Non-contact conductivity sensor

Abstract

The utility model relates to the technical field of conductivity detection devices, and discloses a non-contact conductivity sensor which comprises a transmitter assembly, an insulation measuring tube and electrode flanges connected with flanges at two ends of the insulation measuring tube, a through hole is formed in the middle of the transmitter assembly, and the insulation measuring tube penetrates through the through hole to be connected with the electrode flanges at the two ends. The transmitter assembly comprises a shell, a detection head and a signal cable, the detection head and the signal cable are arranged in the shell, the detection head is electrically connected with the signal cable, the other end of the signal cable is electrically connected with a display, and signals processed by the transmitter assembly are output to the display. The electrode flange is made of metal materials, wire connecting holes are formed in the electrode flange in the circumferential direction, the two ends of a wire are inserted into the wire connecting holes respectively, and the wire, the connecting flange and liquid to be measured in the insulating measuring tube form a conductive loop. According to the scheme, the conductivity of the high-temperature sulfuric acid is detected in a non-contact mode, the service life of the sensor can be prolonged, the stability of the detection result can be effectively improved, and the detection effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of conductivity detection devices, and in particular to a non-contact conductivity sensor. Background Art

[0002] High-temperature concentrated sulfuric acid is primarily found in the waste heat recovery system (HRS) of the sulfuric acid plant. In the HRS, the most important measurement point is the acid concentration at the diluter outlet, which is above 180°C. Due to the diluter's operating principle (concentrated sulfuric acid reacts with water to produce lower-concentration, more concentrated sulfuric acid, a process that releases a significant amount of heat), HRS acid concentration points are located at the heater and preheater outlets, with temperatures of 160°C and 110°C, respectively. An acid concentration meter is installed at the HRS circulating pump outlet, and temperatures at these points can reach 200°C or above. Therefore, the measured temperature of concentrated sulfuric acid in the HRS system is relatively high. The existing contact conductivity sensor has the following technical problems when measuring: (1) The existing contact conductivity sensor is in direct contact with high-temperature concentrated sulfuric acid, which can easily cause sensor distortion or even damage in long-term use; (2) When measuring the acid concentration at the diluter outlet, the presence of bubbles will also have a certain impact on the measurement of the contact conductivity sensor. The distortion or damage of the sensor will lead to inaccurate measurement of sulfuric acid conductivity, further affecting the measurement accuracy of sulfuric acid concentration; (3) Inaccurate measurement of high-temperature sulfuric acid concentration will directly lead to inaccurate PID control of the HRS system, further affecting the long-term operation of the device.

[0003] In view of this, the development of a non-contact conductivity sensor not only effectively makes up for the shortcomings of existing technologies, but also can stably measure high-temperature sulfuric acid while extending the service life of the sensor, which is of great significance to the continuity and stability of high-temperature sulfuric acid concentration detection. Summary of the Invention

[0004] The present invention aims to provide a non-contact conductivity sensor to solve the technical problem that the existing contact conductivity sensor is easily damaged when detecting high-temperature sulfuric acid concentration, resulting in fluctuations in detection results and reduced detection stability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a non-contact conductivity sensor, including a transmitter assembly, an insulating measuring tube and an electrode flange connected to the flanges at both ends of the insulating measuring tube. A through hole is provided in the middle of the transmitter assembly, and the insulating measuring tube passes through the through hole and is connected to the electrode flanges at both ends.

[0006] Preferably, as an improvement, the transmitter assembly includes a shell and a detection head and a signal cable arranged in the shell, the detection head and the signal cable are electrically connected, and the other end of the signal cable is electrically connected to a display, and the signal obtained by the transmitter assembly is output to the display.

[0007] Preferably, as an improvement, the detection head includes two groups of coils, one group serving as a transmitter and the other group serving as a receiver, and the shell completely isolates the detection head from the liquid to be detected.

[0008] Preferably, as an improvement, the electrode flange is made of metal, and a wire connection hole is provided around the electrode flange. Both ends of the wire are inserted into the wire connection holes respectively, and the wire, the connection flange and the liquid to be measured in the insulating measuring tube form a conductive loop.

[0009] Preferably, as an improvement, the transmitter assembly is also electrically connected to a temperature compensating thermistor through a wire, and the electrode flange connected to the liquid outlet end of the insulating measuring tube is connected to a liquid outlet pipe, and a recessed thermistor sleeve is provided on the liquid outlet pipe, and the thermistor of the temperature compensating thermistor is inserted into the thermistor sleeve to detect the temperature of the high-temperature sulfuric acid in the liquid outlet pipe.

[0010] Preferably, as an improvement, an insulating gasket is provided between the electrode flange and the end flange of the insulating measuring tube.

[0011] Preferably, as an improvement, a radiator is provided between the insulating measuring tube and the transmitter assembly, and a plurality of heat dissipation holes are provided on the radiator.

[0012] Preferably, as an improvement, the heat sink is a sawtooth ring, and the heat dissipation holes are arranged radially along the sawtooth ring.

[0013] Preferably, as an improvement, the inner wall of the radiator is provided with inner teeth, and the outer wall is provided with outer teeth, the inner teeth are clamped on the insulating measuring tube, and the heat dissipation holes radially pass through the top of the outer teeth.

[0014] The principle of this program:

[0015] This conductivity sensor consists of a probe, signal cable, temperature-compensating thermocouple, measuring tube, and connecting flange. The probe includes two coils: one for transmitter and the other for receiver. The housing completely isolates the probe from the liquid to be tested. When the transmitter coil is energized, sulfuric acid conducts electricity and generates an induced current proportional to its conductivity. The receiver coil detects the current, converting it into a standard signal (e.g., calculating the sulfuric acid concentration) and outputting it to a display via a signal cable. Due to the highly corrosive nature of high-temperature sulfuric acid and the inability of the insulating material to withstand high temperatures, the two coils cannot be directly immersed in sulfuric acid. Therefore, the measuring probe is mounted on a measuring tube lined with polytetrafluoroethylene. For normal operation, the electrode flanges at both ends of the sensor need to be connected with wires. When sulfuric acid flows through the measuring tube, a conductive loop is formed, allowing the sulfuric acid to generate an induced current when the transmitter coil is energized, thereby detecting the sulfuric acid conductivity.

[0016] The advantages of this solution are:

[0017] 1. Compared with the existing conductivity sensor whose probe is directly exposed to high-temperature sulfuric acid and corroded, which affects its use, this solution adopts non-contact detection of the conductivity of high-temperature sulfuric acid, which not only extends the service life of the sensor, but also effectively improves the stability of the test results and enhances the detection effect.

[0018] 2. This solution combines a transmitter assembly and a display, and connects a temperature-compensating thermistor to the liquid outlet pipe. In actual production, high-temperature sulfuric acid loses less heat when flowing in the insulated measuring tube. Therefore, connecting a temperature-compensating thermistor to the liquid outlet pipe connected to the liquid outlet can effectively detect the temperature of the high-temperature sulfuric acid. By setting up the transmitter assembly and the display, the temperature and temperature curve of the high-temperature sulfuric acid can be directly read from the display, and the real-time temperature and change trend of the high-temperature sulfuric acid can be understood, thereby performing precise PID control. The applicant found through long-term experiments that compared to connecting the temperature-compensating thermistor to the electrode flange, which causes the detected temperature to be significantly lower than the actual temperature due to severe heat loss, this solution effectively avoids excessive heat loss by connecting the temperature-compensating thermistor to the liquid outlet pipe, thereby effectively improving the accuracy of temperature detection.

[0019] 3. This solution effectively dissipates the heat emitted by the measuring tube by setting a radiator, preventing it from affecting the coil inside the transmitter assembly, thereby effectively improving the continuity and accuracy of coil detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a top view of the non-contact conductivity sensor in Example 1 of the present invention.

[0021] Figure 2 This is a front view of the non-contact conductivity sensor in Example 1 of the present invention.

[0022] Figure 3 This is a detection principle diagram of the non-contact conductivity sensor in Example 1 of the present invention.

[0023] Figure 4 This is a front view of the default transmitter assembly of the non-contact conductivity sensor in Example 2 of the present invention.

[0024] Figure 5 This is a three-dimensional diagram of the non-contact conductivity sensor in Example 2 of the present invention.

[0025] Figure 6 The present invention is a conductivity curve of high-temperature sulfuric acid obtained by detecting the obtained product using an existing contact conductivity sensor.

[0026] Figure 7 The conductivity curve of high-temperature sulfuric acid obtained by detecting the non-contact conductivity sensor of Example 2 of this solution. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementation methods:

[0028] The reference numerals in the drawings of the specification include: transmitter assembly 1, signal cable 11, temperature compensation thermal resistor 12, insulating measuring tube 2, electrode flange 3, wire connection hole 31, liquid outlet pipe 4, thermal resistor socket 41, radiator 5, heat dissipation hole 51.

[0029] Example 1

[0030] This solution provides a non-contact conductivity sensor, such as Figures 1 and 2 As shown, it includes a transmitter assembly 1, an insulating measuring tube 2, and an electrode flange 3 connected to the flanges at both ends of the insulating measuring tube 2. An insulating gasket is provided between the electrode flange 3 and the end flanges of the insulating measuring tube 2. Specifically, a through-hole is provided in the middle of the transmitter assembly 1, through which the insulating measuring tube 2 passes and is connected to the electrode flanges 3 at both ends. End flanges are fixed at both ends of the insulating measuring tube 2, and the electrode flange 3 connected to the liquid outlet end of the insulating measuring tube 2 is connected to the liquid outlet pipe 4. For reference, the electrode flange 3 is made of metal and has wire connection holes 31 circumferentially provided. The two ends of the wire are inserted into the wire connection holes 31. The wire, the connection flange, and the liquid to be measured in the insulating measuring tube 2 form a conductive circuit.

[0031] The transmitter assembly 1 includes a housing, a probe housed within the housing, and a signal cable 11. The transmitter assembly 1 is electrically connected to a temperature-compensating resistor 12 via a wire. The resistor 12 and the probe are both electrically connected to the signal cable 11. The other end of the signal cable 11 is electrically connected to a display, which outputs the processed signal from the transmitter assembly 1. Specifically, for reference, the probe in this solution includes two sets of coils: one for the transmitter and the other for the receiver. The housing completely isolates the probe from the liquid being tested.

[0032] In another embodiment, the transmitter assembly 1 further includes a narrow-sense transmission, specifically an electronic device that can convert a signal into a standard signal and output it. The narrow-sense transmitter is a prior art and will not be described in detail here. In this solution, the transmission assembly 1 is a broad-sense transmission, such as Figure 3 As shown, the system comprises a housing, two coils serving as the probe, a narrow-sense transmission for signal conversion, and a signal cable. For reference, in actual production, signal cable 11 contains seven conductors: three for connecting to temperature-compensating thermal resistor 12 to transmit temperature signals, and four for connecting to the probe to transmit conductivity signals.

[0033] The liquid outlet pipe 4 is provided with a recessed thermal resistor sleeve 41 , and the thermal resistor of the temperature compensation thermal resistor 12 is inserted into the thermal resistor sleeve 41 to detect the temperature of the high-temperature sulfuric acid in the liquid outlet pipe 4 .

[0034] The specific implementation process is as follows:

[0035] Connect the two ends of the wire to the wire connection holes 31 on the two electrode flanges 3, so that when the high-temperature sulfuric acid flows through the insulating measuring tube 2, the wire, the connection flange and the high-temperature sulfuric acid form a conductive loop. The conductive loop and the two sets of coils of the detection head are specifically as follows Figure 3 As shown in the figure, this solution uses a primary and a secondary coil installed in parallel on the same axis. The primary coil is the transmitting coil (i.e., transmitter), and the secondary coil is the receiving coil (i.e., receiver). The sensor is placed in the air. The magnetic permeability U of the magnetic ring is much greater than the magnetic permeability U0 of the air. The magnetic flux of the primary coil is basically closed through the secondary magnetic ring, and the leakage flux is very small. Therefore, there is no direct coupling between the primary coil and the secondary coil. In this way, even if current flows through the primary coil, the secondary coil cannot detect the induced current. The electrode flanges 3 at both ends are connected to the wires. If sulfuric acid passes through the short tube in the middle of the sensor (i.e., the insulated measuring tube 2), a closed loop state is presented due to the conductivity of sulfuric acid. When an alternating current passes through the primary coil, the alternating magnetic flux in the magnetic ring of the primary coil can cause the sulfuric acid to generate an alternating current. The alternating current also generates an alternating magnetic field, which in turn induces an alternating electromotive force in the secondary coil. The alternating electromotive force signal induced by the secondary coil is processed and converted by the transmitter component 1 to obtain the current conductivity of the sulfuric acid, which is then output to the display via the signal cable 11.

[0036] Similarly, the temperature is detected by the temperature compensation thermal resistor 12 to detect the temperature of the high-temperature sulfuric acid and then output to the display through the transmitter component 1 and the signal cable 11.

[0037] Example 2

[0038] In order to further improve the detection accuracy and continuity of the conductivity sensor, the difference between this embodiment and embodiment 1 is that, Figure 4 and Figure 5 As shown, a heat sink 5 is disposed between the insulated measuring tube 2 and the transmitter assembly 1. The heat sink 5 has a plurality of heat dissipation holes 51. Specifically, for reference, the heat sink 5 is a serrated ring, with the heat dissipation holes 51 radially arranged along the ring. Furthermore, the heat sink 5 has internal teeth on its inner wall and external teeth on its outer wall. The internal teeth are engaged with the insulated measuring tube 2, and the heat dissipation holes 51 extend radially through the tops of the external teeth.

[0039] In this embodiment, although the insulating measuring tube 2 dissipates less heat, this solution effectively dissipates the heat emitted by the insulating measuring tube 2 by providing a radiator 5, avoiding the heat from affecting the coil inside the transmitter assembly 1, thereby further effectively improving the continuity and accuracy of coil detection.

[0040] As a reference, in the specific implementation process, Figure 6 The conductivity curve of high-temperature sulfuric acid detected by the existing contact conductivity sensor is shown below. Figure 7 This is the conductivity curve of high-temperature sulfuric acid measured using this solution's non-contact conductivity sensor. Comparison shows that this solution's non-contact conductivity sensor provides more stable and accurate measurements of high-temperature sulfuric acid, effectively improving the accuracy of high-temperature sulfuric acid conductivity detection and enabling precise PID control.

[0041] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A non-contact conductivity sensor, characterized in that: It includes a transmitter assembly, an insulating measuring tube and electrode flanges connected to the flanges at both ends of the insulating measuring tube. A through hole is provided in the middle of the transmitter assembly, and the insulating measuring tube passes through the through hole and is connected to the electrode flanges at both ends.

2. A non-contact conductivity sensor according to claim 1, characterized in that: The transmitter assembly includes a shell, a detection head and a signal cable arranged in the shell, the detection head and the signal cable are electrically connected, and the other end of the signal cable is electrically connected to a display.

3. The non-contact conductivity sensor according to claim 2, characterized in that: The detection head includes two groups of coils, one group serves as a transmitter and the other group serves as a receiver. The shell completely isolates the detection head from the liquid to be detected.

4. The non-contact conductivity sensor according to claim 1, wherein: The electrode flange is made of metal, and a wire connection hole is provided around the electrode flange. Both ends of the wire are respectively inserted into the wire connection holes. The wire, the connection flange and the liquid to be measured in the insulating measuring tube form a conductive loop.

5. The non-contact conductivity sensor according to claim 1, characterized in that: The transmitter assembly is also electrically connected to a temperature compensation thermistor through a wire, and the electrode flange connected to the liquid outlet end of the insulating measuring tube is connected to a liquid outlet pipe. The liquid outlet pipe is provided with a recessed thermistor socket, and the thermistor of the temperature compensation thermistor is inserted into the thermistor socket to detect the temperature of the high-temperature sulfuric acid in the liquid outlet pipe.

6. The non-contact conductivity sensor according to claim 1, characterized in that: An insulating gasket is provided between the electrode flange and the end flange of the insulating measuring tube.

7. The non-contact conductivity sensor according to claim 6, characterized in that: A radiator is provided between the insulating measuring tube and the transmitter assembly, and a plurality of heat dissipation holes are opened on the radiator.

8. The non-contact conductivity sensor according to claim 7, characterized in that: The radiator is a sawtooth ring, and the heat dissipation holes are arranged along the radial direction of the sawtooth ring.

9. The non-contact conductivity sensor according to claim 8, characterized in that: The inner wall of the radiator is provided with inner teeth, and the outer wall is provided with outer teeth. The inner teeth are clamped on the measuring tube, and the heat dissipation holes radially pass through the top of the outer teeth.

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