Technology | fourth-generation tail roller broken upgrade of grate cooler
Technology | fourth-generation tail roller broken upgrade of grate cooler
Technology | fourth-generation tail roller broken upgrade of grate cooler
A company of 5000 t/d clinker production line configuration in the fourth generation of stepping type grate cooler, form a complete set of the tail set roller crusher (roller), along with the progress of the clinker burning technology, the grate cooler area is lesser, limits the further from consumption of production line, promotive slightly enhancing yield, the grate cooler clinker temperature on the high side and accompanied by the red material, and grate cooling mechanical and electrical consumption and maintenance amount is larger. In order to meet the requirements of energy-saving production, the company will use Smith cross bar grate cooler technology to upgrade the line cooler in early 2021. This paper summarizes the transformation for reference.
1. Analysis of existing problems
The firing system of the production line is equipped with ф4.8m×72m rotary kiln, five-stage double-series preheater and grate cooler for the fourth generation of stepping grate cooler. The main problems before the transformation are as follows:
(1) The second and third air temperature of grate cooler is not high, and the second air temperature is about 1050~1100℃, and it is unstable.
(2) The grate cooler covers an area of only 138.3m². The outlet clinker temperature of the grate cooler is often higher than 120℃, and red material sometimes appears.
(3) Power generation per unit of clinker waste heat is low.
2. Solutions
(1) Automatic air volume control valve, save wind and electricity, help to ensure the thermal stability of the system;
(2) With the snowman elimination device, so that the grate bed layer is more stable;
(3) High heat recovery efficiency, generally guaranteed above 75%, to avoid the phenomenon of high temperature of outlet clinker;
(4) The use of decentralized independent single row hydraulic drive, high reliability of operation, greatly reduce the risk of kiln shutdown due to grate cooler failure;
(5) The use of cross rod conveying clinker, its high conveying efficiency, less wearing parts, low maintenance;
(6) Modular grate bed, grate plate fixed, only cooling effect, high reliability;
(7) The use of special sealing structure, no leakage, no leakage conveying device, low maintenance;
(8) Strong crushing capacity of roller, large diameter of crushing roller, and equipped with "lower roller" (increased crushing Angle, strong crushing capacity of large materials), frequency conversion speed regulation.
Concrete plans: overall demolition of the grate cooler ontology and cooling fan, according to Smith company design the shell at draught on docking with the waste heat power generation and waste gas outlet, the overall change of a cross bar grate cooler, make grate cooler and roller broken again, continue to use the original inclined zipper machine foundation, new grate cooler outlet discharge valve is directly linked to the inclined zipper machine.
3. Program implementation
The transformation will be carried out during the overhaul period after the Spring Festival of 2021, lasting a total of 40 days, to ensure the re-ignition and feeding of the production line to the maximum extent. So far, production has been stable.
The modification of grate cooler in front of middle roller break is shown in the diagram. For the grate bed and intermediate crusher after the new grate cooler roller is broken, the foundation shall be excavated and made again. The grate bed foundation of the section after roller breaking is about 2.3m below the ground. The base elevation of the zipper remains the same in order to minimize civil excavation. The transformation of the new grate cooler after the middle roller is broken is shown in the figure.
4. Technical transformation effect
After modification, the equipment runs stably, and the secondary air temperature runs stably above 1150℃. See the equipment configuration and effect comparison before and after the cooling machine transformation.
Grate cooler is one of the core systems of sintering equipment, which not only undertakes the tasks of clinker cooling and conveying, but also improves the quality of clinker, the grillability of clinker and the efficiency of heat recovery. Its use effect will directly affect the whole firing system operation rate, coal consumption, power consumption and other important indicators. Because of the importance of grate cooler, many cement enterprises are carrying out the optimization and transformation of grate cooler to further optimize the firing system index. This technical modification proves that compared with the tail grate cooler with broken roller, the central roller breaker can 100% ensure that the outlet clinker temperature of the grate cooler is lower than the ambient temperature +65℃, and is basically not affected by kiln conditions and clinker granation. Due to the position of the central roller breaker, more waste heat will be used for power generation, rather than wasted in nothing.
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