3M/24K CARBON FIBER PRODUCTION LINE

SATURN4505024

 3M/24K CARBON FIBER PRODUCTION LINE

Production Line General Requirements

designed a 3m carbon fiber production line. It uses PAN based precursor as raw material, and the tow specifications are 24K. It carbonizes the precursor to produce high-quality carbon fiber.

2. General description of the line

The carbon fiber production line consists of creel, moisture station, oxidation oven, low-temperature carbonization furnace, high-temperature carbonization furnace, non-contact dryer, sizing machine, winder, driving unit and waste gas treatment system, etc. Whole line will achieve continuous multi heat treatment and subsequent treatment of PAN-based precursor to produce high-performance carbon fibers. It adopts a centralized control system, integrated computer technology, network communication technology and self-diagnosis technology, is a fully automatic continuous carbon fiber production line.

 General parameter Item -Unit -Parameter -Notes

Type of fiber -24K

Linear density -g/m -2.88

Max load of precursor spindle -Kg -300

Oven effective width -mm -3000

Tow distance -mm -12.5

Filaments quantity -Tows -240

Normal process speed -m/min -15

Filament feed per unit time -Kg/h -544 -At 15 m/min speed

Max. mechanical speed -m/min -18 -Calculated at 50Hz

Min. mechanical speed -m/min -5

Annual output -Ton/year -2488 -At 15 m/min speed，7200 hours/year

Oxidation oven

Number of oxidation oven -6

Effective heating length -m -13

Max. temperature -℃ -300

Number of layer -Top 9/Bottom 10

Total heating length -m -741

Oxidation time (at process temperature) -min -61.75 min -At 15 m/min speed

Low temperature carbonizing furnace

Number of temperature zones -7

Maximum design temperature -℃ -1000

Total length of temperature zone -m -1.8×7= 12.6m

Carbonization time -s -63 -At 15 m/min speed

High temperature carbonizing furnace

Number of temperature zones -7

Maximum design temperature -℃ -1800

Total length of temperature zone -m -1.8×7=12.6m

Carbonization time -s -63 -At 15 m/min speed

Part 2. Technical description of each component

1) Creel

Summary

The creel is designed according to 24K precursor, with a maximum weight of 300kg.

The creel unwinds actively. The tension of the tows is controlled by a tension sensor. Single motor controls yarn release speed to ensure constant yarn tension. The system has good response, high control precision, advanced technology and function.

Technology parameter

 Inner diameter of yarn bobbin: Φ144 +/-0.5

External diameter: Φ165+/- 1

Bobbin length: 750mm

Bobbin material: plastic

The largest diameter of precursor yarn spindle: Φ800

The largest weight of precursor yarn spindle: 300kg

Production Speed: 5-18m/min

Number of bobbins: 480(top and bottom each 240)

Tension range: 250-2000cN

Tension fluctuation range (from full bobbin to empty bobbin): ± 5%

Tension fluctuation range after loading: ± 10%

Layer number of loading bobbin: 2*2(Double layer platform)

Column number of loading bobbin: 4

Row number of loading bobbin: 30

Spindle locking: air expansion shaft

Creel motor: servo motor (based on final design)

Power supply: 3 phase 380V 50Hz

Technical performance and characteristics Single motor control unwinding has high control precision and good response；

The tension sensor is used to adjust and control the yarn tension, and the tension control is accurate；

The unwinding motor is equipped with an automatic detachment device. When the motor fails, the yarn can drag the spindle to unwind passively, realizing the automatic release function in case of motor failure; the mechanical damping device is set to prevent the spindle from rotating freely due to the inertia of the spindle;

Air expansion shaft locking precursor yarn spindle. The operation is convenient and fast；

The whole yarn track is a rotating guide roller, and the surface is specially treated；

Central control function:

Emergency stop and spindle shutdown function: emergency stop button is installed in the length direction of the creel to ensure emergency shutdown when necessary; press the off switch at each spindle position to turn off the single spindle function；

The structure of guide roller and collecting rod is optimized to realize multi-direction adjustment, which is conducive to the adjustment of guide roller and wire collecting rod. It can realize no false twist during the operation of the precursor, reduce the contact points on the side of the precursor as far as possible, and reduce the use of the combing brush as far as possible. It is required to strictly control the static balance of all idlers and passive rollers, and carry out special surface treatment

 The setting parameters include unwinding speed and length setting;

Display the alarm information of different spindle positions, including unwinding fault and tension overrun;

The manipulator is used for loading, which is suitable for manual loading of 300kg precursor.

Technical parameters of manipulator

Maximum loading capacity: 300 kg

Number of manipulator: 4 (2 for up, 2 for bottom)

Spindle overturn: 90 degrees

Spindle rotate: 360 degrees

The lifting height is matched with the yarn frame

The lifting speed: 5m/min

The moving direction is vertical and horizontal

Optimization and improvement of manipulator, two manipulators can be concentrated in two channels.

2) Moisture station

Operating principle

The function of the equipment is to soak the precursor tows before entering the oxidation oven. The equipment has ultrasonic humidification function.

Main technology parameter

Driving roller diameter: 273mm

Immersion length: 1000mm (based on final design)

Driving speed: 5-15m/min (50Hz at 15m/min)

Driving motor power: 4KW (based on final design)

Speed control mode: Synchronous motor + frequency transformer

Dimension (L×W×H): 3215×4137×3255mm (based on final design)

Power supply: 3 phase 380V 50Hz

Composition and structure

Bathing pool

Roller set

Press roller

Ultrasound moisture device

Roller set (including driving roller, immersion roller, passive roller)

Press roller

Material: stainless steel - welding piece

Introduction: the bath is used to hold deionized water and control the liquid level to supplement the water absorbed by fibers.

Material: stainless steel hard chrome plating surface treatment

Diameter: Driving roller——273mm

Immersion roller——320mm

Passive roller——273mm

Function: Driving fiber forward into bath

Material: Carbon steel covered with rubber

Diameter: 303mm

Function: It used to press the fiber to limit the amount of water taken away.

The water is atomized into 1-5 micron ultrafine particles by high frequency oscillation of ultrasonic wave, and the water mist is diffused into the air by a pneumatic device, so as to achieve the goal of uniform moisture of the air. It has high humidification intensity, uniform humidification and high humidification efficiency.

The relative moisture of indoor air can be adjusted in the range of 25%-75%.

Main configuration

No. -Name -Specifications -Notes

1 -The ultrasonic generator -Domestic brands

2 -Roller bearing -SKF

3 -Press roller bearing -SKF

4 -Air cylinder -SMC/METALWORK

5 -Driving roller -Φ273AISI304

6 -Passive roller -Φ273AISI 304

7 -Press roller -Q345B coated rubber

8 -Driving motor -SEW/Siemens

9 -Reducer -SEW

10 -Frequency converter -Siemens/Mitsubishi/YASKAWA inverter

3) Oxidation oven

Summary

The oxidation oven system consists of six ovens. According to the technological requirements, the oxidation oven can set different temperatures, that is, six temperature zones for fibers.

Main Technical Parameters (each oven)

Oven dimensions:

Length approx 15,725 mm(based on final design)

Width approx 5,750 mm(based on final design)

Height approx 3,150 mm(based on final design)

Effective furnace width: 1000mm

Number of heating zone: 2

Heating length: 2 x 6,500 = 13,000 mm

Number of pass bottom oven: 10

top oven: 9

Opening height: 50 mm

Air flow direction: center to end horizontal air supply

Max. air velocity in fiber zoom: 3 m/s

Air velocity in fiber zoom: 2.0– 3.5 m/s

Temperature uniformity (without tows):

Maximum lateral deviation (± 2.5℃)

Maximum deviation between up and down (± 2.5℃)

Maximum longitudinal deviation (± 2.5℃)

Airflow uniformity at 3m/s speed each zone ±10%

(under normal temperature)

Circulating air volume in each zone: 115000m³/h

Power of fan motor each zone: 110 kW(based on final design)

Power of fan motor each oven: 220KW

Operating temperature range: 180 - 280 °C

Maximum temperature of circulating air: 300 °C

Heater power of each zone: 460kW

Heater power of each oven: 920kW

The total power of each oven: 1140KW

Surface temperature limit of heater: 490°C.

Heating mode: electric heating

Heat transfer form: convective form

Heating rate: 3°C/min (180°C to 280°C)

Preheating fresh air volume: 2 x1950Nm³/h = 3900Nm³/h

Total preheated fresh air volume (6 ovens): 6 x 2 x 1950Nm³/h=23400Nm³/h

Exhaust gas volume per oven(from oven): 2 x 1950Nm³/h =3900Nm³/h

(from suction hood): 2 x1000Nm³/h=2000Nm³/h

Total exhaust gas volume (6 ovens): 6x（3900+2000）Nm³/h =35400Nm³/h

External surface temperature of oven: max 50 °C

(at 20℃ room temperature, except heat bridges)

Weight of each oven: 40000 kg

Main components Oven body The oven wall plate is composed of 200 mm insulation board. The core material is rock wool, and the panel is aluminized steel plate;

The oven is equipped with a sealed door to enter into the oven for maintenance;

The oven is equipped with entrance door to clean and maintain the system in each chamber;

The oven has thermal expansion compensation measures and the oven wall plate has expansion joints；

The filter net is assembled before the fan. The filter has two insertion ports, one for use, one for spare, to achieve on-line cleaning;

There is a pressure differential monitoring device for filter net to know the blockage situation in time;

Oven body mounted on concrete floor or steel structure (steel structure provided by buyer);

The oven body is equipped with 8 temperature measuring ports, (4 for each heating zone (1 air inlet, 3 air return), 8 for each oven), There are 3 detecting

Oven body

Circulating fan frequency control

Electric heater

Gas seal

Water spray system

The air distribution device in the oven is made of stainless steel plate;

The air duct and structural part in the oven are made of aluminized steel sheet;

The filter net is made of stainless steel and aluminized steel;

detection points in total. There is 1 temperature measuring port at the air inlet vent, 2 temperature detecting points in total; Temperature sensor accuracy class A.

3.2. Low Noise Design of Circulating Fan and Dynamic Balance of Impeller.

3.3. Electric heater has overheating protection, and the maximum heater surface temperature design is about 490℃.

3.4. The function of gas seal is divided into two parts:

3.5. Spray system is divided into the water deluge system and the water fog system; The water deluge system - water is automatically or manually released into the process chamber in case of over-temperature detection inside the tow band. A number of spray nozzles which controlled by electromagnetic valve are installed in the fiber room; And a number of manual spray buttons are set outside the oven body;

The water fog system – is used for rapid cool-down of the oven by automatic release in case of over-temperature detection and/or manual release of the system. It can rapidly cooling the circulating air. The spray nozzle is installed in the front part of the circulating fan. Solenoid valve controls spray water (Deionized water)

3.6. In each zone of Oxdataion oven, one pressure relief panel is forsee.

3.7. The electrical control system includes PLC, frequency converter, power regulator, human machine interface and related control software.(Included in the whole line electric control system)

3.8. The return air chamber filter screen of oxidation oven can be replaced online.

Part 1: Absorbing the air in the oven which is trying to escape and feeding it back into the circulating air. Absorbing part of circulating air at the outlet of the circulating fan to RTO.

Part 2: Sending Preheated air to prevent cold air entering the oven; The amount of entering air can be adjusted out of oven.

The air seal is provided with an suction hood, which is made of aluminized board.

4) Vertical driving device

Working principle

The function of the vertical drive device is to guide the fibers through the oxidation oven and maintain the required tension ratio on the fibers. It is driven by 6 rollers.

Main technical parameters

Driving roller diameter: 273mm

Driving mode: 6-roll drive

Driving speed: 5-15m/min (50Hz at 15m/min )

Speed regulation mod: Synchronous motor + encoder

Driving motor power: 15KW(based on the final design)

Dimension (L×W×H): 1500 mm×4378mm×2595 mm

Power supply: 3 phase 380V 50Hz

(Installed in different positions of the production line, the size of vertical drive device are slightly different)

Main components Roller ,

Press roller ,

Frame  Driving system

Roller

Press roller

Frame

Driving system

Material: carbon steel----Hard chrome plating

Diameter: 273mm

Material: carbon steel covered with rubber

Diameter: 230 mm

Material: painted carbon steel - Weldment

Introduce: frame support roller and drive system

Introduction: the drive system transfers motion and torque from the reducer motor to the roller. Gear transmission is adopted between reducer motor and roller.

Main configuration

No. -Name -Specifications -Notes

1 -Roller bearing -SKF

2 -Press roller bearing -SKF

3 -Air cylinder -METAL WORK or the same grade brand

4 -Roller -φ273，Q345B

5 -Press roller -Q345B Coated rubber

6 -Drive motor -SEW or Siemens

7 -Reducer -SEW

5) Turn back roller

Main configuration

The turn back roller is installed on the steel structure support, which is used for fiber stratification and steering in the oven channel. Rolling bearings and bearing supports are set at both ends of the turn back roller, and the roller rotates passively through fiber dragging. The bearing supports are adjustable, which can be adjusted in two directions.

composition and structure

Pass back roller diameter: 245mm

Effective width: 3000mm

Due to the close distance between the roller and the oxidation oven, and the oxidation reaction is exothermic, the turn back roller may become hot, which reduces the operability of the production line and increases the risk of operators. The return roller is equipped with a cooling system, which will cool the roller through the circulation of cold water to reduce its temperature.

6) Oxidation oven platform

The oxidation oven platform includes two second-layer oxidation ovens, stairs of upper and lower second-layer oxidation ovens, interworking platform between oxidation ovens, protective railings, etc. It doesn’t include a layer of pre-embedded frame and pre-embedded board for oxidation oven foundation.

The platform beam and column of the oxidation oven are welded with H-section steel and bolted connection structure. The surface of the components is sprayed after shot peening and rust removal.

The aisle of oxidation oven platform is paved with galvanized checkered plate, and the safety platform is optimized. The platform is easy to operate and the protection is more reasonable.

7) Low temperature carbonization furnace(LTF)

Summary

The low temperature carbonization furnace is a continuous through alloy muffle furnace, which consists of an inlet airlock, a carburizing furnace body and an outlet airlock. It is used to heat and carbonize the tows.

Main technical parameters Main technical parameters of furnace body

Effective furnace width: 3000mm

The dimension of furnace with inlet and outlet sealing box (cooling):

Length: approx 18300 mm(based on final design)

Width: approx 6000 mm (based on final design)

Height: approx 2810 mm (based on final design)

Muffle internal length: approx 14500 mm

Width: approx 3,050 mm

Height (two side): approx 200 mm

(middle): approx 300 mm

Horizontal height of tows: approx 1,700 mm(±30 mm adjustable)

Number of muffle: 1

Muffle material: 1.4864（330S）

Muffle exhaust vent (two sides):4 x 2 (The opening temperature zone of exhaust port is in the first, second, third and fourth zone)

Heating mode: electric heating

Heater type: Embedded ceramic fiber heater

Number of heating zones: 7 (Independently Controllable Heating Zone)

Number of control zones in each heating zone 1 above the muffle

1 below the muffle Zone No. -Length -Power -Max. temperature

Zone 1 -1800 mm -120kW -500 °C

Zone 2 -1800 mm -100kW -600 °C

Zone 3 -1800 mm -50kW -700 °C

Zone 4 -1800 mm -50kW -800 °C

Zone 5 -1800 mm -100kW -900 °C

Zone 6 -1800 mm -120kW -1000 °C

Zone 7 -1800 mm -150kW -850 °C

Totally 12600mm 690 kW