TWI445661B - Continuous negative pressure carbonization apparatus and method of the same - Google Patents

Description

Continuous negative pressure carbonization device and carbonization method

The present invention relates to a continuous carbonization apparatus and a carbonization method, and more particularly to a continuous carbonization apparatus and a carbonization method for carbonization in a negative pressure environment.

Carbonization devices are used in a wide variety of applications, such as in the manufacture of carbon fiber fabrics. The existing continuous carbonization apparatus and method are applied to a carbonization chamber of a carbonization apparatus at a high temperature and are supplied with a large amount of an inert gas such as nitrogen (N2). Thereby, when a raw material (such as a fabric) is fed into the carbonization chamber for carbonization, the inert gas can exclude the raw material from coming into contact with oxygen in the air to make the non-carbon element contained in the raw material from the raw material body in a high-temperature process. Remove to leave carbon (ie, such as carbon fiber fabric).

Since a large amount of inert gas is introduced into the carbonization chamber, the carbonization chamber is in a positive pressure atmosphere (compared to the atmosphere outside the carbonization chamber), that is, the gas pressure in the carbonization chamber is greater than that outside the carbonization chamber. Atmospheric pressure.

However, in a positive pressure environment, non-carbon elements are less likely to be removed and gas removal will fill the cavity, resulting in an increase in ash content, tar production and a reduction in carbonation (because the non-carbon elements in the raw material are at positive pressure) It is not easy to remove from the raw material body under the atmosphere and affect the rearrangement of the carbon layer).

Therefore, there is a need for an improved continuous carbonization apparatus and carbonization method to solve the aforementioned problems.

Therefore, the object of the present invention is to provide a continuous carbonization apparatus and a carbonization method for carbonizing a raw material in a negative pressure carbonization chamber, wherein the pressure of the carbonization chamber is less than one atmosphere, and is a negative pressure state.

A continuous negative pressure carbonization apparatus according to the present invention comprises a supply device, a cavity device and a receiving device. The feeding device provides a raw material. The cavity device receives and carbonizes the raw material.

The cavity device comprises a carbonization device and two buffer devices. The carbonization device has a carbonization chamber having a feed port and a discharge port. The buffer devices are respectively connected to the feed port and the discharge port. The receiving device collects the carbonized raw material. When the raw material is carbonized in the carbonization chamber, the pressure of the carbonization chamber is a negative pressure state of less than one atmosphere.

A continuous negative pressure carbonization process in accordance with the present invention comprises providing a continuous raw material. Next, the carbonization chamber is used to carbonize the raw material. When the raw material is carbonized in the carbonization chamber, the pressure of the carbonization chamber is a negative pressure state of less than one atmosphere.

The effect that can be achieved according to the present invention is that the non-carbon gas generated in the carbonization chamber is easily removed when the raw material is carbonized in the carbonization chamber. The carbonized raw material (ie product) has a relatively uniform carbon layer and a high degree of carbonization.

At the same time, less ash is produced in the carbonization chamber (avoiding the removal of gases from the carbonized raw materials, such as carbon cloth). The carbonized raw material, such as carbon cloth, has a high degree of uniformity.

Finally, since there is no need to supply a large amount of nitrogen all the time, plus a buffer The design has been able to isolate the effects of oxygen in the external air in a continuous process, resulting in less energy consumption of inert gases (such as nitrogen) and less heat loss (a large amount of inert gas such as nitrogen entering the carbonization chamber will carry away heat).

The continuous carbonization apparatus and carbonization method according to the present invention is provided in a carbonization chamber of the carbonization apparatus to provide a negative pressure environment for carbonization in a negative pressure environment when the raw material enters the carbonization chamber. Applications of the present invention include, but are not limited to, carbon fiber fabrics for use in other carbonization processes for continuous supply and receipt of raw materials. For convenience of explanation, the following examples illustrate the carbonization of the fiber fabric as an example.

Referring to FIG. 1 , a carbonization apparatus 100 according to a first embodiment of the present invention includes a feeding device 110 , a cavity device 120 , a receiving device 130 , a gas supply device 140 , a heat exchanger 150 , and a pumping device . Gas device 160. The feeding device 110 may include a plurality of rollers 111 that supply the raw material 200 by the roller 111 and control the tension of the raw material 200. In the present embodiment, the raw material 200 is a fiber woven fabric.

After passing through the cavity device 120, the raw material 200 is carbonized into a carbon fiber woven fabric and collected by the receiving device 130.

The cavity device 120 includes a carbonization device 121 and a plurality of buffer devices 122. The buffering device 122 is respectively disposed at the feeding port and the discharging port position of the carbonizing device 121. In the present embodiment, the carbonization device 121 includes a carbonization chamber 123, and each of the buffer devices 122 includes a buffer cavity 124. The buffer cavity 124 of each buffer device 122 can also be configured as a plurality according to actual needs. One. The carbonization device 121 is further provided with a gas scrubbing port 125 connected to the carbonization chamber 123 to gas-carbonize the carbonization chamber 123.

The gas supply device 140 is connected to the buffer cavity 124 and the carbonization cavity 123, respectively, to provide a buffer cavity 124 and a carbonization chamber 123 inert gas such as nitrogen. The gas supply device 140 includes control valves (such as V1 and V2 in the figure) to control the flow rate of the gas entering the buffer chamber 124 in conjunction with the pressure meter (P1 and P2 in the figure) to keep the buffer chamber 124 in positive The pressure state (relative to the carbonization chamber 123); the gas supply device 140 further includes a control valve (V4 in the figure) to control the inert gas gas amount entering the carbonization chamber 123 in conjunction with the oxygen meter 126.

The air extracting device 160 is connected to the carbonization chamber 123 to extract the gas generated by the carbonized raw material, and the air extracting device 160 includes a control valve (V3 in the figure) to be controlled by the pressure meter (P3 in the figure). The gas flow rate of the carbonization chamber 123 is extracted to maintain the carbonization chamber 123 in a negative pressure state (relative to the buffer chamber 124).

The heat exchanger 150 is disposed between the cavity device 120 and the air supply device 140 and the air extraction device 160, so that the high temperature carbonized gas extracted by the air suction device 160 and the inert gas of the air supply device 140 exchange heat to heat the inertia. gas.

In the present embodiment, the pressure of the buffer chamber 124 is maintained to be greater than 760 Torr, that is, greater than one atmosphere (P2, P1 > 1 atm > P3). The pressure of the carbonization chamber 123 is maintained between 1-760 torr, i.e., less than one atmosphere. Before the raw material 200 enters the carbonization chamber 123, an inert gas such as nitrogen is introduced into the carbonization chamber 123 through the gas supply port 125 to reduce the cavity space. Gas and oxygen content.

During the process, the carbonization chamber 123 maintains a negative pressure. In addition, the carbonization chamber 123 may be provided with an oxygen meter 126 for setting the oxygen concentration in the carbonization chamber 123. When the oxygen concentration in the carbonization chamber 123 exceeds the set value, the inert gas may be again introduced through the gas supply port 125, such as Nitrogen enters the carbonization chamber 123 to reduce the oxygen content in the chamber to maintain the oxygen concentration between 1 ppm and 10%.

In addition, the heating time of the raw material 200 in the carbonization chamber 123 is from 1 minute to 25 minutes. The tension of the raw material 200 can be tensioned or tension-free to control the shrinkage of the raw material 200 and to avoid damage. The treatment temperature in the carbonization chamber 123 is between 500 ° C and 1200 ° C.

Referring to FIG. 2, a carbonization apparatus according to a second embodiment of the present invention is shown. The second embodiment is substantially the same as the first embodiment. The difference between the two is only that the air supply unit 140 is connected to The chamber 123 is carbonized to provide an inert gas of the carbonization chamber 123, such as nitrogen. The gas supply device 140 includes a control valve (V4 in the figure) to control the gas consumption of the inert gas entering the carbonization chamber gas scrubbing port 125 in conjunction with the oxygen meter 126.

The air suction device 160 is connected to the buffer cavity 124 and the carbonization cavity 123, respectively, to extract air therein. The air extracting device 160 includes control valves (such as V1, V2, and V3 in the figure) to control the gas flow rate of the pumping buffer chamber 124 and the carbonizing chamber 123, respectively, in conjunction with the pressure meter (P1, P2, and P3 in the figure). The buffer chamber 124 and the carbonization chamber 123 are maintained in a negative pressure state (relative to atmospheric pressure).

In this embodiment, the pressure of the carbonization cavity 123 is greater than the buffer cavity 124. The pressure is 1atm>P3>P1, P2. Therefore, the gas generated by the carbonization in the carbonization chamber 123 flows into the buffer chamber 124 and is discharged by the air suction device 160. The pressure of the carbonization chamber 123 is maintained between 1-760 torr, i.e., less than one atmosphere.

During the process, the carbonization chamber 123 maintains a negative pressure. In addition, the carbonization chamber 123 may be provided with an oxygen meter 126 for setting the oxygen concentration in the carbonization chamber 123. When the oxygen concentration in the carbonization chamber 123 exceeds the set value, the inert gas may be again introduced through the gas supply port 125, such as Nitrogen enters the carbonization chamber 123 to reduce the oxygen content in the chamber to maintain the oxygen concentration between 1 ppm and 10%.

If the same PAN (PolyAcryloNitrile) polyacrylonitrile oxidized fiber cloth is used as the raw material for carbonization, the process conditions (experimental group) of the first embodiment and the process conditions (control group) used in the prior art are respectively processed and carbonized. Get carbon fiber cloth. The process conditions are as follows: Process conditions of the control group: (for example, a 50-meter carbon cloth is produced) Temperature: 1000 ° C; heat treatment time: 10 minutes; tension: 3.0-4.0 kg; pressure inside the carbonization chamber 123: greater than ( >) 760 tor (N2 is introduced into the carbonization chamber 123 as a shielding gas); power consumption: 110-115 KW/hr; N ₂ (total) dosage: 188 kg.

Process conditions of the experimental group: (for the production of 50 meters of carbon cloth as an example) Temperature: 1000 ° C; heat treatment time: 10 minutes; Tension: 3.0-4.0 kg; pressure inside the carbonization chamber 123: less than (<) 760 tor (about 450-500 tor); power consumption: 95-100 KW / hr; N ₂ (total) dosage: 105 kg.

The carbon cloth obtained from the two groups can be tested to obtain the following results:

As can be seen from the above table, according to the negative pressure carbonization method of the present invention, the process power consumption is reduced by 13.4%, and the N ₂ consumption is reduced by 44.1%. If further analyzing the microstructure of the carbon fiber cloth produced by continuous negative pressure carbonization: the carbon layer stack thickness (Lc) is increased by 7.4%, the carbon layer stacking length (La) is increased by 65.7%, and the carbon content % is increased by 2.28%; therefore, it is known according to the present invention. The process can increase the degree of carbonization of the material relative to existing processes at the same processing temperature.

The results of the microstructure analysis can further confirm that the surface resistance of the carbon fiber cloth is reduced by 28.6% (intended to improve the electrical conductivity), and the higher the degree of carbonization, the higher the conductivity.

Because the continuous negative pressure carbonization process will remove the non-carbon elements excluding the material, the carbon fiber cloth ash content is reduced in addition to the increased carbonization degree, and the ash percentage (%) in this example is reduced by 86%.

Although the present invention has been described above in terms of several preferred embodiments, it is not intended to limit the present invention, and it is to be understood that those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Carbonization unit

110‧‧‧Feeding device

111‧‧‧Roller

120‧‧‧ cavity device

125‧‧‧ gas-filled mouth

126‧‧‧Oxygen meter

130‧‧‧Receiving device

140‧‧‧ gas supply unit

121‧‧‧Carbonization unit

122‧‧‧ buffer device

123‧‧‧carbonization chamber

124‧‧‧buffering cavity

150‧‧‧ heat exchanger

160‧‧‧Exhaust device

200‧‧‧ raw materials

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; Schematic diagram of a carbonization unit.

2 is a schematic view showing a continuous negative pressure carbonization apparatus according to a second embodiment of the present invention.

100‧‧‧Carbonization unit

110‧‧‧Feeding device

111‧‧‧Roller

120‧‧‧ cavity device

121‧‧‧Carbonization unit

122‧‧‧ buffer device

123‧‧‧carbonization chamber

124‧‧‧buffering cavity

125‧‧‧ gas-filled mouth

126‧‧‧Oxygen meter

130‧‧‧Receiving device

140‧‧‧ gas supply unit

150‧‧‧ heat exchanger

160‧‧‧Exhaust device

200‧‧‧ raw materials

Claims (14)

A continuous negative pressure carbonization apparatus comprising: at least one feeding device for supplying a raw material; a cavity device for receiving and carbonizing the raw material, and comprising: a carbonization device having a carbonization chamber, the carbonization chamber having a feed port and a discharge port; and two buffering devices respectively connected to the feed port and the discharge port to discharge the gas generated by the carbonization of the raw material in the carbonization chamber, so that the The pressure of the carbonization chamber is maintained at a negative pressure state of greater than 100 Torr and less than one atmosphere; and a receiving device for collecting the carbonized raw material. The continuous negative pressure carbonization device of claim 1, wherein each of the buffer devices comprises a buffer chamber. The continuous negative pressure carbonization device of claim 1, wherein each of the buffer devices comprises a plurality of buffer cavities. The continuous negative pressure carbonization device according to claim 2 or 3, further comprising a gas supply device connected to each of the buffer cavity and the carbonization cavity to respectively supply an inert gas into each of the gas supply chambers a buffer chamber and the carbonization chamber; and an air extraction device connected to the carbonization chamber to extract gas therein. The continuous negative pressure carbonization device according to claim 4, further comprising a heat exchanger disposed between the cavity device and the gas supply device and the air suction device. The continuous negative pressure carbonization device according to claim 2 or 3, further comprising a gas supply device connected to the carbonization chamber to supply an inert gas into the carbonization chamber; and a pumping gas The device is connected to each of the buffer cavity and the carbonization cavity to respectively extract the gas of each of the buffer cavity and the carbonization cavity. The continuous negative pressure carbonization device according to claim 6, further comprising a heat exchanger disposed between the cavity device and the gas supply device and the air suction device. The continuous negative pressure carbonization apparatus of claim 1, wherein the carbonization chamber comprises a gas plenum. The continuous negative pressure carbonization apparatus according to claim 1, wherein the carbonization chamber is provided with an oxygen meter. A continuous negative pressure carbonization method comprising at least: providing a continuous raw material; Carbonizing the raw material by carbonizing the raw material using a carbonization chamber, the carbonization chamber connecting two buffer devices, and when the raw material is carbonized in the carbonization chamber, the buffering device is used in the carbonization chamber due to the raw material The gas generated by the carbonization is discharged, so that the pressure of the carbonization chamber is maintained at a negative pressure state of more than 100 Torr and less than one atmosphere. The continuous negative pressure carbonization method according to claim 10, wherein the carbonization chamber system is subjected to a gas cleaning step before carbonizing the raw material. The continuous negative pressure carbonization method according to claim 10, wherein the carbonization chamber has an oxygen concentration maintained between 1 ppm and 10%. The continuous negative pressure carbonization method according to claim 10, wherein the treatment temperature in the carbonization chamber is between 500 ° C and 1200 ° C. The continuous negative pressure carbonization method according to claim 10, wherein the heating time of the raw material in the carbonization chamber is from 1 minute to 25 minutes.