Preparation method of rigid renewable adsorption functional interlayer filter element

Abstract

The invention provides a preparation method of a rigid renewable adsorption functional interlayer filter element, and belongs to the technical field of filtering devices. The preparation method comprises the following steps: filling ultrahigh molecular weight plastic powder as a raw material into a mold, sintering, cooling and demolding to obtain a double-layer filter body, filling granular active carbon into the double-layer filter body, compacting to form an active carbon adsorption layer, filling the ultrahigh molecular weight plastic powder at a seal, sintering for the second time, cooling and demolding to obtain the interlayer filter element. The double rigid filter layers are filled with granular activated carbon with the filter precision larger than 0.2 mu m. The double-layer rigid filter body obtained after high-temperature sintering is filled with the granular activated carbon, materials needing to be decolored can make uniform and sufficient contact with the activated carbon, the materials can be directly decolored, decoloring is efficient and stable, the activated carbon material and the stirring process are not needed, the production environment is greatly improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of filtering devices, and in particular to a method for preparing a rigid regenerable adsorption functional sandwich filter element. Background Art

[0002] Activated carbon decolorization is a physical and chemical process based on the porous structure of activated carbon to adsorb pigments and organic impurities in the solution. It is widely used in food, pharmaceutical and chemical industries.

[0003] The process involves thoroughly stirring the activated carbon with the solution to be decolorized for a specific period of time, followed by removal of the activated carbon from the liquid material by filtration.

[0004] Its key equipment includes mixing tanks, material pipelines, cleaning water pipelines and filtration equipment.

[0005] The main process flow is: feeding, stirring, filtering, collecting filter residue, and cleaning filtering equipment and pipelines.

[0006] The activated carbon used in the above process is in the form of a black powder. The addition and mixing steps easily generate dust, significantly impacting workshop air quality. Furthermore, collecting activated carbon filter residue and cleaning the filtration equipment and pipes requires a large amount of clean water for flushing. The resulting flushing water contains a high concentration of black activated carbon powder and must be treated before discharge. The entire process significantly pollutes the workshop environment and incurs high wastewater treatment costs. Summary of the Invention

[0007] In view of this, in order to solve the shortcomings described in the background technology of traditional activated carbon decolorization, the present invention provides a method for preparing a rigid, regenerable adsorption functional sandwich filter element. The double-layer rigid filter body obtained after high-temperature sintering is filled with granular activated carbon with a filtration accuracy of >0.2μm. The material to be decolorized can be evenly and fully contacted with the activated carbon, and the material can directly achieve the purpose of decolorization. The decolorization is efficient and stable, and there is no need to add activated carbon material and stirring process, which greatly improves the production environment and reduces production costs.

[0008] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a method for preparing a rigid, regenerable adsorption functional sandwich filter element, the sandwich filter element comprising: A double-layer filter body, which consists of an inner filter layer (2) and an outer filter layer (1), wherein the double-layer filter body is obtained by sintering ultra-high molecular weight plastic powder at high temperature; An activated carbon adsorption layer (3) filled with granular activated carbon having a particle diameter greater than 0.2 μm; The preparation method specifically comprises the following steps: Preparation of double-layer filter: Ultra-high molecular weight plastic powder is used as raw material and loaded into a mold for sintering, and then cooled and demoulded to obtain a double-layer filter; Filling of activated carbon adsorption layer (3): Filling granular activated carbon into the double-layer filter body and vibrating it; Secondary sintering: Fill the sealing part with ultra-high molecular weight plastic powder, perform the second sintering, and then cool and demould to obtain the sandwich filter element.

[0009] Preferably, the ultra-high molecular weight plastic powder is at least one of polyethylene, polypropylene, and nylon.

[0010] Preferably, the high-temperature sintering temperature is 150-250° C., and the sintering time is 30-240 minutes.

[0011] Preferably, the particle size of the ultra-high molecular weight plastic powder is in the range of 1-30 μm.

[0012] Preferably, the molecular weight of the ultra-high molecular weight plastic powder is 700,000-1.5 million.

[0013] Preferably, during the preparation of the double-layer filter, the packing density of the ultra-high molecular weight plastic powder is 0.4-0.7.

[0014] Preferably, the mold is a U-shaped tubular mold.

[0015] Preferably, the secondary sintering temperature is 120-180° C., and the sintering time is 20-80 min.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) Significantly improve the production environment and eliminate potential pollution hazards Fully encapsulated activated carbon design: The activated carbon is locked inside the filter element through a double-layer polymer sintered filter layer (the inner and outer layers are preferably 5mm thick, with a filtration accuracy of 0.2μm), ensuring that the activated carbon particles (minimum particle size > 0.2μm) cannot leak.

[0017] Eliminate the mixing and feeding steps: No need to feed activated carbon powder and stir the activated carbon in the traditional process, thus avoiding dust pollution; at the same time, there is no need to clean the residual activated carbon in the pipeline, thus reducing the use of clean water.

[0018] Advantages: The workshop does not need to isolate the decolorization section, and the cleanliness is greatly improved; Avoid the impact of activated carbon dust on air quality and reduce health risks for operators; Reduce the generation of wastewater containing activated carbon and reduce the cost of wastewater treatment.

[0019] (2) Simplify the process flow and reduce equipment maintenance costs Integrated filter element structure: Integrates filtration and adsorption functions, replacing the traditional complex system of "stirring tank + filtration equipment", eliminating the stirring device and related pipelines.

[0020] Reduce equipment investment (no need for mixing tank) and floor space; Simplify the operation steps (for example, after a pharmaceutical factory in Zhejiang Province adopted the filter element of the present invention in the glucose syrup decolorization process, the stirring tank and the activated carbon injection process were eliminated, thus avoiding activated carbon dust. The decolorization section was not used to isolate other sections in the workshop, and the process of cleaning the residual activated carbon in the filtration equipment and pipelines was also eliminated. The cleanliness and environment of the workshop were greatly improved, and the filter element only needed to be replaced every two weeks); The filter element replacement cycle is as long as half a month, the maintenance frequency is low, and the labor cost is reduced.

[0021] (3) The filter element can be recycled and reused to improve economy and durability Selection of rigid polymer materials: The filter layer is made of rigid materials such as polyethylene and polypropylene, which can withstand 0.6MPa backflushing pressure and can be regenerated and reused by physical backflushing method.

[0022] Physical backflushing regeneration mechanism: After adsorption saturation, backflushing is used to remove adsorbents on the surface of activated carbon, allowing the filter element to be reused.

[0023] Advantages: Avoid the waste of disposable consumables of traditional activated carbon and reduce operating costs; The rigid structure is impact-resistant and wear-resistant, with a long service life and reduced replacement frequency.

[0024] (4) High and stable decolorization efficiency to ensure product quality Optimized design of activated carbon interlayer: The thickness of the activated carbon adsorption layer is preferably 20mm, matching the filtration accuracy of 0.2μm, to ensure uniform penetration of the material and full contact with the activated carbon, thereby improving adsorption efficiency.

[0025] Particle diameter control: Activated carbon particles are screened by a laser particle size analyzer (minimum particle size > 0.2 μm) to avoid clogging the filter layer while ensuring the adsorption area.

[0026] Advantages: The decolorization effect is stable, the material is in full contact with the activated carbon, and the removal rate of pigments and organic impurities is high; The pore size of the filter layer is uniform and the flow rate is stable, avoiding the fluctuation of filtration efficiency caused by activated carbon deposition in traditional processes.

[0027] In summary, through the synergistic effect of the above-mentioned technical means, the present invention achieves the comprehensive advantages of "environmental protection, high efficiency, low cost, and easy maintenance", and solves the core pain points of the traditional activated carbon decolorization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention; In the figure, 1. Outer filter layer; 2. Inner filter layer; 3. Activated carbon adsorption layer. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "mounted / connected," and "connected" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention in specific circumstances.

[0032] like Figure 1 As shown, the present invention provides a rigid regenerable adsorption functional sandwich filter element, comprising: The double-layer filter element comprises an inner filter layer 2 and an outer filter layer 1 (both preferably 5 mm thick). The double-layer filter element is formed by high-temperature sintering of ultra-high molecular weight plastic powder. In the present invention, the ultra-high molecular weight plastic powder is preferably at least one of polyethylene, polypropylene, and nylon, with the polyethylene preferably being high-density polyethylene or ultra-high molecular weight polyethylene. Its particle size preferably ranges from 1 to 30 μm, and its molecular weight preferably ranges from 700,000 to 1.5 million. The high-temperature sintering temperature is preferably 150-250°C, and the sintering time is preferably 30-240 minutes. After high-temperature sintering, the double-layer filter element forms a rigid filter layer.

[0033] The essence of polymer powder sintered microporous materials is the process of "surface melting-particle bonding-pore fixation".

[0034] Therefore, the core principle of the present invention is that the surface of ultra-high molecular weight plastic powder particles softens and bonds at sub-melting temperature, micropores are formed in the stacking gaps, and the structure is stabilized through diffusion and densification.

[0035] Specifically in the present invention: Ultra-high molecular weight polyethylene has a high melt index and can maintain a semi-molten state within a wide temperature range. Ultra-high molecular weight polyethylene is generally used as the main sintering material.

[0036] Polyethylene, high-density polyethylene, polypropylene, and nylon are added in small amounts as sintering connectors to increase the connection strength of microporous materials. At the same time, their addition ratio is also used as one of the methods to regulate pore size and porosity.

[0037] Regarding rigidity: compared with flexible filter materials such as filter cloth, filter membrane, and filter paper, the polymer sintered microporous material used in the present invention is rigid, not easy to break or rupture, stable and durable, and more adaptable to various complex industrial filtration environments. Specifically, the advantage of the present invention is that it can fix the powdered activated carbon in the interlayer, is resistant to high-pressure backflushing and backwashing, is not easy to deform or break, has better uniformity and consistency, and does not leak carbon.

[0038] The activated carbon adsorption layer 3 is filled with granular activated carbon with a particle diameter greater than 0.2 μm (tested by a laser particle size analyzer, with a minimum particle diameter greater than 0.2 μm). The thickness of the activated carbon adsorption layer 3 filled with granular activated carbon is preferably 20 mm. The activated carbon prevents leakage. Through a circulating filtration process, the material to be decolorized evenly passes through the activated carbon within the interlayer, ensuring uniform and sufficient contact with the activated carbon. The material is directly decolorized, utilizing the porous structure of the activated carbon to adsorb pigments and organic impurities, achieving efficient decolorization without the need for activated carbon feed and stirring.

[0039] Activated carbon encapsulation and leakage prevention: The inner and outer filter layers lock the activated carbon to prevent it from leaking into the solution or pipeline, preventing contamination of equipment and pipelines.

[0040] Simplified process flow: No need for stirring device and activated carbon feeding steps in traditional process, decolorization is completed directly through circulation filtration.

[0041] The outer diameter of the filter element provided by the present invention is preferably φ80mm, the inner diameter is preferably φ30mm, and the length can be customized according to actual needs.

[0042] In the present invention, during the preparation of the double-layer filter, the packing density of the ultra-high molecular weight plastic powder is 0.4-0.7.

[0043] To this end, the present invention provides a method for preparing the above-mentioned rigid regenerable adsorption functional sandwich filter element, which specifically comprises the following steps: Preparation of double-layer filter: Ultra-high molecular weight plastic powder is used as raw material and loaded into a mold for sintering, and then cooled and demoulded to obtain a double-layer filter; Filling of activated carbon adsorption layer 3: Filling the granular activated carbon into the double-layer filter body and vibrating it; Secondary sintering: Fill the sealing part with ultra-high molecular weight plastic powder, perform the second sintering, and then cool and demould to obtain the sandwich filter element.

[0044] In this preparation method, it is necessary to precisely control the sintering temperature and time, strictly control the above-mentioned semi-molten state, and obtain the microporous material after cooling.

[0045] In this invention, the mold is a U-shaped tubular mold. The raw material is loaded into the mold, and the mold's geometry directly determines the macroscopic morphology after sintering. The U-shaped tubular design naturally forms a double-layer concentric structure: an inner layer (tubular inner wall) and an outer layer (tubular outer wall). When the powder is filled into the mold, the inner and outer diameters are precisely defined by the mold (corresponding to φ80 x φ30 mm for the finished filter element). After sintering, cooling and demolding maintain the double-layer tubular shape, resulting in a double-layer filter element.

[0046] The bonding characteristics of powder sintering are as follows: When ultra-high molecular weight plastic powder (particle size 1-30μm) is melted at 150-250℃, it does not completely liquefy into a fluid, but forms a continuous structure through the melting and bonding between particles. The packing density (0.4-0.7) controls the gaps between the powder particles, ensuring that a porous skeleton is formed between the particles after melting (rather than a dense body). At the same time, the constraint of the mold allows the inner and outer layers to be formed simultaneously, ultimately forming a double-layer filter. In the present invention, the secondary sintering temperature is 120-180° C., and the sintering time is 20-80 minutes.

[0047] The above preparation method may specifically be: Preparation of double-layer filter body: ultra-high molecular weight plastic powder with a particle size range of 1-30μm is used as raw material, dried and loaded into a U-shaped tubular mold for sintering, with a packing density of 0.4-0.7, a sintering temperature of 150-250℃, a constant temperature sintering time of 30-240 minutes, and cooling and demolding to obtain a double-layer filter body.

[0048] Filling the activated carbon adsorption layer 3: The activated carbon needs to be tested with a laser particle size instrument to determine that its minimum particle diameter is greater than 0.2μm. Use a special carbon addition funnel to quantitatively load the activated carbon into the double-layer filter body and vibrate the activated carbon.

[0049] Secondary Sintering: First, seal the mold and fill it with ultra-high molecular weight plastic powder (molecular weight 700,000-1.5 million). Compact the mold with a dedicated press. Then, perform a second sintering process at a temperature of 120-180°C for 20-80 minutes. Finally, cool and demold the mold to obtain the sandwich filter element.

[0050] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical scope disclosed in the present invention and who makes equivalent substitutions or modifications based on the technical solution of the present invention and its improved concepts shall be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a rigid, regenerable adsorption-functional sandwich filter element, the sandwich filter element comprising: A double-layer filter body, which consists of an inner filter layer (2) and an outer filter layer (1), wherein the double-layer filter body is obtained by sintering ultra-high molecular weight plastic powder at high temperature; An activated carbon adsorption layer (3) filled with granular activated carbon having a particle diameter greater than 0.2 μm; It is characterized in that the preparation method specifically comprises the following steps: Preparation of double-layer filter: Ultra-high molecular weight plastic powder is used as raw material and loaded into a mold for sintering, and then cooled and demoulded to obtain a double-layer filter; Filling of activated carbon adsorption layer (3): Filling granular activated carbon into the double-layer filter body and vibrating it; Secondary sintering: Fill the sealing part with ultra-high molecular weight plastic powder, perform the second sintering, and then cool and demould to obtain the sandwich filter element.

2. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: The ultra-high molecular weight plastic powder is at least one of polyethylene, polypropylene and nylon.

3. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: The high temperature sintering temperature is 150-250°C, and the sintering time is 30-240 minutes.

4. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: The particle size range of ultra-high molecular weight plastic powder is 1-30μm.

5. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: The molecular weight of ultra-high molecular weight plastic powder is 700,000-1.5 million.

6. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: During the preparation of the double-layer filter, the packing density of the ultra-high molecular weight plastic powder is 0.4-0.

7.

7. The method for preparing a rigid regenerable adsorption functional sandwich filter element according to claim 1, characterized in that: The mold is a U-shaped tubular mold.

8. A method for preparing a rigid regenerable adsorption functional sandwich filter element according to any one of claims 1 to 7, characterized in that: The secondary sintering temperature is 120-180°C, and the sintering time is 20-80 minutes.

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