A distillation separation device and method for recovering tetrahydrofuran

Abstract

The present invention relates to the technical field of tetrahydrofuran distillation, and specifically discloses a distillation separation device and method for recovering tetrahydrofuran. The device comprises a distillation tower, a reboiler installed at the bottom of the distillation tower, a condenser installed at the top of the distillation tower, and a layered assembly disposed within the distillation tower. The layered assembly is arranged in multiple groups from top to bottom within the distillation tower. The layered assembly includes a tray, at least one end of which has a notch, and a gap is formed between the notch and the inner wall of the distillation tower. The present invention provides notches in the sides of the tray, so that when liquid on the upper tray reaches a certain thickness, it can overflow through the notch to the lower tray. Steam from the lower tray can be discharged upward through the steam holes, heating the liquid within the tray. A one-way plate is provided to prevent steam from rising through the notch in the tray and can only rise through the steam holes, thereby ensuring the rising pressure of the gas within the steam holes.

Description

Technical Field

[0001] The present invention relates to the technical field of tetrahydrofuran distillation, in particular to a distillation separation device and a method for recovering tetrahydrofuran. Background Art

[0002] Prior art publication CN102316949A discloses a dividing wall distillation column having a main column with a dividing wall. The main column includes a pressure equalizing unit for equalizing the pressure between a primary partition and a main partition separated by the dividing wall. Due to the uniform pressure drop between the two partitions separated by the dividing wall, the dividing wall distillation column can be operated more easily.

[0003] The boiling point of tetrahydrofuran is 66°C. Special circumstances: Under certain special circumstances, such as temperature gradients or local overheating during the distillation process, the solute may reach saturation or supersaturation in certain areas of the still and crystallize;

[0004] The problem with the distillation tower of the prior art is that, due to the need to reserve an overflow port, a portion of the steam will rise directly from the gap in the overflow port, resulting in a lower pressure of the gas coming out of the steam holes on the tower plate. Therefore, when the steam pressure is insufficient, the steam cannot rise from the steam holes on the tower plate, resulting in the inability of the steam to exchange heat with the liquid, resulting in lower distillation efficiency. Summary of the Invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0006] The present invention provides a distillation separation device and method for recovering tetrahydrofuran, which can solve the problem in the prior art that steam cannot rise when the gas pressure on the tray is insufficient. The specific solution is as follows:

[0007] A distillation separation device for recovering tetrahydrofuran comprises a distillation tower, a reboiler is installed at the bottom of the distillation tower, a condenser is installed at the top of the distillation tower, and a layered assembly is arranged inside the distillation tower. The layered assembly is arranged in multiple groups from top to bottom inside the distillation tower, and the layered assembly comprises:

[0008] a tower plate, wherein at least one end of the tower plate has a notch, and a gap is formed between the notch and the inner wall of the distillation tower;

[0009] Steam holes are provided on the tray;

[0010] A water baffle is connected to the end of the tower plate and the distillation tower having a gap, and the water baffle forms a cavity on the top of the tower plate for storing liquid;

[0011] a one-way plate connected to one end of the tower plate and the distillation tower having a gap, and hingedly connected to the bottom of the tower plate via a torsion spring;

[0012] By setting notches on the side of the tower plate, when the liquid on the upper tower plate reaches a certain thickness, it can overflow to the lower tower plate through the notches. The steam from the lower layer can be discharged upward through the steam holes to heat the liquid in the tower plate. By setting a one-way plate, the steam cannot rise from the notches of the tower plate and can only rise from the steam holes, thereby ensuring the rising air pressure of the gas in the steam holes.

[0013] Preferably, a liquid inlet is provided in the middle of the distillation tower, a liquid inlet pipe is fixedly installed in the middle of the liquid inlet, a heating circulation port is provided at the bottom and side wall of the distillation tower, the two heating circulation ports are connected by a heating circulation pipe, the reboiler is installed in the middle of the heating circulation pipe, and the bottom of the heating circulation pipe is connected to a lower discharge pipe.

[0014] Preferably, the distillation tower has a plurality of heating circulation ports on the side wall, and the plurality of heating circulation ports are at different heights on the distillation tower.

[0015] Preferably, the top and top side wall of the distillation tower are provided with condensation circulation ports, a condensation circulation pipe is connected between the two condensation circulation ports, the condenser is fixedly installed in the middle of the condensation circulation pipe, the inside of the condenser is provided with a condensation pipe, the condensation pipe is S-shaped inside the condenser, and both ends of the condensation pipe extend to the outside of the condenser, the end of the condensation pipe is connected to the cooling liquid source, and the bottom of the condensation circulation pipe is connected to the upper discharge pipe.

[0016] Preferably, the notches of two adjacent trays among the plurality of trays inside the distillation tower are staggered, so that steam at the bottom of the distillation tower can rise to the upper part of the distillation tower along the air flow path formed by the plurality of trays. There are two notches on the tray, and the two notches are symmetrically arranged at both ends of the tray. The deflection angle between two adjacent trays in the distillation tower is 90°.

[0017] By staggering several tower plates, the position of the liquid can be dispersed when the liquid overflows from the gaps in the tower plates, thereby improving the efficiency of heat exchange.

[0018] Preferably, an overflow port is provided at the top of the water baffle, and there is a gap between the edge of the one-way plate and the inner wall of the distillation tower. When the processes of liquid inflow, liquid outflow, evaporation and condensation in the distillation tower reach a balance point, the liquid overflowing from the overflow port can overcome the torsion force of the torsion spring, causing the one-way plate to rotate downward, and the limit position of the one-way plate's upward rotation is horizontal.

[0019] Preferably, the top of the steam hole on the tower plate is provided with an air jet assembly, and the air jet assembly comprises:

[0020] A cover, with a plurality of air outlets at the bottom, the bottom of the cover is fixedly connected to the top of the tower plate and corresponds to the position of the steam holes;

[0021] An upper steam pipe, the upper steam pipe is fixedly connected to the top of the steam hole, the top of the upper steam pipe is higher than the height of the overflow port, and an annular cavity is formed between the upper steam pipe and the cover;

[0022] An encryption block, wherein a plurality of fine holes are formed on the encryption block;

[0023] By setting up the encryption block, the gas density can be increased when it rises. The encryption block has several fine holes, and the inner diameter of the fine holes can be set according to actual needs;

[0024] a float valve, which is installed on the top of the upper steam pipe and can block the upper steam pipe. A spring is connected between the top of the float valve and the upper inner wall of the cover. When steam enters the steam hole, the rising pressure of the steam can overcome the pressure of the spring and push the float valve open, allowing the steam to enter the annular cavity and finally be discharged from the outlet;

[0025] By setting a float valve, when the air pressure is low, the float valve cannot be pushed open, allowing the gas to concentrate. When the air pressure accumulates to a certain value, the float valve can be pushed open, thereby ensuring the stability of the air pressure in the steam hole.

[0026] Preferably, the inner bottom of the distillation tower is connected to a support base, the middle part of the support base is rotatably connected to a drive rod, the bottom of the drive rod is connected to a spiral rod, the spiral rod extends into the heating circulation port at the bottom of the distillation tower, the top of the drive rod is connected to a blade, and the outer wall of the drive rod is connected to a scraper.

[0027] A distillation separation method for recovering tetrahydrofuran comprises the following steps:

[0028] S1. The rectified tetrahydrofuran raw material liquid is injected from the middle of the distillation tower. The raw liquid flows to the tray in the lower half of the distillation tower. When it reaches a certain capacity, the raw liquid overflows from the side of the tray to the next tray, and then the reboiler and condenser are started;

[0029] S2, the reboiler heats the liquid to 66 ℃ - 68 ℃ of tetrahydrofuran, so that the light component tetrahydrofuran in the original liquid is evaporated, and the evaporated gas enters the interior of the distillation tower;

[0030] S3. The gas rises inside the distillation tower, rising from the steam holes on the tray to the top of the tray, and passes through each tray in turn, allowing the steam to come into contact with the original liquid, exchanging heat, causing part of the steam to be liquefied and part of the original liquid to be vaporized. The gas then continues to rise until it reaches the top of the distillation tower;

[0031] S4. The condenser at the top of the distillation tower cools and liquefies the steam to obtain the final tetrahydrofuran liquid.

[0032] Preferably, a circulation pump is installed at the bottom of the reboiler for pumping the liquid in the distillation tower into the reboiler, and then injecting the heated boiling steam into the distillation tower.

[0033] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0034] 1. By arranging blades, a driving rod and a screw rod at the bottom of the distillation tower, when the liquid flows out from the heating circulation port, the screw rod is driven to rotate under the action of the water flow, thereby further driving the driving rod and blades to rotate. The rotation of the blades generates wind force, blowing the steam to the top of the distillation tower, thereby accelerating the rising speed of the steam.

[0035] 2. By setting notches on the side of the tower plate, when the liquid on the upper tower plate reaches a certain thickness, it can overflow to the lower tower plate through the notches. The steam from the lower layer can be discharged upward through the steam holes to heat the liquid in the tower plate. By setting a one-way plate, the steam cannot rise from the notch of the tower plate and can only rise from the steam holes, thereby ensuring the rising gas pressure in the steam holes.

[0036] 3. By setting a float valve, when the air pressure is low, the float valve cannot be opened, allowing the gas to concentrate. When the air pressure accumulates to a certain value, the float valve can be opened, thereby ensuring the stability of the air pressure in the steam hole.

[0037] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0039] Figure 1 It is an overall three-dimensional diagram of the present invention;

[0040] Figure 2 is a three-dimensional diagram of the distillation tower of the present invention;

[0041] Figure 3 It is a three-dimensional cross-sectional view of the present invention;

[0042] Figure 4 It is a front view of the present invention;

[0043] Figure 5 It is a front cross-sectional view of the present invention;

[0044] Figure 6 For the present invention Figure 5 Enlarged view of point A in the middle;

[0045] Figure 7 This is a structural diagram of the front part of the present invention;

[0046] Figure 8 It is a right side view of the present invention;

[0047] Figure 9 It is a left side view of the present invention;

[0048] Figure 10 This is a diagram of the tower plate structure of the present invention;

[0049] The accompanying drawings are numerals as follows:

[0050] 1. Distillation tower; 101. Liquid inlet pipe; 102. Heating circulation pipe; 103. Lower discharge pipe; 104. Condenser; 105. Condensation circulation pipe; 106. Upper discharge pipe; 107. Reboiler; 108. Liquid inlet; 109. Heating circulation port; 110. Condensation circulation port; 111. Condenser; 2. Layering assembly; 201. Tray; 202. Steam hole; 203. Water baffle; 204. Overflow port; 205. One-way plate; 206. Jet assembly; 2061. Cover; 2062. Gas outlet; 2063. Steam pipe; 2064. Annular cavity; 2065. Encryption block; 2066. Fine hole; 2067. Float valve; 2068. Spring; 207. Support seat; 208. Drive rod; 209. Blade; 210. Scraper; 211. Screw rod. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used to explain the principles of the present invention together with the embodiments of the present invention.

[0052] See Figures 1-10 Example 1: This example provides a distillation separation device for recovering tetrahydrofuran, comprising a distillation tower 1, a reboiler 107 installed at the bottom of the distillation tower 1, a condenser 104 installed at the top of the distillation tower 1, and a layered assembly 2 provided inside the distillation tower 1. The layered assembly 2 is provided in multiple groups from top to bottom inside the distillation tower 1, and the layered assembly 2 includes:

[0053] A tray 201, wherein at least one end of the tray 201 has a notch, and a gap is formed between the notch and the inner wall of the distillation tower 1;

[0054] Steam holes 202 are provided on the tray 201;

[0055] The water retaining plate 203 is connected to the end of the tower plate 201 with the gap between the tower plate 201 and the distillation tower 1. The water retaining plate 203 forms a cavity on the top of the tower plate 201 for storing liquid;

[0056] One-way plate 205, the one-way plate 205 is connected to the end of the tower plate 201 with the gap between the distillation tower 1, and the one-way plate 205 is hinged to the bottom of the tower plate 201 through a torsion spring;

[0057] By providing a notch on the side of the tower plate 201, when the liquid on the upper tower plate 201 reaches a certain thickness, it can overflow through the notch to the lower tower plate 201, and the steam from the lower layer can be discharged upward from the steam hole 202 through the steam hole 202 to heat the liquid in the tower plate 201. By providing a one-way plate 205, the steam cannot rise from the notch of the tower plate 201 and can only rise from the steam hole 202, thereby ensuring the rising gas pressure in the steam hole 202.

[0058] As an optimized embodiment, a liquid inlet 108 is opened in the middle of the distillation tower 1, and a liquid inlet pipe 101 is fixedly installed in the middle of the liquid inlet 108. A heating circulation port 109 is opened at the bottom and side wall of the distillation tower 1. The two heating circulation ports 109 are connected by a heating circulation pipe 102. The reboiler 107 is installed in the middle of the heating circulation pipe 102, and the bottom of the heating circulation pipe 102 is connected to the lower discharge pipe 103.

[0059] As an optimized embodiment, there are several heating circulation ports 109 on the side wall of the distillation tower 1 , and the heights of the several heating circulation ports 109 on the distillation tower 1 are different.

[0060] As an optimized embodiment, a condensation circulation port 110 is opened at the top and the top side wall of the distillation tower 1, a condensation circulation pipe 105 is connected between the two condensation circulation ports 110, the condenser 104 is fixedly installed in the middle of the condensation circulation pipe 105, and a condenser 111 is provided inside the condenser 104. The condenser 111 is S-shaped inside the condenser 104, and both ends of the condenser 111 extend to the outside of the condenser 104, the end of the condenser 111 is connected to the cooling liquid source, and the bottom of the condensation circulation pipe 105 is connected to the upper discharge pipe 106.

[0061] As an optimized embodiment, the notches of two adjacent trays 201 within the distillation tower 1 are staggered, allowing steam from the bottom of the distillation tower 1 to rise to the upper portion of the distillation tower 1 along the air flow path formed by the trays 201. The trays 201 have two notches, symmetrically located at either end of the tray 201. The deflection angle between two adjacent trays 201 within the distillation tower 1 is 90°.

[0062] By staggering the distribution of the plurality of trays 201, the positions of the liquid can be dispersed when the liquid overflows from the gaps in the trays 201, thereby improving the efficiency of heat exchange.

[0063] As an optimized embodiment, an overflow port 204 is provided at the top of the water baffle 203, and there is a gap between the edge of the one-way plate 205 and the inner wall of the distillation tower 1. When the process of liquid inflow, liquid outflow, evaporation and condensation in the distillation tower 1 reaches a balance point, the liquid overflowing from the overflow port 204 can overcome the torsion force of the torsion spring, causing the one-way plate 205 to rotate downward, and the limit position of the one-way plate 205 rotating upward is horizontal.

[0064] As an optimized embodiment, the top of the steam hole 202 on the tower plate 201 has an injection assembly 206, and the injection assembly 206 includes:

[0065] The cover 2061 has a plurality of air outlets 2062 at its bottom. The bottom of the cover 2061 is fixedly connected to the top of the tower plate 201 and corresponds to the position of the steam holes 202.

[0066] The upper steam pipe 2063 is fixedly connected to the top of the steam hole 202. The top of the upper steam pipe 2063 is higher than the height of the overflow port 204. An annular cavity 2064 is formed between the upper steam pipe 2063 and the cover 2061.

[0067] The encryption block 2065 is provided with a plurality of fine holes 2066;

[0068] By setting the encryption block 2065, the gas density can be increased when the gas rises. The encryption block 2065 has a plurality of fine holes, and the inner diameter of the fine holes can be set according to actual needs;

[0069] Float valve 2067 is installed on the top of steam pipe 2063 and can block steam pipe 2063. A spring 2068 is connected between the top of float valve 2067 and the upper inner wall of cover 2061. When steam enters steam hole 202, the rising pressure of the steam can overcome the pressure of spring 2068, pushing float valve 2067 open, allowing steam to enter annular cavity 2064 and finally be discharged from outlet 2062.

[0070] By setting the float valve 2067, when the air pressure is low, the float valve 2067 cannot be pushed open, allowing the gas to concentrate. When the air pressure accumulates to a certain value, the float valve 2067 can be pushed open, thereby ensuring the air pressure in the steam hole 202 is stable.

[0071] As an optimized embodiment, the inner bottom of the distillation tower 1 is connected to a support base 207, the middle part of the support base 207 is rotatably connected to a drive rod 208, the bottom of the drive rod 208 is connected to a screw rod 211, the screw rod 211 extends into the heating circulation port 109 at the bottom of the distillation tower 1, the top of the drive rod 208 is connected to a blade 209, and the outer wall of the drive rod 208 is connected to a scraper 210.

[0072] Example 2: The technical solution of this example is different from that of Example 1 in that this example provides a distillation separation method for recovering tetrahydrofuran, comprising the following steps:

[0073] S1, injecting the rectified tetrahydrofuran raw liquid from the middle of the distillation tower 1, the raw liquid flows to the tray 201 in the lower half of the distillation tower 1, and when it reaches a certain capacity, the raw liquid overflows from the side of the tray 201 to the next tray 201, and then starts the reboiler 107 and the condenser 104;

[0074] S2, reboiler 107 heats the liquid to 66℃-68℃ of tetrahydrofuran, so that the light component tetrahydrofuran in the original liquid is evaporated, and the evaporated gas enters the interior of distillation tower 1;

[0075] S3. The gas rises inside the distillation tower 1, rising from the steam holes 202 on the tray 201 to the top of the tray 201. The gas then passes through each tray 201 in sequence, allowing the steam to contact the raw liquid and exchange heat with it, causing part of the steam to be liquefied and part of the raw liquid to be vaporized. The gas then continues to rise until it reaches the top of the distillation tower 1.

[0076] S4. The condenser 104 at the top of the distillation tower 1 cools and liquefies the steam to obtain the final tetrahydrofuran liquid.

[0077] As an optimized embodiment, a circulation pump is installed at the bottom of the reboiler 107 for pumping the liquid in the distillation tower 1 into the reboiler 107 , and then injecting the heated boiling steam into the distillation tower 1 .

[0078] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0079] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A distillation separation device for recovering tetrahydrofuran, comprising a distillation tower (1), characterized in that: A reboiler (107) is installed at the bottom of the distillation tower (1), a condenser (104) is installed at the top of the distillation tower (1), and a layered assembly (2) is arranged inside the distillation tower (1). The layered assembly (2) is arranged in multiple groups from top to bottom inside the distillation tower (1), and the layered assembly (2) includes: A tower plate (201), wherein at least one end of the tower plate (201) has a notch, and a gap is formed between the notch and the inner wall of the distillation tower (1); Steam holes (202) are provided on the tower plate (201); A water baffle (203) is connected to the end of the tower plate (201) and the distillation tower (1) with a gap. The water baffle (203) forms a cavity on the top of the tower plate (201) for storing liquid. An overflow port (204) is provided on the top of the water baffle (203). A gap is provided between the edge of the one-way plate (205) and the inner wall of the distillation tower (1). When the process of liquid inflow, liquid outflow, evaporation and condensation in the distillation tower (1) reaches a balance point, the liquid overflowing from the overflow port (204) can overcome the torsion force of the torsion spring, causing the one-way plate (205) to rotate downward. The limit position of the one-way plate (205) for rotating upward is horizontal. A one-way plate (205), the one-way plate (205) is connected to the end of the tower plate (201) and the distillation tower (1) having a gap, and the one-way plate (205) is hinged to the bottom of the tower plate (201) via a torsion spring; The top of the steam hole (202) is provided with an air jet assembly (206), and the air jet assembly (206) includes: A cover (2061) has a plurality of air outlets (2062) at its bottom, and the bottom of the cover (2061) is fixedly connected to the top of the tower plate (201) and corresponds to the position of the steam holes (202); An upper steam pipe (2063), the upper steam pipe (2063) is fixedly connected to the top of the steam hole (202); the top of the upper steam pipe (2063) is higher than the overflow port (204); and an annular cavity (2064) is provided between the upper steam pipe (2063) and the cover (2061); An encryption block (2065), wherein the encryption block (2065) is provided with a plurality of fine holes (2066); The float valve (2067) is installed on the top of the steam pipe (2063) and can block the steam pipe (2063). A spring (2068) is connected between the top of the float valve (2067) and the upper inner wall of the cover (2061). When steam enters the steam hole (202), the rising pressure of the steam can overcome the pressure of the spring (2068) and push the float valve (2067) open, allowing the steam to enter the annular cavity (2064) and finally be discharged from the outlet (2062).

2. A distillation separation device for recovering tetrahydrofuran (THF) as claimed in claim 1, characterized in that: A liquid inlet (108) is provided in the middle of the distillation tower (1), a liquid inlet pipe (101) is fixedly installed in the middle of the liquid inlet (108), a heating circulation port (109) is provided at the bottom and side wall of the distillation tower (1), two heating circulation ports (109) are connected via a heating circulation pipe (102), the reboiler (107) is installed in the middle of the heating circulation pipe (102), and the bottom of the heating circulation pipe (102) is connected to a lower discharge pipe (103).

3. A distillation separation device for recovering tetrahydrofuran (THF) as claimed in claim 2, characterized in that: The distillation tower (1) has a plurality of heating circulation ports (109) on the side wall, and the plurality of heating circulation ports (109) are located at different heights on the distillation tower (1).

4. A distillation separation device for recovering tetrahydrofuran (THF) as claimed in claim 1, characterized in that: The top and the top side wall of the distillation tower (1) are provided with condensation circulation ports (110), a condensation circulation pipe (105) is connected between the two condensation circulation ports (110), the condenser (104) is fixedly installed in the middle of the condensation circulation pipe (105), the interior of the condenser (104) is provided with a condensation pipe (111), the condensation pipe (111) is S-shaped inside the condenser (104), and both ends of the condensation pipe (111) extend to the outside of the condenser (104), the end of the condensation pipe (111) is connected to a cooling liquid source, and the bottom of the condensation circulation pipe (105) is connected to an upper discharge pipe (106).

5. A distillation separation device for recovering tetrahydrofuran as claimed in claim 1, characterized in that: The notches of two adjacent plates (201) among the plurality of plates (201) inside the distillation tower (1) are staggered, so that steam at the bottom of the distillation tower (1) can rise to the upper part of the distillation tower (1) along the air flow path formed by the plurality of plates (201). There are two notches on the plate (201), and the two notches are symmetrically arranged at both ends of the plate (201). The deflection angle of two adjacent plates (201) in the distillation tower (1) is 90°.

6. A distillation separation device for recovering tetrahydrofuran as claimed in claim 1, characterized in that: The inner bottom of the distillation tower (1) is connected to a support base (207), the middle of the support base (207) is rotatably connected to a driving rod (208), the bottom of the driving rod (208) is connected to a spiral rod (211), the spiral rod (211) extends into a heating circulation port (109) at the bottom of the distillation tower (1), the top of the driving rod (208) is connected to a blade (209), and the outer wall of the driving rod (208) is connected to a scraper (210).

7. A distillation separation method for recovering tetrahydrofuran, using the distillation separation equipment for recovering tetrahydrofuran according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. The rectified tetrahydrofuran raw material liquid is injected from the middle of the distillation tower (1). The raw liquid flows to the tray (201) in the lower half of the distillation tower (1). When a certain volume is reached, the raw liquid overflows from the side of the tray (201) to the next tray (201). Then, the reboiler (107) and the condenser (104) are started. S2, the reboiler (107) heats the liquid to 66°C-68°C of tetrahydrofuran, so that the light component tetrahydrofuran in the original liquid is evaporated, and the evaporated gas enters the interior of the distillation tower (1); S3, the gas rises inside the distillation tower (1), rises from the steam holes (202) on the tower plate (201) to the top of the tower plate (201), and passes through each stage of the tower plate (201) in sequence, allowing the steam to contact with the original liquid, causing heat exchange, so that part of the steam is liquefied and part of the original liquid is vaporized, and then the gas continues to rise until it reaches the top of the distillation tower (1); S4. The condenser (104) at the top of the distillation tower (1) cools and liquefies the steam to obtain the final tetrahydrofuran liquid.

8. A rectification and separation method for recovering tetrahydrofuran (THF) as claimed in claim 7, characterized in that: A circulating pump is installed at the bottom of the reboiler (107) for pumping the liquid in the distillation tower (1) into the reboiler (107), and then injecting the heated boiling steam into the distillation tower (1).

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