Multistage fractionation regenerating device for heat conducting oil
By using a multi-stage fractionation and regeneration device for heat transfer oil, combined with vacuum distillation and pressure filtration technology, the problem of reduced heat transfer performance caused by scaling, coking, and deterioration of heat transfer oil has been solved. This has enabled rapid purification and regeneration of heat transfer oil, improving production stability and ease of maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TIANJIN DAGU CHEM CO LTD
- Filing Date
- 2025-08-18
- Publication Date
- 2026-08-04
AI Technical Summary
In existing ABS production systems, the heat transfer performance of the heat transfer oil deteriorates due to scaling, coking, and deterioration products, affecting the stable operation of the equipment. Furthermore, existing regeneration devices cannot effectively remove the crystallized deposits in the heat transfer oil.
A multi-stage fractionation regeneration device for heat transfer oil is designed. By combining vacuum distillation and pressure filtration, low-boiling substances, insoluble high-boiling substances, and deteriorated products are separated. The effective components are recovered using multi-stage fractionation technology, and crystallized precipitates are removed by a pressure filter, thereby regenerating the heat transfer oil.
It enables rapid purification and regeneration of heat transfer oil, improves production stability and maintenance convenience, ensures that production units do not need to be shut down, and enhances the sensitivity and accuracy of process parameter monitoring.
Smart Images
Figure CN224585374U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of heat transfer oil regeneration technology, specifically relating to a multi-stage fractionation regeneration device for heat transfer oil suitable for SAN production units in ABS production systems. Background Technology
[0002] In existing styrene-acrylonitrile-butadiene terpolymer (ABS) production systems, the styrene-acrylonitrile copolymer (SAN) production unit requires heat transfer oil to heat the heater to remove unreacted monomers. As production time increases, the synthetic heat transfer oil used in the ABS system's SAN production unit gradually exhibits scaling and coking, affecting system heat transfer and failing to meet the optimal temperature for stable production. Therefore, the ABS system's SAN production unit needs a multi-stage fractionation and regeneration unit to treat the deteriorated heat transfer oil and meet the process requirements of the SAN production unit.
[0003] The active ingredient in the heat transfer oil in the SAN production unit is dehydrogenated terphenyl. Long-term use will produce low-boiling substances (short-chain substances produced by cracking and pyrolysis, which cannot withstand high temperatures due to their low boiling points), insoluble high-boiling substances (coking and residual carbon produced due to the high local temperature of the heater exceeding the temperature limit of the heat transfer oil), and deterioration products (mainly para-terphenyl and tetraphenyl, which exist in a crystalline state at low temperatures, affecting the normal operation of the unit).
[0004] The regeneration unit operates on the principle of vacuum distillation, removing low-boiling-point substances, insoluble high-boiling-point substances, and deteriorated products from the heat transfer oil while retaining the undegraded effective components. Therefore, theoretically, the composition of the regenerated heat transfer oil is the same as that of the new heat transfer oil. However, a certain amount of deteriorated products remain in the system's heat transfer oil. These substances can crystallize at low temperatures, affecting the normal operation of the unit. Therefore, to solve the crystal precipitation problem after recovery, a pressure filtration process is added to the recovered finished oil to separate the crystals and prevent them from settling in the heat transfer oil system, thus affecting the normal operation of the unit. Therefore, this invention designs a multi-stage fractionation regeneration unit for heat transfer oil that meets existing operating conditions, has excellent regeneration effect, is easy to transport, and is easy to maintain. Utility Model Content
[0005] The purpose of this invention is to provide a multi-stage fractionation and regeneration device for heat transfer oil, thereby solving the problem that heat transfer oil deteriorates and cannot be used after long-term use.
[0006] The present invention relates to a multi-stage fractionation and regeneration device for heat transfer oil, comprising a hot oil heat exchanger 1, a distillation kettle 2, a condenser 3, a heavy component collection tank 5, a first finished oil tank 6, a second finished oil tank 7, a low-boiling-point tank 8, a gear pump 9, a diaphragm pump 10, a filter press 11, a vacuum pump condenser 12, a vacuum pump inlet buffer tank 13, a second Roots vacuum pump 14, a first Roots vacuum pump 15, a hot oil flow regulating valve 16, a hot oil circulation pump 20, a cooling water tank 21, a first filter 22, a second filter 23, a first Laval nozzle 24, a second Laval nozzle 25, a first jet pump 26, a second jet pump 27, and a sheet metal drum or ton drum 28.
[0007] The hot oil flow regulating valve 16 and the hot oil circulation pump 20 are connected between the hot oil heat exchanger 1 and the distillation vessel 2, which is a jacketed distillation vessel. The function of the hot oil heat exchanger 1 is to heat the hot oil, maintaining its temperature at 0–340°C. The function of the hot oil flow regulating valve 16 is to regulate the flow rate of the hot oil within the jacket of the distillation vessel 2. The function of the hot oil circulation pump 20 is to circulate the hot oil within the jacket of the distillation vessel 2. By adjusting the temperature of the hot oil in the hot oil heat exchanger 1, the hot oil flow regulating valve 16, and the hot oil circulation pump 20, the heating rate of the modified heat transfer oil in the distillation vessel 2 can be adjusted, maintaining its temperature at 0–280°C. The modified heat transfer oil, in the distillation process… Fractional distillation occurs in distillation vessel 2, depending on the volatility differences (i.e., different boiling points) of the components in the deteriorated heat transfer oil. As the temperature rises, the low-boiling-point substances in the deteriorated heat transfer oil are vaporized first, followed by the effective components (dehydro-terphenyl) and deterioration products. The insoluble high-boiling-point substances, as heavy components, remain in the liquid phase of distillation vessel 2. A small amount of organic waste gas is generated during the heating process of distillation vessel 2. The condenser 3 condenses the low-boiling-point substances volatilized from the deteriorated heat transfer oil in distillation vessel 2 and the regenerated finished oil (containing the effective component dehydro-terphenyl and deterioration products). The heavy component collection tank 5 collects the insoluble high-boiling-point substances in the deteriorated heat transfer oil. The first finished oil tank 6 and the second finished oil tank... The function of pump 7 is to collect recycled finished oil; the function of low-boiling matter tank 8 is to collect low-boiling matter; the function of gear pump 9 is to transport the recycled finished oil from the first finished oil tank 6 and the second finished oil tank 7, and the low-boiling matter from the low-boiling matter tank 8, to the tin drum or ton container 28; the function of diaphragm pump 10 is to transport the recycled finished oil to filter press 11, and the function of filter press 11 is to crystallize and separate the deteriorated products in the recycled finished oil; the function of vacuum pump condenser 12 is to perform secondary condensation of a very small amount of uncondensed gas phase after passing through condenser 3 and to pre-cool the organic waste gas; the function of vacuum pump inlet buffer tank 13 is to perform gas-liquid separation; the function of the second Roots vacuum pump 14 and the first Roots vacuum pump 15 is to pump... The organic waste gas is discharged, providing a negative pressure environment for the entire regeneration unit; the function of the first filter 22 and the second filter 23 is to filter water vapor in the exhaust gas from the outlet of the second Roots vacuum pump 14 and the first Roots vacuum pump 15; the function of the first Laval nozzle 24 and the second Laval nozzle 25 is to increase the flow rate of the exhaust gas from the outlet of the second Roots vacuum pump 14 and the first Roots vacuum pump 15; the function of the first jet pump 26 and the second jet pump 27 is to spray cooling ammonia water to denitrify the exhaust gas in the first Laval nozzle 24 and the second Laval nozzle 25; the function of the cooling water tank 21 is to store and cool the circulating ammonia water; and the function of the iron drum or ton drum 28 is to collect and transfer low-boiling substances and regenerated finished oil.
[0008] A pressure-replenishing valve 18, an vent valve C, and a condenser inlet valve 17 are installed at the top of the distillation vessel 2. The distillation vessel 2 is connected to the condenser 3 through the condenser inlet valve 17. The function of the pressure-replenishing valve 18 is to increase the pressure of the distillation vessel 2 in the final stage of the reaction, thereby reducing the boiling point of the deteriorated heat transfer oil and increasing the yield. The inlet flow rate of the condenser 3 is controlled by the condenser inlet valve 17. The condenser 3 is then connected to the first finished oil tank 6, the second finished oil tank 7, and the low-boiling matter tank 8, respectively. An oil replenishment valve 19 is provided on the upper side of the distillation vessel 2, which is used to add 3000-3300L of deteriorated heat transfer oil to be treated into the distillation vessel 2 before the regeneration device described in this utility model starts working. A heavy component discharge valve 4 is provided on the lower side of the distillation vessel 2, and the distillation vessel 2 is connected to the heavy component collection tank 5 through the heavy component discharge valve 4.
[0009] A condensate inlet valve A, a vapor phase outlet valve B, and a vent valve C are respectively installed on the tops of the first finished oil tank 6, the second finished oil tank 7, and the low-boiling-point tank 8. A discharge valve D is installed at the bottom of the first finished oil tank 6, the second finished oil tank 7, and the low-boiling-point tank 8. The first finished oil tank 6, the second finished oil tank 7, and the low-boiling-point tank 8 are all of the same specifications. To prevent overpressure in the tanks during the regeneration of deteriorated heat transfer oil, the condensate inlet valve A and the vapor phase outlet valve B must be opened simultaneously. The vent valve C is used to deal with emergencies such as rapid increase in tank pressure. Under normal circumstances, the vent valve C is normally closed; the discharge valve D is normally closed during non-discharge periods. The discharge valve D is connected to the gear pump 9. When discharging, the discharge valve D is opened to send the material to the gear pump 9. The gear pump 9 is then connected to the tin drum or ton drum 28. The tin drum or ton drum 28 is then connected to the diaphragm pump 10 and the filter press 11 in sequence. The gas phase outlet valve B is connected to the vacuum pump condenser 12. The vacuum pump condenser 12 is connected to the vacuum pump inlet buffer tank 13. The vacuum pump inlet buffer tank 13 is connected to the second Roots vacuum pump 14 and the first Roots vacuum pump 15 respectively.
[0010] When the modified heat transfer oil in distillation vessel 2 is heated to 85-95°C, the low-boiling substances in the modified heat transfer oil begin to volatilize, generating low-boiling substance vapor. At this time, the condenser inlet valve 17, the condensate inlet valve A of the low-boiling substance tank 8, and the vapor outlet valve B are opened, while the condensate inlet valve A and the vapor outlet valve B of the first finished oil tank 6 and the second finished oil tank 7 are closed. This allows the low-boiling substance vapor to be condensed into liquid through condenser 3 and collected in the low-boiling substance tank 8, and finally sent to the iron drum or ton container 28 for collection. When the modified heat transfer oil in distillation vessel 2 is heated to 150-170°C and maintained for 20-30 minutes, the low-boiling substances in the modified heat transfer oil are completely removed. Then, the first... The condensate inlet valve A and vapor phase outlet valve B of the finished oil tank 6 are closed, and the condensate inlet valve A and vapor phase outlet valve B of the low-boiling matter tank 8 are closed, allowing the distilled regenerated heat transfer oil to be collected in the first finished oil tank 6. If the first finished oil tank 6 is full during this period, the condensate inlet valve A and vapor phase outlet valve B of the second finished oil tank 7 are opened, and the condensate inlet valve A and vapor phase outlet valve B of the first finished oil tank 6 are closed to continue collecting the regenerated heat transfer oil. When the deteriorated heat transfer oil in the distillation kettle 2 is heated to 250-270°C and maintained for 20-30 minutes, the condensate inlet valve A and vapor phase outlet valve B of the second finished oil tank 7 are closed to complete the collection of the regenerated heat transfer oil.
[0011] After the regenerated heat transfer oil collection is completed, close the condenser inlet valve 17 and open the heavy component discharge valve 4. Insoluble high-boiling-point substances in the deteriorated heat transfer oil of the distillation kettle 2 are then introduced into the heavy component collection tank 5 via the heavy component discharge valve 4 for collection. At this point, the removal of insoluble high-boiling-point substances is complete. Low-boiling-point substances in the low-boiling-point tank 8, due to their good fluidity, need to be collected in a metal drum or ton container 28 via a gear pump 9. The low-boiling-point substances in the metal drum or ton container 28 and the insoluble high-boiling-point substances in the heavy component collection tank 5 are subsequently treated as hazardous chemical waste.
[0012] After the first finished oil tank 6 or the second finished oil tank 7 is full, the discharge valve D of the first finished oil tank 6 or the second finished oil tank 7 is opened, and the regenerated heat transfer oil is transported to the tin drum or ton 28 by the gear pump 9. The above fractionation process can only remove low-boiling and insoluble high-boiling substances from the deteriorated heat transfer oil, but cannot remove the deteriorated products. The deteriorated products have a high solubility in the high-temperature regenerated heat transfer oil, so the regenerated heat transfer oil in the first finished oil tank 6 and the second finished oil tank 7 needs to be transported to the tin drum or ton 28 for storage. Alternatively, the drum 28 can be placed outdoors and cooled to room temperature after 8 to 12 hours depending on the weather. At this time, the deteriorated products will precipitate as white deteriorated product crystals in the iron drum or drum 28. Then, the diaphragm pump 10 is used to extract the regenerated heat transfer oil from the iron drum or drum 28 and send it to the filter press 11. The filter press 11 removes the deteriorated product crystals by physical extrusion, leaving them in the filter cloth. The regenerated heat transfer oil after the deteriorated products are removed meets the usage standards and can be used as new heat transfer oil, thus completing the multi-stage fractionation regeneration of the heat transfer oil.
[0013] The heat transfer oil regeneration system consists of a hot oil heat exchanger 1, a distillation kettle 2, a condenser 3, a heavy component collection tank 5, a first finished oil tank 6, a second finished oil tank 7, a low-boiling-point tank 8, a gear pump 9, a diaphragm pump 10, a filter press 11, a sheet metal drum or ton drum 28, a hot oil flow regulating valve 16, a condenser inlet valve 17, a pressure replenishing valve 18, a replenishing oil valve 19, and a hot oil circulation pump 20.
[0014] The first Roots vacuum pump 15, the first filter 22, the first Laval nozzle 24, and the cooling water tank 21 are connected in sequence, and the first jet pump 26 is connected between the first Laval nozzle 24 and the cooling water tank 21, forming a normal exhaust gas treatment system. The second Roots vacuum pump 14, the second filter 23, the second Laval nozzle 25, and the cooling water tank 21 are connected in sequence, and the second jet pump 27 is connected between the second Laval nozzle 25 and the cooling water tank 21, forming a backup exhaust gas treatment system. When the regeneration rate is low, the exhaust gas treatment system is designed for "one in use and one in standby" operation; when the regeneration rate is high, the exhaust gas treatment systems can be activated simultaneously.
[0015] This invention utilizes multi-stage fractionation to recover low-boiling substances and effective components, thereby removing insoluble high-boiling substances and deteriorated products. After the regenerated heat transfer oil is cooled, the deteriorated products crystallize out and are then filtered to achieve the purpose of heat transfer oil regeneration.
[0016] The beneficial effects of this utility model are: it can quickly purify and regenerate deteriorated heat transfer oil; furthermore, through the setting and control of digital instruments, it can improve the sensitivity and accuracy of process parameter monitoring; making batch purification more efficient, faster and more convenient; during the heat transfer oil regeneration process, the production unit does not need to be shut down, which improves production stability and the operability of future maintenance and repair work. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of a multi-stage fractionation and regeneration unit for heat transfer oil. Detailed Implementation
[0018] Example 1
[0019] like Figure 1As shown, the names of each part are: hot oil heat exchanger 1, distillation kettle 2, condenser 3, heavy component discharge valve 4, heavy component collection tank 5, first finished oil tank 6, second finished oil tank 7, low boiling point tank 8, gear pump 9, diaphragm pump 10, filter press 11, vacuum pump condenser 12, vacuum pump inlet buffer tank 13, second Roots vacuum pump 14, first Roots vacuum pump 15, hot oil flow regulating valve 16, condenser inlet valve 17, pressure replenishing valve 18, oil replenishing valve 19, hot oil circulation pump 20, cooling water tank 21, first filter 22, second filter 23, first Laval nozzle 24, second Laval nozzle 25, first jet pump 26, second jet pump 27, and tin drum or ton drum 28.
[0020] The distillation vessel 2 is made of stainless steel, is a vertical tank with a volume of 11.35 cubic meters, and has a rated working pressure of 5-8 kPa. The heavy component discharge valve 4 is a 3-inch ball valve.
[0021] The first finished oil tank 6, the second finished oil tank 7, and the low-boiling point tank 8 are made of 304 stainless steel, and level sight glasses are installed at the top and middle of the finished oil tank and the low-boiling point tank. The volume is 3.25 cubic meters. The condensate inlet valve A, the gas phase outlet valve B, the vent valve C, and the discharge valve D are 2-inch ball valves. The pipes used for connecting the equipment are required to be made of 20g material and comply with GB713-1997 standard.
[0022] The second Roots vacuum pump 14 and the first Roots vacuum pump 15 are model 2BEA-25322B-O, with a processing capacity of 1280 (m³ / s). 3 / h); Condenser 3 is a shell-and-tube type with a heat exchange area of 9.45m². 2 The shell side is cooled by water at 5-20℃; the hot oil heat exchanger 1 is a coil-type gas-fired hot oil heater that uses natural gas to heat the hot oil in the coil, with a temperature range of 0-340℃ and a heat exchange area of 4.45m². 2 The filter press is a plate and frame filter press with a processing capacity of 2000L / H.
[0023] Figure 1 The working process of a multi-stage fractionation and regeneration device for heat transfer oil is as follows:
[0024] Before the unit starts working, confirm that the condensate inlet valve A, vapor phase outlet valve B, vent valve C and discharge valve D of the first finished oil tank 6 and the second finished oil tank 7 are closed, the condensate inlet valve A and vapor phase outlet valve B of the low boiling material tank 8 are open, the vent valve C and discharge valve D are closed, and the condenser inlet valve 17, pressure replenishing valve 18, oil replenishing valve 19 and heavy component discharge valve 4 are closed.
[0025] Start the first Roots vacuum pump 15 and control the pressure to 0.098 MPa; open the condenser inlet valve 17, and the vacuum gauge pressure of the distillation vessel 2 is 0.0013~0.2013 MPa. The vent valve C and the pressure replenishing valve 18 are automatically controlled. Open the oil replenishing valve 19 to inject 3200L of cooled modified heat transfer oil into the distillation vessel 2 from the production unit; start the hot oil heat exchanger 1 and control the modified heat transfer oil in the distillation vessel 2 to start heating from 40°C through the flow regulating valve 16. As the temperature rises, the low-boiling substances in the modified heat transfer oil in the distillation vessel 2 begin to vaporize. The vaporized low-boiling substance vapor is condensed into liquid low-boiling substances by the condenser 3 under the action of the first Roots vacuum pump 15 and then enters the low-boiling substance tank 8 for collection; when the low-boiling substance tank 8 is full, close the condensate inlet valve A and the gas phase outlet valve B of the low-boiling substance tank 8, open the discharge valve D, and discharge the low-boiling substances to the iron drum or ton container 28.
[0026] After the heat transfer oil in distillation vessel 2 is heated to 163°C and maintained at that temperature for 25 minutes, no more condensate is produced in the sight glass of low-boiling matter tank 8. At this point, a total of 460L of low-boiling matter has been collected, and the removal of low-boiling matter in distillation vessel 2 is complete. Then, the condensate inlet valve A and vapor outlet valve B of the first finished oil tank 6 are opened, and the condensate inlet valve A and vapor outlet valve B of the low-boiling matter tank 8 are closed. Distillation vessel 2 is continuously heated to begin collecting regenerated heat transfer oil. When the first finished oil tank 6 is full, the condensate inlet valve A and vapor outlet valve B of the second finished oil tank 7 are opened, and the condensate inlet valve A and vapor outlet valve B of the first finished oil tank 6 are closed, switching to collecting regenerated heat transfer oil from the second finished oil tank 7. After the heat transfer oil in distillation vessel 2 reaches a temperature of 268°C under continuous heating for 30 minutes, no more condensate is produced in the sight glass of the second finished oil tank 7. At this point, a total of 4120L of regenerated heat transfer oil has been collected, and the fractionation of the heat transfer oil is complete.
[0027] Open the discharge valve D of the first finished oil tank 6 and the second finished oil tank 7, and transport the regenerated heat transfer oil in the tank to the iron drum or ton drum 28 for collection via gear pump 9. Use 24 200L iron drums to store the regenerated heat transfer oil. After standing for 13 hours, cool it to 25°C. At this time, the heat transfer oil in the iron drum or ton drum 28 is transported to the filter press 11 by diaphragm pump 10 for extrusion to remove the deteriorated product crystals. A total of 365KG of deteriorated product crystals are removed. The heat transfer oil obtained after crystal removal is 3714L, which can be used as new heat transfer oil for the production of the unit.
[0028] The organic waste gas in the distillation kettle 2, along with a very small amount of uncondensed gas phase after passing through the condenser 3, is sent to the vacuum pump condenser 12 for secondary condensation via the gas phase outlet valve B of the first finished oil tank 6, the second finished oil tank 7, and the low-boiling matter tank 8. The gas phase is cooled to 25°C and then sent to the vacuum pump inlet buffer tank 13 for gas-liquid separation. The first Roots vacuum pump 15 (or the second Roots vacuum pump 14) provides a negative pressure environment for the entire regeneration unit. The small amount of organic waste gas in the vacuum pump inlet buffer tank 13 is sent to the first Laval nozzle 24 (or the second Laval nozzle 25) after passing through the first filter 22 (or the first filter 23). After being accelerated by the first Laval nozzle 24 (or the second Laval nozzle 25), it is mixed with the ammonia water injected by the first jet pump 26 (or the second jet pump 27) for flue gas denitrification. The ammonia water injected by the first injection pump 26 (or the second injection pump 27) comes from the cooling water tank 21. The injected ammonia water will also return to the cooling water tank 21. The ammonia water in the cooling water tank 21 can also reduce the temperature of the exhaust gas. The mass fraction of the ammonia water is 18-25%, and the temperature is 10-25℃. Finally, the ammonia water in the cooling water tank 21 is treated as hazardous chemical waste.
Claims
1. A multi-stage fractional distillation regeneration apparatus for heat transfer oil, characterized by: The system consists of a hot oil heat exchanger (1), a distillation kettle (2), a condenser (3), a heavy component collection tank (5), a first finished oil tank (6), a second finished oil tank (7), a low-boiling point tank (8), a gear pump (9), a diaphragm pump (10), a filter press (11), a vacuum pump condenser (12), a vacuum pump inlet buffer tank (13), a second Roots vacuum pump (14), a first Roots vacuum pump (15), a hot oil flow regulating valve (16), a hot oil circulation pump (20), a cooling water tank (21), a first filter (22), a second filter (23), a first Laval nozzle (24), a second Laval nozzle (25), a first jet pump (26), and a second jet pump. (27) and a tin drum or ton drum (28); a hot oil flow regulating valve (16) and a hot oil circulation pump (20) are connected between the hot oil heat exchanger (1) and the distillation kettle (2). A condenser inlet valve (17) is provided at the top of the distillation kettle (2). The distillation kettle (2) is connected to the condenser (3) through the condenser inlet valve (17). The condenser (3) is connected to the first finished oil tank (6), the second finished oil tank (7) and the low-boiling matter tank (8) respectively. A replenishing oil valve (19) is provided at the upper side of the distillation kettle (2). A heavy component discharge valve (4) is provided at the lower side of the distillation kettle (2). The distillation kettle (2) is connected to the heavy component collection tank through the heavy component discharge valve (4). (5) Connection; A condensate inlet valve (A), a vapor phase outlet valve (B), and a vent valve (C) are respectively installed on the top of the first finished oil tank (6), the second finished oil tank (7), and the low-boiling-point tank (8). A discharge valve (D) is installed at the bottom of the first finished oil tank (6), the second finished oil tank (7), and the low-boiling-point tank (8); the discharge valve (D) is connected to a gear pump (9), which is then connected to a sheet metal drum or ton drum (28), which is then connected to a diaphragm pump (10) and a filter press (11) in sequence; the vapor phase outlet valve (B) is connected to a vacuum pump condenser (12), which is connected to a vacuum pump inlet buffer tank (13), and the vacuum pump condenser (12) is connected to a vacuum pump inlet buffer tank (13). The pump inlet buffer tank (13) is connected to the second Roots vacuum pump (14) and the first Roots vacuum pump (15) respectively; the first Roots vacuum pump (15), the first filter (22), the first Laval nozzle (24) and the cooling water tank (21) are connected in sequence, and the first jet pump (26) is connected between the first Laval nozzle (24) and the cooling water tank (21) to form a common exhaust gas treatment system; the second Roots vacuum pump (14), the second filter (23), the second Laval nozzle (25) and the cooling water tank (21) are connected in sequence, and the second jet pump (27) is connected between the second Laval nozzle (25) and the cooling water tank (21) to form a backup exhaust gas treatment system.
2. A multi-stage fractional distillation regeneration apparatus for heat transfer oil as claimed in claim 1, characterized by: The distillation vessel (2) is a jacketed distillation vessel.
3. A multi-stage fractional distillation regeneration apparatus for heat transfer oil as claimed in claim 1, characterized in that: A pressure relief valve (18) and a vent valve (C) are provided on the top of the distillation vessel (2).
4. A multi-stage fractional distillation regeneration apparatus for heat transfer oil as claimed in claim 1, characterized in that: An evacuation valve (C) is installed on the top of the first finished oil tank (6), the second finished oil tank (7), and the low-boiling-point tank (8), and a discharge valve (D) is installed at the bottom of the first finished oil tank (6), the second finished oil tank (7), and the low-boiling-point tank (8).
5. A multi-stage fractional distillation regeneration apparatus for heat transfer oil as claimed in claim 1, characterized in that: Level sight glasses are provided at the top and middle of the first finished oil tank (6), the second finished oil tank (7), and the low-boiling-point tank (8).
6. A multi-stage fractional oil regenerating apparatus according to claim 1, wherein: The hot oil heat exchanger (1) is a coil-type gas-fired hot oil heater.
7. A multi-stage fractional oil regenerating apparatus according to claim 1, wherein: The condenser (3) is a shell-and-tube type.
8. A multi-stage fractional distillation regeneration apparatus for heat transfer oil as claimed in claim 1, characterized by: The filter press is a plate and frame filter press.