Lifting film evaporator discharging device and using method

Abstract

The invention discloses a lifting film evaporator discharging device and a using method. The lifting film evaporator discharging device comprises a lifting film evaporator, a separator bottom pipe, a metering pump, an intermediate storage tank, a gravity sensing device, a receiving tank, a high-precision diaphragm pump, a backflow pipeline and a bypass valve. The specific operation is as follows: the concentrated solution primarily treated by the climbing film evaporator is conveyed into the intermediate storage tank through the pneumatic metering pump, after a certain volume of the concentrated solution is pumped into the metering pump, the weight of the liquid in the intermediate storage tank is determined by the gravity sensing device, and after the weight meets a set value, the discharge valve is opened, so that the concentrated solution flows out into the receiving tank through gravity; when the weight does not meet the set value, the bypass valve and the high-precision diaphragm pump are opened, and the concentrated solution which does not meet the requirement is pumped into the climbing film evaporator through the backflow pipeline to further remove the solvent. The device is easy to install, low in cost and capable of being widely used; the automation degree is high, and manpower resources are saved; the product stability is improved.

Description

Technical Field

[0001] This invention relates to the field of rising film evaporator technology, specifically to a rising film evaporator discharge device and its usage method. Background Technology

[0002] As a single-pass liquid film evaporator, the core workflow of a rising film evaporator is as follows: The feed liquid (mainly composed of solvent and target product) enters the equipment from the bottom of the heating tube and undergoes a vaporization reaction under the action of heat energy within the heating tube. The generated steam forms a high-speed upward airflow within the tube. Driven by this airflow, the feed liquid rises synchronously along the wall of the heating tube in a film-like form, continuously completing the evaporation process during the ascent. Finally, the vapor-liquid mixture enters the separator for gas-liquid separation: the concentrated liquid containing the target product is discharged from the bottom of the separator, while the solvent vapor is exported from the top of the separator, condensed, and then stored in a dedicated storage tank, thereby achieving the goal of material concentration.

[0003] In actual industrial production, the performance of rising film evaporators is easily affected by multiple factors, including fluctuations in feed temperature, unstable vacuum levels at the production site, and changes in other process conditions. These factors directly lead to generally high solvent content in the concentrate after treatment by the rising film evaporator, especially under low-temperature conditions where the difference in physical properties between the solvent and the product narrows, making it difficult for existing detection methods to accurately determine the actual solvent content in the concentrate. This problem not only affects the quality stability of the concentrate but also has a serious adverse impact on the control of process parameters, reaction efficiency, and final product quality in subsequent reaction processes, becoming a key technical bottleneck in industrial production. Summary of the Invention

[0004] Based on the above-mentioned technical problems, the present invention proposes a rising film evaporator discharge device to solve the problem of poor product quality stability.

[0005] To address the aforementioned technical problems, one objective of this invention is to provide a discharge device for a rising film evaporator, comprising: The reaction apparatus consists of a rising film evaporator 1, a separator bottom pipe 2, a thermometer 3, a metering pump 4, an intermediate storage tank 5, an induction device 6, a receiving tank 7, a reflux device 8, a reflux pipeline 9, and a bypass valve 10. The inlet of the separator bottom pipe (2) is connected to the rising film evaporator (1); The outlet of the separator bottom pipe (2) is connected to the intermediate storage tank (5), and a metering pump (4) is installed in the middle to provide power to pump the concentrated liquid collected in the separator bottom pipe into the intermediate storage tank. A sensing device (6) is installed at the bottom of the intermediate storage tank (5). The bottom of the sensing device (6) is provided with a receiving tank (7), and the bypass of the gravity sensing device is provided with a bypass valve (10), which is connected to the return device (8) through a pipeline. The reflux device (8) provides power to connect the recovered liquid to the rising film evaporator (1) through the reflux pipe (9).

[0006] Furthermore, the reflux device uses a high-precision diaphragm pump.

[0007] Furthermore, the sensing device is a gravity sensor, enabling automated threshold detection.

[0008] Furthermore, the sensing device is an online refractometer or a differential pressure density meter to achieve automated threshold detection.

[0009] Furthermore, the device is equipped with a thermometer 3 in the intermediate storage tank 5, which is mainly used to measure the temperature inside the storage tank and adjust the gravity parameters according to the formula.

[0010] Based on the same concept, the present invention also proposes a process method for a rising film evaporator discharge device, the specific steps of which are as follows: S1: The feed liquid undergoes a vaporization reaction in the rising film evaporator 1, and the generated steam forms a high-speed upward airflow in the tube and evaporates from the top. The solvent is collected and recovered by condensation, and the concentrated liquid accumulates in the bottom tube 2 of the separator. S2: After the solvent is removed, a certain volume of concentrated liquid is pumped into the intermediate storage tank 5 by metering pump 4. S3: After the metering pump 4 pumps in a certain volume of concentrate, the gravity sensing device 6 determines the weight of the liquid in the intermediate storage tank 5. Once the weight meets the set value, the discharge valve is opened, allowing the concentrate to flow out into the receiving tank 7 by gravity. S4: When the weight does not meet the set value, open the bypass valve 10 and the high-precision diaphragm pump 8, and pump the unqualified concentrate into the rising film evaporator 1 through the reflux pipe 9 to repeat the above steps.

[0011] Furthermore, the intermediate storage tank 5 of S2 is equipped with a thermometer 3, and the gravity parameters are adjusted according to the formula to measure the temperature inside the storage tank.

[0012] The above-described technical solutions of the present invention have at least one or more of the following technical effects: the present invention is simple to install, has low device cost, and can be widely used; the equipment has low maintenance cost and is easy to replace; it has a high degree of automation, saving human resources; and it improves product stability. Attached Figure Description

[0013] Figure 1 Schematic diagram of the discharge device of the rising film evaporator: Among them: 1-Rising film evaporator, 2-Separator bottom pipe, 3-Thermometer, 4-Metering pump, 5-Intermediate storage tank, 6-Gravity sensor, 7-Receiving tank, 8-High-precision diaphragm pump, 9-Recirculation pipe, 10-Bypass valve. Detailed Implementation

[0014] This invention specifically modifies the discharge device of a rising film evaporator. The modified device consists of two core modules: a sensing device and a reflux device. The sensing device uses a gravity sensor, and the reflux device uses a high-precision diaphragm pump. The core design basis of this modification scheme is the density difference between the solvent and the target product (the density of the target product involved in this invention is significantly greater than the solvent density). Based on this characteristic, the quality of the concentrate of the same volume will vary significantly depending on the solvent content.

[0015] This invention transforms the density difference between solvent and product into a quantifiable quality inspection indicator. By leveraging the physical characteristic of "different masses per volume," it directly correlates the solvent content in the concentrate (quality meets standards, meaning the solvent content is qualified), enabling precise and real-time assessment of the concentrate's quality. This invention differs from the single discharge process of traditional rising-film evaporators by constructing an integrated closed-loop discharge system consisting of an intermediate tank, a gravity sensor, and a diaphragm pump. The intermediate tank, acting as a "detection and storage unit," receives the initial concentrate and provides a stable detection environment. The gravity sensor, as the "core of quality judgment," pre-sets process parameters to achieve automated threshold detection. The diaphragm pump and bypass valve form a "reflux execution unit," ensuring that substandard concentrate is accurately returned to the evaporator for reprocessing. These three components work together to form a closed loop of "detection-judgment-reflux-re-detection," continuously outputting qualified concentrate without manual intervention, significantly improving production automation and product quality stability.

[0016] Balancing practicality and flexibility: The process parameters of the gravity sensing device can be flexibly calibrated according to the density differences of different materials, and the diaphragm pump selection can also be adapted to materials of different viscosities, providing a foundation for cross-material type applications and avoiding the limitation of "one material, one device". This invention features fully automated control, reducing human error and adapting to large-scale continuous production; "A method for determining solvent content by detecting the mass of a fixed volume of concentrated liquid based on the density difference between solvent and product, and returning substandard concentrated liquid to a rising film evaporator for reprocessing."

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments obtained. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0018] The technical solution of this invention is shown in the figure. The reaction device consists of 1. a rising film evaporator; 2. a separator bottom pipe; 3. a thermometer; 4. a metering pump; 5. an intermediate storage tank; 6. a gravity sensor; 7. a receiving tank; 8. a high-precision diaphragm pump; 9. a reflux pipe; and 10. a bypass valve.

[0019] The structure of the device is shown in the figure. The feed liquid undergoes a vaporization reaction in the rising film evaporator 1. The generated steam forms a high-speed upward airflow in the tube and evaporates from the top. Subsequently, the solvent is collected and recovered by condensation. The concentrated liquid accumulates in the bottom tube 2 of the separator. After the solvent is removed, a certain volume of concentrated liquid is pumped into the intermediate storage tank 5 by the metering pump 4. The thermometer 3 is mainly used to measure the temperature inside the storage tank and adjust the gravity parameters according to the formula.

[0020] After the metering pump pumps in a certain volume of concentrate, the gravity sensor 6 determines the weight of the liquid in the intermediate storage tank 5. Once the weight meets the set value, the discharge valve is opened, allowing the concentrate to flow out to the receiving tank 7 by gravity. If the weight does not meet the set value, the bypass valve 10 and the high-precision diaphragm pump 8 are opened, and the concentrate that does not meet the requirements is pumped into the rising film evaporator 1 through the return pipe 9 for further solvent removal.

[0021] The high-precision diaphragm pump 8 is designed to achieve high-precision metering and safe transport of fluids, with metering errors controlled within 1%. By completely isolating the transported liquid from the drive mechanism through a diaphragm, it possesses leak-free characteristics. This feature enables the safe transport of highly toxic, highly corrosive, volatile, or expensive special media.

[0022] Meanwhile, the diaphragm pump possesses excellent self-priming capability, withstands high temperature and high pressure conditions, continuously delivers reaction materials, can adapt to various complex operating conditions, and is compatible with automation. The control system used in this invention is a DCS control system, which can be adapted to achieve automated control of the diaphragm pump, reducing manual intervention. In addition, PLC and other automation systems can also control the diaphragm pump.

[0023] The specific workflow is as follows: The concentrate, after preliminary treatment by the rising film evaporator, is transported to the intermediate storage tank by a pneumatic metering pump; The bottom of the storage tank is equipped with a pre-calibrated gravity sensor (the device has been pre-input with mass parameter thresholds that meet the process requirements). Once the concentrate flowing into the storage tank reaches the set volume, the metering pump of the feeding system automatically stops feeding, and the gravity sensor starts quality detection. If the quality of the concentrate meets the preset process parameters (i.e., the solvent content meets the standard), the valve at the bottom of the intermediate tank will automatically open, and the concentrate will flow into the subsequent process storage tank under gravity and enter the next production stage; if the quality of the concentrate does not meet the preset process parameters (i.e., the solvent content is too high), the bypass valve of the intermediate tank will automatically open, and the diaphragm pump will start to pump the substandard concentrate back to the feed end of the rising film evaporator for evaporation and separation again. The above-mentioned testing and reflux process is repeated until the gravity sensor detects that the quality of the concentrate meets the process requirements. Then it is introduced into the subsequent process to ensure that the concentrate that finally enters the next stage always meets the quality standards.

[0024] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A discharge device for a rising film evaporator, characterized in that: The device consists of a rising film evaporator (1), a separator bottom pipe (2), a metering pump (4), an intermediate storage tank (5), a gravity sensor (6), a receiving tank (7), a high-precision diaphragm pump (8), a reflux pipe (9), and a bypass valve (10). The inlet of the separator bottom pipe (2) is connected to the rising film evaporator (1); The outlet of the separator bottom pipe (2) is connected to the intermediate storage tank (5) via a flange, and a metering pump (4) is installed in the middle to provide power to pump the concentrated liquid collected in the separator bottom pipe into the intermediate storage tank. A sensing device (6) is installed at the bottom of the intermediate storage tank (5). The bottom of the sensing device (6) is provided with a receiving tank (7), and the bypass of the gravity sensing device is provided with a bypass valve (10), which is connected to the return device (8) through a pipeline. The reflux device (8) provides power to connect the reflux liquid to the rising film evaporator (1) through the reflux pipe (9).

2. The discharge device for a rising film evaporator according to claim 1, characterized in that: The reflux device uses a high-precision diaphragm pump.

3. The discharge device for a rising film evaporator according to claim 1, characterized in that: The sensing device is a gravity sensor, which enables automated threshold detection.

4. The discharge device for a rising film evaporator according to claim 1, characterized in that: The sensing device is an online refractometer or a differential pressure density meter, which enables automated threshold detection.

5. The discharge device for a rising film evaporator according to claim 1, characterized in that: The device is equipped with a thermometer (3) in the intermediate storage tank (5), which is mainly used to measure the temperature inside the storage tank and adjust the gravity parameters according to the formula.

6. The method of using the discharge device of the rising film evaporator according to any one of claims 1-5, characterized in that, The specific steps are as follows: S1: The feed liquid undergoes a vaporization reaction in the rising film evaporator (1), and the generated steam forms a high-speed rising airflow in the tube and evaporates from the top. The solvent is collected and recovered by condensation, and the concentrated liquid accumulates in the bottom tube (2) of the separator. S2: After the solvent is removed, a certain volume of concentrate is pumped into the intermediate storage tank (5) by metering pump (4); S3: When the metering pump (4) pumps in a certain volume of concentrate, the gravity sensing device (6) determines the weight of the liquid in the intermediate storage tank (5). After the weight meets the set value, the discharge valve is opened, so that the concentrate flows out to the receiving tank (7) by gravity. S4: When the weight does not meet the set value, open the bypass valve (10) and the high-precision diaphragm pump (8) to pump the unqualified concentrate into the rising film evaporator (1) through the reflux pipe (9) and repeat the above steps.

7. The method of using the discharge device of the rising film evaporator according to claim 6, characterized in that: The intermediate storage tank (5) of S2 is equipped with a thermometer (3) to measure the temperature inside the storage tank and adjust the gravity parameters according to the formula.

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