Capacitive electric contact water level gauge

Abstract

The utility model discloses a capacitive electric contact water level gauge which comprises a barrel, an electrode holder, a composite ceramic shell, a sealing ring, a gland, an electrode core rod and a transmitter shell, and an electrode mounting hole is formed in the side wall of the barrel; the electrode holder is fixed in the electrode mounting hole, and a thread or clamping groove structure is arranged on the inner wall of the electrode holder; the composite ceramic shell is inserted into the electrode holder and is in sealed connection with the electrode holder through a thread or a clamping groove; the sealing ring is nested between the electrode holder and the joint surface of the composite ceramic shell; the gland is fastened at the top of the electrode holder through a bolt or a thread to axially press the composite ceramic shell; the electrode core rod longitudinally penetrates through the composite ceramic shell and is electrically connected with the composite ceramic shell through a wire. According to the utility model, double sealing (mechanical and elastic sealing) is formed through threaded / clamping groove connection of the electrode holder and the composite ceramic shell, elastic compensation of the sealing ring and axial compression of the gland, so that the leakproof performance in high-pressure and high-temperature environments is remarkably improved, and the risk of medium leakage is avoided.

Description

Technical Field

[0001] This utility model relates to the field of water level gauge technology, and in particular to a capacitive electric contact water level gauge. Background Technology

[0002] In practical industrial applications, the types and properties of liquid media vary, leading to different requirements for liquid level measurement. Capacitive electrical contact level gauges can be flexibly configured and adjusted according to different dielectric constants and measurement environments to meet the needs of various application scenarios. Traditional liquid level measurement methods have many shortcomings in terms of accuracy, stability, and service life, while capacitive electrical contact level gauge technology effectively solves these problems by introducing advanced capacitance measurement technology and data processing algorithms.

[0003] Known technologies:

[0004] The capacitive contact water level gauge uses cylindrical capacitance measurement technology and uses the difference in dielectric constant between water vapor and steam to determine whether each electrode is on the water side or the steam side.

[0005] The capacitive contact water level gauge utilizes capacitance-to-digital conversion technology. Through a dedicated capacitance measurement chip PCap, the measurement results are transmitted to a microcontroller via an SPI communication interface. After data processing, the water level signal is output through a D / A converter chip AD.

[0006] defect:

[0007] The process is cumbersome: Capacitive contact water level gauges require temperature compensation of the medium during measurement to ensure accuracy. However, temperature compensation is complex and requires significant manpower and time, increasing operating costs and maintenance difficulty.

[0008] Small capacity: Capacitive contact level gauges have a small wiring capacity, which may not meet the needs of certain special applications. In addition, incorrect wiring may lead to distorted measurement data or equipment damage. Utility Model Content

[0009] The technical solution of this utility model to solve the above-mentioned technical problems is to provide a capacitive electric contact water level gauge, comprising:

[0010] The cylindrical body has electrode mounting holes on its side wall;

[0011] An electrode holder is fixed inside the electrode mounting hole, and its inner wall is provided with a threaded or slotted structure.

[0012] The composite ceramic housing is inserted into the electrode holder and is sealed to the electrode holder by threads or slots, and is made of high-purity alumina ceramic.

[0013] A sealing ring, nested between the electrode holder and the joint surface of the composite ceramic shell, is made of polytetrafluoroethylene or metal winding material;

[0014] The pressure cap is fastened to the top of the electrode holder by bolts or threads, thus axially pressing the composite ceramic housing;

[0015] An electrode core rod extends longitudinally through the composite ceramic shell, with its lower end extending into the interior of the cylinder and its upper end connected to a signal wire.

[0016] The transmitter housing contains a signal processing circuit inside, and a display module and alarm interface on its outer surface. It is electrically connected to the electrode core rod via wires.

[0017] Furthermore, the outer surface of the composite ceramic housing is provided with threads or protrusions that mate with the inner wall structure of the electrode holder.

[0018] Furthermore, the axial compression rate of the sealing ring is 15%-25%, and the radial interference is 0.1-0.3 mm.

[0019] Furthermore, the bottom of the pressure cap is provided with a conical pressing surface, which forms a linear contact seal with the chamfer at the top of the composite ceramic shell.

[0020] Furthermore, a high-temperature insulating adhesive layer is filled between the outer surface of the electrode core and the inner hole of the composite ceramic shell.

[0021] The technical solution of this utility model forms a double seal (mechanical + elastic seal) through the threaded / groove connection between the electrode seat and the composite ceramic shell, the elastic compensation of the sealing ring, and the axial pressing of the gland. This significantly improves the anti-leakage performance under high pressure and high temperature environments and avoids the risk of media leakage. The sealing ring is made of polytetrafluoroethylene or metal winding material, and its axial compression ratio (15%-25%) and radial interference (0.1-0.3mm) are precisely matched, which can effectively absorb the thermal expansion difference between the electrode seat and the composite ceramic shell and prevent the seal from failing under high temperature conditions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the capacitive electric contact water level gauge described in this utility model;

[0024] Figure 2 This is a cross-sectional view of the capacitive electric contact water level gauge described in this utility model.

[0025] Explanation of icon numbers:

[0026] label name label name 1 cylinder 5 Pressure cap 2 electrode holder 6 Electrode core 3 Composite ceramic shell 7 Transmitter housing 4 sealing ring Detailed Implementation

[0027] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model.

[0028] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0029] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "several" or "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0032] This utility model proposes a capacitive electric contact water level gauge, aiming to design a capacitive electric contact water level gauge.

[0033] The capacitive electric contact water level gauge proposed in this utility model will be described below in specific embodiments:

[0034] In the technical solution of this embodiment, such as Figure 1 , Figure 2 As shown, a capacitive electrical contact water level gauge includes:

[0035] The cylinder 1 has electrode mounting holes on its side wall;

[0036] Electrode holder 2 is fixed in the electrode mounting hole, and its inner wall is provided with a threaded or grooved structure.

[0037] The composite ceramic housing 3 is inserted into the electrode holder 2 and is sealed to the electrode holder 2 by threads or slots, and is made of high-purity alumina ceramic.

[0038] The sealing ring 4 is nested between the electrode base 2 and the composite ceramic shell 3, and is made of polytetrafluoroethylene or metal winding material;

[0039] The pressure cap 5 is fastened to the top of the electrode seat 2 by bolts or threads, which axially presses the composite ceramic shell 3.

[0040] The electrode core rod 6 extends longitudinally through the composite ceramic shell 3, with its lower end extending into the interior of the cylinder 1 and its upper end connected to a signal wire.

[0041] The transmitter housing 7 has a signal processing circuit inside and a display module and alarm interface on its outer surface. It is electrically connected to the electrode core rod 6 through wires.

[0042] Furthermore, the outer surface of the composite ceramic housing 3 is provided with threads or protrusions that mate with the inner wall structure of the electrode seat 2 (the protrusions are annular bosses that mate with the slots).

[0043] Furthermore, the axial compression rate of the sealing ring 4 is 15%-25%, and the radial interference is 0.1-0.3mm.

[0044] Furthermore, the bottom of the pressure cap 5 is provided with a conical pressing surface, which forms a linear contact seal with the top chamfer of the composite ceramic shell 3.

[0045] Furthermore, a high-temperature insulating adhesive layer is filled between the outer surface of the electrode core rod 6 and the inner hole of the composite ceramic shell 3.

[0046] Specifically, the dedicated chip Pcap01, based on capacitance-to-digital conversion technology, enables high-precision capacitance measurement. This chip transmits measurement results to a microcontroller via an SPI communication interface. After data processing, the result is output as a two-wire standard 4-20mA signal via the AD421 D / A converter chip. This method not only improves measurement accuracy but also simplifies circuit design. Accessing sensor measurement parameters, equipment configuration, and calibration information via a HART communication unit facilitates system debugging and maintenance. The synchronous in-situ cancellation compensation method effectively improves the technical specifications of the improved electrodes. This method uses the capacitance values ​​of each electrode under test, analyzes data to determine the variation of the water vapor dielectric constant, and obtains the minimum and maximum capacitance values ​​as a basis. Microcontroller logic programming automatically adjusts the slope of the output characteristics, thereby eliminating the influence of temperature-dependent dielectric constant variations. For issues related to small wiring capacity, miniaturized, modular junction box designs or wireless transmission technology can be considered to reduce the need for physical wiring.

[0047] It has the following technical effects:

[0048] High-precision measurement: By measuring the capacitance change of the electrodes, it can be determined whether the electrodes are on the water side or the steam side. Since there is a linear relationship between capacitance and water vapor, and the capacitance values ​​of each electrode are very close after the structural dimensions are fixed and uniform, very accurate water level measurement results can be provided.

[0049] Digital processing: The measurement results are transmitted to the microcontroller via the SPI communication interface. After data processing, the two-wire standard 4-20mA signal is output through the D / A converter chip AD421 to realize digital processing and transmission.

[0050] HART Protocol Support: The application uses the DS8500 HART modem chip, which supports the HART protocol, facilitating communication and data exchange with other devices.

[0051] Extended service life: The capacitive contact water level gauge uses composite ceramics, which has the characteristics of high temperature resistance, corrosion resistance and excellent pressure resistance. It is also designed with an axial seal to ensure long-term use without leakage.

[0052] Stability: The capacitance measurement is performed using a dedicated capacitance measurement chip PCap01 based on capacitance-to-digital conversion technology. The water vapor capacitance values ​​of the electrodes are clearly demarcated, and this technology can effectively reduce the risk of misjudgment due to contamination.

[0053] Simplified operation: The operation process is simple and convenient. Users can complete the water level measurement without complicated temperature compensation and input steps, which reduces the difficulty of operation and improves work efficiency.

[0054] Enhanced communication capabilities: By applying the HART modem chip DS8500, communication with sensors can be achieved, and information such as measurement process parameters, equipment configuration, and calibration can be accessed, thus enhancing the communication and data processing capabilities of the equipment.

[0055] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A capacitive electrical contact water level gauge, characterized in that, include: The cylindrical body has electrode mounting holes on its side wall; An electrode holder is fixed inside the electrode mounting hole, and its inner wall is provided with a threaded or slotted structure. A composite ceramic housing is inserted into the electrode holder and is sealed to the electrode holder by threads or a groove. A sealing ring is nested between the electrode holder and the joint surface of the composite ceramic shell; The pressure cap is fastened to the top of the electrode holder by bolts or threads, thus axially pressing the composite ceramic housing; An electrode core rod extends longitudinally through the composite ceramic shell, with its lower end extending into the interior of the cylinder and its upper end connected to a signal wire. The transmitter housing contains a signal processing circuit inside, and a display module and alarm interface on its outer surface. It is electrically connected to the electrode core rod via wires.

2. The capacitive electrical contact water level gauge according to claim 1, characterized in that, The outer surface of the composite ceramic housing is provided with threads or protrusions that mate with the inner wall structure of the electrode holder.

3. The capacitive electrical contact water level gauge according to claim 1, characterized in that, The axial compression rate of the sealing ring is 15%-25%, and the radial interference is 0.1-0.3 mm.

4. The capacitive electrical contact water level gauge according to claim 1, characterized in that, The bottom of the pressure cap is provided with a conical pressing surface, which forms a linear contact seal with the chamfer at the top of the composite ceramic shell.

5. The capacitive electrical contact water level gauge according to claim 1, characterized in that, A high-temperature insulating adhesive layer is filled between the outer surface of the electrode core and the inner hole of the composite ceramic shell.

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