阅读说明：本技术 一种碳纤维预制体高压浸渍加压碳化工艺及设备 (High-pressure impregnation pressurization carbonization process and equipment for carbon fiber preform ) 是由 王金铎 杨海春 邵河 李童 郭宾 陶国新 啜艳明 于 2020-06-16 设计创作，主要内容包括：本发明涉及一种碳纤维预制体高压浸渍加压碳化工艺及设备,设备包括外胆和内胆,内胆和外胆之间形成腔体,碳纤维预制体放入腔体内,通过压力和温控控制腔体内的压力和温度,完成一体化高压浸渍和加压碳化,工艺包括预制体编织、浸渍液制备、加入浸渍液、高压浸渍、加压碳化和产品出炉,本发明所提供的方法不需要采用气相沉积增密,通过对浸渍液的优化,通过一步高压浸渍,二步加压碳化即可完成生产过程。产品周期小于45天,产品密度大于1.50g/cm<Sup>3</Sup>,所提供的设备一体设计,科学合理,极大的降低了能耗。(The invention relates to a high-pressure impregnation pressure carbonization process and equipment for a carbon fiber preform, wherein the equipment comprises an outer liner and an inner liner, a cavity is formed between the inner liner and the outer liner, the carbon fiber preform is placed in the cavity, the pressure and the temperature in the cavity are controlled by the pressure and the temperature, and the integrated high-pressure impregnation and pressure carbonization are completedThe production process can be completed. The product cycle is less than 45 days, and the product density is more than 1.50g/cm 3 The provided equipment is designed integrally, is scientific and reasonable, and greatly reduces energy consumption.)

1. The high-pressure impregnation pressurization carbonization equipment for the carbon fiber preforms is characterized by comprising an outer liner (1) and an inner liner (2) which are matched with each other, wherein the upper ends of the outer liner (1) and the inner liner (2) are provided with openings, and a sealing cavity (3) for placing the carbon fiber preforms (4) is formed between the outer liner (1) and the inner liner; a shell (5) is arranged on the outer side of the outer container (1), a heat insulation material (7) is arranged in the shell (5), and an electric heating pipe (8) is arranged between the outer side of the outer container (1) and the heat insulation material (7); an upper cover (6) is arranged at the upper end of the inner container (2), a heat insulation material (7) is arranged on the inner side of the upper cover (6), and an electric heating pipe (8) is arranged on the inner side of the inner container (2); the sealing cavity (3) is connected with a pressure regulating chamber (10) through a vent pipeline (9), and an automatic pressure relief control valve (11), an automatic pressure increasing control valve (12) and a pressure gauge (13) are arranged on the pressure regulating chamber (10); the sealed cavity (3) is connected with an impregnation liquid pool (15) through a liquid inlet pipeline (14), and a high-pressure pump (16) and an electric valve (17) are arranged on the liquid inlet pipeline (14).

2. The carbon fiber preform high-pressure impregnation pressure carbonization apparatus as claimed in claim 1, wherein a temperature sensor is provided between the outer side of the outer liner (1) and the heat insulating material (7) and inside the inner liner (2).

3. The carbon fiber preform high-pressure impregnation and pressure carbonization apparatus as claimed in claim 1, wherein the outer shell (1) and the upper cover (6) are both provided with temperature control instruments (18), and the temperature control instruments (18) are respectively electrically connected with temperature sensors arranged between the outer side of the outer container (1) and the heat insulation material (7) and the inner side of the inner container (1).

4. The carbon fiber preform high-pressure impregnation pressure carbonization device as claimed in claim 1, wherein the upper ends of the outer liner (1) and the inner liner (2) are provided with annular outer edges, the outer edges of the outer liner (1) and the inner liner (2) are provided with corresponding threaded holes, and the outer liner (1) and the inner liner (2) are connected together through connecting bolts (19).

5. The carbon fiber preform high-pressure impregnation pressure carbonization apparatus according to claim 1, characterized in that a sealing ring (20) is provided between the outer edge of the outer container (1) and the outer edge of the inner container (2).

6. The carbon fiber preform high-pressure impregnation and pressure carbonization apparatus according to claim 1, wherein the top of the sealed chamber (3) is provided with a vent (2-1) connected to the vent line (9), and the bottom of the sealed chamber (3) is provided with an impregnation liquid inlet (1-1) connected to the liquid inlet line (14).

7. A carbon fiber preform high-pressure impregnation pressure carbonization apparatus according to claim 1, characterized in that the clearance at any of the seal cavities (3) is 2-3mm larger than the thickness of the carbon fiber preform (4) at that point.

8. A process for high-pressure impregnation pressure carbonization of carbon fiber preforms using the apparatus according to any one of claims 1 to 7, characterized in that it comprises the steps of:

(1) weaving the prefabricated body: adopting T700 protofilament to produce carbon cloth and net tyre, calculating dosage according to size density, cross-layer knitting, 30 needles/cm²Obtaining a carbon fiber preform;

(2) preparing an impregnation liquid: adding 0.5-1.0 wt% of one-dimensional or two-dimensional nano carbon material into coal tar pitch, and heating and mixing uniformly for later use;

(3) high-pressure impregnation: the impregnation liquid prepared in the step (2) has the density of the carbon fiber preform from 0.45g/cm according to the step (1)³Increase to 1.5g/cm³Adding the calculated amount of the carbon fiber preform, immersing the carbon fiber preform, and keeping the temperature of 140-160 ℃ for 1-2 hours under the condition of 5-8 MPa;

(4) pressure carbonization: after the treatment in the step (3) is completed, reducing the pressure to 2-4 MPa, and carrying out temperature programming to 850 +/-10 ℃ for carbonization for 3-4 h, wherein the temperature programming curve is as follows: heating to 230 ℃ for 3 h; 230 ℃ for 2 h; 230 to 650 ℃ for 18 h; 650 to 850 ℃ for 9 h; 850 ℃ for 4 h;

(5) discharging the product out of the furnace: cooling to room temperature, reducing the pressure to atmospheric pressure, and taking out the carbon fiber preform to obtain the carbon fiber preform.

9. The high-pressure impregnation pressure carbonization process of the carbon fiber preform as claimed in claim 8, wherein the softening point of the coal tar pitch in the step (2) is 90-100 ℃ and the coking value is more than 45%.

10. The high-pressure impregnation pressure carbonization process of the carbon fiber preform as claimed in claim 8, wherein the heating temperature in the step (2) is 150-180 ℃, and ultrasonic uniform mixing and stirring are adopted.

Technical Field

The invention relates to the field of carbon material preparation, in particular to a high-pressure impregnation pressurization carbonization process and equipment for a carbon fiber preform.

Background

The carbon/carbon crucible is a necessary consumable material for pulling monocrystalline silicon in the photovoltaic industry, and the method for manufacturing the carbon/carbon crucible at present in China is to densify the carbon fiber preform by vapor deposition to the density of 1.0g/cm³Then soaking in soaking equipment, transferring to other equipment for carbonization and densification, repeatedly soaking and carbonizing for 4-5 times to make product density reach 1.5g/cm³Above, the whole production cycle needs 90 days, the production procedures are more and less efficient, the energy loss is more, and the automation degree is lower.

In order to solve the problems, CN104446588A in the prior art discloses a liquid-phase impregnation densification method for a carbon fiber preform, which comprises an impregnation step, a low-temperature treatment step and a high-temperature carbonization step, wherein the carbon fiber preform is used as a reinforcement, high-temperature modified asphalt is used as a matrix impregnant, a pressurized impregnation device is used for carrying out liquid-phase impregnation densification treatment on a C/C material, and the density of the C/C material reaches 1.5 g-cm by adopting the conventional liquid-phase impregnation method^-3The above requires 8 to 10 cycles of densification.

Although the above technical solutions shorten the number of cycles, they cannot solve the problem that a single cycle is long and a complex process of switching devices is required, so that a new process method needs to be invented to meet the requirements of shortening the production cycle and improving efficiency without affecting the product quality.

Disclosure of Invention

The invention aims to solve the problems in the prior art, provides a high-pressure impregnation and pressurization carbonization process for a carbon fiber preform, and also provides equipment for implementing the process.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a high-pressure impregnation pressurization carbonization device for a carbon fiber preform, which comprises an outer liner and an inner liner which are matched with each other, wherein the upper ends of the outer liner and the inner liner are provided with openings, and a sealing cavity for placing the carbon fiber preform is formed between the outer liner and the inner liner; a shell is arranged on the outer side of the outer container, a heat insulation material is arranged in the shell, and an electric heating pipe is arranged between the outer side of the outer container and the heat insulation material; the upper end of the inner container is provided with an upper cover, the inner side of the upper cover is provided with a heat insulation material, and the inner side of the inner container is provided with an electric heating pipe; the sealing cavity is connected with a pressure regulating chamber through a vent pipeline, and the pressure regulating chamber is provided with an automatic pressure relief control valve, an automatic pressure increasing control valve and a pressure gauge; the sealed cavity is connected with the steeping liquor pool through a liquor inlet pipeline, and a high-pressure pump and an electric valve are arranged on the liquor inlet pipeline.

As a further improvement of the invention, temperature sensors are arranged between the outer side of the outer liner and the heat insulation material and on the inner side of the inner liner.

As a further improvement of the invention, the shell and the upper cover are both provided with temperature control instruments which are respectively and electrically connected with temperature sensors arranged between the outer side of the outer liner and the heat insulation material and the inner side of the inner liner.

As a further improvement of the invention, the upper ends of the outer liner and the inner liner are both provided with annular outer edges, the outer edges of the outer liner and the inner liner are provided with corresponding threaded holes, and the outer liner and the inner liner are connected together through connecting bolts.

As a further improvement of the invention, a sealing ring is arranged between the outer edge of the outer liner and the outer edge of the inner liner.

As a further improvement of the invention, the sealing ring is made of high-temperature-resistant aluminum silicate fiber felt.

As a further improvement of the invention, the top of the sealed cavity is provided with a vent connected with the vent pipeline, and the bottom of the sealed cavity is provided with an immersion liquid inlet connected with the liquid inlet pipeline.

As a further improvement of the invention, the clearance at any place of the sealed cavity is 2-3mm larger than the thickness of the carbon fiber preform.

As a further improvement of the invention, the heat-insulating material adopts rock wool.

The invention also provides a process for carrying out high-pressure impregnation pressure carbonization on the carbon fiber preform by using the equipment, which comprises the following steps:

(1) weaving the prefabricated body: adopting T700 protofilament to produce carbon cloth and net tyre, calculating dosage according to size density, cross-layer knitting, 30 needles/cm²Obtaining a carbon fiber preform;

(2) preparing an impregnation liquid: adding 0.5-1.0 wt% of one-dimensional or two-dimensional nano carbon material into coal tar pitch, and heating and mixing uniformly for later use;

(3) high-pressure impregnation: the impregnation liquid prepared in the step (2) has the density of the carbon fiber preform from 0.45g/cm according to the step (1)³Increase to 1.5g/cm³Adding the calculated amount of the carbon fiber preform, immersing the carbon fiber preform, and keeping the temperature of 140-160 ℃ for 1-2 hours under the condition of 5-8 MPa;

(4) pressure carbonization: after the treatment in the step (3) is completed, reducing the pressure to 2-4 MPa, and carrying out temperature programming to 850 +/-10 ℃ for carbonization for 3-4 h, wherein the temperature programming curve is as follows: heating to 230 ℃ for 3 h; 230 ℃ for 2 h; 230 to 650 ℃ for 18 h; 650 to 850 ℃ for 9 h; 850 ℃ for 4 h;

(5) discharging the product out of the furnace: cooling to room temperature, reducing the pressure to atmospheric pressure, and taking out the carbon fiber preform to obtain the carbon fiber preform.

As some embodiments of the invention, the coal tar pitch in the step (2) has a softening point of 90-100 ℃ and a coking value of more than 45%.

As some embodiments of the invention, the mixing temperature in the step (2) is 150-180 ℃, and ultrasonic mixing and stirring are adopted.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

the method provided by the invention does not need to adopt vapor deposition for densification, and can complete the production process by optimizing the impregnation liquid, carrying out one-step high-pressure impregnation and carrying out two-step pressure carbonization. The product cycle is less than 10 daysThe product density is more than 1.5g/cm³。

According to the carbon fiber preform high-pressure impregnation pressurization carbonization all-in-one machine, vapor deposition densification is not needed, the high-pressure impregnation and pressurization carbonization processes can be completed on one device, automatic control and safe production are achieved through the pressure gauge and the temperature control instrument, rapid densification and carbonization are achieved, production procedures are reduced, energy consumption is reduced, production efficiency is improved, the internal structure of a product can be guaranteed to be uniform, and the service life of the product is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural view of the present invention.

Wherein: the device comprises an outer container 1, a steeping liquid inlet 1-1, an inner container 2, an air vent 2-1, a sealing cavity 3, a carbon fiber preform 4, a shell 5, an upper cover 6, a heat insulation material 7, an electric heating pipe 8, an air vent pipeline 9, a pressure adjusting chamber 10, an automatic pressure relief control valve 11, an automatic pressure increasing control valve 12, a pressure gauge 13, a liquid inlet pipeline 14, a steeping liquid pool 15, a high-pressure pump 16, an electric valve 17, a temperature control instrument 18, a connecting bolt 19, a sealing ring 20 and a power supply lead 21.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail and fully with reference to the following embodiments.