Pneumatic contactor of large-scale motor for mine

Abstract

The invention provides a pneumatic contactor of a large-scale motor for a mine. The pneumatic contactor is provided with an arc extinguishing cover, the interior of the arc extinguishing cover is divided into an upper space and a lower space through a transverse partition plate in the middle of the interior of the arc extinguishing cover, and a driving air cylinder and an electromagnetic valve forcontrolling the driving air cylinder are installed in the lower space; an insulating supporting plate is arranged at the upper end of a piston rod of the driving cylinder; three groups of moving endwiring boards which are arranged side by side are fixedly arranged on the insulating supporting plate; two ends of each group of moving end wiring boards are respectively provided with a moving contact; the two sides of each moving end wiring board are respectively provided with a static end wiring board corresponding to each moving contact, each static end wiring board is erected through an insulating supporting plate arranged on the transverse partition plate, one end of each static end wiring board extends out of the side wall of the arc extinguishing cover, and the other end of each staticend wiring board is provided with a static contact. The contactor provided by the invention greatly reduces the use and later maintenance cost, is low in noise and high in safety, and has a very goodfield actual use value.

Description

technical field [0001] The invention relates to the technical field of power system equipment, in particular to a large-scale motor pneumatic contactor for mines. Background technique [0002] At present, the circuit breakers used in the main control circuit (low-voltage electrical appliances 36V ~ 380V) on the market are all inductive magnet type. The electric energy is used to generate electromagnetic attraction through the inductive coil to realize the start and stop of the motor. The electromagnetic coil is maintained by electric energy. , its disadvantages are as follows: [0003] 1. High energy consumption: the magnet coils of a 200A AC contactor control circuit are all above 0.2kW. Large enterprises generally operate continuously. Calculated according to 24 hours, 0.2kW*24=4.8 degrees, many large mining Enterprises with an annual output of one million tons of concentrate, one pump room has hundreds of motors, the average power is 200kW, the supporting contactor is ab...

AI Technical Summary

Problems solved by technology

[0003] 1. High energy consumption: the magnet coils of a 200A AC contactor control circuit are all above 0.2kW. Large enterprises generally operate continuously. Calculated according to 24 hours, 0.2kW*24=4.8 degrees, many large mining Enterprises with an annual output of one million tons of concentrate, one pump room has hundreds of motors, the average power is 200kW, the supporting contactor is above 0.3kW, and the daily energy consumption is 0.3kW*24=7.2 degrees, then 100 The annual consumption of Taiwan is 7.2 * 100 * 30 days * 12 months = 27920 kWh. Calculated at 1 yuan per kWh, the annual electricity bill for a small pump room control loop magnet coil in a large enterprise is as high as 27920 yuan. , which is a conservative estimate, it can be seen that its energy consumption is still quite large

[0004] 2. Since the current mine motors are very unstable in field power supply in the actual environment, the electromagnetic force of the control circuit will be unstable, which often causes the main circuit terminals (contacts) to burn out, and then burns out the main equipment (motor). One 200kW The price of the electric motor is tens of thousands of yuan, and the repair and material costs are tens of thousands of yuan. The power distribution cabinet will also explode due to the short circuit of the terminal. The price of a single cabinet is tens of thousands of yuan. A large The 300A contactor costs several thousand yuan, and the labor cost is also a lot. In combination with various circumstances, once the terminal is burnt out, the loss will be huge, and this phenomenon often occurs in mine sites

[0005] 3. Since the electromagnetic contact surface has been working in a bad environment for a long time, dust and oil stains left on the plane will produce eddy current vibration, which does not affect the terminal itself, and the noise is quite loud. When workers enter the electromagnetic station for maintenance, their ears will be hurt. No, because it is continuous production, and it cannot be completely stopped for maintenance, only partial power failure for maintenance. Considering the production cost, it is not possible to replace all the contactors that generate noise. After the overhaul is completed, it will return to its original state and produce noise after a few days, because the internal structure has been out of balance at this time

[0006] 4. Increased maintenance intensity: Every time there is a problem with the contactor, just use a simple way to deal with it. If the terminal is burnt out, simply rub it with sandpaper or file it with a file. It can be used at that time, but the problem is not there. The fundamental solution, of course, is that the production line cannot be stopped for too long, which will have serious consequences

[0007] 5. Terminal heat is very serious

Everyone knows that heat energy is supported by energy materials such as coal, electricity, oil, etc. The heat of the terminal is caused by excessive contact resistance, and because of excessive current and material limitations, it is unrealistic to use silver as the terminal. Only silver-plated ones are used. The method is used for a long time, and the silver is ground flat, and due to the instability of the on-site power supply voltage, the electromagnetic force is unstable, the tight fit of the terminals has changed, and the vibration of the terminals can cause the terminals to heat up. In actual use, the newly installed terminals heat up. The temperature is 30℃~50℃. After half a year, the heat of the terminal will reach 100℃~200℃, and the heat loss of the terminal will be very large. This is all non-kinetic energy consumption, and what is more serious is that it will burn out Major equipment such as electric motors

[0008] 6. There are potential safety hazards. For example, if the motor is burned out, the wires must be removed and the main circuit replaced. However, the ground of the pump room is full of sewage, the temperature is high, and the insulation value is very low. There are great potential safety hazards.

[0009] 7. It is difficult to find terminal problems through point inspection of the electromagnetic station, because there are arc extinguishing covers, it is impossible to open the arc extinguishing cover of each circuit breaker for point inspection, except for the overhaul of the electromagnetic station, this kind of problem is common all over the world They all exist, but we must try our best to achieve the best cost performance.

[0010] 8. In the era of competition, it is difficult to guarantee the quality of circuit breakers. Take the terminals as an example. A common 300A terminal may only cost tens of yuan, while a high-quality silver terminal costs thousands of yuan. Unless it is specially customized, it is currently still There is no good way to solve the cost-effectiveness of high-quality terminals

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