Water evaporator and evaporation device

Abstract

This invention discloses a water evaporator and apparatus. The evaporator includes: a primary evaporation unit comprising a primary evaporation chamber, a light-transmitting plate at the upper part of the primary evaporation chamber, and a porous membrane at the lower part of the primary evaporation chamber; and a secondary evaporation unit comprising a light-transmitting sidewall at the periphery and a three-dimensional porous adsorption membrane at the lower part. The porous membrane, the three-dimensional porous adsorption membrane, and the light-transmitting sidewall form the secondary evaporation chamber of the secondary evaporation unit. The water to be treated first enters the primary evaporation chamber of the primary evaporation unit. The water vapor containing VOCs formed by evaporation enters the secondary evaporation chamber of the secondary evaporation unit through the porous membrane at the lower part of the primary evaporation chamber. On the surface of the three-dimensional porous adsorption membrane, the VOCs decompose under the action of a photocatalyst, and then evaporate again under photothermal action and are discharged from the evaporation chamber of the evaporator.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment in environmental engineering, and specifically relates to a water evaporator and evaporation device. Background Technology

[0002] Solar energy is an readily available and clean energy source. Solar-driven evaporation (SE) technology utilizes light-absorbing materials to convert light energy into heat energy in situ, simultaneously heating water and causing evaporation. It has potential applications in industrial water desalination and offers advantages in energy conservation and emission reduction. SE technology has broad application prospects in various fields, including interfacial evaporation for desalination, saline wastewater treatment, and drinking water supply. Interfacial evaporation confines heat energy to a small area at the gas-liquid interface, also known as thermal localization, and is highly efficient in evaporation.

[0003] However, one of the typical characteristics of high-salt industrial wastewater is its extremely high salt content. This directly leads to the localized crystallization and fouling of the membrane by existing membrane-based solar-driven evaporation technology during practical applications, ultimately resulting in a sharp decrease in treatment efficiency. In severe cases, it is necessary to shut down the plant for cleaning, which seriously affects the overall process rhythm and treatment speed of water treatment.

[0004] Furthermore, the high-salinity industrial wastewater often contains volatile organic compounds (VOCs). After evaporation treatment, the condensate is generally reused. However, due to the influence of VOCs, the COD index may not meet the reuse requirements. Therefore, the removal of VOCs in the evaporation and salt separation process deserves attention.

[0005] As mentioned above, although solar-driven evaporation technology can purify and separate non-volatile substances and ionic components, some substances will volatilize due to heating during the evaporation process. In particular, many industrial wastewaters contain a large amount of volatile organic compounds (VOCs), and these volatilized substances cannot be properly and effectively treated. They pass through the membrane pores along with water vapor to the cold side, where they condense into the distillate when they encounter cooling water or cold air, resulting in the inability to obtain high-quality condensate. Summary of the Invention

[0006] 1. The problem to be solved

[0007] To address the problem that existing solar-driven evaporation technologies cannot produce high-quality condensate, this invention provides a water evaporator and evaporation device.

[0008] 2. Technical Solution

[0009] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] The first aspect of the present invention provides a water evaporator and an evaporation device, the evaporator comprising:

[0011] A primary evaporation unit, comprising a primary evaporation chamber, a light-transmitting plate located at the upper part of the primary evaporation chamber, and a porous film located at the lower part of the primary evaporation chamber;

[0012] A secondary evaporation unit includes a light-transmitting sidewall located on the periphery and a three-dimensional porous adsorption membrane located at the bottom; the porous membrane, the three-dimensional porous adsorption membrane, and the light-transmitting sidewall form the secondary evaporation chamber of the secondary evaporation unit;

[0013] in,

[0014] The thickness of the three-dimensional porous adsorption membrane is greater than the thickness of the porous thin film;

[0015] The porous film includes a side facing the primary evaporation chamber and a side facing the secondary evaporation chamber; the side facing the primary evaporation chamber has a light-absorbing material.

[0016] The three-dimensional porous adsorption membrane includes a side facing the secondary evaporation chamber and a side away from the secondary evaporation chamber. The side facing the secondary evaporation chamber is hydrophilic and contains photocatalytic and light-absorbing materials; the side away from the secondary evaporation chamber is hydrophobic.

[0017] As described herein, the water to be treated first enters the primary evaporation chamber of the primary evaporation unit. The water vapor containing VOCs formed by evaporation enters the secondary evaporation chamber of the secondary evaporation unit through the porous membrane at the bottom of the primary evaporation chamber. Under the action of the temperature gradient, the water vapor containing VOCs forms turbulence in the space of the secondary evaporation chamber. The water vapor flows down to the three-dimensional porous adsorption membrane. On the surface of the three-dimensional porous adsorption membrane, VOCs are firmly adsorbed and decomposed under the action of photocatalyst. The water vapor is captured by the hydrophilic components on the surface of the three-dimensional porous adsorption membrane and then evaporates again under the action of photothermal effect and is discharged from the evaporation chamber of the evaporator.

[0018] According to any embodiment of the first aspect of the present invention, the thickness of the porous film is 0.1-2 mm.

[0019] According to any embodiment of the first aspect of the invention, the pore size of the porous film is 0.2-1 μm.

[0020] As described herein, the "porous film" preferably has a relatively ideal service life, and further considering its high light absorption rate, the material of the porous film can be any one or two of PTFE polymer porous film and PVDF polymer porous film.

[0021] In any embodiment of the first aspect of the present invention, further, in order to ensure that the "porous film" has a high light absorption rate (its light absorption rate is greater than 80%), a light-absorbing material can be coated on its surface (especially on the side facing the primary evaporation chamber). Based on this, the light-absorbing material can be any one or two or more of graphite powder, carbon black, carbon nanotubes, and graphene.

[0022] In fact, the side of the porous membrane facing the secondary evaporation chamber is the first point of contact between the secondary evaporation chamber and the water to be treated. In order to reduce the damage caused by the water to be treated to the porous membrane, it is further desirable that the surface of the porous membrane facing the secondary evaporation chamber is also hydrophobic, so as to minimize the possibility or degree of corrosion or blockage of the membrane.

[0023] According to any embodiment of the first aspect of the present invention, the thickness of the three-dimensional porous adsorption membrane is 0.5-3 cm.

[0024] According to any embodiment of the first aspect of the present invention, as previously described, in order to ensure that the "three-dimensional porous adsorption membrane" has a high light absorption rate (its light absorption rate is greater than 80%), a light-absorbing material can be coated on its surface (especially the surface facing the secondary evaporation chamber); accordingly, the light-absorbing material can be any one or two or more of graphite powder, carbon black, carbon nanotubes, and graphene.

[0025] According to any embodiment of the first aspect of the present invention, the "three-dimensional porous adsorption membrane" firstly has a "three-dimensional porous water-permeable framework structure". As mentioned above, in order to ensure that the "three-dimensional porous adsorption membrane" has photocatalytic degradation capability, the "three-dimensional porous adsorption membrane" can be subjected to photocatalytic material loading treatment, so that the surface and / or interior of the "three-dimensional porous adsorption membrane" are loaded with photocatalyst. Based on this, the photocatalytic material can be any one or two or more of TiO2, CeO2, and WS2.

[0026] Furthermore, as described herein, considering that the "three-dimensional porous adsorption membrane" has a certain degree of water absorption, and based on this, combined with the aforementioned thickness requirement (0.5-3 cm), it can increase the residence time of water vapor containing VOCs, ensuring that the VOCs are firmly adsorbed and decomposed under the action of the photocatalyst, without reducing the working efficiency of the evaporator. Therefore, the material of the three-dimensional porous adsorption membrane can be any one or more of melamine sponge, lignocellulose, and polypropylene fiber.

[0027] According to any embodiment of the first aspect of the present invention, the three-dimensional porous adsorption membrane has a photocatalytic material and a light-absorbing material in a mass ratio of (1.5 to 4):1.

[0028] According to any embodiment of the first aspect of the present invention, the working area of ​​the porous film is smaller than the working area of ​​the three-dimensional porous adsorption membrane.

[0029] As described herein, the significance of controlling the water-passing area of ​​the porous membrane to be smaller than that of the three-dimensional porous adsorption membrane, based on the pore size of the porous membrane (0.2-1 μm), lies in the ability to control the turbulence rhythm of water vapor containing VOCs, ultimately controlling the evaporation rate and ensuring the removal effect of VOCs. Furthermore, it is preferable that the water-passing area of ​​the three-dimensional porous adsorption membrane is 2 to 10 times that of the porous membrane.

[0030] According to any embodiment of the first aspect of the present invention, the distance H1 between the porous film and the light-transmitting plate satisfies formula (1):

[0031]

[0032] In the formula:

[0033] H1—The distance between the porous film and the light-transmitting plate, in meters;

[0034] S1—Area of ​​the porous film, m 2 ;

[0035] k—Empirical coefficient, ranging from 0.2 to 1.6;

[0036] C1—TDS value of the water to be treated, g / L;

[0037] W—Average illuminance, kw / m² 2 ;

[0038] T—Temperature of the water to be treated, °C;

[0039] E1—Compensation value, ranging from -1 to 1.

[0040] As described herein, the meaning of the "ratio H1 / S1 of distance H1 to area S1 of porous membrane" is that, under illumination, the porous membrane of the primary evaporation unit absorbs light and heats the water in the primary evaporation chamber. Because the heating capacity of the porous membrane per unit area is limited, if the ratio H1 / S1 is too large, the volume of water heated by the porous membrane per unit area will be too large, resulting in insufficient heat concentration, severe heat dissipation, and reduced evaporation capacity. If the ratio H1 / S1 is too small, the volume of water heated by the porous membrane per unit area will be too small, resulting in an excessively fast evaporation rate, rapid concentration or even local crystallization of saline wastewater, clogging of the porous membrane, and reduced evaporation capacity.

[0041] According to any embodiment of the first aspect of the present invention, the distance H between the porous film and the three-dimensional porous adsorption film satisfies formula (2):

[0042]

[0043] In the formula:

[0044] H—the distance between the porous film and the three-dimensional porous adsorption film, in meters;

[0045] k1—Empirical coefficient, ranging from 0.9 to 1.1;

[0046] S—Area of ​​the three-dimensional porous adsorption membrane, in meters. 2 ;

[0047] k2—Empirical coefficient, ranging from 0.5 to 1.5;

[0048] C—The average VOC concentration of the water to be treated, g / L;

[0049] E—compensation value, ranging from -1 to 1.

[0050] As described herein, the "distance H" is another important factor in controlling the turbulent flow rhythm of water vapor containing VOCs in the secondary evaporation chamber, ultimately controlling the evaporation rate, and ensuring the removal effect of VOCs.

[0051] A second aspect of the present invention provides an evaporation apparatus, the apparatus comprising:

[0052] Evaporator, the evaporator as described in any embodiment of the first aspect of the object of the present invention;

[0053] A condenser is located below the evaporator and is connected to it through a three-dimensional porous adsorption membrane at the bottom of the evaporator.

[0054] According to any embodiment of the second aspect of the present invention, the condenser includes heat sinks and a fan, the fan being positioned close to the three-dimensional porous adsorption membrane. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the evaporator provided in Embodiment 1 of the present invention;

[0056] Figure 2 The porous film of the evaporator provided in Embodiment 1 of the present invention;

[0057] Figure 3 The three-dimensional porous adsorption membrane of the evaporator provided in Embodiment 1 of the present invention;

[0058] Figure 4 This is a schematic diagram of the evaporation apparatus provided in Embodiment 1 of the present invention;

[0059] Figure 5 The condenser of the evaporation apparatus provided in Embodiment 1 of the present invention;

[0060] In the diagram: A. Illumination; B. Evaporation direction; C. Water input; D. Concentrate output; E. Condensate output;

[0061] 100. Evaporator; 110. Primary evaporation unit; 111. Transparent plate; 112. Porous membrane; 112a. Lower side of the porous membrane; 112b. Upper side of the porous membrane; 113. Primary evaporation chamber; 120. Secondary evaporation unit; 121. Three-dimensional porous adsorption membrane; 121a. Upper side of the three-dimensional porous adsorption membrane; 121b. Lower side of the three-dimensional porous adsorption membrane; 123. Transparent sidewall; 124. Secondary evaporation chamber;

[0062] 200. Condenser; 210. Heat sink; 220. Fan. Detailed Implementation

[0063] This disclosure can be more readily understood by referring to the following description in conjunction with examples, all of which form part of this disclosure. It should be understood that this disclosure is not limited to the specific products, methods, conditions, or parameters described and / or shown herein. Furthermore, the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting, unless otherwise stated.

[0064] It should also be understood that, for clarity, certain features of this disclosure may be described herein in the context of individual embodiments, but may also be provided in combination with each other in individual embodiments. That is, unless obviously incompatible or specifically excluded, each individual embodiment is considered to be combinable with any other embodiment, and such combination is considered to represent another different embodiment. Conversely, for brevity, various features of this disclosure described in the context of individual embodiments may also be provided individually or in any sub-combination. Finally, while a particular embodiment may be described as part of a series of steps or part of a more general structure, each step or substructure may also be considered an independent embodiment in itself.

[0065] Unless otherwise stated, it should be understood that each individual element in the list and each combination of individual elements in the list will be interpreted as a different embodiment. For example, a list of embodiments denoted as "A, B, or C" should be interpreted as including embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B, or C".

[0066] In this disclosure, the singular forms of the articles “a,” “one,” and “the” also include the corresponding plural references, and references to a particular value include at least that particular value, unless the context clearly indicates otherwise. Thus, for example, a reference to “substance” is a reference to at least one of such substance and its equivalents.

[0067] Ordinal terms such as “first” and “second” may be used to describe various components or fluids, but these components and fluids are not limited by these terms. Therefore, without departing from the teachings of this disclosure, these terms are used only to distinguish one component / fluid from another.

[0068] When an item is described using the combined terms “...and / or ...", the description should be understood to include any one of the listed items and all combinations thereof.

[0069] Generally, the use of the term "about" indicates an approximation that can vary depending on the desired characteristics obtained from the disclosed subject matter and will be interpreted in a context-dependent manner based on function. Therefore, those skilled in the art will be able to interpret a degree of difference on a case-by-case basis. In some cases, the number of significant figures used when expressing a particular value can be a representative technique for determining the difference allowed by the term "about." In other cases, a gradient within a range of values ​​can be used to determine the range of differences allowed by the term "about." Furthermore, all ranges in this disclosure are inclusive and composable, and references to values ​​described within a range include every value within that range.

[0070] 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 invention pertains; the terms used herein and / or include any and all combinations of one or more of the associated listed items.

[0071] Unless otherwise specified in the following examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0072] The present invention will be further illustrated below with reference to specific embodiments, but these embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. The essential features and significant effects of the present invention can be seen from the following embodiments. The described embodiments are some, but not all, embodiments of the present invention, and therefore do not limit the present invention in any way. Any non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are within the protection scope of the present invention.

[0073] Example 1

[0074] This embodiment provides a water evaporator, which is particularly suitable for the evaporation treatment of saline and VOCs-containing wastewater. For example... Figure 1 As shown, the evaporator 100 includes a primary evaporation unit 110 and a secondary evaporation unit 120; the primary evaporation unit 110 includes a primary evaporation chamber 113, a light-transmitting plate 111 located at the upper part of the primary evaporation chamber 113, and a porous film 112 located at the lower part of the primary evaporation chamber 113; wherein, the material of the light-transmitting plate 111 is preferably selected with good light transmittance, and quartz glass is selected in this embodiment.

[0075] The secondary evaporation unit 120 includes a light-transmitting sidewall 123 located on the periphery and a three-dimensional porous adsorption membrane 121 located at the bottom. The light-transmitting sidewall 123, the porous membrane 112, and the three-dimensional porous adsorption membrane 121 enclose the secondary evaporation chamber 124 of the secondary evaporation unit 120, wherein the thickness of the three-dimensional porous adsorption membrane 121 is greater than the thickness of the porous membrane 112. The light-transmitting sidewall 123 is preferably made of a material with good light transmittance; in this embodiment, quartz glass is selected.

[0076] like Figure 2 As shown, the porous film 112 is coated with a light-absorbing material, giving it a light absorption rate greater than 80% under the solar spectrum; the three-dimensional porous adsorption film 121 is coated with a light-absorbing material, and also supports a photocatalytic material. Furthermore, as... Figure 3 As shown, the side of the three-dimensional porous adsorption membrane 121 facing the secondary evaporation chamber (hereinafter referred to as the upper side 121a of the three-dimensional porous adsorption membrane) is hydrophilic, and the side facing away from the secondary evaporation chamber (hereinafter referred to as the lower side 121b of the three-dimensional porous adsorption membrane) is hydrophobic. The coating of the light-absorbing material onto the porous membrane 112 can be formed and attached to the porous membrane 112 using any existing technology, such as by vacuum filtration-drying (see Master's thesis: Lai Qiaoyun. Research on the Modification of Superhydrophobic Membranes and Their Application in Membrane Distillation Treatment of High-Salinity Wastewater [D]. Guangzhou University, 2023, DOI:10.27040 / d.cnki.ggzdu.2023.001723, Section 3.2.1 Preparation of BC@PVDF Hydrophobic Membrane).

[0077] The coating or loading of the light-absorbing material and photocatalytic material onto the three-dimensional porous adsorption membrane 121 can be achieved using any existing technology to form and adhere them to the porous membrane 112. For example, the three-dimensional porous adsorption membrane 121 can be immersed in a mixture containing the light-absorbing material and photocatalytic material, and after immersion, dried to obtain the three-dimensional porous adsorption membrane 121 with the light-absorbing material and photocatalytic material. Simultaneously, a hydrophilic modifier (such as sodium alginate, sodium carboxymethyl cellulose, chitosan, etc.) can be added to the mixture to simultaneously modify the three-dimensional porous adsorption membrane 121 to obtain a hydrophilic surface. Finally, the lower side 121b of the three-dimensional porous adsorption membrane is subjected to hydrophobic treatment. A possible treatment method is to spray a hydrophobic modifier (such as polydimethylsiloxane, hexadecyltrimethoxysilane, etc.) onto this side to form a single-sided hydrophobic layer. Specifically, in this embodiment:

[0078] The porous film 112 material is selected as a PTFE film, wherein the PTFE film has a pore size of 1 mm, a thickness of 2 mm, and an area of ​​25 cm². 2 The porous film 112 is coated with graphite powder on the side facing the primary evaporation chamber (hereinafter referred to as the upper side 112b of the porous film, and correspondingly, on the side facing the secondary evaporation chamber (hereinafter referred to as the lower side 112a of the porous film) to ensure that the film has a light absorption rate of more than 80% under the solar spectrum.

[0079] The bulk material of the three-dimensional porous adsorption membrane 121 is a 0.5 cm thick melamine sponge, with an area nine times that of the porous film 112 (225 cm²). 2 The three-dimensional porous adsorption membrane 121 is modified as follows:

[0080] (1) Add TiO2 and graphite powder to pure water at a mass ratio of 2.5:1. The mass concentration of graphite powder in the solution is 3 mg / L. Mix thoroughly and sonicate for 30 minutes. Add sodium alginate powder to make the mass concentration of sodium alginate in the solution reach 1 mg / L. Mix thoroughly and sonicate for 30 minutes to obtain the modified solution.

[0081] (2) Immerse the melamine sponge completely in the modification solution for 5 minutes, take it out and place it in a vacuum drying oven at 80°C for 12 hours to obtain the modified melamine sponge.

[0082] (3) Spray polydimethylsiloxane onto one side of the modified melamine sponge at a spraying amount of 1.5 g / m. 2 A single-sided hydrophobic layer is formed, and the three-dimensional porous adsorption membrane 121 used is finally obtained.

[0083] Regarding the distance H1 between the porous film 112 (the upper side 112b of the porous film) and the light-transmitting plate 111 (the surface of the light-transmitting plate 111 facing the primary evaporation chamber), it is calculated as follows:

[0084]

[0085] In the formula:

[0086] S1 takes the value 0.0025m 2 ;

[0087] k takes the value 1.0;

[0088] C1 is 2.5 g / L;

[0089] W is set to 0.8 kW / m 2 ;

[0090] T is set to 30℃;

[0091] E1 takes the value 0.9.

[0092] Based on this, the

[0093] The final H1 / S1 = 1.4.

[0094] Regarding the distance H between the porous film 112 (the lower side 112a surface of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a surface of the three-dimensional porous adsorption film), it is calculated as follows:

[0095]

[0096] In the formula: k1 takes the value 0.9;

[0097] S takes the value 0.225m 2 ;

[0098] k2 takes the value 0.5;

[0099] C takes the value

[0100] E takes the value -0.15.

[0101] Based on this, the final statement

[0102] Based on the above, this embodiment 1 provides a specific evaporator, which will be referred to as evaporator-1 thereafter.

[0103] In addition, the following two types of evaporators are also provided in this embodiment, numbered evaporator-2 and evaporator-3;

[0104] The evaporator-2 is basically the same as the evaporator-1, except that the thickness of its three-dimensional porous adsorption membrane 121 is 1 cm.

[0105] The evaporator-3 is basically the same as the evaporator-1, except that the thickness of its three-dimensional porous adsorption membrane 121 is 3 cm.

[0106] Comparative Example 1

[0107] This comparative example provides the following two types of evaporators, numbered Evaporator-D1 and Evaporator-D2;

[0108] The evaporator-D1 is basically the same as the evaporator-1, except that the three-dimensional porous adsorption membrane 121 used therein only undergoes the modification steps (1) to (2) in Example 1, that is, the polydimethylsiloxane spraying in step (3) is no longer performed.

[0109] The evaporator-D2 is basically the same as the evaporator-1, except that when the three-dimensional porous adsorption membrane 121 used therein is modified according to steps (1) to (3) in Example 1, sodium alginate powder is no longer added to the modification solution in step (1) for hydrophilic modification.

[0110] Comparative Example 2

[0111] This comparative example provides the following two types of evaporators, numbered from Evaporator-D3 to Evaporator-D5;

[0112] The evaporator-D3 is basically the same as the evaporator-1, except that the distance H between the porous film 112 (the lower side 112a of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a of the three-dimensional porous adsorption film) is set to 1 cm.

[0113] The evaporator-D4 is basically the same as the evaporator-1, except that the distance H between the porous film 112 (the lower side 112a of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a of the three-dimensional porous adsorption film) is set to 5cm.

[0114] The evaporator-D5 is basically the same as the evaporator-1, except that the distance H between the porous film 112 (the lower side 112a of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a of the three-dimensional porous adsorption film) is set to 15cm.

[0115] Comparative Example 3

[0116] This comparative example provides the following two types of comparative evaporators, numbered from Evaporator-D6 to Evaporator-D7;

[0117] The evaporator-D6 is basically the same as the evaporator-1, except that the thickness of its three-dimensional porous adsorption membrane 121 is 0.2 cm.

[0118] The evaporator-D7 is basically the same as the evaporator-1, except that the thickness of its three-dimensional porous adsorption membrane 121 is 5 cm.

[0119] Comparative Example 4

[0120] This comparative example provides the following comparison evaporator, numbered Evaporator-D8;

[0121] The evaporator-D8 is basically the same as the evaporator-1, except that its three-dimensional porous adsorption membrane 121 is a glass fiber membrane that does not have adsorption properties.

[0122] Comparative Example 5

[0123] This comparative example provides the following comparative evaporators, numbered from evaporator-D9 to evaporator-D12;

[0124] The evaporator-D9 is basically the same as the evaporator-1, except that the distance H1 between the porous film 112 (the upper side 112b of the porous film) and the light-transmitting plate 111 (the surface of the light-transmitting plate 111 facing the primary evaporation chamber) is set to 3.5 cm. Based on this, the final H1 / S1 = 14.

[0125] The evaporator-D10 is basically the same as the evaporator-1, except that the distance H1 between the porous film 112 (the upper side 112b of the porous film) and the light-transmitting plate 111 (the surface of the light-transmitting plate 111 facing the primary evaporation chamber) is set to 10.5 mm. Based on this, the final H1 / S1 = 4.2.

[0126] The evaporator-D11 is basically the same as the evaporator-1, except that the distance H1 between the porous film 112 (the upper side 112b of the porous film) and the light-transmitting plate 111 (the surface of the light-transmitting plate 111 facing the primary evaporation chamber) is set to 7 mm. Based on this, the final H1 / S1 = 2.8.

[0127] The evaporator-D12 is basically the same as the evaporator-1, except that the distance H1 between the porous film 112 (the upper side 112b of the porous film) and the light-transmitting plate 111 (the surface of the light-transmitting plate 111 facing the primary evaporation chamber) is set to 2 mm. Based on this, the final H1 / S1 = 0.8.

[0128] Example 2

[0129] This embodiment provides an evaporation device, such as... Figure 4As shown, the evaporation device includes an evaporator 100 and a condenser 200.

[0130] The condenser 200 is located below the evaporator 100 and is connected through a three-dimensional porous adsorption membrane 121 at the bottom of the evaporator 100.

[0131] The main function of the condenser 200 is to condense and collect the water vapor discharged from the three-dimensional porous adsorption membrane 121 after processing by the evaporator 100. Theoretically, the condenser 200 can be any commercially available form. However, considering the improvement of water vapor turbulence within the evaporation chamber 140, a condenser with a fan is preferred. Specifically, in this embodiment, as... Figure 5 As shown, the condenser 200 includes a housing, a heat sink 210 and a fan 220 located inside the housing, and the fan 220 is positioned close to the three-dimensional porous adsorption membrane 121 directly below it.

[0132] Based on the evaporators-1 to-3 provided in Example 1, this example forms corresponding evaporation devices 1 to 3.

[0133] Comparative Example 6

[0134] Based on the evaporators D1 to D12 provided in Comparative Examples 1 to 5 above, this comparative example forms an evaporation apparatus D1 to D12 that is basically the same as that in Example 2.

[0135] Example 3

[0136] This embodiment utilizes evaporation devices 1-3 provided in Embodiment 2 and evaporation devices D1-D7 provided in Comparative Example 5 to treat the water body to be treated (high-salt wastewater from a chemical plant). The local area has abundant sunshine, with an average daytime light intensity of 0.8 kW / m². 2 The wastewater had an average temperature of 30℃, a total dissolved solids (TDS) of 25000 mg / L, a COD of 400 mg / L, and VOCs of 50 mg / L, with the VOCs mainly being phenols. The effects before and after treatment during 7 consecutive days of operation (6 hours per day) are shown in Table 1.

[0137] Table 1:

[0138]

[0139]

[0140] As can be seen from Table 1:

[0141] (1) As can be seen from the combination of evaporation device 1 to evaporation device 3, the water production rate of the three-dimensional porous adsorption membrane 121 decreases slightly with the increase of thickness in the range of 0.5-3cm, but TDS, VOCs and other indicators are not detected, and the removal effect is good.

[0142] Further, in conjunction with the evaporation device-D6, it can be seen that if the thickness of the three-dimensional porous adsorption membrane 121 is too small, the adsorption capacity will be poor, and a large amount of VOCs will permeate, resulting in substandard water production. In conjunction with the evaporation device-D7, it can be seen that if the thickness of the three-dimensional porous adsorption membrane 121 is too large, the turbulence state will change, the steam flow resistance will increase, and the evaporation rate will decrease.

[0143] (2) Combining evaporator 1 and evaporator-D1, it can be seen that the lower side 121b surface of the three-dimensional porous adsorption membrane is no longer coated with polydimethylsiloxane in step (3), which will affect the removal effect of VOCs and cause a significant decrease in condensate production. The reason is:

[0144] Firstly, the three-dimensional porous adsorption membrane 121 no longer has a hydrophilic-hydrophobic two-sided structure, and the upper and lower sides are fully hydrophilic, which leads to a reduction in the heat localization effect and a slight decrease in condensate production.

[0145] Secondly, the contact interface between the adjacent contact areas of the evaporator 100 and the condenser 200 changes from hydrophobic to hydrophilic. This hydrophilic contact alters the evaporation-adsorption cycle in this area, hindering the unidirectional transport of water vapor from the evaporator 100 area to the condenser 200 area. The stronger the hydrophilicity of the lower side 121b of the three-dimensional porous adsorption membrane, the more rapidly some VOCs carried by the water vapor will transfer along the internal channels of the three-dimensional porous adsorption membrane 121 into the condenser 200, reducing the residence time of VOCs within the three-dimensional porous adsorption membrane 121 and resulting in insufficient catalytic degradation.

[0146] (3) As can be seen from the combination of evaporation device 1 and evaporation device-D2, the three-dimensional porous adsorption membrane 121 no longer undergoes hydrophilic treatment, which affects the removal effect of VOCs and causes a slight decrease in condensate production. The reason is:

[0147] In particular, the hydrophilicity of the upper side 121a of the three-dimensional porous adsorption membrane is reduced, which reduces the absorption rate of water vapor in the evaporation chamber 140 by the three-dimensional porous adsorption membrane 121. At the same time, the adsorption capacity of VOCs is reduced, resulting in a decrease in the water production rate and the water produced contains VOCs.

[0148] (4) The suction effect of the condenser 200 fan 220 will affect the airflow circulation. As can be seen from the combination of evaporator 1, evaporator-D3, and evaporator-D4, if the distance H between the porous film 112 (the lower side 112a surface of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a surface of the three-dimensional porous adsorption film) is too small, the evaporation chamber 140 will be strongly affected by the airflow circulation of the condenser 200 fan 220, which will weaken the heat storage effect of the evaporation chamber 140 and affect the steam output of the evaporator 100.

[0149] In addition, the temperature in the condenser zone 200 will be higher due to the circulation of the fan, which will affect the condensation effect.

[0150] Furthermore, due to the airflow circulation, the contact time between VOCs and the catalyst is greatly reduced, causing them to directly enter the condensate and affecting VOCs removal.

[0151] As can be seen from the combination of evaporation device 1 and evaporation device-D5, if the distance H between the porous film 112 (the lower side 112a surface of the porous film) and the three-dimensional porous adsorption film 121 (the upper side 121a surface of the three-dimensional porous adsorption film) is too large, it will result in an excessively large heat storage area, making it difficult to maintain a stable thermal cycle under turbulent flow, thus reducing the water production rate.

[0152] (5) Combining the evaporation device 1 and the evaporation device-D8, it can be seen that the body of the three-dimensional porous adsorption membrane 121 no longer has water absorption properties, which will affect the water production rate. The body no longer has water absorption properties, which leads to the shrinkage of the hydrophilic transport channel. The hydrophilic channel composed of modified materials alone is obviously insufficient for the absorption and transport of water vapor, resulting in a decrease in the overall water production rate of the device.

[0153] (6) Combining evaporator 1, evaporator-D9, evaporator-D10, and evaporator-D11, it can be seen that if the ratio H1 / S1 is too large, the output of condensate will decrease significantly. The reason is that the volume of water heated by the porous film per unit area is too large, resulting in insufficient heat concentration, poor heat localization effect, serious heat dissipation, and reduced evaporation capacity.

[0154] Based on the analysis of evaporation units 1 and evaporation unit-D12, it can be seen that if the ratio H1 / S1 is too small, it will lead to supersaturation of the brine, resulting in crystal precipitation. Long-term operation will scratch and damage the porous membrane, causing localized minor damage and resulting in substandard conductivity of the produced water. Furthermore, the brine crystal particles block the water transport channels and obscure the light-absorbing layer of the porous membrane, significantly reducing the evaporation rate.

[0155] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water evaporator, characterized in that, The evaporator includes: A primary evaporation unit, comprising a primary evaporation chamber, a light-transmitting plate located at the upper part of the primary evaporation chamber, and a porous film located at the lower part of the primary evaporation chamber; A secondary evaporation unit includes a light-transmitting sidewall located on the periphery and a three-dimensional porous adsorption membrane located at the bottom; the porous membrane, the three-dimensional porous adsorption membrane, and the light-transmitting sidewall form the secondary evaporation chamber of the secondary evaporation unit; in, The thickness of the three-dimensional porous adsorption membrane is greater than the thickness of the porous thin film; The porous film includes a side facing the primary evaporation chamber and a side facing the secondary evaporation chamber; the side facing the primary evaporation chamber has a light-absorbing material. The three-dimensional porous adsorption membrane includes a side facing the secondary evaporation chamber and a side away from the secondary evaporation chamber. The side facing the secondary evaporation chamber is hydrophilic and contains photocatalytic and light-absorbing materials; the side away from the secondary evaporation chamber is hydrophobic. The distance H between the porous film and the three-dimensional porous adsorption film satisfies formula (2): （2） In the formula: H—the distance between the porous film and the three-dimensional porous adsorption film, in meters; k1—Empirical coefficient, ranging from 0.9 to 1.1; S—Area of ​​the three-dimensional porous adsorption membrane, in meters. 2 ; k2—Empirical coefficient, ranging from 0.5 to 1.5; C—The average VOC concentration of the water to be treated, g / L; E—Compensation value, ranging from -1 to 1.

2. The water evaporator according to claim 1, characterized in that, The thickness of the porous film is 0.1-2 mm; And / or, The thickness of the three-dimensional porous adsorption membrane is 0.5-3 cm.

3. The water evaporator according to claim 1, characterized in that, The distance H1 between the porous film and the light-transmitting plate satisfies formula (1): （1） In the formula: H1—The distance between the porous film and the light-transmitting plate, in meters; S1—Area of ​​the porous film, m 2 ; k—Empirical coefficient, ranging from 0.2 to 1.6; C1—TDS value of the water to be treated, g / L; W—Average illuminance, kw / m² 2 ; T—Temperature of the water to be treated, °C; E1—Compensation value, ranging from -1 to 1.

4. The water evaporator according to any one of claims 1 to 3, characterized in that, The working area of ​​the porous film is smaller than that of the three-dimensional porous adsorption film.

5. The water evaporator according to claim 4, characterized in that, The working area of ​​the three-dimensional porous adsorption membrane is 2 to 10 times that of the porous thin film.

6. The water evaporator according to claim 4, characterized in that, The porous film is selected from any one or two of PTFE polymer porous films and PVDF polymer porous films. The material of the three-dimensional porous adsorption membrane is selected from any one or two or more of melamine sponge, lignocellulose, and polypropylene fiber.

7. The water evaporator according to any one of claims 1 to 3, characterized in that, The three-dimensional porous adsorption membrane contains photocatalytic material and light-absorbing material in a mass ratio of (1.5~4):

1.

8. A water evaporation device, characterized in that, The device includes: Evaporator, as described in any one of claims 1 to 7; A condenser is located below the evaporator and is connected to it through a three-dimensional porous adsorption membrane at the bottom of the evaporator.

9. The water evaporation device according to claim 8, characterized in that, The condenser includes heat sinks and a fan, with the fan positioned close to the three-dimensional porous adsorption membrane.

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