Automatic control system for measuring liquid level of foam-containing medium by radar liquid level meter

Abstract

The utility model provides an automatic control system for a radar liquid level meter to measure the liquid level of a foam-containing medium, which comprises a degreasing tank, the radar liquid level meter is arranged at the top of the degreasing tank, the radar liquid level meter and the degreasing tank are connected through a measuring cylinder, a compressed air pipe is arranged on the side of the measuring cylinder, and the measuring cylinder and the compressed air pipe are communicated. The compressed air pipe is provided with a compressed air electric valve and a pressure regulating valve, the degreasing tank is respectively communicated with the production water pipe, the degreasing stock solution pipe and the degreasing tank, the degreasing tank is provided with a degreasing tank liquid level control valve, and the degreasing stock solution pipe is provided with a degreasing stock solution electric valve. According to the utility model, the compressed air solenoid valve is interlocked through a PLC program to defoam foams on the surface of liquid in the tank body, so that detection echoes of a radar liquid level meter effectively return to a receiving end to meet liquid level detection conditions, and the compressed air solenoid valve is automatically closed after the foams are dissipated, so that the liquid level detection efficiency is improved. And an effective means is provided for accurately measuring the liquid level of the foam-containing medium.

Description

Technical Field

[0001] This utility model belongs to the field of liquid level measurement technology, and relates to an automatic control system for measuring the liquid level of foam-containing media using a radar liquid level gauge. Background Technology

[0002] In the production of industrial stainless steel, the degreasing process is an extremely important step. The main purpose of degreasing is to remove the emulsion of rolling oil from the surface of the strip product. If the emulsion removal is not effective, it will affect the subsequent annealing process. That is, when the stainless steel strip enters the annealing furnace for annealing, black spots will form on the surface that cannot be removed, resulting in product quality defects.

[0003] The concentration of the degreasing agent and the liquid level control in the degreasing tank are interrelated throughout the entire degreasing process. Adding the degreasing agent to a suitable amount of production water in a specific ratio and heating it to 70-85℃ effectively removes grease from the surface of stainless steel strips. If the liquid level in the degreasing tank is inaccurate, it will cause the degreasing solution ratio to become uncontrolled, failing to achieve the desired degreasing effect. If the actual liquid level reaches the upper limit of the range, the tank will overflow, flooding the equipment in the pit. If the actual liquid level reaches the lower limit of the range, the external pump will run dry and burn out, causing an equipment accident. These situations can range from minor stainless steel strip quality issues to serious production interruptions. Therefore, the measurement and control of the liquid level in the degreasing tank is extremely important.

[0004] Currently, non-contact radar level gauges are used for level measurement in degreasing tanks. Since the degreasing solution is prepared in a mixing tank, after the solution is prepared, an electric valve is opened, allowing the degreasing solution to enter the degreasing tank. A certain proportion of production water is then added to obtain the appropriate degreasing solution. This degreasing solution is a type of soap agent, which generates a large amount of foam upon entering the degreasing tank. This foam forms a 20-30mm thick "barrier layer" on the liquid surface. Radar level gauges, being non-contact measuring instruments, measure liquid levels based on the echo ranging principle. The radar level gauge probe emits high-frequency pulses that propagate through space at the speed of light. When the pulse encounters the material surface, it is reflected back and received by the receiver inside the instrument, converting the distance signal into a level signal. Its working principle requires that the surface of the liquid being measured is relatively flat to ensure that the radar wave is transmitted and received vertically. If the radar wave encounters a foam "blocking layer", the effective echo will diverge, resulting in false liquid levels. False liquid levels include dead liquid levels, exceeding the upper or lower limit of the range, etc. This is because the foam on the surface of the degreasing tank is distributed in a spherical manner, causing the radar reflection echo to diverge and not return to the receiving end of the level gauge probe, causing the level gauge to "lose the signal" and fail to effectively display the actual liquid level.

[0005] Currently, the only way to prevent abnormal liquid level displays in degreasing tanks is for personnel to quickly climb to the top of the tank, open the manhole, and visually determine the actual liquid level after preparing the degreasing solution and opening the electric valve. This method increases the workload of personnel, and the accuracy of visual liquid level assessment is poor. In addition, personnel must complete this high-altitude operation in a short period of time, which poses a significant safety hazard. Utility Model Content

[0006] The purpose of this invention is to address the problems existing in the prior art by providing an automatic control system for measuring the level of foam-containing media using a radar level gauge. This system solves the problem that existing radar level gauges suffer from measurement inaccuracies due to the loss of wave amplitude caused by the instantaneous addition of degreasing liquid, which prevents them from providing accurate and stable level parameters to operators and makes it difficult to achieve precise control of the existing degreasing liquid ratio.

[0007] Therefore, the present invention adopts the following technical solution:

[0008] An automatic control system for measuring the level of foam-containing media using a radar level gauge includes a degreasing tank, which is horizontally positioned. A radar level gauge is mounted on its top and connected to the tank via a measuring cylinder. A compressed air pipe is mounted on the side of the measuring cylinder and is connected to the radar level gauge. The compressed air pipe is equipped with a compressed air electric valve and a pressure regulating valve. The degreasing tank is connected to a production water pipe, a degreasing raw material pipe, and a degreasing tank. The degreasing tank is equipped with a degreasing tank level control valve, and the degreasing raw material pipe is equipped with a degreasing raw material electric valve.

[0009] Furthermore, it also includes a PLC controller, which is electrically connected to the electric valve for the degreasing solution and the electric valve for the compressed air.

[0010] Furthermore, the degreasing tank has an opening at the location corresponding to the radar level gauge, which is connected to the measuring cylinder.

[0011] Furthermore, the compressed air pipe is U-shaped, with its opening facing the degreasing tank.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. This utility model uses compressed air to purge the liquid surface, eliminating foam generated on the liquid surface and avoiding the influence of foam on the echo divergence of the radar level gauge, thus ensuring the echo intensity of the level gauge and guaranteeing measurement accuracy.

[0014] 2. This utility model completes the preparation of degreasing solution through automatic control. Based on the degreasing effect, if the quality of the degreasing solution does not meet the standard, it can be discharged into the waste liquid pool, and the degreasing solution can be automatically prepared again.

[0015] 3. This utility model realizes the interlocking of the liquid dispensing solenoid valve and the compressed air solenoid valve, which not only ensures the accurate measurement of the liquid level in the degreasing tank, but also automatically controls the purging of compressed air, thus avoiding energy loss.

[0016] 4. This utility model can provide a more accurate basis for the degreasing solution ratio, so as to avoid the waste caused by excessively high concentration, and to avoid the problem of stainless steel product quality defects caused by insufficient degreasing due to excessively low concentration. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] In the diagram, 1-Radar level gauge, 2-Measuring cylinder, 3-Compressed air pipe, 4-Degreasing tank, 5-Compressed air electric valve, 6-Degreasing raw liquid electric valve, 7-PLC controller, 8-Pressure regulating valve, 9-Production water pipe, 10-Degreasing raw liquid pipe, 11-Degreasing tank, 12-Degreasing tank level control valve. Detailed Implementation

[0019] The technical solution of this utility model will be described below with reference to the accompanying drawings and implementation methods. Example

[0020] like Figure 1 As shown, an automatic control system for measuring the level of foam-containing media using a radar level gauge includes a degreasing tank 4, which is horizontally positioned. A radar level gauge 1 is mounted on the top of the tank, and the two are connected via a measuring cylinder 2. A compressed air pipe 3 is mounted on the side of the measuring cylinder 2, and the two are connected. Specifically, the measuring cylinder 2 refers to a guided wave radar level gauge measuring cylinder well known to those skilled in the art. Since this embodiment uses an existing guided wave radar level gauge measuring cylinder, its working principle will not be described in detail.

[0021] The compressed air pipe 3 is U-shaped, with its opening facing the degreasing tank 4. The compressed air pipe 3 is equipped with a compressed air electric valve 5 and a pressure regulating valve 8. The pressure regulating valve 8 realizes the pressure control of the compressed air, and the control range is 0.30-0.50MPa. If the foam dissipates slowly, the pressure of the pressure regulating valve can be appropriately increased. Specifically, in this embodiment, the pressure of the compressed air is set to 0.35MPa.

[0022] The degreasing tank 4 is connected to the production water pipe 9, the degreasing raw liquid pipe 10 and the degreasing tank 11 respectively. The degreasing tank 4 has an opening at the position corresponding to the radar level gauge 1, which is connected to the measuring cylinder 2. The degreasing tank 11 is equipped with a degreasing tank level control valve 12, and the degreasing raw liquid pipe 10 is equipped with a degreasing raw liquid electric valve 6.

[0023] This embodiment also includes a PLC controller 7, which is electrically connected to the degreasing liquid electric valve 6 and the compressed air electric valve 5, respectively.

[0024] The usage process of this embodiment is as follows:

[0025] When the degreasing agent solenoid valve 6 is opened by the operator, the degreasing agent and production water are injected into the degreasing tank 4 in a certain proportion. At the same time, the degreasing agent solenoid valve 6 interlocks with the compressed air electric valve 5 to open, and compressed air is introduced into the degreasing tank 4 to continuously blow away and extinguish the foam formed on the liquid level surface. After the foam dissipates, the compressed air electric valve 5 automatically closes, thus meeting the measurement conditions of the radar level gauge.

[0026] Meanwhile, the degreasing liquid in the degreasing tank 4 is pumped into the heater by the pump unit, heated to 70-85℃, and sent into the degreasing tank 11 to degrease the stainless steel strip. The liquid level control valve 12 of the degreasing tank ensures that the degreasing liquid in the degreasing tank 11 can completely soak the strip to achieve the degreasing effect.

[0027] The degreasing liquid in the degreasing tank 11 is circulated back to the degreasing tank 4 through the degreasing tank level control valve 12. When the quality of the degreasing liquid deteriorates after recycling, it is discharged into the waste liquid pool by the waste liquid discharge electric valve. The above operation is repeated. The interval between re-preparing the degreasing liquid depends on the production rhythm. In this embodiment, the interval is 6-7 hours.

Claims

1. An automatic control system for measuring the level of foam-containing media using a radar level gauge, characterized in that, The equipment includes a degreasing tank (4), which is horizontally positioned and has a radar level gauge (1) on its top. The two are connected by a measuring cylinder (2). The measuring cylinder (2) has a compressed air pipe (3) on its side, and the two are connected. The compressed air pipe (3) is equipped with a compressed air electric valve (5) and a pressure regulating valve (8). The degreasing tank (4) is connected to a production water pipe (9), a degreasing raw liquid pipe (10), and a degreasing tank (11). The degreasing tank (11) is equipped with a degreasing tank level control valve (12), and the degreasing raw liquid pipe (10) is equipped with a degreasing raw liquid electric valve (6).

2. An automatic control system for measuring the level of foam-containing media using a radar level gauge according to claim 1, characterized in that, It also includes a PLC controller (7), which is electrically connected to the degreasing liquid electric valve (6) and the compressed air electric valve (5).

3. An automatic control system for measuring the level of foam-containing media using a radar level gauge according to claim 1, characterized in that, The degreasing tank (4) has an opening at the position corresponding to the radar level gauge (1), which is connected to the measuring cylinder (2).

4. An automatic control system for measuring the level of foam-containing media using a radar level gauge according to claim 1, characterized in that, The compressed air pipe (3) is U-shaped, with its opening facing the degreasing tank (4).

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