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CN-121819456-B - Six-micrometer high-precision filtering separation method

CN121819456BCN 121819456 BCN121819456 BCN 121819456BCN-121819456-B

Abstract

The invention relates to the technical field of precise fluid separation, and discloses a six-channel micron high-precision filtering separation method which comprises the steps of controlling fluid to be cooled to supersaturated precipitation temperature to generate colloid flocculate, sequentially conveying the fluid through a six-level physical separation sequence consisting of gravity sedimentation, centrifugal rotational flow, magnetic adsorption and multi-level filter media, collecting terminal filtering pressure difference in real time and calculating resistance growth rate, and when the resistance growth rate exceeds a critical compaction threshold value, feeding back and adjusting front end cooling rate or conveying temperature to optimize structural rigidity of the flocculate.

Inventors

  • BU CHENGYI
  • SONG YANGBO

Assignees

  • 湖南四季油脂有限公司

Dates

Publication Date
20260508
Application Date
20260313

Claims (10)

  1. 1. The six-path micron high-precision filtering and separating method is characterized by comprising the following steps of: S1, a temperature control precipitation step, namely pumping a solid-liquid mixed fluid into a temperature control adjusting tank, and controlling the temperature of the fluid to be reduced to a supersaturated precipitation temperature at a preset cooling rate so as to convert dissolved impurities in the fluid into suspended colloidal flocs; S2, a multistage physical separation step, namely sequentially conveying the solid-liquid mixed fluid treated in the step S1 through a six-stage physical separation sequence consisting of a gravity sedimentation zone, a centrifugal cyclone, a metal interception net, a magnetic adsorption bed, a deep fiber filter core and a terminal microporous membrane so as to intercept impurities with different particle diameters step by step; S3, a resistance characteristic extraction step, namely collecting real-time pressure difference data delta P (t) of two sides of an inlet and an outlet of the terminal microporous membrane at a preset sampling frequency when fluid passes through the terminal microporous membrane, and calculating a resistance increase rate k representing the compaction degree of a filter cake layer based on the real-time pressure difference data; s4, a source feedback regulation step, namely, regulating and controlling the resistance increase rate k and a preset critical compaction threshold value Comparing when the resistance increase rate k is greater than the critical compaction threshold When the filter cake layer is judged to be in an over-compaction state, a feedback regulation action is performed, namely, the cooling rate in the step S1 is reduced, or the conveying temperature of the fluid conveyed to the terminal microporous membrane in the step S2 is increased, so that the average particle size of colloidal flocs is increased or the compressibility of the colloidal flocs is reduced, until the resistance increase rate k of the subsequent collection returns to be less than or equal to a critical compaction threshold value Within a range of (2).
  2. 2. The six-channel micron high-precision filtering separation method according to claim 1, wherein the specific implementation actions of each stage of physical separation sequence in the step S2 are as follows, gravity sedimentation separation, controlling fluid to flow through a sedimentation tank in a laminar flow state, enabling particles with Stokes diameter larger than 100 μm to be settled to a tank bottom by means of density difference, centrifugal cyclone separation, guiding fluid to enter a cyclone tangentially, enabling particles with density larger than a fluid matrix to be separated to the wall surface of the cyclone by means of a centrifugal force field, intercepting a metal net, enabling the fluid to pass through a rigid metal net with a pore diameter of 50-80 μm, intercepting the hard particles, magnetic adsorption separation, guiding the fluid to flow through a runner provided with a permanent magnet array, absorbing ferromagnetic particles in the fluid by means of a magnetic field, deep fiber filtration, guiding the fluid to pass through a non-woven fiber medium with a pore diameter which is reduced in a gradient manner along the flowing direction, intercepting soft colloid of 10-50 μm, and terminal microporous membrane separation, guiding the fluid to pass through a microporous membrane with a certain interception pore diameter, removing submicron-level particles, and taking the submicron-level particles as an acquisition point of pressure difference data deltaP (t) in the step S3.
  3. 3. The method of claim 1, wherein in step S1, the cooling rate is controlled to be between 0.5 ℃ and 2.0 ℃ and the fluid is mechanically stirred during the cooling process, and the shearing rate of the stirring is controlled to be 10 To 50 Between them.
  4. 4. The six-channel micron high-precision filtering separation method according to claim 1 is characterized in that in the step S3, the calculation process of the resistance increase rate k comprises the steps of obtaining a pressure difference-time sequence in a current filtering period, eliminating pressure pulsation noise with the frequency higher than 50Hz in the sequence, performing first-order differential operation on the denoised sequence to obtain a change slope of the pressure difference along with time, and taking the change slope as the resistance increase rate k.
  5. 5. The six micron high-precision filtration separation method according to claim 2, wherein the depth fiber filtration further comprises a medium regeneration step based on flow rate attenuation by monitoring the flow rate of the fluid through the nonwoven fiber medium in real time and when the flow rate is attenuated to the initial flow rate And impacting the non-woven fiber medium in a reverse pulse mode by using a cleaning medium which is homogeneous with the filtered fluid to enable the trapped colloid to fall off.
  6. 6. The six-pass micron high-precision filtering separation method according to claim 1, wherein the step S4 further comprises a flow limiting logic based on shear stress, wherein the actual shear stress of the fluid on the surface of the terminal microporous membrane is calculated based on the current fluid delivery flow and the flow channel geometric parameters of the terminal microporous membrane Actual shear stress With a preset colloidal yield stress Comparing when When the current conveying flow is maintained, if The delivery flow rate is reduced.
  7. 7. The six-pass micron high-precision filtering separation method according to claim 1, wherein the terminal microporous membrane separation further comprises a vibration cleaning step of applying mechanical vibration with the frequency of 20kHz to 40kHz to the terminal microporous membrane by using an ultrasonic generator during the filtering process, wherein the mechanical vibration is used for destroying the adhesive force of colloid particles on the surface of the terminal microporous membrane.
  8. 8. The six-pass micron high-precision filtering separation method according to claim 1, wherein the method further utilizes a blocking characteristic factor To evaluate the occlusion status of the separation sequence, wherein the occlusion feature factor Calculated according to the following formula: wherein DeltaP (t) is real-time differential pressure data measured at the current time t, For the initial pressure difference of the terminal microporous membrane in the clean state, mu is the dynamic viscosity of the fluid, v is the apparent flow rate of the fluid through the terminal microporous membrane, t is the accumulated running time after the current filtration cycle begins, and the source feedback regulation step further comprises the steps of when the obtained blocking characteristic factor is calculated When the time t presents an exponential growth trend, the nonlinear depth blockage is judged to occur, and the feedback regulation action is triggered.
  9. 9. The method according to claim 2, further comprising a step of removing water by coalescence between gravity sedimentation separation and centrifugal cyclone separation, wherein the fluid is guided to flow through a coalescing assembly comprising hydrophilic fibers, micro-dispersed water droplets in the fluid are adsorbed and coalesced on the surface of the hydrophilic fibers to form large droplets having a diameter of more than 500 μm, and the large droplets are separated from the fluid by a difference in oil-water density.
  10. 10. A six micron high accuracy filter separation method according to claim 1 wherein the feedback conditioning action follows a hierarchical execution strategy when the rate of resistance increase k exceeds a critical compaction threshold Reducing the drive frequency of the fluid transfer pump in the physical separation sequence when the magnitude of the resistance increase rate k exceeds a critical compaction threshold When the amplitude of (2) is between 10% and 30%, the cooling rate in step S1 is reduced while the driving frequency is reduced, when the resistance increase rate k exceeds the critical compaction threshold When the amplitude of the temperature is greater than 30%, suspending the filtration and conveying, starting a heating program to raise the temperature of the fluid in the temperature control and regulation area to re-dissolve colloid particles, and restarting the step S1 at a cooling rate lower than the original set value.

Description

Six-micrometer high-precision filtering separation method Technical Field The invention relates to the technical field of precise fluid separation, in particular to a six-channel micron high-precision filtering separation method. Background Currently, in the industrial fluid purification process, aiming at a heterogeneous system containing trace suspended solids or colloidal impurities, a physical field synergistic fractionation process is generally adopted in the industry, and liquid-solid separation is realized under the condition of not introducing chemical reagents by utilizing the selective action of different physical fields on the particle size or density of the impurities through the process combination of mechanical rough filtration, centrifugal sedimentation, gravity delamination and terminal pressure filtration. However, when the object to be treated is a soft floc system rich in thermosensitive colloid, wax or having thixotropic property, the fluid transportation mode based on constant flow rate or constant pressure gradient in the prior art shows intrinsic limitation, such soft impurities have non-newton fluid characteristics and lower yield stress threshold, the continuous shear stress field applied by conventional transportation equipment often neglects the rheological property, for example, patent publication No. CN213192743U discloses a high-efficiency multistage filtering colloid impurity device, the scheme is provided with multistage filtering grids with different apertures, colloid and fiber impurities are removed by utilizing physical interception and classification, while the stage progressive screening logic is used for treating rigid particles or long fibers to have a certain effect, but facing thixotropic soft colloid, the lack of process perception and dynamic regulation open-loop treatment mode is difficult to be applicable, the device lacks the real-time intervention capability of fluid thermodynamic state, no feedback mechanism based on terminal resistance characteristics, the soft colloid is easy to generate rheological extrusion deformation when being piled up on the surface of the grids and bearing accumulated hydraulic pressure, once the colloid generates the quasi-liquefaction deformation, the size is smaller than that of the aperture penetrating medium, thus leading to downstream working procedure, the filtering colloid is difficult to be self-adaptive to be in the dynamic filter cake or the state of fluctuation, and the bottleneck precision is difficult to be separated. Therefore, how to construct a dynamic transport and separation mechanism capable of actively adapting to the rheological properties of soft impurities, and preventing colloid from deformation penetration or compact blockage while ensuring flux becomes the technical problem to be solved by the invention. Disclosure of Invention The invention provides a six-channel micron high-precision filtering and separating method, which comprises the following steps: S1, a temperature control precipitation step, namely pumping a solid-liquid mixed fluid into a temperature control adjusting tank, and controlling the temperature of the fluid to be reduced to a supersaturated precipitation temperature at a preset cooling rate so as to convert dissolved impurities in the fluid into suspended colloidal flocs; S2, a multistage physical separation step, namely sequentially conveying the solid-liquid mixed fluid treated in the step S1 through a six-stage physical separation sequence consisting of a gravity sedimentation zone, a centrifugal cyclone, a metal interception net, a magnetic adsorption bed, a deep fiber filter core and a terminal microporous membrane so as to intercept impurities with different particle diameters step by step; S3, a resistance characteristic extraction step, namely collecting real-time pressure difference data delta P (t) of two sides of an inlet and an outlet of the terminal microporous membrane at a preset sampling frequency when fluid passes through the terminal microporous membrane, and calculating a resistance increase rate k representing the compaction degree of a filter cake layer based on the real-time pressure difference data; s4, a source feedback regulation step, namely, regulating and controlling the resistance increase rate k and a preset critical compaction threshold value Comparing when the resistance increase rate k is greater than the critical compaction thresholdWhen the filter cake layer is judged to be in an over-compaction state, a feedback regulation action is performed, namely, the cooling rate in the step S1 is reduced, or the conveying temperature of the fluid conveyed to the terminal microporous membrane in the step S2 is increased, so that the average particle size of colloidal flocs is increased or the compressibility of the colloidal flocs is reduced, until the resistance increase rate k of the subsequent collection returns to be less than or equal to a critical compaction