Mixing machinery is widely used in the production process of chemical, pharmaceutical, food, water industry, plastics and other industries.When designing the mixing machinery, a certain margin is considered according to the requirements of the working conditions.In the actual use of the mixer, the It is not necessary to work at the maximum speed, and it can work at a non-full load state for a lot of time; traditional mixers usually do not adjust or use mechanical speed regulation; mechanical speed regulation will increase the loss of the mixer and make the mixer work at the same time In the fluctuating state, it also makes the mixer equipment work in the state of "big horse-drawn trolley", which is very uneconomical.
KE300A frequency converter is used to control the speed of AC motor.This speed regulation method has high efficiency and energy saving, which is better than any previous speed regulation method.Therefore, by adding to the mixer equipment, many problems in the use of traditional mixers can be solved once and for all, and the investment can be recovered through energy saving.
A mixer is a machine that puts a variety of raw materials into a shaft with blades and rotates in a cylinder or tank for stirring and mixing to make it a mixture or a suitable consistency.According to the characteristics of the stirring material and the time of adding other substances, the stirring speed is also different.At present, a hydraulic coupling is used for stirring control.However, the hydraulic coupling is a mechanically inefficient speed regulating device, and there are still many defects:
电机 Electric machinery
搅拌机工艺示意图 Process diagram of mixer
(1) The speed regulation range is low, and the maximum speed regulation range of the hydraulic coupling is 4:1.
(2) Accuracy of speed regulation, the speed regulation accuracy of the hydraulic coupling is poor, and the speed fluctuates greatly.
(3) The efficiency of the hydraulic coupling is low, and its efficiency is proportional to the speed ratio.The lower the speed of the load, the lower its efficiency.
(4) Since the hydraulic coupler is a flexible connection, there is a fixed slip rate, that is, the slip rate of the hydraulic coupler is ≥ 3%, and the maximum can only reach 97% of the motor speed.
(5) The hydraulic coupling belongs to the direct starting type, and the starting current of the motor is about 4-7 times of the rated current, which has a great impact on the power grid.
(6) The reliability of the hydraulic coupling is poor, especially oil leakage and broken gears.
(7) The maintenance workload is heavy.
(8) Since the hydraulic coupling is connected between the motor and the fan, once the hydraulic coupling fails, the load cannot operate, and the continuity of production cannot be guaranteed.
Frequency conversion control technology is the most important technology of electrical automation control at present.It has played an important role in the equipment control of all walks of life.It is an inevitable development trend for the application of mixers, and it will definitely become the most important and most important technology in the automation of mixing process control.As the core component, the frequency conversion control technology of the mixer will bring the following innovations:
1. Realize energy saving through frequency conversion speed regulation
In the actual work process, according to the characteristics of the mixing material and the time of adding other chemical substances, multiple speeds can be set, up to eight different speeds can be achieved.At the same time, the program operation function of the frequency converter can also be used.Up to seven different speeds and different time automatic program operation modes can be set, which greatly reduces the labor intensity of workers and improves production efficiency.
2. The power factor of the grid side is improved
When the original motor is directly driven by power frequency, the power factor is low at light load (except for those with compensation).After adopting the frequency conversion speed regulation system, the power factor of the power supply side can be increased to above 0.9, and the power factor can be greatly improved without reactive power compensation device.Reducing reactive power and meeting the requirements of the power grid can further save the operating costs of upstream equipment.
3. Improve the use efficiency of the mixer, save electric energy, reduce equipment operating costs, and ensure the progress of production tasks to the greatest extent
The most basic and important point in the frequency conversion speed regulation technology is to realize the stepless speed regulation that cannot be realized by the power frequency.It can realize the speed regulation below the power frequency of the mixer equipment, so that the speed can adapt to the best working condition and quickly adapt to the load change., always keep the output of the motor running with high efficiency.Mechanical losses will be further reduced, saving valuable electrical energy.
4. Save electricity through the V/F function of frequency conversion itself
In the case of ensuring the output torque of the motor, the V/F curve can be automatically adjusted.Reduce the output torque of the motor, reduce the input current, and achieve an energy-saving state.
5. The motor can be soft-started, and the current does not exceed 1.2 times the rated current of the motor when starting, and the service life of the motor is extended
In the whole operating range, the motor current is small when starting, and the power consumption is 80% smaller than that of starting with a contactor, and the motor can ensure stable operation.It is self-evident that the damage caused by the current impact and the electric transient when the mixer with large inertia is started at the traditional power frequency is self-evident.The impact on the power grid saves electricity costs, and also reduces the impact of the startup inertia on the high inertia of the equipment, prolonging the service life of the equipment.
6. Powerful protection function and strong ability to adapt to grid voltage fluctuations
The general protection function of the frequency conversion speed regulating device is comprehensive.It can prevent the damage to the motor caused by sudden changes in the power grid, effectively protect the inverter and the motor when the grid-side power supply fails, and effectively prevent the fault from spreading to the power grid when the motor load fails, and can protect the motor to the maximum extent.When the mixer is overloaded, the frequency will be automatically reduced to protect the normal operation of the equipment and the motor.
7. The use of frequency conversion speed control device can improve the level of automation and provide a bottom-level solution for the factory to achieve a high degree of automation
In the actual operation of the mixer, it is often noisy, dusty, and the work intensity of the workers and the environment are poor.If the frequency conversion speed control device is used, the electrical transmission equipment can be placed at a position far away from the mixer, which is more convenient and safe to operate.Real-time Data monitoring can also be performed in an environment away from noise.
With its excellent performance, the KE300A frequency converter greatly improves the stability and safety of the traditional mixer, and reduces the maintenance work of the equipment.The control system customized for the mixer integrates many safety technologies and automatic control functions, provides a complete set of electronic control solutions for mixer equipment manufacturers, and can also rejuvenate the old mixer. Since it was launched and used, it has won unanimous praise from users, and it has also solved the problem of backward electronic control of many machinery manufacturers, and achieved good social and economic benefits.