The crushing of feed raw materials is a very important link in feed processing. By crushing, the large total surface area of raw material particles per unit mass can be increased to increase the solubility of feed nutrients in animal digestive juices and improve the digestibility of animals. At the same time, the small size of pulverized raw materials has a very important impact on the difficulty of subsequent processes (such as granulation, etc.) and the quality of finished products. Moreover, the size of pulverized grain size directly affects the production cost. In the production of powdered compound feed, the power consumption of pulverized process is about 50% ~ 70% of the total power consumption. The smaller the particle size, the better it is for animal digestion and absorption, and the better it is for granulation, but the corresponding increase in power consumption, and vice versa. The total amount of pulverized processing in China is more than 200 million tons per year. As the main equipment of the feed industry, the feed grinder is an important factor for the formation of feed quality, feed remuneration and feed processing cost. Therefore, it is an important problem in feed production to master crushing technology and choose proper crushing machine.

Variable frequency speed regulation technology is by frequency converter to change the machine equipment operation parameters and has obvious energy saving effect, partially used in feed industry but it is not popular, through the introduction of the article, can cause feed companies and feed machinery and equipment manufacturers to strengthen a variety of mechanical equipment adopts frequency control of motor speed technology test research work, accelerate the popularization and application of variable frequency speed regulation technology.

There are a lot of motors used in feed processing machinery in large and medium-sized feed mills, mainly three-phase ac induction asynchronous motors. Some machines need to adjust the speed to meet the needs of different working conditions, but also the main measures to save energy. In recent years, with the maturity of inverter production technology and the increasingly wide range of inverter application, the use of inverter to carry out technical transformation of motor power supply has become an important means for enterprises to save energy, reduce consumption and improve efficiency.

The fixed frequency of power supply supplied by China's electric power department is 50 Hz, and the rotating magnetic field speed of ordinary three-phase ac induction induction motor is also fixed, so the speed cannot be changed (adjusted). At present, the speed regulation methods of three-phase induction induction motors mainly include changing the logarithm of magnetic pole p (speed regulation by changing pole), changing slip s (speed regulation by changing slip) and changing frequency f (speed regulation by frequency conversion). Two-speed motor: it is possible to change the number of magnetic poles of the motor by changing the connection method of the motor coil to change the speed of the motor, that is, fast and slow, two kinds of fixed speed. (2) electromagnetic speed control motor: with the electromagnetic speed control controller, manually slide the resistor knob or through the load controller to change the motor speed (120 ~ 1 200 r/min). (3) ordinary three-phase induction induction induction motor or frequency conversion motor: through the frequency converter to change the power supply, the motor rotating magnetic field speed change, also change the motor speed, speed range wide.

Inverter is a power control device that converts power supply into another frequency by the on-off action of power semiconductor devices.

Principle of variable frequency speed regulation of frequency converter:

The rotating magnetic field speed of induction motor: n1(r/min)=60 f/p, where: f -- power supply frequency (Hz); P -- logarithm of the magnetic pole of the motor; The speed of the motor is n<n1.< span=""> The rotation speed of the magnetic field is proportional to the power frequency and inversely proportional to the logarithm of the magnetic pole. The logarithm of the magnetic pole of the motor is relatively fixed, so it is not suitable to change the value to adjust the speed of the motor. Therefore, the speed of the motor can be changed by changing the power frequency with the frequency converter.</n1.<>

The main functions and features of AMB300 inverter:

With vector control and V/F control functions; Torque automatic lifting function, low frequency and large torque output function; Built-in PID closed-loop control function; Built-in rs-485 interface, can be networked with the computer control; With a variety of protection functions (overvoltage, undervoltage, overcurrent, phase miss, overload, overheat, reverse protection, etc.). It can implement soft start and slow stop of the motor, reduce the impact of starting current on the power supply, and replace the step-down start equipment and protection equipment of the high-power motor. It is very convenient to control the positive and negative rotation of the motor, and a series of advantages such as wide range of speed regulation, high transmission efficiency and remarkable power saving.

1, can realize the feed mill, granulator and extruder before the feeder frequency regulation.

According to the current situation of the main motor, adjust the output frequency of the frequency converter, change the speed of the feeder, change the feeding amount, to avoid overloading and burn out the motor

2. Frequency converter is used to control the speed of the crusher, which can meet the requirements of crushing particle size of different kinds of feed.

All kinds of crusher due to the difference in the moment of inertia, hammer and screen wear different, different kinds of crushing feed, different particle size requirements, requirements for the speed of the crusher is different. According to the test, without changing the feeding amount, adjust the speed of the crusher through the frequency converter, and find out the speed of the motor when the minimum current is the speed of the speed. The application of this method can increase the output by 5% ~ 15% and reduce the power consumption by 5% ~ 15%. With the wear of hammer and the change of material, the speed point should be adjusted accordingly. Other aspects such as micro pulverizer, micro powder grading equipment, liquid adding equipment, negative pressure suction and dust removal can be used to change the operating parameters of variable frequency speed control technology.

3, frequency control technology in the feed industry has been widely used.

According to the investigation, some machinery is very need to use frequency converter control, mechanical frequency conversion speed regulation technology performance parameters are appropriate, need to be determined after a large number of production tests, so that the use of frequency converter for frequency conversion speed regulation will bring huge economic benefits for each enterprise.

The core technology of frequency converter is mastered by developed countries, and the price of imported frequency converter is very high. Some domestic high-tech electrical equipment manufacturers through the introduction and absorption, has been able to develop and produce good performance of the frequency converter, the price is only 1/3 ~ 1/2 of the import. At present, the price of frequency converter is still higher than that of ordinary control and protection electrical appliances. Relevant technicians are required for installation and debugging and training of field operators. But through the frequency conversion speed adjustment to adapt to the needs of different working conditions, improve the output and processing quality, reduce power consumption, save the cost, after 1-2 years can recover the technical transformation investment, and increase the economic benefits of the enterprise. The frequency converter is a kind of mature technical equipment, is the feed mill energy saving transformation ideal equipment, has the very high promotion value, the general feed enterprises should raise the understanding, pays attention to the technology introduction work, speeds up the frequency control technology promotion application. In the application, reasonable type selection, correct installation, do well the parameter setting and debugging of the frequency converter, in order to achieve good results.