CN217709267U

CN217709267U - W-shaped alumina supported silicon carbide ceramic membrane

Info

Publication number: CN217709267U
Application number: CN202221771697.9U
Authority: CN
Inventors: 吴海; 陈金国; 张伟
Original assignee: Shanghai Panda Machinery Group Co Ltd
Current assignee: Shanghai Panda Machinery Group Co Ltd
Priority date: 2022-07-10
Filing date: 2022-07-10
Publication date: 2022-11-01
Anticipated expiration: 2032-07-10

Abstract

The utility model relates to a W type alumina supports carborundum ceramic membrane, be the aluminium oxide supporter of W type or zigzag and coat in the carborundum film on aluminium oxide supporter surface including surface geometry. The geometric shape of the surface of the ceramic membrane is W-shaped (or zigzag), so that the material consumption and sintering cost are not increased, and the membrane area is increased to 2 times under the condition of similar loading density; the hydrophilicity and the permeation efficiency of the ceramic membrane are greatly improved, and the cost of using the ceramic membrane in the water treatment field is obviously reduced.

Description

W-type alumina supported silicon carbide ceramic membrane

Technical Field

The utility model belongs to the inorganic membrane field, in particular to W type aluminium oxide supports carborundum ceramic membrane.

Background

The development of inorganic membrane separation technology began in the forties of the 20 th century, and after the last 60 th century, the inorganic membrane separation technology was widely applied to various fields such as food, medicine, biology, chemical engineering, metallurgy, energy, petroleum, water treatment and the like, and has become one of the most important separation means.

Inorganic separation membranes based on ceramic membranes have incomparable advantages over polymeric separation membranes, such as: the chemical stability is good, the acid and alkali resistance can be realized, the organic solvent resistance can be realized, and no harmful substance is separated out; the mechanical strength is high, and the cleaning agent is suitable for various physical cleaning; the antimicrobial capacity is strong, and the antimicrobial agent does not react with microorganisms; good hydrophilicity, high separation efficiency and the like. And belongs to an environment-friendly material.

In terms of shape, most of ceramic separation membranes produced at home and abroad are tubular ceramic membranes and flat ceramic membranes. The short plates of the tubular ceramic membrane are: low packing density, difficult regeneration and high energy consumption caused by large transmembrane pressure difference. These disadvantages limit the large area application of tubular ceramic membranes in more fields. The flat ceramic membranes which have appeared in recent years have integrated the advantages of flat polymeric membranes and tubular ceramic membranes and have been widely used in a variety of fields including water treatment.

The main materials used for the ceramic membrane mainly comprise alumina, zirconia, titania and silicon carbide, and the ceramic membrane generally has two or more asymmetric structures, namely a separation layer for separation, a transition layer and a support layer for support, observed from the perspective of an enlarged cross section. The support layer is used for increasing the mechanical strength of the membrane and has to have a proper pore size and porosity to increase the permeability. The support layer determines the shape and packing pattern of the ceramic membrane. The separation layer is a membrane layer, and is loaded on the support layer or the transition layer by various methods, the separation process mainly occurs on the membrane layer, and the surface characteristics of the separation membrane play a key role in the separation precision and the separation efficiency of the ceramic membrane.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that the surface area of the existing flat ceramic membrane is limited by cost and has poor permeation efficiency. Therefore, the W-shaped alumina supported silicon carbide ceramic membrane is provided, the hydrophilicity and the permeation efficiency of the ceramic membrane are greatly improved, and the cost of using the ceramic membrane in the water treatment field is obviously reduced.

The utility model provides a W type alumina supports silicon carbide ceramic membrane, be the alumina supporter of W type or zigzag and coat in the silicon carbide film on alumina supporter surface including the surface geometry.

The inner channel of the alumina support body is of a diamond structure. The diamond-shaped structure has a transverse width of 500mm or less and an angle of 45-90 deg., preferably 60 deg. between the bottom and the top.

Preferably, the alumina support comprises a closed end and a water passing end; wherein, the closed end is sealed by adopting alumina integrated forming.

Advantageous effects

(1) The geometric shape of the surface of the ceramic membrane is W-shaped (or zigzag), so that the material consumption and sintering cost are not increased, and the membrane area is increased to 2 times under the condition of similar loading density;

(2) The utility model discloses the rhombus structure of passageway in the ceramic membrane, the rete adds the supporting layer thickness and all is equal on every point, namely the osmotic resistance of every point has the uniformity, is convenient for realize the homogeneity of membrane backwash;

(3) The material of the film layer of the ceramic film is silicon carbide, and the hydrophilicity of the silicon carbide is superior to that of the aluminum oxide, so that the pure water flux of the silicon carbide film layer is 1.5-3 times of that of the aluminum oxide film layer;

(4) The ceramic membrane of the utility model has a porosity of 30-50% and an average pore diameter of 100nm, which greatly improves the hydrophilicity of the ceramic membrane, and the pure water flux is 2-3m³·m^-2·h^-1·bar^-1The flexural strength is more than 35MPa, the compressive strength is more than 80MPa, and the method has good market application prospect.

(5) The utility model discloses a vertical rupture strength of W type (or zigzag) ceramic membrane compares and improves 20% -30% in common dull and stereotyped ceramic membrane.

(6) The utility model discloses a single-ended confined structure of ceramic membrane has reduced the cost of secondary encapsulation, has promoted the use reliability of membrane simultaneously.

Drawings

FIG. 1 is a schematic view of a mold used for the ceramic membrane support of the present invention;

FIG. 2 is a schematic view of a W-shaped alumina-supported silicon carbide ceramic membrane according to the present invention;

FIG. 3 is a second schematic view of a W-shaped alumina supported silicon carbide ceramic membrane according to the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes or modifications can be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.

Example 1

As shown in fig. 2, the present embodiment provides a W-type alumina-supported silicon carbide ceramic membrane, which includes an alumina support 1 having a W-type or saw-tooth surface geometry and a silicon carbide thin film 2 coated on the surface of the alumina support. The inner channel 5 of the alumina support body 1 is of a diamond structure. As shown in fig. 3, preferably, the alumina support 1 comprises a closed end 3 and a water passing end 4; wherein, the closed end 3 is integrally formed by alumina for sealing.

The extrusion die of this embodiment may have a transverse width of 270mm and an angle of the bottom and top of W of 60, as shown in FIG. 1.

(1) Adding 120g of zirconium carbonate into 6L of deionized water, heating and stirring, slowly adding 10g of citric acid at 90 ℃, keeping the temperature for 36 hours, stopping heating, maintaining stirring, and cooling to room temperature to obtain a sintering aid A for later use;

(2) Adding alumina (D50: 5-10 μm) with the purity of more than 99.5%, alumina (D50: 5-10 μm), lanthanum oxide, titanium oxide and yttrium oxide into a kneader according to the mass ratio of 25000g, 4100g, 10010045g, and then adding sintering aid A to mix for 1h to obtain an inorganic powder raw material;

(3) Mixing corn starch, PVA, glycerol and tung oil according to a mass ratio of 2000g;

(4) Mixing the inorganic powder raw material in the step (2) and the organic additive in the step (3) for 15 minutes, transferring the kneaded pug into a constant-temperature constant-humidity closed space with the temperature of 25 ℃ and the humidity of 90% for aging for 24-36 hours, transferring the aged pug into a vacuum pugging machine, mixing for 5 times under a non-vacuum condition, pugging for 5 times under the vacuum degree of 0.10MPa, then putting into an extruder, extruding through a die with an inner channel in a diamond structure, putting an extruded blank on a W-shaped aluminum plate, inclining for 20 degrees, and naturally airing for 12 hours;

(5) Putting the blank body into an oven for drying, wherein the temperature of the oven is 180 ℃, and the drying time is 26 hours; after drying, placing the qualified blank into a tunnel kiln or a shuttle kiln for sintering by detection, wherein the heating rate is 3 ℃/min, the sintering temperature is 1500 ℃, preserving the heat for 2 hours, controlling the cooling rate to be 3 ℃/min, and detecting after the temperature is reduced to the room temperature to obtain the alumina support body 1 with the surface geometry of W type or sawtooth shape;

(6) 100g of TiO₂Mixing the powder (D50: 25nm-50 nm) in 3000g sodium hydroxide solution with concentration of 10mol/L, ultrasonic dispersing for 10min-30min, transferring into a constant temperature oven at 200 deg.C or below, and standing for 48h. The resulting white precipitate was washed 5-8 times with 0.1mol/L dilute hydrochloric acid solution and then washed with deionized water to neutrality with the aid of ultrasonic waves. Roasting to 700 ℃ at the heating rate of 3 ℃/min in an electric furnace with program intelligent control, preserving heat for 2h, and controlling the cooling rate to be 3 ℃/min to room temperature to obtain the sintering aid B.

(7) 10g of 1N nitric acid is put into 1000g of deionized water, stirred at a low speed for 5 minutes, then 95g of silicon carbide (D50: 0.4-1 μm) powder and 5g of sintering aid B are slowly added, stirred at a high speed for 30 minutes, then 10g of PVA powder is slowly added, and stirring is continued for 30 minutes. Placing the mixture into a vacuum device with the vacuum degree of 0.01MPa, and stirring the mixture at a low speed for more than 30 minutes to obtain coating liquid.

(8) Transferring into a coating device by a slurry dipping method, sealing the openings of the channels at two ends of the alumina support body to be coated by using a sealing rubber strip to prevent coating liquid from entering the inner surfaces of the channels, and then placing into the coating device for dipping for 30s. Drying in an oven at 200 deg.C or below for 12h, sintering in a tunnel kiln or shuttle kiln at 1100 deg.C for 2 hr at 3 deg.C/min, cooling to 300 deg.C, and taking out of the kiln for detection to obtain the final product.

The ceramic membrane has the porosity of 30-50 percent and the average aperture of 100nm, greatly improves the hydrophilicity of the ceramic membrane, and has the pure water flux of 2-3m³·m^-2·h^-1·bar^-1The breaking strength is more than 35MPa, and the compressive strength is more than 80MPa.

Claims

1.W type alumina supports carborundum ceramic membrane, its characterized in that: the silicon carbide ceramic material comprises an alumina support (1) with a W-shaped or sawtooth-shaped surface geometry and a silicon carbide film (2) coated on the surface of the alumina support.

2. A ceramic membrane according to claim 1, wherein: the inner channel (5) of the alumina support body (1) is of a diamond structure.

3. A ceramic membrane according to claim 2, wherein: the transverse width of the diamond-shaped structure is less than 500mm, and the angle between the bottom and the top is 45-90 degrees.

4. A ceramic membrane according to claim 1, wherein: the alumina support body (1) comprises a closed end (3) and a water passing end (4); wherein, the closed end (3) is integrally formed by alumina for sealing.