Online oil heating method for catalytic slurry oil carbon black production line

Abstract

The invention discloses an online oil heating method for a catalytic slurry oil carbon black production line, which comprises the following steps: 1) flue gas of the carbon black production line is shunted to a first heat exchanger and a second heat exchanger by using a first three-way regulating valve, the first heat exchanger is used for heating conduction oil, and the second heat exchanger is used for heating slurry oil after filtering a catalyst; (2) a flue gas outlet of the first heat exchanger is shunted through a second three-way adjusting valve, part of flue gas flows back to a flue gas pipeline between the first three-way adjusting valve and the second heat exchanger, part of flue gas flows back to the flue gas pipeline between the first three-way adjusting valve and the first heat exchanger through a third three-way adjusting valve; 3) the heat conduction oil in the first heat exchanger and a third heat exchanger form heat conduction oil circulation, and the third heat exchanger is used for heating the catalytic slurry oil on the front side of the first filter.By means of the heating method, local overheating and coking of the catalytic slurry oil can be effectively avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic oil slurry reprocessing equipment, in particular to an online oil heating method for a catalytic oil slurry carbon black production line. Background Art

[0002] In petroleum refining production, catalytic cracking is the main means of producing light oil products. The catalytic cracking reaction will produce catalytic oil slurry, that is, oil slurry containing catalyst. These oil slurries are often initially sold at a low price as waste oil, or burned as fuel, with low utilization rate and reduced returns.

[0003] In order to increase the added value of products in the prior art, these catalytic oil slurries are used to produce carbon black, thereby increasing the added value of products and increasing economic benefits. The production of carbon black from catalytic oil slurry first requires the use of a first filter to remove the solid catalyst in the catalytic oil slurry, and then heating it to 330-360°C and entering the distillation tower for distillation. After distillation, the oil for carbon black production and other products are separated, and then the carbon black production oil is used for carbon black production. Since the viscosity of the catalytic oil slurry itself is relatively high, it is difficult for the catalytic oil slurry at low temperature to filter the solid catalyst in the first filter, so it is generally heated to increase its fluidity before filtering.

[0004] In the process of carbon black production, flue gas with a temperature of about 600°C will be discharged. Naturally, the flue gas generated in the process of carbon black production is used to heat the catalytic oil slurry to about 360°C using a heat exchanger. The heated catalytic oil slurry enters the first filter to filter out the catalyst. The filtered oil slurry is directly passed into the distillation tower for distillation at 330-360°C, thereby effectively utilizing the flue gas heat and saving energy.

[0005] However, in the actual processing process, since the temperature of the flue gas is not stable and will fluctuate within a certain range, it is easy to cause local overheating, causing the catalytic oil slurry in the heat exchanger to coke due to local overheating, and it is easy to cause the heat exchanger and the first filter to be blocked or the flow rate to be too small, requiring frequent decoking, which seriously affects production efficiency. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides an online oil heating method for a catalytic oil slurry carbon black production line, which can effectively avoid the problem of local overheating and coking of the catalytic oil slurry during the heat exchange process caused by unstable flue gas temperature.

[0007] In order to solve the above technical problems, the present invention is solved by the following technical solutions: an online oil heating method for a catalytic oil slurry carbon black production line, comprising the following steps: 1) the flue gas of the carbon black production line is diverted to the first heat exchanger and the second heat exchanger by using a first three-way regulating valve, the first heat exchanger is used to heat the heat transfer oil, and the second heat exchanger is used to heat the oil slurry after filtering the catalyst; 2) the flue gas outlet of the first heat exchanger is diverted by using a second three-way regulating valve, part of the flue gas flows back to the flue gas pipeline between the first three-way regulating valve and the second heat exchanger, and the second three-way regulating valve is adjusted online according to the flue gas temperature to adjust the flue gas temperature entering the second heat exchanger, the flue gas outlet of the first heat exchanger is diverted by using a third three-way regulating valve, part of the flue gas flows back to the flue gas pipeline between the first three-way regulating valve and the first heat exchanger, and the third three-way regulating valve is adjusted online according to the flue gas temperature to adjust the flue gas temperature entering the first heat exchanger; 3) the heat transfer oil in the first heat exchanger forms a heat transfer oil circulation with the third heat exchanger, and the third heat exchanger is used to heat the catalytic oil slurry on the front side of the first filter. This online oil heating method for a catalytic oil slurry carbon black production line diverts the flue gas from the carbon black production line, with one part used to heat the heat transfer oil and the other part used to heat the oil slurry after filtering the catalyst. The catalytic oil slurry is heated by the heat transfer oil to improve its fluidity so that the solid catalyst can be filtered out by the filter. Since the heat transfer oil has good thermal stability and heat transfer properties during heat exchange, local overheating and coking of the catalytic oil slurry can be effectively avoided. The flue gas from the carbon black production line and the flue gas discharged from the first heat exchanger are respectively controlled to mix into the flue gas duct between the first three-way regulating valve and the second heat exchanger and mix into the flue gas duct between the first three-way regulating valve and the first heat exchanger according to the flue gas temperatures of the two, through the online flow regulation of the second three-way regulating valve and the third three-way regulating valve, and the amount of flue gas mixed after heat exchange and cooling in the first heat exchanger is controlled stably, thereby stably controlling the flue gas temperature entering the first heat exchanger and the second heat exchanger. Specifically, when the flue gas temperature of the carbon black production line decreases, the mixing amount of the flue gas discharged from the first heat exchanger is reduced, and when the flue gas temperature of the carbon black production line increases, the mixing amount of the flue gas discharged from the first heat exchanger is increased, thereby effectively avoiding The problem of oil slurry coking during heat exchange between flue gas and filtered oil slurry is avoided. Since heat transfer oil generally exceeds 300°C, it will oxidize, crack and carbonize due to excessive temperature, and it is impossible to heat the catalytic oil slurry to 330-360°C required for subsequent distillation at one time. The present invention first heats the heat transfer oil, and the catalytic oil slurry is heated by the heat transfer oil. The flue gas after the heating of the heat transfer oil is cooled to regulate and stabilize the flue gas heated by the heat transfer oil and the flue gas heated by the filtered oil slurry. The flue gas heated by the filtered oil slurry continues to heat the catalytic oil slurry to 330-360°C required for subsequent distillation, thereby avoiding the problem of local overheating of the catalytic oil slurry and coking during the heat exchange process caused by unstable flue gas temperature.

[0008] In the above technical solution, preferably, the step is included: 4) the flue gas discharged from the second heat exchanger and another part of the flue gas discharged from the second three-way regulating valve are used to preheat the catalytic slurry in the catalytic slurry storage tank. By using the flue gas discharged from the second heat exchanger and another part of the flue gas discharged from the second three-way regulating valve to preheat the catalytic slurry in the catalytic slurry storage tank, the temperature of the catalytic slurry in the catalytic slurry storage tank is increased, the fluidity thereof is improved, and the energy of the delivery pump is saved.

[0009] In the above technical solution, preferably, the third heat exchanger heats the catalytic slurry oil to 270-280° C., and the second heat exchanger heats the slurry oil to 330-360° C. Since heat transfer oil generally exceeds 300° C., it will cause oxidation, cracking, and carbon deposition due to excessive temperature. Therefore, the third heat exchanger heats the catalytic slurry oil to 270-280° C., and the second heat exchanger heats the slurry oil to 330-360° C. so that the slurry oil can be directly introduced into the distillation kettle for reaction.

[0010] In the above technical solution, preferably, a heating jacket is provided in the catalytic oil slurry storage tank, and the flue gas discharged from the second heat exchanger and another part of the flue gas discharged from the second three-way regulating valve pass through the heating jacket to preheat the catalytic oil slurry in the catalytic oil slurry storage tank.

[0011] In the above technical solution, preferably, the flue gas after passing through the catalytic oil slurry storage tank is discharged after waste heat recovery and tail gas treatment.

[0012] In the above technical scheme, preferably, the catalytic oil slurry storage tank is connected to the first filter via the first heat exchanger, the outlet of the first filter is connected to the distillation tower via the second heat exchanger, the outlet of the first filter is also connected to the backwash oil slurry storage tank, the backwash oil slurry storage tank is connected to the backwash port of the first filter, the sewage outlet of the first filter is connected to the sewage storage tank, the sewage storage tank and the backwash oil slurry storage tank are connected via the second filter, when backwashing is performed, the oil inlet and outlet of the first filter are closed, the oil slurry in the backwash oil slurry storage tank is passed into the backwash port, and discharged to the sewage storage tank together with the filter residue through the sewage outlet, the oil slurry containing the filter residue in the sewage tank is filtered by the second filter, and the oil slurry is returned to the backwash oil slurry storage tank. This connection method allows the oil slurry filtered by the first filter to enter the backwash oil slurry storage tank for storage. When the first filter needs to be backwashed, the backwash port is passed into the backwash oil slurry storage tank, and the filter residue is discharged to the sewage storage tank through the sewage outlet. The oil slurry containing the filter residue in the sewage storage tank is filtered by the second filter and the oil slurry is returned to the backwash oil slurry storage tank, making it more convenient to flush the first filter, and the flushing oil can be reused. When the second filter is disassembled to remove the filter residue, the use of the first filter is not affected.

[0013] In the above technical solution, preferably, a heating jacket is provided in the backwash oil slurry storage tank, and the flue gas discharged from the second heat exchanger or another part of the flue gas discharged from the second three-way regulating valve passes through the heating jacket to keep the oil slurry in the backwash oil slurry storage tank warm. Passing the flue gas through the backwash oil slurry storage tank can keep the oil slurry in the backwash oil slurry storage tank warm, so that it maintains good fluidity, so that the flushing operation does not need to heat the oil slurry.

[0014] In the above technical solution, preferably, a heat transfer oil heating device is provided on the heat transfer oil circulation. By providing the heat transfer oil heating device, auxiliary heating can be performed when the flue gas temperature is insufficient to heat the heat transfer oil to a set temperature, so as to stabilize the heat transfer oil to a set temperature.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the online oil heating method for the catalytic oil slurry carbon black production line diverts the flue gas of the carbon black production line, one part of which is used to heat the heat transfer oil, and the other part is used to heat the oil slurry after filtering the catalyst. The catalytic oil slurry is heated by the heat transfer oil to improve its fluidity so that the solid catalyst can be filtered out by the filter. Since the heat transfer oil has good thermal stability and heat transfer during heat exchange, the local overheating and coking of the catalytic oil slurry can be effectively avoided. According to the flue gas temperature, the first three-way regulating valve is adjusted online to adjust the temperature of the heat transfer oil entering the first heat exchanger to stabilize the temperature of the heat transfer oil, that is, when the flue gas temperature decreases, the flue gas flow entering the first heat exchanger is increased, and when the flue gas temperature increases, the flue gas flow entering the first heat exchanger is reduced, thereby stabilizing the temperature of the heat transfer oil. However, since the heat transfer oil generally exceeds 300°C, it will oxidize, crack and carbonize due to excessive temperature, so it is impossible to heat the catalytic oil slurry to the temperature required for subsequent distillation at one time. 330-360℃; further, part of the flue gas cooled by the first heat exchanger is returned to the flue gas duct between the first three-way regulating valve and the second heat exchanger, and the second three-way regulating valve is adjusted online according to the flue gas temperature to adjust the flue gas temperature entering the second heat exchanger, that is, according to the flue gas temperature of the carbon black production line and the cooled flue gas temperature at the outlet of the second heat exchanger, the second three-way regulating valve is adjusted online to make part of the cooled flue gas at the outlet of the second heat exchanger mixed with the original flue gas between the first three-way regulating valve and the second heat exchanger, so that the temperature of the flue gas entering the first heat exchanger can always be stable, thereby effectively avoiding the problem of coking of the oil slurry when the flue gas exchanges heat with the filtered oil slurry; the flue gas discharged from the second heat exchanger and the other part of the flue gas discharged from the second three-way regulating valve are used to preheat the catalytic oil slurry in the catalytic oil slurry storage tank, so that the temperature of the catalytic oil slurry in the catalytic oil slurry storage tank is increased, its fluidity is improved, and the energy of the delivery pump is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Figure 1 , Figure 1 The three flow paths of flue gas, heat transfer oil and catalytic oil slurry are shown in the figure, where the solid line represents the flow path of the catalytic oil slurry, the uneven dotted line represents the flow path of the flue gas, and the uniform dotted line represents the flow path of the heat transfer oil circulation.

[0018] A method for online oil heating of a catalytic oil slurry carbon black production line comprises the following steps: 1) using a first three-way regulating valve 1 to divert flue gas from the carbon black production line to a first heat exchanger 2 and a second heat exchanger 3, wherein the first heat exchanger 2 is used to heat the heat transfer oil, and the second heat exchanger 3 is used to heat the oil slurry after filtering the catalyst; 2) using a second three-way regulating valve 4 to divert the flue gas outlet of the first heat exchanger 2, and part of the flue gas flows back to the flue gas pipeline between the first three-way regulating valve 1 and the second heat exchanger 3, and adjusting the flue gas temperature online according to the flue gas temperature. The second three-way regulating valve 4 is used to adjust the flue gas temperature entering the second heat exchanger 3. The flue gas outlet of the first heat exchanger 2 is diverted by the third three-way regulating valve 5. Part of the flue gas flows back to the flue gas pipeline between the first three-way regulating valve 1 and the first heat exchanger 2. According to the flue gas temperature, the third three-way regulating valve 5 is adjusted online to adjust the flue gas temperature entering the first heat exchanger 2; 3) The heat transfer oil in the first heat exchanger 2 forms a heat transfer oil cycle with the third heat exchanger 6. The third heat exchanger 6 is used to heat the catalytic oil slurry on the front side of the first filter. This catalytic oil slurry carbon black production line online oil heating method diverts the flue gas of the carbon black production line, one part is used to heat the heat transfer oil, and the other part is used to heat the oil slurry after filtering the catalyst. The catalytic oil slurry is heated by the heat transfer oil to improve its fluidity so that the solid catalyst can be filtered out by the filter. Since the heat transfer oil has good thermal stability and heat transfer during heat exchange, it effectively avoids the situation of local overheating and coking of the catalytic oil slurry. The flue gas of the carbon black production line and the flue gas discharged from the first heat exchanger 2 are respectively controlled to mix into the flue gas pipeline between the first three-way regulating valve 1 and the second heat exchanger 3 and the flue gas pipeline between the first three-way regulating valve 1 and the first heat exchanger 2 according to the flue gas temperatures of the two, through the second three-way regulating valve 4 and the third three-way regulating valve 5, and the amount of flue gas mixed after heat exchange and cooling in the first heat exchanger 2 is controlled stably, so as to stably control the flue gas temperature entering the first heat exchanger 2 and the second heat exchanger 3. Specifically, when the flue gas temperature of the carbon black production line decreases, the mixing amount of the flue gas discharged from the first heat exchanger 2 is reduced, and when the flue gas temperature of the carbon black production line increases, the mixing amount of the flue gas discharged from the first heat exchanger 2 is increased. Furthermore, the problem of oil slurry coking during heat exchange between flue gas and filtered oil slurry is effectively avoided. Since heat transfer oil generally exceeds 300°C, it will oxidize, crack and carbonize due to excessive temperature, and it is impossible to heat the catalytic oil slurry to 330-360°C required for subsequent distillation at one time. The present invention first heats the heat transfer oil, and the catalytic oil slurry is heated by the heat transfer oil. The flue gas after the heating of the heat transfer oil is cooled to regulate and stabilize the flue gas heated by the heat transfer oil and the flue gas heated by the filtered oil slurry. The flue gas heated by the filtered oil slurry continues to heat the catalytic oil slurry to 330-360°C required for subsequent distillation, thereby avoiding the problem of local overheating of the catalytic oil slurry and coking during the heat exchange process due to unstable flue gas temperature.

[0019] In order to detect the temperature of the internal flue gas, the flue gas duct shall be provided with a necessary temperature sensor, in order to control the flow direction of the flue gas, a necessary one-way valve shall be provided, and in order to conveniently control the flue gas flow, a flow meter shall be provided. The openings of the first three-way regulating valve 1, the second three-way regulating valve 4 and the third three-way regulating valve 5 are calculated by the control device based on the induced temperature of the temperature sensor. The first three-way regulating valve 1, the second three-way regulating valve 4 and the third three-way regulating valve 5 are preferably solenoid valves, and their openings are controlled online by the control device, so as to stably control the temperature entering the first heat exchanger 2 and the second heat exchanger 3; similarly, the delivery line of the catalytic oil slurry shall also be provided with a necessary delivery pump, and the delivery pump is preferably a screw extrusion pump. In order to conveniently control the temperature of the catalytic oil slurry, a temperature sensor shall also be provided on the delivery line of the catalytic oil slurry.

[0020] In order to reduce the viscosity of the catalytic oil slurry in the catalytic oil slurry storage tank 7 and facilitate pumping, the method further includes the following steps: 4) the flue gas discharged from the second heat exchanger 3 and another part of the flue gas discharged from the second three-way regulating valve 4 are used to preheat the catalytic oil slurry in the catalytic oil slurry storage tank 7. By using the flue gas discharged from the second heat exchanger 3 and another part of the flue gas discharged from the second three-way regulating valve 4 to preheat the catalytic oil slurry in the catalytic oil slurry storage tank 7, the temperature of the catalytic oil slurry in the catalytic oil slurry storage tank 7 is increased, the fluidity thereof is improved, and the energy of the delivery pump is saved.

[0021] In this embodiment, the third heat exchanger 6 heats the catalytic slurry to 270-280° C., and the second heat exchanger 3 heats the slurry to 330-360° C. Since heat transfer oil generally exceeds 300° C., it will cause oxidation, cracking, and carbon deposition due to excessive temperature. Heat transfer oil with better quality can work at a maximum of about 330° C. In order to avoid oxidation, cracking, and carbon deposition caused by excessively high temperature of heat transfer oil, the third heat exchanger 6 heats the catalytic slurry to 270-280° C., and the second heat exchanger 3 heats the slurry to 330-360° C. so that the slurry can be directly introduced into the distillation kettle for reaction.

[0022] In this embodiment, in order to conveniently preheat the catalytic oil slurry in the catalytic oil slurry storage tank 7, a heating jacket is provided in the catalytic oil slurry storage tank 7, and the flue gas discharged from the second heat exchanger 3 and another part of the flue gas discharged from the second three-way regulating valve 4 pass through the heating jacket to preheat the catalytic oil slurry in the catalytic oil slurry storage tank 7.

[0023] In this embodiment, in order to further utilize the waste heat in the flue gas and avoid environmental pollution, the flue gas after passing through the catalytic oil slurry storage tank 7 is discharged after waste heat recovery and tail gas treatment.

[0024] In this embodiment, the catalytic oil slurry storage tank 7 is connected to the first filter 8 via the first heat exchanger 2, the outlet of the first filter 8 is connected to the distillation tower via the second heat exchanger 3, and the outlet of the first filter 8 is also connected to the backwash oil slurry storage tank 9, the backwash oil slurry storage tank 9 is connected to the backwash port of the first filter 8, the sewage outlet of the first filter 8 is connected to the sewage storage tank 10, and the sewage storage tank 10 is connected to the backwash oil slurry storage tank 9 via the second filter 11. When backwashing is performed, the oil inlet and outlet of the first filter 8 are closed, and the oil slurry in the backwash oil slurry storage tank 9 is passed into the backwash port, and discharged together with the filter residue to the sewage storage tank 10 through the sewage outlet, and the oil slurry containing the filter residue in the sewage storage tank 10 is filtered by the second filter 11 and the oil slurry is returned to the backwash oil slurry storage tank 9. This connection method allows the oil slurry filtered by the first filter 8 to be stored in the backwash oil slurry storage tank 9. When the first filter 8 needs to be backwashed, the backwash port is passed into the backwash oil slurry storage tank 9, and the filter residue is discharged to the sewage storage tank 10 through the sewage outlet. The oil slurry containing the filter residue in the sewage storage tank 10 is filtered by the second filter 11 and the oil slurry is returned to the backwash oil slurry storage tank 9, making it more convenient to flush the first filter 8, and the flushing oil can be reused. When the second filter 11 is disassembled to remove the filter residue, it does not affect the use of the first filter 8. It is easy for those skilled in the art to understand that in order to realize the above operation process, a number of valves need to be provided on the connecting pipes between the first filter 8, the backwash oil slurry storage tank 9, the sewage storage tank 10 and the second filter 11.

[0025] In this embodiment, a heating jacket is provided in the backwash oil slurry storage tank 9, and the flue gas discharged from the second heat exchanger 3 or another part of the flue gas discharged from the second three-way regulating valve 4 passes through the heating jacket to insulate the oil slurry in the backwash oil slurry storage tank 9. Passing the flue gas through the backwash oil slurry storage tank 9 can insulate the oil slurry in the backwash oil slurry storage tank 9, so that the fluidity is better, so that the flushing operation does not need to heat the oil slurry.

[0026] In this embodiment, a heat transfer oil heating device 12 is provided on the heat transfer oil circulation. By providing the heat transfer oil heating device 12, auxiliary heating can be performed when the flue gas temperature is insufficient to heat the heat transfer oil to a set temperature, so as to stabilize the heat transfer oil to a set temperature. The heat transfer oil heating device 12 is preferably an electrically heated heat transfer oil heater, which can more accurately control the temperature of the heat transfer oil.

[0027] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An online oil heating method for a catalytic oil slurry carbon black production line, characterized in that: The following steps are involved: 1) The flue gas of the carbon black production line is diverted to the first heat exchanger (2) and the second heat exchanger (3) by using a first three-way regulating valve (1), the first heat exchanger (2) is used to heat the heat transfer oil, and the second heat exchanger (3) is used to heat the oil slurry after the catalyst is filtered; 2) The flue gas outlet of the first heat exchanger (2) is diverted by using a second three-way regulating valve (4), and part of the flue gas flows back to the flue gas pipeline between the first three-way regulating valve (1) and the second heat exchanger (3), and the second three-way regulating valve (4) is adjusted online according to the flue gas temperature to adjust the flue gas entering the second heat exchanger (3). The flue gas temperature of the heat exchanger (3) is adjusted, the flue gas outlet of the first heat exchanger (2) is diverted by the third three-way regulating valve (5), part of the flue gas flows back to the flue gas duct between the first three-way regulating valve (1) and the first heat exchanger (2), and the third three-way regulating valve (5) is adjusted online according to the flue gas temperature to adjust the flue gas temperature entering the first heat exchanger (2); 3) the heat transfer oil in the first heat exchanger (2) and the third heat exchanger (6) form a heat transfer oil circulation, and the third heat exchanger (6) is used to heat the catalytic oil slurry on the front side of the first filter (8).

2. The method for online oil heating of a catalytic slurry carbon black production line according to claim 1, characterized in that: The method comprises the following steps: 4) the flue gas discharged from the second heat exchanger (3) and another part of the flue gas discharged from the second three-way regulating valve (4) are used to preheat the catalytic oil slurry in the catalytic oil slurry storage tank (7).

3. The method for online oil heating of a catalytic slurry carbon black production line according to claim 1, characterized in that: The third heat exchanger (6) heats the catalytic oil slurry to 270-280°C, and the second heat exchanger (3) heats the oil slurry to 330-360°C.

4. The method for online oil heating of a catalytic slurry carbon black production line according to claim 2, characterized in that: The catalytic oil slurry storage tank (7) is provided with a heating jacket, and the flue gas discharged from the second heat exchanger (3) and another part of the flue gas discharged from the second three-way regulating valve (4) pass through the heating jacket to preheat the catalytic oil slurry in the catalytic oil slurry storage tank (7).

5. The method for online oil heating of a catalytic slurry carbon black production line according to claim 4, characterized in that: The flue gas after passing through the catalytic oil slurry storage tank (7) is discharged after waste heat recovery and tail gas treatment.

6. The method for online oil heating of a catalytic slurry carbon black production line according to claim 1, characterized in that: The catalytic oil slurry storage tank (7) is connected to the first filter (8) via the first heat exchanger (2), the outlet of the first filter (8) is connected to the distillation tower via the second heat exchanger (3), the outlet of the first filter (8) is also connected to the backwash oil slurry storage tank (9), the backwash oil slurry storage tank (9) is connected to the backwash port of the first filter (8), the sewage outlet of the first filter (8) is connected to the sewage storage tank (10), the sewage storage tank (10) and the backwash oil slurry storage tank (9) are connected via the second filter (11), when backwashing is performed, the oil inlet and outlet of the first filter (8) are closed, the oil slurry in the backwash oil slurry storage tank (9) is passed into the backwash port, and is discharged together with the filter residue into the sewage storage tank (10) through the sewage outlet, the oil slurry containing the filter residue in the sewage storage tank (10) is filtered by the second filter (11), and the oil slurry is returned to the backwash oil slurry storage tank (9).

7. The method for online oil heating of a catalytic slurry carbon black production line according to claim 6, characterized in that: A heating jacket is provided in the backwash oil slurry storage tank (9), and the flue gas discharged from the second heat exchanger (3) or another part of the flue gas discharged from the second three-way regulating valve (4) passes through the heating jacket to keep the oil slurry in the backwash oil slurry storage tank (9) warm.

8. The method for online oil heating in a catalytic slurry carbon black production line according to claim 1, characterized in that: The heat transfer oil circulation is provided with a heat transfer oil heating device (12).

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