Series rectifying recovery apparatus, method and use thereof

Abstract

The application discloses a series connection type rectification recovery device and a method and application thereof. The series connection type rectification recovery device comprises a distillation assembly, a rectification tower, a reboiler and a tower top condenser. The distillation assembly comprises a plurality of distillation kettles and liquid inlet pumps. The plurality of distillation kettles are connected in series. Liquid inlet pumps are connected between adjacent distillation kettles. The bottom of the last distillation kettle is connected with a discharge pipe for discharging. The top of each distillation kettle is connected with the rectification tower through a pipeline. The rectification tower is used for collecting steam of the distillation assembly and performing fractionation. The reboiler is connected with the bottom of the rectification tower for reboiling heavy distillates. The tower top condenser is connected with the top of the rectification tower for condensing light distillates of the rectification tower. The recovery device can save equipment and energy, keep the components of the inlet gas basically constant, ensure the quality of rectification, realize continuous operation, gather all concentrated products in one discharge kettle for automatic discharge, and save operation labor.

Description

TECHNICAL FIELD

[0001] The present application relates to the fields of medicine and chemical industry, in particular to a series connection type rectification recovery device, method and application thereof. BACKGROUND

[0002] Pharmaceutical factories and chemical factories need to recover solvents and products containing solid mother liquor. The common property of solvents containing solid mother liquor is that solids are usually dissolved in solvents. The solids in the initial state of the mother liquor are not precipitated, and as the rectification proceeds, the content of the solvent gradually decreases, and the solids originally dissolved in the liquid completely precipitate. At this time, if continuous rectification is performed, the precipitated solids will accumulate on the tray or the gas-liquid channel of the structured packing of the rectification tower, causing the rectification tower to be blocked. Therefore, there are two traditional methods for recovering solvents containing solid mother liquor. One is to first evaporate all the solvents from the mother liquor by simple evaporation, and then collect the condensate containing solvents and solids and the mother liquor containing solids and solvents, respectively, and then treat the solvents and solids, respectively. The characteristic of this method is that the continuous rectification tower with high recovery efficiency can be used to recover the solvents, and the loss of solvents can be ignored when treating the solid-containing mother liquor. The other method is to use intermittent rectification, which requires more towers and kettles, often more than ten. The two traditional methods have their own advantages and disadvantages, and the common disadvantage is high energy consumption and large equipment investment. There are multiple evaporation and condensation processes, and the consumption of steam and circulating cooling water is large. It is a large energy consumer of the entire product, and the process is discontinuous, requiring operators to continuously operate and switch processing, which greatly consumes manpower. SUMMARY

[0003] Therefore, in view of the problems of high energy consumption, large equipment investment, multiple evaporation and condensation processes, large consumption of steam and circulating cooling water, and discontinuous operation requiring a large amount of manpower in the traditional treatment method, a series connection type rectification recovery device is provided. The series connection type rectification recovery device directly utilizes the heat enthalpy of steam to save energy, combines multiple independent intermittent rectification towers into a continuous rectification tower, and changes the original independent intermittent rectification kettles into multiple distillation kettles in series connection. The rectification tower is set in linkage to ensure that the proportion of steam components entering the rectification tower is basically constant, so that the settings and adjustment parameters of the rectification tower can be basically fixed, saving equipment and improving rectification quality. At the same time, continuous operation can be realized, all concentrated products can be gathered in one discharge kettle, and automatic discharge can be realized, greatly saving operating manpower.

[0004] A series connection type rectification recovery device, comprising a distillation assembly, a rectification tower, a reboiler and a tower top condenser, the distillation assembly comprises a plurality of distillation kettles and liquid inlet pumps, the plurality of distillation kettles are connected in series, the adjacent distillation kettles are respectively connected with the liquid inlet pumps, the bottom of the last distillation kettle is connected with a discharge pipe for discharging, the top of each distillation kettle is connected with the rectification tower through a pipeline, the rectification tower is used for collecting the steam of the distillation assembly and performing fractionation to form a light fraction and a heavy fraction, the reboiler is connected with the bottom of the rectification tower for reboiling the heavy fraction, and the tower top condenser is connected with the top of the rectification tower for condensing the light fraction of the rectification tower.

[0005] In some embodiments, the series connection type rectification recovery device further comprises a discharge pump and a product storage tank, the discharge pump is connected with the discharge pipe, and the product storage tank is connected with the concentrated product discharge pump for collecting the concentrated solid-containing liquid at the bottom of the distillation kettle.

[0006] In some embodiments, the number of the distillation kettles is 5-8.

[0007] In some embodiments, the volume of the distillation kettles is 2m 3 -12m 3 .

[0008] In some embodiments, a liquid level meter and / or an in-kettle material detection sampling port and / or a steam cooling detection sampling port are arranged in each distillation kettle.

[0009] In some embodiments, a control valve is arranged on the pipeline connecting the top of each distillation kettle with the rectification tower.

[0010] In some embodiments, a stirring mechanism is arranged in each distillation kettle, and / or a program-controlled temperature increasing heating device is arranged outside the distillation kettle.

[0011] Another object of the present application is to provide a series connection type rectification recovery method.

[0012] A series connection type rectification recovery method using the series connection type rectification recovery device, comprising the following steps:

[0013] Step 1, the solvent-containing liquid to be treated enters the first distillation kettle for kettle distillation, the concentrated product produced in the first distillation kettle enters the next distillation kettle for kettle distillation, the solid-containing liquid at the bottom of the last distillation kettle is pumped out, and the steam produced by each distillation kettle is combined and then enters the rectification tower; and

[0014] Step 2, the rectification tower fractionates the steam to form a light fraction and a heavy fraction.

[0015] In some embodiments, step 1 specifically includes the following steps: controlling the distillation temperature T1 in the first distillation kettle, feeding the solvent-containing liquid to be treated into the first distillation kettle for kettle distillation, and detecting the vapor solvent content in the first distillation kettle in line sampling. When the vapor solvent content in the first distillation kettle reaches the first vapor solvent preset value or the solvent content in the material in the distillation kettle reaches the first material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the dynamic balance of the liquid phase feed amount, vapor evaporation amount, and liquid phase discharge amount in the first distillation kettle is maintained.

[0016] controlling the distillation temperature T2 in the second distillation kettle, feeding the solid-containing liquid in the kettle bottom of the first distillation kettle into the second distillation kettle for kettle distillation, and detecting the vapor solvent content in the second distillation kettle in line sampling. When the vapor solvent content in the second distillation kettle reaches the second vapor solvent preset value or the solvent content in the material in the distillation kettle reaches the second material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the dynamic balance of the liquid phase feed amount, vapor evaporation amount, and liquid phase discharge amount in the second distillation kettle is maintained.

[0017] By analogy, controlling the distillation temperature Tn in the last distillation kettle, feeding the solid-containing liquid in the kettle bottom of the n-1th distillation kettle into the last distillation kettle for kettle distillation, and detecting the vapor solvent content in the last distillation kettle in line sampling. When the vapor solvent content in the last distillation kettle reaches the n vapor solvent preset value or the solvent content in the material in the distillation kettle reaches the n material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the dynamic balance of the liquid phase feed amount, vapor evaporation amount, and liquid phase discharge amount in the last distillation kettle is maintained.

[0018] In some embodiments, the liquid phase feed speed v1 of the first distillation kettle is v1 = {V1 gas + V2 gas +... + V(n-1) gas + Vn gas + Vn liquid} / t; where V1 gas represents the gas phase discharge amount in the first distillation kettle, and by analogy, Vn gas represents the gas phase discharge amount in the nth distillation kettle, and Vn liquid represents the liquid phase discharge amount of the nth distillation kettle.

[0019] The liquid phase feed speed v2 of the second distillation kettle is v2 = V1 liquid / t, where V1 liquid represents the liquid phase discharge amount of the first distillation kettle.

[0020] The liquid phase feed speed v(n-1) of the n-1th distillation kettle is v(n-1) = V(n-2) liquid / t, where V(n-2) liquid represents the liquid phase discharge amount of the n-2th distillation kettle.

[0021] The liquid phase feed speed vn of the nth distillation kettle is vn = V(n-1) liquid / t, where V(n-1) liquid represents the liquid phase discharge amount of the n-1th distillation kettle.

[0022] The vapor phase evaporation amount of the rectification tower per t hour is V1 gas + V2 gas +... + Vn gas, and the liquid phase discharge amount of the last distillation kettle is Vn liquid.

[0023] Another object of the present application is to provide an application of the series rectification recovery method.

[0024] An application of the series rectification recovery method in solvent and product recovery in D / L-pantothenyl lactone liquor.

[0025] The series rectification recovery device combines multiple batch rectifications into one continuous rectification, saves equipment, directly feeds the distillation tower with the solvent gasification heat of general distillation, does not need the condensation and reboiling process, saves energy, is linked and set, keeps the gas feeding amount and the component proportion entering the rectification tower basically constant, facilitates rectification setting, and guarantees the quality of rectification. Meanwhile, continuous operation can be realized, all concentrated products are gathered in one discharge kettle, automatic discharge is realized, and operation manpower is greatly saved. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0027] In order to more completely understand the present application and its beneficial effects, the following will be described with reference to the drawings. In the following description, the same reference numerals represent the same parts.

[0028] Figure 1 The series rectification recovery device described in an embodiment of the present application is shown in the schematic diagram.

[0029] Explanation of reference numerals

[0030] 10, series rectification recovery device; 100, distillation kettle; 101, liquid feeding pump; 200, discharge pump; 300, rectification tower; 400, reboiler; 500, tower top condenser; 600, product storage tank. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0032] In the description of the present application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0033] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0034] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0036] It is to be noted that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it is to be understood that when a layer is referred to as being "connected", "coupled", or "adjacent" to another element, it can be directly connected, coupled, or adjacent to the other element, or intervening elements can also be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] In the description of the present application, the plural form is meant to denote two or more, the singular form is meant to denote one, and the singular number is meant to denote not only one but also the same. The meaning of "more than", "less than", "exceeding", etc. is understood to be exclusive of the number itself, and the meaning of "above", "below", "within", etc. is understood to be inclusive of the number itself. If it is described as first, second, etc., it is only for the purpose of distinguishing the technical features and cannot be understood as indicating or implying relative importance or indicating the number of technical features indicated or the order of technical features indicated.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] The embodiment of the present application provides a series type rectification recovery device 10 to solve the problems of large energy consumption, large equipment investment, multiple evaporation and condensation processes, large consumption of steam and circulating cooling water, discontinuous operation and large consumption of manpower in the traditional treatment method. The series type rectification recovery device 10 will be described below with reference to the accompanying drawings.

[0040] The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in Figure 1 The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in Figure 1 The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in The structure diagram of the series type rectification recovery device 10 provided by the embodiment of the present application. The series type rectification recovery device 10 can be used for industrial waste liquid recovery treatment.

[0041] In order to more clearly illustrate the structure of the series type rectification recovery device 10, the series type rectification recovery device 10 will be introduced below in combination with the accompanying drawings.

[0042] The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in Figure 1 The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in Figure 1 The series type rectification recovery device 10 provided by the embodiment of the present application is exemplarily shown in The structure diagram of the series type rectification recovery device 10 provided by the embodiment of the present application. The series type rectification recovery device 10 includes a distillation assembly, a discharge pump 200, a rectification tower 300, a reboiler 400 and a tower top condenser 500.

[0043] The distillation assembly comprises a plurality of distillation kettles 100 and liquid inlet pumps 101. The plurality of distillation kettles 100 are connected in series, and between adjacent distillation kettles 100, a liquid inlet pump 101 is connected respectively. An outlet pump 200 is connected to the last distillation kettle 100 through an outlet pipe for discharging the solid-containing liquid concentrated at the kettle bottom of the distillation kettle 100. The top of each distillation kettle 100 is connected to a rectifying column 300 through a pipe.

[0044] The rectifying column 300 is used to collect the steam of the distillation assembly and fractionate to form light and heavy fractions.

[0045] A reboiler 400 is connected to the bottom of the rectifying column 300 for reboiling the heavy fraction.

[0046] A column top condenser 500 is connected to the top of the rectifying column 300 for condensing the light fraction of the rectifying column 300.

[0047] In some embodiments, the series rectification recovery device 10 further comprises a product storage tank 600. The product storage tank 600 is connected to the outlet pump 200 for collecting the concentrated product pumped out by the outlet pump 200.

[0048] In some embodiments, the number of distillation kettles 100 is 5-8. Preferably, referring to Figure 1 shown in the figure, Figure 1 the number of distillation kettles 100 is 5.

[0049] In some embodiments, the volume of the distillation kettle 100 is 2m 3 -12m 3 The volume of the distillation kettle 100 can be set according to actual needs.

[0050] In some embodiments, a liquid level gauge is arranged in each distillation kettle 100. The liquid level gauge is used to detect the liquid level in the distillation kettle 100.

[0051] In some embodiments, a steam cooling detection sampling port is arranged in each distillation kettle 100 respectively. The steam cooling detection sampling port is used to detect the steam in the kettle of the distillation kettle 100 after sampling, so as to match the switching of the stage temperature rise of each distillation kettle 100.

[0052] In some embodiments, an in-kettle material detection sampling port is arranged in each distillation kettle 100 respectively. The in-kettle material detection sampling port is used to detect the liquid material in the kettle of the distillation kettle 100 after sampling, so as to match the switching of the stage temperature rise of each distillation kettle 100.

[0053] In some embodiments, a control valve is arranged on the pipe connecting the top of each distillation kettle 100 to the rectifying column 300.

[0054] In some embodiments, each distillation kettle 100 is provided with a stirring mechanism. The stirring mechanism is used to stir the liquid in the distillation kettle 100.

[0055] In some embodiments, each distillation kettle 100 is provided with a program-controlled temperature rising heating device. The program-controlled temperature rising heating device is used to accurately control the temperature of the different stages in the distillation kettle 100, so that the vapor components are more uniform.

[0056] Another object of the present application is to provide a series distillation recovery method.

[0057] A series distillation recovery method using a series distillation recovery device 10, comprising the following steps:

[0058] Step 1, the solvent-containing liquid to be treated enters the first distillation kettle 100 for kettle distillation, the concentrated product produced in the first distillation kettle 100 enters the next distillation kettle 100 for kettle distillation, and the solid-containing liquid at the bottom of the last distillation kettle 100 is pumped out by the discharge pump 200, and the vapor produced by each distillation kettle 100 enters the rectification column 300; and

[0059] Step 2, the rectification column 300 fractionates the vapor to form light and heavy fractions.

[0060] In some embodiments, step 1 specifically comprises the following steps: controlling the distillation temperature T1 in the first distillation kettle 100, the solvent-containing liquid to be treated enters the first distillation kettle 100 for kettle distillation, online sampling detects that the solvent content of the vapor distilled in the first distillation kettle 100 is the first vapor solvent preset value or the solvent content of the material in the distillation kettle is the first material solvent preset value, and constant liquid level discharge is started after reaching the preset liquid level, keeping the dynamic balance of the liquid phase feed amount, vapor evaporation amount, and liquid phase discharge amount of the first distillation kettle 100;

[0061] controlling the distillation temperature T2 in the second distillation kettle 100, the solid-containing liquid at the bottom of the first distillation kettle 100 enters the second distillation kettle 100 for kettle distillation, online sampling detects that the solvent content of the vapor distilled in the second distillation kettle 100 is the second vapor solvent preset value or the solvent content of the material in the distillation kettle is the second material solvent preset value, and constant liquid level discharge is started after reaching the preset liquid level, keeping the dynamic balance of the liquid phase feed amount, vapor evaporation amount, and liquid phase discharge amount of the second distillation kettle 100;

[0062] Similarly, the distillation temperature Tn in the last distillation kettle 100 is controlled, the solid-containing liquid at the bottom of the n-1th distillation kettle 100 is fed into the last distillation kettle 100 for kettle distillation, and online sampling detection is performed until the vapor solvent content of the distillation vapor of the last distillation kettle 100 is the n vapor solvent preset value or the material solvent content in the distillation kettle is the n material solvent preset value, and after reaching the preset liquid level, constant liquid level discharge is started, and the dynamic balance of the liquid phase feed amount, the gas phase evaporation amount and the liquid phase discharge amount of the last distillation kettle 100 is maintained.

[0063] In this embodiment, the first distillation kettle 100 is evaporated first, and evaporation and gas phase discharge are performed simultaneously at a fixed speed, the evaporation and concentration liquid level gradually rises, and after reaching the preset liquid level, the first distillation kettle 100 discharges into the next kettle (the second distillation kettle 100). The evaporation capacity and feed speed of the series rectification recovery device 10 need to be theoretically calculated in advance according to the actual situation of the material liquid to be evaporated, the actual liquid level in the first distillation kettle 100 is reached, and the feed is maintained while the constant liquid level discharge is maintained. At this time, the solvent concentration in the kettle will not deviate too much, and if there is a slight concentration deviation, the evaporation capacity can be adjusted by adjusting the amount of heating steam, while the actual feed speed remains basically unchanged. The liquid level in the first distillation kettle 100 reaches the set value, and the discharge into the next kettle is started. The solvent concentration of the liquid phase to be discharged in the kettle is detected online, and if the concentration is too high, the amount of heating steam is increased, and if the concentration is too low, the amount of heating steam is decreased. As long as the liquid phase feed speed of the first distillation kettle 100 is fixed and the liquid phase discharge concentration reaches the preset value, the gas phase evaporation amount is fixed, the heating steam is also fixed, and continuous and stable operation is achieved. After that, there is no need to operate and adjust the parameters. The liquid phase feed of the second distillation kettle 100 comes from the liquid phase discharge of the previous distillation kettle 100. As described above, after the parameters of the first distillation kettle 100 are stabilized, the liquid phase discharge of the first distillation kettle 100 is also the liquid phase feed of the second distillation kettle 100. After the parameters of the second distillation kettle 100 are stabilized, there will be no other sources of feed. The second distillation kettle 100 is operated in the same way as the first distillation kettle 100. The solvent concentration of the liquid phase to be discharged is detected by sampling, and if the concentration is too high, the amount of heating steam is increased, and if the concentration is too low, the amount of heating steam is decreased, so as to achieve a stable evaporation amount and a stable liquid phase concentration. Finally, after reaching the preset liquid level, the discharge is started. The whole process is consistent with the operation process of the first distillation kettle 100. Similarly, the third distillation kettle 100, the fourth distillation kettle 100 and the fifth distillation kettle 100 are operated.

[0064] In some embodiments, after the system is balanced and stabilized, the liquid phase feed speed v1 of the first distillation kettle 100 is v1 = {V1 gas + V2 gas +... + V(n-1) gas + Vn gas + Vn liquid} / t; wherein V1 gas represents the gas phase discharge amount in the first distillation kettle 100, and similarly, Vn gas represents the gas phase discharge amount in the nth distillation kettle 100, and Vn liquid represents the liquid phase discharge amount of the nth distillation kettle 100.

[0065] The liquid phase feeding speed v2 of the second distillation kettle 100 is V1 liquid / t, wherein V1 liquid represents the liquid phase discharging amount of the first distillation kettle 100; it should be noted that the liquid phase feeding speed v2 of the second distillation kettle 100 can also be represented as v2={V2 gas+...+V(n-1) gas+Vn gas+Vn liquid} / t.

[0066] The liquid phase feeding speed v(n-1) of the n-1th distillation kettle 100 is V(n-2) liquid / t, wherein V(n-2) liquid represents the liquid phase discharging amount of the n-2th distillation kettle 100; it should be noted that the liquid phase feeding speed v3 of the third distillation kettle 100 can also be represented as v3={V3 gas+...+V(n-1) gas+Vn gas+Vn liquid} / t.

[0067] The liquid phase feeding speed vn of the nth distillation kettle 100 is V(n-1) liquid / t, wherein V(n-1) liquid represents the liquid phase discharging amount of the n-1th distillation kettle 100; it should be noted that the liquid phase feeding speed vn of the nth distillation kettle 100 can also be represented as vn={Vn gas+Vn liquid} / t.

[0068] The gas phase evaporation amount entering the rectification tower 300 per t hour is V1 gas+V2 gas+...+Vn gas, and the liquid phase discharging amount of the last distillation kettle 100 is Vn liquid.

[0069] Another embodiment of the present application also provides an application of the series connection type rectification recovery method.

[0070] An application of a series connection type rectification recovery method in solvent recovery in D / L-pantothenyl lactone mother liquor.

[0071] The series connection type rectification recovery device 10 combines multiple intermittent rectifications into one continuous rectification, saves equipment, directly feeds the distillation tower 300 by using the solvent gasification heat of general distillation, does not need the condensation and reboiling process, saves energy, is linked and set, keeps the gas feeding amount and the component proportion entering the distillation tower 300 basically constant, facilitates rectification setting, and guarantees the quality of rectification. Meanwhile, continuous operation can be realized, all concentrated products are gathered in one discharging kettle, automatic discharging is realized, and operation manpower is greatly saved.

[0072] Embodiment 1

[0073] The embodiment provides a series connection type rectification recovery device 10.

[0074] The series connection type rectification recovery device 10 of the embodiment includes a distillation assembly, a discharging pump 200, a rectification tower 300, a reboiler 400, a tower top condenser 500, and a product storage tank 600.

[0075] The distillation assembly comprises five distillation kettles 100 and four liquid inlet pumps 101. The volume of the distillation kettle 100 is 5m 3 A liquid level meter and a kettle material detection sampling port, and a steam cooling detection sampling port are arranged in each distillation kettle 100. A stirring mechanism is arranged in each distillation kettle 100. The five distillation kettles 100 are connected in series, and a program-controlled temperature increasing heating device is arranged outside each distillation kettle 100. The adjacent distillation kettles 100 are connected by the liquid inlet pump 101.

[0076] The discharge pump 200 is connected to the last distillation kettle 100 for discharging the kettle bottom solid-containing liquid. The product storage tank 600 is connected to the discharge pump 200 for collecting the kettle bottom solid-containing liquid pumped out by the discharge pump 200. The top of each of the five distillation kettles 100 is connected to the rectifying column 300. The pipe connecting the top of each of the distillation kettles 100 to the rectifying column 300 is provided with a control valve.

[0077] The rectifying column 300 is used to collect the steam of the distillation assembly and perform fractional distillation to form light and heavy fractions.

[0078] The reboiler 400 is connected to the bottom of the rectifying column 300 for reboiling the heavy fraction.

[0079] The overhead condenser 500 is connected to the top of the rectifying column 300 for condensing the light fraction of the rectifying column 300.

[0080] Example 2

[0081] The present embodiment provides a series rectification recovery method.

[0082] The series rectification recovery method of the present embodiment uses the series rectification recovery device 10 of the example, comprising the following steps:

[0083] Step 1, the solvent-containing liquid to be treated enters the first distillation kettle 100 for kettle distillation, the concentrated product produced in the first distillation kettle 100 enters the next distillation kettle 100 for kettle distillation, and the kettle bottom solid-containing liquid of the last distillation kettle 100 is pumped out, and the steam produced in each distillation kettle 100 enters the rectifying column 300.

[0084] Specifically, the distillation temperature T1 in the first distillation kettle 100 is controlled, the solvent-containing liquid to be treated enters the first distillation kettle 100 for kettle distillation, and when the solvent content of the material in the first distillation kettle 100 is detected by online sampling and is the first material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the liquid phase feed amount, vaporization amount of the gas phase, and liquid phase discharge amount of the first distillation kettle 100 are kept in dynamic balance;

[0085] The distillation temperature T2 in the second distillation kettle 100 is controlled, the solid-containing liquid at the kettle bottom of the first distillation kettle 100 is pumped into the second distillation kettle 100 by the liquid inlet pump 101 for kettle distillation, and when the material solvent content in the second distillation kettle 100 is detected by online sampling to be the second material solvent preset value, constant liquid level discharging is started after the preset liquid level is reached, and the dynamic balance of the liquid phase feeding amount, the gas phase evaporation amount and the liquid phase discharging amount of the second distillation kettle 100 is maintained.

[0086] By analogy, the distillation temperature T5 in the fifth distillation kettle 100 is controlled, the solid-containing liquid at the kettle bottom of the fourth distillation kettle 100 is pumped into the fifth distillation kettle 100 by the liquid inlet pump 101 for kettle distillation, and when the material solvent content in the fifth distillation kettle 100 is detected by online sampling to be the fifth material solvent preset value, constant liquid level discharging is started after the preset liquid level is reached, and the dynamic balance of the liquid phase feeding amount, the gas phase evaporation amount and the liquid phase discharging amount of the fifth distillation kettle 100 is maintained.

[0087] After the system is stabilized and balanced, the liquid phase feeding speed v1 of the first distillation kettle 100 is (V1 gas+V2 gas+...+V5 gas+V5 liquid) / t; wherein V1 gas represents the gas phase discharging amount in the first distillation kettle 100, V5 gas represents the gas phase discharging amount in the fifth distillation kettle 100, and V5 liquid represents the liquid phase discharging amount in the fifth distillation kettle 100.

[0088] The liquid phase feeding speed v2 of the second distillation kettle 100 is (V2 gas+...+V5 gas+V5 liquid) / t;

[0089] The liquid phase feeding speed v3 of the third distillation kettle 100 is (V3 gas+V4 gas+V5 gas+V5 liquid) / t;

[0090] The liquid phase feeding speed v4 of the fourth distillation kettle 100 is (V4 gas+V5 gas+V5 liquid) / t;

[0091] The liquid phase feeding speed v5 of the fifth distillation kettle 100 is (V5 gas+V5 liquid) / t;

[0092] Every t hours, the gas phase evaporation amount entering the rectification tower 300 is V1 gas+V2 gas+...+V5 gas, and the liquid phase discharging amount of the last (fifth) distillation kettle 100 is V5 liquid.

[0093] Step 2, when the liquid phase is discharged from the last distillation kettle 100, the solid-containing liquid at the kettle bottom is pumped out, and when the gas phase is discharged from the distillation kettle 100, the generated steam enters the rectification tower 300.

[0094] Step 3, the rectification tower 300 performs fractional distillation on the steam to form light and heavy fractions.

[0095] Example 3

[0096] The D / L-pantothenyl lactone process wastewater was treated by the series distillation recovery method of the present embodiment. The process wastewater was extracted with ethyl acetate to obtain a recovery extract liquid, and the recovery extract liquid was treated by the series distillation recovery method of the present embodiment.

[0097] The recovery extract liquid was fed into the first distillation still 100 (volume 5 m 3 ) at a liquid phase feeding speed v1=1000 kg / h. The components and approximate contents of the recovery extract liquid were D / L-pantothenyl lactone 5%, water 5%, and ethyl acetate 90%. The data after reaching a stable equilibrium were as follows:

[0098] The feeding speed v1 of the first distillation still 100 was 1000 kg / h, the gas phase discharge speed V1gas was 230 kg / h, the liquid phase discharge speed V1liquid was 770 kg / h, and the distillation temperature T1 in the first distillation still 100 was controlled at 82°C.

[0099] The feeding speed v2 of the second distillation still 100 was 770 kg / h, the gas phase discharge speed V2gas was 210 kg / h, the liquid phase discharge speed V2liquid was 560 kg / h, and the distillation temperature T2 in the second distillation still 100 was controlled at 85°C.

[0100] The feeding speed v3 of the third distillation still 100 was 560 kg / h, the gas phase discharge speed V3gas was 200 kg / h, the liquid phase discharge speed V3liquid was 360 kg / h, and the distillation temperature T3 in the third distillation still 100 was controlled at 88°C.

[0101] The feeding speed v1 of the fourth distillation still 100 was 360 kg / h, the gas phase discharge speed V4gas was 150 kg / h, the liquid phase discharge speed V4liquid was 210 kg / h, and the distillation temperature T4 in the fourth distillation still 100 was controlled at 93°C.

[0102] The feeding speed v5 of the fifth distillation still 100 was 210 kg / h, the gas phase discharge speed V5gas was 140 kg / h, the liquid phase discharge speed V5liquid was 70 kg / h, and the distillation temperature T5 in the fifth distillation still 100 was controlled at 101°C.

[0103] In the example 3, the initial D / L-pantothenyl lactone solution contains 5% lactone, 90% solvent ethyl acetate, and 5% water. Five distillation kettles 100 are provided in the example, and the output concentrations of the liquid-phase solvent ethyl acetate in the kettles are set to be 65%, 45%, 25%, 10%, and 0.05% respectively (the data can be adjusted according to the actual equipment conditions). Even if the ethyl acetate concentrations in the last two kettles are very low, the lactone will not be precipitated in solid state due to the presence of water, and the lactone is in liquid solution, which can be pumped out by the liquid feeding pump 101.

[0104] Therefore, the gas-phase output speed, i.e., the feeding speed of the rectification tower 300, is v feed = 930 kg / h (V1 gas + V2 gas + V3 gas + V4 gas + V5 gas, the component ethyl acetate is 900 kg / h, and the water is 30 kg / h, with a water content of 3.2%).

[0105] It is detected and calculated that the light distillate output from the rectification tower 300 is v light = 899 kg / h (the component ethyl acetate is 899 kg / h, with a content of >99.8%), and the heavy distillate output from the rectification tower 300 is v heavy = 29.9 kg / h (the component water is 29.9 kg / h, with a content of >99.9%).

[0106] In the above examples, the description of each example focuses on different aspects, and the parts not described in detail in a certain example can be referred to the relevant description of other examples.

[0107] The technical features of the above examples can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above examples are not described, but as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0108] The above examples only express several embodiments of the present disclosure, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present patent. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which are within the scope of the present disclosure. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. A series rectifying recovery apparatus, characterized by, The distillation assembly, the rectifying column, the reboiler and the overhead condenser, the distillation assembly comprises several distillation kettles and liquid inlet pumps, the distillation kettles are connected in series, the liquid inlet pumps are connected between adjacent distillation kettles respectively, the bottom of the last distillation kettle is connected with a discharge pipe for discharging, the top of each distillation kettle is connected with the rectifying column through a pipeline, the steam produced by each distillation kettle is combined and then enters the rectifying column, a program-controlled temperature heating device is arranged outside the distillation kettles, the program-controlled temperature heating device is used for controlling the temperature of different stages in the distillation kettles, keeping the gas amount and component proportion entering the rectifying column basically constant, the rectifying column is used for collecting the steam of the distillation assembly and performing fractionation to form light fraction and heavy fraction, the reboiler is connected with the bottom of the rectifying column for reboiling the heavy fraction, and the overhead condenser is connected with the top of the rectifying column for condensing the light fraction of the rectifying column.

2. The apparatus according to claim 1, wherein The series rectification recovery device further comprises a discharge pump and a product storage tank, the discharge pump is connected with the discharge pipe, and the product storage tank is connected with the discharge pump for collecting the concentrated solid-containing liquid at the bottom of the distillation kettles.

3. The apparatus of claim 1, wherein, The number of the distillation kettles is 5-8.

4. The series-type rectifying recovery apparatus according to any one of claims 1 to 3, characterized by The volume of the distillation kettle is 2 m 3 ~ 12 m 3 .

5. The series-type rectifying recovery apparatus according to any one of claims 1 to 3, characterized by A liquid level meter and / or a material detection sampling port in each distillation kettle and / or a steam cooling detection sampling port are arranged.

6. The series-type rectifying recovery apparatus according to any one of claims 1 to 3, characterized by A control valve is arranged on the pipeline connecting the top of each distillation kettle with the rectifying column. And / or, a stirring mechanism is arranged in each distillation kettle.

7. A series rectification recovery process characterized by, The series rectification recovery device is used, and the steps are as follows: Step 1: the solvent-containing liquid to be treated enters the first distillation kettle for kettle distillation, the concentrated product produced in the first distillation kettle enters the next distillation kettle for kettle distillation, the solid-containing liquid at the bottom of the last distillation kettle is pumped out, the steam produced by each distillation kettle is combined and then enters the rectifying column, the program-controlled temperature heating device is used for program heating of each distillation kettle, the temperature of different stages in the distillation kettles is controlled, and the gas amount and component proportion entering the rectifying column are kept basically constant; and Step 2: the rectifying column performs fractionation on the steam to form light fraction and heavy fraction.

8. The series rectification recovery method according to claim 7, wherein Step 1 specifically comprises the following steps: controlling the distillation temperature T1 of the first distillation kettle, the solvent-containing liquid to be treated enters the first distillation kettle for kettle distillation, the solvent content of the steam distilled in the first distillation kettle is detected online, when the solvent content of the steam is a first steam solvent preset value or the solvent content of the material in the kettle is a first material solvent preset value, constant liquid level discharging is started after reaching a preset liquid level, and the liquid phase feeding amount, the gas phase evaporation amount and the liquid phase discharging amount of the first distillation kettle are kept in dynamic balance. controlling the distillation temperature T2 in the second distillation kettle, the solid-containing liquid at the bottom of the first distillation kettle is fed into the second distillation kettle for kettle distillation, and when the vapor solvent content in the second distillation kettle is detected to be the second vapor solvent preset value or the material solvent content in the kettle is detected to be the second material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the liquid phase feed amount, the gas phase evaporation amount, and the liquid phase discharge amount of the second distillation kettle are kept in dynamic balance; By analogy, the distillation temperature Tn in the last distillation kettle is controlled, the solid-containing liquid at the bottom of the (n-1)th distillation kettle is fed into the last distillation kettle for kettle distillation, and when the vapor solvent content in the last distillation kettle is detected to be the nth vapor solvent preset value or the material solvent content in the kettle is detected to be the nth material solvent preset value, constant liquid level discharge is started after reaching the preset liquid level, and the liquid phase feed amount, the gas phase evaporation amount, and the liquid phase discharge amount of the last distillation kettle are kept in dynamic balance.

9. The series distillation recovery method according to claim 8, characterized in that, the liquid phase feed speed v1 of the first distillation kettle is V1 gas + V2 gas +... + V(n-1) gas + Vn gas + Vn liquid / t; wherein V1 gas represents the gas phase discharge amount in the first distillation kettle, and by analogy, Vn gas represents the gas phase discharge amount in the nth distillation kettle, and Vn liquid represents the liquid phase discharge amount of the nth distillation kettle; the liquid phase feed speed v2 of the second distillation kettle is V1 liquid / t, wherein V1 liquid represents the liquid phase discharge amount of the first distillation kettle; the liquid phase feed speed v(n-1) of the (n-1)th distillation kettle is V(n-2) liquid / t, wherein V(n-2) liquid represents the liquid phase discharge amount of the (n-2)th distillation kettle; the liquid phase feed speed vn of the nth distillation kettle is V(n-1) liquid / t, wherein V(n-1) liquid represents the liquid phase discharge amount of the (n-1)th distillation kettle; every t hours, the gas phase evaporation amount into the distillation tower is V1 gas + V2 gas +... + Vn gas, and the liquid phase discharge amount of the last distillation kettle is Vn liquid.

10. Application of the series distillation recovery method according to any one of claims 7-9 in solvent and product recovery in D / L-pantothenyl lactate mother liquor.

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