Radar purging waveguide device for modified asphalt liquid level measurement

Abstract

The utility model relates to the technical field of instrument measurement, in particular to a radar purging waveguide device for measuring the liquid level of modified asphalt, and aims to solve the problems that when the liquid level of the modified asphalt is measured at present, an existing measurement mode cannot overcome interference of oil gas volatilization on radar pulses, false signals are generated, and the measurement accuracy is poor. Therefore, the measurement precision and reliability are influenced. According to the device, a nitrogen purging device, a wave guide tube with a wave guide groove, a radar host and the like are adopted, the purging device is designed to be of a jacket type annular structure, an airflow outlet is designed to be of an internally tangent nozzle, industrial nitrogen is used for continuous purging through a purging inlet, a shielding air curtain is formed, and volatile oil gas is prevented from adhering and polluting a radar liquid level meter antenna; the wave guide tube with the wave guide groove overcomes the problems of low measurement accuracy and poor stability caused by scattering and absorption of microwaves by turbulence generated by liquid stirring of the asphalt storage tank in measurement of the radar liquid level meter.

Description

Technical Field

[0001] This utility model relates to the field of instrumentation and measurement technology, specifically to a radar purge waveguide device for measuring the level of modified asphalt. Background Technology

[0002] Asphalt is a viscous liquid that easily solidifies. To prevent asphalt from solidifying and coking on the inner walls of pipelines, storage tanks, and reaction vessels during production and storage, modified asphalt is continuously heated using heat transfer oil during production, transportation, and storage to maintain its temperature at around 200℃. This reduces the viscosity of the asphalt, increases its fluidity, and slows down the coking process. The high temperature, viscosity, agitation, and oil vapor volatilization characteristics of modified asphalt production pose challenges to the use of level gauges, as conventional level gauges are difficult to adapt to such harsh measurement environments. In recent years, radar level gauge technology has developed both domestically and internationally. Currently, radar level gauges are being used to measure the level of modified asphalt in China. Traditional float-type level gauges introduce errors due to the nonlinearity of the tangent function when the float's vertical movement is converted into angular displacement. The greater the level fluctuation during the agitation of the asphalt storage tank, the larger the error. Furthermore, the angular displacement sensor is prone to wear during continuous rotation, affecting its service life. Stable and reliable measurement is difficult to achieve. When using remote diaphragm-sealed differential pressure transmitters, the high temperature inside the asphalt storage tank and prolonged operation at high temperatures cause the filling liquid in the flange diaphragm box to expand, leading to bulging of the isolation diaphragm and even permanent deformation. This results in an inability to accurately reflect the actual liquid level in a timely manner, and the inability to overcome interference from oil and gas evaporation on the radar pulse, generating false signals and affecting measurement accuracy and reliability. Due to the special nature of its operating conditions, there is currently a lack of complete and reliable engineering methods for online continuous and stable measurement using radar level gauges. Therefore, selecting a suitable level detection instrument is a key factor in the safe production of modified asphalt. Utility Model Content

[0003] This invention provides a radar purge waveguide device for measuring the level of modified asphalt, in order to solve the problems mentioned above.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A radar purge waveguide device for measuring the level of modified asphalt includes an asphalt mixing tank. A waveguide is provided through one side of the top of the asphalt mixing tank. A purger is detachably connected to the top of the waveguide extending out of the top of the asphalt mixing tank. A radar level gauge is detachably connected to the top of the purger. An air source is controllably connected to the side of the purger. A multi-blade agitator is provided on the other side of the top of the asphalt mixing tank, parallel to the waveguide.

[0006] Furthermore, the bottom of the radar level gauge is provided with a mounting flange, and the top of the purger is provided with a purger upper flange, and the mounting flange and the purger upper flange are detachably connected.

[0007] Furthermore, a filter pressure reducing valve is provided at the side pipe of the purger, and the filter pressure reducing valve is connected to a shut-off valve, which is connected to the air source.

[0008] Furthermore, the bottom of the purger is provided with a purger lower flange, and the top of the waveguide is provided with a waveguide mounting flange, and the waveguide mounting flange and the purger lower flange are detachably connected.

[0009] Furthermore, the waveguide has multiple waveguide grooves evenly distributed on its side, and a vent hole is also provided on the top side of the waveguide groove.

[0010] Furthermore, a speed reducer is provided on the top of the asphalt mixing tank, and the speed reducer is connected to the multi-blade agitator.

[0011] This utility model has the following beneficial effects:

[0012] This utility model adopts a jacketed annular structure for the purger, and the airflow outlet is designed with an internal tangent nozzle (1.5mm×60°). Industrial nitrogen is used to continuously purge through the purge inlet to form a shielded air curtain to prevent volatile oil and gas from adhering and contaminating the radar level gauge antenna.

[0013] This invention solves the problem of low measurement accuracy and poor stability caused by microwave scattering and absorption due to turbulence generated by the stirring of liquid in asphalt storage tanks in radar level gauge measurement by installing a waveguide tube with a waveguide groove. It achieves the goal of ±2mm accuracy, ±5mm repeatability, and ≤1 manual maintenance per year for level measurement of turbulent containers. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] The meanings of the reference numerals in the attached figures are as follows:

[0016] 1. Radar level gauge; 2. Mounting flange; 3. Upper flange of purger; 4. Purger; 5. Lower flange of purger; 6. Waveguide mounting flange; 7. Waveguide; 8. Air source; 9. Shut-off valve; 10. Filter pressure reducing valve; 11. Waveguide groove; 12. Vent; 13. Reducer; 14. Multi-blade agitator; 15. Asphalt mixing tank. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1As shown, a radar purge waveguide device for measuring the level of modified asphalt includes an asphalt mixing tank 15. A waveguide 7 is provided through one side of the top of the asphalt mixing tank 15. A purger 4 is detachably connected to the top of the waveguide 7 extending out of the top of the asphalt mixing tank 15. A radar level gauge 1 is detachably connected to the top of the purger 4. An air source 8 is controllably connected to the side of the purger 4. A multi-blade agitator 14 is provided parallel to the waveguide 7 on the other side of the top of the asphalt mixing tank 15.

[0019] The bottom of the radar level gauge 1 is provided with a mounting flange 2, and the top of the purger 4 is provided with a purger upper flange 3. The mounting flange 2 and the purger upper flange 3 are detachably connected.

[0020] A filter pressure reducing valve 10 is provided at the side pipe of the purger 4. The filter pressure reducing valve 10 is connected to a shut-off valve 9, which is connected to the air source 8.

[0021] The bottom of the purger 4 is provided with a purger lower flange 5, and the top of the waveguide 7 is provided with a waveguide mounting flange 6. The waveguide mounting flange 6 and the purger lower flange 5 are detachably connected.

[0022] Multiple waveguide grooves 11 are evenly distributed on the side of the waveguide 7, and a vent hole 12 is also provided on the top side of the waveguide groove 11.

[0023] The top of the asphalt mixing tank 15 is equipped with a speed reducer 13, and the speed reducer 13 is connected to the multi-blade agitator 14.

[0024] In practical applications, the purger 4 is a jacketed annular structure with an internally tangential nozzle (1.5mm × 60°) at the air outlet. It uses 0.2-0.3MPa industrial nitrogen gas for continuous purging through the purge inlet, forming a shielding air curtain to prevent oil, gas, and other contaminants from adhering to the radar level gauge antenna. The air filter pressure reducing valve 10 has a maximum working pressure of 1MPa, a filtration accuracy of 5μm, and a pressure adjustment range of 0.1-0.5MPa. The air filter pressure reducing valve 10 filters particles >5μm from the nitrogen or compressed air source and reduces the pressure to 0.2-0.3MPa. The inlet shut-off valve 9 of the air source 8 has a maximum withstand pressure of 1.6MPa and can be used to cut off the pressure source during maintenance or replacement of the air filter pressure reducing valve 10. The purge air must be dry and clean.

[0025] The waveguide 7 has two rows of waveguide grooves 11 with an included angle of 180°. The window-shaped openings of the waveguide grooves 11 realize the smooth transition of the turbulent eddy liquid surface, so that the measured medium, asphalt liquid, will not produce abrupt changes or discontinuities. The lower end of the waveguide 7 is cut at a 45° angle to ensure the normal flow of the asphalt liquid. Vent holes 12 are opened in the blind zone of the waveguide 7 to ensure the pressure balance inside and outside the waveguide.

Claims

1. A radar purge waveguide device for measuring the level of modified asphalt, comprising an asphalt mixing tank (15), characterized in that: the asphalt... A waveguide (7) is provided through one side of the top of the mixing tank (15). A purger (4) is detachably connected to the top of the asphalt mixing tank (15). A radar level gauge (1) is detachably connected to the top of the purger (4). An air source (8) is controllably connected to the side of the purger (4). A multi-blade agitator (14) is provided on the other side of the top of the asphalt mixing tank (15) and parallel to the waveguide (7).

2. The radar purge waveguide device for measuring modified asphalt level according to claim 1, characterized in that: The bottom of the radar level gauge (1) is provided with a mounting flange (2), and the top of the purger (4) is provided with a purger upper flange (3), and the mounting flange (2) and the purger upper flange (3) are detachably connected.

3. The radar purge waveguide device for measuring modified asphalt level according to claim 2, characterized in that: The purger (4) has a filter pressure reducing valve (10) on its side pipe. The filter pressure reducing valve (10) is connected to a shut-off valve (9), which is connected to the air source (8).

4. The radar purge waveguide device for measuring modified asphalt level according to claim 3, characterized in that: The bottom of the purger (4) is provided with a purger lower flange (5), and the top of the waveguide (7) is provided with a waveguide mounting flange (6), and the waveguide mounting flange (6) and the purger lower flange (5) are detachably connected.

5. A radar purge waveguide device for measuring modified asphalt level according to claim 4, characterized in that: The waveguide (7) has multiple waveguide grooves (11) evenly distributed on its side, and a vent hole (12) is also provided on the top side of the waveguide groove (11).

6. The radar purge waveguide device for measuring modified asphalt level according to claim 1, characterized in that: The top of the asphalt mixing tank (15) is equipped with a speed reducer (13), and the speed reducer (13) is connected to the multi-blade agitator (14).

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