A bypass pipe structure for measuring the liquid level of a tar fraction column

Abstract

The utility model relates to a technical field of chemical equipment, concretely relates to a bypass pipe structure for measuring tar fraction tower liquid level to solve the problem that the internal filling liquid volume of double flange differential pressure transmitter expands under the influence of high temperature, damages the instrument, tar is easy to condense and block, and influences the measurement accuracy. The device is provided with first and second interfaces between the fraction tower and the bypass pipe, so that the liquid level height is the same, the radar liquid level meter is not affected by high temperature for accurate measurement by using the heat insulation plate, the bypass pipe blocks the fraction tower and the differential pressure transmitter, the filling liquid in the capillary is not affected by high temperature, volume expansion does not cause deformation, and the instrument is not damaged, the first and second ball valves and the bypass pipe are made of high-temperature-resistant heat preservation materials, cooperate with the steam blowing of the steam purging device, can effectively prevent tar from condensing and blocking in the bypass pipe, the radar liquid level meter and the differential pressure transmitter verify each other, form multiple measurement guarantees, and avoid the problem of inaccurate measurement.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically to a bypass pipe structure for measuring the liquid level of a tar distillation tower. Background Technology

[0002] Coal tar is a black, viscous liquid with a pungent odor, produced during the dry distillation of coal. It is characterized by high viscosity, strong corrosiveness, and a tendency to crystallize. Coal tar is generally used as a raw material for refining various chemical products. A fractionation column is a crucial piece of equipment in the coal tar distillation process, separating the coal tar mixture by utilizing the differences in boiling points of its components. Through steps such as heating and vaporization, fractionation and purification, condensation and reflux, and collection and discharge, it achieves separation of the coal tar mixture. It is typically separated into six fractions: light oil, phenolic oil, naphthalene oil, wash oil, anthracene oil, and bitumen. The fractionation column can provide us with various pure chemical products. The liquid level in the distillation column is a crucial operational indicator in distillation production. Poor control can lead to the complete shutdown of the coal tar distillation process. Fluctuations in the distillation column level directly affect the distillation effect and product quality. Therefore, controlling the liquid level in the distillation column is paramount, necessitating the use of measuring devices. However, existing coal tar distillation column level measuring devices have several problems and defects: Traditional measurement methods use only a single dual-flange differential pressure level gauge. Due to the high temperature inside the distillation column, prolonged operation at high temperatures causes the volume of the filling liquid in the flange diaphragm box to expand, resulting in bulging of the diaphragm and even permanent deformation, failing to accurately reflect the actual liquid level in a timely manner. Traditional coal tar distillation column level measuring devices cannot prevent condensation and blockage of the measured medium, failing to ensure media flow and hindering normal measurement. Furthermore, traditional coal tar distillation column level measuring devices cannot provide multiple measurement safeguards and cannot meet the requirements for long-term stable, reliable, and accurate measurement. Utility Model Content

[0003] This invention provides a bypass pipe structure for measuring the liquid level of a tar distillation tower, in order to solve the problems of internal liquid volume expansion in dual-flange differential pressure transmitters under high temperature, which damages the instrument, and tar condensation and blockage, affecting measurement accuracy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A bypass pipe structure for measuring the liquid level of a tar distillation tower includes a distillation tower, a bypass pipe connected to the side of the distillation tower, a heat insulation plate at the top of the bypass pipe, a radar level gauge at the top of the heat insulation plate, a first flange diaphragm box and a second flange diaphragm box on the side of the bypass pipe, a capillary tube connected between the first flange diaphragm box and the second flange diaphragm box, and a dual-flange differential pressure transmitter connected to the capillary tube.

[0005] Furthermore, the bottom of the distillation tower is provided with a first interface and a second interface, and the pipes connecting the first interface and the second interface to the bypass pipe are provided with a first ball valve and a second ball valve.

[0006] Furthermore, a steam purger is provided at the top of the bypass pipe, and a mounting flange is provided at the top of the steam purger, with an insulation plate inclined inside the mounting flange.

[0007] Furthermore, a steam pipe is connected to the side of the steam purger, and a shut-off valve is installed on the steam pipe.

[0008] Furthermore, a blind plug can be detachably installed at the bottom of the bypass pipe.

[0009] Furthermore, the insulation board is made of high-molecular polymer material, which can withstand high temperatures of 980℃, and the insulation board is installed inside the mounting flange at a 45° angle.

[0010] Furthermore, both the first ball valve and the second ball valve are insulated jacketed ball valves.

[0011] Furthermore, the bypass pipe is an integral jacketed bypass pipe, and the measured medium temperature can reach up to 400℃.

[0012] Furthermore, the steam purger 4 airflow outlet adopts an inline nozzle design.

[0013] Furthermore, the radar level gauge uses the ULS81 high-temperature radar level gauge.

[0014] Furthermore, the dual-flange differential pressure transmitter uses the FMD78-1AC7F22B33AA intelligent dual-flange diaphragm-sealed differential pressure transmitter.

[0015] This utility model has the following beneficial effects: By opening a first and second interface in the distillation column, tar enters the bypass pipe, forming tar at the same level for radar level gauge measurement. The installation of a high-polymer insulation plate inside the flange prevents the radar level gauge from being affected by high temperatures, thus ensuring accurate level measurement. The bypass pipe effectively isolates the distillation column and the dual-flange differential pressure transmitter, preventing deformation of the diaphragm due to high-temperature volume expansion of the filling liquid in the capillary of the dual-flange differential pressure transmitter. This ensures long-term accuracy of level measurement data and significantly extends the instrument's service life. The first ball valve, second ball valve, and bypass... All pipes are made of high-temperature resistant insulation material. With regular steam purging by a steam purger, tar can be effectively prevented from condensing and clogging in the bypass pipe, ensuring smooth medium flow and avoiding interruption of liquid level measurement due to blockage. This enables continuous and stable liquid level monitoring. This utility model adopts two measurement methods: a radar level gauge and a dual-flange differential pressure transmitter. The two methods verify each other, forming multiple measurement guarantees. It can meet the requirements of long-term stable, reliable, and accurate liquid level measurement under complex working conditions such as high viscosity, strong corrosion, and high temperature in coal tar distillation towers, avoiding the production risks caused by the failure of a single measurement method. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] The meanings of the reference numerals in the attached figures are as follows: 1. Radar level gauge; 2. Mounting flange; 3. Heat insulation plate; 4. Steam purger; 5. First ball valve; 6. Second ball valve; 7. Bypass pipe; 8. Blind plug; 9. First flange diaphragm box; 10. Second flange diaphragm box; 11. Dual-flange differential pressure transmitter; 12. Capillary tube; 13. Steam pipe; 14. Shut-off valve; 15. First interface; 16. Second interface; 17. Distillation column. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, a bypass pipe structure for measuring the liquid level of a tar distillation tower includes a distillation tower 17, a bypass pipe 7 connected to the side of the distillation tower 17, a heat insulation plate 3 provided at the top of the bypass pipe 7, a radar level gauge 1 provided at the top of the heat insulation plate 3, a first flange diaphragm box 9 and a second flange diaphragm box 10 provided on the side of the bypass pipe 7, a capillary tube 12 connected between the first flange diaphragm box 9 and the second flange diaphragm box 10, and a dual flange differential pressure transmitter 11 connected to the capillary tube 12.

[0020] The bottom of the distillation tower 17 is provided with a first interface 15 and a second interface 16. The first interface 15 and the second interface 16 are connected to the bypass pipe 7 and are provided with a first ball valve 5 and a second ball valve 6.

[0021] The top of the bypass pipe 7 is equipped with a steam purger 4, the top of the steam purger 4 is equipped with a mounting flange 2, and the mounting flange 2 is inclined with a heat insulation plate 3.

[0022] The steam purger 4 is connected to a steam pipe 13 on its side, and a shut-off valve 14 is provided on the steam pipe 13.

[0023] The bottom of the bypass pipe 7 is detachably equipped with a blind plug 8.

[0024] In practical use, the first ball valve 5 and the second ball valve 6 are first opened, allowing the tar in the distillation tower 17 to enter the bypass pipe 7 through the first interface 15 and the second interface 16. Since the bottom of the distillation tower 17 and the bypass pipe 7 are at the same height, the liquid level of the tar in the distillation tower 17 and the bypass pipe 7 is the same. Since the first ball valve 5 and the second ball valve 6 are both heat-insulated jacketed ball valves, and the bypass pipe 7 is a steam-jacketed bypass pipe, the heat-insulating steam enters the heat-insulating jacket of the bypass pipe 7 through the middle connection port of the steam jacket of the first ball valve 5, and flows out from the middle connection port of the steam jacket of the second ball valve 6 in a circulation. The measured medium temperature can reach up to 400℃, possessing heat insulation and high-temperature resistance properties. Therefore, the tar in the bypass pipe 7 will not condense or become clogged, ensuring tar flow. At this time, the radar level gauge 1 at the top of the bypass pipe 7 can measure the tar level height. Simultaneously, the first flange diaphragm box 9 and the second flange diaphragm box 10 on the side of the bypass pipe 7 transmit the pressure of the measured tar to the filling liquid in the capillary tube 12, and then the filling liquid transmits the pressure to the dual-flange differential pressure sensor 11. Finally, the pressure difference is converted into an electrical signal output of the tar level data, making the measurement process more reliable. This measuring instrument avoids direct contact between corrosive and viscous tar and the sensor, achieving long-term stable, reliable, and accurate measurement of the level of high-viscosity, high-temperature, and corrosive media. Furthermore, periodically opening the shut-off valve 14 to use steam to purge the lower surface of the heat insulation plate 3 can prevent oil and gas deposits from adhering to the heat insulation plate 3, avoiding the influence of oil and gas on the measurement data of the radar level gauge 1.

Claims

1. A bypass pipe structure for measuring the liquid level of a tar distillation column, comprising a distillation column (17), characterized in that: The distillation tower (17) is connected to a bypass pipe (7) on its side. The top of the bypass pipe (7) is provided with a heat insulation plate (3). The top of the heat insulation plate (3) is provided with a radar level gauge (1). The side of the bypass pipe (7) is provided with a first flange diaphragm box (9) and a second flange diaphragm box (10). A capillary tube (12) is connected between the first flange diaphragm box (9) and the second flange diaphragm box (10). A double flange differential pressure transmitter (11) is also connected to the capillary tube (12).

2. The bypass pipe structure for measuring the liquid level of a tar fractionation tower according to claim 1, characterized in that: The distillation tower (17) has a first interface (15) and a second interface (16) at the bottom. The first interface (15) and the second interface (16) are connected to the bypass pipe (7) by a first ball valve (5) and a second ball valve (6).

3. A bypass pipe structure for measuring the liquid level of a tar fractionation tower according to claim 2, characterized in that: The bypass pipe (7) is equipped with a steam purger (4) at the top, and a mounting flange (2) is provided at the top of the steam purger (4). An insulation plate (3) is inclined inside the mounting flange (2).

4. A bypass pipe structure for measuring the liquid level of a tar fractionation tower according to claim 3, characterized in that: The steam purger (4) is connected to a steam pipe (13) on its side, and a shut-off valve (14) is provided on the steam pipe (13).

5. A bypass pipe structure for measuring the liquid level of a tar fractionation tower according to claim 3, characterized in that: The bypass pipe (7) is detachably equipped with a blind plug (8) at its bottom.

Images