Application of the hottest alpha2000 frequency con

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Application of alpha2000 frequency converter in cement industry. With the continuous improvement and development of frequency conversion technology in recent ten years, the performance of frequency conversion and speed regulation is becoming more and more perfect. It has been widely used in different fields by engineers and technicians in different disciplines and industries. It has brought considerable economic benefits to enterprises and promoted the automation process of industrial production. Cement manufacturing industry is a major energy consumer in the building materials industry. Reducing energy consumption and improving product quality are important measures to improve the competitiveness and economic benefits of enterprises. Energy saving and consumption reduction has become the focus of every enterprise manager

our engineering and technical personnel have conducted long-term follow-up and special research on the air supply system of the mechanical shaft kiln, the unloading system of the mechanical shaft kiln and the cement powder separation system in small and medium-sized cement plants. The developed complete set of variable-frequency speed control device has been applied in dozens of cement production lines. With its reasonable design, compact structure, convenient installation and commissioning, perfect protection function, stable and reliable operation, and obvious power saving effect The production process can be significantly improved and other advantages have won wide praise

II. Frequency conversion transformation of screw blower of shaft kiln

1. analysis of working conditions

taking Enping Juntang cement plant as an example, there are two roots blowers in the plant, one of which has a motor power of 215kw, rated voltage of 380V and rated current of 415a; The other is 185KW, with rated voltage of 380V and rated current of 367a. During the design of Roots blower for shaft kiln, the air volume required for maximum production is generally considered, and a certain margin is reserved, which is generally about 20%, so as to prolong the service life of the blower and motor. In addition, the air supply required by the shaft kiln at different stages of the production process is also different, so the air volume and air pressure are often too high during production. At present, the operating workers generally adjust the inlet air volume according to the different stages of the production process. The measure to adjust the air volume is to open a vent valve on the air outlet pipe of the fan. By adjusting the opening of the vent valve, the air supply volume can be adjusted. In this way, a large amount of excess air volume is discharged into the atmosphere, resulting in a waste of energy. In the process of ventilation, there is a lot of noise

2. solution

for the above working conditions, our company believes that the following transformation schemes can be adopted:

(1) the original drive system can be transformed into a variable frequency speed regulation drive system. The frequency converters selected for the two sets of variable frequency speed regulation drive systems are respectively alpha2000 3220g and alpha2000 3200g. The principles of the two systems are the same. The air supply system after frequency conversion transformation is a double loop control system formed by adding a set of frequency conversion speed regulation system in parallel with the original control system on the basis of retaining the control system with a total investment of 1billion yuan planned in the original step-down startup project. Its characteristic is that the dual control circuits are standby for each other, with high reliability, and the equipment does not need to be shut down during maintenance, so as to ensure the continuous production. Close the vent valve and change the air supply volume of the system by changing the speed of the motor, so as to achieve the purpose of energy saving and consumption reduction

(2) in order to facilitate the kiln surface operators to control the air volume, the frequency converter is set as the terminal control, the control signal is led to the kiln surface, and an operation panel is installed on the kiln surface. By operating the operation panel to promote the construction of Lunan high tech chemical industry Park and the new chemical material technology innovation and industrialization base of Chinese Academy of Sciences, the start and stop of the fan can be controlled and the air supply can be adjusted. The operators can adjust the air volume at will according to the calcination conditions. A tachometer is installed on the operation panel to indicate the fan motor speed

3. users benefit from the transformation

(1) improve the production process. After the transformation, the air supply can be smoothly adjusted according to the different stages of production, so as to ensure the product quality

(2) improve the production environment. Since the frequency converter can arbitrarily adjust the fan motor speed, it can accurately adjust the air volume according to the required air volume without bypass ventilation, which greatly reduces the noise caused by exhaust and reduces the cement dust pollution

(3) reduce equipment maintenance workload. Since the frequency converter has a soft start function, there is no large current impact when the motor is started, which extends the service life of the equipment and greatly reduces the maintenance workload

(4) energy saving and consumption reduction. After the transformation, the power saving effect is remarkable. According to the original equipment and production process, the power saving rate can reach 15%-40%. Generally, all the investment can be recovered in 6 ~ 12 months, the investment recovery cycle is short, and the comprehensive benefit is considerable

4. parameter setting of Luoci fan frequency converter

III. frequency conversion transformation of shaft kiln unloading system

1. working condition analysis

in order to make the "three balances" (i.e. feeding, air supply and unloading) in the cement sintering process, shaft kiln producers generally choose the slip motor as the power for the tray tower unloading device. Under the same conditions, the motor consumes 20% more power than the ordinary y system train motor, and has soft adjustment characteristics and poor load carrying capacity. In the cement industry with serious dust, slip head failures are frequent and maintenance is difficult. It is very inappropriate to use 20% more power in exchange for soft adjustment characteristics. At present, the plant has 2 unloaders, with a power of 22KW, a speed of 1460 rpm, and a rated current of 45A. The actual running speed of the slip speed regulating motor is 400 rpm. The slip speed regulating motor is typically regulated by the slip rate. With the decrease of the speed, the slip rate increases, and the resulting increase in the slip power of the inner rotor is all transformed into heat loss, resulting in a significant decline in the system efficiency

2. transformation scheme

drill and assemble screws on the slip head of the 22KW slip speed regulating motor to make the motor shaft and the load shaft rigidly connected. If the slip motor is fast enough to reach its service life, it can be replaced with an ordinary cage motor, and the modified motor can be started and dispatched through the frequency converter. The tray tower unloading device is a typical constant torque load. The efficiency of the variable frequency speed regulation system instead of the original slip speed regulation system is greatly improved. The lower the load speed is, the more significant the energy-saving effect of the variable frequency system is

3. user benefit

(1) after the frequency conversion transformation, the power saving rate of Hubei new material industry has an average annual growth of 17.6% to 1 Maximum experimental torque: ly10nm, 20nm, 50nm, 100nm, 200nm35% or more, with significant benefits

(2) the system is more convenient to use. After the frequency conversion transformation, the speed regulation performance is much better than the slip speed regulation, the speed regulation characteristics are hard, and the load capacity is improved

(3) greatly reduce the workload of equipment maintenance, save more than 50% of the maintenance cost, and ensure the continuous production

4. parameter setting of unloader frequency converter:

IV. energy saving transformation of powder concentrator

1 Working condition analysis

according to the different cement grades, the fineness of the finished cement powder is required to be different. However, the process of changing the fineness of the old powder concentrator is quite troublesome. It is not only necessary to stop production, but also to disassemble the powder concentrator and adjust the number and angle of each group of fans on the coaxial line. There is no certain standard for this process, so the comparative test can only be conducted once according to experience, and the process is repeated every time: the startup group adjusts the fan blades and installs the unit for trial selection and inspection of fineness -- until the selected powder meets the required fineness

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