A packed tower distillation system based on two-stage distributor and its distillation process

Abstract

The invention belongs to the technical field of distillation equipment, and particularly relates to a packed tower distillation system based on a two-stage distributor and a distillation process thereof, comprising a packed tower, an evaporator, a condenser and a storage tank, wherein a two-stage distributor and a two-stage redistributor are arranged in the packed tower, a first gas outlet and a reflux port are arranged at the top of the tower, a first gas inlet and a first liquid outlet are arranged at the bottom of the tower, a liquid return port and a second gas outlet are arranged at the evaporator, a second gas inlet and a second liquid outlet are arranged at the condenser, and a liquid inlet is arranged at the storage tank; wherein valves are arranged between the second liquid outlet and the reflux port and between the second liquid outlet and the liquid inlet, and a sampling valve is arranged between the second liquid outlet and the liquid inlet, and by adopting the two-stage distributor and the two-stage redistributor, it is convenient to adjust the distributor and the redistributor to open a single stage or two stages according to the reflux amount, so as to avoid overflow due to excessive reflux amount and uneven liquid distribution, and the operation flexibility is large and the stability is good.

Description

Technical Field

[0001] The invention belongs to the technical field of distillation equipment, and in particular relates to a packed tower distillation system based on a two-stage distributor and a distillation process thereof. Background Art

[0002] The distributor is also called liquid distributor, which is mainly installed at the top of the packed tower. Its function is to evenly distribute the liquid on the cross section of the tower. It is an extremely important internal part in the packed tower. It not only affects the mass transfer efficiency of the packing, but also affects the operating elasticity of the packing. In order to avoid the deviation of the liquid in the packing layer in the packed tower, a distributor, that is, a redistributor, is usually set in the middle section of the packed tower.

[0003] However, when the packed tower is performing feeding operation, especially for intermittent distillation towers, the evaporation amount and reflux amount vary greatly at different stages, and sometimes the materials are changed. This leads to very high requirements on the operational flexibility and stability of the distributor and redistributor in the tower. Therefore, the distributor and redistributor play a vital role in the entire distillation system.

[0004] For example, Chinese patent application No. (CN201420516152.2) discloses a distillation tower with a distributor, including a packed distillation tower body, and the top of the packed distillation tower body is connected to a condensation tower, and the bottom of the packed distillation tower body is connected to a kettle, and the packed distillation tower is connected to the condensation tower and the kettle, and the packed distillation tower is provided with a first packing section and a second packing section inside the packed distillation tower body, and the first packing section is arranged above the second packing section, and also includes a liquid tank, and also includes a liquid separation device, and the liquid separation device is connected to a product tank through a first liquid outlet pipe, and also includes a distributor. The distributor of this application has low operating flexibility. If the reflux volume is too much, it is easy to cause the liquid to overflow to the top of the air duct, affecting the distribution uniformity. Summary of the invention

[0005] The purpose of the present invention is to provide a packed tower distillation system and a distillation process based on a two-stage distributor in order to solve the above-mentioned technical problems, so as to achieve two-stage distribution of liquid, have large operation flexibility and be able to cope with the situation of large reflux volume.

[0006] In view of this, the present invention provides a packed tower distillation system based on a two-stage distributor, comprising:

[0007] A packed tower, wherein a two-stage distributor is provided at the top of the packed tower, a two-stage redistributor is provided in the tower, a first gas outlet and a reflux port are provided at the top of the tower, and a first gas inlet and a first liquid outlet are provided at the bottom of the tower;

[0008] An evaporating kettle, wherein the evaporating kettle is provided with a liquid return port connected to the first liquid outlet and a second gas outlet connected to the first gas inlet;

[0009] A condenser, wherein the condenser is provided with a second air inlet and a second liquid outlet, wherein the second air inlet is connected to the first air outlet, and the second liquid outlet is connected to the reflux port;

[0010] A storage tank, wherein the storage tank is provided with a liquid inlet connected to the second liquid outlet;

[0011] Wherein, valves are arranged between the second liquid outlet and the reflux port and between the second liquid outlet and the liquid inlet, and a sampling valve is also arranged between the second liquid outlet and the liquid inlet.

[0012] In this technical solution, by adopting a two-stage distributor and a two-stage redistributor, it is convenient to adjust the distributor and the redistributor according to the reflux volume, so as to avoid overflow due to excessive reflux volume, resulting in uneven liquid distribution, and the operation is flexible and stable.

[0013] In the above technical solution, further, it also includes:

[0014] A liquid collecting device, which is installed in the packed tower and is installed above the two-stage distributor and above the two-stage redistributor respectively;

[0015] Wherein, the two-stage distributor and the two-stage redistributor both include:

[0016] The liquid receiving hopper is installed below the liquid collecting device, and the liquid collecting device guides the liquid into the liquid receiving hopper, and a filter screen is installed in the liquid receiving hopper;

[0017] A first distribution pipe is installed below the liquid receiving hopper and is connected to the outlet at the bottom of the liquid receiving hopper by a first connecting pipe;

[0018] A second distribution pipe, the second distribution pipe is installed below the first distribution pipe and is connected to the bottom surface of the first distribution pipe by a second connecting pipe;

[0019] Wherein, a plurality of small holes are provided on the bottom surfaces of the first distribution pipe and the second distribution pipe.

[0020] In the present technical solution, the liquid collecting device is used to collect the refluxed liquid and introduce it into the liquid receiving bucket, so that the first distribution pipe and the second distribution pipe can evenly distribute the liquid. When the reflux amount is small, only the second distribution pipe arranged in the lower layer is used for distribution. When the reflux amount is large, the liquid overflows to the first distribution pipe, and the first distribution pipe on the upper layer is started, thereby avoiding liquid overflow and affecting the uniformity of liquid distribution. The filter net can block granular foreign matter and impurities to prevent clogging of small holes.

[0021] In the above technical solution, further, the first distribution pipe includes:

[0022] A first main pipe, the first main pipe is connected to the liquid receiving bucket through a first connecting pipe;

[0023] A first branch pipe, which is in multiple numbers and is installed on the bottom surface of the first main pipe, and a first connecting hole is provided at the connection with the first main pipe;

[0024] Wherein, a plurality of small holes are opened on the bottom surface of the first branch pipe, and the ports of the first main pipe and the first branch pipe are both closed, and a gas phase channel is formed between adjacent first branch pipes.

[0025] In the present technical solution, by configuring the first distribution pipe to be a first main pipe and a plurality of first branch pipes, the first main pipe serves as a guide to facilitate the flow of liquid to the plurality of first branch pipes, and then the plurality of first branch pipes facilitate uniform distribution of the liquid, and a gas phase channel is formed between adjacent first branch pipes. The plurality of gas phase channels can effectively avoid gas resistance and increased pressure drop, and have a buffering and reducing effect on abnormal phenomena such as liquid flooding and material rushing in the tower.

[0026] In the above technical solution, further, the second distribution pipe includes:

[0027] a second main pipe, the second main pipe is connected to the first main pipe through a second connecting pipe;

[0028] A second branch pipe, which is in multiple numbers and is installed on the bottom surface of the second main pipe, and a second connecting hole is provided at the connection with the second main pipe;

[0029] Wherein, a plurality of small holes are opened on the bottom surface of the second branch pipe, and the ports of the second main pipe and the second branch pipe are both closed, and a gas phase channel is formed between adjacent second branch pipes.

[0030] In the present technical solution, by configuring the second distribution pipe to be a second main pipe and a plurality of second branch pipes, the second main pipe serves as a guide to facilitate the flow of liquid to the plurality of second branch pipes, and then the plurality of second branch pipes facilitate uniform distribution of the liquid, and a gas phase channel is formed between adjacent second branch pipes. The plurality of gas phase channels can effectively avoid gas resistance and increased pressure drop, and have a buffering and reducing effect on abnormal phenomena such as liquid flooding and material rushing in the tower.

[0031] In the above technical solution, further:

[0032] The first branch pipe and the second branch pipe are arranged alternately on the same longitudinal plane;

[0033] The small holes on the first branch pipe and the small holes on the second branch pipe are arranged alternately on the same horizontal plane.

[0034] In the present technical solution, the first branch pipe and the second branch pipe are staggered and distributed on the same longitudinal plane, and the small holes on the first branch pipe and the small holes on the second branch pipe are staggered and distributed on the same horizontal plane, and the first branch pipe and the second branch pipe are respectively located at different levels, thereby effectively improving the uniform distribution of the liquid without affecting the gas phase channel, and the distribution points are multiplied, thereby greatly improving the distribution effect.

[0035] In the above technical solution, further:

[0036] The diameter of the small hole on the first branch pipe is larger than the diameter of the small hole on the second branch pipe.

[0037] In the present technical solution, by setting the diameter of the small hole on the first branch pipe at the upper layer to be larger than the diameter of the small hole on the second branch pipe at the lower layer, the flow rate can be increased exponentially when the reflux volume is large, effectively preventing the liquid from overflowing the liquid receiving bucket and affecting the uniformity of the liquid distribution.

[0038] In the above technical solution, further:

[0039] The diameter size of the small hole on the same first branch pipe and the diameter size of the small hole on the same second branch pipe are increased successively along the side close to the inner wall of the packed tower.

[0040] In the technical solution, through the above arrangement, the same first branch pipe or second branch pipe can promote the liquid to flow more easily to the side close to the inner wall of the packed tower, thereby ensuring that all the small holes on the same first branch pipe or second branch pipe participate and ensuring the uniformity of liquid distribution.

[0041] In the above technical solution, further, the liquid collecting device includes:

[0042] A flow guide hopper is installed above the liquid receiving hopper and is provided with a flow guide hole corresponding to the liquid receiving hopper;

[0043] A guide tube, which is installed on the inner wall of the guide hole;

[0044] The drainage component is installed on the diversion bucket and is used to drain the liquid into the diversion bucket.

[0045] In the present technical solution, the guide bucket is used to guide the liquid flowing down from the drainage component to the guide hole, and the setting of the guide tube can eliminate the horizontal flow of the liquid caused by the guide bucket, so that the liquid is twisted at the guide hole to form a vertical downward flow, thereby facilitating the liquid to enter the liquid receiving bucket and preventing the liquid from splashing out of the liquid receiving bucket.

[0046] In the above technical solution, further, the drainage component includes:

[0047] Drainage buckets, there are multiple drainage buckets, which are installed on the diversion buckets at equal intervals and are provided with drainage holes corresponding to the diversion buckets;

[0048] A drainage tube, one end of which is connected to the inner wall of the drainage hole and the other end of which extends into the diversion bucket;

[0049] Drainage inclined plates, there are multiple drainage inclined plates, one end of which is respectively connected to multiple drainage buckets, and the other end extends to the top of the adjacent drainage bucket to form a drainage folded plate;

[0050] Wherein, a gas phase channel is formed between two adjacent drainage inclined plates.

[0051] In the present technical solution, the refluxed liquid is guided into the drainage bucket through a plurality of drainage inclined plates, thereby facilitating the liquid to enter the drainage bucket through the drainage hole, and the drainage tube can eliminate the horizontal flow of the liquid caused by the drainage bucket, prompting the liquid to twist at the drainage hole to form a vertical downward flow, thereby facilitating the liquid to enter the drainage bucket and preventing the liquid from splashing out of the drainage bucket.

[0052] The present invention provides a distillation process of a packed tower distillation system based on a two-stage distributor, comprising the following steps:

[0053] S1: The evaporator heats and evaporates the material, so that it enters the bottom of the packed tower through the second gas outlet and the first gas inlet, and rises along the packed tower;

[0054] S2: Steam enters the condenser through the first gas outlet and the second gas inlet, and the valve between the second liquid outlet and the liquid inlet is closed, so that the liquid flowing out of the second liquid outlet of the condenser is completely refluxed to the liquid collecting device in the packed tower, and enters the two-stage distributor and the two-stage redistributor through the liquid collecting device;

[0055] At this time, the reflux liquid is large, and the second distribution pipe cannot discharge the liquid in time. The liquid in the distribution pipe overflows to the first distribution pipe through the second connecting pipe, thereby ensuring that the gas phase channel remains unchanged while increasing the liquid falling density, thereby promoting the exchange and mass transfer between the falling liquid and the rising steam;

[0056] S3: Detect the reflux liquid through the pressure valve. If it meets the requirements, open the valve between the second liquid outlet and the liquid inlet to let the liquid that meets the requirements flow into the storage tank, and return part of the liquid to the packing tower;

[0057] At this time, the reflux liquid is significantly reduced. When the second distribution pipe is drained in time, the liquid drops in the second connecting pipe, so that the liquid is distributed only through the first distribution pipe, and in the change of the reflux amount, the second distribution pipe is automatically controlled to participate in the liquid distribution.

[0058] S4: After the distillation is completed, close the valve between the second liquid outlet and the reflux port to allow the liquid to flow into the storage tank.

[0059] In the present technical scheme, when the liquid flow rate is small, only the second branch of the lower layer works, and the small hole structure ensures the uniformity of the distribution points. When the liquid flow rate increases, the second branch of the lower layer continues to work, and the liquid level in the second connecting pipe rises until it exceeds the first branch. The first branch and the second branch of the upper and lower layers are both working. At this time, the two layers of distribution points are sprayed evenly and the points are doubled, which greatly improves the distribution and redistribution effects. The distributor and the redistributor have large operational flexibility and have good performance under various types of operating conditions. They have wide applicability and can be applied to pressurized and normal pressure reduction conditions, large or small liquid-to-gas ratios, gas velocities in the tower, and liquid spray volumes. Moreover, since the structure of the distributor and the redistributor is gravity self-flowing, it is basically not affected by the pressure in the tower, and can be applied to various pressure conditions. The multi-layer structure forms a larger gas phase channel, which can be automatically adjusted under various relatively harsh gas-liquid conditions, and has a good distribution effect.

[0060] The beneficial effects of the present invention are:

[0061] 1. Through the liquid collecting device, it is convenient to collect the refluxed liquid and guide it into the liquid receiving hopper, so that the first distribution pipe and the second distribution pipe can evenly distribute the liquid. When the reflux amount is small, only the second distribution pipe arranged at the lower layer is used for distribution. When the reflux amount is large, the liquid overflows to the first distribution pipe, and the first distribution pipe at the upper layer is started, so as to avoid liquid overflow and affect the uniformity of liquid distribution. The filter can block granular foreign matter and impurities to prevent clogging of small holes.

[0062] 2. By staggering the first branch pipe and the second branch pipe on the same longitudinal plane, and staggering the small holes on the first branch pipe and the small holes on the second branch pipe on the same horizontal plane, and the first branch pipe and the second branch pipe are respectively located at different levels, the uniform distribution of the liquid can be effectively improved without affecting the gas phase channel, and the distribution points are multiplied, thereby greatly improving the distribution effect;

[0063] 3. The guide hopper and multiple drainage inclined plates can guide the refluxed liquid. The guide tube and drainage tube can eliminate the horizontal flow of the liquid caused by the guide hopper and drainage hopper, and cause the liquid to twist at the guide hole and drainage hole to form a vertical downward flow, thereby facilitating the liquid to enter the guide hopper and liquid receiving hopper, and preventing the liquid from splashing out of the guide hopper and liquid receiving hopper;

[0064] 4. The operation flexibility of the distributor and redistributor is large, and they have good performance under various types of operating conditions. They have wide applicability and can be applied to pressurized and normal reduced pressure conditions, large or small liquid-gas ratios, gas velocities in the tower, and liquid spray volumes. Moreover, since the structure of the distributor and redistributor is gravity self-flowing, they are basically not affected by the pressure in the tower and can be applied to various pressure conditions. The multi-layer structure forms a larger gas phase channel, which can be automatically adjusted under various relatively harsh gas-liquid conditions and has a better distribution effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of the structure of the present invention;

[0066] Figure 2 It is a schematic structural diagram of a packed tower of the present invention;

[0067] Figure 3 The present invention Figure 2 The enlarged view of point A in the middle;

[0068] Figure 4 is a bottom view of the distributor of the present invention;

[0069] The symbols in the figure are as follows: 1, packed tower; 2, two-stage distributor; 3, two-stage redistributor; 20, liquid receiving bucket; 21, filter screen; 22, first distribution pipe; 220, first main pipe; 221, first branch pipe; 222, first connecting hole; 23, first connecting pipe; 24, second distribution pipe; 240, second main pipe; 241, second branch pipe; 242, second connecting hole; 25, second connecting pipe; 26, small hole; 4, first air outlet; 5, reflux port; 6, first air inlet; 7, first liquid outlet; 8, evaporator; 9 , liquid return port; 10, second air outlet; 11, condenser; 12, second air inlet; 13, second liquid outlet; 14, storage tank; 15, liquid inlet; 16, valve; 17, sampling valve; 18, liquid collecting device; 180, guide bucket; 181, guide hole; 182, guide tube; 183, drainage assembly; 1830, drainage bucket; 1831, drainage hole; 1832, drainage tube; 1833, drainage inclined plate; 1834, drainage folding plate; 190, float; 191, first limit rod; 192, second limit rod. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0071] Embodiment 1:

[0072] This embodiment provides a packed tower distillation system based on a two-stage distributor, comprising:

[0073] A packed tower 1, wherein a two-stage distributor 2 is provided at the top of the packed tower 1, a two-stage redistributor 3 is provided in the tower, a first gas outlet 4 and a reflux port 5 are provided at the top of the tower, a first gas inlet 6 and a first liquid outlet 7 are provided at the top of the tower;

[0074] The evaporator 8 is provided with a liquid return port 9 connected to the first liquid outlet 7 and a second gas outlet 10 connected to the first gas inlet 6;

[0075] The condenser 11 is provided with a second air inlet 12 and a second liquid outlet 13, wherein the second air inlet 12 is communicated with the first air outlet 4, and the second liquid outlet 13 is communicated with the reflux port 5;

[0076] A storage tank 14, wherein the storage tank 14 is provided with a liquid inlet 15 communicating with the second liquid outlet 13;

[0077] Among them, valves 16 are provided between the second liquid outlet 13 and the reflux port 5 and between the second liquid outlet 13 and the liquid inlet 15, and a sampling valve 17 is also provided between the second liquid outlet 13 and the liquid inlet 15;

[0078] Meanwhile, the evaporator 8, the condenser 11, the storage tank 14, the valve 16 and the pressure-taking valve are all existing mature technologies, and their specific structures are not described here any more.

[0079] It can be seen from this embodiment that by adopting the two-stage distributor 2 and the two-stage redistributor 3, it is convenient to adjust the distributor and the redistributor according to the reflux amount, so as to avoid overflow due to excessive reflux amount, resulting in uneven liquid distribution, and the operation is flexible and stable.

[0080] Embodiment 2:

[0081] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features, and also includes:

[0082] The liquid collecting device 18 is installed in the packed tower 1 and is installed above the two-stage distributor 2 and above the two-stage redistributor 3 respectively;

[0083] Wherein, the two-stage distributor 2 and the two-stage redistributor 3 both include:

[0084] The liquid receiving hopper 20 is installed below the liquid collecting device 18, and the liquid collecting device 18 introduces the liquid into the liquid receiving hopper 20, and a filter screen 21 is installed in the liquid receiving hopper 20;

[0085] A first distribution pipe 22, which is installed below the liquid receiving bucket 20 and is connected to the outlet at the bottom of the liquid receiving bucket 20 by a first connecting pipe 23;

[0086] A second distribution pipe 24 is installed below the first distribution pipe 22 and is connected to the bottom surface of the first distribution pipe 22 by a second connecting pipe 25;

[0087] The bottom surfaces of the first distribution pipe 22 and the second distribution pipe 24 are both provided with a plurality of small holes 26;

[0088] Meanwhile, the liquid receiving hopper 20 and the first connecting pipe 23 are preferably connected by welding, and the filter screen 21 and the liquid receiving hopper 20 are preferably connected by snap-fit ​​connection.

[0089] It can be seen from the present embodiment that the liquid collecting device 18 facilitates the collection of refluxed liquid and its introduction into the liquid receiving bucket 20, thereby facilitating the first distribution pipe 22 and the second distribution pipe 24 to evenly distribute the liquid. When the reflux amount is small, only the second distribution pipe 24 arranged at the lower layer is used for distribution. When the reflux amount is large, the liquid overflows to the first distribution pipe 22, and the first distribution pipe 22 at the upper layer is started, thereby avoiding liquid overflow and affecting the uniformity of liquid distribution. The filter screen 21 can block granular foreign matter and impurities to prevent clogging of the small holes 26.

[0090] Embodiment 3:

[0091] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features: the first distribution pipe 22 includes:

[0092] A first main pipe 220, the first main pipe 220 is connected to the liquid receiving bucket 20 via a first connecting pipe 23;

[0093] A first branch pipe 221, which is in plurality and is installed on the bottom surface of the first main pipe 220, and a first connecting hole 222 is provided at the connection with the first main pipe 220;

[0094] Among them, a plurality of small holes 26 are opened on the bottom surface of the first branch pipe 221, and the ports of the first main pipe 220 and the first branch pipe 221 are closed, and a gas phase channel is formed between adjacent first branch pipes 221;

[0095] At the same time, welding is preferably used between the first main pipe 220 and the first connecting pipe 23, the first branch pipe 221 and the second connecting pipe 25, and the first branch pipe 221 can adopt different lengths according to the structure inside the packed tower 1, that is, the ends of multiple first branch pipes 221 away from the center form an approximately circular shape.

[0096] It can be seen from the present embodiment that by configuring the first distribution pipe 22 to be a first main pipe 220 and a plurality of first branch pipes 221, the first main pipe 220 serves as a guide, facilitating the liquid to flow to the plurality of first branch pipes 221, and then the plurality of first branch pipes 221 facilitate uniform distribution of the liquid, and a gas phase channel is formed between adjacent first branch pipes 221. The plurality of gas phase channels can effectively avoid gas resistance and increased pressure drop, and have a buffering and reducing effect on abnormal phenomena such as liquid flooding and material rushing in the tower.

[0097] Embodiment 4:

[0098] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features: the second distribution pipe 24 includes:

[0099] A second main pipe 240, the second main pipe 240 is connected to the first main pipe 220 via a second connecting pipe 25;

[0100] A second branch pipe 241, which is in plurality and is installed on the bottom surface of the second main pipe 240, and a second connecting hole 242 is provided at the connection with the second main pipe 240;

[0101] Among them, a plurality of small holes 26 are opened on the bottom surface of the second branch pipe 241, and the ports of the second main pipe 240 and the second branch pipe 241 are closed, and a gas phase channel is formed between adjacent second branch pipes 241;

[0102] At the same time, welding is preferably used between the second main pipe 240 and the second branch pipe 241 and the second connecting pipe 25, and the second branch pipe 241 can adopt different lengths according to the internal structure of the packed tower 1, that is, the ends of multiple second branch pipes 241 away from the center form an approximately circular shape, and brackets for connecting the distributor and the redistributor to the inner wall of the packed tower 1 are also provided at both ends of the second main pipe 240.

[0103] It can be seen from the present embodiment that by configuring the second distribution pipe 24 to be a second main pipe 240 and a plurality of second branch pipes 241, the second main pipe 240 serves as a guide, facilitating the liquid to flow to the plurality of second branch pipes 241, and then the plurality of second branch pipes 241 facilitate uniform distribution of the liquid, and a gas phase channel is formed between adjacent second branch pipes 241. The plurality of gas phase channels can effectively avoid gas resistance and increased pressure drop, and have a buffering and reducing effect on abnormal phenomena such as liquid flooding and material rushing in the tower.

[0104] Embodiment 5:

[0105] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features:

[0106] The first branch pipe 221 and the second branch pipe 241 are arranged alternately on the same longitudinal plane;

[0107] The small holes 26 on the first branch pipe 221 and the small holes 26 on the second branch pipe 241 are arranged alternately on the same horizontal plane.

[0108] It can be seen from the present embodiment that by staggeredly arranging the first branch pipe 221 and the second branch pipe 241 on the same longitudinal plane and staggeredly arranging the small holes 26 on the first branch pipe 221 and the small holes 26 on the second branch pipe 241 on the same horizontal plane, and the first branch pipe 221 and the second branch pipe 241 are respectively located at different levels, the uniform distribution of the liquid can be effectively improved without affecting the gas phase channel, the distribution points are multiplied, and the distribution effect is greatly improved.

[0109] Embodiment 6:

[0110] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features:

[0111] The diameter of the small hole 26 on the first branch pipe 221 is greater than the diameter of the small hole 26 on the second branch pipe 241 .

[0112] It can be seen from the present embodiment that by setting the diameter of the small hole 26 on the first branch pipe 221 of the upper layer to be larger than the diameter of the small hole 26 on the second branch pipe 241 of the lower layer, when the reflux volume is large, the flow rate can be increased exponentially, thereby effectively preventing the liquid from overflowing the liquid receiving bucket 20 and affecting the uniformity of the liquid distribution.

[0113] Embodiment 7:

[0114] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features:

[0115] The diameter of the small hole 26 on the same first branch pipe 221 and the diameter of the small hole 26 on the same second branch pipe 241 both increase successively along the side close to the inner wall of the packed tower 1 .

[0116] It can be seen from this embodiment that, through the above arrangement, the same first branch pipe 221 or the second branch pipe 241 can promote the liquid to flow more easily to the side close to the inner wall of the packed tower 1, thereby ensuring that the small holes 26 on the same first branch pipe 221 or the second branch pipe 241 are all involved, thereby ensuring the uniformity of liquid distribution.

[0117] Embodiment 8:

[0118] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features. The liquid collecting device 18 includes:

[0119] A flow guide hopper 180, which is installed above the liquid receiving hopper 20 and has a flow guide hole 181 corresponding to the liquid receiving hopper 20;

[0120] A flow guide tube 182, which is installed on the inner wall of the flow guide hole 181;

[0121] A drainage component 183, which is installed on the diversion bucket 180 and is used to divert liquid into the diversion bucket 180;

[0122] The guide scoop 180 and the guide tube 182 are preferably welded together; and brackets for connecting the liquid collecting device 18 and the inner wall of the packing tower 1 are provided at both ends of the guide scoop 180 .

[0123] It can be seen from the present embodiment that the guide bucket 180 can facilitate the liquid flowing down from the drainage component 183 to be guided to the guide hole 181, and the setting of the guide tube 182 can eliminate the horizontal flow of the liquid caused by the guide bucket 180, causing the liquid to twist at the guide hole 181 to form a vertical downward flow, thereby facilitating the liquid to enter the liquid receiving bucket 20 and preventing the liquid from splashing out of the liquid receiving bucket 20.

[0124] Embodiment 9:

[0125] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features. The drainage component 183 includes:

[0126] Drainage bucket 1830, there are multiple drainage buckets 1830, and they are installed on the guide bucket 180 at equal intervals, and are provided with drainage holes 1831 corresponding to the guide bucket 180;

[0127] A drainage tube 1832, one end of which is connected to the inner wall of the drainage hole 1831, and the other end of which extends into the guide bucket 180;

[0128] Drainage inclined plates 1833, there are multiple drainage inclined plates 1833, one end of which is respectively connected to multiple drainage buckets 1830, and the other end extends to the top of the adjacent drainage bucket 1830 to form a drainage folding plate 1834;

[0129] Wherein, a gas phase channel is formed between two adjacent drainage inclined plates 1833;

[0130] At the same time, welding is preferably used between the drainage bucket 1830 and the guide bucket 180, the drainage tube 1832 and the drainage inclined plate 1833, and the inclination angles of the drainage inclined plate 1833 and the drainage folding plate 1834 are both 30°-60°.

[0131] It can be seen from the present embodiment that the refluxed liquid is guided into the drainage bucket 1830 through a plurality of drainage inclined plates 1833, thereby facilitating the liquid to enter the diversion bucket 180 through the drainage hole 1831, and the drainage tube 1832 can eliminate the horizontal flow of the liquid caused by the drainage bucket 1830, causing the liquid to twist at the drainage hole 1831 to form a vertical downward flow, thereby facilitating the liquid to enter the diversion bucket 180 and preventing the liquid from splashing out of the diversion bucket 180.

[0132] Embodiment 10:

[0133] This embodiment provides a packed tower distillation system based on a two-stage distributor, which, in addition to the technical solutions of the above embodiments, also has the following technical features, and also includes:

[0134] A float 190, which is installed at the connection between the second connecting pipe 25 and the second main pipe 240;

[0135] A first limiting rod 191, which is installed at the connection between the second main pipe 240 and the second connecting pipe 25 and is used to limit the horizontal direction of the float 190;

[0136] A second limiting rod 192, which is installed on the inner wall of the second connecting pipe 25 and is used to limit the float 190 in the vertical direction;

[0137] Among them, the diameter of the float 190 is preferably smaller than the diameter of the second connecting pipe 25, and when not working, the gap area at the connection between the surface of the float 190 and the second connecting pipe 25 and the second main pipe 240 is not less than the cross-sectional area of ​​the second connecting pipe 25, and at the same time, the buoyancy of the float 190 is greater than the gravity of the liquid on the float 190 when the second connecting pipe 25 is filled.

[0138] It can be seen from the present embodiment that by setting the float 190, when the reflux volume is large, the first branch pipe 221 cannot drain the liquid in time, thereby causing the water level in the second main pipe 240 to rise, thereby pushing the float 190 to rise. Due to the setting of the first limit rod 191, the float 190 enters from the bottom end of the second connecting pipe 25, and the liquid channel discharged from the second connecting pipe 25 into the second main pipe 240 becomes smaller, so that the speed at which the liquid enters the top end of the second connecting pipe 25 is greater than the speed at which the liquid flows out of the bottom end of the second connecting pipe 25, thereby accelerating the filling of the space above the float 190 in the second connecting pipe 25, so that when the second main pipe 240 is not filled, the water level can rise to the first main pipe 220, thereby accelerating the start-up of the first distribution pipe 22, shortening the adjustment switching time between the single-stage distribution and the two-stage distribution of the distributor and the redistributor, and improving work efficiency.

[0139] Embodiment 11:

[0140] This embodiment provides a distillation process of a packed tower distillation system based on a two-stage distributor, comprising the following steps:

[0141] S1: The evaporator 8 heats and evaporates the material, so that the material enters the bottom of the packed tower 1 through the second gas outlet 10 and the first gas inlet 6, and rises along the packed tower 1;

[0142] S2: The steam enters the condenser 11 through the first gas outlet 4 and the second gas inlet 12, and the valve 16 between the second liquid outlet 13 and the liquid inlet 15 is closed, so that the liquid flowing out of the second liquid outlet 13 of the condenser 11 is completely refluxed to the liquid collecting device 18 in the packed tower 1, and enters the two-stage distributor 2 and the two-stage redistributor 3 through the liquid collecting device 18;

[0143] At this time, the reflux liquid is large, and the second distribution pipe 24 cannot discharge the liquid in time. The liquid in the distribution pipe overflows to the first distribution pipe 22 through the second connecting pipe 25, thereby ensuring that the gas phase channel remains unchanged and increasing the liquid falling density, thereby promoting the exchange and mass transfer between the falling liquid and the rising steam.

[0144] S3: Detect the reflux liquid through the pressure valve, and if it meets the requirements, open the valve 16 between the second liquid outlet 13 and the liquid inlet 15 to let the liquid that meets the requirements flow into the storage tank 14, and return part of the liquid to the packed tower 1;

[0145] At this time, the reflux liquid is significantly reduced. When the second distribution pipe 24 is discharged in time, the liquid drops in the second connecting pipe 25, so that the liquid is distributed only through the first distribution pipe 22, and in the change of the reflux amount, the second distribution pipe 24 is automatically controlled to participate in the liquid distribution.

[0146] S4: After the distillation is completed, the valve 16 between the second liquid outlet 13 and the reflux port 5 is closed, so that the liquid completely flows into the storage tank 14 .

[0147] It can be seen from the present embodiment that when the liquid flow rate is relatively small, only the second branch pipe 241 of the lower layer works, and the small hole 26 structure ensures the uniformity of the distribution points. When the liquid flow rate increases, the second branch pipe 241 of the lower layer continues to work, and the liquid level in the second connecting pipe 25 rises until it exceeds the first branch pipe 221. The first branch pipe 221 and the second branch pipe 241 of the upper and lower layers both work. At this time, the two layers of distribution points are sprayed evenly and the points are doubled, which greatly improves the distribution and redistribution effects. The distributor and the redistributor have large operational flexibility and have good performance under various types of operating conditions. They have wide applicability and can be applied to pressurized and normal pressure reduction conditions, large or small liquid-to-gas ratios, gas velocities in the tower, and liquid spraying volumes. Moreover, since the structure of the distributor and the redistributor is gravity self-flowing, it is basically not affected by the pressure in the tower, and can be applied to various pressure conditions. The multi-layer structure forms a larger gas phase channel, which can be automatically adjusted under various relatively harsh gas-liquid conditions, and has a good distribution effect.

[0148] The embodiments of the present application are described above in conjunction with the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A packed tower distillation system based on a two-stage distributor, characterized in that: include: A packed tower (1), wherein a two-stage distributor (2) is provided at the top of the packed tower (1), a two-stage redistributor (3) is provided in the tower, a first gas outlet (4) and a reflux port (5) are provided at the top of the tower, and a first gas inlet (6) and a first liquid outlet (7) are provided at the bottom of the tower; An evaporating kettle (8), wherein the evaporating kettle (8) is provided with a liquid return port (9) connected to the first liquid outlet (7) and a second gas outlet (10) connected to the first gas inlet (6); A condenser (11), wherein the condenser (11) is provided with a second air inlet (12) and a second liquid outlet (13), wherein the second air inlet (12) is connected to the first air outlet (4), and the second liquid outlet (13) is connected to the reflux port (5); A storage tank (14), wherein the storage tank (14) is provided with a liquid inlet (15) connected to the second liquid outlet (13); A valve (16) is provided between the second liquid outlet (13) and the reflux port (5) and between the second liquid outlet (13) and the liquid inlet (15), and a sampling valve (17) is also provided between the second liquid outlet (13) and the liquid inlet (15); A liquid collecting device (18), wherein the liquid collecting device (18) is installed in the packed tower (1) and is installed above the two-stage distributor (2) and above the two-stage redistributor (3) respectively; Wherein, the two-stage distributor (2) and the two-stage redistributor (3) both include: A liquid receiving hopper (20), wherein the liquid receiving hopper (20) is installed below the liquid collecting device (18); A first distribution pipe (22), the first distribution pipe (22) is installed below the liquid receiving bucket (20) and comprises a first main pipe (220), and a first connecting pipe (23) is provided between the first main pipe (220) and the outlet at the bottom end of the liquid receiving bucket (20); A second distribution pipe (24), the second distribution pipe (24) is installed below the first distribution pipe (22) and comprises a second main pipe (240), a second connecting pipe (25) is provided between the second main pipe (240) and the bottom surface of the first distribution pipe (22) for communication; Wherein, the bottom surfaces of the first distribution pipe (22) and the second distribution pipe (24) are both provided with a plurality of small holes (26); A floating ball (190), the floating ball (190) being installed at the connection between the second connecting pipe (25) and the second main pipe (240); A first limiting rod (191), the first limiting rod (191) being installed on the second main pipe (240) at a connection between the second main pipe (240) and the second connecting pipe (25), and being used to limit the horizontal direction of the floating ball (190); A second limiting rod (192), the second limiting rod (192) being mounted on the inner wall of the second connecting pipe (25) and used to limit the floating ball (190) in a vertical direction; The diameter of the float (190) is smaller than the diameter of the second connecting tube (25), and when not in operation, the gap area between the surface of the float (190) and the connection between the second connecting tube (25) and the second main tube (240) is not less than the cross-sectional area of ​​the second connecting tube (25), and the buoyancy of the float (190) is greater than the gravity of the liquid on the float (190) when the second connecting tube (25) is filled.

2. The packed tower distillation system based on a two-stage distributor according to claim 1, characterized in that: The liquid is introduced into the liquid receiving bucket (20) by the liquid collecting device (18), and a filter screen (21) is installed in the liquid receiving bucket (20).

3. The packed tower distillation system based on the two-stage distributor according to claim 2, characterized in that: The first distribution pipe (22) further comprises: A first branch pipe (221), wherein the first branch pipe (221) is in plurality and is installed on the bottom surface of the first main pipe (220), and a first connecting hole (222) is provided at the connection with the first main pipe (220) for communication; A plurality of small holes (26) are provided on the bottom surface of the first branch pipe (221), and the ports of the first main pipe (220) and the first branch pipe (221) are both closed, and a gas phase channel is formed between adjacent first branch pipes (221).

4. The packed tower distillation system based on a two-stage distributor according to claim 2, characterized in that: The second distribution pipe (24) further comprises: A second branch pipe (241), wherein the second branch pipe (241) is in plurality and is installed on the bottom surface of the second main pipe (240), and a second connecting hole (242) is provided at the connection with the second main pipe (240) for communication; A plurality of small holes (26) are provided on the bottom surface of the second branch pipe (241), and the ports of the second main pipe (240) and the second branch pipe (241) are both closed, and a gas phase channel is formed between adjacent second branch pipes (241).

5. The packed tower distillation system based on a two-stage distributor according to claim 3 or 4, characterized in that: The first branch pipe (221) and the second branch pipe (241) are arranged alternately on the same longitudinal plane; The small holes (26) on the first branch pipe (221) and the small holes (26) on the second branch pipe (241) are arranged alternately on the same horizontal plane.

6. The packed tower distillation system based on the two-stage distributor according to claim 5, characterized in that: The diameter of the small hole (26) on the first branch pipe (221) is greater than the diameter of the small hole (26) on the second branch pipe (241).

7. The packed tower distillation system based on the two-stage distributor according to claim 6, characterized in that: The diameter of the small hole (26) on the same first branch pipe (221) and the diameter of the small hole (26) on the same second branch pipe (241) both increase successively along the side close to the inner wall of the packed tower (1).

8. The packed tower distillation system based on a two-stage distributor according to claim 2, characterized in that: The liquid collecting device (18) comprises: A flow guide hopper (180), the flow guide hopper (180) being installed above the liquid receiving hopper (20) and being provided with a flow guide hole (181) corresponding to the liquid receiving hopper (20); A flow guide tube (182), wherein the flow guide tube (182) is installed on the inner wall of the flow guide hole (181); A drainage component (183) is installed on the diversion bucket (180) and is used to drain liquid into the diversion bucket (180).

9. The packed tower distillation system based on a two-stage distributor according to claim 8, characterized in that: The drainage assembly (183) comprises: A flow guide bucket (1830), wherein the flow guide bucket (1830) is in plurality and is installed on the flow guide bucket (180) at equal intervals and is provided with a flow guide hole (1831) corresponding to the flow guide bucket (180); A drainage tube (1832), one end of which is connected to the inner wall of the drainage hole (1831) and the other end of which extends into the guide bucket (180); A plurality of diversion inclined plates (1833), one end of which is respectively connected to a plurality of diversion buckets (1830), and the other end of which extends to the top of an adjacent diversion bucket (1830) to form a diversion folded plate (1834); Wherein, a gas phase channel is formed between two adjacent drainage inclined plates (1833).

10. The packed tower distillation system based on a two-stage distributor according to claim 7 or 9, characterized in that: The distillation process includes the following steps: S1: The evaporator (8) heats and evaporates the material, so that the material enters the bottom of the packed tower (1) through the second gas outlet (10) and the first gas inlet (6), and rises along the packed tower (1); S2: Steam enters the condenser (11) through the first gas outlet (4) and the second gas inlet (12), and the valve (16) between the second liquid outlet (13) and the liquid inlet (15) is closed, so that the liquid flowing out of the second liquid outlet (13) of the condenser (11) is completely refluxed to the liquid collecting device (18) in the packed tower (1), and enters the two-stage distributor (2) and the two-stage redistributor (3) through the liquid collecting device (18); At this time, the reflux liquid is relatively large, and the second distribution pipe (24) cannot discharge the liquid in time, so the liquid in the distribution pipe overflows to the first distribution pipe (22) through the second connecting pipe (25), thereby increasing the liquid falling density while ensuring that the gas phase channel remains unchanged, thereby promoting the exchange and mass transfer between the falling liquid and the rising steam; S3: The reflux liquid is tested through the pressure-taking valve. If the liquid meets the requirements, the valve (16) between the second liquid outlet (13) and the liquid inlet (15) is opened to allow the liquid that meets the requirements to flow into the storage tank (14), and part of the liquid is refluxed to the packing tower (1); At this time, the reflux liquid is significantly reduced, and when the second distribution pipe (24) is drained in time, the liquid drops in the second connecting pipe (25), so that the liquid is distributed only through the first distribution pipe (22), and when the reflux amount changes, the second distribution pipe (24) is automatically controlled to participate in the liquid distribution; S4: After the distillation is completed, the valve (16) between the second liquid outlet (13) and the reflux port (5) is closed to allow the liquid to flow completely into the storage tank (14).

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