The Rational Utilization and Operation Points of the Coal-fired Equipment and Cooling Equipment in the Cement Production LineDate: 2019-06-25 Views:
Abstract: For the rotary kiln operator, when the feeding amount reaches the rated value, the system is gradually balanced. At this time, the operation of the kiln tail preheating and decomposition system of the rotary kiln is mainly to add and subtract the coal feeding amount in time and adjust the total exhaust volume in time according to the C4 outlet temperature and the raw material grinding and shutdown condition.
Key points of operation of kiln tail preheater and cold-cooling system
1. Kiln end preheater system of rotary kiln
For the operator of the rotary kiln: when the feeding amount reaches the rated value, the system is gradually balanced. At this time, the operation of the kiln tail preheating and decomposition system is mainly to add and subtract the coal feeding amount in time and adjust the total exhaust volume in time according to the C4 outlet temperature and the raw material grinding and shutdown condition.
1. Reduce the outlet temperature of preheater C 4 as much as possible, and achieve the purpose of reducing heat consumption. This paper mainly reduces the pull air volume of the system under the premise of ensuring the complete combustion of the kiln and the furnace, and sets the appropriate C1 outlet temperature and blanking temperature under the premise of ensuring the decomposition rate of raw materials into the kiln. Generally, the exit temperature of C _ 4 is controlled at 330 °360 ℃, and the outlet temperature of C1 is controlled at 840 ℃ ~ 870 ℃, usually about 850 ℃. The main factors affecting C1 cutting temperature are MFC coal feeding and system air consumption.
2. Ensure the temperature and pressure balance of the preheater. Mainly through the preheater raw feed valve to achieve material balance. That is, 0413 4 = 1, 2, 3, 4
3. Clean the preheater system regularly to ensure the smooth flow of the system. Generally according to the negative pressure situation at the end of the kiln, the site inspector is informed to clear the end of the kiln.
4. Adjust and shake the flip valve in time to keep the action flexible, so that the materials collected by the upper preheater can be evenly fed into the next preheater, so as to ensure the full heat transfer of the material and reduce the blockage probability.
5. Minimize the fluctuation of kiln coal weight and maintain the stability of the system.
Second, the structure type and normal operation of grate cooler
(1) structure type of grate cooler
The present type of grate cooler can be called second generation semi-inflatable beam grate cooler. The original designed cooling area is 114m2 and the cooling capacity is 4000t / d. In 1999, the production improvement was carried out. The grate cooler is divided into three segments and seven rooms, each of which has 24 rows of grate plates, one of which has 6 rows of fixed plates. There are 9 cooling fans, which are 052912 (one room inflatable beam), 0530123 (second room), 0531 (three room), 0532 (four room), 0533 (5 room), 0534 (6, 7 room).
(2) normal operation of grate cooler
1. Monitoring and control of material layer thickness.
The thickness of the material layer is mainly carried out by the pressure under the two-chamber grate. The lamination is generally controlled at 5.5 KPA and the thickness of the material layer is controlled at 500 m / 600 mm. The adjustment method is generally carried out by adjusting the speed of the grate plate. The second and third stages of the grate speed refer to one stage to set the set value of the ratio, the ratio is generally between 1.0 ≤ 1.4 and 1.1 ≤ 1.3. The thickness of the material layer on the fixed inflatable grate bed is adjusted by adjusting the air volume of the inflatable beam air supply fan on both sides of the grate cooler. The adjustment of the air volume in each chamber should be adjusted according to the thickness of the material layer and the cooling condition of the clinker to ensure that the heat exchange has enough air volume and should not be too large or too small;
2. Opening degree of waste gas baffle(0538 opening):the opening is determined by the difference between the air consumption of the clinker and the secondary air volume required by the rotary kiln, i.e. the opening of the baffle determines the amount of the secondary air entering the kiln when the cooling air volume is constant. The opening degree is small, the inlet air is large, the opening degree is large, and the inlet air is small. The opening is adjusted by the pressure of the kiln head cover. As for the relationship between secondary air entering the kiln and the exhaust air of kiln head, it can also be judged from the differential pressure of three and four chambers:this value is generally required to be below 100Pa during normal operation. If the value is greater than 100Pa, it means 0538 air rescue.
II. Factors affecting the high and low of the AQC wind temperature and the adjustment measures that the kiln operator can take
There are many factors that affect the air temperature of AQC. Generally speaking, the thickness of the material layer of the grate cooler and the air volume of the grate cooler are the main factors. It is mainly determined by the process operation condition of the kiln. The kiln operator can alleviate the high or low air temperature of the furnace by properly adjusting some parameters. The factors that usually cause the high air temperature at the entrance of AQC are as follows: (1) the material is crossed in the kiln, the block is dropped, the ring in the kiln makes the material fall unevenly, the grate freezer makes snowman, etc.; (2) the feed quantity increases, the air volume and other parameters are not adjusted; (3) due to the coarse pulverized coal, the coal feeding at the kiln head is not fully burned, and the unburned pulverized coal particles burn with the clinker entering the grate cooler, resulting in high temperature. Kiln exercise The methods that the crew can take are as follows: for 1, 2 items, the air volume can be increased by 0531, the opening of the baffle can be increased by 0534, the air volume in the low temperature section can be increased, and the grate speed can be properly accelerated so that the thick material layer can be sent away as soon as possible (the above operations should be considered according to the current and so on). For the three items, the kiln speed can be reduced properly, and the coal can be burned in the kiln, so that the thickness of the grate cooler layer can also be thinned. In addition, if the air temperature of AQC is too high for a long time, the kiln preheater operator can also increase the rotating speed of 0506 of the exhaust fan at the end of the kiln and increase the secondary air volume of the kiln.