A liquid level measuring device

Abstract

This utility model discloses a liquid level measuring device, relating to the field of backflush liquid level gauge technology. It includes a pressure reducing valve, a positive pressure pipeline system, a negative pressure pipeline system, a differential pressure transmitter, a positive pressure measuring rod, a negative pressure measuring rod, a positive pressure guide rod, a heat tracing jacket, and heat tracing flanges. The pressure reducing valve connects the positive pressure pipeline system and the negative pressure pipeline system. The positive pressure pipeline system connects the differential pressure transmitter and the positive pressure measuring rod. A positive pressure guide rod is fitted around the outer side of the positive pressure measuring rod, and a heat tracing jacket is fitted around the outer side of the positive pressure guide rod. Two heat tracing flanges are installed on one side of the heat tracing jacket. The negative pressure pipeline system connects the differential pressure transmitter and the negative pressure measuring rod. Through the heat tracing jacket and heat tracing flanges, and the circulation of the internal heat tracing medium, the temperature of the positive pressure measuring rod and its surrounding area can be maintained, preventing condensation or freezing of the medium inside the pipeline due to low external temperatures, thus ensuring the smooth flow of the positive pressure pipeline system and the stability of the pressure signal transmission.

Description

Technical Field

[0001] This utility model relates to the field of backflush level gauge technology, and in particular to a level measuring device. Background Technology

[0002] In the petrochemical and synthetic fiber production process, accurate measurement of the liquid level inside the high-temperature reactor is crucial for the safe and stable operation of production. Currently, the main methods for measuring the liquid level in high-temperature reactors are radioactive level gauges or dual-flange level gauges. However, both of these traditional methods have significant limitations.

[0003] While radioactive level gauges offer certain advantages in measurement accuracy, their management is extremely stringent. Due to the serious health hazards posed by radioactive materials, strict regulations and safety standards must be followed in all aspects of their use, transportation, and storage. Because the viscosity, temperature, and vacuum level of the medium inside the reactor are relatively high, dual-flange level gauges cannot withstand the demands of long-term operation, frequently malfunctioning and causing level measurement failures, which seriously impacts safety and production. Utility Model Content

[0004] The purpose of this invention is to provide a liquid level measuring device to solve the above-mentioned technical problems.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A liquid level measuring device includes a pressure reducing valve, a positive pressure pipeline system, a negative pressure pipeline system, a differential pressure transmitter, a positive pressure measuring rod, a negative pressure measuring rod, a positive pressure guide rod, a heat tracing jacket, and a heat tracing flange. The pressure reducing valve connects the positive pressure pipeline system and the negative pressure pipeline system. The positive pressure pipeline system connects the differential pressure transmitter and the positive pressure measuring rod. The positive pressure guide rod is sleeved on the outer side of the positive pressure measuring rod. The heat tracing jacket is sleeved on the outer side of the positive pressure guide rod. Two heat tracing flanges are provided on one side of the heat tracing jacket. The negative pressure pipeline system connects the differential pressure transmitter and the negative pressure measuring rod.

[0007] Preferably, the device also includes a measuring flange and a negative pressure guide rod, wherein the negative pressure guide rod is sleeved on the outside of the negative pressure measuring rod, and both the positive pressure guide rod and the negative pressure guide rod pass through the measuring flange, and one end of the heat tracing jacket is connected to the measuring flange.

[0008] Preferably, the two heat tracing flanges are connected to the heat tracing jacket pipe via connecting rods.

[0009] Preferably, the system also includes a first air passage three-way valve, through which the pressure reducing valve is connected to the positive pressure pipeline system and the negative pressure pipeline system.

[0010] As a further preferred embodiment, the positive pressure pipeline system includes a second air three-way valve, a first air pipe, a second air pipe, a third air pipe, and a sealing joint. The first air pipe connects the second air three-way valve and the first air three-way valve. The second air pipe connects the second air three-way valve and the positive pressure interface of the differential pressure transmitter. The third air pipe connects the second air three-way valve and the sealing joint.

[0011] As a further preferred embodiment, the system also includes a first ball valve and a second ball valve, wherein the first ball valve is connected to the sealing joint and the positive pressure measuring rod, and the second ball valve is provided on the third air pipe.

[0012] As a further preferred embodiment, the negative pressure pipeline system includes a fourth gas pipe, a fifth gas pipe, a sixth gas pipe, a third gas three-way valve, and a fourth gas three-way valve. The fourth gas pipe connects the third gas three-way valve and the first gas three-way valve. The fifth gas pipe connects the third gas three-way valve and the negative pressure interface of the differential pressure transmitter. The sixth gas pipe connects the third gas three-way valve and the fourth gas three-way valve.

[0013] As a further preferred embodiment, the system also includes a third ball valve, a fourth ball valve, and a fifth ball valve. The third ball valve is installed on the sixth air pipe, and the fourth and fifth ball valves are respectively connected to the fourth air passage three-way valve. The negative pressure measuring rod is connected to the fifth ball valve.

[0014] The above technical solution has the following advantages or beneficial effects:

[0015] (1) In this utility model, the setting of the heat tracing jacket and heat tracing flange can maintain the temperature of the positive pressure measuring rod and the surrounding area through the circulation of the internal heat tracing medium, prevent the medium in the pipeline from condensing or freezing due to the low temperature of the outside, and ensure the smooth flow of the positive pressure pipeline system and the stability of the pressure signal transmission.

[0016] (2) In this utility model, by setting up a positive pressure pipeline system, a negative pressure pipeline system, a differential pressure transmitter, a positive pressure measuring rod and a negative pressure measuring rod, the measurement of positive pressure and negative pressure can be realized. The differential pressure transmitter receives the accurate pressure signals transmitted by the positive pressure pipeline system and the negative pressure pipeline system, and converts the difference between the two into liquid level height data by accurately calculating the difference between them. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the liquid level measuring device in this utility model.

[0018] In the diagram: 1. Pressure reducing valve; 2. Differential pressure transmitter; 3. Positive pressure measuring rod; 4. Positive pressure guide rod; 5. Heat tracing jacket; 6. Heat tracing flange; 7. Measuring flange; 8. Negative pressure guide rod; 9. First air path three-way valve; 10. Second air path three-way valve; 11. First air pipe; 12. Second air pipe; 13. Third air pipe; 14. Sealing joint; 15. First ball valve; 16. Second ball valve; 17. Fourth air pipe; 18. Fifth air pipe; 19. Sixth air pipe; 20. Third air path three-way valve; 21. Fourth air path three-way valve; 22. Third ball valve; 23. Fourth ball valve; 24. Fifth ball valve. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] Figure 1 This is a schematic diagram of the liquid level measuring device in this utility model. Please refer to it. Figure 1The diagram illustrates a preferred embodiment of a liquid level measuring device, comprising a pressure reducing valve 1, a positive pressure pipeline system, a negative pressure pipeline system, a differential pressure transmitter 2, a positive pressure measuring rod 3, a negative pressure measuring rod, a positive pressure guide rod 4, a heat tracing jacket pipe 5, and a heat tracing flange 6. The pressure reducing valve 1 connects to the positive pressure pipeline system and the negative pressure pipeline system. The positive pressure pipeline system connects the differential pressure transmitter 2 and the positive pressure measuring rod 3. A positive pressure guide rod 4 is sleeved on the outer side of the positive pressure measuring rod 3, and a heat tracing jacket pipe 5 is sleeved on the outer side of the positive pressure guide rod 4. Two heat tracing flanges 6 are provided on one side of the heat tracing jacket pipe 5. The negative pressure pipeline system connects the differential pressure transmitter 2 and the negative pressure measuring rod. In this embodiment, external gas (nitrogen) is reduced to 0.25 MPa after passing through pressure reducing valve 1, and then enters the negative pressure pipeline system and the positive pressure pipeline system. The gas passing through the positive pressure pipeline system is split into two paths, entering the positive pressure measuring rod 3 and the differential pressure transmitter 2 respectively. The gas passing through the negative pressure pipeline system is also split into two paths, entering the negative pressure measuring rod and the differential pressure transmitter 2 respectively. The measuring flange 7 is used to install on the upper end of the reactor and can be used to fix the heat tracing jacket 5.

[0023] In this embodiment, a positive pressure guide rod 4 is provided on the outside of the positive pressure measuring rod 3, and a heat tracing jacket pipe 5 is provided on the outside of the positive pressure guide rod 4. A heat tracing flange 6 is connected to the heat tracing jacket pipe 5 via a connecting rod. The connecting rod is a hollow rod-shaped structure. The connecting rod communicates with the through hole in the middle of the heat tracing flange 6 and the heat tracing jacket pipe 5. The through hole in the middle of one heat tracing flange 6 is the inlet, and the through hole in the middle of the other heat tracing flange 6 is the outlet. The inlet and outlet can be connected to an external heat tracing medium supply device to continuously supply heat tracing medium (heated water or hot air) into the interior of the heat tracing jacket pipe 5. This can maintain the temperature of the positive pressure measuring rod 3 and its surrounding area, avoid the influence of external low temperature on the transmission of the medium inside the positive pressure measuring rod 3, and ensure the smooth flow of the positive pressure pipeline system and the stability of the pressure signal transmission. In this embodiment, a heat tracing jacket pipe 5 and a heat tracing flange 6 can also be provided on the outside of the negative pressure guide rod 8 to maintain the temperature of the negative pressure measuring rod and its surrounding area.

[0024] Furthermore, as a preferred embodiment, it also includes a measuring flange 7 and a negative pressure guide rod 8. The negative pressure guide rod 8 is sleeved on the outside of the negative pressure measuring rod. Both the positive pressure guide rod 4 and the negative pressure guide rod 8 penetrate the measuring flange 7. One end of the heat tracing jacket pipe 5 is connected to the measuring flange 7. In this embodiment, see... Figure 1 As shown, the heat tracing jacket 5 is installed at the upper end of the measuring flange 7, and the lower end of the heat tracing jacket 5 is welded to the measuring flange 7. The lower end of the positive pressure guide rod 4 passes through the measuring flange 7, and the outer wall of the positive pressure guide rod 4 is welded to the measuring flange 7.

[0025] Furthermore, as a preferred embodiment, it also includes a first gas path three-way valve 9, through which the pressure reducing valve 1 is connected to the positive pressure pipeline system and the negative pressure pipeline system. The first gas path three-way valve 9 is used to divide the pressure-reduced gas into two parts, one part of which enters the positive pressure pipeline system and the other part of which enters the negative pressure pipeline system.

[0026] Furthermore, as a preferred embodiment, the positive pressure pipeline system includes a second air three-way valve 10, a first air pipe 11, a second air pipe 12, a third air pipe 13, and a sealing joint 14. The first air pipe 11 connects the second air three-way valve 10 and the first air three-way valve 9. The second air pipe 12 connects the second air three-way valve 10 and the positive pressure interface of the differential pressure transmitter 2. The third air pipe 13 connects the second air three-way valve 10 and the sealing joint 14. In this embodiment, it also includes a first ball valve 15 and a second ball valve 16. The first ball valve 15 connects the sealing joint 14 and the positive pressure measuring rod 3, and the second ball valve 16 is installed on the third air pipe 13. In this embodiment, the upper ends of the positive pressure guide rod 4 and the heating jacket pipe 5 are welded to the first ball valve 15, and the sealing joint 14 is welded to the first ball valve 15. One end of the positive pressure measuring rod 3 passes through and is welded to the third gas pipe 13. The other end of the positive pressure measuring rod 3 passes through the sealing joint 14, the first ball valve 15, and the positive pressure guide rod 4 and enters the reactor to contact the medium being measured to measure the liquid level. The gas after being diverted by the first gas path three-way valve 9 can enter the second gas path three-way valve 10 through the first gas pipe 11, and then enter the differential pressure transmitter 2 through the second gas pipe 12. Part of the gas enters the sealing joint 14 through the third gas pipe 13, and then enters the first ball valve 15 through the sealing joint 14, and then enters the positive pressure measuring rod 3 for measurement.

[0027] Furthermore, as a preferred embodiment, the negative pressure pipeline system includes a fourth gas pipe 17, a fifth gas pipe 18, a sixth gas pipe 19, a third gas path three-way valve 20, and a fourth gas path three-way valve 21. The fourth gas pipe 17 connects the third gas path three-way valve 20 and the first gas path three-way valve 9. The fifth gas pipe 18 connects the third gas path three-way valve 20 and the negative pressure interface of the differential pressure transmitter 2. The sixth gas pipe 19 connects the third gas path three-way valve 20 and the fourth gas path three-way valve 21. This embodiment also includes a third ball valve 22, a fourth ball valve 23, and a fifth ball valve 24. The sixth gas pipe 19 is equipped with the third ball valve 22. The fourth ball valve 23 and the fifth ball valve 24 are respectively connected to the fourth gas path three-way valve 21. The negative pressure measuring rod is connected to the fifth ball valve 24. In this embodiment, the structure of the negative pressure guiding rod 8 of the positive pressure guiding rod 4 is the same, and the structure of the negative pressure measuring rod is the same as that of the positive pressure measuring rod 3. The lower end of the negative pressure guiding rod 8 can also penetrate the measuring flange 7, and is not limited to... Figure 1The state shown is as follows. The negative pressure guide rod 8 is welded to the measuring flange 7, and the upper end of the negative pressure guide rod 8 is welded to the fifth ball valve 24. The fifth ball valve 24 and the fourth ball valve 23 are respectively welded to the fourth gas path three-way valve 21 via pipelines. One end of the negative pressure measuring rod is welded to the fifth ball valve 24, and the other end of the negative pressure measuring rod passes through the negative pressure guide rod 8 and enters the reactor, but does not contact the medium inside the reactor.

[0028] By controlling the opening or closing state of the fourth ball valve 23, the transmission path and intensity of the negative pressure signal can be precisely adjusted. When it is necessary to simulate specific working conditions or adjust the measurement sensitivity of the liquid level measurement, the operator can flexibly adjust the opening of the fourth ball valve according to actual needs. For example, when the liquid level in the reactor changes within a large range and more precise measurement is required, the opening of the fourth ball valve can be appropriately adjusted to optimize the pressure distribution within the negative pressure pipeline system, so that the negative pressure signal received by the differential pressure transmitter 2 more accurately reflects the liquid level change, thereby improving the accuracy of the liquid level measurement.

[0029] In this embodiment, the first air tube 11, the second air tube 12, the third air tube 13, the fourth air tube 17, the fifth air tube 18, the sixth air tube 19, the positive pressure measuring rod 3, the positive pressure guide rod 4, the negative pressure measuring rod, and the negative pressure guide rod 8 are all made of stainless steel.

[0030] In operation, the gas is depressurized by pressure reducing valve 1, then split into two paths by first gas path three-way valve 9. One path enters first gas pipe 11, and the other enters fourth gas pipe 17. The gas in first gas pipe 11 passes through second gas path three-way valve 10 and finally enters the positive pressure port and positive pressure measuring rod 3 of differential pressure transmitter 2, and then enters the reaction vessel for measurement via positive pressure measuring rod 3. Meanwhile, the gas in fourth gas pipe 17 passes through third gas path three-way valve 20 and finally enters the negative pressure port and negative pressure measuring rod of differential pressure transmitter 2, and then enters the reaction vessel for measurement via negative pressure measuring rod.

[0031] For the positive pressure side, gas enters the positive pressure port and positive pressure measuring rod 3 of differential pressure transmitter 2. When the liquid level in the reactor rises, the back pressure generated by the gas increases, and the gas pressure at the positive pressure port of differential pressure transmitter 2 also increases simultaneously. The pressure at the positive pressure port of differential pressure transmitter 2 is ΔP1. For the negative pressure side, gas enters the negative pressure port and negative pressure measuring rod of differential pressure transmitter 2. Under process control, the pressure in the reactor changes, and the back pressure generated by the gas also changes. The gas pressure at the negative pressure port of differential pressure transmitter 2 also changes simultaneously, and the pressure at the negative pressure port of differential pressure transmitter 2 is ΔP2. The positive and negative differential pressure values ​​of differential pressure transmitter 2 are ΔP, which is equal to the positive pressure side pressure ΔP1 minus the negative pressure side pressure ΔP2, i.e., ΔP = ΔP1 - ΔP2. The liquid level in the reactor is measured as h, the density of the medium is ρ, and the acceleration due to gravity is g. The liquid level is calculated using the formula h = ΔP / (ρ*g). A higher differential pressure in the reactor results in a higher liquid level, and a lower differential pressure results in a lower liquid level. The differential pressure value is converted into an analog signal of 4-20mA and transmitted to an external display system (monitor) to show the liquid level in the reactor.

[0032] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A liquid level measuring device, characterized in that, The device includes a pressure reducing valve, a positive pressure pipeline system, a negative pressure pipeline system, a differential pressure transmitter, a positive pressure measuring rod, a negative pressure measuring rod, a positive pressure guide rod, a heat tracing jacket, and heat tracing flanges. The pressure reducing valve connects the positive pressure pipeline system and the negative pressure pipeline system. The positive pressure pipeline system connects the differential pressure transmitter and the positive pressure measuring rod. The positive pressure guide rod is sleeved on the outer side of the positive pressure measuring rod. The heat tracing jacket is sleeved on the outer side of the positive pressure guide rod. Two heat tracing flanges are provided on one side of the heat tracing jacket. The negative pressure pipeline system connects the differential pressure transmitter and the negative pressure measuring rod.

2. The liquid level measuring device as described in claim 1, characterized in that, It also includes a measuring flange and a negative pressure guide rod, the negative pressure guide rod being sleeved on the outside of the negative pressure measuring rod, the positive pressure guide rod and the negative pressure guide rod both penetrating the measuring flange, and one end of the heat tracing jacket tube being connected to the measuring flange.

3. The liquid level measuring device as described in claim 1, characterized in that, The two heat tracing flanges are connected to the heat tracing jacket pipe via connecting rods.

4. The liquid level measuring device as described in claim 1, characterized in that, It also includes a first air passage three-way valve, and the pressure reducing valve is connected to the positive pressure pipeline system and the negative pressure pipeline system through the first air passage three-way valve.

5. The liquid level measuring device as described in claim 4, characterized in that, The positive pressure pipeline system includes a second air three-way valve, a first air pipe, a second air pipe, a third air pipe, and a sealing joint. The first air pipe connects the second air three-way valve and the first air three-way valve. The second air pipe connects the second air three-way valve and the positive pressure interface of the differential pressure transmitter. The third air pipe connects the second air three-way valve and the sealing joint.

6. The liquid level measuring device as described in claim 5, characterized in that, It also includes a first ball valve and a second ball valve, the first ball valve being connected to the sealing joint and the positive pressure measuring rod, and the second ball valve being installed on the third air pipe.

7. The liquid level measuring device as described in claim 4, characterized in that, The negative pressure pipeline system includes a fourth gas pipe, a fifth gas pipe, a sixth gas pipe, a third gas three-way valve, and a fourth gas three-way valve. The fourth gas pipe connects the third gas three-way valve and the first gas three-way valve. The fifth gas pipe connects the third gas three-way valve and the negative pressure interface of the differential pressure transmitter. The sixth gas pipe connects the third gas three-way valve and the fourth gas three-way valve.

8. The liquid level measuring device as described in claim 7, characterized in that, It also includes a third ball valve, a fourth ball valve, and a fifth ball valve. The sixth air pipe is equipped with the third ball valve. The fourth ball valve and the fifth ball valve are respectively connected to the fourth air passage three-way valve. The negative pressure measuring rod is connected to the fifth ball valve.

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