Device and method for efficiently purifying octafluoropropane

Abstract

The application provides a device for efficiently purifying octafluoropropane, which is divided into three towers, namely, a first heavy component removal tower, a second light component removal tower and a third dehydration tower, wherein the first heavy component removal tower and the second light component removal tower are both composed of an upper tower and a lower tower, and are two-section rectifying towers, and the third dehydration tower is a one-section conventional rectifying tower; liquid phase of the upper tower of the two-section rectifying tower is forcedly transported into the lower tower, and gas phase of the lower tower is spontaneously transported into the upper tower, and the separation effect is significantly higher than that of the conventional rectifying tower; the application also provides a method for efficiently purifying octafluoropropane; crude octafluoropropane in a raw material tank is vaporized by heating and then enters the first heavy component removal tower to remove heavy component impurities; the octafluoropropane preliminarily purified enters the upper tower of the first heavy component removal tower and is collected from the top to enter the second light component removal tower to remove light component impurities; the octafluoropropane purified in two steps enters the third dehydration tower to further remove water, and electronic-grade octafluoropropane gas with a purity greater than 99.999% can be obtained; and the process is simple and the operation condition is mild.

Description

Technical Field

[0001] The invention relates to a high-efficiency purification device and method of octafluoropropane by multi-tower series distillation, belonging to the field of chemical separation. Background Art

[0002] High-purity octafluoropropane (purity greater than 99.999%) is a perfluorinated electronic specialty gas with good stability, excellent insulation, low atmospheric lifetime and efficient etching and cleaning performance. It is currently widely used in industries such as medicine, refrigeration, semiconductors and integrated circuits.

[0003] At present, high-purity octafluoropropane is obtained by combining two or more methods such as distillation, adsorption, impurity conversion and membrane separation to purify it. Chinese patent CN202410202329.X provides a method for purifying octafluoropropane using extractive distillation technology, which includes the following steps: (1) extractive distillation: the extractant and crude octafluoropropane are introduced into an extractive distillation tower together, wherein the mass ratio of crude octafluoropropane to extractant is 1:3-7, and the reflux ratio is 2:1-6; (2) adsorption: the crude octafluoropropane after extractive distillation is introduced into an adsorption tower filled with an adsorbent, the adsorption temperature is 10-30°C, the pressure is 0.1-0.6MPa, and the flow rate is 15-25kg / h to obtain purified octafluoropropane; the adsorbent described in step (2) is a copper salt-doped modified crystalline silica-alumina zeolite molecular sieve adsorbent. The process is relatively complex, requires the addition of an extractant, and has low production efficiency.

[0004] Chinese patent CN202311416436.4 discloses a method for purifying high-purity octafluoropropane, specifically comprising the following steps: first, filtering the unpurified octafluoropropane raw material stored in a storage tank for particles; second, passing the filtered octafluoropropane into a heavy-removal distillation tower for primary distillation to remove heavy impurities in the octafluoropropane; then, passing the octafluoropropane from which the heavy impurities have been removed into a light-removal distillation tower for secondary distillation to remove light impurities in the octafluoropropane; finally, subjecting the octafluoropropane from which the light impurities have been removed to an adsorption operation to obtain high-purity octafluoropropane. Purification processes involving adsorption require activation and regeneration of the adsorbent, and the adsorption capacity of the adsorbent also changes with the continuous purification of the crude product, resulting in poor stability of the entire purification process. Purification processes involving impurity conversion or membrane separation methods have relatively high operating costs.

[0005] Therefore, it is particularly necessary to seek a method for purifying octafluoropropane with simple process and good economic efficiency. Summary of the Invention

[0006] The application aims to provide an efficient purification device and method for octafluoropropane, which has simple process, good stability, effectively removes impurities in octafluoropropane, and finally realizes that the purity of octafluoropropane is greater than 99.999%.

[0007] The application provides the following technical solutions:

[0008] An efficient purification device for octafluoropropane comprises a raw material tank, a first heavy component removal upper column, a first heavy component removal lower column, a heavy component removal reflux pump, a second light component removal upper column, a second light component removal lower column, a light component removal reflux pump, and a third dehydration column.

[0009] The raw material tank is provided with a raw material tank discharge port, the first heavy component removal lower column is provided with a first heavy component removal lower column discharge port, a first heavy component removal lower column reflux inlet, and a first heavy component removal lower column top discharge port, the first heavy component removal upper column is provided with a first heavy component removal upper column inlet, a first heavy component removal upper column top discharge port, and a first heavy component removal upper column bottom discharge port, the second light component removal upper column is provided with a second light component removal upper column inlet, a second light component removal upper column bottom discharge port, and a second light component removal upper column bottom discharge port, and the third dehydration column is provided with a third dehydration column inlet and a third dehydration column discharge port.

[0010] The raw material tank discharge port is connected to the first heavy component removal upper column inlet through a pipeline, the first heavy component removal lower column top discharge port is connected to the first heavy component removal upper column inlet through a pipeline, the first heavy component removal upper column bottom discharge port is connected to the first heavy component removal lower column reflux inlet through a pipeline, the first heavy component removal upper column top discharge port is connected to the second light component removal upper column inlet through a pipeline, the second light component removal upper column bottom discharge port is connected to the second light component removal lower column reflux inlet through a pipeline, the second light component removal lower column top discharge port is connected to the second light component removal upper column inlet through a pipeline, and the second light component removal lower column bottom discharge port is connected to the third dehydration column inlet through a pipeline.

[0011] Preferably, a heavy component removal reflux pump is arranged on the pipeline between the first heavy component removal upper column bottom discharge port and the first heavy component removal lower column reflux inlet, and a light component removal reflux pump is arranged on the pipeline between the second light component removal upper column bottom discharge port and the second light component removal lower column reflux inlet.

[0012] Preferably, a condenser is arranged at the top of the first heavy component removal upper column to provide reflux liquid, a heater is arranged at the bottom of the first heavy component removal lower column to provide ascending gas, a condenser is arranged at the top of the second light component removal upper column to provide reflux liquid, and a heater is arranged at the bottom of the second light component removal lower column to provide ascending gas.

[0013] A method for efficiently purifying octafluoropropane comprises the following steps:

[0014] (1) heating and pressurizing the crude octafluoropropane in the raw material tank;

[0015] (2) The crude gaseous octafluoropropane enters the lower tower of the first-stage deweighting tower through a feed pipeline, and is distilled to remove heavy component impurities, and is extracted from the top of the upper tower of the first-stage deweighting tower; a condenser is provided on the top of the upper tower of the first-stage deweighting tower to provide reflux liquid from the upper tower; a heater is provided in the kettle of the lower tower of the first-stage deweighting tower to provide ascending gas from the lower tower; the reflux liquid of the lower tower of the first-stage deweighting tower is provided by a deweighting reflux pump; the reflux liquid of the upper tower of the first-stage deweighting tower is refluxed to the lower tower of the first-stage deweighting tower;

[0016] (3) The initially purified octafluoropropane is extracted from the top of the first-stage de-heavy tower and enters the second-stage de-light tower, where light component impurities are removed by distillation and extracted from the bottom kettle of the second-stage de-light tower; a condenser is provided on the top of the second-stage de-light tower to provide reflux liquid from the upper tower; a heater is provided in the kettle of the second-stage de-light tower to provide rising gas from the lower tower; the reflux liquid from the second-stage de-light tower is provided by a de-light reflux pump; the reflux liquid from the second-stage de-light tower is refluxed to the second-stage de-light tower;

[0017] (4) After two steps of purification, the octafluoropropane finally enters the third-stage dehydration tower to remove water and obtain electronic grade octafluoropropane gas.

[0018] The main impurities removed by the first-stage deheaving tower are high-boiling-point impurities such as hexafluoropropylene, hexafluoropropane and heptafluoropropane. The main impurities removed by the second-stage delightening tower are low-boiling-point impurities such as nitrogen and hexafluoroethane. The main impurities removed by the third-stage dehydration tower are trace amounts of water impurities.

[0019] Furthermore, prior to purification, the upper and lower towers of the primary dehydration tower, the dehydration reflux pump, the upper and lower towers of the secondary dehydration tower, the dehydration reflux pump, and the tertiary dehydration tower and its piping were purged and replaced. After the entire purification system was tested and qualified, it was pumped down to a negative pressure of -0.1 to -0.095 MPa.

[0020] Furthermore, the bottom temperature of the first-stage deweighting tower is 10-30°C, the top temperature is -20-20°C, the bottom pressure is 0.2-0.5MPa, the top pressure is 0.2-0.5MPa, and the liquid reflux rate is 400-1000kg / h.

[0021] Further preferably, the bottom temperature of the first-stage deweighting tower is -5-25°C, the top temperature is -15-15°C, the bottom pressure is 0.2-0.4 MPa, the top pressure is 0.2-0.4 MPa, and the liquid reflux rate of the first-stage deweighting tower is 600-900 kg / h.

[0022] Furthermore, the bottom temperature of the secondary light-removal tower is 0-30°C, the top temperature is -5-25°C, the bottom pressure is 0.1-0.4MPa, the top pressure is 0.1-0.4MPa, and the liquid reflux rate is 400-1000kg / h.

[0023] Further preferably, the bottom temperature of the secondary light-removal tower is 5-25°C, the top temperature is 0-20°C, the bottom pressure is 0.2-0.35MPa, the top pressure is 0.2-0.35MPa, and the liquid reflux rate of the secondary light-removal tower is 600-900kg / h.

[0024] Furthermore, the bottom temperature of the three-stage dehydration tower is -5-20°C, the top temperature is -10-15°C, the bottom pressure is 0.15-0.3 MPa, and the top pressure is 0.15-0.3 MPa.

[0025] Further preferably, the bottom temperature of the three-stage dehydration tower is 5-20°C, the top temperature is 0-15°C, the bottom pressure is 0.15-0.25 MPa, and the top pressure is 0.15-0.25 MPa.

[0026] Furthermore, both the heavy-gas stripping reflux pump and the light-gas stripping reflux pump are shielded pumps.

[0027] Furthermore, the purity of crude octafluoropropane is 72%-95%, and the purity of electronic grade octafluoropropane gas is 99.999%.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The purification method of the present invention can increase the purity of crude octafluoropropane (content 72%-95%) to above 99.999% by using a single distillation technology, breaking the inherent combination technology purification process of electronic-grade octafluoropropane gas and broadening the purification path of electronic-grade octafluoropropane gas.

[0030] 2. The present invention uses a two-stage distillation tower for the removal of heavy and light gases from electronic-grade octafluoropropane. While achieving superior separation effects, it effectively reduces the required height of the distillation tower, provides convenience for equipment construction, daily operation, inspection and maintenance, and has obvious practical significance.

[0031] 3. The use of single distillation purification technology is conducive to achieving stable control of product quality. The process is simple, has better operability and economy, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a process flow diagram of the present invention.

[0033] In the accompanying drawings, 1-raw material tank, 2-upper tower of the first-stage dehydration tower, 3-lower tower of the first-stage dehydration tower, 4-dehydration reflux pump, 5-upper tower of the second-stage dehydration tower, 6-lower tower of the second-stage dehydration tower, 7-dehydration reflux pump, and 8-tertiary dehydration tower. DETAILED DESCRIPTION

[0034] Equipment Examples

[0035] based on Figure 1 A highly efficient device for purifying octafluoropropane comprises a raw material tank 1, a first-stage dehydration tower 2, a first-stage dehydration tower 3, a dehydration reflux pump 4, a second-stage dehydration tower 5, a second-stage dehydration tower 6, a dehydration reflux pump 7, and a third-stage dehydration tower 8. A condenser is provided at the top of the first-stage dehydration tower 2 to provide reflux liquid from the upper tower, and a heater is provided at the bottom of the first-stage dehydration tower 3 to provide ascending air from the lower tower. A condenser is provided at the top of the second-stage dehydration tower 5 to provide reflux liquid from the upper tower, and a heater is provided at the bottom of the second-stage dehydration tower 6 to provide ascending air from the lower tower. A dehydration reflux pump 4 is provided on the pipeline between the discharge port of the first-stage dehydration tower upper tower and the reflux feed port of the first-stage dehydration tower lower tower, and a dehydration reflux pump 7 is provided on the pipeline between the discharge port of the second-stage dehydration tower upper tower and the reflux feed port of the second-stage dehydration tower lower tower.

[0036] The raw material tank 1 is provided with a raw material tank discharge port, the first-stage deweighting tower lower tower 3 is provided with a first-stage deweighting tower raw material feed port, a first-stage deweighting tower lower tower reflux feed port and a first-stage deweighting tower lower tower top discharge port, the first-stage deweighting tower upper tower 2 is provided with a first-stage deweighting tower upper tower feed port, a first-stage deweighting tower upper tower top discharge port and a first-stage deweighting tower upper tower kettle discharge port, the second-stage delightening tower upper tower 5 is provided with a second-stage delightening tower raw material feed port, a second-stage delightening tower upper tower feed port and a second-stage delightening tower upper tower kettle discharge port, the second-stage delightening tower lower tower 6 is provided with a second-stage delightening tower lower tower kettle discharge port, a second-stage delightening tower lower tower reflux feed port and a second-stage delightening tower lower tower top discharge port, the third-stage dehydration tower 8 is provided with a A three-stage dehydration tower raw material feed port and a three-stage dehydration tower discharge port are provided; the raw material tank discharge port is connected to the raw material feed port of the first-stage dehydration tower through a pipeline, the lower tower top discharge port of the first-stage dehydration tower is connected to the upper tower feed port of the first-stage dehydration tower through a pipeline, the upper tower kettle discharge port of the first-stage dehydration tower is connected to the lower tower reflux feed port of the first-stage dehydration tower through a pipeline, the upper tower top discharge port of the first-stage dehydration tower is connected to the raw material feed port of the second-stage dehydration tower through a pipeline, the upper tower kettle discharge port of the second-stage dehydration tower is connected to the lower tower reflux feed port of the second-stage dehydration tower through a pipeline, the lower tower top discharge port of the second-stage dehydration tower is connected to the upper tower feed port of the second-stage dehydration tower through a pipeline, and the lower tower kettle discharge port of the second-stage dehydration tower is connected to the raw material feed port of the three-stage dehydration tower through a pipeline.

[0037] Example 1-5 provides a method for efficiently purifying octafluoropropane using the equipment of Example 1, with the only difference being the operating conditions. The test results are shown in Table 1.

[0038] Example 1

[0039] (1) Purge and replace the first-stage dehydration tower 2, the first-stage dehydration tower 3, the dehydration reflux pump 4, the second-stage dehydration tower 5, the second-stage dehydration tower 6, the dehydration reflux pump 7, and the third-stage dehydration tower 8 and their pipelines, and maintain pressure and detect leaks. After the entire purification system has passed the inspection, pump it down to a negative pressure of -0.1MPa;

[0040] (2) Wrap the raw material tank 1 with a heating bag with temperature control, turn on the heating, and the raw material is vaporized and pressurized.

[0041] (3) The crude octafluoropropane enters the lower tower 3 of the first de-weighting tower through the feed line, where heavy impurities are removed by distillation. The de-weighted octafluoropropane is produced from the top of the upper tower 2 of the first de-weighting tower. The bottom temperature of the upper tower 2 of the first de-weighting tower and the lower tower 3 of the first de-weighting tower is 5°C, the top temperature is 0°C, the bottom pressure is 0.305 MPa, the top pressure is 0.300 MPa, and the liquid reflux rate is 900 kg / h.

[0042] (4) The initially purified octafluoropropane was withdrawn from the top of the primary deheavy tower 2 and entered the secondary delight tower 5. Light impurities were removed by distillation, and the delighted octafluoropropane was withdrawn from the kettle of the secondary delight tower 6. The kettle temperature of the secondary delight tower 5 and the secondary delight tower 6 was 10°C, the top temperature was 5°C, the kettle pressure was 0.255 MPa, the top pressure was 0.250 MPa, and the liquid reflux rate was 900 kg / h.

[0043] (5) After the two-step purification, the octafluoropropane enters the tertiary dehydration tower 8 for water removal. The distillate sample at the top of the tower is tested, and the fine octafluoropropane is extracted after passing the test. The bottom temperature of the tertiary dehydration tower 8 is 5°C, the top temperature is 0°C, the bottom pressure is 0.205 MPa, and the top pressure is 0.200 MPa.

[0044] Example 2

[0045] (1) Purge and replace the first-stage dehydration tower 2, the first-stage dehydration tower 3, the dehydration reflux pump 4, the second-stage dehydration tower 5, the second-stage dehydration tower 6, the dehydration reflux pump 7, and the third-stage dehydration tower 8 and their pipelines, and maintain pressure and detect leaks. After the entire purification system has passed the inspection, pump it down to a negative pressure of -0.1MPa;

[0046] (2) Wrap the raw material tank 1 with a heating bag with temperature control, turn on the heating, and the raw material is vaporized and pressurized.

[0047] (3) The crude octafluoropropane enters the lower tower 3 of the first de-weighting tower through the feed line, where heavy impurities are removed by distillation. The de-weighted octafluoropropane is withdrawn from the top of the upper tower 2 of the first de-weighting tower. The bottom temperature of the upper tower 2 of the first de-weighting tower and the lower tower 3 of the first de-weighting tower is 5°C, the top temperature is 0°C, the bottom pressure is 0.305 MPa, the top pressure is 0.300 MPa, and the liquid reflux rate is 700 kg / h.

[0048] (4) The initially purified octafluoropropane was withdrawn from the top of the primary deheavy tower 2 and entered the secondary delight tower 5. Light impurities were removed by distillation, and the delighted octafluoropropane was withdrawn from the kettle of the secondary delight tower 6. The kettle temperature of the secondary delight tower 5 and the secondary delight tower 6 was 10°C, the top temperature was 5°C, the kettle pressure was 0.255 MPa, the top pressure was 0.250 MPa, and the liquid reflux rate was 700 kg / h.

[0049] (5) After the two-step purification, the octafluoropropane enters the tertiary dehydration tower to remove water. The distillate sample at the top of the tower is tested, and the fine octafluoropropane is extracted after passing the test. The bottom temperature of the tertiary dehydration tower 8 is 5°C, the top temperature is 0°C, the bottom pressure is 0.205 MPa, and the top pressure is 0.200 MPa.

[0050] Example 3

[0051] (1) Purge and replace the first-stage dehydration tower upper tower 2, the first-stage dehydration tower lower tower 3, the dehydration reflux pump 4, the second-stage dehydration tower upper tower 5, the second-stage dehydration tower lower tower 6, the dehydration reflux pump 7, and the third-stage dehydration tower 8 and their pipelines, and maintain pressure for leak detection. After the entire purification system has passed the inspection, pump it down to a negative pressure of -0.095MPa;

[0052] (2) Wrap the raw material tank 1 with a heating bag with temperature control, turn on the heating, and the raw material is vaporized and pressurized.

[0053] (3) The crude octafluoropropane enters the lower tower 3 of the first de-weighting tower through the feed pipeline, where heavy impurities are removed by distillation. The de-weighted octafluoropropane is withdrawn from the top of the upper tower 2 of the first de-weighting tower. The bottom temperature of the upper tower 2 of the first de-weighting tower and the lower tower 3 of the first de-weighting tower is 5°C, the top temperature is 0°C, the bottom pressure is 0.325 MPa, the top pressure is 0.320 MPa, and the liquid reflux rate is 900 kg / h.

[0054] (4) The initially purified octafluoropropane was withdrawn from the top of the primary deheavy tower 3 and entered the secondary delight tower 5. Light impurities were removed by distillation, and the delighted octafluoropropane was withdrawn from the kettle of the secondary delight tower 6. The kettle temperature of the secondary delight tower 5 and the secondary delight tower 6 was 10°C, the top temperature was 5°C, the kettle pressure was 0.255 MPa, the top pressure was 0.250 MPa, and the liquid reflux rate was 900 kg / h.

[0055] (5) After the two-step purification, the octafluoropropane enters the tertiary dehydration tower 8 for water removal. The distillate sample at the top of the tower is tested, and the fine octafluoropropane is extracted after passing the test. The bottom temperature of the tertiary dehydration tower 8 is 5°C, the top temperature is 0°C, the bottom pressure is 0.205 MPa, and the top pressure is 0.200 MPa.

[0056] Example 4

[0057] (1) Purge and replace the first-stage dehydration tower upper tower 2, the first-stage dehydration tower lower tower 3, the dehydration reflux pump 4, the second-stage dehydration tower upper tower 5, the second-stage dehydration tower lower tower 6, the dehydration reflux pump 7, and the third-stage dehydration tower 8 and their pipelines, and maintain pressure for leak detection. After the entire purification system has passed the inspection, pump it down to a negative pressure of -0.098 MPa;

[0058] (2) Wrap the raw material tank 1 with a heating bag with temperature control, turn on the heating, and the raw material is vaporized and pressurized.

[0059] (3) The crude octafluoropropane enters the lower tower 3 of the first de-weighting tower through the feed line, where heavy impurities are removed by distillation. The de-weighted octafluoropropane is produced from the top of the upper tower 2 of the first de-weighting tower. The bottom temperature of the upper tower 2 of the first de-weighting tower and the lower tower 3 of the first de-weighting tower is 5°C, the top temperature is 0°C, the bottom pressure is 0.305 MPa, the top pressure is 0.300 MPa, and the liquid reflux rate is 900 kg / h.

[0060] (4) The initially purified octafluoropropane was withdrawn from the top of the primary deheavy tower 2 and entered the secondary delight tower 5. Light impurities were removed by distillation, and the delighted octafluoropropane was withdrawn from the kettle of the secondary delight tower 6. The kettle temperature of the secondary delight tower 5 and the secondary delight tower 6 was 10°C, the top temperature was 5°C, the kettle pressure was 0.275 MPa, the top pressure was 0.270 MPa, and the liquid reflux rate was 900 kg / h.

[0061] (5) After the two-step purification, the octafluoropropane enters the tertiary dehydration tower 8 for water removal. The distillate sample at the top of the tower is tested, and the fine octafluoropropane is extracted after passing the test. The bottom temperature of the tertiary dehydration tower 8 is 5°C, the top temperature is 0°C, the bottom pressure is 0.205 MPa, and the top pressure is 0.200 MPa.

[0062] Example 5

[0063] (1) Purge and replace the first-stage dehydration tower 2, the first-stage dehydration tower 3, the dehydration reflux pump 4, the second-stage dehydration tower 5, the second-stage dehydration tower 6, the dehydration reflux pump 7, and the third-stage dehydration tower 8 and their pipelines, and maintain pressure and detect leaks. After the entire purification system has passed the inspection, pump it down to a negative pressure of -0.1MPa;

[0064] (2) Wrap the raw material tank 1 with a heating bag with temperature control, turn on the heating, and the raw material is vaporized and pressurized.

[0065] (3) The crude octafluoropropane enters the lower tower 3 of the first de-weighting tower through the feed line, where heavy impurities are removed by distillation. The de-weighted octafluoropropane is produced from the top of the upper tower 2 of the first de-weighting tower. The bottom temperature of the upper tower 2 of the first de-weighting tower and the lower tower 3 of the first de-weighting tower is 5°C, the top temperature is 0°C, the bottom pressure is 0.305 MPa, the top pressure is 0.300 MPa, and the liquid reflux rate is 900 kg / h.

[0066] (4) The initially purified octafluoropropane was withdrawn from the top of the primary deheavy tower 2 and entered the secondary delight tower 5. Light impurities were removed by distillation, and the delighted octafluoropropane was withdrawn from the kettle of the secondary delight tower 6. The kettle temperature of the secondary delight tower 5 and the secondary delight tower 6 was 10°C, the top temperature was 5°C, the kettle pressure was 0.255 MPa, the top pressure was 0.250 MPa, and the liquid reflux rate was 900 kg / h.

[0067] (5) After the two-step purification, the octafluoropropane enters the tertiary dehydration tower 8 for water removal. The distillate sample at the top of the tower is tested, and the fine octafluoropropane is extracted after passing the test. The bottom temperature of the tertiary dehydration tower 8 is 5°C, the top temperature is 0°C, the bottom pressure is 0.185 MPa, and the top pressure is 0.180 MPa.

[0068] Table 1 Test results of Examples 1-5

[0069]

[0070] The above descriptions are only five embodiments of the present invention. Any simple modification or replacement based on the present invention is within the scope of protection of the present invention.

Claims

1. A device for efficiently purifying octafluoropropane, characterized in that: Including raw material tank, first-stage dehydration tower upper tower, first-stage dehydration tower lower tower, dehydration reflux pump, second-stage dehydration tower upper tower, second-stage dehydration tower lower tower, dehydration reflux pump and third-stage dehydration tower; The raw material tank is provided with a raw material tank discharge port, the lower tower of the first-level deweighting tower is provided with a first-level deweighting tower raw material feed port, a first-level deweighting tower lower tower reflux feed port and a first-level deweighting tower lower tower top discharge port, the upper tower of the first-level deweighting tower is provided with a first-level deweighting tower upper tower feed port, a first-level deweighting tower upper tower top discharge port and a first-level deweighting tower upper tower kettle discharge port, the upper tower of the second-level delightening tower is provided with a second-level delightening tower raw material feed port, a second-level delightening tower upper tower feed port and a second-level delightening tower upper tower kettle discharge port, the lower tower of the second-level delightening tower is provided with a second-level delightening tower lower tower kettle discharge port, a second-level delightening tower lower tower reflux feed port and a second-level delightening tower lower tower top discharge port, and the tertiary dehydration tower is provided with a tertiary dehydration tower raw material feed port and a tertiary dehydration tower discharge port; The discharge port of the raw material tank is connected to the raw material feed port of the first-level de-weighting tower through a pipeline, the discharge port of the lower tower top of the first-level de-weighting tower is connected to the feed port of the upper tower of the first-level de-weighting tower through a pipeline, the discharge port of the upper tower kettle of the first-level de-weighting tower is connected to the reflux feed port of the lower tower of the first-level de-weighting tower through a pipeline, the discharge port of the upper tower top of the first-level de-weighting tower is connected to the raw material feed port of the second-level de-lighting tower through a pipeline, the discharge port of the upper tower kettle of the second-level de-lighting tower is connected to the reflux feed port of the lower tower of the second-level de-lighting tower through a pipeline, the discharge port of the lower tower top of the second-level de-lighting tower is connected to the feed port of the upper tower of the second-level de-lighting tower through a pipeline, and the discharge port of the lower tower kettle of the second-level de-lighting tower is connected to the raw material feed port of the tertiary dehydration tower through a pipeline; A condenser is set on the top of the upper tower of the first-stage deheavy tower to provide reflux liquid for the upper tower, and a heater is set on the kettle of the lower tower of the first-stage deheavy tower to provide rising gas for the lower tower; a condenser is set on the top of the upper tower of the second-stage delightening tower to provide reflux liquid for the upper tower, and a heater is set on the kettle of the lower tower of the second-stage delightening tower to provide rising gas for the lower tower.

2. The device for efficiently purifying octafluoropropane according to claim 1, characterized in that: A de-heavy reflux pump is provided on the pipeline between the discharge port of the upper kettle of the first de-heavy tower and the reflux feed port of the lower tower of the first de-heavy tower, and a de-light reflux pump is provided on the pipeline between the discharge port of the upper kettle of the second de-light tower and the reflux feed port of the lower tower of the second de-light tower.

3. A method for efficiently purifying octafluoropropane, using the device for efficiently purifying octafluoropropane according to any one of claims 1 to 2, characterized in that: The specific steps are as follows: (1) heating and pressurizing the crude octafluoropropane in the raw material tank; (2) The crude gaseous octafluoropropane enters the lower tower of the first-stage deweighting tower through the feed pipeline, and the heavy component impurities are removed by distillation and extracted from the top of the upper tower of the first-stage deweighting tower; the reflux liquid from the upper tower of the first-stage deweighting tower is refluxed to the lower tower of the first-stage deweighting tower; (3) The initially purified octafluoropropane is extracted from the top of the first heavy removal tower and enters the second light removal tower. The light component impurities are removed by distillation and then extracted from the bottom of the second light removal tower. The reflux liquid from the second light removal tower is refluxed to the bottom of the second light removal tower. (4) After two steps of purification, the octafluoropropane finally enters the third-stage dehydration tower to remove water and obtain electronic grade octafluoropropane gas.

4. A method for efficiently purifying octafluoropropane according to claim 3, characterized in that: Before purification, the upper tower of the first-stage deheavy removal tower, the lower tower of the first-stage deheavy removal tower, the deheavy removal reflux pump, the upper tower of the second-stage deheavy removal tower, the lower tower of the second-stage deheavy removal tower, the deheavy removal reflux pump, and the tertiary dehydration tower and its pipelines are purged and replaced. After the entire purification system is tested and qualified, it is pumped to a negative pressure of -0.1 to -0.095MPa.

5. The method for efficiently purifying octafluoropropane according to claim 3, wherein: The bottom temperature of the first-stage deweighting tower is 10-30°C, the top temperature is -20-20°C, the bottom pressure is 0.2-0.5MPa, the top pressure is 0.2-0.5MPa, and the liquid reflux rate is 400-1000kg / h.

6. The method for efficiently purifying octafluoropropane according to claim 3, wherein: The bottom temperature of the secondary light-removal tower is 0-30°C, the top temperature is -5-25°C, the bottom pressure is 0.1-0.4MPa, the top pressure is 0.1-0.4MPa, and the liquid reflux rate is 400-1000kg / h.

7. The method for efficiently purifying octafluoropropane according to claim 3, wherein: The bottom temperature of the three-stage dehydration tower is -5-20°C, the top temperature is -10-15°C, the bottom pressure is 0.15-0.3MPa, and the top pressure is 0.15-0.3MPa.

8. The method for efficiently purifying octafluoropropane according to claim 3, wherein: Both the heavy-weight removal reflux pump and the light-weight removal reflux pump are shielded pumps.

9. The method for efficiently purifying octafluoropropane according to claim 3, wherein: The purity of crude octafluoropropane is 72%-95%, and the purity of electronic grade octafluoropropane gas is 99.999%.

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