Filter material for solid-liquid separation, filter bag and online regeneration method thereof

Abstract

The present application relates to a kind of filter materials for solid-liquid separation, filter bag and its on-line regeneration method, filter material includes water inlet layer, transition layer and water outlet layer, water inlet layer is melt-blown layer, transition layer is coarse denier fiber needle felt, water jet felt or needle punching water jet composite felt, water outlet layer is PTFE microporous membrane.Filter bag is two ends through type structure, is made of bag body and bag head connected to its two ends, bag head is equipped with elastic expansion ring in, bag body and bag head are made of filter material.On-line regeneration method of filter bag, including: manufacturing filter material;Filter bag is made using filter material;The filter bag prepared is installed in the box of filter device;The upper end opening of filter bag is communicated with the water inlet of filter device, and the water outlet of filter device is communicated with the outer side of filter bag;Mud scraping device in filter bag periodically reciprocates up and down, and the mud cake on the water inlet layer of inner side of filter bag is scraped, to realize the real-time filtration and on-line regeneration of filter bag.The filter material and filter bag have good solid-liquid separation effect, high filtration precision and long service life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sewage treatment, and particularly relates to a filter material for solid-liquid separation, a filter bag and an online regeneration method thereof. BACKGROUND

[0002] In recent years, with the rapid development of urbanization and industrialization in China, the discharge amount of domestic wastewater increases year by year, leading to deterioration of natural water bodies and a grim situation of water resource pollution. Therefore, the state has continuously improved the degree of attention and support for the environmental protection industry, and the sewage treatment industry has developed rapidly.

[0003] In the prior art, the commonly used process methods in the sewage treatment system for solid-liquid separation include filtration and sedimentation. The filtration method refers to the use of filter media (sieve, gauze and granular material) to intercept suspended solids in wastewater. However, the filter media is prone to be blocked, and the flux needs to be restored by manual or mechanical cleaning or replacement of new filter media, which increases the operation cost, and the process operation is complex. In addition, the filter media used often has a large pore size, poor filtration effect and short service life. The sedimentation method is based on the difference in relative density between suspended solids and water, and uses gravity sedimentation to separate the suspended solids. The suspended solids can be naturally settled, coagulated settled or chemically precipitated. However, this method requires a large floor area and has a high failure rate. SUMMARY

[0004] The purpose of the present application is to provide a filter material for solid-liquid separation, a filter bag and an online regeneration method thereof. The filter material and the filter bag have good solid-liquid separation effect, high filtration precision and long service life.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows: a filter material for solid-liquid separation, which comprises a water inlet layer, a transition layer and a water outlet layer stacked together in sequence. The water inlet layer is a melt-blown layer, the transition layer is a coarse-denier fiber needle felt, a water-jet felt or a needle-jet water-jet composite felt, and the water outlet layer is a PTFE microporous membrane.

[0006] Further, the grammage of the filter material is 300-1000 g / m 2 ; the grammage of the melt-blown layer is 50-200 g / m 2 , and the grammage of the transition layer is 250-800 g / m 2 .

[0007] Further, the fiber fineness of the melt-blown layer is 0.5-5 pm, and the fiber fineness of the transition layer is 3.8 dtex; the pore size of the melt-blown layer is 10-20 pm, the pore size of the transition layer is 30-100 pm, and the pore size of the PTFE microporous membrane is 0.1-5 pm, the average pore size is 2 pm, and the thickness is 2-10 pm.

[0008] Further, the material of the melt-blown layer is polyester or polypropylene, and the material of the transition layer is one or a combination of dacron, polyphenylene sulfide, polyphenyl sulfone sulfoxide, aramid, polytetrafluoroethylene, polyimide, arnos, and acrylic.

[0009] The application also provides a filter bag based on the filter material for solid-liquid separation, which has a through structure at both ends, is composed of a bag body and bag heads connected to both ends of the bag body, and is provided with an elastic expanding ring in the bag head.

[0010] Further, the water inlet layer and the water outlet layer of the filter material are respectively located on the inner side and the outer side of the filter bag, and the shape and size of the elastic expanding ring are matched with the hole plate of the filter device.

[0011] The application also provides an online regeneration method of the filter bag, which comprises the following steps:

[0012] According to the basis weight of the transition layer, a needle punching process, a water jet process or a needle punching and water jet combined process is selected, and a melt-blown technology and a hot pressing film coating technology are combined to form the filter material; the filter material is used to form two bag heads and a bag body, and then the three parts are sewn into a through filter bag at both ends;

[0013] A plurality of prepared filter bags are installed in the box of the filter device, the upper and lower bag heads of each filter bag are respectively installed on the upper and lower hole plates of the box to keep the bag body of the filter bag in a vertical state; the upper end opening of the filter bag is communicated with the water inlet of the filter device, and the water outlet of the filter device is communicated with the outer side of the filter bag, so that the sewage flows into the filter bag through the upper end opening of the filter bag, and is self-driven for filtration by the self-power of the sewage, and the clean water is discharged from the water outlet.

[0014] The mud scraping device arranged in the filter bag is periodically reciprocated up and down to periodically scrape off the mud cake on the water inlet layer of the inner side of the filter bag, so as to realize real-time filtration and online regeneration of the filter bag.

[0015] Further, the specific manufacturing method of the filter material is as follows: first, one of a coarse denier fiber needle punching felt, a water jet felt or a needle punching and water jet combined felt is selected, and is subjected to shaping, singeing and first hot calendering to serve as a transition layer; then the transition layer is pulled on a roller, a high-speed hot air flow is used to extrude polymer melt at the spinning hole of a rotating centrifugal die head to form ultrafine fibers on one side of the transition layer on the roller to form a melt-blown layer, and then second hot calendering is performed; finally, a PTFE microporous membrane is subjected to hot pressing film coating treatment with the other side of the transition layer to form a close and delicate combination between the water outlet layer and the transition layer, so as to manufacture the filter material.

[0016] Further, the pressure of the natural gas used for singeing is controlled at 0.1-0.5 MPa, and the mixing ratio of the natural gas to air is 1:1; the temperature of the hot calendering roller is 60-200 DEG C.

[0017] Further, the mud scraping device mainly comprises a motor, a rotating shaft mechanism, a plurality of spiral steel rings, a plurality of pull ropes and a plurality of fixed pulleys; the rotating shaft mechanism comprises a rotating shaft horizontally arranged on the upper side of the filter bag in the box and bearing seats at two ends of the rotating shaft, the bearing seats are mounted on the box, and the rotating shaft is driven by the motor; one spiral steel ring is arranged in each filter bag, and the size of the spiral steel ring is adapted to the inner side of the filter bag; the filter bags installed in the filter device are double, each two filter bags form a group, three pull ropes and a fixed pulley are arranged for each group, the fixed pulley is arranged below the two spiral steel rings in the group, one pull rope is wound around the fixed pulley and connected to the lower ends of the two spiral steel rings, and the other two pull ropes are connected to the upper ends of the two spiral steel rings and wound in the wire slot of the rotating shaft in the opposite direction, so that when the motor is rotated forward or reversely, one pull rope is wound and the corresponding spiral steel ring is lifted upward, the spiral steel ring drags another spiral steel ring to move downward through the pull rope on the fixed pulley, and reciprocating mud scraping is formed.

[0018] Compared with the prior art, the filter material and the filter bag provided by the application have the following beneficial effects: the filter material and the filter bag provided by the application are composed of a plurality of gradient structures, the filtering precision of solid-liquid separation is improved, and the process is simplified in actual production. The water inlet layer adopts a melt-blown layer, and the water outlet layer adopts a PTFE coating technology, the melt-blown layer has a large water outlet amount and a moderate pore size, and is easy to slide off sludge, and the PTFE coating technology further improves the water quality. The filter bag online regeneration method provided by the application adopts a double-bag-head through type design, does not need a power source, and is self-driven for filtration by the power of sewage itself, thereby saving energy, reducing consumption and reducing carbon. In addition, the method can periodically clean the pollutants on the filter bag, not only realizes online regeneration of the filter bag and improves the service life of the filter bag, but also improves the flux stability of solid-liquid separation, further improves the operation efficiency, and realizes high-efficiency water storage. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a filter material structure schematic diagram of an embodiment of the application;

[0020] Figure 2 is a filter bag structure schematic diagram of an embodiment of the application;

[0021] Figure 3 is an implementation structure schematic diagram of the filter bag online regeneration method of an embodiment of the application. DETAILED DESCRIPTION

[0022] The application will be further described below in combination with the drawings and embodiments.

[0023] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0024] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a reference to the presence of a feature, step, operation, device, component, and / or combinations thereof.

[0025] As shown in Figure 1 , the present embodiment provides a filter material for solid-liquid separation, which comprises a water inlet layer 1, a transition layer 2 and a water outlet layer 3 stacked together in sequence, the water inlet layer is a melt-blown layer, the transition layer is a coarse fiber needle felt, a water jet felt or a needle water jet composite felt, and the water outlet layer is a PTFE microporous membrane.

[0026] In the present embodiment, the grammage of the filter material is 300-1000 g / m 2 ; wherein the grammage of the melt-blown layer is 50-200 g / m 2 , and the grammage of the transition layer is 250-800 g / m 2 . The fiber fineness of the melt-blown layer is 0.5-5 μm, and the fiber fineness of the transition layer is 3.8 dtex. The pore size of the melt-blown layer is 10-20 μm, the pore size of the transition layer is 30-100 μm, and the pore size of the PTFE microporous membrane is 0.1-5 μm, the average pore size is 2 μm, and the thickness is 2-10 μm.

[0027] In the present embodiment, the material of the melt-blown layer is polyester or polypropylene, and the material of the transition layer is one or a combination of dacron, polyphenylene sulfide, polyphenyl sulfone sulfoxide, aramid, polytetrafluoroethylene, polyimide, arsulfonamide, and acrylic.

[0028] As shown in Figure 2 , the present embodiment also provides a filter bag based on the filter material for solid-liquid separation, which is a through-type structure, and is composed of a bag body 11 and bag heads 12 connected to both ends of the bag body 11, and an elastic expanding ring is arranged in the bag head. The bag body 11 and the bag head 12 are both made of the filter material.

[0029] In order to install the filter device applied in the present embodiment, the water inlet layer 1 and the water outlet layer 3 of the filter material are respectively located on the inner and outer sides of the filter bag; the shape and size of the elastic expanding ring are matched with the hole plate of the filter device.

[0030] This embodiment also provides an online regeneration method for the above-mentioned filter bag, the implementation structure of which is as follows: Figure 3 As shown. The method includes:

[0031] 1) Select the needle punching process, hydroentangling process or needle punching and hydroentangling composite process according to the weight of the transition layer substrate, and combine melt-blown technology and hot-pressing coating technology to make filter material; use the filter material to make two bag heads and one bag body, and then sew the three parts together with PTFE stitching to make a filter bag with two through ends.

[0032] In this embodiment, the specific manufacturing method of the filter material is as follows: First, select one of coarse denier fiber needle-punched felt, spunlace felt, or needle-punched and spunlace composite felt, and perform shaping, singeing, and one hot pressing as a transition layer; then, pull the transition layer onto a roller, and use a high-speed hot air flow to extrude polymer melt through the spinneret of a rotating centrifugal die to form ultrafine fibers, which are collected on one side of the transition layer on the roller to form a meltblown layer, and then perform a second hot pressing; finally, perform hot pressing coating treatment on the other side of the transition layer with a PTFE microporous membrane to form a tight and delicate bond between the water outlet layer and the transition layer, thereby producing the filter material.

[0033] The pressure of the natural gas used for singeing is controlled at 0.1-0.5MPa, and the mixing ratio of natural gas and air is 1:1; the temperature of the hot press roller in the hot pressing process is 60-200℃.

[0034] 2) Install several filter bags 101 prepared in step 1) into the housing 102 of the filtration device. The upper and lower bag heads of each filter bag are respectively installed on the upper and lower perforated plates 103 of the housing 102 to keep the filter bag body in a vertical state. The upper opening of the filter bag 101 is connected to the water inlet 104 of the filtration device, and the water outlet 105 of the filtration device is connected to the outer side of the filter bag 101, so that sewage flows into the filter bag 101 through the upper opening of the filter bag 101 and is filtered by its own power. The clean water permeates from the side of the filter bag 101 and is discharged through the water outlet 105.

[0035] 3) The sludge scraping device installed inside the filter bag 101 performs periodic up-and-down reciprocating motion to periodically scrape off the sludge cake on the inner water inlet layer of the filter bag, thereby realizing real-time filtration and online regeneration of the filter bag.

[0036] like Figure 3As shown, the mud scraping device mainly consists of a motor 106, a rotating shaft mechanism, a plurality of spiral steel rings 107, a plurality of pull ropes and a plurality of fixed pulleys 108; the rotating shaft mechanism consists of a rotating shaft 109 horizontally arranged on the upper side of the filter bag in the box and bearing seats 110 at both ends of the rotating shaft 109, the bearing seats 110 are installed on the box 102, and the rotating shaft 109 is driven by the motor 106; one spiral steel ring 107 is arranged in each filter bag 101, and the size of the spiral steel ring 107 is adapted to the inner side of the filter bag 101. The filter bags installed in the filter device are double, and each two filter bags form a group, three pull ropes and a fixed pulley are arranged for each group, the fixed pulley 108 is arranged below the two spiral steel rings 107 in a group, one pull rope 111 is wound around the fixed pulley 108 and connected to the lower ends of the two spiral steel rings 107, and the other two pull ropes 112 are connected to the upper ends of the two spiral steel rings 107 and wound in the wire slot of the rotating shaft 109 in opposite directions, so that when the motor rotates forward or reversely, one pull rope is wound and the corresponding spiral steel ring is lifted upward, the spiral steel ring drags another spiral steel ring downward through the pull rope on the fixed pulley, and a reciprocating mud scraping is formed.

[0037] In the embodiment, the mud scraping device adopts a spring type spiral structure design, the spiral steel ring is a spiral structure formed by rotating a steel wire 5-10 times, and the diameter is preferably 1-3 mm larger than the inner diameter of the filter bag. The shape of the box can be a cylinder, a square, a rectangular, an irregular cube, etc., and the box can be expanded according to the water body, as a sewage reaction tank.

[0038] When working, sewage flows into the filter bag 101 from the water inlet 104, and under the condition of no power source, the sewage is self-driven for filtration by the power of the sewage itself, and part of the sludge adheres to the water inlet layer of the filter bag 101 to form a mud cake. The present application controls the periodic operation of the mud scraping device by automatic technology, controls the mud scraping speed to be 0.1 m / min-3 m / min and the water flux, and periodically reciprocates in the water inlet layer of the filter bag 101 to bring the mud cake into the lower part of the box 102, so as to realize real-time filtration and online regeneration of the filter bag.

[0039] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any person skilled in the art can modify or change the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification made on the basis of the technical essence of the present application to the above embodiments still belongs to the protection scope of the technical solution of the present application.

Claims

1. An on-line regeneration method of a filter bag for solid-liquid separation, characterized by, The application provides a filter material, which comprises a water inlet layer, a transition layer and a water outlet layer which are sequentially stacked together, the water inlet layer is a melt-blown layer, the transition layer is a coarse fiber needle felt, a water jet felt or a needle water jet composite felt, and the water outlet layer is a PTFE microporous membrane; the fiber fineness of the melt-blown layer is 0.5-5 microns, the fiber fineness of the transition layer is 3.8 dtex; the pore size of the melt-blown layer is 10-20 microns, the pore size of the transition layer is 30-100 microns, the pore size of the PTFE microporous membrane is 0.1-5 microns, the average pore size is 2 microns, and the thickness is 2-10 microns; the grammage of the filter material is 300-1000 g / m 2 ; wherein the grammage of the melt-blown layer is 50-200 g / m 2 , and the grammage of the transition layer is 250-800 g / m 2 . The filter bag for solid-liquid separation is of a through-type structure, and is composed of a bag body and bag heads connected to two ends of the bag body, wherein an elastic expanding ring is arranged in the bag head, and the bag body and the bag head are made of the filter material; the water inlet layer and the water outlet layer of the filter material are respectively arranged on the inner side and the outer side of the filter bag; the shape and size of the elastic expanding ring are matched with the hole plate of the filter device; The online regeneration method of the filter bag for solid-liquid separation comprises the following steps: The filter material is made by selecting needle punching process, water jet process or needle punching and water jet composite process according to the basis weight of the transition layer substrate, and combining melt blowing technology and hot pressing film coating technology; the filter material is used to make two bag heads and a bag body, and then the three parts are sewn into a through-type filter bag; A plurality of prepared filter bags are installed in the box of the filter device, the upper and lower bag heads of each filter bag are respectively installed on the upper and lower hole plates of the box to keep the bag body of the filter bag in a vertical state; the upper end opening of the filter bag is communicated with the water inlet of the filter device, and the water outlet of the filter device is communicated with the outer side of the filter bag, so that sewage flows into the filter bag through the upper end opening of the filter bag, and is self-driven for filtration by the self-power of the sewage, and the clean water is discharged from the water outlet. The mud scraping device arranged in the filter bag is periodically reciprocated up and down to periodically scrape the mud cake on the water inlet layer of the inner side of the filter bag, so as to realize real-time filtration and online regeneration of the filter bag. The specific manufacturing method of the filter material is as follows: first, one of coarse denier fiber needle punching felt, water jet felt or needle punching and water jet composite felt is selected, and is subjected to shaping, singeing and first hot pressing and polishing to serve as a transition layer; then, the transition layer is pulled on a roller, high-speed hot air flow is used to extrude polymer melt at the spinning hole of a rotating centrifugal die to form ultrafine fibers on one side of the transition layer on the roller to form a melt blowing layer, and then second hot pressing and polishing are performed; finally, PTFE microporous membrane is hot-pressed and coated on the other side of the transition layer to form a tight and delicate combination between the water outlet layer and the transition layer, so as to manufacture the filter material. The mud scraping device mainly comprises a motor, a rotating shaft mechanism, a plurality of spiral steel rings, a plurality of pull ropes and a plurality of fixed pulleys; the rotating shaft mechanism is composed of a rotating shaft horizontally arranged on the upper side of the filter bag in the box and bearing seats at two ends of the rotating shaft, the bearing seats are installed on the box, and the rotating shaft is driven by the motor; one spiral steel ring is arranged in each filter bag, and the size of the spiral steel ring is adapted to the inner side of the filter bag; the filter device is installed with an even number of filter bags, each two filter bags form a group, three pull ropes and a fixed pulley are provided for each group, the fixed pulley is arranged below the two spiral steel rings in the group, one pull rope is wound around the fixed pulley and connected to the lower ends of the two spiral steel rings, and the other two pull ropes are respectively connected to the upper ends of the two spiral steel rings and wound in the wire slot of the rotating shaft in the opposite direction, so that when the motor is rotated forward or reversely, one pull rope is wound and the corresponding spiral steel ring is lifted upward, the spiral steel ring pulls the other spiral steel ring downward through the pull rope on the fixed pulley, and a reciprocating mud scraping is formed.

2. The method according to claim 1, wherein the filter bag is regenerated on line. The material of the melt-blown layer is polyester or polypropylene, and the material of the transition layer is one or a combination of more than one of polyester, polyphenylene sulfide, polyphenyl sulfone sulfoxide, aramid, polytetrafluoroethylene, polyimide, arsulfro, and acrylic.

3. The method of claim 1, wherein the filter bag is regenerated on-line. The gas pressure for singeing is controlled at 0.1-0.5MPa, and the mixing ratio of gas to air is 1:1; the temperature of the hot calender roller is 60-200℃.

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