Differential pressure liquid level measurement system with dynamic density compensation

Abstract

The utility model discloses a differential pressure liquid level measuring system with dynamic density compensation for pressure vessel with first and second pressure lead pipes, which comprises a first and a second measuring assembly, a density sensor and a liquid level measuring instrument. The first measuring assembly is composed of a first pipeline and a first pressure transmitter connected to the end of the first pipeline, and is connected to the first pressure lead pipe. The second measuring assembly comprises a second pipeline, a sight glass and a second pressure transmitter. The second pipeline is connected to the second pressure lead pipe. The sight glass is arranged at the end of the pipeline. The second pressure transmitter is installed at the other end of the sight glass. The density sensor is arranged outside the container to detect the density of the liquid. The liquid level measuring instrument receives the signals of the density sensor and the two pressure transmitters through a signal port, processes the signals through a controller and outputs the liquid level data. The utility model significantly improves the measurement accuracy through density compensation. The split type pressure transmitter is easy to replace individually to reduce the maintenance cost. The state of the pressure lead pipe can be observed through the sight glass structure, and the crystallization blockage can be removed in time.

Description

Technical Field

[0001] This utility model relates to the field of pressure detection technology, and in particular to a differential pressure liquid level measurement system with dynamic density compensation. Background Technology

[0002] In solution evaporation and concentration processes in chemical and pharmaceutical industries, pressure vessels (such as separators in triple-effect evaporation systems) are often used to achieve gas-liquid separation. The accuracy of liquid level control in such pressure vessels directly determines the evaporation effect and production stability. If the liquid level is too high, it can easily lead to abnormal liquid leakage. If the liquid level is too low, it may cause material crystallization and block the container. Both require shutdown for maintenance, which has a significant impact on production continuity and economy. Therefore, accurate and reliable liquid level measurement methods are urgently needed to support liquid level control.

[0003] Currently, the industry commonly uses differential pressure transmitters with dual-flange capillary pressure tapping to measure the liquid level in the aforementioned pressure vessels. The core principle is to extract the differential pressure signal from the upper and lower parts of the vessel through a capillary tube, and then calculate the liquid level value by combining it with a preset liquid density. However, this measurement method has significant drawbacks in practical applications: Firstly, the pressure vessel contains components such as a cyclone demister and operates under high temperature and negative pressure conditions, resulting in turbulent gas-liquid mixing. Simultaneously, the liquid easily crystallizes in the pressure tapping pipeline and at the sensor, causing uneven stress on the pressure diaphragm, deformation, and damage. Typically, these diaphragms require complete scrapping after 3-6 months of use, leading to high maintenance costs. Furthermore, early diaphragm damage is difficult to detect visually, easily resulting in erroneous liquid level signals. Secondly, during production, the density of the liquid inside the vessel changes dynamically due to continuous evaporation and the extraction of qualified materials. Traditional differential pressure measurement methods can only calculate based on a fixed water density, failing to achieve dynamic density compensation, further amplifying the liquid level measurement error. This causes the centralized control system to perform liquid replenishment control based on erroneous liquid level signals, leading to production accidents such as crystallization blockage or liquid leakage.

[0004] Therefore, it is necessary to propose a differential pressure level measurement system with dynamic density compensation. Summary of the Invention

[0005] The purpose of this invention is to at least partially address the shortcomings of the existing technology, thereby proposing a differential pressure level measurement system with dynamic density compensation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model provides a differential pressure liquid level measurement system with dynamic density compensation for a pressure vessel. The pressure vessel has a first pressure tap and a second pressure tap arranged sequentially from top to bottom. The system includes a first measuring component, a second measuring component, a density sensor, and a liquid level measuring instrument.

[0008] The first measuring component includes a first conduit and a first pressure transmitter, wherein the first pressure transmitter is connected to the first pressure tap via the first conduit; the first pressure transmitter is installed at the end of the first conduit away from the first pressure tap.

[0009] The second measuring component includes a second pipe, a sight glass, and a second pressure transmitter. The second pipe is connected to the second pressure tap. The sight glass is installed at the end of the second pipe away from the second pressure tap, and the second pipe communicates with the inner cavity of the sight glass. The second pressure transmitter is installed at the end of the sight glass away from the second pipe. The pressure vessel has a connection port for connecting to an external pipeline, and the density sensor is located on the external pipeline to detect the density of the liquid flowing through the external pipeline.

[0010] The liquid level measuring instrument includes a controller, a display unit, a signal input port, and a signal output port; the outputs of the density sensor, the first pressure transmitter, and the second pressure transmitter are electrically connected to the input of the controller through the signal input port, respectively.

[0011] In an optional embodiment, a third conduit is connected to the sight glass, the third conduit communicating with the inner cavity of the sight glass to introduce a dissolving medium into the inner cavity of the sight glass;

[0012] The third pipe is connected to the top of the sight glass, and a first control valve is provided on the third pipe. The input end of the first control valve is electrically connected to the output end of the controller through a signal output port.

[0013] In an optional embodiment, a fourth pipe is connected to the sight glass, the fourth pipe communicating with the inner cavity of the sight glass to guide the liquid inside the inner cavity of the sight glass out of the inner cavity of the sight glass.

[0014] The fourth pipe is connected to the bottom end of the sight glass, and a first manual valve is provided on the fourth pipe.

[0015] In one optional implementation, the first conduit includes a first flow channel and a second flow channel;

[0016] The first end of the first flow channel is connected to the first pressure pipe through a first flange structure; one end of the second flow channel is connected to the second end of the first flow channel through a second flange structure, and the other end of the second flow channel is connected to the first pressure transmitter; a second manual valve is provided on the first flow channel.

[0017] In one optional implementation, the second conduit includes a third flow channel and a fourth flow channel;

[0018] The first end of the third flow channel is connected to the second pressure pipe through a third flange structure; one end of the fourth flow channel is connected to the second end of the third flow channel through a fourth flange structure, and the other end of the fourth flow channel is connected to the inner cavity of the sight glass; a third manual valve is provided on the third flow channel.

[0019] In one optional embodiment, the liquid level measuring instrument further includes a housing, with the controller disposed inside the housing; the signal input port, signal output port, and display unit are all disposed on the surface of the housing;

[0020] The display unit is a touch screen, or the display unit includes a digital tube and operation buttons.

[0021] In an optional embodiment, the liquid level measuring instrument further includes an alarm, the input of which is electrically connected to the output of the controller via a signal output port.

[0022] In one alternative implementation, the first conduit includes a first ball valve, and the second conduit includes a second ball valve;

[0023] The inlet end of the first ball valve is connected to the first pressure tap flange, and the outlet end of the first ball valve is connected to the first pressure transmitter flange; the inlet end of the second ball valve is connected to the second pressure tap flange, and the outlet end of the second ball valve is connected to the sight glass flange.

[0024] In one optional embodiment, the sight glass includes a sight glass housing and an observation window, the observation window being installed at an observation port opened on the side of the housing; the sight glass housing is made of titanium alloy.

[0025] In an optional embodiment, the sealing diaphragms of the density sensor, the first pressure transmitter, and the second pressure transmitter are all made of Hastelloy.

[0026] The beneficial effects of the embodiments provided by this utility model include:

[0027] This invention connects two pressure transmitters to the first and second pressure taps respectively, and combines them with a density sensor and a level measuring instrument in the pressure vessel to construct a density compensation mechanism, significantly improving the accuracy of level measurement. Through the split-type pressure transmitter structure design, only the corresponding component needs to be replaced when a single transmitter fails, eliminating the need for complete scrapping and reducing equipment maintenance and replacement costs. The sight glass structure at the end of the second pressure tap allows for direct observation of the material state inside the lower pressure tap, facilitating timely detection of abnormalities such as crystallization and blockage. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0029] Figure 1 A schematic diagram of one side of the differential pressure level measurement system with dynamic density compensation in an embodiment of this specification is shown.

[0030] Figure 2 A schematic diagram of the other side of the differential pressure level measurement system with dynamic density compensation in an embodiment of this specification is shown;

[0031] Figure 3 A detailed view of part A of the differential pressure level measurement system with dynamic density compensation in an embodiment of this specification is shown;

[0032] Figure 4 A detailed view of part B of the differential pressure level measurement system with dynamic density compensation in an embodiment of this specification is shown.

[0033] Figure 5 A structural diagram of the liquid level measuring instrument in the embodiments of this specification is shown.

[0034] Wherein, 1 is a pressure vessel; 101 is the first pressure tap; 102 is the second pressure tap; 103 is the inlet; 104 is the outlet; 105 is the second observation window; 2 is the first pipeline; 201 is the second manual valve; 202 is the first flange structure; 203 is the second flange structure; 3 is the second pipeline; 301 is the third manual valve; 302 is the third flange structure; 303 is the fourth flange structure; 4 is a sight glass; 401 is the third pipeline; 402 is the fourth pipeline; 403 is the second manual valve; 104 is the third manual valve; 105 is the fourth manual valve; 106 is the third manual valve; 107 is the third manual valve; 108 is the third manual valve; 109 is the third manual valve; 1000 is the third manual valve; 101 is the third manual valve; 102 is the fourth manual valve; 105 is the second manual valve; 106 is the third manual valve; 107 is the third manual valve; 108 is the third manual valve; 109 is the third manual valve; 1000 is the third manual valve; 101 is the third manual valve; 1000 is the fourth manual valve; 101 is the third manual valve; 102 is the fourth manual valve; 103 is the second manual valve; 104 is the third manual valve; 105 is the fourth manual valve; 106 is the third manual valve; 107 is the third manual valve; 108 is the third manual valve; 109 is the fourth manual valve; 1000 is the third manual valve; 1000 is the fourth manual valve; 1000 is the fourth manual valve; 101 is the third manual valve; 1000 is the fourth manual valve; 101 is the third manual valve; 1000 is the fourth manual valve; 101 is the third 1. Control valve; 404 is the first manual valve; 405 is the first observation window; 5 is the first pressure transmitter; 6 is the second pressure transmitter; 7 is the level measuring instrument; 701 is the housing; 702 is the display unit; 703 is the first pressure signal input port; 704 is the second pressure signal input port; 705 is the density signal input port; 706 is the power signal input port; 707 is the analog output port; 708 is the digital output port; 709 is the control signal output port. Detailed Implementation

[0035] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0036] Example 1

[0037] As shown in Figure 1 - Figure 5 As shown, this embodiment discloses a differential pressure liquid level measurement system with dynamic density compensation for a pressure vessel 1. The pressure vessel 1 has a first pressure tap 101 and a second pressure tap 102 arranged sequentially from top to bottom. The system includes a first measurement component, a second measurement component, a density sensor, and a liquid level measuring instrument.

[0038] For example, the first measuring component includes a first pipe 2 and a first pressure transmitter 5, the first pressure transmitter 5 being connected to the first pressure tap 101 via the first pipe 2; the first pressure transmitter 5 is installed at the end of the first pipe 2 away from the first pressure tap 101 and is used to detect the fluid pressure in the first pipe 2.

[0039] The second measuring component includes a second pipe 3, a sight glass 4, and a second pressure transmitter 6. The second pipe 3 is connected to the second pressure tap 102. The sight glass 4 is installed at the end of the second pipe 3 away from the second pressure tap 102, and the second pipe 3 communicates with the inner cavity of the sight glass 4. The second pressure transmitter 6 is installed at the end of the sight glass 4 away from the second pipe 3 and is used to detect the fluid pressure flowing through the inner cavity.

[0040] The pressure vessel 1 has a connection port for connecting to an external pipeline, and a density sensor is installed on the external pipeline to detect the density of the liquid flowing through the external pipeline;

[0041] The liquid level measuring instrument includes a controller, a display unit 702, a signal input port, and a signal output port. The outputs of the density sensor, the first pressure transmitter 5, and the second pressure transmitter 6 are electrically connected to the input of the controller via the signal input port. The output of the controller is electrically connected to the display unit 702 and the signal output port. In this embodiment, the controller is a microcontroller or a PLC.

[0042] In some embodiments, the signal input port includes a first pressure signal input port 703, a second pressure signal input port 704, a density signal input port 705, and a power signal input port 706; the output port unit includes an analog output port 707, a digital output port 708, and a control signal output port 709.

[0043] Specifically, the output terminal of the first pressure transmitter 5 is electrically connected to the input terminal of the first pressure signal input port 703, and the output terminal of the first pressure signal input port 703 is electrically connected to the input terminal of the controller, so as to receive the pressure signal sent by the first pressure transmitter 5 and send it to the controller;

[0044] The output terminal of the second pressure transmitter 6 is electrically connected to the input terminal of the second pressure signal input port 704, and the output terminal of the second pressure signal input port 704 is electrically connected to the input terminal of the controller, so as to receive the pressure signal sent by the second pressure transmitter 6 and send it to the controller.

[0045] The input terminal of the density signal input port 705 is electrically connected to the output terminal of the density sensor, and the output terminal of the density signal input port 705 is electrically connected to the input terminal of the controller, so as to receive the 4~20mA analog density signal sent by the density sensor and send it to the controller;

[0046] The input terminal of the power signal input port 706 is electrically connected to the output terminal of the external power supply, and the output terminal of the power signal input port 706 is electrically connected to the input terminal of the controller.

[0047] In some embodiments, a third pipe 401 and a fourth pipe 402 are connected to the viewing mirror 4;

[0048] Specifically, the third pipe 401 is connected to the top of the sight glass 4 and communicates with the inner cavity of the sight glass 4 to introduce a dissolving medium into the inner cavity of the sight glass 4 to dissolve the crystals; the fourth pipe 402 is connected to the bottom of the sight glass 4 and communicates with the inner cavity of the sight glass 4 to guide the liquid in the inner cavity of the sight glass 4 to flow out of the inner cavity of the sight glass 4.

[0049] The third pipe 401 is equipped with a first control valve 403, and the fourth pipe 402 is equipped with a first manual valve 404. The input end of the first control valve 403 is electrically connected to the output end of the controller through the control signal output port 709.

[0050] In this embodiment, when severe crystallization is observed through the first observation window 405 on the sight glass 4, the first solenoid valve can be opened by controlling the liquid level measuring instrument to introduce a dissolving medium to dissolve the crystals, thereby ensuring the pressure tapping pipe remains unobstructed. Alternatively, the interval and duration of automatically introducing the dissolving medium can be set to achieve timed automatic flushing, effectively preventing adverse effects on the accuracy of the liquid level measurement due to crystal accumulation. It should also be noted that, under normal circumstances, the dissolved liquid is still considered normal process material and can be directly recycled back into the production process without additional discharge.

[0051] In this embodiment, the dissolving medium is water or a specific solution with a density lower than that of the process medium in pressure vessel 1. The operator can select and adjust the solution according to the actual working conditions and the properties of the crystals.

[0052] In addition, in this embodiment, the first manual valve 404 on the fourth pipe 402 is mainly used to perform regular manual drainage when a lot of slag or debris accumulates inside the sight glass 4, so as to ensure the cleanliness of the inside of the sight glass 4 and the long-term stable operation of the system.

[0053] In some embodiments, the first pipe 2 includes a first flow channel and a second flow channel;

[0054] Specifically, the first end of the first flow channel is connected to the first pressure tap 101 via the first flange structure 202; one end of the second flow channel is connected to the second end of the first flow channel via the second flange structure 203, and the other end is connected to the first pressure transmitter 5.

[0055] In some embodiments, the second conduit 3 includes a third flow channel and a fourth flow channel;

[0056] Specifically, the first end of the third flow channel is connected to the second pressure pipe 102 through the third flange structure 302; one end of the fourth flow channel is connected to the second end of the third flow channel through the fourth flange structure 303, and the other end is connected to the inner cavity of the sight glass 4.

[0057] The first flow channel is equipped with a second manual valve 201, and the third flow channel is equipped with a third manual valve 301. This allows the operator to simply close the corresponding manual valve to cut off the pipeline when the first pressure transmitter 5 or the second pressure transmitter 6 malfunctions and needs to be replaced or repaired. This enables the pressure transmitter to be quickly and safely disassembled and replaced, effectively solving the problem of online maintenance and improving the maintainability and operational safety of the system.

[0058] In some embodiments, the liquid level measuring instrument further includes a housing 701 and an alarm. The controller is disposed inside the housing 701, and the signal input port, signal output port, and display unit 702 are all disposed on the surface of the housing 701. The alarm is fixedly disposed on one side of the housing 701, and the input terminal of the alarm is electrically connected to the output terminal of the switch output port 708, so as to provide an audible and visual alarm when the liquid level in the pressure vessel 1 is lower or higher than a preset threshold, so as to remind relevant personnel.

[0059] The display unit 702 is a touch screen, or the display unit 702 includes a digital tube and operation buttons; the operation buttons include a power switch, an OK button, directional buttons, a reset button, a return button, and increment / decrement buttons for various menu settings in the operation interface.

[0060] In some embodiments, the pressure vessel 1 further includes an inlet 103 and an outlet 104; wherein, an inlet pump is provided at the inlet 103 and an outlet pump is provided at the outlet 104.

[0061] Specifically, the controller is electrically connected to an external centralized control system via analog output port 707, and the external centralized control system is electrically connected to the feed pump and / or discharge pump of pressure vessel 1.

[0062] The controller sends the processed liquid level signal and / or alarm signal to the external centralized control system through the analog output port 707. The external centralized control system controls the start and stop of the feed pump and / or discharge pump according to the received signal, thereby realizing the automatic control of the liquid level of pressure vessel 1.

[0063] In this embodiment, the outlet 104 of the pressure vessel 1 serves as the connection port. The density sensor is installed on an external pipe connected to the outlet 104 of the pressure vessel 1. Since the liquid inside the pressure vessel 1 is kept uniformly mixed under the action of agitators, the density of the outflowing liquid can accurately reflect the real-time density of the liquid inside the container. This installation method avoids the problems of easy clogging, easy corrosion, and difficult maintenance caused by placing the sensor directly inside the container in a harsh environment. It realizes online maintenance and replacement without interrupting production, which significantly improves the reliability of the system.

[0064] In some embodiments, the sight glass 4 includes a sight glass housing and a first observation window 405; the first observation window 405 is installed at an observation port opened on the side of the housing, and a sealing gasket is provided between the first observation window 405 and the housing. The pressure vessel 1 is provided with a plurality of second observation windows 105 for observing the interior of the pressure vessel 1.

[0065] In this embodiment, the sight glass housing, the first flange structure 202, the second flange structure 203, the third flange structure 302, and the fourth flange structure 303 are all made of titanium alloy; the sealing diaphragms of the density sensor, the first pressure transmitter 5, and the second pressure transmitter 6 are all made of Hastelloy alloy to enhance the corrosion resistance of some equipment in the system.

[0066] Example 2

[0067] This embodiment provides a differential pressure level measurement system with dynamic density compensation. The difference between this system and Embodiment 1 is that the first pipeline 2 is entirely composed of a first ball valve, and the second pipeline 3 is entirely composed of a second ball valve.

[0068] Specifically, the inlet end of the first ball valve is connected to the first pressure pipe 101 via a flange, and the outlet end of the first ball valve is connected to the first pressure transmitter 5 via a flange; the inlet end of the second ball valve is connected to the second pressure pipe 102 via a flange, and the outlet end of the first ball valve is connected to the inner cavity of the sight glass 4 via a flange.

[0069] In this embodiment, the first ball valve and the second ball valve are ball valves with a nominal diameter of DN50. The ball valve itself has both pipeline flow and shut-off functions. The full nominal diameter of the ball valve provides a flow channel with low flow resistance and is not easy to block, which is very suitable for media that are prone to crystallization, contain impurities or are viscous.

[0070] Therefore, when it is necessary to repair or replace the pressure transmitter, simply rotate the corresponding valve to the closed position to safely cut off the flow of the medium, thereby achieving instrument isolation and disassembly. This embodiment integrates the functions of the traditional "pipeline + valve group" into a single ball valve body, which greatly simplifies the system structure, reduces potential leakage points, and improves the sealing reliability and maintenance convenience of the system.

[0071] Example 3

[0072] This embodiment provides a differential pressure level measurement system with dynamic density compensation. The difference between this system and Embodiment 1 is that the first manual valve 404, the second manual valve 201, and the third manual valve 301 are all replaced with solenoid valve structures.

[0073] Specifically, a second solenoid valve is installed on the fourth pipe 402. The input end of the second solenoid valve is electrically connected to the output end of the controller through the control signal output port 709, so as to open the second solenoid valve according to the remote control or periodic control of the controller, so as to realize periodic automatic sewage discharge.

[0074] A third solenoid valve is installed on the first flow channel, and a fourth solenoid valve is installed on the third flow channel. The input terminals of the third and fourth solenoid valves are electrically connected to the output terminal of the controller through the control signal output port 709, respectively, so as to remotely control the second or third solenoid valve to close when the pressure transmitter needs to be isolated for maintenance.

[0075] This embodiment reduces the need for manual operation, making it particularly suitable for hazardous or inaccessible industrial environments.

[0076] It should be noted that the controller in this embodiment is a physical hardware entity containing hardware modules for signal acquisition, data processing, and output control. The specific functions and methods performed by these modules are existing technology and not the innovation of this invention. The innovation of this invention lies in the creative combination of the above hardware structures to form a new physical device structure, making it more suitable for the specific application scenario of liquid level measurement under high temperature, negative pressure, and easily crystallizing conditions. The beneficial effects of this invention stem from the hardware structure design in the above embodiments, rather than the software methods or algorithms executed therein.

[0077] That is, the above embodiments do not involve the formulation of strategies or the improvement of methods.

[0078] In summary, this embodiment uses a separate first and second pressure transmitter to replace the traditional integrated dual-flange differential pressure transmitter. When a single pressure measuring element is damaged, it can be directly replaced, avoiding the scrapping of the entire device and significantly reducing equipment maintenance and operating costs.

[0079] In this embodiment, a sight glass structure is installed at the end of the second pressure tapping pipe, which enables visual observation of the measurement point status. Maintenance personnel can directly observe the crystallization and blockage of the pressure tapping point through the sight glass, which greatly improves the maintainability and fault identification efficiency of the system. Furthermore, the sight glass structure is equipped with flushing and drainage interfaces, which provides a hardware basis for the system to be flushed and cleaned regularly, effectively preventing the blockage of the pressure tapping pipe and ensuring the long-term stability of pressure measurement.

[0080] In this embodiment, by using a flush diaphragm pressure transmitter and a mounting method at the end of the sight glass, the crystallization and adhesion of materials on the surface of the measuring diaphragm are effectively reduced. At the same time, the sight glass made of titanium alloy and the Hastelloy diaphragm significantly improve the durability of the system in corrosive environments.

[0081] In this embodiment, by adding a density sensor and connecting it together with a pressure transmitter to the liquid level measuring instrument, a hardware measurement system with real-time density feedback is constructed, which effectively solves the liquid level measurement error caused by changes in medium density and significantly improves the measurement accuracy.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A differential pressure level measurement system with dynamic density compensation, used in a pressure vessel, the pressure vessel having a first pressure tap and a second pressure tap arranged sequentially from top to bottom, characterized in that, The system includes a first measuring component, a second measuring component, a density sensor, and a liquid level measuring instrument; The first measuring component includes a first conduit and a first pressure transmitter, wherein the first pressure transmitter is connected to the first pressure tap via the first conduit; the first pressure transmitter is installed at the end of the first conduit away from the first pressure tap. The second measuring component includes a second pipe, a sight glass, and a second pressure transmitter. The second pipe is connected to the second pressure tap. The sight glass is installed at the end of the second pipe away from the second pressure tap, and the second pipe is in communication with the sight glass. The second pressure transmitter is installed at the end of the sight glass away from the second pipe. The pressure vessel has a connection port for connecting to an external pipeline, and the density sensor is located on the external pipeline to detect the density of the liquid flowing through the external pipeline. The liquid level measuring instrument includes a controller, a display unit, a signal input port, and a signal output port; the outputs of the density sensor, the first pressure transmitter, and the second pressure transmitter are electrically connected to the input of the controller through the signal input port, respectively; the output of the controller is electrically connected to the display unit and the signal output port, respectively.

2. The system according to claim 1, characterized in that, A third pipe is connected to the sight glass, and the third pipe communicates with the inner cavity of the sight glass to introduce a dissolving medium into the inner cavity of the sight glass; The third pipe is connected to the top of the sight glass, and a first control valve is provided on the third pipe. The input end of the first control valve is electrically connected to the output end of the controller through a signal output port.

3. The system according to claim 2, characterized in that, A fourth pipe is connected to the sight glass, and the fourth pipe communicates with the inner cavity of the sight glass to guide the liquid in the inner cavity of the sight glass to flow out of the inner cavity of the sight glass. The fourth pipe is connected to the bottom end of the sight glass, and a first manual valve is provided on the fourth pipe.

4. The system according to claim 1, characterized in that, The first conduit includes a first flow channel and a second flow channel; The first end of the first flow channel is connected to the first pressure pipe through a first flange structure; one end of the second flow channel is connected to the second end of the first flow channel through a second flange structure, and the other end of the second flow channel is connected to the first pressure transmitter; a second manual valve is provided on the first flow channel.

5. The system according to claim 1, characterized in that, The second conduit includes a third flow channel and a fourth flow channel; The first end of the third flow channel is connected to the second pressure pipe through a third flange structure; one end of the fourth flow channel is connected to the second end of the third flow channel through a fourth flange structure, and the other end of the fourth flow channel is connected to the inner cavity of the sight glass; a third manual valve is provided on the third flow channel.

6. The system according to claim 1, characterized in that, The liquid level measuring instrument also includes a housing, and the controller is disposed inside the housing; the signal input port, the signal output port and the display unit are all disposed on the surface of the housing; The display unit is a touch screen, or the display unit includes a digital tube and operation buttons.

7. The system according to claim 6, characterized in that, The liquid level measuring instrument also includes an alarm, the input of which is electrically connected to the output of the controller via a signal output port.

8. The system according to claim 1, characterized in that, The first pipeline includes a first ball valve, and the second pipeline includes a second ball valve; The inlet end of the first ball valve is connected to the first pressure tap flange, and the outlet end of the first ball valve is connected to the first pressure transmitter flange; the inlet end of the second ball valve is connected to the second pressure tap flange, and the outlet end of the second ball valve is connected to the sight glass flange.

9. The system according to claim 1, 2, 3 or 5, characterized in that, The sight glass includes a sight glass housing and an observation window, the observation window being installed at an observation port on the side of the housing; the sight glass housing is made of titanium alloy.

10. The system according to claim 1, characterized in that, The sealing diaphragms of the density sensor, the first pressure transmitter, and the second pressure transmitter are all made of Hastelloy.

Images