are communicated with the melt flow channels one by one, the melt back flushing filter screen (4) enters the filter back flushing shaft (2) through the transverse back flushing channels (21) and is discharged, and meanwhile, the control unit adjusts the booster pump to increase the flux so as to maintain the liquid outlet pressure of the primary filter to be more than 40bar;
5) After the moving distance is determined under the cooperation of the stroke sensor, the filter backflushing shaft moves upwards for a plurality of times until the backflushing of all filter screens is finished, and the discharge valve is closed;
6) When the back flushing frequency of the secondary filter is monitored to be higher than a set value, the control system adjusts the multi-way valve to guide the melt of the branch to the other branch, and the melt is filtered through the standby secondary filter.
The beneficial effects of the invention are as follows: the automatic flushing of the filter screen of the primary filter is realized, when the pressure difference between the melt outlet and the melt inlet of the primary filter is overlarge, the back flushing process is automatically started, and the position and the moving distance of a back flushing shaft of the filter of the primary filter are accurately controlled; the circuit structural design is reasonable, and the filtering pertinence to high temperature fuse-element is high, and the flux of normal fuse-element is big when the recoil, and filtration cycle is long, avoids frequent change filter, and the filtration is stable, and filtration efficiency is high, and the filter effect is good.
Drawings
Fig. 1 is a schematic flow structure of the present invention.
FIG. 2 is a schematic diagram showing a normal filtering state of the primary filter according to the present invention.
FIG. 3 is a schematic view of the structure of the filter backflushing shaft of the primary filter of the present invention.
FIG. 4 is a schematic view of a part of the structure of the inner screen and support frame of the primary filter of the present invention.
FIG. 5 is a schematic representation of the backwash state of the primary filter of the present invention.
Fig. 6 is a schematic perspective view of a two-stage filter according to the present invention.
Detailed Description
In order to make the present invention better understood by those skilled in the art, the following description of the technical solutions of the present invention will be made in detail, but not all embodiments of the present invention are apparent to some embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
As shown in figure 1, the filtering system is suitable for high-temperature high-impurity regeneration melt and comprises a booster pump, a pressure sensor 1, a primary filter, a pressure sensor 2, at least two paths of filtering branches which are connected through a multi-way valve and are all provided with secondary filters, a pressure sensor 3 connected to the rear end of the secondary filter and a control unit respectively connected with the structures, wherein the control unit can control the back flushing actions of the primary filter and the secondary filter to be asynchronous.
When the pressure difference between the pressure sensor 1 and the pressure sensor 2 at the two sides of the primary filter reaches a set value, the primary filter automatically starts back flushing, and at the moment, when the control unit senses that the primary filter performs back flushing, the flux of the booster pump is automatically increased to offset the flow reduction caused by back flushing because of the reduction of normal melt flow during back flushing, so that sufficient pressure is ensured to perform back flushing, and the pressure stability of the subsequent working procedure is maintained.
When the pressure difference between the pressure sensor 2 and the pressure sensor 3 at the two sides of the secondary filter reaches a set value, the secondary filter automatically starts back flushing.
When the control unit senses that the backflushing frequency of the secondary filter is higher than a set value, the secondary filter is considered to be invalid, and the multi-way valve is automatically controlled to guide the melt to the secondary filter on the other standby branch. If the filter is backflushed 10 times a day in a normal state, namely, backflushed 2.4 hours, the backflushing frequency is changed to be 2 hours or 1.5 hours once, namely, the failure of the secondary filter is judged, and specific numerical values can be set according to specific conditions.
As shown in fig. 2-5, the primary filter is an automatic melt backflushing filter with the filtering precision of 20-60 micrometers, and at least comprises a cylindrical hollow cylinder 5 and a central control system, wherein a filter backflushing shaft 6, a filter disc 71, a filter screen 72 and a supporting framework 73 are arranged in the cylinder 5, the center of the filter backflushing shaft 6 is a hollow discharging channel 62, and a discharging valve is arranged at the bottom of the discharging channel 62. Specifically, a hollow cylindrical large channel 53 is arranged at the central axis of the cylinder 5, a plurality of groups of liquid inlets are formed in the side wall of the large channel 53 along the height direction of the large channel, and each group of liquid inlets comprises a plurality of liquid inlets symmetrically arranged on the same horizontal plane; a filter backflushing shaft 6 is arranged in the large channel 53 in a vertically movable manner, a plurality of groups of backflushing channels are arranged on the filter backflushing shaft 6 along the height direction of the filter backflushing shaft, each group of backflushing channels comprises a plurality of transversely arranged and symmetrical transverse backflushing channels 61, and the transverse backflushing channels 61 are communicated with a discharge channel 62 in the filter backflushing shaft 6; the top of the filter recoil shaft 6 is provided with a filter disc 71, and the filter disc 71 is an annular sintered felt or mat-type net, and the outer diameter of the filter disc is matched with the inner diameter of the large channel 53 and is in sealing fit with the large channel 53.
The supporting framework 73 comprises an upper supporting net 731 and a lower supporting net 732 which are arranged in parallel up and down with the large channel 53 as a center, a fixing piece 733 used for connecting the ends of the upper supporting net 731 and the lower supporting net 732, the plurality of upper supporting nets 731 and the lower supporting net 732 are arranged to form a supporting framework 73 with the cross section of S, the filter screen 72 is arranged between the upper supporting net 731 and the lower supporting net 732, thus the filter disc 71, the filter screen 72 and the supporting framework 73 form a plurality of S-shaped melt flow channels 74, and the melt flow channels 74 are arranged in opposite communication with the liquid inlet holes. A gap 54 for the filtered liquid to flow is reserved between the outer side of the supporting framework 73 and the inner wall of the cylinder body 5.
The bottom of the cylinder 5 is provided with a melt inlet 51 with an inlet valve, the melt inlet 51 is provided with a pressure sensor 3 which senses that the feeding pressure of the melt is more than 65bar, and a discharge pipe 511 is also arranged at the melt inlet 51; the upper part of the cylinder 1 is provided with a melt outlet 52 with an outlet valve, the melt outlet 52 is also provided with a pressure sensor 4 which senses that the feeding pressure of the melt is more than 40bar, and the melt outlet 52 is also provided with an exhaust port 521.
When filtering, the transverse backflushing channels 61 and the liquid inlet holes are staggered, namely, the transverse backflushing channels 61 are propped against the inner wall of the large channel 53, so that the transverse backflushing channels 61 are in a closed state, at the moment, the melt enters the melt flow channel 74 through the melt inlet 51, flows upwards through the gap 54 between the supporting framework 73 and the inner wall of the cylinder 5 after being filtered by the filter screen 72 downwards along the arrow direction, and finally flows out of the filter from the melt outlet 52.
In order to ensure the stability of filtration, before the melt enters the filter through the melt inlet 51, the inlet valve of the melt inlet 51 is closed, a part of the melt with unstable feeding is discharged through the discharge pipe 511, and after the feeding is stable, the inlet valve is opened to allow the melt to normally enter the filter, specifically, in the embodiment, the feeding flow rate of the melt is ensured to be 0.2-2t/h; at this time, the outlet valve of the melt outlet 52 is kept in a closed state, the vent is opened, and as the melt enters, the gas in the filter is gradually exhausted through the vent until the barrel 5 is full of the melt, the vent 521 is closed, and the outlet valve is opened for normal filtration. The above actions form a protection program, which has good protection effect on the filter.
The bottom end of the filter recoil shaft 6 is provided with a travel sensor which is connected with a central control system and used for controlling the moving distance of the filter recoil shaft 6; the bottom of the cylinder 5 is provided with a locator connected with a central control system.
When the pressure difference between the two pressure sensors at the melt inlet 51 and the melt outlet 52 reaches 40bar after filtration is carried out for a period of time, a signal is sent to a central control system, the central control system receives the pressure difference signal and then controls a discharge valve to be opened, meanwhile, the filter backflushing shaft 6 moves downwards, when a transverse backflushing channel moving to the bottommost end of the filter backflushing shaft 6 is communicated with a melt flow channel at the bottommost part of the barrel 5, a positioner sends a signal to a control unit to control the filter backflushing shaft 6 to stop moving downwards, the default position is 0 point, a backflushing action is started, at the moment, the filtered melt flows downwards from the top of the barrel, the accumulated attachments on the filter screen 72 are washed downwards through a filter screen 72, the washed liquid passes through a liquid inlet of a large channel 53 from the melt flow channel 74 and is discharged from the bottom of a discharge channel 62 of the filter backflushing shaft 6 through a transverse backflushing channel 61. After the filter backflushing shaft 6 stays at the 0-point position for 10-60s, the central control system controls the filter backflushing shaft 6 to start moving upwards, the moving distance is controlled by the stroke sensor, backflushing is performed sequentially from bottom to top until backflushing of all filter screens is completed, and the discharge valve is closed. Specifically, when the support framework has 100 groups, the filter backflushing shaft is provided with 4 groups of transverse backflushing channels, and the filter backflushing shaft needs to be moved 25 times at the moment, so that a complete backflushing process is completed. In the embodiment, the ratio of the number of the transverse backflushing channels to the number of the melt channels is less than or equal to 10%, so that pressure fluctuation during backflushing is reduced, even if the normal melt channels reach more than 90%, the pressure fluctuation is less than 10%, and the 10% pressure fluctuation is regulated by the first booster pump and the second booster pump, so that continuous and stable filtration is ensured.
TABLE 1 influence of the ratio of the number of Filter screens to the number of Filter backflushing shafts on the filtration
A jacket (not shown in the figure) is arranged outside the cylinder 5, and is arranged to cover the outer wall of the whole cylinder 5, and the temperature of the jacket is 260-330 ℃, so that the melt in the cylinder 5 can be ensured to have higher temperature in the filtering process.
As shown in fig. 6, the secondary filter is a filter element type melt filter, and comprises a fixed plate 11, a lower cover plate 12, a filter element column 13, an upper cover plate 14 and an outer cylinder, wherein a melt inlet 121 is arranged on the side wall of the lower cover plate 12, a plurality of shunt ports 122 are arranged at the top, and each shunt port 122 is communicated with the melt inlet 121 in the lower cover plate 12; the filter element column 13 is composed of a filter rod 133, a filter medium 132 and a framework outer net 131, wherein a plurality of small holes are formed in the outer wall of the filter rod 133 for allowing melt to enter, the holes are 100 meshes, a melt channel 134 is arranged in the center, the small holes are communicated with the melt channel 134, the lower end of the melt channel 134 is closed and is not communicated with other parts except the small holes, the upper end of the melt channel 134 penetrates through the top of the filter rod 133, the filter medium 132 is wrapped on the filter rod 133, the filter medium 132 is a mat-type net made of stainless steel fiber sintered felt, the filter precision is 20 mu m, the framework outer net 131 is erected on the filter medium 132, the framework outer net 131 is a stainless steel framework net, and the filter precision is 100 meshes; the filter element column 13 is arranged between the upper cover plate 14 and the lower cover plate 12, and the outer cylinder is sleeved outside the filter element column 13; the upper cover plate 14 is provided with a melt outlet 141, and the melt outlet 141 is communicated with the melt channel 134; the melt enters through the melt inlet 121, passes through the shunt opening 122, then enters the melt channel 134 through the framework outer net 131, the filter medium 132 and the small holes, and flows out through the melt outlet 141, thus completing the whole filtration. The method comprises the steps of applying a secondary filter to melt filtration, fixing the lower end of a filter element column 13 on a lower cover plate 12, sleeving an upper outer cylinder, arranging an inlet and an outlet on the outer cylinder, respectively corresponding to a melt inlet 121 on the lower cover plate 12 and a melt outlet 141 on an upper cover plate 14, forming a melt inlet and outlet channel, pressing the upper cover plate 14 on the upper end of a filter rod 133 through threaded connection, at the moment, communicating a melt channel 134 with the upper part of the upper cover plate 14, communicating the upper cover plate 14 with the melt outlet 141, finally fixing the lower cover plate 12 with a mounting plate, putting the secondary filter into an outer shell through the mounting plate and the upper cover plate 14, enabling a melt to enter a shunt opening 122 through a melt inlet 121 of the lower cover plate 12, enter between the outer cylinder and the filter element column 13, enter a filter medium 132 through a framework outer net 131, enter the melt channel 134 through small holes after the filtering process is completed, rise to the top of the filter rod 133, flow out through the melt outlet 141 at the upper cover plate 14, and can finish multiple times of filtration on the same cross section, and then discharge, wherein the filter medium 132 adopts stainless steel fiber sintered felt, so as to remove the melt and the filter medium, and the filter medium is not easy to block, and the filter medium is not easy to be deformed, and the filter medium is not easy to be corroded by adopting a framework, and the filter medium is resistant to filter medium, and the filter medium is resistant to coarse to corrosion, and has been deformed; the filter core column 13 is installed in the center and the peripheral position of the lower cover plate 12, when the melt enters from the melt inlet 121, the melt passes through the split-flow ports 122 under the pressure action and the inertia action of the melt, and the melt passes through the filter cores 13 positioned in the center and the periphery respectively, so that the filtering accuracy is high, the service life is long, the working stability is good, the equipment utilization rate can be improved, and the yield can be improved.
The operation process of the filtering system comprises the following steps:
1) Setting the pressure difference value between the two side pressure sensors 1 and 2 of the primary filter to be 30-80bar, setting the pressure difference between the two side pressure sensors 2 and 3 of the secondary filter to be 10-40bar, and setting the backflushing frequency value of the second filter on any branch to be 2-20 times per day;
2) Closing a discharge valve of the primary filter, opening a discharge pipe for discharging for 10-80 minutes, opening an exhaust port, and continuously filtering when the melt enters the large channel from the inlet valve at a flow rate of 0.2-2t/h and enters the melt flow channel through a liquid inlet on the side wall of the large channel for step-by-step filtration, and closing the exhaust port when the melt is full of the whole cylinder;
3) Adjusting a booster pump to ensure that the inlet pressure of the melt of the primary filter is more than 65bar, and adjusting the temperature of a jacket to 260-330 ℃;
4) When the pressure difference value of the pressure sensors at the two sides of the primary filter is ultrahigh in a set value, the primary filter starts back flushing, the central control system controls the discharge valve to be opened, the filter back flushing shaft automatically moves downwards, a transverse back flushing channel at the lowest end of the filter back flushing shaft is communicated with a melt flow channel at the lowest part of the cylinder body, the melt backflushes the filter screen, the melt enters the filter back flushing shaft through the transverse back flushing channel and is discharged, back flushing of part of the filter screen is completed, and the filter back flushing shaft moves upwards until back flushing of all the filter screens is completed; meanwhile, the control unit adjusts the booster pump to increase flux so as to maintain the liquid outlet pressure of the primary filter to be more than 40bar;
5) After the moving distance is determined under the cooperation of the stroke sensor, the filter backflushing shaft moves upwards for a plurality of times until the backflushing of all filter screens is finished, and the discharge valve is closed;
6) The primary filter finishes back flushing to perform normal filtration, when the pressure difference value of the pressure sensor 2 and the pressure sensor 3 at the two sides of the secondary filter is ultrahigh in set value, the secondary filter starts back flushing,
7) When the back flushing frequency of the second filter is monitored to be higher than a set value, the control system adjusts the multi-way valve to guide the melt of the branch to the other branch, and the melt is filtered through the standby second filter;
8) Repeating the above process to complete the filtering process.
Description of experimental data
Before the melt enters the filter: the pipe diameter is 25-100mm, the pipe temperature is 290-298 ℃, the intrinsic viscosity is 0.68dl/g, the kinematic viscosity is 250-300Pa [ S ], the flow rate is 1.5-3m/min, the b value is 3, and the impurity content (calculated by ash content, 0.45%) is realized.
The melt filtrate is obtained by respectively utilizing the independent filtration of the first filter, the independent filtration of the second filter and the combined filtration of the invention.
*1 impurity content of the final product: the ash content is used for representing the impurity content of the final product, and the good and bad filtering effect is reflected.
*2b value: the yellow-blue index of the polyester product reflects the degradation of the polyester due to the temperature rise.
The foregoing detailed description is provided to illustrate the present invention and not to limit the invention, and any modifications and changes made to the present invention within the spirit of the present invention and the scope of the appended claims fall within the scope of the present invention.
Claims (8)
1. The filtering system is used for regenerating melt with high temperature and impurities and at least comprises a booster pump, a primary filter, a secondary filter and a control unit which are connected in sequence;
the primary filter is an automatic melt backflushing filter and at least comprises a cylindrical barrel (5) and a central control system, wherein a filter backflushing shaft (6), a filter disc (71), a filter screen (72) and a supporting framework (73) are arranged in the center of the barrel (5); the bottom of the cylinder body (5) is provided with a melt inlet (51), the upper part of the cylinder body is provided with a melt outlet (52), and pressure sensors are arranged at the melt inlet (51) and the melt outlet (52); a plurality of symmetrical transverse backflushing channels (61) are arranged on the backflushing shaft (6) of the filter; the supporting framework (73) forms a plurality of S-shaped melt flow passages (74); the transverse recoil channels (61) and the melt flow channels (74) are in a mutually staggered and one-by-one communicated state;
the secondary filter is a filter element type melt filter, the filtering precision of the secondary filter is greater than that of the primary filter, the secondary filter comprises a hollow cover plate which is vertically symmetrical and a filter element column (13) which is arranged in the middle, a round melt inlet (121) is arranged on the side surface of the lower cover plate (12), a round melt outlet (141) is arranged on the side surface of the upper cover plate (14), and the filter element column (13) consists of a hollow shell, a filter rod (133) which is arranged in the shell and a filter medium (132) which surrounds the filter rod (133);
the control unit is respectively connected with two pressure sensors positioned at two sides of the primary filter, a pressure sensor positioned at the liquid outlet of the secondary filter, a booster pump, the primary filter and the secondary filter, and when the pressure difference between the liquid inlet and the liquid outlet of the primary filter reaches a set value, the control unit controls the primary filter to perform back flushing, and the booster pump is regulated to increase flux; when the pressure difference of two pressure sensors at the liquid inlet and the liquid outlet of the secondary filter reaches a set value, the control unit adjusts the secondary filter to perform back flushing; the control unit is also used for controlling the primary filter and the secondary filter to start a back flushing program at the same time;
when the primary filter works, the transverse backflushing channels (61) and the melt flow channels (74) are staggered, the transverse backflushing channels (61) are closed, the melt enters the melt flow channels (74) through the melt inlet (51), passes through the filter screen (72) downwards, and flows out of the filter upwards; during backflushing, the central control system controls the filter backflushing shaft (6) to move, the transverse backflushing channels (61) are communicated with the melt flow channels (74) one by one, and the melt backflushing filter screen (72) enters the filter backflushing shaft (6) through the transverse backflushing channels (61) and is discharged;
the melt inlet (51) and the melt outlet (52) are provided with pressure sensors, when the pressure difference reaches a set value, the central control system controls the discharge valve at the bottom of the filter backflushing shaft (6) to open and controls the filter backflushing shaft (6) to move according to the pressure difference signal, the central control system controls the transverse backflushing channel (61) to be communicated with the melt flow channel (74) by setting the moving position of the filter backflushing shaft (6), and the central control system controls the moving distance of the filter backflushing shaft (6) by setting the residence time.
2. The filtration system of claim 1, wherein: the outside of the cylindrical barrel body (5) is provided with a jacket, and the temperature of the jacket is 260-330 ℃.
3. The filtration system of claim 1, wherein: a discharge pipe (511) is arranged at the melt inlet (51) of the primary filter; an exhaust port (521) is arranged at the melt outlet (52) of the primary filter.
4. The filtration system of claim 1, wherein: the end part of the filter backflushing shaft (6) is provided with a travel sensor which is matched with the central control system and used for controlling the moving distance of the filter backflushing shaft (6).
5. The filtration system of claim 1, wherein: the filtering precision of the primary filter is 20-60 micrometers; the filtering precision of the secondary filter is 20-40 micrometers.
6. The filtration system of claim 1, wherein: the ratio of the number of the transverse recoil channels (61) to the number of the melt channels (74) is less than or equal to 10 percent.
7. The filtration system of claim 1, wherein: the two-stage filters are at least two and are arranged on different branches and are respectively connected with the first-stage filters through multi-way valves.
8. A process for operating the filtration system of claim 1, comprising the steps of:
1) Setting the pressure difference of the two side pressure sensors of the primary filter to be 30-100bar, setting the pressure difference of the two side pressure sensors of the secondary filter to be 10-40bar, and setting the backflushing frequency value of the second filter on any branch;
2) Closing a discharge valve of the primary filter, opening a discharge pipe for discharging for 10-80 minutes, opening an exhaust port, and continuously filtering when the melt enters the large channel from the inlet valve at a flow rate of 0.2-2t/h and enters the melt flow channel through a liquid inlet on the side wall of the large channel for step-by-step filtration, and closing the exhaust port when the melt is full of the whole cylinder;
3) Adjusting a booster pump to ensure that the inlet pressure of the melt of the primary filter is more than 65bar, and adjusting the temperature of a jacket to 260-330 ℃;
4) When the pressure difference value of the pressure sensors at the two sides of the primary filter is ultrahigh in a set value, the primary filter starts back flushing, the central control system controls the discharge valve to be opened, the filter back flushing shaft automatically moves downwards, the transverse back flushing channels are communicated with the melt flow channels one by one, the melt back flushing filter screen (4) enters the filter back flushing shaft (2) through the transverse back flushing channels (21) and is discharged, and meanwhile, the control unit adjusts the booster pump to increase the flux so as to maintain the liquid outlet pressure of the primary filter to be more than 40bar;
5) After the moving distance is determined under the cooperation of the stroke sensor, the filter backflushing shaft moves upwards for a plurality of times until the backflushing of all filter screens is finished, and the discharge valve is closed;
6) When the back flushing frequency of the secondary filter is monitored to be higher than a set value, the control system adjusts the multi-way valve to guide the melt of the branch to the other branch, and the melt is filtered through the standby secondary filter.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992016351A1 (en) * | 1991-03-25 | 1992-10-01 | Erema Engineering Recycling Maschinen Und Anlagen Gesellschaft M.B.H. | Filtering device for fluids to be purified |
| EP0707878A1 (en) * | 1994-10-19 | 1996-04-24 | Bematec Sa | Filter apparatus with back flow cleaning |
| CN101700443A (en) * | 2009-11-03 | 2010-05-05 | 苏州汇龙膜技术发展有限公司 | High-viscosity fluid filtering device with backwashing function |
| CN203123690U (en) * | 2013-03-13 | 2013-08-14 | 古春林 | Fine and efficient pressurizing backlash and recharge filter unit |
| CN105396353A (en) * | 2015-12-18 | 2016-03-16 | 浙江宇丰机械有限公司 | High-viscosity material full-automatic backwashing coarse-filtration system |
-
2018
- 2018-04-16 CN CN201810338944.8A patent/CN108295531B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992016351A1 (en) * | 1991-03-25 | 1992-10-01 | Erema Engineering Recycling Maschinen Und Anlagen Gesellschaft M.B.H. | Filtering device for fluids to be purified |
| EP0707878A1 (en) * | 1994-10-19 | 1996-04-24 | Bematec Sa | Filter apparatus with back flow cleaning |
| CN101700443A (en) * | 2009-11-03 | 2010-05-05 | 苏州汇龙膜技术发展有限公司 | High-viscosity fluid filtering device with backwashing function |
| CN203123690U (en) * | 2013-03-13 | 2013-08-14 | 古春林 | Fine and efficient pressurizing backlash and recharge filter unit |
| CN105396353A (en) * | 2015-12-18 | 2016-03-16 | 浙江宇丰机械有限公司 | High-viscosity material full-automatic backwashing coarse-filtration system |
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