Intermittent pre-oxidation furnace for mesophase pitch precursor

Abstract

The utility model provides an intermittent pre-oxidation furnace for mesophase pitch precursors. The intermittent pre-oxidation furnace comprises an upper furnace cover, an upper distribution plate, an upper pressure sensor, an upper temperature measuring thermocouple, an upper ventilating pipeline, a hot air circulating fan, a flowmeter 1, a lower ventilating pipeline, a lower pressure sensor, a lower distribution plate, a lower temperature measuring thermocouple, a lower furnace body, a fresh air supplementing fan, a flowmeter 2 and a heater. According to the intermittent pre-oxidation furnace for the mesophase pitch precursor, reaction heat in the pre-oxidation process of the mesophase pitch precursor can be rapidly taken away, the oxygen consumption in the pre-oxidation process of the mesophase pitch precursor is monitored on line, the fresh air flow is automatically adjusted and supplemented, the stable oxygen content in the furnace is ensured, and the production efficiency is improved. And the circulating air volume is automatically adjusted on line, and the mesophase pitch precursor is prevented from being easily polluted by external air in the pre-oxidation process.

Description

TECHNICAL FIELD

[0001] The utility model relates to mesophase pitch based carbon fiber production and manufacturing equipment field, concretely relates to a mesophase pitch original silk intermittent pre-oxidation furnace. BACKGROUND

[0002] Carbon fiber is a kind of high-performance fiber material, and in recent years, it develops very rapidly, and carbon fiber and its composite material have a series of excellent performances such as high specific strength, high specific modulus, high temperature resistance, corrosion resistance, fatigue resistance, creep resistance, electrical conductivity, heat conduction and small thermal expansion coefficient, and as a kind of new material with excellent performance, carbon fiber and its composite material are widely used in aerospace, rail transportation, sports and leisure fields.The preparation process of carbon fiber mainly includes polymerization, preparation of original wire, pre-oxidation, carbonization, surface treatment and winding, and each process has an important influence on the quality of carbon fiber.Carbon fiber original wire is relatively fragile, pre-oxidation refers to the oxidation crosslinking of carbon fiber original wire and air or oxygen at a certain temperature, and the fiber structure of carbon fiber original wire is fixed by oxidation crosslinking, so as not to melt and lose fiber structure when carbon fiber original wire is carbonized, so the carbon fiber oxidation process is also called carbon fiber non-melting process, and it is an indispensable process in carbon fiber production, and it is also a relatively key process in carbon fiber production process, and it is a process with long time and large energy consumption, and pre-oxidation furnace is a key equipment in pre-oxidation process.

[0003] The existing pre-oxidation furnace cannot quickly take away the reaction heat inside the fiber tows during the oxidation process, so that the oxidation degree inside and outside the fiber tows is inconsistent, and the subsequent performance is different.The existing pre-oxidation furnace cannot monitor the oxygen consumption in the furnace in real time, automatically adjust the new air flow in time, and maintain the stability of the oxygen content in the furnace.The pre-oxidation process is easy to be polluted by external air. UTILITY MODEL CONTENT

[0004] The utility model discloses a kind of mesophase pitch original silk intermittent pre-oxidation furnace, and its technical solution to solve technical problem is as follows:

[0005] The intermittent pre-oxidation furnace for mesophase pitch precursor includes an upper furnace cover (1), an upper distribution plate (2), an upper pressure sensor (3), an upper temperature measuring thermocouple (4), an upper ventilation duct (5), a hot air circulating fan (6), a flowmeter 1 (7), a lower ventilation duct (8), a lower pressure sensor (9), a lower distribution plate (10), a lower temperature measuring thermocouple (11), a lower furnace body (12), a new air fan (13), a flowmeter 2 (14), and a heater (15). The upper distribution plate (2) is located on the top of the upper furnace cover (1), the upper pressure sensor (3) is located on the connecting line of the upper furnace cover (1) and the hot air circulating fan (6), the lower pressure sensor (9) is located on the connecting line of the lower furnace body (12) and the hot air circulating fan (6), the upper temperature measuring thermocouple (4) is located below the upper distribution plate (2) on the top of the upper furnace cover (1), the lower temperature measuring thermocouple (11) is located above the lower distribution plate (10), the upper ventilation duct (5) is connected to the heater (15) from the top end of the upper furnace cover (1), the heater (15) is installed on the vertical duct of the outlet of the hot air circulating fan (6), the lower ventilation duct (8) is connected to the hot air circulating fan (6) from the bottom of the lower furnace body (12), the new air fan (13) is connected to the lower ventilation duct (8) through an interface, the flowmeter 1 (7) is located on the vertical duct of the outlet of the hot air circulating fan (6), and the flowmeter 2 (14) is located on the vertical duct of the outlet of the new air fan (13).

[0006] The upper furnace cover can be lifted and lowered by using a pneumatic cylinder. The lower edge of the upper furnace cover is provided with a wind deflector to prevent uneven wind field at the edge of the furnace body.

[0007] Further, the upper distribution plate and the lower distribution plate each have two layers and are each made of two 310S white steel plates with holes of different specifications uniformly distributed. The lower layer of the upper distribution plate is uniformly distributed with holes with a diameter of Φ5 and a hole center distance of 10 mm, and the upper layer of the upper distribution plate is uniformly distributed with holes with a diameter of Φ20 and a hole center distance of 40 mm. The upper layer of the lower distribution plate is uniformly distributed with holes with a diameter of Φ5 and a hole center distance of 10 mm, and the lower layer of the lower distribution plate is uniformly distributed with holes with a diameter of Φ20 and a hole center distance of 40 mm.

[0008] Further, the upper ventilation duct is a white steel corrugated pipe that can be contracted. A Φ10 hole is reserved on the upper ventilation duct, and an electromagnetic valve is installed for connecting an oxygen content analyzer for real-time monitoring of the oxygen content change in the furnace. A Φ40 hole is reserved as a waste gas outlet, and a high-temperature resistant ball valve is installed for discharging part of the exhaust gas in the furnace. The waste gas outlet is connected to a tail gas purification system.

[0009] Further, the hot air circulating fan circulates hot air from top to bottom, and the hot air circulating fan and the outlet are both soft connected. The hot air circulating fan is adjusted by frequency conversion. The pressure difference between the upper pressure sensor in the furnace and the lower pressure sensor in the furnace is set to control the hot air circulating fan and keep the pressure difference in the furnace stable.

[0010] Further, the lower ventilation pipeline is provided with a filter for filtering the broken filaments and the filaments generated in the production process, and the filter is convenient to replace.

[0011] Further, the new air supply fan is a variable frequency regulation type, the frequency of the new air supply fan is controlled by setting the difference value of the two real-time oxygen content analyzers, the oxygen content in the furnace is kept constant, and the new air supply flow is monitored by the flow meter.

[0012] Further, the new air supply fan is a variable frequency regulation type, the frequency of the new air supply fan is controlled by setting the difference value of the two real-time oxygen content analyzers, the oxygen content in the furnace is kept constant, and the new air supply flow is monitored by the flow meter.

[0013] The structure of the utility model is scientific and reasonable, and the online automatic adjustment of the circulating air volume can timely and quickly take away the reaction heat in the intermediate phase pitch raw filament pre-oxidation process. The oxygen consumption in the intermediate phase pitch raw filament pre-oxidation process is monitored online, the new air supply flow is automatically adjusted, the oxygen content in the furnace is ensured to be stable, and the intermediate phase pitch raw filament is prevented from being easily polluted by external air in the pre-oxidation process. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the structure schematic view of the utility model.

[0015] Among them, 1, the upper furnace cover; 2, upper distribution plate; 3, upper pressure sensor; 4, upper temperature measuring thermocouple; 5, upper ventilation pipeline; 6, hot air circulating fan; 7, flow meter 1; 8, lower ventilation pipeline; 9, lower pressure sensor; 10, lower distribution plate; 11, lower temperature measuring thermocouple; 12, lower furnace body; 13, new air supply fan; 14, flow meter 2; 15, heater. DETAILED DESCRIPTION

[0016] The technical scheme of the utility model will be described clearly and completely in combination with the drawings of the utility model.

[0017] The carbon fiber raw filament wound in the previous process is uniformly placed into the filament containing barrel by the filament placing machine, after the filament placing is completed, the upper furnace cover (1) is opened, the filament containing barrel is placed into the furnace body, the upper furnace cover (1) is closed, the pressure difference value of the upper pressure sensor (3) in the furnace and the lower pressure sensor (9) in the furnace is set, the difference value of the two real-time oxygen content analyzers is set, the program temperature is set, the hot air circulating fan (6) is started, the heater (15) is started, the new air supply fan (13) is started, the upper ventilation pipeline (5) waste ball valve is opened, and the equipment automatically heats according to the heating program.

[0018] The upper furnace cover (1) can be lifted and lowered, and a pneumatic cylinder is used.

[0019] The upper distribution plate (2) and the lower distribution plate (10) are both two layers, which are made of 310S white steel plates with two different specifications of uniformly distributed holes, the lower layer of the upper distribution plate (2) is uniformly distributed with holes with a diameter of Φ5 and a hole center distance of 10mm, the upper layer of the upper distribution plate (2) is uniformly distributed with holes with a diameter of Φ20 and a hole center distance of 40mm, the upper layer of the lower distribution plate (10) is uniformly distributed with holes with a diameter of Φ5 and a hole center distance of 10mm, and the lower layer of the lower distribution plate (10) is uniformly distributed with holes with a diameter of Φ20 and a hole center distance of 40mm.

[0020] The upper ventilation pipeline (5) is a white steel corrugated pipe that can be contracted, a Φ10 hole is reserved on the upper ventilation pipeline (5), and an electromagnetic valve is installed for connecting an oxygen content analyzer for real-time monitoring of the change of the oxygen content in the furnace.

[0021] The hot air circulating fan (6) has a hot air circulating direction from top to bottom, the hot air circulating fan (6) and the outlet are both soft connections, and the hot air circulating fan (6) is adjusted in a frequency conversion mode.

[0022] The lower ventilation pipeline (8) is provided with a filter for filtering the broken and loose filaments generated in the production process, and the lower ventilation pipeline (8) is provided with a Φ10 hole and an electromagnetic valve connected with the oxygen content analyzer for real-time monitoring of the change of the oxygen content in the furnace.

[0023] The new air supply fan (13) is adjusted in a frequency conversion mode, the difference between the two real-time oxygen content analyzers is set to control the frequency of the new air supply fan (13) to keep the oxygen content in the furnace constant, and the flow of the new air supply is monitored through the flowmeter (14).

[0024] The new air supply fan (13) is adjusted in a frequency conversion mode, the difference between the two real-time oxygen content analyzers is set to control the frequency of the new air supply fan (13) to keep the oxygen content in the furnace constant, and the flow of the new air supply is monitored through the flowmeter (14).

[0025] The above examples do not limit the utility model in any way, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the utility model.

Claims

1. A batch pre-oxidation furnace for mesophase pitch precursor fibers, characterized in that, The system includes an upper furnace cover (1), an upper distribution plate (2), an upper pressure sensor (3), an upper temperature thermocouple (4), an upper ventilation duct (5), a hot air circulating fan (6), a flow meter 1 (7), a lower ventilation duct (8), a lower pressure sensor (9), a lower distribution plate (10), a lower temperature thermocouple (11), a lower furnace body (12), a fresh air fan (13), a flow meter 2 (14), and a heater (15). The upper distribution plate (2) is located on top of the upper furnace cover (1), the upper pressure sensor (3) is located on the connection line between the upper furnace cover (1) and the hot air circulating fan (6), and the lower pressure sensor (9) is located on the connection line between the lower furnace body (12) and the hot air circulating fan (6). In the wiring circuit, the upper temperature measuring thermocouple (4) is located below the upper distribution plate (2) on the top of the upper furnace cover (1), the lower temperature measuring thermocouple (11) is located above the lower distribution plate (10), the upper ventilation duct (5) is connected to the heater (15) from the top of the upper furnace cover (1), the heater (15) is installed on the vertical pipe of the outlet of the hot air circulation fan (6), the lower ventilation duct (8) is connected to the hot air circulation fan (6) from the bottom of the lower furnace body (12), the fresh air fan (13) is connected to the lower ventilation duct (8) through the interface, the flow meter 1 (7) is located on the vertical pipe of the outlet of the hot air circulation fan (6), and the flow meter 2 (14) is located on the vertical pipe of the outlet of the fresh air fan (13).

2. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The upper furnace cover (1) can be raised and lowered.

3. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The lower edge of the upper furnace cover (1) is provided with an air guide plate.

4. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The upper distribution plate (2) has two layers and is made of 310S stainless steel plates with two different specifications of uniformly distributed apertures.

5. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The upper ventilation duct (5) is a retractable stainless steel corrugated pipe.

6. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The upper ventilation duct (5) has a reserved Φ10 hole and is equipped with a solenoid valve; the upper ventilation duct (5) has a reserved Φ40 hole and is equipped with a high-temperature ball valve.

7. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The hot air circulation fan (6) circulates hot air from top to bottom, and both the hot air circulation fan (6) and its outlet are flexible connections.

8. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The hot air circulating fan (6) is frequency-controlled.

9. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The lower ventilation duct (8) is equipped with a filter.

10. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 7, characterized in that: A Φ10 hole is reserved on the lower ventilation duct (8) and a solenoid valve is installed thereon. A Φ40 hole is reserved for the fresh air inlet.

11. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The lower distribution plate (10) has two layers and is made of 310S stainless steel plates with two different specifications of uniformly distributed apertures.

12. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The fresh air supply fan (13) is frequency converter regulated.

13. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The outlet of the fresh air supply fan (13) is equipped with a flexible connection and a flow meter.

14. The intermittent pre-oxidation furnace for mesophase pitch precursor fibers according to claim 1, characterized in that: The fresh air supply fan (13) has a filter at its inlet.

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