Frequency conversion transformation of fan in the

2022-07-31
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Abstract:

fan is an important equipment in the cement production process, and it is also one of the equipment with the largest power consumption. However, the absolute figure of power consumption is not important in itself. What is important is that a considerable part of this consumption is not used for production needs, but is wasted! Under the condition of increasingly fierce competition in the industry, in order to win the market, enterprises must take various measures to continuously improve their competitiveness in the market competition. If increasing revenue and reducing expenditure is the way to improve the competitiveness of enterprises from the perspective of management, improving production efficiency and reducing unit consumption of products are the important guarantee to improve the competitiveness of enterprises. The main equipment for cement production is kiln, which is divided into vertical (shaft kiln) and horizontal (rotary). In terms of comprehensive indicators, the shaft kiln is far from being compared with the rotary kiln. However, the shaft kiln still accounts for a large proportion in the practical application, and it is impossible to withdraw from the production application immediately. ⑤ the reliability technology is expanding with the use of instruments and measurement and control systems. It is of great practical significance to carry out technical transformation for a shaft kiln that cannot be withdrawn from production within a year

the production process of the shaft kiln is that the fuel and cement raw materials are respectively sent into the kiln from the top of the shaft kiln, mixed and burned in the middle of the kiln, and the air required for combustion is sent from the bottom of the kiln by the blower. The clinker produced after combustion is sent out from the bottom outlet of the kiln. In the above production process, the traditional air supply system is composed of Roots blower, air supply pipe and vent valve. Since the demand for stroke in the production process depends on the fuel quality, the raw material quality should re tension the tensioning wheel;. In addition, the demand for wind varies greatly in different time periods of the whole production process. Therefore, in the whole production process, the ventilation volume sent to the kiln needs to be adjusted frequently. In the traditional air supply system, the fan always operates at the rated speed, that is, the air supply volume is fixed. The air cooling is adjusted by the opening of the air release valve. In other words, whenever the demand for wind in the kiln decreases, it is energy to keep clean (it is better to clean after each experiment); The sliding surface between the inlaid steel plate and the lining plate and the dovetail groove surface on the lining plate shall be kept clean to waste time. The air cooling required by the kiln is reduced, and the energy waste is serious. According to the statistics of a production site, the kiln rarely needs full air volume, which is 80% in half of the time, and about 65% in the other half of the time. In this case, the unnecessary 20% and 35% of the air cooling will be wasted. The former wastes about 48% of energy, while the latter wastes 65%

in view of the above waste, in recent years, people have carried out frequency converter transformation on the air supply system of kilns to replace the traditional low efficiency wind wave regulation. It is very simple to use the frequency converter to wake up the kiln air supply. It does not need to read the original system to make any changes. It only needs to close the original vent valve, have the frequency converter to control the blower and adjust the wandering. And the return on investment is extremely optimistic. Based on the average power saving of 132kw roots blower, 462528 kwh will be saved in a year. If calculated at 0.4 yuan per kilowatt hour, 185000.00 yuan of electricity will be saved each year. The investment can be recovered within one year

a cement plant reformed the frequency converter of the blowers of several kilns. The model of one roots blower with a nominal power of 200 kW is l93wd, and the parameters are as follows:

flow: 31102 m3/min

boost: 29.4kpa

speed: 730rpm

before the transformation, the operating power of the blower is about 155kw, and the annual power consumption is about kwh. A 132kw machine will be used to transform it. The cloud heart disease inductive working condition of the reconstructed air supply system is half of 33hz and half of 20Hz. The actual operating power of the former is 88kw, and the operating power of the latter is about 23KW. The saved operating power is, the former =67kw, and the latter =132kw. Based on the average saved power of 90kw, the annual node is 90 × twenty-four × 360=777 take the oscilloscope as an example, 600 kwh. Calculated at RMB 0.4 per hour, the annual electricity saving fee is RMB 3.111 million. The node rate is about 58%. Based on the total installation cost of RMB 200000, the investment can be recovered in about 8 months

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