CN114440236A - A method and equipment for the resource utilization of exhaust gas in the densification process of carbon-carbon composite materials - Google Patents

Abstract

The invention discloses a carbon/carbon composite material densification process tail gas resource utilization method and equipment, which belong to the technical field of material processing tail gas separation and utilization. The condensing gas-liquid separator separates the gas from the liquid and solid, and the separation step is very simple and efficient; the gas is pumped from the condenser to the gas cabinet by the Roots fan for storage. When the product needs to be deposited, the vacuum pump of the deposition furnace will The gas is pumped into the deposition furnace and used as the raw material for the vapor deposition of carbon in the deposition furnace to realize a part of resource utilization; the exhaust gas generated in the further deposition process passes through the exhaust gas treatment system, and the carbonized solid-liquid products can be discharged into the burner. Combustion is carried out in the combustion chamber, and the heat energy of the combustion can be introduced into the impregnation furnace for heating, realizing a higher utilization rate of resources.

Description

A method and equipment for the resource utilization of exhaust gas in the densification process of carbon-carbon composite materials

technical field

The invention relates to the technical field of material processing tail gas separation and utilization, in particular to a method and equipment for the resource utilization of tail gas in the densification process of carbon/carbon composite materials.

Background technique

Carbon/carbon composite material (c-c composite or carbon-carbon composite material) is a carbon matrix composite material reinforced by carbon fiber and its fabric. It has excellent friction and wear performance, and has the advantages of light weight, low noise, shock absorption, braking and safety. It is considered to be one of the most promising high-temperature materials and has been widely used in aerospace, automobile Industry, medicine and other fields, such as rocket engine nozzles and their throat linings, space shuttle end caps and thermal protection systems for the leading edge of wings, aircraft brake discs, etc.

Generally, in the process of preparing carbon/carbon composite materials by the CVI method, the carbon source gas containing a large amount of tar, carbon black, coke particles, carbon fibers, condensable macromolecules and other heterogeneous impurities and incompletely reacted carbon source gas needs to pass through the vacuum pumping system of the CVI furnace. Out of the furnace, these impurities enter the vacuum extraction system of the CVI furnace, which will seriously pollute, block the pipeline, damage the valves, inspection and control equipment, vacuum pumps, etc., which will seriously affect the continuous and reliable operation of the CVI furnace.

At present, in the carbon/carbon composite material processing technology we use, because the carbon fiber preform (carbon fiber preform is the skeleton of carbon/carbon composite material), the product enters the vacuum pressure impregnation tank after CVI for impregnation, and the impregnation adopts modified asphalt, pitch After the impregnation, it will enter the carbonization process, and the pitch will produce solid carbon, non-condensable gas, oil and other products under the carbonization condition. Because the previous process adopts a cyclic treatment method in this step (as shown in Figure 1 of the description, The carbonization and impregnation process part of the cycle treatment), but no more refined separation of the products in the production process, the resource utilization rate is not high. Therefore, how to deal with various products more efficiently and effectively improve the efficiency of resource recycling is a problem that needs to be further solved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to address the above problems, provide a carbon/carbon composite material densification process tail gas resource utilization method and equipment, after the solid-liquid product generated in the high-pressure impregnation process of the modified asphalt is separated, the tail gas is passed through the heat dissipation. At the same time, the heat of combustion is introduced into the impregnation furnace for utilization; the burner is designed in a targeted multi-stage type, which can burn the exhaust gas more fully, reduce the emission of harmful substances, and can burn all levels of combustion. The heat of the chamber is efficiently introduced into the heat pipe to improve the utilization rate of heat energy.

In order to achieve the above purpose, the technical solution adopted in the present invention is: a carbon/carbon composite material densification process tail gas resource utilization method, comprising the following steps:

A. The carbon-carbon composite product passes through CVI and then enters the impregnation furnace for impregnation;

B. Modified asphalt is used for impregnation. In the high-pressure impregnation process, asphalt is the product of further thermal processing of coal tar or by-products of petroleum processing. The mixture of countless organic substances, the impregnated asphalt then enters the carbonization process, and the asphalt will produce solid carbon, non-condensable gas, oil and other products under carbonization conditions;

C. The carbonized tail gas is condensed to separate the gas from the liquid and solid. The solid-liquid mixture composed of liquid and solid is deposited in the lower part of the condenser, which can be taken out later and put into the burner for combustion;

D. The gas is pumped from the condenser to the gas cabinet through the Roots fan for preservation;

E. When deposition is required, the gas is pumped into the deposition furnace through the vacuum pump of the deposition furnace, as the raw material of the vapor deposition carbon of the deposition furnace;

F. The exhaust gas generated in the deposition process is discharged into the combustion chamber of the burner for combustion after the exhaust gas treatment system;

G. The burner burns the carbonized solid/liquid mixture and the tail gas discharged from the deposition furnace, and the heat of combustion is sent to the impregnation furnace for heating through the heat transfer pipe connected to the burner.

Further, the temperature of the impregnation condition in the step B is 200-350 ℃, the pressure is 3-10MPa, and the solid carbon content in the product of the asphalt under the impregnation condition is 9.3%-11.3%, and the non-condensable gas is 9.3%-11.3%. The content of aromatic hydrocarbons below C8 is 68.6%-71.6%, the content of phenol in non-condensable gas is 1.8%-2.4%, and the content of oil is 16-18%.

In addition, the present invention also discloses a device for resource utilization of exhaust gas in the densification process of carbon/carbon composite materials, including a burner, the burner is supported and fixed by a bracket, the burner is communicated with an oxygen delivery pipe, and the burner is The upper and lower two-stage combustion chambers are separated by partitions, the lower layer is the first-level combustion chamber, and the upper layer is the second-level combustion chamber. A movable baffle is symmetrically arranged on both sides of the inlet, and a scraper is connected to one side of the baffle; a through hole is opened on the baffle and a movable sealing plate is arranged at the through hole, and the exhaust gas inlet is connected with the through hole of the baffle. An igniter is arranged beside it; the outer walls of the primary combustion chamber and the secondary combustion chamber are both connected with a heat conduction pipe.

Further, the bottom of the bottom plate of the first-stage combustion chamber is a horizontal straight plate, and the two sides of the horizontal straight plate are symmetrical inclined plate structures, and the bottom of the baffle is hinged with the inclined plate; A rotating shaft is installed on the symmetrical mounting plate, and the bottom end of the baffle is connected with the rotating shaft.

Further, one side of the baffle is hinged with a connecting rod, the other end of the connecting rod is connected with a scraper, and the side wall of the connecting rod is connected with the strut on the inner wall of the primary combustion chamber through a bearing.

Further, the connecting rod is connected with the scraper through a second spring; the scraper is in contact with the inner wall of the primary combustion chamber provided with the observation window.

Further, the upper wall of the partition is a concave structure located at the through hole, the bottom surface of the sealing plate is a convex structure matched with the concave surface at the through hole; the bottom surface of the sealing plate is connected to the elastic limiting component.

Further, the elastic limiting assembly includes a first spring connected to the bottom surface of the sealing plate, the bottom end of the first spring is connected to the mounting frame, the side plate of the mounting frame is connected to the bottom surface of the partition plate, and the first spring is connected to the mounting frame. The bottom plate of the rack is connected.

Further, a heat conduction plate is arranged on the side wall of the primary combustion chamber, and the outer side of the heat conduction plate is covered by a heat conduction channel; a hot gas outlet is opened on the side wall of the secondary combustion chamber, and the hot gas outlet is communicated with the heat conduction channel, and the upper end of the heat conduction channel is opened. communicate with the heat pipe.

Further, the heat conduction channel is composed of a heat insulation frame, the side walls of the primary combustion chamber and the secondary combustion chamber; the heat conduction plate is arranged through the primary combustion chamber; and the hot gas outlet is an oblique opening structure.

Beneficial effects of the present invention:

The method of the invention can efficiently separate and collect the tail gas produced by the impregnation in the process, and then use the burner for combustion treatment, and at the same time reuse the heat generated by the combustion, so as to improve the recycling utilization rate of resources. Since the impregnation process adopts modified asphalt, the asphalt is the product of further thermal processing of coal tar or by-products of petroleum processing. The mixture and asphalt produce various products of solid, liquid and gas at the same time under the impregnation condition. The gas is separated from the liquid and solid by the condensing gas-liquid separator. The separation step is very simple and efficient; the gas is pumped from the condenser through the Roots fan. It is stored in the cabinet. When deposition is required, the gas is pumped into the deposition furnace by the vacuum pump of the deposition furnace, as the raw material of the vapor deposition carbon of the deposition furnace, to realize part of the resource utilization; the exhaust gas generated in the further deposition process passes through the exhaust gas. After the treatment system, it is discharged into the combustion chamber of the burner for combustion, and the heat energy of the combustion can be introduced into the impregnation furnace for heating.

In the burner of the present invention, in order to solve the problem of insufficient gas combustion, the combustion chamber inside the burner is divided into a lower primary combustion chamber and an upper secondary combustion chamber by a partition plate, and through holes are arranged on the partition plate to pass through the combustion chamber. The hole is sealed by a movable sealing plate. Because there are symmetrical baffles inside the primary combustion chamber, a small combustion space is formed, and the bottom of the baffle is hinged; when the exhaust gas enters the primary combustion chamber from the bottom and is ignited, the instantaneous expansion will push the baffle toward the Push open on both sides, and the baffle rotates around the shaft at the bottom; since one side of the baffle is connected with a scraper through a connecting rod and a second spring, and the middle of the connecting rod is connected to the strut through a bearing, the connecting rod can rotate around the strut , when the baffle moves, it can drive the connecting rod to rotate, and then push the scraper through the second spring to scrape off the residue on the inner wall of the primary combustion chamber and the observation window, which not only reduces the residue, but also prevents the observation window from being backlogged. The masking of residues makes it impossible to observe the combustion inside the combustion chamber.

When the internal temperature of the primary combustion chamber rises sharply and the pressure increases, the sealing plate above the through hole of the partition plate can be punched open, so that the gas continues to enter the upper secondary combustion chamber and contact with a larger area of oxygen. It can promote more complete combustion of exhaust gas. At the same time, the inner wall of the first-stage combustion chamber is provided with a heat-conducting plate, which can guide heat into the heat-conducting channel; and the hot gas in the second-stage combustion chamber can directly enter the heat-conducting channel and heat-conducting pipe for recycling, which improves the resources of various products in the processing process. utilization rate.

Of course, it is not necessary for any product embodying the present invention to achieve all of the above-described advantages simultaneously.

Description of drawings

Fig. 1 is a schematic flow diagram of a traditional process method.

Fig. 2 is the process flow schematic diagram of the present invention

Fig. 3 is an overall schematic view of the burner of the present invention.

FIG. 4 is a schematic diagram of the internal structure of the burner of the present invention.

FIG. 5 is a schematic diagram of the installation structure of the scraper of the present invention.

FIG. 6 is a schematic diagram of the installation of the sealing plate of the present invention.

FIG. 7 is a schematic diagram of the installation of the connecting rod of the present invention.

The characters in the figure are marked as follows: 1. Bracket; 2. Combustion chamber; 3. Exhaust gas inlet; 4. Heat conduction pipe; 5. Hot gas outlet; 6. Partition plate; 1st spring; 10, mounting frame; 11, scraper; 12, baffle plate; 13, second spring; 14, connecting rod; 15, heat conduction plate; 16, rotating shaft; 17, installation plate; 18, heat conduction channel; 19 , pillar; 20, primary combustion chamber; 21, secondary combustion chamber.

Detailed ways

The present invention is further illustrated by the following examples.

A carbon/carbon composite material densification process tail gas resource utilization method, comprising the following steps:

A. The carbon-carbon composite product passes through CVI and then enters the impregnation furnace for impregnation;

B. Modified asphalt is used for impregnation. In the high-pressure impregnation process, asphalt is the product of further thermal processing of coal tar or by-products of petroleum processing. The mixture of countless organic substances, the impregnated asphalt then enters the carbonization process, and the asphalt will produce solid carbon, non-condensable gas, oil and other products under the condition of impregnation and carbonization;

C. The carbonized tail gas is condensed to separate the gas from the liquid and solid. The solid-liquid mixture composed of liquid and solid is deposited in the lower part of the condenser, which can be taken out later and put into the burner for combustion;

D. The gas is pumped from the condenser to the gas cabinet through the Roots fan for preservation;

E. When deposition is required, the gas is pumped into the deposition furnace through the vacuum pump of the deposition furnace, as the raw material of the vapor deposition carbon of the deposition furnace;

F. After the exhaust gas generated in the deposition process passes through the exhaust gas treatment system, it is discharged into the combustion chamber 2 of the burner for combustion;

G. The burner burns the carbonized solid/liquid mixture and the tail gas discharged from the deposition furnace, and the heat of combustion is sent to the impregnation furnace for heating through the heat transfer pipe 4 connected to the burner.

Preferably, the temperature of the impregnation condition in the step B is 200-350°C, the pressure is 3-10MPa, and the solid carbon content in the product of the asphalt under the impregnation condition is 9.3%-11.3%, and the non-condensable gas is 9.3%-11.3%. The content of aromatic hydrocarbons below C8 is 68.6%-71.6%, the content of phenol in non-condensable gas is 1.8%-2.4%, and the content of oil is 16-18%.

In addition, the present invention also discloses a carbon/carbon composite material densification process exhaust gas utilization equipment, including a burner, the burner is supported and fixed by a bracket 1, the burner is communicated with an oxygen delivery pipe, and the inside of the burner passes through a partition plate 6 is separated into upper and lower two-stage combustion chambers, the lower layer is a primary combustion chamber 20, the upper layer is a secondary combustion chamber 21, and the bottom plate of the primary combustion chamber 20 is provided with a tail gas inlet 3 to communicate with the exhaust gas discharge pipeline, and the primary combustion chamber 20 The bottom plate is located on both sides of the exhaust gas inlet 3 symmetrically with movable baffles 12, and one side of the baffle 12 is connected with a scraper 11; the baffle 6 is provided with a through hole and the through hole is provided with a movable sealing plate 7, An igniter 8 is arranged beside the exhaust gas inlet 3 and the through hole of the partition plate 6 ;

Preferably, as shown in Figures 3, 5 and 6, the upper wall of the partition plate 6 at the through hole is a concave structure, and the bottom surface of the sealing plate 7 is a convex structure matching the concave surface at the through hole; the The bottom surface of the sealing plate 7 is connected with the elastic limiting component. The elastic limit assembly includes a first spring 9 connected to the bottom surface of the sealing plate 7, the bottom end of the first spring 9 is connected to the mounting frame 10, the side plate of the mounting frame 10 is connected to the bottom surface of the partition plate 6, the first The spring 9 is connected to the bottom plate of the mounting frame 10 . The bottom surface structure of the sealing plate 7 can effectively disperse the impact force, buffer the airflow, and can also cooperate with the igniters 8 on both sides of the sealing plate 7 to introduce the airflow into the burner 8 to ensure the ignition effect.

Preferably, as shown in FIGS. 3 , 4 and 5 , a heat-conducting plate 15 is provided on the side wall of the primary combustion chamber 20 , and the outer side of the heat-conducting plate 15 is covered by a heat-conducting channel 18 ; the side wall of the secondary combustion chamber 21 is A hot gas outlet 5 is opened on the top, and the hot gas outlet 5 is communicated with the heat conduction channel 18 , and the upper end of the heat conduction channel 18 is communicated with the heat conduction pipe 4 . The heat conduction channel 18 is composed of a heat insulation frame, the side walls of the primary combustion chamber 20 and the secondary combustion chamber 21 ; the heat conduction plate 15 is arranged through the primary combustion chamber 20 ; the hot gas outlet 5 is an oblique opening structure.

Preferably, as shown in FIGS. 3 , 4 and 5 , the bottom of the bottom plate of the primary combustion chamber 20 is a horizontal straight plate and two sides of the horizontal straight plate are symmetrical inclined plate structures, and the bottom of the baffle 12 is hinged to the inclined plate ; On the inclined plate of the bottom plate of the first-stage combustion chamber 20, a rotating shaft 16 is installed through a symmetrical mounting plate 17, and the bottom end of the baffle plate 12 is connected with the rotating shaft 16. One side of the baffle plate 12 is hinged with a connecting rod 14 , the other end of the connecting rod 14 is connected with a scraper 11 , and the side wall of the connecting rod 14 is connected to the strut 19 on the inner wall of the primary combustion chamber 20 through a bearing. The connecting rod 14 is connected with the scraper 11 through the second spring 13; the scraper 11 is in contact with the inner wall of the primary combustion chamber 20 provided with the observation window. The scraper 11 can scrape off the accumulated residues on the inner wall and the observation window at the same time, and cooperate with the bottom plate of the sloping plate structure of the primary combustion chamber 20 to facilitate cleaning from the exhaust gas inlet 3. The second spring 13 can not only keep the scraper 11 in contact with the inner wall at all times, but when the connecting rod 14 rotates, the compressed second spring 13 is reduced in force and extended, and can also push the scraper 11 to scrape down residues .

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus.

The principles and embodiments of the present invention are described herein, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; meanwhile, for those skilled in the art, according to the idea of the present invention, There will be changes in the implementation manner and the application scope. To sum up, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A tail gas resource utilization method in a carbon/carbon composite material densification process is characterized by comprising the following steps:

A. the carbon/carbon composite material product is subjected to CVI and then enters an impregnation furnace for impregnation;

B. the impregnation adopts modified asphalt, in the high-pressure impregnation process, the asphalt is a product formed by further hot processing coal tar or petroleum processing byproducts, a mixture of numerous organic matters with a main body of polynuclear condensed aromatic hydrocarbon and extremely wide molecular weight distribution and different melting points is subjected to a carbonization process, and the asphalt can generate solid carbon, non-condensable gas, oil and other products under the carbonization working condition;

C. the carbonized tail gas is condensed, gas, liquid and solid are separated, the liquid and the solid form a solid-liquid mixture and precipitate at the lower part of the condenser, and the solid-liquid mixture can be taken out at the later stage and put into a combustor for combustion;

D. pumping the gas from the condenser to a gas holder by a Roots blower for storage;

E. when deposition is needed, pumping gas into the deposition furnace through a vacuum pump of the deposition furnace to be used as a raw material of vapor deposition carbon of the deposition furnace;

F. tail gas generated in the deposition process is discharged into a combustion chamber (2) of the combustor for combustion after passing through a tail gas treatment system;

G. the burner burns the solid/liquid mixture obtained by burning the carbon and the tail gas discharged by the deposition furnace, and the heat of combustion is transferred to the impregnation furnace for heating through a heat pipe (4) connected with the burner.

2. The resource utilization method of tail gas in the densification process of the carbon/carbon composite material as claimed in claim 1, wherein the temperature of the impregnation working condition in the step B is 200-350 ℃, the pressure is 3-10MPa, and the product of the asphalt under the impregnation working condition has the solid carbon content of 9.3% -11.3%, the content of aromatic hydrocarbons below C8 in the non-condensable gas of 68.6% -71.6%, the content of phenols in the non-condensable gas of 1.8% -2.4% and the content of oil of 16-18%.

3. The equipment for recycling tail gas in the densification process of the carbon/carbon composite material, which is disclosed by any one of claims 1-2, comprises a combustor, wherein the combustor is supported and fixed through a support (1) and is communicated with an oxygen conveying pipe, and is characterized in that the combustor is internally divided by a partition plate (6) to form an upper combustion chamber and a lower combustion chamber, the lower combustion chamber is a primary combustion chamber (20), the upper combustion chamber is a secondary combustion chamber (21), a tail gas inlet (3) is formed in the bottom plate of the primary combustion chamber (20) and is communicated with a tail gas discharge pipeline, movable baffles (12) are symmetrically arranged on two sides, located on the tail gas inlet (3), of the bottom plate of the primary combustion chamber (20), and one side of each baffle (12) is connected with a scraper (11); a through hole is formed in the partition plate (6), a movable sealing plate (7) is arranged at the through hole, and igniters (8) are arranged beside the tail gas inlet (3) and the through hole of the partition plate (6); the outer walls of the primary combustion chamber (20) and the secondary combustion chamber (21) are connected with the heat conducting pipe (4).

4. The equipment for recycling the tail gas in the carbon/carbon composite material densification process as recited in claim 3, wherein the bottom of the bottom plate of the primary combustion chamber (20) is a horizontal straight plate, and two sides of the horizontal straight plate are symmetrical inclined plate structures, and the bottom of the baffle (12) is hinged with the inclined plate; the rotary shaft (16) is installed on the inclined plate of the bottom plate of the primary combustion chamber (20) through a symmetrical installation plate (17), and the bottom end of the baffle plate (12) is connected with the rotary shaft (16).

5. The equipment for recycling the tail gas in the densification process of the carbon/carbon composite material as claimed in claim 4, wherein one side of the baffle (12) is hinged with a connecting rod (14), the other end of the connecting rod (14) is connected with a scraper (11), and the side wall of the connecting rod (14) is connected with a pillar (19) on the inner wall of the primary combustion chamber (20) through a bearing.

6. The carbon/carbon composite material densification process tail gas resource utilization device according to claim 5, characterized in that the connecting rod (14) is connected with the scraper (11) through a second spring (13); the scraper (11) is contacted with the inner wall of the first-stage combustion chamber (20) provided with an observation window.

7. The equipment for recycling the tail gas in the carbon/carbon composite material densification process as claimed in claim 3, wherein the upper wall of the partition plate (6) at the through hole is of a concave structure, and the bottom surface of the sealing plate (7) is of a convex structure matched with the concave surface at the through hole; the bottom surface of the sealing plate (7) is connected with the elastic limiting component.

8. The carbon/carbon composite material densification process tail gas resource utilization device according to claim 7, wherein the elastic limiting assembly comprises a first spring (9) connected with the bottom surface of the sealing plate (7), the bottom end of the first spring (9) is connected with a mounting frame (10), the side plate of the mounting frame (10) is connected with the bottom surface of the partition plate (6), and the first spring (9) is connected with the bottom plate of the mounting frame (10).

9. The carbon/carbon composite material densification process tail gas resource utilization equipment according to claim 3, characterized in that a heat conducting plate (15) is arranged on the side wall of the primary combustion chamber (20), and the outer side of the heat conducting plate (15) is covered by a heat conducting channel (18); the side wall of the secondary combustion chamber (21) is provided with a hot gas outlet (5), the hot gas outlet (5) is communicated with a heat conduction channel (18), and the upper end of the heat conduction channel (18) is communicated with the heat conduction pipe (4).

10. The carbon/carbon composite material densification process tail gas resource utilization device according to claim 9, wherein the heat conduction channel (18) is composed of a heat insulation frame, a primary combustion chamber (20) and a secondary combustion chamber (21) side wall; the heat conducting plate (15) penetrates through the primary combustion chamber (20); the hot gas outlet (5) is of an inclined opening structure.

Images