Cathodic protection energizer for corrosion protection of reinforced concrete structures

Abstract

A cathodic protection energizing device for protecting reinforced concrete structures from corrosion includes an assembly housing, a constant voltage to constant current source circuit, and an LED display device. The constant voltage to constant current source circuit mainly consists of an adjustable positive output voltage regulator LM317T and a variable resistor R. The power input terminal in of the LM317T is connected to the positive terminal of a 30V DC power supply. The variable resistor R is connected between Vout and Vadj of the LM317T. The connection point between Vadj of the LM317T and the variable resistor R is connected to the LED display device. Simultaneously, the output terminal Iout of the cathodic protection energizing device is led out from the connection point between Vadj of the LM317T and the variable resistor R. The positive and negative connectors for the external 30V DC power supply, the output terminal Iout and the negative connector of the cathodic protection energizing device, and the LED display device are all housed within the assembly housing. This invention, while fulfilling the cathodic protection function, has a total structural cost of no more than 20 yuan, far lower than constant current power supplies of similar precision on the market.

Description

Technical Field

[0001] This utility model relates to a cathodic protection device for protecting steel bars in concrete structures from corrosion. Background Technology

[0002] In coastal environments, steel reinforcement in concrete is susceptible to electrochemical corrosion due to chloride ion attack, leading to rusting, damage to the concrete cover, and accelerated corrosion. Impressed current cathodic protection is an electrochemical technique to prevent steel corrosion. Its principle is to prevent corrosion by altering the electrochemical state of the steel: a cathodic protection current is supplied to the steel, making it a cathode and inducing a reduction reaction, thereby inhibiting oxidation on the steel surface and preventing or reducing corrosion.

[0003] Impressed current cathodic protection technology applies a cathodic current to the reinforcing steel through an external DC power supply. The negative terminal of the power supply is connected to the reinforcing steel, and the positive terminal is connected to an auxiliary anode (made of conductive material placed on or near the concrete surface). When the power is turned on, the current flows from the auxiliary anode through the electrolyte in the concrete pores to the surface of the reinforcing steel, lowering its potential to the cathodic protection range and inhibiting corrosion. This method allows adjustment of the current flowing to the reinforcing steel by adjusting the power supply output, making it suitable for large concrete structures such as large bridge piers.

[0004] Impressed current cathodic protection technology is widely used in various reinforced concrete structures, including residential buildings, office buildings, hospitals, schools, bridges, tunnels, docks, breakwaters, water towers, industrial plants, and parking lots. Especially in structures where steel reinforcement is corroded by chloride ions, such as those from the concrete itself, seawater, or de-icing salt, and in reinforced masonry structures, cathodic protection can effectively prevent cracking of the masonry structure caused by the expansion of corroded steel reinforcement.

[0005] Existing impressed current cathodic protection technologies utilize commonly available constant voltage and constant current output devices. However, because these devices are not specifically designed for cathodic protection systems, they perform poorly in low-current environments. Current products generally cannot stably output a constant current below 5 mA, and their accuracy is low under low current conditions. For example, a 30V adjustable regulated power supply available on Taobao, while theoretically capable of outputting a minimum current of 3 mA, exhibits significant current fluctuations at low current levels, failing to meet the requirements of impressed current cathodic protection. High-precision constant voltage and constant current output devices typically cost over 1000 yuan. Due to the large number of reinforcing bars in concrete structures, especially for seawater reinforced concrete, each reinforcing bar requires independent power output, often necessitating a large number of constant current power supplies. This places a significant burden on users. Furthermore, commonly available power supply devices are complex, bulky, and space-consuming, limiting their large-scale application. Utility Model Content

[0006] This invention addresses the shortcomings of existing technologies by proposing a high-precision, low-cost cathodic protection energizing device that enables large-scale protection of concrete structures, especially for cathodic protection of reinforced concrete structures made of sea sand, at extremely low cost.

[0007] The technical solution adopted in this utility model is as follows: A cathodic protection energizing device for protecting steel reinforcement in concrete structures from corrosion includes an assembly housing, a constant voltage to constant current source circuit therein, and an LED display device. The constant voltage to constant current source circuit mainly consists of an adjustable output positive voltage regulator LM317T and a variable resistor R. The power input terminal in of the regulator LM317T is connected to the positive terminal of a 30V DC power supply. The variable resistor R is connected between Vout and Vadj of the LM317T. The connection point between Vadj of the LM317T and the variable resistor R is connected to the LED display device. Simultaneously, the output terminal Iout of the cathodic protection energizing device is led out from the connection point between Vadj of the LM317T and the variable resistor R. The positive and negative terminals of the external 30V DC power supply, the output terminals Iout and Iout of the cathodic protection energizing device, and the LED display device are all housed in the assembly housing.

[0008] The cathodic protection power supply device for protecting steel bars in concrete structures uses a positive linear regulator LM7805CT to provide power to the LED display device. The power input terminal in of the LM7805CT is connected to the positive terminal of an external 30V DC power supply, the GND terminal of the LM7805CT is grounded, and the output terminal out of the LM7805CT is connected to the positive terminal of the LED display device. The negative terminal of the LED display device is connected to the device ground GND.

[0009] The cathodic protection energizing device for protecting steel bars in concrete structures has a filter capacitor connected between the other end of the variable resistor R connected to the Vout terminal of the LM317T and the device ground GND to filter out short-term current fluctuations.

[0010] The cathodic protection energizing device for protecting steel bars in concrete structures includes 1-n sets of constant voltage to constant current source circuits and an LED display device within the assembly housing, where n is a natural number greater than 1. Correspondingly, 1-n independent power port connectors are integrated into the housing, which can provide an independent and controllable protective current for the large number of steel bars inside the concrete structure.

[0011] The cathodic protection energizing device for protecting steel bars in concrete structures includes a panel (1) in the assembly housing. A constant voltage to constant current source circuit PCB board (2) is provided inside the assembly housing. An LED display device (3) is installed on the panel (1). The panel (1) is supported and installed above the PCB board (2) by four corner mounting posts (4). The constant voltage to constant current source circuit on the PCB board (2) is electrically connected to the LED display device (3). The constant voltage to constant current source circuit components, an external 30V DC power supply connector (5), and a cathodic protection energizing device output connector (6) are installed on the PCB board (2).

[0012] The cathodic protection energizing device for protecting steel bars in concrete structures has a variable resistor R set on the panel (2) of the assembled housing for easy adjustment. The variable resistor R is connected to the corresponding constant voltage to constant current source circuit components on the PCB board (2) through wires.

[0013] Beneficial effects of the utility model: 1. This utility model relates to a cathodic protection power supply device for protecting reinforced concrete structures from corrosion. It features a simple structure and low cost. It utilizes the inexpensive LM317T chip with a sliding resistor as a constant voltage to constant current power supply chip, and the LM7805 three-terminal voltage regulator chip as the power conversion chip for the display device. It is equipped with a RISYM brand LED voltage display screen. While fulfilling the cathodic protection function, the total cost of the structure does not exceed 20 yuan, far lower than constant current power supplies of the same precision on the market.

[0014] 2. This utility model relates to a cathodic protection energizing device for protecting reinforced concrete structures from corrosion. It features a compact structure and small footprint. All components used in this utility model are small electronic components, resulting in a small overall size similar to a 3x3 Rubik's Cube, facilitating installation and large-scale integration. Through its designed assembly ports, dozens of independent energizing ports can be integrated simultaneously, providing independent and controllable protective current to the large number of reinforcing bars within the concrete structure. Furthermore, the design includes a modular outer casing, effectively saving space and reducing installation difficulty when energizing the reinforcing bars in the concrete structure.

[0015] 3. This utility model relates to a cathodic protection energizing device for preventing steel reinforcement corrosion in concrete structures. It features high precision and accurately controllable current. Because this utility model is precisely positioned as an impressed current cathodic protection system, and considering the generally small constant current in impressed current cathodic protection systems, a low-cost, small constant current power supply is designed. By adjusting the internal sliding resistor, a high-precision constant current output can be achieved. Its actual accuracy is less than 0.1mA. Attached Figure Description

[0016] Figure 1 The diagram shown is a schematic of the constant voltage to constant current source circuit of the cathodic protection energizing device of this utility model. Figure 2 The figure shown is the assembly drawing of the housing of the cathodic protection energizing device of this utility model. Detailed Implementation

[0017] To make the technical concept and advantages of the invention clearer, the technical solution of this utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the following embodiments are merely preferred embodiments for explaining and illustrating this utility model, and should not be considered as, nor constitute a limitation on, the scope of patent protection claimed for this utility model.

[0018] Example 1: See Figure 1 , Figure 2 This utility model relates to a cathodic protection energizing device for protecting reinforced concrete structures from corrosion. It includes an assembly housing, a constant voltage to constant current source circuit, and an LED display device. The constant voltage to constant current source circuit mainly consists of an adjustable output positive voltage regulator LM317T and a variable resistor R. The power input terminal in of the regulator LM317T is connected to the positive terminal of a 30V DC power supply. The variable resistor R is connected between Vout and Vadj of the LM317T. The connection point between Vadj of the LM317T and the variable resistor R is connected to the LED display device. Simultaneously, the output terminal Iout of the cathodic protection energizing device is led out from the connection point between Vadj of the LM317T and the variable resistor R. The positive and negative terminals 5 for the external 30V DC power supply, the output terminal Iout and the negative terminal 6 of the cathodic protection energizing device, and the LED display device are all housed within the assembly housing.

[0019] This invention uses the LM317T as the constant voltage to constant current power conversion chip. A constant 1.2V voltage is maintained between the output terminals Vout and Vadj of the LM317T chip. By connecting a specific resistor R (an adjustable resistor), a constant current will be output from the device's output Iout port. The current calculation formula is: Iout = V / R = 1.2V / R (1) By adjusting the value of the resistor R, a constant current can be output. The current magnitude remains constant between 1.5mA and 100mA.

[0020] like Figure 1 As shown, this invention has a filter capacitor connected between the other end of the variable resistor R connected to the Vout terminal of the LM317T and the device ground GND. By adding a filter capacitor, short-term current fluctuations can be filtered out.

[0021] Example 2: This example is a cathodic protection power supply device for protecting reinforced concrete structures from corrosion. The difference between this example and Example 1 is that a positive linear regulator LM7805CT is used to provide power to the LED display device. The power input terminal in of the LM7805CT is connected to the positive terminal of an external 30V DC power supply, the GND terminal of the LM7805CT is grounded, and the output terminal out of the LM7805CT is connected to the positive terminal of the LED display device. The negative terminal of the LED display device is connected to the device ground GND.

[0022] An LM7805 three-terminal regulator is used to convert a 30V DC voltage to a constant 5V DC voltage to power the LED display device. The LED display device uses a RISYM brand LED voltage display screen, which also has a built-in voltage measurement function. It is connected to the current output terminal through the yellow port and can display the voltage input to the cathodic protection device in real time.

[0023] Example 3: See Figure 1 This embodiment describes a cathodic protection energizing device for protecting reinforced concrete structures from corrosion. The assembly housing includes a panel 1, and a constant voltage to constant current source circuit PCB board 2 is provided inside the assembly housing. An LED display device 3 is installed on the panel 1. The panel 1 is supported and installed above the PCB board 2 by mounting posts 4 at the four corners. The constant voltage to constant current source circuit on the PCB board 2 is electrically connected to the LED display device 3. Furthermore, the constant voltage to constant current source circuit components, an external 30V DC power supply connector 5, and a cathodic protection energizing device output connector 6 are installed on the PCB board 2.

[0024] In the diagram, 7 is the voltage regulator LM317T, 8 is the voltage regulator LM7805CT, and 9 is the adjustable resistor R.

[0025] The variable resistor R uses a sliding resistor with a maximum resistance of 2K ohms as the means of adjusting the constant current output. The resistance value R can be changed by turning the screw on the sliding resistor. The output current can be calculated using formula (1). According to the calculation, the minimum output current is: Iout = 1.2V / 20000 = 0.6mA. 0.6mA is the theoretical minimum current value. This current value has reached the limit of the LM317T chip. In order to protect the chip, it is recommended that the current be above 1.5mA.

[0026] For easy adjustment, the variable resistor R can be set on the panel of the assembled housing. The variable resistor R is connected to the corresponding constant voltage to constant current source circuit components on the PCB board through wires.

[0027] This utility model of cathodic protection energizing device can set n sets of constant voltage to constant current source circuits and LED display devices in the assembly housing, where n is a natural number greater than 1. Correspondingly, n independent power port connectors are integrated on the device housing at the same time, which can provide independent and controllable protective current for the large number of steel bars inside the concrete structure.

[0028] This invention designs a low-cost, small constant current power supply, precisely positioned as an impressed current cathodic protection system. Since the constant current in impressed current cathodic protection systems is generally small, this invention can achieve high-precision constant current output with an actual accuracy of less than 0.1mA. The circuit is simple and compact, and its cathodic protection energization for corrosion protection of reinforced concrete structures effectively saves space and reduces installation difficulty when energizing reinforced concrete structures.

Claims

1. A cathodic protection power supply device for the protection of reinforcing steel from corrosion in concrete structures comprising an assembled housing and within the housing a constant voltage to constant current source circuit and LED display means characterised in that: The constant voltage to constant current source circuit mainly consists of an adjustable output positive voltage regulator LM317T and a variable resistor R. The power input terminal in of the regulator LM317T is connected to the positive terminal of a 30V DC power supply. The variable resistor R is connected between Vout and Vadj of the LM317T. The connection point between Vadj of the LM317T and the variable resistor R is connected to the LED display device. At the same time, the output terminal Iout of the cathodic protection energizing device is led out from the connection point between Vadj of the LM317T and the variable resistor R. The positive and negative terminals of the external 30V DC power supply, the output terminal Iout and the negative terminal of the cathodic protection energizing device, and the LED display device are all housed in the assembly housing.

2. A cathodic protection current supply device for the corrosion protection of reinforcing steel in concrete structures according to claim 1 characterised in that: The LED display device is powered by a positive linear regulator LM7805CT. The power input terminal in of the LM7805CT is connected to the positive terminal of an external 30V DC power supply, the GND terminal of the LM7805CT is grounded, and the output terminal out of the LM7805CT is connected to the positive terminal of the LED display device. The negative terminal of the LED display device is connected to the device ground GND.

3. A cathodic protection current supply device for the corrosion protection of reinforcing steel in concrete structures according to claim 1 or 2, characterised in that: A filter capacitor is connected between the other end of the variable resistor R, which is connected to the Vout terminal of the LM317T, and the device ground GND to filter out short-term current fluctuations.

4. A cathodic protection current feeder for the corrosion protection of reinforcing steel in concrete structures as claimed in claim 1 or 2, characterised in that: The device housing contains 1-n sets of constant voltage to constant current source circuits and an LED display device, where n is a natural number greater than 1. Correspondingly, the device housing also integrates 1-n independent power port connectors to provide independent and controllable protective current for the large number of steel bars inside the concrete structure.

5. The cathodic protection current application device for the corrosion protection of reinforcing steel in concrete structures according to claim 3, characterized in that: The device housing contains 1-n sets of constant voltage to constant current source circuits and an LED display device, where n is a natural number greater than 1. Correspondingly, the device housing also integrates 1-n independent power port connectors to provide independent and controllable protective current for the large number of steel bars inside the concrete structure.

6. The cathodic protection energizing device for protecting reinforced concrete structures from corrosion according to claim 1, 2, or 5, characterized in that: The assembly housing includes a panel (1), and a constant voltage to constant current source circuit PCB board (2) is provided inside the assembly housing. An LED display device (3) is installed on the panel (1). The panel (1) is supported and installed above the PCB board (2) by the four corner mounting posts (4). The constant voltage to constant current source circuit on the PCB board (2) is electrically connected to the LED display device (3). Furthermore, the constant voltage to constant current source circuit components, an external 30V DC power supply connector (5), and a cathodic protection power supply device output connector (6) are installed on the PCB board (2).

7. A cathodic protection current supply for the corrosion protection of reinforcing steel in concrete structures as claimed in claim 6, characterised in that: The variable resistor R is set on the panel (1) of the assembled housing for easy adjustment. The variable resistor R is connected to the corresponding constant voltage to constant current source circuit components on the PCB board (2) through wires.

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