CN107541810A - The tracing system of carbon fibre carbonizing furnace exhaust pipeline - Google Patents

Abstract

The invention discloses a heat tracing system for a waste gas pipeline of a carbon fiber carbonization furnace. The heat tracing system includes: a plurality of resistance heaters, which are arranged at intervals on the outer wall of the exhaust gas pipeline, and the distance between adjacent resistance heaters is 100mm-3300mm; an insulation layer, which wraps the exhaust gas pipeline and the resistance heater Carry out heat preservation; and two thermocouples, which are correspondingly arranged on the downstream side of each of the resistance heaters, are responsible for on-site detection as a heat tracing temperature detection point, and convert the detection signal into a temperature transmission signal; the two thermocouples The distance between the couple and the corresponding resistance heater is 200mm-1500mm; the two thermocouples are used for the temperature control circuit and the over-temperature trip protection circuit. The heat tracing system has uniform temperature control, high control precision, easy operation, long service life, no tar condensation in the exhaust gas pipeline, no solid waste accumulation and blockage, which greatly prolongs the effective production and operation cycle of the carbonization furnace.

Description

Heat Tracing System for Carbon Fiber Carbonization Furnace Exhaust Gas Pipeline

technical field

The invention relates to the field of carbon fiber production equipment, in particular to a heat tracing system for an exhaust gas pipeline of a carbon fiber carbonization furnace.

Background technique

The carbonization process of carbon fiber is to produce carbon fiber precursor through pre-oxidation, low-temperature carbonization, high-temperature carbonization, surface treatment, sizing and drying.

In the process of carbon fiber production, the exhaust gas generated by the carbonization furnace is sent to the incinerator through the pipeline for combustion and harmless treatment. Carbonization furnace exhaust gas often condenses tar, waste carbon filaments and other substances in the exhaust gas pipeline, and eventually it is easy to block the exhaust gas pipeline, resulting in forced interruption of carbonization production. The common practice in many similar manufacturers is to use electric heat tracing technology to heat the pipeline by converting electrical energy into heat energy to avoid the formation of tar and the accumulation of solid waste and cause blockage.

The existing heat tracing technology for exhaust gas pipelines is not perfect. After the exhaust gas inside the exhaust gas pipeline is introduced, the exhaust gas fluid has an impact on the temperature of the exhaust gas pipeline, and it is not possible to select the heat tracing temperature detection point of the exhaust gas pipeline well. The selection of parameters such as the size arrangement, protection level, voltage level, and power density of the exhaust gas pipeline resistance heater has not been scientific and reasonable. In the control system, there are problems such as low control accuracy and large temperature fluctuations, which cannot achieve uniform, effective and comprehensive heat tracing.

The information disclosed in this Background section is only for enhancing the understanding of the general background of the present invention and should not be taken as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a heat tracing system of carbon fiber carbonization furnace waste gas pipeline with simple and reasonable structure, the temperature control of the heat tracing system is uniform, the control precision is high, the operation is simple, the service life is long, and there is no tar condensation and no solid in the waste gas pipeline The clogging of waste accumulation greatly prolongs the effective production and operation period of the carbonization furnace.

In order to achieve the above object, the present invention provides a heat tracing system for a carbon fiber carbonization furnace exhaust gas pipeline, comprising: a plurality of resistance heaters arranged at intervals on the outer wall of the exhaust gas pipeline, and the distance between adjacent resistance heaters is 100mm～3300mm; insulation layer, which wraps the exhaust gas pipeline and resistance heater for heat preservation; and two thermocouples, which are correspondingly arranged on the downstream side of each resistance heater, which are responsible for on-site detection as heat tracing temperature detection points , and convert the detection signal into a temperature transmission signal; the distance between the two thermocouples and their corresponding resistance heaters is 200mm to 1500mm; the two thermocouples are used for the temperature control circuit and the over-temperature tripping protection circuit.

Preferably, in the above technical solution, the resistance heater adopts a three-phase 110V-380V AC voltage.

Preferably, in the above technical solution, one end of the exhaust gas pipeline is provided with a connecting flange for connecting the exhaust gas interface introduced by the carbonization furnace, and the other end of the exhaust gas pipeline is provided with a connecting flange for connecting the exhaust gas treatment incinerator Export to incinerator.

Preferably, in the above technical solution, a blind flange of a four-way connector is provided at the corner of the exhaust gas pipeline.

Preferably, in the above technical solution, the temperature control circuit is provided with a PLC module and a power regulator for controlling the normal temperature of the resistance heater; the over-temperature trip protection circuit is provided with a temperature controller and a power circuit breaker for Overtemperature trip protection for resistance heaters.

Compared with the prior art, the present invention has the following beneficial effects: the actual use of the heat tracing system of the exhaust gas pipeline of the carbon fiber carbonization furnace has received very good results, with uniform temperature control (±1°C) and high control accuracy (±1°C) , The heating temperature of the exhaust gas pipeline can be set arbitrarily in the range of 330°C to 680°C. It is easy to operate, has a long life, no tar condensation in the exhaust gas pipeline, and no solid waste accumulation and blockage, which greatly prolongs the effective production and operation cycle of the carbonization furnace.

Description of drawings

Fig. 1 is a structural schematic diagram of a heat tracing system of a carbon fiber carbonization furnace exhaust gas pipeline according to the present invention.

detailed description

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations thereof such as "includes" or "includes" and the like will be understood to include the stated elements or constituents, and not Other elements or other components are not excluded.

As shown in Figure 1, the heat tracing system of the carbon fiber carbonization furnace exhaust gas pipeline according to the specific embodiment of the present invention specifically includes: a resistance heater 1, a double thermocouple 2, an insulation layer 3, a temperature control circuit and an over-temperature tripping protection circuit. Wherein, the resistance heaters 1 are arranged on the outer wall of the waste gas pipeline 4 at intervals, and are wrapped and kept insulated by an insulating layer 3 . According to the difference in the flow velocity of the exhaust gas in the pipeline, two thermocouples 2 are arranged on the downstream side of the resistance heater 1, which are responsible for on-site detection as the heat tracing temperature detection point, and convert the detection signal into a temperature transmission signal. The temperature control circuit is used to control the normal temperature of the resistance heater 1, and the over-temperature trip protection circuit is used for the over-temperature trip protection of the resistance heater 1, so as to ensure the temperature control and operation safety of the exhaust gas pipeline heating system.

Specifically, one end of the exhaust gas pipeline 4 is provided with a connecting flange 12 for connecting the exhaust gas interface introduced by the carbonization furnace, and the other end of the exhaust gas pipeline 4 is provided with a connecting flange 10 for connecting the exhaust gas treatment incinerator to export the exhaust gas to Incinerator. A blind flange of a four-way connector 11 is provided at the corner of the exhaust gas pipeline 4, which is used for checking the accumulation of solid waste inside the exhaust gas pipeline. In special cases, if there is solid waste accumulation, it will be cleaned from here.

There are multiple resistance heaters 1, which are arranged at intervals on the outer wall of the exhaust gas pipeline 4, and are used to convert electric energy into heat energy to heat the pipeline to avoid the formation of tar and the accumulation of solid waste and blockage.

Preferably, the distance b between adjacent resistance heaters 1 is 100 mm to 3300 mm.

Preferably, the resistance heater 1 adopts a three-phase 110V-380V AC voltage, IP65 protection level, a maximum temperature resistance of 1200°C, and a heating power density of 700W-2000W/m2.

The waste gas pipeline 4 and the resistance heater 1 are wrapped and insulated by an insulating layer 3, and the insulating layer 3 includes a high-temperature-resistant insulating material and a foreskin.

The two thermocouples 2 are correspondingly arranged on the downstream side of the resistance heater 1, which are responsible for on-site detection as the heat tracing temperature detection point, and convert the detection signal into a temperature transmission signal. According to the difference in flow velocity of the exhaust gas in the pipeline, the distance a between the two thermocouples 2 and the corresponding resistance heater 1 is 200mm-1500mm.

The double thermocouple 2 has a temperature control circuit and an over-temperature tripping protection circuit. The temperature control circuit is equipped with a PLC module 8 and a power regulator 9 to control the output power of the resistance heater 1, so as to realize the heat tracing of the exhaust gas pipeline. Control at a certain normal temperature, according to the different exhaust gas components, the temperature is controlled at a suitable temperature in the range of 330°C to 680°C. The over-temperature tripping protection circuit is provided with a thermostat 6 and a power circuit breaker 7, which are used for over-temperature tripping protection of the resistance heater 1, so as to ensure temperature control and safe operation of the exhaust gas pipeline heating system. The heat tracing system of the exhaust gas pipeline of the carbon fiber carbonization furnace rises to the set target temperature according to a certain heating rate before the exhaust gas of the carbonization furnace is introduced, and then introduces the exhaust gas after stabilization. After the introduction of exhaust gas from the carbonization furnace is stopped, the temperature is lowered off-line according to a certain cooling rate as required.

In summary, the heat tracing system has uniform temperature control, high control precision, easy operation, long service life, no tar condensation in the exhaust gas pipeline, and no solid waste accumulation and blockage, which greatly prolongs the effective production and operation cycle of the carbonization furnace.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention, as well as various Choose and change. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (5)

1. A kind of 1. tracing system of carbon fibre carbonizing furnace exhaust pipeline, it is characterised in that including：

   Resistance heater, to be multiple, interval is laid in the outer wall of exhaust piping for it, and the spacing of the adjacent resistance heater is 100mm~3300mm；

   Heat-insulation layer, it wraps up the exhaust piping and resistance heater and is incubated；And

   Double thermocouples, it is correspondingly arranged at the downstream of each resistance heater, and it bears as heat tracing temperature detecting point Site Detection is blamed, and detection signal is converted into temperature pick-up signal；The corresponding resistance heater of a double thermocouple Spacing be 200mm~1500mm；A double thermocouple is used for temperature control loop and overtemperature trip protection loop.
2. 2. the tracing system of carbon fibre carbonizing furnace exhaust pipeline according to claim 1, it is characterised in that the resistance adds Hot device uses three-phase 110V~380V alternating voltages.
3. 3. the tracing system of carbon fibre carbonizing furnace exhaust pipeline according to claim 1, it is characterised in that the flue gas leading The one end in road is provided with adpting flange, and for connecting the waste gas interface of carbide furnace importing, the other end of the exhaust piping is set There is adpting flange, export waste gas to incinerator for connecting exhaust-gas treatment incinerator.
4. 4. the tracing system of carbon fibre carbonizing furnace exhaust pipeline according to claim 3, it is characterised in that the flue gas leading The corner in road is provided with the blind flange of four connectors.
5. 5. the tracing system of carbon fibre carbonizing furnace exhaust pipeline according to claim 1, it is characterised in that the temperature control PLC module and power regulating eqiupment are provided with loop processed, for controlling the normal temperature of resistance heater；The overtemperature trip protection returns Road is provided with temperature controller and power circuit breaker, the overtemperature trip protection for resistance heater.