A radar waveguide device suitable for foam and turbulent eddy current level detection

Abstract

The present invention relates to the field of instrument measurement technology, and in particular to a radar waveguide device suitable for foam and turbulent eddy current liquid level detection. It aims to solve the current problems of low measurement accuracy, poor stability and high maintenance requirements caused by the turbulence of the liquid and the scattering and absorption of microwaves by foam when using microwave level meters to measure the height of liquid media in domestic foam and high turbulence media containers. The microwave level meter of the device emits microwaves, which are partially absorbed and partially reflected back when encountering a microwave reflector. The liquid level is measured by measuring the set parameter relationship between the transmitted wave and the reflected wave and the various operating spectrum diagrams of the microwave level meter. The present invention can effectively improve the problems of low accuracy and poor stability of various traditional static level meters when measuring media such as foam and turbulent eddy current levels, and has good practical application value.

Description

Technical Field

[0001] The present invention relates to the technical field of instrument measurement, and in particular to a radar waveguide device suitable for foam and turbulent eddy current liquid level detection. Background Art

[0002] While liquid levels in material containers in modern industrial production processes can be accurately measured, continuous measurement of the liquid level in foam media remains challenging. This presents a unique and challenging problem not only in China but also internationally. As is well known, foam is composed of numerous bubbles of irregular shapes and sizes. The upper layers are larger, while the lower layers decrease in volume due to weight. Consequently, the overall density of the foam varies and is extremely unstable. Therefore, commonly used level gauges, such as static pressure level gauges, buoyancy level gauges, capacitance level gauges, and nuclear radiation level gauges, are incapable of solving the foam level measurement challenge. For decades, measuring the liquid level in foam and high-turbulence containers has been a challenge for the industry. In recent years, radar level gauges have become widely used in industrial instrumentation to measure liquid media levels. They offer non-contact measurement, require no displacement or transmission components, and are unaffected by temperature, pressure, steam, or aerosol restrictions. However, in many major industries such as chemical industry, mineral flotation, biopharmaceuticals, and sewage treatment, the process steps in the production process always encounter the situation where a large amount of suspended foam is generated by the materials. The foam has a scattering and absorption effect on microwaves, which will attenuate the microwave signal and thus affect the normal measurement of the radar level meter. In addition, when the liquid level of the measured medium has a turbulent eddy surface due to mechanical stirring or the action of material feeding and discharging, it will not only cause the absorption and scattering of microwaves, but also cause the refraction and reflection of electromagnetic waves, greatly attenuating the intensity of the reflected echo, seriously affecting the accurate measurement of the radar level meter. In the existing technology, there is still no reliable, stable and targeted special device and method for measuring the liquid level of foam and high turbulence containers. Summary of the Invention

[0003] The present invention provides a radar waveguide device suitable for foam and turbulent eddy current liquid level detection. Its purpose is to solve the problems of low measurement accuracy and poor stability caused by the scattering and absorption of microwaves by liquid turbulence and foam when using microwave level meters to measure the liquid medium level in the existing technology.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A radar waveguide device suitable for foam and turbulent eddy current liquid level detection includes a microwave level meter, an angular bracket is provided at the bottom of the microwave level meter, the bottom of the angular bracket is connected to a mounting cylinder, a water retaining pipe is provided in the mounting cylinder, a cylindrical overflow water scrubber is formed between the water retaining pipe and the mounting cylinder, and the overflow water scrubber is connected to a water source. A waveguide is detachably installed on the inner side of the bottom of the mounting cylinder, and a waveguide groove is provided on the waveguide. A microwave reflector is provided inside the mounting cylinder, and a slide rod is provided at the bottom of the microwave reflector. A hollow float is also provided at the bottom of the slide rod.

[0006] Furthermore, a cylindrical jet water scrubber is provided inside the installation cylinder, the cylindrical jet water scrubber is connected to a water source, and the cylindrical jet water scrubber is fixedly installed around the sliding rod.

[0007] Furthermore, the water source is connected from the outside of the installation cylinder, and industrial water with a pressure of 0.2 to 0.5 MPa is connected to the water source inlet pressure reducing valve. The outlet pipe of the pressure reducing valve is connected to the water filter, and the outlet pipe of the water filter is respectively connected to the water source pressure inlet of the pressure gauge, the cylindrical jet water scrubber, and the cylindrical overflow water scrubber.

[0008] Furthermore, the waveguide grooves are arranged side by side on the waveguide tube at a 180° angle. The waveguide groove width or hole diameter is a maximum of 1 / 10 of the tube diameter, and burrs are removed. The interior of the waveguide tube must be smooth (average roughness Rz ≤ 6.3 μm) and made of seamless stainless steel. The waveguide tube can be extended by welding flanges or sleeves, and the flange and tube can be precisely adjusted internally.

[0009] Furthermore, a mounting flange is welded to the bottom of the angle bracket, and the mounting flange is welded and fixed to the mounting cylinder.

[0010] Furthermore, a split flange is provided between the mounting cylinder and the waveguide, and the mounting cylinder and the waveguide are connected via the split flange.

[0011] Furthermore, the bottom end of the waveguide is in a closed state.

[0012] The present invention has the following beneficial effects:

[0013] This invention provides a radar waveguide device suitable for foam and turbulent eddy current liquid level detection. It eliminates the low measurement accuracy and poor stability caused by liquid turbulence and foam scattering and absorption of microwaves in microwave level measurement technology. It achieves a liquid level measurement range of less than ±15mm and repeatability within ±5mm for foam and high-turbulence containers, with less than one maintenance visit per year.

[0014] A cylindrical jet water scrubber and a cylindrical overflow water scrubber are provided inside the waveguide. The cylindrical jet water scrubber is used to support and clean the slide rod, thereby keeping the slide rod and hollow float clean and reducing dynamic friction resistance. The water outlet of the cylindrical overflow water scrubber adopts an overflow backwashing method, which can make the inside of the waveguide smooth and eliminate medium adhesion and deposition.

[0015] The waveguide tube has two rows of waveguide grooves with an angle of 180 degrees. The window-shaped openings of the waveguide grooves can eliminate a large amount of suspended foam and the turbulent eddy current to achieve a smooth transition of the liquid surface, so that the measured medium liquid will not produce step changes or discontinuities.

[0016] This invention has extensive application value and product extension value. If the product chain of technical methods + modular instruments and devices is adopted to form market products, it can bring significant economic benefits to enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a structural schematic diagram of a radar waveguide device suitable for foam and turbulent eddy current level detection.

[0018] The meanings of the reference numerals are as follows:

[0019] 1. Microwave level gauge; 2. Angle bracket; 3. Mounting flange; 4. Cylindrical jet water scrubber; 5. Cylindrical overflow water scrubber; 6. Waveguide; 7. Microwave reflector; 8. Slide rod; 9. Hollow float; 10. Waveguide trough; 11. Water source; 12. Pressure reducing valve; 13. Water filter; 14. Pressure gauge; 15. Split flange; 16. Mounting cylinder; 17. Water retaining pipe. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, a radar waveguide device suitable for foam and turbulent eddy current level detection includes a microwave level meter 1, an angle bracket 2 is provided at the bottom of the microwave level meter 1, a mounting flange 3 is welded to the bottom of the angle bracket 2, and a mounting cylinder 16 is welded to the mounting flange 3. A water retaining pipe 17 is welded and fixed inside the mounting cylinder 16, and a cylindrical overflow water scrubber 5 is formed between the water retaining pipe 17 and the mounting cylinder 16. The cylindrical overflow water scrubber 5 is connected to the water inlet pipe of the water source 11, and the cylindrical overflow water scrubber 5 discharges water by overflowing from the top opening. A split flange 15 is also provided at the bottom of the mounting cylinder 16, and the mounting cylinder 16 is connected to the waveguide 6 via the split flange 15.

[0022] A waveguide 6 is installed at the bottom of the installation cylinder 16. The waveguide 6 is provided with a waveguide groove 10. The waveguide grooves 10 are arranged side by side at an angle of 180 degrees on the waveguide 6. The bottom end of the waveguide 6 is in a closed state.

[0023] A microwave reflector 7 is installed inside the mounting cylinder 16. A slide bar 8 is located at the bottom of the microwave reflector 7, and a hollow float 9 is also located at the bottom of the slide bar 8. A water source 11 is located outside the mounting cylinder 16. A pressure reducing valve 12, a water filter 13, and a pressure gauge 14 are installed along the flow path of the water. A cylindrical jet scrubber 4 is also installed inside the mounting cylinder 16. This jet scrubber 4 is connected to the water inlet pipe of the water source 11 and is fixed around the slide bar 8. It sprays water from the bottom.

[0024] The present invention operates as follows: the entire device is secured to the top of the liquid container to be measured via mounting flange 3. The vertical end of angle bracket 2 is secured to mounting flange 3. The microwave level meter 1 is placed above waveguide 6 and vertically secured to the horizontal end of angle bracket 2. The horn antenna of microwave level meter 1 emits microwaves downward. When the microwaves encounter microwave reflector 7, they are partially absorbed and partially reflected. Liquid level measurement is achieved by measuring the relationship between the set parameters of the transmitted and reflected waves.

[0025] During the above-mentioned measurement process, flushing water is continuously introduced into the water inlet pipe of the water source 11, the opening of the water inlet pressure reducing valve 12 is adjusted, and the indicated pressure of the pressure gauge 14 is observed to keep the water inlet pressure at 0.2 MPa. The water outlet of the cylindrical jet water washer 4 and the cylindrical overflow water washer 5 are used for washing to ensure that the slide rod 8 and the hollow float 9 are always kept clean during the measurement process and are not affected by the detection solution medium.

[0026] By viewing various spectrum graphs during device operation, interference signals generated by various obstacles in the radar's microwave transmission path, such as the mounting flange 3, cylindrical jet scrubber 4, cylindrical overflow scrubber 5, and water pipes, are removed using the null spectrum. Once all debugging and operation are normal, the current value signal displayed on microwave level meter 1 is sent to the control room display instrument or PLC for continuous and accurate measurement.

Claims

1. A radar waveguide device suitable for foam and turbulent eddy current level detection, characterized by: The microwave level meter (1) comprises an angular bracket (2) at the bottom of the microwave level meter (1), a mounting cylinder (16) is connected to the bottom of the angular bracket (2), a water retaining pipe (17) is provided in the mounting cylinder (16), a cylindrical overflow type water washer (5) is formed between the water retaining pipe (17) and the mounting cylinder (16), the cylindrical overflow type water washer (5) is connected to a water source (11), a waveguide (6) is detachably mounted on the inner side of the bottom of the mounting cylinder (16), a waveguide groove (10) is provided on the waveguide (6), and the waveguide groove (10) is parallel to the waveguide (6). The microwave reflector (7) is arranged at an angle of 180 degrees. A microwave reflector (7) is provided inside the installation cylinder (16). A slide bar (8) is provided at the bottom of the microwave reflector (7). A hollow float (9) is also provided at the bottom of the slide bar (8). A cylindrical jet water scrubber (4) is also provided inside the installation cylinder (16). The cylindrical jet water scrubber (4) is connected to a water source (11), and the cylindrical jet water scrubber (4) is fixed around the slide bar (8). A mounting flange (3) is welded to the bottom of the angle bracket (2), and the mounting flange (3) is welded and fixed to the installation cylinder (16).

2. The radar waveguide device for foam and turbulent eddy current level detection according to claim 1, characterized in that: A water source (11) is also provided outside the installation cylinder (16), and a pressure reducing valve (12), a water filter (13), and a pressure gauge (14) are sequentially installed in the water source (11) pipeline along the water flow direction.

3. The radar waveguide device for foam and turbulent eddy current level detection according to claim 2, characterized in that: The mounting cylinder (16) and the waveguide (6) are connected via a split flange (15).

4. The radar waveguide device for foam and turbulent eddy current level detection according to claim 3 is characterized by: The bottom end of the waveguide (6) is in a closed state.

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