Continuous recovery and distillation system and method for high-salt NMP wastewater

Abstract

The invention discloses a continuous recovery and distillation system and method for high-salt NMP wastewater, comprising a distillation tank, a heating block is fixedly installed on the outer surface of the distillation tank, a vacuum pump is fixedly installed on one side of the distillation tank, an air inlet of the vacuum pump is fixedly connected to an air suction pipe extending into the distillation tank, a stirring mechanism is arranged on the distillation tank, a steam pipe is fixedly connected to the top of the distillation tank, a first valve is fixedly installed on the steam pipe, a condenser is arranged on one side of the distillation tank, a first water inlet pipe and a water outlet pipe are respectively fixedly connected to the condenser, and the invention relates to the technical field of NMP recovery. The continuous recovery and distillation system and method for high-salt NMP wastewater solve the problems of incomplete distillation and separation of NMP and dichlorobenzene and poor distillation effect during the recovery and distillation of the existing high-salt NMP wastewater, and the problems of inconvenient automatic control of the condensation time after NMP or dichlorobenzene enters the condenser, resulting in incomplete condensation or poor distillation effect.

Description

Technical Field

[0001] The invention relates to the technical field of NMP recovery, in particular to a continuous recovery and distillation system and method for high-salt NMP wastewater. Background Art

[0002] NMP is widely used in the refining of high-grade lubricating oils, synthesis of polymers, insulating materials, pesticides, pigments, cleaning agents, etc. It is used as an absorbent for acetylene and high-grade alkynes in the natural gas to acetylene industry. It is a colorless, transparent liquid with a boiling point of 202°C and a flash point of 86.1°C. It is miscible with water and soluble in ether, acetone and various organic solvents. It has a slight ammonia smell and stable chemical properties. It is non-corrosive to carbon steel and aluminum, but slightly corrosive to copper.

[0003] In the process of NMP production, a lot of mixed products and wastewater are generated. The wastewater contains high-salt NMP and dichlorobenzene. The traditional separation method is to distill NMP and dichlorobenzene according to their different boiling points.

[0004] The prior art has the following defects and deficiencies:

[0005] 1. During the distillation of NMP and dichlorobenzene, NMP and dichlorobenzene are condensed through condensers respectively according to their different boiling points and then collected in a material box. However, NMP and dichlorobenzene are separated after distillation using the same channel during the condensation process. During the dichlorobenzene distillation recovery process, dichlorobenzene will remain on the inner wall of the condenser. When NMP is distilled and recovered after the dichlorobenzene distillation recovery is completed, dichlorobenzene will enter the material box together with NMP, resulting in incomplete distillation separation of NMP and dichlorobenzene, and poor distillation effect.

[0006] 2. During the distillation of NMP and dichlorobenzene, NMP and dichlorobenzene are condensed through condensers according to their different boiling points and then collected in a material box. However, the condensation time of NMP or dichlorobenzene after entering the condenser is not easy to control. If the time is too short, it is easy to cause incomplete condensation and liquefaction of NMP or dichlorobenzene, resulting in poor distillation effect. If the time is too long, the distillation efficiency is reduced, which is not easy to be automatically controlled. Summary of the invention

[0007] 1. Technical issues to be solved

[0008] In view of the deficiencies in the prior art, the present invention provides a continuous recovery and distillation system and method for high-salt NMP wastewater, which solves the problems of incomplete separation of NMP and dichlorobenzene and poor distillation effect during the recovery and distillation of the existing high-salt NMP wastewater, and the problem that the condensation time of NMP or dichlorobenzene after entering the condenser is not convenient for automatic control, resulting in incomplete condensation or poor distillation effect.

[0009] (II) Technical solution

[0010] To achieve the above object, the present invention is realized by the following technical solutions: a continuous recovery rectification system for high-salt NMP wastewater, including a rectification tank, a heating block is fixedly installed on the outer surface of the rectification tank, a vacuum pump is fixedly installed on one side of the rectification tank, an air suction pipe extending into the rectification tank is fixedly connected to the air inlet of the vacuum pump, a stirring mechanism is arranged on the rectification tank, a steam pipe is fixedly connected to the top of the rectification tank, a first valve is fixedly installed on the steam pipe, a condensation box is arranged on one side of the rectification tank, a first water inlet pipe and a first water outlet pipe are respectively fixedly connected to the condensation box, a condensation pipe is fixedly installed inside the condensation box, a waste discharge pipe is fixedly installed at the bottom of the condensation pipe, a second valve is fixedly installed on the waste discharge pipe, the steam pipe is communicated with the condensation pipe, and an air intake control component is fixedly installed on the steam pipe, a scraping mechanism is arranged inside the condensation pipe, the scraping mechanism includes an electric push rod, the electric push rod penetrates through the shell of the condensation box and is sealed with the shell through a sealing ring at the connection, one end of the electric push rod is fixedly connected with a piston scraper, a first cleaning component is arranged on the piston scraper, a second cleaning component is arranged on the condensation box, the bottom of the condensation pipe is fixedly connected with a first liquid outlet pipe and a second liquid outlet pipe through a connecting pipe, a third valve is fixedly installed on the first liquid outlet pipe, a first material box is fixedly installed at the bottom end of the first liquid outlet pipe, a fourth valve is fixedly installed on the second liquid outlet pipe, a second material box is fixedly installed at the bottom end of the second liquid outlet pipe, and a drying mechanism and a cleaning mechanism are fixedly installed on the condensation pipe.

[0011] Preferably, a liquid inlet pipe is fixedly installed at the bottom of the rectification tank, a temperature controller is fixedly installed inside the rectification tank, and a pressure gauge is fixedly installed on the rectification tank.

[0012] Preferably, the stirring mechanism includes a stirring motor, a stirring shaft and stirring paddles, the stirring motor is fixedly installed on the rectification tank, the stirring shaft is fixedly installed at the output end of the stirring motor and extends into the rectification tank, and stirring paddles are fixedly installed at the end of the stirring shaft.

[0013] Preferably, the air intake control component includes an air intake cylinder, the air intake cylinder penetrates through a through groove opened at the top of the U-shaped plate and is slidably connected with the U-shaped plate, the gap between the air intake cylinder and the through groove is sealed through a sealing ring, the top end of the air intake cylinder is communicated with the steam pipe and the bottom is open, first sliding grooves are opened on the inner walls of both sides of the steam pipe, sliders are slidably connected inside the first sliding grooves, a first spring is fixedly connected between the top end of the slider and the first sliding groove, a U-shaped plate is fixedly connected to one side of the slider, a support rod is fixedly connected to the bottom of the U-shaped plate, and a plug that is movably clamped with the bottom opening of the air intake cylinder is fixedly connected to the top of the support rod.

[0014] Preferably, the first cleaning component is symmetrically distributed on both sides of the piston scraper, and the first cleaning component includes a second slide groove distributed at an equal angle on the surface of the piston scraper, a first arc-shaped scraper is arranged on the second slide groove, the bottom of the first arc-shaped scraper is fixedly connected to a block that is slidably engaged with the second slide groove, a sleeve is arranged on one side of the first arc-shaped scraper, a connecting rod is arranged between the sleeve and the first arc-shaped scraper, and both ends of the connecting rod are respectively hinged to the first arc-shaped scraper and the sleeve, and the sleeve close to the electric push rod is movably mounted on the electric push rod.

[0015] Preferably, the second cleaning assembly comprises a sleeve, a second spring is fixedly mounted on the inner wall of the sleeve at an equal angle, and a second arc-shaped scraper is fixedly connected to one end of the second spring.

[0016] Preferably, the air-drying mechanism includes an air compressor, an air blowing pipe and an air nozzle. The air compressor is fixedly mounted on the condensation box. One end of the air blowing pipe is connected to the air outlet of the air compressor, and the other end is connected to the air nozzle. The air nozzle is fixedly mounted on the top wall inside the first water outlet pipe.

[0017] Preferably, the cleaning mechanism includes a water tank, a water pump, a second water inlet pipe, a second water outlet pipe and a water spray head, the water tank is connected to the first water outlet pipe, one end of the second water inlet pipe extends to the inside of the water tank, and the other end is fixedly installed at the water inlet of the water pump, one end of the second water outlet pipe is fixedly installed at the water outlet of the water pump, and the other end is connected to the water spray head, and the water spray head is fixedly installed on the inner wall of the condenser.

[0018] The present invention also discloses a recovery and distillation method of a continuous recovery and distillation system for high-salt NMP wastewater, which specifically comprises the following steps:

[0019] S1, dichlorobenzene distillation recovery: When treating wastewater, high-salt NMP wastewater is put into a distillation tank, heated to 180°C under normal pressure, dichlorobenzene is volatilized into steam, the first valve is opened, the steam enters the condenser through the steam pipe and is condensed into liquid by the cooling water inside the condenser box, the fourth valve on the second liquid outlet pipe connected to the second material box is closed, and then the dichlorobenzene liquid flows to the first material box through the first liquid outlet pipe for recovery;

[0020] S2, NMP distillation recovery: After the distillation tank is heated at 180°C until no steam is generated, the third valve on the first liquid outlet pipe connected to the first material box is closed, and the vacuum pump is started to evacuate the inside of the distillation tank to 5KP. At this time, the temperature of the distillation tank body reaches 180°C. At this time, the air pressure is low, which reduces the boiling point of NMP. The residual heat of the distillation tank shell can make NMP boil and generate NMP steam. At the same time, when the temperature drops below 130°C, the heating block is started again for heating. When the steam reaches a certain amount, the first valve and the fourth valve on the second liquid outlet pipe connected to the second material box are opened, and the third valve is closed. The NMP steam is condensed into liquid through the first water outlet pipe and flows to the inside of the second material box for recovery.

[0021] Preferably, when the internal pressure of the distillation tank reaches normal pressure, the first valve is closed and the operation is repeated until the NMP is completely evaporated.

[0022] Beneficial Effects

[0023] The present invention provides a continuous recovery and distillation system and method for high-salt NMP wastewater, which has the following beneficial effects compared with the prior art:

[0024] (1) The continuous recovery and distillation system and method of high-salt NMP wastewater is characterized in that an electric push rod and a piston scraper are arranged inside the condenser. After the dichlorobenzene distillation is completed, part of the dichlorobenzene will remain on the inner wall of the condenser. The bottom of the condenser is fixedly connected to a waste discharge pipe, and the piston scraper is driven by the electric push rod to move back and forth inside the condenser to scrape off the residual dichlorobenzene on the inner wall of the condenser. In addition, a second cleaning component is fixedly installed in the first water inlet pipe, and the second cleaning component is sleeved on the electric push rod. When the electric push rod moves back and forth, the dichlorobenzene on the surface of the electric push rod is scraped off by the second arc-shaped scraper. In addition, the first cleaning components are respectively arranged on both sides of the piston scraper, one of which is A sliding sleeve is arranged on the electric push rod, and the sliding sleeve is connected to the first arc scraper through a connecting rod. The first arc scraper can slide on the second sliding groove on the surface of the piston scraper through a block, and then when the piston scraper moves to the far right, the sliding sleeve and the second cleaning component are pressed tightly to drive the first arc scraper to move on the surface of the piston scraper and then scrape off the dichlorobenzene on one side of the piston scraper. At the same time, when the piston scraper moves to the far left, the sliding sleeve and the inner wall of the condenser are squeezed to drive the first arc scraper to move on the surface of the piston scraper and then scrape off the dichlorobenzene on the other side of the piston scraper. Then the dichlorobenzene scraped off the inner wall of the condenser and the electric push rod and the surface of the piston scraper is discharged outward through the waste pipe.

[0025] (2) The continuous recovery and distillation system and method of high-salt NMP wastewater are provided with an air-drying mechanism and a cleaning mechanism on the condenser tube. The cleaning mechanism includes a water tank, which is connected to the first water outlet pipe and can recover the condensed water in the condenser tube. When scraping dichlorobenzene inside the condenser tube, the water inside the water tank can be sprayed into the condenser tube through the second water outlet pipe and the water spray head by starting the water pump, so as to achieve the purpose of flushing, so that the dichlorobenzene scraped from the inside of the condenser tube is quickly discharged from the waste pipe under the impact of the water flow. At the same time, the air compressor is started, and the air flow is blown into the inside of the condenser tube by the air nozzle. The electric push rod, the piston scraper and the inner wall of the condenser tube are air-dried by the air flow, and the residual dichlorobenzene is further removed. Then, when distilling and recovering NMP, the cleanliness of the inside of the condenser tube is guaranteed, so that dichlorobenzene will not be mixed into NMP, and the purpose of thorough separation is achieved. At the same time, the purpose of condensed water recovery is achieved, so that water resources are recycled.

[0026] (3) The continuous recovery and distillation system and method of high-salt NMP wastewater is provided by installing an air intake control component in the steam pipe. The air intake control component includes an air intake cylinder. A first slide groove is provided on the inner wall of the steam pipe. A slider is slidably connected inside the first slide groove. The top of the slider is fixedly connected to a first spring. One side of the slider is fixedly connected to a shaped plate and a connecting rod. Steam enters the air intake cylinder from the steam pipe, enters the steam pipe through the bottom opening of the air intake cylinder, and then reaches the inside of the condenser. A plug is fixedly installed on the top of the connecting rod. When the air intake inside the condenser is too large, the internal pressure increases, and the condenser will automatically The connecting rod is automatically pushed upward, and the bottom opening of the air inlet cylinder is blocked by the plug on the top of the connecting rod, temporarily blocking the entry of steam, thereby avoiding the problem that the steam intake is too large, resulting in the steam staying too short inside the condenser, resulting in incomplete condensation and poor distillation effect. When the steam inside the condenser is condensed and the pressure decreases, the connecting rod is automatically reset under the action of the elastic force of the first spring, and the steam continues to enter the steam pipe from the air inlet cylinder, so as to achieve the purpose of dynamically controlling the air intake amount. No manual control is required, which saves time and effort. At the same time, it can ensure that the steam is fully condensed inside the condenser, thereby improving the distillation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the external three-dimensional structure of the present invention;

[0028] Figure 2 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 3 For the present invention Figure 2 The enlarged structural diagram at A in the middle;

[0030] Figure 4 For the present invention Figure 2 The enlarged structural diagram at B in the middle;

[0031] Figure 5 For the present invention Figure 2Schematic diagram of the enlarged structure at position C

[0032] Figure 6 Schematic diagram of the overall structure of the first cleaning component of the present invention

[0033] Figure 7 Schematic diagram of the overall structure of the first cleaning component of the present invention

[0034] Figure 8 Schematic diagram of the overall structure of the second cleaning component of the present invention

[0035] Fig. 9 Schematic diagram of the partial structure of the present invention

[0036] Fig.10 Schematic diagram of the partial structure of the present invention

[0037] Fig.11 Process flow chart of the recovery rectification method of the present invention

[0038] In the figure, 1, rectification tank; 1001, liquid inlet pipe; 1002, temperature controller; 1003, air pressure gauge; 2, vacuum pump; 21, suction pipe; 3, stirring mechanism; 31, stirring motor; 32, stirring shaft; 33, stirring paddle; 4, steam pipe; 41, first valve; 5, condensation box; 51, first water inlet pipe; 52, first water outlet pipe; 53, condensation pipe; 54, sealing ring; 6, air intake control component; 61, air intake cylinder; 62, first chute; 63, slider; 64, first spring; 65, U-shaped plate; 66, support rod; 67, plug; 7, scraping mechanism; 71, electric push rod; 72, piston scraper; 73, waste discharge pipe; 731, second valve; 74, first liquid outlet pipe; 741, third valve; 75, first material box; 76, second liquid outlet pipe; 761, fourth valve; 77, second material box; 8, first cleaning component; 81, second chute; 82, first arc-shaped scraper; 83, clamping block; 84, sliding sleeve; 85, connecting rod; 9, second cleaning component; 91, sleeve; 92, second spring; 93, second arc-shaped scraper; 10, air drying mechanism; 101, air compressor; 102, air blowing pipe; 103, air jet nozzle; 11, cleaning mechanism; 111, water tank; 112, water pump; 113, second water inlet pipe; 114, second water outlet pipe; 115, water spray head. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] See also Figure 1-11 , the embodiment of the present invention provides two technical solutions:

[0041] Embodiment 1:

[0042] The continuous recovery and distillation system of high-salt NMP wastewater comprises a distillation tank 1, a heating block is fixedly installed on the outer surface of the distillation tank 1, a vacuum pump 2 is fixedly installed on one side of the distillation tank 1, an air inlet of the vacuum pump 2 is fixedly connected to an air suction pipe 21 extending to the inside of the distillation tank 1, a stirring mechanism 3 is arranged on the distillation tank 1, a steam pipe 4 is fixedly connected to the top of the distillation tank 1, a first valve 41 is fixedly installed on the steam pipe 4, a condensation box 5 is arranged on one side of the distillation tank 1, a first water inlet pipe 51 and a first water outlet pipe 52 are respectively fixedly connected to the condensation box 5, a condensation pipe 53 is fixedly installed inside the condensation box 5, a waste discharge pipe 73 is fixedly installed at the bottom of the condensation pipe 53, a second valve 731 is fixedly installed on the waste discharge pipe 73, the steam pipe 4 is connected to the condensation pipe 53, and an air intake control component 6 is fixedly installed on the steam pipe 4 A scraper mechanism 7 is arranged inside the condenser 53, and the scraper mechanism 7 includes an electric push rod 71, and the electric push rod 71 passes through the shell of the condenser box 5 and is sealed with the shell by a sealing ring 54. A piston scraper 72 is fixedly connected to one end of the electric push rod 71, and a first cleaning component 8 is arranged on the piston scraper 72. A second cleaning component 9 is arranged on the condenser box 5. A first liquid outlet pipe 74 and a second liquid outlet pipe 76 are fixedly connected to the bottom of the condenser 53 through a connecting pipe. A 742 and a third valve 741 are fixedly installed on the first liquid outlet pipe 74, a first material box 75 is fixedly installed on the bottom end of the first liquid outlet pipe 74, a fourth valve 761 is fixedly installed on the second liquid outlet pipe 76, and a second material box 77 is fixedly installed on the bottom end of the second liquid outlet pipe 76. An air drying mechanism 10 and a cleaning mechanism 11 are fixedly installed on the condenser 53.

[0043] Embodiment 2:

[0044] The continuous recovery and distillation system of high-salt NMP wastewater comprises a distillation tank 1, a heating block is fixedly installed on the outer surface of the distillation tank 1, a vacuum pump 2 is fixedly installed on one side of the distillation tank 1, an air inlet of the vacuum pump 2 is fixedly connected to an air suction pipe 21 extending to the inside of the distillation tank 1, a stirring mechanism 3 is arranged on the distillation tank 1, a steam pipe 4 is fixedly connected to the top of the distillation tank 1, a first valve 41 is fixedly installed on the steam pipe 4, a condensation box 5 is arranged on one side of the distillation tank 1, a first water inlet pipe 51 and a first water outlet pipe 52 are respectively fixedly connected to the condensation box 5, a condensation pipe 53 is fixedly installed inside the condensation box 5, a waste discharge pipe 73 is fixedly installed at the bottom of the condensation pipe 53, a second valve 731 is fixedly installed on the waste discharge pipe 73, the steam pipe 4 is connected to the condensation pipe 53, and an air intake control component 6 is fixedly installed on the steam pipe 4 A scraper mechanism 7 is arranged inside the condenser 53, and the scraper mechanism 7 includes an electric push rod 71, and the electric push rod 71 passes through the shell of the condenser box 5 and is sealed with the shell by a sealing ring 54. A piston scraper 72 is fixedly connected to one end of the electric push rod 71, and a first cleaning component 8 is arranged on the piston scraper 72. A second cleaning component 9 is arranged on the condenser box 5. A first liquid outlet pipe 74 and a second liquid outlet pipe 76 are fixedly connected to the bottom of the condenser 53 through a connecting pipe. A 742 and a third valve 741 are fixedly installed on the first liquid outlet pipe 74, a first material box 75 is fixedly installed on the bottom end of the first liquid outlet pipe 74, a fourth valve 761 is fixedly installed on the second liquid outlet pipe 76, and a second material box 77 is fixedly installed on the bottom end of the second liquid outlet pipe 76. An air drying mechanism 10 and a cleaning mechanism 11 are fixedly installed on the condenser 53.

[0045] In the embodiment of the present invention, a liquid inlet pipe 1001 is fixedly installed at the bottom of the distillation tank 1, a temperature controller 1002 is fixedly installed in the distillation tank 1, and an air pressure gauge 1003 is fixedly installed on the distillation tank 1. The liquid inlet pipe 1001 is convenient for feeding and discharging wastewater into the distillation tank 1, the temperature controller 1002 is convenient for monitoring the temperature of the distillation tank 1 during distillation, and the air pressure gauge 1003 is convenient for monitoring the air pressure of the distillation tank 1 during distillation;

[0046] In the embodiment of the present invention, the stirring mechanism 3 includes a stirring motor 31, a stirring shaft 32 and a stirring paddle 33. The stirring motor 31 is fixedly mounted on the distillation tank 1. The stirring shaft 32 is fixedly mounted on the output end of the stirring motor 31 and extends into the distillation tank 1. The end of the stirring shaft 32 is fixedly mounted with a stirring paddle 33. The stirring motor 31 is started to drive the stirring shaft 32 to rotate and drive the stirring paddle 33 to rotate inside the distillation tank 1. During the heating process of the wastewater inside the distillation tank 1, the wastewater inside the distillation tank 1 is stirred, so that the heating is more sufficient and uniform, and the distillation effect is improved.

[0047] In an embodiment of the present invention, the air intake control assembly 6 includes an air intake cylinder 61. The air intake cylinder 61 passes through a through groove formed at the top of the C-shaped plate 65 and is slidably connected to the C-shaped plate 65. The gap between the air intake cylinder 61 and the through groove is sealed by a sealing ring. The top end of the air intake cylinder 61 is communicated with the steam pipe 4 and the bottom is open. First sliding grooves 62 are formed on the inner walls on both sides of the steam pipe 4. A slider 63 is slidably connected inside the first sliding grooves 62. A first spring 64 is fixedly connected between the top end of the slider 63 and the first sliding grooves 62. One side of the slider 63 is fixedly connected to a C-shaped plate 65. A support rod 66 is fixedly connected to the bottom of the C-shaped plate 65. A plug 67 that is movably clamped to the bottom opening of the air intake cylinder 61 is fixedly connected to the top of the support rod 66. Steam enters the inside of the air intake cylinder 61 from the steam pipe 4, enters the inside of the steam pipe 4 through the bottom opening of the air intake cylinder 61, and then reaches the inside of the condensation pipe 53. By fixedly installing the plug 67 at the top of the support rod 66, when the air intake volume inside the condensation pipe 53 is too large, the internal pressure increases, which will automatically push the support rod 66 upward, and then block the bottom opening of the air intake cylinder 61 through the plug 67 at the top of the support rod 66, temporarily blocking the entry of steam, thereby avoiding the problem that the steam stays in the condensation pipe 53 for too short a time due to excessive steam intake volume, resulting in incomplete condensation and poor rectification effect. When the pressure inside the condensation pipe 53 decreases after the steam condenses, the support rod 66 automatically resets under the elastic force of the first spring 64, and the steam continues to enter the inside of the steam pipe 4 from the air intake cylinder 61, achieving the purpose of dynamically controlling the air intake volume;

[0048] In an embodiment of the present invention, the first cleaning assembly 8 is symmetrically distributed on both sides of the piston scraper 72. The first cleaning assembly 8 includes second sliding grooves 81 that are circumferentially distributed at equal angles on the surface of the piston scraper 72. A first arc-shaped scraper 82 is arranged on the second sliding grooves 81. A block 83 that is slidably clamped to the second sliding grooves 81 is fixedly connected to the bottom of the first arc-shaped scraper 82. A sliding sleeve 84 is arranged on one side of the first arc-shaped scraper 82. A connecting rod 85 is arranged between the sliding sleeve 84 and the first arc-shaped scraper 82. Both ends of the connecting rod 85 are hinged to the first arc-shaped scraper 82 and the sliding sleeve 84 respectively. The sliding sleeve 84 close to the side of the electric push rod 71 is movably sleeved on the electric push rod 71. The sliding sleeve 84 is connected to the first arc-shaped scraper 82 through the connecting rod 85. The first arc-shaped scraper 82 is slidably connected to the second sliding grooves 81 on the surface of the piston scraper 72 through the block 83. Then, when the piston scraper 72 moves to the rightmost side, the sliding sleeve 84 is pressed against the second cleaning assembly 9, driving the first arc-shaped scraper 82 to move on the surface of the piston scraper 72 to scrape the dichlorobenzene on one side surface of the piston scraper 72. At the same time, when the piston scraper 72 moves to the leftmost side, the sliding sleeve 84 is pressed against the inner wall of the condensation pipe 53 to drive the first arc-shaped scraper 82 to move on the surface of the piston scraper 72 to scrape the dichlorobenzene on the other side surface of the piston scraper 72. Then, the dichlorobenzene scraped from the inner wall of the condensation pipe 53 and the surfaces of the electric push rod 71 and the piston scraper 72 is discharged outward through the waste discharge pipe 73;

[0049] In the embodiment of the present invention, the second cleaning assembly 9 includes a sleeve 91, and a second spring 92 is fixedly installed on the inner wall of the sleeve 91 at an equal angle. A second arc scraper 93 is fixedly connected to one end of the second spring 92. The second arc scraper 93 is sleeved on the electric push rod 71. When the electric push rod 71 moves inside the sleeve 91, the dichlorobenzene remaining on the surface of the electric push rod 71 can be scraped off by the second arc scraper 93;

[0050] In the embodiment of the present invention, the air drying mechanism 10 includes an air compressor 101, an air blowing pipe 102 and an air nozzle 103. The air compressor 101 is fixedly installed on the condensation box 5. One end of the air blowing pipe 102 is connected to the air outlet of the air compressor 101, and the other end is connected to the air nozzle 103. The air nozzle 103 is fixedly installed on the top wall inside the first water outlet pipe 52. The cleaning mechanism 11 includes a water tank 111, a water pump 112, a second water inlet pipe 113, a second water outlet pipe 114 and a water spray head 115. The water tank 111 is connected to the first water outlet pipe 52. One end of the second water inlet pipe 113 extends to the inside of the water tank 111, and the other end is fixedly installed on the water inlet of the water pump 112. One end of the second water outlet pipe 114 is fixedly installed at the water outlet of the water pump 112, and the other end is connected to the water spray head 115. The water spray head 115 is fixedly installed on the condensation pipe 53. The inner wall of the water tank 111 is connected to the first water outlet pipe 52, so that the condensed water in the condenser tank 5 can be recovered. When the dichlorobenzene in the condenser tube 53 is scraped off, the water in the water tank 111 can be sprayed into the condenser tube 53 through the second water outlet pipe 114 and the water spray head 115 by starting the water pump 112, so as to achieve the purpose of flushing, so that the dichlorobenzene scraped off from the inside of the condenser tube 53 is quickly discharged from the waste pipe 73 under the impact of the water flow, and at the same time, the air compressor 101 is started, and the air flow is blown into the condenser tube 53 by the air nozzle 103, and the electric push rod 71, the piston scraper 72 and the inner wall of the condenser tube 53 are dried by the air flow, so that the residual dichlorobenzene is further removed, and then the cleanliness of the inside of the condenser tube 53 is guaranteed when the NMP is distilled and recovered, so that dichlorobenzene will not be mixed into the NMP, and the purpose of complete separation is achieved.

[0051] The continuous recovery and distillation system of high-salt NMP wastewater has the following recovery and distillation method: the high-salt NMP wastewater is discharged into the distillation tank 1 through the liquid inlet pipe 1001, the high-salt NMP wastewater is put into the distillation tank 1, heated to 180°C under normal pressure, dichlorobenzene is volatilized into steam, the first valve 41 is opened, the steam enters the condenser 53 through the steam pipe 4, the condensed water enters the condenser box 5 through the first water inlet pipe 51 and is discharged outward through the first water outlet pipe 52, and then the steam enters the condenser box 53 and is condensed into liquid by the cooling water in the condenser box 5, and the second valve 41 connected to the second material box 77 is closed. The fourth valve 761 on the liquid outlet pipe 76 and the second valve 731 on the waste pipe 73, then the dichlorobenzene liquid flows through the first liquid outlet pipe 74 to the first material box 75 for recovery, and after the rectification tank 1 is heated to 180°C until no steam is generated, 742 is closed, the second valve 731 is opened, and the electric push rod 71 is started to push the piston scraper 72 to move back and forth inside the condenser 53 to scrape the dichlorobenzene on the inner wall of the condenser 53, and the water pump 112 is started at the same time. Starting the water pump 112 can spray the water inside the water tank 111 through the second water outlet pipe 114 and the water spray head 115 to the inside of the condenser 53, thereby achieving The purpose of flushing is to make the dichlorobenzene scraped off from the inside of the condenser 53 be quickly discharged from the waste pipe 73 under the impact of the water flow. At the same time, the air compressor 101 is started, and the air flow is blown into the inside of the condenser 53 by the air nozzle 103. The electric push rod 71, the piston scraper 72 and the inner wall of the condenser 53 are air-dried by the air flow, and the residual dichlorobenzene is further removed. The removed dichlorobenzene is discharged to the outside through the waste pipe 73. Then, the third valve 741 on the first liquid outlet pipe 74 connected to the first material box 75 is closed, and the vacuum pump 2 is started to evacuate the inside of the distillation tank 1 to 5KP. At this time, the tank body temperature of the distillation tank 1 reaches 180°C. The low air pressure reduces the boiling point of NMP. The residual heat of the shell of the distillation tank 1 can be used to make NMP boil and generate NMP vapor. At the same time, when the temperature drops below 130° C., the heating block is started again for heating. When the steam reaches a certain amount, the first valve 41 and the fourth valve 761 on the second liquid outlet pipe 76 connected to the second material box 77 are opened, and the third valve 741 is closed. The NMP vapor is condensed into liquid through the first water outlet pipe 52 and flows into the second material box 77 for recovery. When the air pressure inside the distillation tank 1 reaches the normal air pressure, the first valve 41 is closed, and the operation is repeated until the NMP is completely evaporated.

[0052] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A continuous recovery and distillation system for high-salt NMP wastewater, comprising a distillation tank (1), characterized in that: A heating block is fixedly mounted on the outer surface of the distillation tank (1); a vacuum pump (2) is fixedly mounted on one side of the distillation tank (1); an air inlet of the vacuum pump (2) is fixedly connected to an air intake pipe (21) extending into the interior of the distillation tank (1); a stirring mechanism (3) is provided on the distillation tank (1); a steam pipe (4) is fixedly connected to the top of the distillation tank (1); a first valve (41) is fixedly mounted on the steam pipe (4); a condenser (5) is provided on one side of the distillation tank (1); a first water inlet pipe (51) and a first water outlet pipe (52) are respectively fixedly connected to the condenser (5); a condenser pipe (53) is fixedly mounted inside the condenser (5); A waste pipe (73) is fixedly mounted at the bottom of the condenser (53), and a second valve (731) is fixedly mounted on the waste pipe (73). The steam pipe (4) is in communication with the condenser (53), and an air intake control assembly (6) is fixedly mounted on the steam pipe (4). A scraper mechanism (7) is arranged inside the condenser (53), and the scraper mechanism (7) comprises an electric push rod (71), and the electric push rod (71) passes through the shell of the condenser box (5) and is sealed at the connection with the shell by a sealing ring (54). One end of the electric push rod (71) is fixedly connected to a piston scraper (72), and a first cleaning assembly (8) is arranged on the piston scraper (72). The condenser box (5) A second cleaning assembly (9) is arranged on the condenser (53); the bottom of the condenser (53) is fixedly connected to a first liquid outlet pipe (74) and a second liquid outlet pipe (76) via a connecting pipe; a third valve (741) is fixedly installed on the first liquid outlet pipe (74); a first material box (75) is fixedly installed on the bottom end of the first liquid outlet pipe (74); a fourth valve (761) is fixedly installed on the second liquid outlet pipe (76); a second material box (77) is fixedly installed on the bottom end of the second liquid outlet pipe (76); and an air drying mechanism (10) and a cleaning mechanism (11) are fixedly installed on the condenser (53); the first cleaning assemblies (8) are symmetrically distributed on both sides of the piston scraper (72); The first cleaning assembly (8) comprises a second slide groove (81) which is equiangularly distributed on the surface of the piston scraper (72); a first arc-shaped scraper (82) is arranged on the second slide groove (81); the bottom of the first arc-shaped scraper (82) is fixedly connected to a clamping block (83) which is slidably engaged with the second slide groove (81); a sliding sleeve (84) is arranged on one side of the first arc-shaped scraper (82); a connecting rod (85) is arranged between the sliding sleeve (84) and the first arc-shaped scraper (82); two ends of the connecting rod (85) are respectively hinged to the first arc-shaped scraper (82) and the sliding sleeve (84); the sliding sleeve (84) on the side close to the electric push rod (71) is movably sleeved on the electric push rod (71); The second cleaning assembly (9) comprises a sleeve (91), a second spring (92) being fixedly mounted on the inner wall of the sleeve (91) at an equal angle, and a second arc-shaped scraper (93) being fixedly connected to one end of the second spring (92); The air drying mechanism (10) includes an air compressor (101), a blow pipe (102) and a jet nozzle (103). The air compressor (101) is fixedly installed on the condensation box (5). One end of the blow pipe (102) is connected to the air outlet of the air compressor (101), and the other end is connected to the jet nozzle (103). The jet nozzle (103) is fixedly installed on the inner top wall of the first water outlet pipe (52). The cleaning mechanism (11) includes a water tank (111), a water pump (112), a second water inlet pipe (113), a second water outlet pipe (114) and a water spray head (115). The water tank (111) is communicated with the first water outlet pipe (52). One end of the second water inlet pipe (113) extends into the water tank (111), and the other end is fixedly installed at the water inlet of the water pump (112). One end of the second water outlet pipe (114) is fixedly installed at the water outlet of the water pump (112), and the other end is communicated with the water spray head (115). The water spray head (115) is fixedly installed on the inner wall of the condensation pipe (53).

2. The continuous recovery and distillation system for high-salt NMP wastewater according to claim 1, characterized in that: A liquid inlet pipe (1001) is fixedly installed at the bottom of the rectification tank (1). A temperature controller (1002) is fixedly installed in the rectification tank (1). An air pressure gauge (1003) is fixedly installed on the rectification tank (1).

3. The continuous recovery and distillation system for high-salt NMP wastewater according to claim 2, characterized in that: The stirring mechanism (3) includes a stirring motor (31), a stirring shaft (32) and stirring paddles (33). The stirring motor (31) is fixedly installed on the rectification tank (1). The stirring shaft (32) is fixedly installed at the output end of the stirring motor (31) and extends into the rectification tank (1). Stirring paddles (33) are fixedly installed at the end of the stirring shaft (32).

4. The continuous recovery and distillation system for high-salt NMP wastewater according to claim 3, characterized in that: The air intake control component (6) includes an air intake cylinder (61). The air intake cylinder (61) passes through a through groove opened at the top of the U-shaped plate (65) and is slidably connected to the U-shaped plate (65). The gap between the air intake cylinder (61) and the through groove is sealed by a sealing ring. The top end of the air intake cylinder (61) is communicated with the steam pipe (4) and the bottom is open. First sliding grooves (62) are formed on the inner walls of both sides of the steam pipe (4). Sliders (63) are slidably connected inside the first sliding grooves (62). A first spring (64) is fixedly connected between the top end of the slider (63) and the first sliding groove (62). One side of the slider (63) is fixedly connected to a U-shaped plate (65). A support rod (66) is fixedly connected to the bottom of the U-shaped plate (65). A plug (67) that is movably clamped to the bottom opening of the air intake cylinder (61) is fixedly connected to the top of the support rod (66).

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