Device for adjusting concentration of hydrofluoric acid with water

Abstract

The device comprises a pure water tank, a first regulating valve, a first flow meter, a mixer, a raw material tank, a second regulating valve, a second flow meter, a middle tank, a third pump, a weighing sensor, a third flow meter and a third regulating valve, an outlet of the pure water tank is connected with an inlet of the mixer through a first pipeline; a first regulating valve and a first flow meter are arranged on the first pipeline; an outlet of the raw material tank is connected with an inlet of the mixer through a second pipeline; a second regulating valve and a second flowmeter are arranged on the second pipeline; an outlet of the mixer is connected with an inlet of a middle tank through a third pipeline, an outlet of the middle tank is connected with an inlet of the mixer through a fourth pipeline, a third pump is arranged on the fourth pipeline, and the middle tank is arranged on a weighing sensor; an outlet of the mixer is connected with a fifth pipeline; and a third flowmeter and a third regulating valve are arranged on the fifth pipeline. By additionally arranging the middle tank, more uniform acid concentration distribution can be realized.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, and in particular to an apparatus for adjusting the concentration of hydrofluoric acid in water. Background Technology

[0002] In the aqueous acid preparation system, the reaction tank is equipped with an electronic scale. A certain weight of pure water is manually added to the tank, followed by anhydrous hydrofluoric acid. The tank's pump is then activated to circulate the acid and water, neutralizing them and ensuring a more uniform acid concentration. However, neutralizing hydrofluoric acid and pure water solely through the reaction tank is not very effective, affecting subsequent processes and product quality stability. Furthermore, the addition of both pure water and anhydrous hydrofluoric acid requires manual operation, increasing the workload and posing certain operational risks. Utility Model Content

[0003] Therefore, there is a need for a device to adjust the concentration of hydrofluoric acid in water. This addresses the problem that existing methods, which only use a reaction tank to neutralize hydrofluoric acid and pure water, do not achieve a significant neutralization effect, affecting subsequent processes or product quality stability. Furthermore, the addition of pure water and anhydrous hydrofluoric acid in this system requires manual operation, which increases the workload of operators and poses certain operational risks.

[0004] To achieve the above objectives, this embodiment provides an apparatus for adjusting the concentration of hydrofluoric acid in water, including a pure water tank, a first regulating valve, a first flow meter, a mixer, a raw material tank, a second regulating valve, a second flow meter, an intermediate tank, a third pump, a weighing sensor, a third flow meter, and a third regulating valve;

[0005] The outlet of the pure water tank is connected to the inlet of the mixer through a first pipe, and the first pipe is equipped with the first regulating valve and the first flow meter;

[0006] The outlet of the raw material tank is connected to the inlet of the mixer through a second pipe, and the second pipe is equipped with a second regulating valve and a second flow meter;

[0007] The outlet of the mixer is connected to the inlet of the intermediate tank through a third pipe, and the outlet of the intermediate tank is connected to the inlet of the mixer through a fourth pipe. The third pump is installed on the fourth pipe, and the intermediate tank is installed on the weighing sensor.

[0008] The outlet of the mixer is connected to a fifth pipe, and the fifth pipe is equipped with a third flow meter and a third regulating valve.

[0009] Furthermore, it also includes a condenser, which is provided on the third pipe and / or the fifth pipe.

[0010] Furthermore, the third pipe and the fifth pipe are connected to form a main pipe and two branch pipes, namely the first branch pipe and the second branch pipe. The main pipe is connected to the outlet of the mixer and the condenser is provided on the main pipe. The first branch pipe is connected to the inlet of the intermediate tank and the second branch pipe is provided with a third flow meter and the third regulating valve.

[0011] Furthermore, it also includes a first pump, which is disposed on the first pipeline; and / or:

[0012] It also includes a second pump, which is installed on the second pipeline.

[0013] Furthermore, the first pump is a pure water pump, and the second pump is a diaphragm pump.

[0014] Furthermore, it also includes:

[0015] The first pneumatic shut-off valve is located on the first pipeline.

[0016] Furthermore, it also includes:

[0017] The second pneumatic shut-off valve is located on the second pipeline.

[0018] Furthermore, there are multiple weighing sensors.

[0019] Furthermore, it also includes:

[0020] A thermometer, the thermometer being disposed in the mixer; and

[0021] The controller, together with the thermometer, the first regulating valve, the second regulating valve, the third pump, and the third regulating valve, controls the first regulating valve, the second regulating valve, the third pump, and the third regulating valve to close after the thermometer detects that the temperature of the mixer exceeds a temperature threshold.

[0022] Furthermore, it also includes:

[0023] A level gauge, wherein the level gauge is disposed in the mixer; and

[0024] The controller is connected to the level gauge, the first regulating valve, the second regulating valve, the third pump, and the third regulating valve. After the level gauge detects that the liquid level in the intermediate tank exceeds the liquid level threshold, the controller controls the first regulating valve, the second regulating valve, the third pump, and the third regulating valve to close.

[0025] The advantages of this application, which differ from existing technologies, are as follows:

[0026] (1) By adding an intermediate tank, a more uniform acid concentration distribution can be achieved. The presence of the intermediate tank allows the acid and water to mix fully, thereby improving the uniformity of acid concentration and reducing the negative impact of uneven concentration.

[0027] (2) The use of a weighing sensor can ensure that the weight of the added acid meets the requirements, thereby improving the accuracy and stability of the preparation.

[0028] (3) By setting multiple flow meters and regulating valves, the flow rates of acid and water can be controlled more precisely to achieve the required acid concentration.

[0029] (4) The device has a high degree of automation. It is automatically controlled to reduce errors from manual operation and improve production efficiency.

[0030] (5) The device has a simple structure, is easy to operate and maintain, and has a low cost and a long service life. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the aqueous acid preparation system described in the background art;

[0032] Figure 2 This is one of the structural schematic diagrams of the apparatus for adjusting the concentration of hydrofluoric acid in water according to this embodiment;

[0033] Figure 3 This is the third schematic diagram of the device for adjusting the concentration of hydrofluoric acid in this embodiment;

[0034] Figure 4 This is the fourth schematic diagram of the device for adjusting the concentration of hydrofluoric acid in this embodiment;

[0035] Figure 5 This is a schematic diagram showing the flow direction of the solution in the device of this embodiment.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Pure water tank;

[0038] 2. First pump;

[0039] 3. First pneumatic shut-off valve;

[0040] 4. First flow meter;

[0041] 5. First regulating valve;

[0042] 6. Raw material tank;

[0043] 7. Second pump;

[0044] 8. Second pneumatic shut-off valve;

[0045] 9. Second flow meter;

[0046] 10. Second regulating valve;

[0047] 11. Mixer;

[0048] 12. Condenser;

[0049] 13. Third flow meter;

[0050] 14. Third regulating valve;

[0051] 15. The third pump;

[0052] 16. Intermediate groove;

[0053] 17. Weighing sensor;

[0054] 18. First Pipeline;

[0055] 19. Second pipeline;

[0056] 20. The fourth pipeline;

[0057] 21. The fifth pipeline;

[0058] 22. Finished product tank;

[0059] a. Reaction tank. Detailed Implementation

[0060] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following description is provided in conjunction with specific embodiments and accompanying drawings.

[0061] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0062] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0063] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0064] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0065] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0066] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0067] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0068] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0069] Please see Figure 2 This embodiment provides an apparatus for adjusting the concentration of hydrofluoric acid in water, including a pure water tank 1, a first regulating valve 5, a first flow meter 4, a mixer 11, a raw material tank 6, a second regulating valve 10, a second flow meter 9, an intermediate tank 16, a third pump 15, a weighing sensor 17, a third flow meter 13, and a third regulating valve 14.

[0070] The outlet of the pure water tank 1 is connected to the inlet of the mixer 11 through the first pipe 18. The first pipe 18 is equipped with a first regulating valve 5 and a first flow meter 4.

[0071] The outlet of the raw material tank 6 is connected to the inlet of the mixer 11 through the second pipe 19. The second pipe 19 is equipped with a second regulating valve 10 and a second flow meter 9.

[0072] The outlet of mixer 11 is connected to the inlet of intermediate tank 16 through a third pipe, and the outlet of intermediate tank 16 is connected to the inlet of mixer 11 through a fourth pipe 20. A third pump 15 is provided on the fourth pipe 20, and intermediate tank 16 is provided on the weighing sensor 17.

[0073] The outlet of mixer 11 is connected to the fifth pipe 21, and the fifth pipe 21 is equipped with a third flow meter 13 and a third regulating valve 14.

[0074] The working process for this application is as follows:

[0075] (1) In the initial state, the pure water tank 1 contains a certain amount of pure water, and the raw material tank 6 contains a certain amount of anhydrous hydrofluoric acid.

[0076] (2) Open the first regulating valve 5 and the second regulating valve 10, and pure water and anhydrous hydrofluoric acid enter the mixer 11 through the first pipe 18 and the second pipe 19 respectively.

[0077] (3) In the mixer 11, pure water and anhydrous hydrofluoric acid are mixed to form a hydrofluoric acid solution of a certain concentration.

[0078] (4) Aqueous hydrofluoric acid solution enters intermediate tank 16 from the outlet of mixer 11 through the third pipe.

[0079] (5) The hydrofluoric acid solution in the intermediate tank 16 is weighed by the weighing sensor 17 to ensure that the added weight meets the requirements.

[0080] (6) After weighing, the aqueous hydrofluoric acid solution returns to the mixer 11 from the outlet of the intermediate tank 16 through the fourth pipe 20, and is mixed again with the solution that continues to enter the mixer 11.

[0081] (7) After the solution is mixed evenly, the mixed aqueous hydrofluoric acid solution is discharged from the outlet of mixer 11 through the fifth pipe 21, through the third flow meter 13 and the third regulating valve 14, and finally output to the desired target location.

[0082] The beneficial effects of this application are as follows:

[0083] (1) By adding an intermediate tank 16, a more uniform acid concentration distribution can be achieved. The presence of the intermediate tank 16 allows the acid and water to mix fully, thereby improving the uniformity of acid concentration and reducing the negative impact of uneven concentration.

[0084] (2) The use of the weighing sensor 17 can ensure that the weight of the added acid meets the requirements, thereby improving the accuracy and stability of the preparation.

[0085] (3) By setting multiple flow meters and regulating valves, the flow rates of acid and water can be controlled more precisely to achieve the required acid concentration.

[0086] (4) The device has a high degree of automation. It is automatically controlled to reduce errors from manual operation and improve production efficiency.

[0087] (5) The device has a simple structure, is easy to operate and maintain, and has a low cost and a long service life.

[0088] Please see Figure 1 In this embodiment, the apparatus further includes a condenser 12, which is installed on the third pipe and / or the fifth pipe 21. When the aqueous hydrofluoric acid solution enters the condenser 12 through the third pipe or the fifth pipe 21, the cooling medium (such as cooling water or refrigerant) inside the condenser 12 absorbs the heat of the solution, cooling it. The cooled aqueous hydrofluoric acid solution continues to flow to the next step, such as entering the intermediate tank 16 or being output through the fifth pipe 21. The use of the condenser 12 can effectively reduce the temperature of the aqueous hydrofluoric acid solution, preventing overheating-induced evaporation, leakage, or other safety hazards. The use of the condenser 12 can improve the stability and reliability of the mixing apparatus, ensuring that the aqueous hydrofluoric acid solution maintains a suitable temperature range during the mixing process.

[0089] Please see Figure 1In this embodiment, the third pipe and the fifth pipe 21 are connected to form a main pipe and two branch pipes, namely the first branch pipe and the second branch pipe. The main pipe is connected to the outlet of the mixer 11 and is equipped with a condenser 12. The first branch pipe is connected to the inlet of the intermediate tank 16, and the second branch pipe is equipped with a third flow meter 13 and a third regulating valve 14. In the mixing device, hydrofluoric acid solution enters the main pipe from the outlet of the mixer 11. In the main pipe, the hydrofluoric acid solution is cooled by the condenser 12 to maintain a suitable temperature. The cooled hydrofluoric acid solution enters one of the two branch pipes, which can be selected to enter the first branch pipe or the second branch pipe. If the hydrofluoric acid solution enters the first branch pipe, it will be connected to the inlet of the intermediate tank 16. If the hydrofluoric acid solution enters the second branch pipe, it will be connected to the third flow meter 13 and the third regulating valve 14. The flow rate of the hydrofluoric acid solution in the second branch pipe can be precisely controlled by the third flow meter 13 and the third regulating valve 14.

[0090] Please see Figure 3 In this embodiment, the device further includes a first pump 2, which is mounted on the first pipe 18. The first pump 2, located on the first pipe 18, generates sufficient pressure when activated to push water downstream. Adding the first pump 2 increases the fluidity and flexibility of the dispensing device, ensuring that the solution can be transported and processed according to a predetermined process.

[0091] Please see Figure 3 In this embodiment, the apparatus further includes a second pump 7, which is mounted on the second pipeline 19. The second pump 7, located on the second pipeline 19, generates sufficient pressure when activated to push anhydrous hydrofluoric acid downstream. Adding the second pump 7 increases the flowability and flexibility of the dispensing apparatus, ensuring that the solution can be transferred and processed according to a predetermined process.

[0092] In this embodiment, the first pump 2 is a pure water pump, and the second pump 7 is a diaphragm pump. Using a pure water pump and a diaphragm pump allows for the separate delivery of pure water and anhydrous hydrofluoric acid solution according to different needs, ensuring that they do not contaminate each other. The use of a pure water pump guarantees the quality and purity of the pure water, preventing any impurities from entering the mixing device. The use of a diaphragm pump ensures the safe and reliable delivery of anhydrous hydrofluoric acid solution, preventing leakage and contamination. By using different types of pumps, such as pure water pumps and diaphragm pumps, appropriate pump performance and operating characteristics can be selected according to specific requirements.

[0093] Please see Figure 4In this embodiment, the device further includes a first pneumatic shut-off valve 3, which is disposed on the first pipeline 18. When the system is started, the first pneumatic shut-off valve 3 opens, allowing the fluid to flow along the desired path and delivering the liquid or gas to a designated location. By controlling the open and closed state of the first pneumatic shut-off valve 3, the flow of liquid or gas can be cut off or sent, controlling its delivery to specific equipment or pipelines.

[0094] Please see Figure 4 In this embodiment, the device further includes a second pneumatic shut-off valve 8, which is disposed on the second pipeline 19. When the system is started, the second pneumatic shut-off valve 8 opens, allowing the fluid to flow along the desired path and delivering the liquid or gas to a designated location. By controlling the open and closed state of the second pneumatic shut-off valve 8, the flow of liquid or gas can be cut off or sent, controlling its delivery to specific equipment or pipelines.

[0095] Please see Figure 5 In this embodiment, there are multiple weighing sensors 17. Each weighing sensor 17 determines its weight by measuring the pressure or load applied to the material or product. The weight data measured by the weighing sensor 17 is connected to the controller via the sensor, and the data is transmitted to the controller for processing and analysis. The controller can perform various operations based on the weight data, such as controlling the feeding amount, adjusting the formula ratio, and monitoring material consumption. Each weighing sensor 17 can continue to monitor and measure the weight changes of the material or product to ensure the accuracy and stability of the dispensing device.

[0096] In this embodiment, the device also includes a thermometer and a controller. The thermometer is located in the mixer 11. The controller is connected to the thermometer, the first regulating valve 5, the second regulating valve 10, the third pump 15, and the third regulating valve 14. After the thermometer detects that the temperature of the mixer 11 exceeds the temperature threshold, the controller controls the first regulating valve 5, the second regulating valve 10, the third pump 15, and the third regulating valve 14 to close.

[0097] In this embodiment, the device also includes a level gauge and a controller. The level gauge is located in the mixer 11. The controller is connected to the level gauge, the first regulating valve 5, the second regulating valve 10, the third pump 15, and the third regulating valve 14. After the level gauge detects that the liquid level in the intermediate tank 16 exceeds the liquid level threshold, the controller controls the first regulating valve 5, the second regulating valve 10, the third pump 15, and the third regulating valve 14 to close.

[0098] In this embodiment, the controller is connected to the first regulating valve 5, the first flow meter 4, the second regulating valve 10, the second flow meter 9, the third pump 15, the weighing sensor 17, the third flow meter 13, the third regulating valve 14, the condenser 12, the thermometer, and the level gauge, respectively, to control the operation of these components.

[0099] Please see Figure 5 The principle of the device for automatically adjusting the concentration of hydrofluoric acid in water:

[0100] 1: Set the total output for the controller.

[0101] 2: Set the hourly feed rate on the controller.

[0102] 3: Set the acid concentration ratio (after setting the required acid concentration ratio, the controller will automatically calculate the set amount of acid and water to be fed in).

[0103] 4. Open the first regulating valve of the first pipeline and the second regulating valve of the second pipeline. After the valves are fully opened, the first and second pumps will automatically start. The first and second regulating valves, the first flow meter, and the second flow meter will perform PID control based on the set flow rate calculated by the controller and the regulating valves. The raw materials, acid and water, will enter the mixer and then circulate in the intermediate tank (the mixer is equipped with a thermometer, and the system will shut down if the temperature exceeds the set temperature). The system will then circulate in the third pump (circulation can better neutralize the acid and water, making the acid concentration more uniform), and then release heat through the condenser. The level gauge is set to the upper limit of the discharge. After the intermediate tank reaches a certain level (or weight), the controller will open the third regulating valve. The third regulating valve and the third flow meter will be interlocked for PID control. The discharge setpoint is the feed rate for one hour, thus ensuring the balance of feed and discharge and enabling continuous production of the unit.

[0104] 5: The finished acid from the intermediate tank is pumped to the finished product tank 22 through the fifth pipe. The finished product tank is manually sampled and analyzed to ensure that the concentration meets the standard.

[0105] 1. When adjusting the concentration of aqueous acid, the acid concentration may be too large and not meet the requirements due to the influence of process, pipeline, temperature and pressure. It is recommended to use a mass flow meter with higher accuracy to reduce the error caused by measurement.

[0106] 2: Several online acid concentration analyzers can be added to the finished product tank for online detection.

[0107] This device is equipped with interlocking protection:

[0108] 1. The reactor is equipped with over-temperature protection. The system will shut down when the reaction temperature exceeds the set temperature.

[0109] 2: The intermediate tank is equipped with a level gauge. The interlocking system will stop the tank when the level in the intermediate tank exceeds the level threshold.

[0110] 3: Once the system reaches full production capacity, feeding will stop.

[0111] 4. An external emergency stop button is provided.

[0112] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this utility model. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this utility model, or equivalent structural or procedural transformations made using the content of this utility model's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this utility model patent.

Claims

1. An apparatus for adjusting the concentration of hydrofluoric acid in water, characterized in that, It includes a pure water tank, a first regulating valve, a first flow meter, a mixer, a raw material tank, a second regulating valve, a second flow meter, an intermediate tank, a third pump, a weighing sensor, a third flow meter, and a third regulating valve; The outlet of the pure water tank is connected to the inlet of the mixer through a first pipe, and the first pipe is equipped with the first regulating valve and the first flow meter; The outlet of the raw material tank is connected to the inlet of the mixer through a second pipe, and the second pipe is equipped with a second regulating valve and a second flow meter; The outlet of the mixer is connected to the inlet of the intermediate tank through a third pipe, and the outlet of the intermediate tank is connected to the inlet of the mixer through a fourth pipe. The third pump is installed on the fourth pipe, and the intermediate tank is installed on the weighing sensor. The outlet of the mixer is connected to a fifth pipe, and the fifth pipe is equipped with a third flow meter and a third regulating valve.

2. The apparatus according to claim 1, characterized in that, It also includes a condenser, which is provided on the third pipe and / or the fifth pipe.

3. The apparatus according to claim 2, characterized in that, The third pipe and the fifth pipe are connected to form a main pipe and two branch pipes, namely the first branch pipe and the second branch pipe. The main pipe is connected to the outlet of the mixer and the condenser is installed on the main pipe. The first branch pipe is connected to the inlet of the intermediate tank and the second branch pipe is equipped with a third flow meter and the third regulating valve.

4. The apparatus according to claim 1, characterized in that, It also includes a first pump, which is disposed on the first pipeline; and / or: It also includes a second pump, which is installed on the second pipeline.

5. The apparatus according to claim 4, characterized in that, The first pump is a pure water pump, and the second pump is a diaphragm pump.

6. The apparatus according to claim 1, characterized in that, Also includes: The first pneumatic shut-off valve is located on the first pipeline.

7. The apparatus according to claim 1, characterized in that, Also includes: The second pneumatic shut-off valve is located on the second pipeline.

8. The apparatus according to claim 1, characterized in that, There are multiple weighing sensors.

9. The apparatus according to claim 1, characterized in that, Also includes: A thermometer is disposed in the mixer; as well as The controller, together with the thermometer, the first regulating valve, the second regulating valve, the third pump, and the third regulating valve, controls the first regulating valve, the second regulating valve, the third pump, and the third regulating valve to close after the thermometer detects that the temperature of the mixer exceeds a temperature threshold.

10. The apparatus according to claim 1, characterized in that, Also includes: A level gauge is disposed in the mixer; as well as The controller is connected to the level gauge, the first regulating valve, the second regulating valve, the third pump, and the third regulating valve. After the level gauge detects that the liquid level in the intermediate tank exceeds the liquid level threshold, the controller controls the first regulating valve, the second regulating valve, the third pump, and the third regulating valve to close.

Images